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Sindh Mdcat 2022 — Solved Past Paper with Answers

All 200 MCQs from Sindh Mdcat 2022, solved with the correct answer highlighted and a full explanation for every question. This is a free MDCAT Sindh / DUHS past paper — no signup, no ads. Practise it interactively in timed mode, drill more with free MDCAT MCQs, or browse all Sindh / DUHS papers.

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Q1. Fill in with appropriate the preposition. We saw a cricket match _ the school stadium.

A. Over
B. Of
C. At✓
D. On

Explanation: The preposition "at" is commonly used to indicate a specific location or place. In this context, "at" would be the most appropriate preposition. Saying, "we saw a cricket match at the school stadium", means that you witnessed the cricket match while being physically present in the school stadium.

Why the other options are wrong

A. The preposition "over" indicates movement or position above something. However, it is not the most appropriate preposition to use in this context.
B. The preposition "of" expresses possession or association. However, it doesn't fit well in this sentence. Saying, "we saw a cricket match of the school stadium", suggests that the cricket match somehow belongs to or is associated with the school stadium, which is not the intended meaning.
D. The preposition "on" typically denotes position or contact with a surface. While it can be used in certain contexts related to events or performances, such as "on stage" or "on television," it doesn't work well in this sentence. Saying, "we saw a cricket match on the school stadium", implies that you saw the match while physically positioned on top of the stadium, which is not the intended meaning.

Q2. I _ make an appointment with the dentist soon.

A. Making
B. Had take
C. Make
D. Made
E. Will✓

Explanation: Option E is correct. I "will" make an appointment with the dentist soon is the correct answer.

Why the other options are wrong

A. This option uses the present participle form of the verb "make" (making). However, in this sentence, we need the base form of the verb because it follows the auxiliary verb "will" (Option E). So, "making" is not the correct choice in this context.
B. This option combines the past tense of the auxiliary verb "have" (had) with the base form of the verb "take." However, this combination does not fit well in the sentence structure. Since the sentence is in the present tense ("I make"), using "had take" would create a mismatch in verb tenses. Therefore, Option B is not the correct choice.
C. This option uses the base form of the verb "make," which is the correct choice in this context. The sentence is in the present tense, and "make" agrees with the subject pronoun "I." So, "make" is a suitable choice for this sentence.
D. This option uses the past tense of the verb "make" (made). However, since the sentence is in the present tense, using the past tense would create a tense inconsistency. Therefore, Option D is not the correct choice.

Q3. Due to his negligence, he failed in the examination.

A. He failed
B. In the examination
C. His negligence
D. No error✓
E. Due to his negligence

Explanation: There is "no error" in the sentence. Thus option D is the correct answer. It means that all the provided options A, B, C, and E are correct and necessary for the sentence. In that case, the sentence "Due to his negligence, he failed in the examination" is grammatically and structurally sound.

Why the other options are wrong

A. This option refers to the subject of the sentence, indicating that "he" is the one who failed. It is a valid and necessary part of the sentence. Without this option, the sentence would lack a subject and wouldn't make sense.
B. This option provides additional information about where the failure occurred, specifying that it happened "in the examination." It serves as a prepositional phrase and is an essential part of the sentence. Without this option, the sentence would lack context and specificity.
C. This option explains the reason for the failure by attributing it to "his negligence." It is a dependent clause that clarifies the cause and is necessary for conveying the intended meaning of the sentence. Without this option, the sentence would not provide an explanation for the failure.
E. This option functions as a subordinate clause and introduces the reason for the failure, emphasizing that it occurred "due to his negligence." It provides a clear cause-and-effect relationship in the sentence and connects the negligence to the failure.

Q4. Which sentence uses capital letters correctly?

A. I will be moving To china.
B. i will be moving to China.
C. i will be Moving to china.
D. I will be moving to China.✓

Explanation: Option D is correct. The capitalization is used correctly in this sentence for the following reasons:Sentence beginning: The pronoun "I" is capitalized because it is at the beginning of the sentence. In English, the first word of a sentence is always capitalized.Capitalizing "moving" is not necessary: The word "moving" is not a proper noun, and it is not the first word of the sentence or part of a title. Therefore, it does not require capitalization.Capitalizing "to" is unnecessary: In this context, the word "to" is a preposition, which typically does not require capitalization unless it is the first word of a title or sentence.Therefore, the correct capitalization for the sentence is "I will be moving to China."

Why the other options are wrong

A. In the sentence "I will be moving to China," the capitalization is used correctly for the following reasons:Proper noun: "China" is a proper noun referring to a specific country. Proper nouns, such as the names of countries, cities, or people, should be capitalized.The sentence beginning: The pronoun "I" is at the beginning of the sentence, which is another instance where capitalization is required.Capitalizing "to" is unnecessary: In this context, the word "to" is a preposition, which typically does not require capitalization unless it is the first word of a title or sentence.Therefore, the correct capitalization for the sentence is "I will be moving to China."
B. In the sentence "I will be moving to China," the capitalization is used correctly for the following reasons:Sentence beginning: The pronoun "I" is capitalized because it is at the beginning of the sentence. In English, the first word of a sentence is always capitalized.Proper noun: "China" is a proper noun referring to a specific country. Proper nouns, such as the names of countries, cities, or people, should be capitalized.Capitalizing "to" is unnecessary: In this context, the word "to" is a preposition, which typically does not require capitalization unless it is the first word of a title or sentence.Therefore, the correct capitalization for the sentence is "I will be moving to China."
C. The correct sentence is: "I will be moving to China."The capitalization is used correctly in this sentence for the following reasons:Sentence beginning: The pronoun "I" is capitalized because it is at the beginning of the sentence. In English, the first word of a sentence is always capitalized.Proper noun: "China" is a proper noun referring to a specific country. Proper nouns, such as the names of countries, cities, or people, should be capitalized.Capitalizing "Moving" is not necessary: The word "moving" is not a proper noun, and it is not the first word of the sentence or part of a title. Therefore, it does not require capitalization.Therefore, the correct capitalization for the sentence is "I will be moving to China."

Q5. Fill in with appropriate Article: To climb _ tree is not to climb _ mountain.

A. a/a✓
B. an/an
C. a/an
D. the/an
E. an/a

Explanation: a/a are the most appropriate articles to be used here.

Why the other options are wrong

B. This option suggests using the indefinite article "an" before both "tree" and "mountain." The indefinite article "an" is used before singular nouns that begin with a vowel sound. Similar to Option A, using the same article for both objects implies a general sense of climbing any tree and any mountain. It highlights the contrast between the actions without specifying any specific tree or mountain.
C. This option suggests using the indefinite article "a" before "tree" and the indefinite article "an" before "mountain." By using "a" before "tree," it implies climbing an unspecified or any tree. On the other hand, using "an" before "mountain" suggests climbing an unspecified or any mountain.
D. This option suggests using the definite article "the" before "tree" and the indefinite article "an" before "mountain." The definite article "the" is used when referring to a specific or known noun, while the indefinite article "an" is used when referring to a non-specific noun. By using "the" before "tree," it indicates a specific tree. Conversely, using "an" before "mountain" suggests climbing an unspecified or any mountain.
E. This option suggests using the indefinite article "an" before "tree" and the indefinite article "a" before "mountain." By using "an" before "tree," it implies climbing an unspecified or any tree. On the other hand, using "a" before "mountain" suggests climbing an unspecified or any mountain.

Q6. Error correction: I've lived in Barcelona since six years.

A. Has six years.
B. Been six years.
C. At six years.
D. Has been six years.
E. For six years.✓

Explanation: For is the correct word to be used here in place of since, thus option E is the correct answer. This option suggests replacing "since" with "for" and saying, "I've lived in Barcelona for six years." This is the most suitable and correct option. Using "for" indicates the duration of time (six years) that you have lived in Barcelona.

Why the other options are wrong

A. This option suggests replacing "since" with "has" and saying, "I've lived in Barcelona has six years." However, this change is not appropriate. "Has" does not convey the intended meaning and is not a suitable replacement for "since."
B. This option suggests replacing "since" with "been" and saying, "I've lived in Barcelona been six years." However, this change is not correct. "Been" does not fit grammatically in this context.
C. This option suggests replacing "since" with "at" and saying, "I've lived in Barcelona at six years." However, this change does not accurately convey the intended meaning. Using "at" in this context is not appropriate.
D. This option suggests replacing "since" with "has been" and saying, "I've lived in Barcelona has been six years." This option is incorrect because "has been" is not used correctly here.

Q7. Spot the correct spelling:

A. Coomitte
B. Commitee
C. Committey
D. Committee✓
E. Committeee

Explanation: "Committee" is the correct spelling for the word, indicating a group of people appointed or elected to perform a particular function or make decisions. Option D is the correct answer.

Why the other options are wrong

A. This option is spelled incorrectly. The correct spelling is "committee" with only one "o" in the middle.
B. This option is also spelled incorrectly. The correct spelling is "committee" with double "m" in the middle and double "t" at the end.
C. This option is spelled incorrectly. The correct spelling is "committee" with only one "t" at the end, not "t" followed by "ey".
E. This option is spelled incorrectly with an extra "e" at the end. The correct spelling is "committee" with only one "e" at the end.

Q8. To _, Anne was on time for her math class.

A. everybodys' surprise
B. everybody surprise
C. everybody's surprise✓
D. every bodys surprise
E. every-body surprise

Explanation: "Everybody’s surprise" is the correct option. Thus option C is the correct answer because the possessive form of "everybody" is correctly used with an apostrophe and an "s" ('s), indicating possession. It means that something was a surprise to everybody.

Why the other options are wrong

A. This option is incorrect. The possessive form of "everybody" should have an apostrophe and an "s" ('s) to indicate possession. The correct form would be "everybody's," as seen in Option C.
B. This option is incorrect. The word "everybody" is missing the possessive form or a possessive noun. It does not accurately convey the intended meaning of the sentence.
D. This option is incorrect. The word "every" and "bodys" should be written as one word, "everybody's." Additionally, the possessive form should have an apostrophe and an "s" ('s).
E. This option is incorrect. "Every-body" is not the correct form in this context. "Everybody" should be written as one word, and the possessive form with an apostrophe and an "s" ('s) should be used.

Q9. Find the error.

A. She showed us five different shades of blue paint.
B. She was approached, but she declined the offer.
C. There are seven floors in this building.
D. This is the best birthday party I have ever had.
E. When I go the museum, I wore comfortable shoes.✓

Explanation: Option E is the appropriate answer. It is the sentence containing an error. The correct form of the verb should be "went" instead of "go" to maintain the correct verb tense agreement. The corrected sentence would be, "When I went to the museum, I wore comfortable shoes."

Why the other options are wrong

A. This option does not contain any apparent errors. It is grammatically correct and makes sense in the given context.
B. This option does not contain any apparent errors. It is grammatically correct and makes sense in the given context.
C. This option does not contain any apparent errors. It is grammatically correct and makes sense in the given context.
D. This option does not contain any apparent errors. It is grammatically correct and makes sense in the given context.

Q10. Figure out the error: Scientist now hope that cloning can successfully be conducted in human beings in the near future.

A. can successfully be conducted in.
B. Scientist now hope that cloning.✓
C. in the near future.
D. conducted in human beings
E. No error.

Explanation: Option B Is the option containing the error. It should be corrected as "Scientist" should be changed to "scientists".

Why the other options are wrong

A. This option is grammatically correct.
C. This option is grammatically correct.
D. This option is grammatically correct.
E. This option is wrong as option B contains an error.

Q11. Fill in with the appropriate Article: _apple _ day keeps _doctor away.

A. the/a/a
B. an/a/an
C. an/the/the
D. a/a/the
E. an/a/the✓

Explanation: Articles an/a/the are the correct articles to be used here so option E is correct answer.

Why the other options are wrong

A. This option suggests using the definite article "the" before "apple," the indefinite article "a" before "day," and the indefinite article "a" before "doctor." It would result in "The apple a day keeps a doctor away." This option is grammatically correct and conveys the idea that any apple can have the mentioned effect on a person's health.
B. This option suggests using the indefinite article "an" before "apple," the indefinite article "a" before "day," and the indefinite article "an" before "doctor." It would result in "An apple a day keeps an doctor away." The incorrect usage of "an" before "doctor" should be corrected to "a" since "doctor" begins with a consonant sound.
C. This option suggests using the indefinite article "an" before "apple," the definite article "the" before "day," and the definite article "the" before "doctor." It would result in "An apple the day keeps the doctor away." The use of the definite articles "the" before "day" and "doctor" is not appropriate here. The sentence does not refer to specific or previously mentioned days or doctors.
D. This option suggests using the indefinite article "a" before "apple," the indefinite article "a" before "day," and the definite article "the" before "doctor." It would result in "A apple a day keeps the doctor away." The incorrect usage of "A" before "apple" should be corrected to "An" since "apple" begins with a vowel sound.

Q12. Fill in with the appropriate preposition:She climbed _ the ladder to paint the wall:

A. To
B. Up✓
C. Of
D. On
E. In

Explanation: The correct use of preposition is : She climbed "up"the ladder to paint the wall, thus option B is the correct answer.

Why the other options are wrong

A. The preposition "to" indicates movement or direction toward a specific point or goal. However, in this context, the correct preposition is "up" to convey the upward movement on the ladder.
C. The preposition "of" indicates possession or association, which is not suitable in this context.
D. The preposition "on" indicates contact or position upon a surface. However, the correct preposition to describe the climbing action is "up."
E. The preposition "in" indicates being inside or within something, which is not appropriate in this context.

Q13. Charles _, his father in the shop until school_.

A. is helping, starts✓
B. had help, started
C. helped, was starting
D. has helped, is starting
E. was helping, will start

Explanation: The correct sentence is: Charles _is helping_ his father in the shop until school_starts._ So option A is the correct answer.

Why the other options are wrong

B. This option suggests using the past perfect tense ("had help") to indicate a completed action in the past and the simple past tense ("started") to describe his father's action. It implies that Charles had already finished helping at some point in the past, and his father started working in the shop afterwards. This option conveys a sequence of past actions. This option is incorrect.
C. This option suggests using the simple past tense ("helped") to describe Charles' action and the past progressive tense ("was starting") to describe his father's action. It implies that Charles helped in the past, while his father was beginning or initiating his work in the shop. This option conveys a combination of completed and ongoing actions in the past. This option is incorrect.
D. This option suggests using the present perfect tense ("has helped") to describe Charles' action and the present progressive tense ("is starting") to describe his father's action. It implies that Charles has helped in the past up until now, and his father is currently beginning or initiating his work in the shop. This option conveys a connection between past actions and current actions. This option is incorrect.
E. This option suggests using the past progressive tense ("was helping") to describe Charles' action and the simple future tense ("will start") to describe his father's action. It implies that Charles was helping in the past, while his father will begin or initiate his work in the shop in the future. This option conveys a combination of past and future actions. This option is incorrect.

Q14. Fill in with a suitable Verb: The teacher_ completed this chapter.

A. Have
B. Is
C. Are
D. Has✓
E. They

Explanation: The correct use of verb is: The teacher_has_ completed this chapter. Has is use because teacher is a singular person. So option D is the correct option.

Why the other options are wrong

A. This option suggests using the verb "have" in the present tense. However, in the sentence, "The teacher" is the subject, and the verb needs to agree with it. "Have" is not the correct form for the singular subject "teacher" in this sentence.
B. This option suggests using the verb "is" in the present tense. It agrees with the singular subject "teacher" and correctly indicates that the action of completing the chapter is happening in the present.
C. This option suggests using the verb "are" in the present tense. However, "are" is the plural form of the verb, and it does not agree with the singular subject "teacher." Therefore, this option is not suitable in this context.
E. This option suggests using the pronoun "they" instead of a verb. While "they" is a subject pronoun, it does not serve as a verb to complete the sentence.

Q15. One must consider about any matter before _ it.

A. Decided
B. Decides
C. Decide
D. Was decide
E. Deciding✓

Explanation: The correct sentence is: One must consider about any matter before deciding it. So option E is the correct option.

Why the other options are wrong

A. This option suggests using the past tense verb "decided." However, the sentence requires a verb form that indicates a general or habitual action. "Decided" is not appropriate in this context.
B. This option suggests using the present tense verb "decides." However, the sentence requires a verb form that is consistent with the phrase "before _ it," indicating an action that precedes another action. The present tense "decides" does not convey the correct meaning.
C. This option suggests using the base form of the verb "decide.The correct form would be "before deciding it."
D. This option contains an error in verb tense agreement. The subject "one" requires the third-person singular form of the verb, which should be "was decided" instead of "was decide." However, this option still does not accurately convey the intended meaning of the sentence.

Q16. Read the passage to answer questions:But man is not destined to vanish. He can be killed, but he cannot be destroyed because his soul is deathless, and his spirit is irrepressible. Therefore, though the situation seems park in the context of the confrontation between the superpowers, the silver lining is provided by an amazing phenomenon that the very nations which have spent incalculable resources and energy for the production of deadly weapons and desperately trying to find out how they might never be used. They threaten each other, intimidate each other and go to the brink, but before the total hour arrives, they withdraw from the brink.A suitable title for the above passage is:

A. Cost of living
B. Man's desire to survive inhibits use of deadly weapons✓
C. Threats and intimidation between superpowers
D. Destruction of mankind is inevitable

Explanation: The mosy suitable title among all the options for the above passage is: "Man's desire to survive inhibits use of deadly weapons". So option B is the correct answer.

Why the other options are wrong

A. This option does not accurately capture the main idea of the passage. The passage primarily discusses the resilience of mankind and the restraint in using deadly weapons rather than the cost of living.
C. This option focuses on the confrontations between superpowers mentioned in the passage. While this is mentioned in the passage, it does not capture the overarching theme or main idea of the passage, which is about the resilience and restraint of mankind in using deadly weapons.
D. This option does not accurately reflect the main idea of the passage. The passage conveys the opposite notion, emphasizing that while man can be killed, he cannot be destroyed due to the deathlessness of the soul and the irrepressible spirit. It focuses on the resilience and survival of mankind.

Q17. Read the following passage to answer the given question:But man is not destined to vanish. He can be killed, but he cannot be destroyed because his soul is deathless, and his spirit is irrepressible. Therefore, though the situation seems park in the context of the confrontation between the superpowers, the silver lining is provided by amazing phenomenon that the very nations which have spent incalculable resources and energy for the production of deadly weapons and desperately trying to find out how they might never be used. They threaten each other, intimidate each other and go to the brink, but before the total hour arrives, they withdraw from the brink.The main point from the author's view is that:

A. Man has come here to live
B. Man's soul and spirit cannot be destroyed by super powers
C. Man's destiny is not fully clear or visible
D. Human society will survive despite the serious threat of total annihilation✓

Explanation: The main point from the author's view is that human society will survive despite the serious threat of total annihilation. So option D is the correct option.

Why the other options are wrong

A. This option does not accurately capture the main point from the author's view as presented in the passage. The passage does not specifically focus on the purpose or reason for man's existence, and it is not the primary point the author is trying to convey.
B. This option does not accurately capture the main point from the author's view as presented in the passage. While the passage mentions the indestructibility of man's soul and spirit, it is not the main focus or central point being emphasized.
C. This option does not accurately capture the main point from the author's view as presented in the passage. While the passage mentions that man's destiny is not fully clear or visible, it is not the primary point or main focus of the author's perspective.

Q18. Read the following passage to answer the given question:But man is not destined to vanish. He can be killed, but he cannot be destroyed because his soul is deathless, and his spirit is irrepressible. Therefore, though the situation seems park in the context of the confrontation between the superpowers, the silver lining is provided by an amazing phenomenon that the very nations which have spent incalculable resources and energy for the production of deadly weapons and desperately trying to find out how they might never be used. They threaten each other, intimidate each other and go to the brink, but before the total hour arrives, they withdraw from the brink. 'Irrepressible' in the second line means:

A. Harmful
B. Incompatible
C. Strong
D. Unrestrainable✓

Explanation: 'Irrepressible' in the second line means Unrestrainable. So Option D is the correct answer according to context.

Why the other options are wrong

A. This option does not accurately define the term "irrepressible." In the given context, "irrepressible" does not imply something harmful but rather suggests the inability to be suppressed or restrained.
B. This option does not accurately define the term "irrepressible." "Incompatible" refers to things that are not able to exist or work together harmoniously. It does not convey the meaning of being unable to be suppressed or restrained.
C. This option does not accurately define the term "irrepressible." While "strong" can imply resilience or resistance, it does not capture the full meaning of "irrepressible," which means unable to be suppressed or restrained.

Q19. Cell becomes dead due to the deposition of:

A. Cellulose
B. Cutin
C. Chitin
D. Lignin✓
E. Hemicelluloses

Explanation: Cells become dead due to the deposition of lignin in them. Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Thus Option D is the correct answer.

Why the other options are wrong

A. Cellulose is a complex carbohydrate and a major component of plant cell walls. It provides structural support to plant cells but does not directly cause cell death. Cellulose is not typically associated with the deposition that leads to cell death.
B. Cutin is a waxy substance that forms a protective layer on the outer surface of plant tissues, such as leaves and stems. It helps reduce water loss and protects against pathogens but does not cause cell death.
C. Chitin is a tough, structural polysaccharide found in the cell walls of fungi and the exoskeletons of arthropods. It is not typically associated with cell death in plant cells.
E. Hemicelluloses are a group of complex carbohydrates found in plant cell walls. They play a role in the cell wall structure and contribute to the binding of cellulose fibers. Excessive deposition of hemicelluloses is not typically associated with cell death.

Q20. Rabies is caused by:

A. Paramyxovirus
B. Rhinovirus
C. Arbovirus
D. Rhabdovirus✓
E. Poliovirus

Explanation: Rabies is a viral disease that affects the central nervous system and is caused by the Rhabdovirus. The specific virus responsible for rabies is called the Rabies lyssavirus, which belongs to the family Rhabdoviridae.

Why the other options are wrong

A. Paramyxoviruses are a family of viruses that can cause various diseases in humans and animals. However, rabies is not caused by a paramyxovirus.
B. Rhinoviruses are responsible for causing the common cold in humans. They are not associated with the transmission or cause of rabies. Therefore, Option B is not the correct answer.
C. Arboviruses are a group of viruses that are transmitted to humans through arthropod vectors, such as mosquitoes or ticks. While some arboviruses can cause diseases like dengue fever or Zika virus, rabies is not caused by an arbovirus. Thus, Option C is not the correct answer.
E. Poliovirus is responsible for causing poliomyelitis, also known as polio, which is a viral infection that affects the nervous system. However, poliovirus is not the cause of rabies. Therefore, Option E is not the correct answer.

Q21. In AIDS, "D" stands for:

A. Different
B. Difficult
C. Deficiency✓
D. Degenerate

Explanation: The abbreviation of AIDS is Acquired Immune Deficiency Syndrome, so D in AIDS stands for deficiency. Thus option C is the correct option.

Why the other options are wrong

A. D in AIDS stands for “deficiency. Because in the condition. The body is deficient in fighting off diseases and infection.
B. The “D” in AIDS stands for deficiency because the disease weakens the immune system to the point where it can’t protect the body the way it should. As HIV damages the immune cells, the body becomes less able to fight off infections and illnesses, which is why the term immune deficiency is used.
D. The “D” in AIDS means deficiency because HIV weakens the immune system, leaving the body unable to fight infections effectively.

Q22. It is a loop or set of responses shown by the effectors that weakens the effect of the initial stimuli:

A. Negative feed back✓
B. Neutral condition
C. Positive feed back
D. Static state
E. Thermal state

Explanation: Negative feedback is a regulatory mechanism that works to counteract or reduce the effects of a stimulus, restoring the system to its original state or set point. In a negative feedback loop, the response by the effectors weakens or opposes the initial stimulus. So option A is the correct answer.

Why the other options are wrong

B. "Neutral condition" does not accurately describe the concept described in the question. A neutral condition typically refers to a state where no particular response or effect is observed.
C. Positive feedback refers to a regulatory mechanism in which the effectors respond to the initial stimulus by amplifying or enhancing the intensity of the stimulus. This leads to a cascading effect that further strengthens the response and moves the system away from its initial state.
D. "Static state" does not accurately describe the concept described in the question. A static state typically refers to a state of equilibrium or stability where there is no change or movement.
E. "Thermal state" does not accurately describe the concept described in the question. The term "thermal" relates to heat or temperature and is not directly related to the feedback mechanism described in the question.

Q23. Stage where crossing over occurs in meiosis:

A. Leptotene
B. Zygotene
C. Pachytene✓
D. Diplotene

Explanation: Pachytene is where homologous non-sister chromatids exchange segments.

Why the other options are wrong

A. During leptotene, chromosomes begin to condense and become visible, but no crossing over has occurred yet.
B. In zygotene, homologous chromosomes start to pair up and align, but crossing over does not happen at this stage.
D. In diplotene, the homologous chromosomes begin to separate, and while some recombination may still be evident, crossing over has already occurred.

Q24. A co-enzyme constitute about a certain % of the portion of the entire enzyme:

A. 5
B. 1✓
C. 2
D. 3
E. 4

Explanation: The exact percentage of coenzyme composition can vary depending on the specific enzyme and coenzyme involved, it is generally estimated that coenzymes constitute about 1% of the entire enzyme. This means that only a small fraction of the enzyme's overall structure is composed of coenzyme. So option B is the correct answer.

Why the other options are wrong

A. This is the incorrect percentage of co-enzyme in entire enzyme.
C. This is the incorrect percentage of co-enzyme in entire enzyme.
D. This is the incorrect percentage of co-enzyme in entire enzyme.
E. This is the incorrect percentage of co-enzyme in entire enzyme.

Q25. Each chain of DNA is formed by the union of many nucleotides by means of:

A. Double bond
B. Phosphodiester bonds✓
C. Covalent bond
D. Hydrogen bond
E. Single bond

Explanation: Each chain of DNA is formed by the union of many nucleotides through phosphodiester bonds. Phosphodiester bonds are covalent bonds. So option B is correct answer.

Why the other options are wrong

A. This type of bond is not present in chain of DNA by which nucleotides are united. This option is incorrect.
C. This type of bond is not present in chain of DNA by which nucleotides are united. This option is incorrect.
D. This type of bond is not present in chain of DNA by which nucleotides are united. This option is incorrect.
E. This type of bond is not present in chain of DNA by which nucleotides are united. This option is incorrect.

Q26. Mimosa pudica shows:

A. Thermonastic
B. Haptonastic
C. Nyctinastic
D. Seismonastic✓
E. Photonastic

Explanation: Mimosa pudica exhibits Seismonastic movements. Seismonastic movements, also known as thigmonastic movements, are rapid and reversible movements in response to touch or physical stimuli. Mimosa pudica, commonly known as the sensitive plant or touch-me-not, is well-known for its seismonastic response. When the leaves of Mimosa pudica are touched or disturbed, they rapidly fold and droop. So option D is the correct answer.

Why the other options are wrong

A. It is movement in response to temperature.It is not shown by Mimosa pudica.
B. It is the response to plant movement. It is not shown by Mimosa Pudica.
C. It is movement in response to light and darkness. It is not shown by Mimosa Pudica.
E. It is movement in response to light. It is not shown by Mimosa Pudica.

Q27. Mendel's for his research selected:

A. Edible-pea
B. Garden pea✓
C. Bean plant
D. Wild pea
E. Pea nut

Explanation: Mendel selected garden peas for his experiment as they were easier to get and do an experiment. So Option B s the correct answer.

Why the other options are wrong

A. This option is incorrect because it was not used by Mendel for his research.
C. This option is incorrect because it was not used by Mendel for his research.
D. This option is incorrect because it was not used by Mendel for his research.
E. This option is incorrect because it was not used by Mendel for his research.

Q28. This lipid is the most common, abundant richest source of energy in plant and animal body:

A. Phospholipid
B. Carotenoids
C. Terpenoids
D. Terpenes
E. Acylglycerols✓

Explanation: Acylglycerols, also known as triglycerides or triacylglycerols, are the most common and abundant form of lipid storage in both plants and animals. They serve as a concentrated and efficient energy source. Acylglycerols comprise a glycerol molecule attached to three fatty acid chains through ester linkages.

Why the other options are wrong

A. They have essential functions, including the provision of membranes required for protein synthesis and export, cholesterol homeostasis, and triacylglycerol storage and secretion. This isn't the correct type of lipid, which is the richest, most common source of energy in plants and animal bodies.
B. Carotenoids are the most widely distributed pigments in nature and are present in photosynthetic bacteria, some species of archaea and fungi, algae, plants, and animals. This isn't the correct type of lipid, which is the richest, most common source of energy in plants and animal bodies.
C. Terpenoids have been found to be useful in the prevention and therapy of several diseases, including cancer. This isn't the correct type of lipid which is the richest, common source of energy in plants and animal bodies.
D. They're responsible for the aromas, flavours, and even colours associated with various types of vegetation. So this isn't the correct type of lipid, which is the richest, most common source of energy in plants and animal bodies.

Q29. The organs perform same functions in different groups of organism but are different in this internal structure called as:

A. Bysmmetry
B. Analogus organs✓
C. Homologus organs
D. Radial symmetry
E. Asymmetry

Explanation: Analogous organs are organs that have similar functions but different structures and evolutionary origins. They are not derived from a common ancestor. These organs have independently evolved to perform similar functions in different groups of organisms. For example, the wings of birds and the wings of insects serve the same function of flying, but their structures and developmental origins are different.

Why the other options are wrong

A. There is no commonly recognized term or concept in biology called "bysymmetry." It does not relate to the internal structure of organs performing the same functions.
C. Homologous organs are organs that have a similar structure and origin but may have different functions in different organisms. They indicate evolutionary relatedness and common ancestry. For example, the forelimbs of mammals (including humans) and the wings of birds have different functions (walking and flying, respectively) but share a similar underlying structure.
D. Radial symmetry refers to a body plan in which body parts are arranged around a central axis, resulting in multiple planes of symmetry. It is not directly related to the internal structure of organs performing the same functions.
E. In biology, asymmetry refers to the absence or lack of symmetry in an organism or a structure within an organism. Symmetry refers to a balanced arrangement of parts around an axis or a centre, while asymmetry indicates a lack of balance or symmetry.

Q30. The hard parts of the seeds is primarily due to the presence of:

A. Collenchyma
B. Sclerenchyma
C. Sclereids✓
D. Fibres
E. Parenchyma

Explanation: Sclerieds, also known as stone cells, are specialized sclerenchyma cells found in some plant tissues. They are particularly abundant in fruits, giving them a gritty or stony texture. They function in giving hardness to seeds. They are shorter and have more varied shapes than sclerenchyma fibers, and are found in various parts of plants like seed coats, fruit pulp, and nutshells.

Why the other options are wrong

A. Collenchyma cells are living plant cells that provide flexible support to growing plant parts. They do not function in giving hardness to seed.
B. Sclerenchyma cells are specialized plant cells that provide mechanical support and strength to various plant structures. They have thick, lignified cell walls that make them rigid and resistant to degradation.
D. Fibres, such as the ones found in the phloem tissue of plants, are elongated and thick-walled cells that provide support and strength. They do not function in giving hardness to seed.
E. Parenchyma cells are the most common type of plant cell, with thin and flexible cell walls. They do not function in giving hardness to seed.

Q31. Virus is a latin word meaning:

A. Sweet
B. Sour
C. Poison✓
D. Toxic
E. Acidic

Explanation: In Latin, virus means poison/ slimy liquid. It is a substance which is capable of infecting others.

Why the other options are wrong

A. In Latin, virus originally meant “poison” or “venom.”The word was used for harmful fluids long before microbes were known.Scientists later adopted it because early viral infections seemed like an invisible poison.
B. In Latin, virus referred to a poisonous or venomous substance.People used the term for dangerous fluids before microbes were discovered.Researchers later applied it to viral infections because they acted like an unseen toxin.
D. Not all viruses are toxic. Some can be toxic by nature. But they are host specific.
E. They do have nucleic acid in the form of either DNA or RNA. But they are not necessarily acidic.

Q32. In the heart, the thick-walled chambers are located at the:

A. Apex✓
B. Lower side
C. Lateral side
D. Dorsal side
E. Ventral side

Explanation: Thick-walled chambers (ventricles) are located at the apex of the heart. So option A is the correct answer.

Why the other options are wrong

B. This is not the correct location of thick walled chambers of heart.
C. This is not the correct location of thick walled chambers of heart.
D. This is not the correct location of thick walled chambers of heart.
E. This is not the correct location of thick walled chambers of heart.

Q33. Extremely thin appendages helping during conjugation in bacteria:

A. Pili✓
B. Membrane
C. Flagella
D. Tentacle
E. Cilia

Explanation: The thin appendages that help bacteria in conjugation are pili. So option A is the correct answer.

Why the other options are wrong

B. A bacterial membrane (cell membrane) is the inner lipid bilayer of the bacterium that controls transport of materials in and out of the cell.Although it is essential for survival, it does not form external appendages and does not play any role in conjugation.Hence, this option is incorrect.
C. Flagella are long, whip-like structures used by bacteria for motility (movement).They rotate like a propeller to help bacteria swim toward nutrients or away from harmful substances.They have no involvement in DNA transfer or conjugation, so this option is incorrect.
D. Tentacles are not found in bacteria at all.The term “tentacle” is used for animals like jellyfish or octopus, not microorganisms.Therefore, this option is completely incorrect.
E. Cilia are short, hair-like organelles found in some eukaryotic cells (like human respiratory epithelium), not bacteria.Bacteria do not possess cilia, and cilia have no role in conjugation.Thus, this option is incorrect.

Q34. Colourless plastid is called:

A. Leucoplast✓
B. Chromoplast
C. Cyanoplast
D. Chloroplast

Explanation: Leucoplasts are the colourless plastids present in underground parts of plants, thus, option A is correct.

Why the other options are wrong

B. Chromoplasts are pigmented plastids that provide red, orange, or yellow colors to flowers, fruits, and other plant parts, so they are not colorless like leucoplasts, making this option incorrect.
C. This plastid is a cyanelle, a type of chloroplast containing chlorophyll, so it is green and photosynthetic rather than colorless, making this option incorrect.
D. Chloroplasts are green plastids containing chlorophyll that carry out photosynthesis, so they are not colorless like leucoplasts, making this option incorrect.

Q35. Evolution is the transformation of the form & mode of existence of an organism in such manner that the descendants differ from their ancestor, according to:

A. Weismann
B. Lamarck
C. Charles Darwin✓
D. Zimmermann

Explanation: The theory of evolution was developed by Charles Darwin and is based on the principles of natural selection and gradual changes over long periods of time. According to the theory, populations of organisms undergo genetic variations, and those variations that confer advantageous traits are more likely to be passed on to future generations. Over time, these accumulated changes can lead to the emergence of new species or the extinction of existing ones.

Why the other options are wrong

A. This statement is not according to Weismann. According to his theory, germplasm, which is independent of all other cells of the body (somatoplasm), is the essential element of germ cells (eggs and sperm) and is the hereditary material that is passed from generation to generation. Weismann first proposed this theory in 1883.
B. This statement is not according to Lamarck. According to Lamarck, organisms alter their behaviour in response to environmental change. Their changed behaviour, in turn, modified their organs, and their offspring inherited those "improved" structures.
D. In its general form, the telome theory proposes that by combining and modifying simple multicellular telomes through one or more developmental processes, it is possible to explain all extant and extinct plant morphologies.

Q36. The uterus opens to the vagina by a narrow opening bounded by a muscular sphincter at its bottom known as:

A. Urinary bladder
B. Cervix✓
C. Oviduct
D. Labia
E. Vagina

Explanation: The cervix is a vital part of the female reproductive system. It is a cylindrical-shaped structure that forms the lower part of the uterus (womb) and connects it to the vagina. So the correct option is B.

Why the other options are wrong

A. The urinary bladder is a hollow, muscular organ located in the pelvic area of the human body. Its primary function is to store urine produced by the kidneys before it is eliminated from the body through the process of urination.
C. The oviduct, also known as the fallopian tube or uterine tube, is a pair of slender tubes in the female reproductive system.
D. The labia, are external folds of skin located in the genital area of females.
E. The vagina is a muscular canal located in the female reproductive system. It is an essential part of the female genitalia.

Q37. The skeleton of marine shelled sarcodians gives clues to the possible deposit of:

A. Potassium
B. Magnesium
C. Petroleum
D. Chromium
E. Calcium✓

Explanation: The skeletons of marine shelled sarcodians, including foraminifera and radiolarians, are often composed of calcium carbonate. Calcium carbonate is a mineral that forms the basis of their hard shells, and when these organisms die, their shells can accumulate on the ocean floor, contributing to the formation of calcium carbonate-rich sediments.

Why the other options are wrong

A. The shell of Sarcodians is not made up of Potassium deposits.
B. The shell of Sarcodians is not made up of Magnesium deposits.
C. The shell of Sarcodians is not made up of petroleum deposits.
D. The shell of Sarcodians is not made up of Chromium deposits.

Q38. The spinal cord comes out from the cranium through an opening known as:

A. Foramen magnum✓
B. Lumen
C. Ganglion
D. Acetubulum
E. Glanoid cavity

Explanation: The foramen magnum is a large opening at the base of the skull through which the spinal cord passes. It connects the cranial cavity with the vertebral canal. The spinal cord, which is an important part of the central nervous system, extends from the brain and travels through the foramen magnum to transmit nerve signals between the brain and the rest of the body. So option A is the correct answer.

Why the other options are wrong

B. The term "lumen" refers to the central opening or space within a tubular structure, such as a blood vessel or a hollow organ. While the spinal cord is a tubular structure, it does not come out from the cranium through a lumen. Therefore, Option B is not the correct answer.
C. A ganglion is a cluster of nerve cell bodies located outside the central nervous system. It is not directly related to the opening through which the spinal cord exits the cranium. Therefore, Option C is not the correct answer.
D. The acetabulum is a part of the hip bone, specifically the socket of the hip joint. It is not related to the opening through which the spinal cord exits the cranium. Therefore, Option D is not the correct answer.
E. The glenoid cavity is part of the shoulder joint and is found in the scapula (shoulder blade). It is not related to the opening through which the spinal cord exits the cranium. Therefore, Option E is not the correct answer.

Q39. Hepatitis is caused by:

A. Protozoans
B. Algae
C. Bacteria
D. Fungi
E. Virus✓

Explanation: Hepatitis is an inflammation of the liver, and it can be caused by several factors, including viral infections. The most common types of hepatitis are caused by viruses, specifically hepatitis A, hepatitis B, hepatitis C, hepatitis D, and hepatitis E viruses. Therefore the correct option is E.

Why the other options are wrong

A. It is not a cause of viral hepatitis because it is not a virus.
B. Hepatitis is mainly viral, and in some cases it can be due to alcohol, drugs, toxins, or autoimmune disease.
C. No, bachteria do not cause hepatitis. Hepatitis is mainly viral, and in some cases it can be due to alcohol, drugs, toxins, or autoimmune disease.
D. No, fungi do not cause hepatitis. Hepatitis is mainly viral, and in some cases it can be due to alcohol, drugs, toxins, or autoimmune disease—but not fungi.

Q40. Syphilis is caused by a bacteria called as:

A. Bacilli
B. Trichomonas
C. Neisseria gonorrhea
D. Genital herpes
E. Treponema palladium✓

Explanation: The correct answer is Option E. Syphilis is caused by a bacterium called Treponema pallidum. It is a spirochete bacterium that is transmitted through sexual contact or from mother to child during pregnancy. Treponema pallidum is the specific bacteria responsible for causing syphilis.

Why the other options are wrong

A. Bacilli is a plural term used to refer to rod-shaped bacteria. While there are bacteria that have a rod-like shape, syphilis is not caused by bacilli. Therefore, Option A is not the correct answer.
B. Trichomonas is a single-celled parasite that can cause an infection called trichomoniasis. However, trichomonas is not the bacteria that causes syphilis. Therefore, Option B is not the correct answer.
C. Neisseria gonorrhea is a bacterium that causes the sexually transmitted infection gonorrhea. While both syphilis and gonorrhea are sexually transmitted infections, Neisseria gonorrhea is not the bacteria that causes syphilis. Therefore, Option C is not the correct answer.
D. Genital herpes is a viral infection caused by the herpes simplex virus. It is not caused by bacteria. Therefore, Option D is not the correct answer.

Q41. The presence of remnants of the pelvic girdle in whale and snake, although they never have legs, shows evidence of:

A. Biochemical evidence
B. Paleontology
C. Vestigial organs✓
D. Embryology
E. Taxonomy

Explanation: The correct answer is Option C. The presence of remnants of the pelvic girdle in whales and snakes, despite not having legs, is an example of vestigial organs. Vestigial organs are structures in an organism that have reduced or no function in the current form but have a significant function in the ancestors. These remnants provide evidence of evolutionary history and can be observed in various species.

Why the other options are wrong

A. Biochemical evidence refers to the study of the chemical processes and substances within living organisms. It does not directly relate to the presence of remnants of the pelvic girdle in whales and snakes. Therefore, Option A is not the correct answer.
B. Paleontology is the study of fossils to understand the history of life on Earth. The presence of remnants of the pelvic girdle in whales and snakes, despite the absence of legs, is a piece of evidence that can be examined through paleontological studies. It provides insights into the evolutionary history and changes in body structures over time. Therefore, Option B is a relevant answer.
D. Embryology is the study of the development of embryos. While embryology can provide insights into the development of body structures, it is not directly related to the presence of remnants of the pelvic girdle in whales and snakes. Therefore, Option D is not the correct answer.
E. Taxonomy is the science of the classification and categorization of organisms. While taxonomy can provide information about the relationships between different species, it does not directly relate to the presence of remnants of the pelvic girdle in whales and snakes. Therefore, Option E is not the correct answer.

Q42. Photosynthetic bacteria liberate:

A. CO2
B. H2S
C. S✓
D. H
E. O

Explanation: In sulfur photosynthetic bacteria, the substance that donates hydrogen is hydrogen sulfide (H2S) and not water. Therefore there is no liberation of molecular oxygen, but there is a production of molecular sulfur (S2). (Oxygen and sulfur have same number of valence electrons.)

Why the other options are wrong

A. Photosynthetic bacteria do not liberate carbon dioxide. In fact, CO₂ is one of the raw materials they consume during photosynthesis. Just as plants take in carbon dioxide to synthesize carbohydrates, photosynthetic bacteria also use CO₂ during their metabolic processes. Since CO₂ is a reactant, not a product, it is not released by these bacteria. Therefore, this option is incorrect.
B. Hydrogen sulfide (H₂S) is not released by photosynthetic bacteria. Instead, in sulfur photosynthetic bacteria (such as purple sulfur bacteria and green sulfur bacteria), H₂S acts as the hydrogen donor, much like water acts in plant photosynthesis. These bacteria oxidize H₂S rather than releasing it. During this process, hydrogen from H₂S is used for carbohydrate formation, and sulfur is produced as a by-product. Thus, H₂S is consumed, not liberated, making this option incorrect.
D. Photosynthetic bacteria do not release free hydrogen atoms or hydrogen gas during their photosynthetic reactions. Although hydrogen atoms from H₂S are used internally to help synthesize organic molecules, they are not released as a waste product. This makes hydrogen an incorrect answer in the context of what photosynthetic bacteria liberate during photosynthesis.
E. Photosynthetic bacteria that use H₂S instead of water do not release oxygen. Oxygen is only released by organisms that perform oxygenic photosynthesis, such as plants, algae, and cyanobacteria, where water is split to produce O₂. In sulfur photosynthetic bacteria, water is not the hydrogen donor—H₂S is—so no oxygen is formed. Therefore, oxygen is not a product and this option is incorrect.

Q43. Plasma membrane is:

A. Permeable
B. Selective permeable✓
C. Impermeable
D. Sub permeable
E. Non permeable

Explanation: Plasma membrane does not allow all the substances to pass through it hence it is selectively permeable. So option B is the correct answer.

Why the other options are wrong

A. The plasma membrane is selectively permeable, meaning it allows only certain substances to pass while blocking others. Small nonpolar molecules like oxygen and carbon dioxide can diffuse freely, but ions, large polar molecules, and most nutrients require specific transport proteins. This selective control maintains the cell’s internal environment, supports metabolism, and protects against harmful substances.
C. Since the plasma membrane allows certain molecules like oxygen, carbon dioxide, and water to pass, it cannot be completely impermeable. Its selective permeability ensures essential nutrients enter, waste exits, and harmful substances are blocked, maintaining cellular balance. .
D. The plasma membrane is not permeable to all substances; it only allows certain molecules like small gases and water to pass freely. Larger molecules, ions, and most polar substances require specific transport proteins. This selective permeability protects the cell and regulates its internal environment.
E. The plasma membrane is not completely non-permeable because some substances, like oxygen, carbon dioxide, and water, can cross freely. Its selective permeability allows essential molecules in and waste out, maintaining the cell’s internal balance.

Q44. Water in the most of compound in living organism its amount varies from:

A. 30% to 60%
B. 50% to 60%
C. 10% to 20%
D. 70% to 90%✓
E. 40% to 50%

Explanation: Water makes up a big part of living body, thus in living being it varies from 70%-90%. Therefore option D is correct answer.

Why the other options are wrong

A. This is not the correct amount of water present in living organisms.
B. This is not the correct amount of water present in living organisms. Organisms generally consist of about 70% to 90% water, with the exact level depending on the species and tissue. This high water content is crucial for basic cellular functions and chemical reactions.
C. This is not the correct amount of water present in living organisms. Most living organisms are made up of roughly 70% to 90% water, though the exact amount varies with the species and the type of tissue. This large water fraction helps keep cells stable and allows vital biochemical processes to take place.
E. This is not the correct amount of water present in living organisms. Organisms generally consist of about 70% to 90% water, with the exact level depending on the species and tissue. This high water content is crucial for basic cellular functions and chemical reactions.

Q45. The phase in which bicuspid and tricuspid valves open & semilunar valve close which produce 2nd heart sound (dub or dup). This the phase is known as:

A. Atrial diastole
B. Ventricular diastole✓
C. Ventricular systole
D. Contraction of heart
E. Systole

Explanation: The phase in which the bicuspid and tricuspid valves open & semilunar valve close produces 2nd heart sound (dub or dup). This phase is known as ventricular diastole. So option B is the correct answer.

Why the other options are wrong

A. Atrial diastole refers to the phase of the cardiac cycle when the atria are relaxed and filling with blood. It is not directly related to the opening of the bicuspid and tricuspid valves or the closure of the semilunar valve, which is responsible for producing the second heart sound. Therefore, Option A is not the correct answer.
C. Ventricular systole refers to the phase of the cardiac cycle when the ventricles contract and pump blood out of the heart. During ventricular systole, the bicuspid and tricuspid valves are closed to prevent the backflow of blood into the atria, and the semilunar valves are open, allowing blood to be ejected from the ventricles into the aorta and pulmonary arteries. While ventricular systole is an important phase of the cardiac cycle, it is not the phase responsible for producing the second heart sound. Therefore, Option C is not the correct answer.
D. "Contraction of heart" is a general term that refers to the overall action of the heart muscles contracting. While the contraction of the heart is involved in both atrial and ventricular systole, it does not specifically describe the phase where the bicuspid and tricuspid valves open and the semilunar valve closes to produce the second heart sound. Therefore, Option D is not the correct answer.
E. Systole is a general term that refers to the phase of the cardiac cycle when the heart muscle contracts and blood is pumped out. It can be used to describe both atrial and ventricular systole. However, in the context of the given question, Option E does not specifically indicate the phase where the bicuspid and tricuspid valves open and the semilunar valve closes to produce the second heart sound. Therefore, Option E is not the correct answer.

Q46. Phenotypic ratio of law of independent assortment of genes:

A. 9:7
B. 13:3
C. 9:3:3:1✓
D. 15:1
E. 12:3:1

Explanation: The phenotypic ratio of the law of independent assortment of genes is 9:3:3:1. Therefore, the correct option is C.

Why the other options are wrong

A. This is not the correct phenotypic ratio of law of independent assortment of genes.
B. This is not the correct phenotypic ratio of law of independent assortment of genes.
D. This is not the correct phenotypic ratio of law of independent assortment of genes.
E. This is not the correct phenotypic ratio of law of independent assortment of genes.

Q47. Triose and glycerol is used in the synthesis of:

A. Carbohydrate
B. Protein
C. Lipid✓
D. Fatty acid
E. Phospholipid

Explanation: Triose and glycerol are both utilized in the synthesis of lipids. Glycerol serves as the backbone for triglycerides and phospholipids, which are key types of lipids. Triose, being a three-carbon sugar, is involved in various metabolic pathways that can lead to lipid synthesis. The correct answer is option C, Lipid, since it encompasses both glycerol and fatty acids as building blocks. Option A (Carbohydrate) is incorrect because carbohydrates are formed from sugars, not directly from glycerol. Option B (Protein) is incorrect as proteins are made from amino acids, not from glycerol or triose. Option D (Fatty acid) is misleading as it specifies a type of lipid rather than the broader category. Option E (Phospholipid) is incorrect because while phospholipids are derived from glycerol, the question aims for the broader category, which is lipids.

Why the other options are wrong

A. Triose and glycerol do not play a direct role in the synthesis of carbohydrates. Carbohydrates are primarily formed from monosaccharides like glucose.
B. Triose and glycerol are not involved in the synthesis of proteins, which are made up of amino acids linked by peptide bonds.
D. While fatty acids are indeed synthesized from glycerol, the question specifically asks for the broader category that includes them, which is lipids.
E. Triose and glycerol are not directly used in the synthesis of phospholipids, which are composed of glycerol, fatty acids, and phosphate groups.

Q48. They are inhibitors of key enzymes in the nervous system:

A. Calcium and Potassium
B. Substrate and activators
C. Hexokinase and glucose
D. Magnesium and manganese
E. Pesticides DDT and parathione✓

Explanation: The correct answer is E Pesticides DDT and parathione. Pesticides such as DDT (dichlorodiphenyltrichloroethane) and parathion are known to be inhibitors of key enzymes in the nervous system. DDT was commonly used as an insecticide, while parathion is an organophosphate insecticide. Both of these pesticides can affect the activity of enzymes in the nervous system, leading to adverse effects on the functioning of nerve cells.

Why the other options are wrong

A. Calcium and potassium are essential ions in the body, but they are not inhibitors of key enzymes in the nervous system. Instead, they play crucial roles in various cellular processes, including nerve signaling and muscle contraction. Therefore, Option A is not the correct answer.
B. Substrate and activators are not inhibitors of key enzymes in the nervous system. Substrates are the molecules that enzymes act upon, and activators are molecules that enhance the activity of enzymes. They do not inhibit the function of enzymes. Therefore, Option B is not the correct answer.
C. Hexokinase is an enzyme that plays a role in glucose metabolism, particularly in the first step of glucose utilization in cells. Glucose, on the other hand, is a sugar molecule that serves as a fuel source for cellular energy production. Neither hexokinase nor glucose are inhibitors of key enzymes in the nervous system. Therefore, Option C is not the correct answer.
D. Magnesium and manganese are essential minerals in the body, but they are not typically considered inhibitors of key enzymes in the nervous system. They often act as cofactors or activators for enzymes, assisting in their proper function. Therefore, Option D is not the correct answer.

Q49. The plant hormone associated with apical dominance is:

A. Auxin✓
B. Gibberellin
C. Cytokinin
D. Ethene
E. Abscisic acid

Explanation: The correct answer is A Auxin. Apical dominance is a phenomenon in plants where the growth and development of the main apical bud at the tip of a stem inhibits the growth of lateral buds further down the stem. Auxin is the plant hormone primarily associated with apical dominance.

Why the other options are wrong

B. Gibberellins are plant hormones that are primarily involved in promoting stem elongation, seed germination, and flowering. While gibberellins have various effects on plant growth and development, they are not specifically associated with apical dominance. Therefore, Option B is not the correct answer.
C. Cytokinins are plant hormones that are involved in cell division and growth, as well as the regulation of various physiological processes. Cytokinins do not have a direct association with apical dominance. Instead, they often work in conjunction with auxin to regulate plant growth and development. Therefore, Option C is not the correct answer.
D. Ethene, also known as ethylene, is a plant hormone involved in various physiological processes, including fruit ripening and senescence. While ethene does influence some aspects of plant growth and development, it is not specifically associated with apical dominance. Therefore, Option D is not the correct answer.
E. Abscisic acid is a plant hormone that primarily regulates responses to environmental stresses, such as drought, cold, and salinity. While it has many important roles in plant physiology, abscisic acid is not directly associated with apical dominance. Therefore, Option E is not the correct answer.

Q50. Bolus enters the esophagus not the trachea due to the presence of:

A. Roof palate
B. Mouth
C. Epiglottis✓
D. Buccal cavity
E. Tongue

Explanation: The bolus, which is a mass of chewed food, enters the oesophagus and not the trachea (windpipe) primarily due to the presence of the epiglottis. The epiglottis is a flap-like structure present in the mouth. Therefore, option C is the correct answer.

Why the other options are wrong

A. The roof palate, or the hard palate, is the bony structure located at the roof of the mouth. While it does play a role in separating the oral cavity from the nasal cavity, it is not directly involved in preventing the entry of a bolus into the trachea. Therefore, Option A is not the correct answer.
B. The mouth, or oral cavity, is where food is initially taken in and chewed into a bolus. While the mouth is involved in the process of swallowing, it does not directly prevent the entry of the bolus into the trachea. Therefore, Option B is not the correct answer.
D. The buccal cavity refers to the oral cavity, specifically the space between the cheeks and the gums. While the buccal cavity is involved in the process of chewing and swallowing, it is not directly responsible for preventing the entry of the bolus into the trachea. Therefore, Option D is not the correct answer.
E. The tongue is a muscular organ located in the mouth that aids in the manipulation of food during chewing and swallowing. While the tongue plays a role in guiding the bolus to the back of the throat during swallowing, it is not solely responsible for preventing the entry of the bolus into the trachea. Therefore, Option E is not the correct answer.

Q51. Net ATP produced at the end of glycolysis:

A. 2 ATP✓
B. 4 ATP
C. 6 ATP
D. 3 ATP
E. 8 ATP

Explanation: One glucose molecule yields four ATP molecules in total during glycolysis. Since 2 ATP molecules are used up in the first phase of glycolysis, there is a net gain of 2 ATP molecules.

Why the other options are wrong

B. It is not the correct quantity of ATP produced at end of glycolysis.
C. It is not the correct quantity of ATP produced at end of glycolysis.
D. It is not the correct quantity of ATP produced at end of glycolysis.
E. It is not the correct quantity of ATP produced at end of glycolysis.

Q52. Spikelet inflorescence is the characteristic of:

A. Solanaceae
B. Rosaceae
C. Fabcene
D. Poaceae✓

Explanation: The correct answer is D Poaceae. Spikelet inflorescence is a characteristic feature of the family Poaceae, also known as the grass family or the true grasses. The spikelet is a specialized type of inflorescence found in grasses, where it consists of a cluster of florets arranged along a central axis.

Why the other options are wrong

A. Solanaceae is a family of flowering plants that includes many well-known species such as tomato, potato, and eggplant. However, spikelet inflorescence is not a characteristic typically associated with plants in the Solanaceae family. Therefore, Option A is not the correct answer.
B. Rosaceae is a family of flowering plants that includes roses, apples, and strawberries. Spikelet inflorescence is not a characteristic commonly found in plants of the Rosaceae family. Therefore, Option B is not the correct answer.
C. Fabcene does not appear to be a recognized term or plant family name. Without further context or information, it is not possible to provide a specific explanation for Option C.

Q53. Each myosin is surrounded by:

A. Motor nerves
B. Myosin head
C. 6-actin filaments✓
D. 2-actin filaments
E. 4- actin Filaments

Explanation: The correct answer is C 6-actin filaments, as each myosin filament is surrounded by six actin filaments in the sarcomere.

Why the other options are wrong

A. Myosin is not surrounded by motor nerves.
B. Myosin is not surrounded by a myosin head.
D. Myosin is not surrounded by 2-actin filaments.
E. Myosin is not surrounded by 4-actin filaments.

Q54. Synthesis of a disaccharide by condensation of two glucose molecules joined by a glycosidic linkage to form:

A. Galactose
B. Lactose
C. Fructose
D. Maltose✓

Explanation: The correct answer is E Maltose. Maltose is a disaccharide composed of two glucose molecules joined by a glycosidic linkage. This linkage is commonly referred to as an α(1→4) glycosidic bond in maltose.

Why the other options are wrong

A. Galactose is a monosacchride. A is the incorrect option. Maltose is produced when two glucose molecules join through a glycosidic bond during a condensation reaction. \
B. Lactose is a disacchride formed by two monosacchrides lactose and glucose joined through a glycosidic bond. B is the incorrect option.
C. Fructose is a monosacchride. C is the incorrect option. Maltose is produced when two glucose molecules join through a glycosidic bond during a condensation reaction.

Q55. White-eyed trait in drosophila is due to:

A. Linkage
B. Mutation✓
C. Crossing over
D. Genome
E. Gene pool

Explanation: The correct answer is b) Mutation. The white-eyed trait in Drosophila (fruit flies) is primarily due to a mutation. In the wild type, Drosophila typically has red eyes. However, a spontaneous mutation occurred in the X chromosome of a male fruit fly, resulting in a gene alteration that caused the eye colour to change to white. This mutation is inherited as an X-linked recessive trait.

Why the other options are wrong

A. Option A is not the correct answer in this case. Linkage refers to the tendency of genes to be inherited together because they are located close to each other on the same chromosome. While the white-eyed trait in Drosophila is indeed due to a genetic phenomenon, it is not specifically caused by linkage.
C. Crossing over is a process that occurs during meiosis, where genetic material is exchanged between homologous chromosomes. While crossing over can lead to genetic recombination and the generation of new combinations of alleles, it is not directly responsible for the white-eyed trait in Drosophila. The white-eyed trait is primarily caused by a mutation in a specific gene, as mentioned in Option B.
D. The genome refers to the complete set of genetic material (DNA) of an organism. While variations in the genome can contribute to different traits, including eye colour, the white-eyed trait in Drosophila is specifically caused by a mutation in a gene rather than a characteristic of the entire genome. Therefore, Option D is not the correct answer.
E. The gene pool refers to the total collection of different genes and their alleles in a population. While the gene pool can influence the genetic variation within a population, it does not specifically explain the white-eyed trait in Drosophila. The white-eyed trait is primarily caused by a mutation in a specific gene, as mentioned in Option B.

Q56. Enzymes are generally inactivated rapidly by exposure to UV high and also a, ẞ rays because it alters the:

A. Quantity of enzyme
B. pH of enzyme
C. Shape of enzymes✓
D. Temperature of enzyme
E. Nature of enzyme

Explanation: Exposure to UV, high-energy, and ionizing radiation, such as X-rays and gamma rays, can cause damage to enzymes and other biomolecules. The primary mechanism by which these radiations affect enzymes is by altering their molecular structure or shape. Therefore option C is correct.

Why the other options are wrong

A. It is not altered by UV rays or beta rays.
B. It is not altered by UV rays or beta rays.
D. It is not altered by UV rays or beta rays.
E. It is not altered by UV rays or beta rays.

Q57. In frogs, new air is drawn into the buccopharyngeal cavity through the nostrils, and old air is retained under pressure in:

A. Lungs✓
B. Nasal
C. Glottis
D. Trachea
E. Nostrils

Explanation: The correct answer is A Lungs. In frogs, the process of respiration involves the use of both the nostrils and the lungs. When a frog breathes, new air is drawn into the bucco-pharyngeal cavity (the oral cavity and pharynx) through the nostrils. From there, the air moves into the lungs for gas exchange.

Why the other options are wrong

B. Option B is not the correct answer. "Nasal" typically refers to the nose or the nasal cavity. While new air is drawn into the buccopharyngeal cavity through the nostrils, old air is not retained in the nasal cavity under pressure.
C. The glottis is the opening of the respiratory passage in frogs, located in the throat region. It functions as a valve that opens during breathing to allow air to pass into the lungs and closes during swallowing to prevent food from entering the respiratory system. However, the glottis is not responsible for retaining old air under pressure. Instead, it plays a role in controlling the passage of air into and out of the respiratory system. Therefore, Option C is not the correct answer.
D. Option D is not the correct answer. The trachea, also known as the windpipe, is a respiratory tube in vertebrates that connects the larynx to the lungs. In frogs, the trachea plays a role in conducting air to and from the lungs, but it is not directly involved in retaining old air under pressure.
E. Option E is not the correct answer. Nostrils, also known as nares, are the external openings of the nasal passages through which air is drawn into the buccopharyngeal cavity. While they are involved in the initial intake of new air, they are not responsible for retaining old air under pressure.

Q58. Class turbellaria, trematoda and cestoda belong to phylum:

A. Echinodermata
B. Porifera
C. Aschelminthes
D. Cnidaria
E. Platyhelminthes✓

Explanation: The correct answer is Platyhelminthes. Option E The classes Turbellaria, Trematoda, and Cestoda belong to the phylum Platyhelminthes. Platyhelminthes, commonly known as flatworms, is a phylum of invertebrates characterized by their flattened body shape. The class Turbellaria includes free-living flatworms that are often found in freshwater or marine environments.

Why the other options are wrong

A. These classes do not belong to this phylum. Echinodermata is a different phylum that includes marine animals like starfish and sea urchins.
B. These classes do not belong to this phylum. Phylum Porifera includes sponges, while Platyhelminthes is the phylum for flatworms, which are further divided into these classes.
C. These classes do not belong to this phylum.
D. These classes do not belong to Cnidarians.Cnidarians, such as jellyfish and corals, are a separate phylum with a distinct body structure, unlike flatworms, which are characterized by a three-layered body, bilateral symmetry, and lack of a body cavity.

Q59. Genetic Information in DNA is stored in the form of:

A. Genetic code✓
B. Chromosome
C. Amino acid
D. Helix

Explanation: The correct answer is A Genetic code. Genetic information in DNA is stored in the form of a genetic code. The genetic code is the set of rules that specifies how the sequence of nucleotides in DNA is translated into the sequence of amino acids in a protein. It is the basis for the transmission of genetic information from one generation to the next and is responsible for the diversity of life.

Why the other options are wrong

B. Chromosomes are structures within cells that contain DNA. They consist of long strands of DNA wound around proteins called histones. While chromosomes carry genetic information, they are not the direct storage form of genetic information. The genetic information within chromosomes is encoded in the DNA molecule itself, which is the subject of this question.
C. Amino acids are the building blocks of proteins, and they are synthesized based on the genetic information stored in DNA. However, DNA does not directly store genetic information in the form of amino acids. The sequence of amino acids in a protein is determined by the sequence of nucleotides in DNA, which is then translated into proteins during protein synthesis.
D. The DNA molecule has a double helix structure, which refers to the twisted ladder-like shape formed by two complementary strands of nucleotides. While the helical structure is a characteristic of DNA, it is not the form in which genetic information is stored.

Q60. Pyruvic acid is acid of:

A. 4 carbon compound
B. 5 carbon compound
C. 6 carbon compound
D. 3 carbon compound✓

Explanation: The correct answer is E 3-carbon compound. Pyruvic acid is a three-carbon compound. It is an important intermediate product in the process of glycolysis, which is the initial step of cellular respiration. During glycolysis, glucose, a six-carbon compound, is broken down into two molecules of pyruvic acid. Each pyruvic acid molecule contains three carbons.

Why the other options are wrong

A. Option A is not the correct answer. Pyruvic acid is a 3-carbon compound. It is a key intermediate molecule formed during glycolysis, which is the initial step of glucose metabolism. Glucose, a 6-carbon compound, is broken down into two molecules of pyruvic acid, each containing 3 carbon atoms.
B. Option B is not the correct answer. Pyruvic acid is a 3-carbon compound.
C. Option C is not the correct answer. Pyruvic acid is not a 6-carbon compound. Instead, it is a 3-carbon compound.

Q61. Plant cell wall is made up of:

A. Lignin
B. Hemicellulose
C. Cutin
D. Chitin
E. Cellulose✓

Explanation: The plant cell wall has a big portion of cellulose, which gives, rigidity, strength, and support to the cell. So option E is the correct option.

Why the other options are wrong

A. Option A is not the correct answer. Lignin is a complex polymer found in the secondary cell walls of some plant cells. It provides rigidity and strength to the cell walls of certain types of cells, such as those in woody plants. However, the primary component of the plant cell wall is not lignin.
B. Option B is not the correct answer. Hemicellulose is another type of polysaccharide present in plant cell walls. It contributes to the structural integrity of the cell wall and interacts with cellulose to form a matrix. However, it is not the main component of the plant cell wall.
C. Option C is not the correct answer. Cutin is a waxy substance that forms the cuticle, which is the outer layer of the epidermis in the leaves and stems of plants. The cuticle helps prevent water loss and provides protection, but it is not a major component of the plant cell wall.
D. Option D is not the correct answer. Chitin is a structural polysaccharide found in the cell walls of fungi and the exoskeletons of arthropods, such as insects and crustaceans. It is not a constituent of the plant cell wall.

Q62. Plant like character found in Euglena:

A. Pyrenoid✓
B. Cilia
C. Photoreceptor
D. Flagellum
E. Pellicle

Explanation: The correct answer is A Pyrenoid. One of the plant-like characteristics found in Euglena is the presence of a pyrenoid. A pyrenoid is an organelle located within the chloroplast of certain algae and plants.

Why the other options are wrong

B. Option B is not the correct answer. Cilia are hair-like structures found on the surface of some cells, primarily in animal cells. They are used for various functions, including movement, sensory perception, and fluid propulsion. Euglena does not have cilia. Instead, it has a flagellum, which is a whip-like structure used for movement.
C. Option C is not the correct answer. Euglena possesses a photoreceptor, which is a light-sensitive structure. This photoreceptor allows Euglena to detect changes in light intensity and helps the organism move towards light during phototaxis. However, photoreceptors are not specific to plant-like characteristics.
D. Option D is not the correct answer. Euglena has a whip-like flagellum that it uses for movement. The flagellum enables Euglena to propel itself through the water by beating in a whip-like motion. While the presence of a flagellum is characteristic of Euglena, it is not a plant-like characteristic.
E. Option E is not the correct answer. Euglena possesses a pellicle, which is a flexible outer covering or membrane. The pellicle provides structural support to the cell and helps maintain its shape. While the presence of a pellicle is a unique feature of Euglena, it is not a plant-like characteristic.

Q63. It has neurosecretory cells that secrete releasing & inhibiting hormones:

A. Pituitary gland
B. Thyroid gland
C. Adrenal gland
D. Master gland
E. Hypothalamus✓

Explanation: The correct answer is Hypothalamus, referring to option E. The hypothalamus is a region of the brain found in vertebrates. It is a crucial part of the neuroendocrine system and plays a major role in the regulation of various physiological processes, including hormone production and secretion.

Why the other options are wrong

A. Option A is not the correct answer. While the pituitary gland is an essential part of the endocrine system and plays a crucial role in regulating various hormones, it does not contain neurosecretory cells that secrete releasing and inhibiting hormones.
B. Option B is not the correct answer. The thyroid gland primarily produces thyroid hormones (thyroxine and triiodothyronine), which are involved in regulating metabolism. It does not contain neurosecretory cells that release and inhibit hormones.
C. Option C is not the correct answer. The adrenal glands produce hormones such as cortisol, adrenaline (epinephrine), and aldosterone. They are involved in the body's stress response and maintaining fluid balance, but they do not contain neurosecretory cells that secrete releasing and inhibiting hormones.
D. Option D is not the correct answer. The term "master gland" is sometimes used to refer to the pituitary gland because it plays a central role in regulating other endocrine glands. However, the pituitary gland itself does not secrete releasing and inhibiting hormones.

Q64. It is the seat of all conscious activity:

A. Hind brain
B. Cortex✓
C. Spinal cord
D. Mid brain
E. Medulla oblongata

Explanation: The cortex plays a crucial role in various conscious activities such as perception, attention, memory, language, reasoning, decision-making, and voluntary movement. It is involved in sensory processing, interpretation of sensory information, and integration of multiple sensory inputs.

Why the other options are wrong

A. Option A is not the correct answer. The hindbrain, also known as the rhombencephalon, is a region of the brain that includes the cerebellum, pons, and medulla oblongata. While the hindbrain is essential for various functions such as coordination, balance, and vital reflexes, it is not the seat of all conscious activity.
C. Option C is not the correct answer. The spinal cord is a long, thin, tubular bundle of nerves that extends from the brainstem to the lower back. It serves as a communication pathway between the brain and the rest of the body and is responsible for relaying sensory and motor signals. However, it is not the primary seat of conscious activity.
D. Option D is not the correct answer. The midbrain, also known as the mesencephalon, is a small part of the brainstem that plays a role in relaying sensory and motor information. It is involved in functions such as visual and auditory processing, eye movement control, and coordination. However, it is not the seat of all conscious activity.
E. Option E is not the correct answer. The medulla oblongata is the lowermost part of the brainstem, and it controls vital functions such as breathing, heart rate, and blood pressure. While the medulla oblongata is essential for maintaining life, it is not the primary seat of conscious activity.

Q65. The common energy currency of the cell is:

A. NHDP
B. ADP
C. ATP✓
D. NADH

Explanation: ATP stands for adenosine triphosphate, which is a molecule that serves as the primary energy currency in living organisms. It is often referred to as the "energy currency" because it stores and releases energy as needed for cellular processes. Therefore option C is correct.

Why the other options are wrong

A. Option A is not the correct answer. NHDP is not a known energy currency in the cell. It seems to be an incorrect option.
B. Option B is not the correct answer. ADP stands for adenosine diphosphate. It is an important molecule involved in cellular energy metabolism. When ATP (adenosine triphosphate) releases energy for cellular processes, it becomes ADP by losing one phosphate group. ADP can then be further converted back to ATP through the addition of a phosphate group during cellular respiration or photosynthesis.
D. Option D is not the correct answer. NADH stands for nicotinamide adenine dinucleotide (NAD+) in its reduced form. It is a coenzyme involved in cellular respiration and plays a crucial role in transferring electrons during the production of ATP. While NADH is involved in energy metabolism, it is not the primary energy currency of the cell.

Q66. Scorpioid chyme is found in:

A. Cotton✓
B. Mulberry
C. Sunflower
D. Sundew
E. Banana

Explanation: A scorpoid cyme is characterized by a coiled or helical arrangement of flower clusters that resemble the shape of a scorpion's tail. Hence the name "scorpoid." the sunflower (Helianthus) is known to exhibit a scorpoid cyme inflorescence. It is present in cotton. So option A is the correct option.

Why the other options are wrong

B. Option B is not the correct answer. Mulberry is a plant that belongs to the family Moraceae. The inflorescence of mulberry is usually a catkin or a multiple fruit, not a scorpioid cyme
C. Option C is not the correct answer. Sunflower is a plant that belongs to the family Asteraceae. The inflorescence of sunflowers is a capitulum, which consists of many tiny individual flowers arranged in a disc surrounded by ray florets. It is not a scorpioid cyme.
D. Option D is not the correct answer. Sundew is a carnivorous plant that belongs to the family Droseraceae. The inflorescence of sundew is typically a raceme or a panicle, not a scorpioid cyme.
E. Instead, banana plants have a different type of inflorescence known as a compound raceme or a compound panicle. The banana inflorescence consists of several bracts that protect the flowers arranged in a raceme or panicle.

Q67. Bacteria having flagella all over the surface:

A. Lophotrichous
B. Peritrichous✓
C. Atrichous
D. Monotrichous
E. Diplotrichous

Explanation: Peritrichous bacteria are those that have flagella distributed all over their surface. The term "peritrichous" comes from the Greek words "peri", meaning "around", and "trichos", meaning "hair," indicating that the flagella are present around the entire surface of the bacterial cell. Source :

Why the other options are wrong

A. Bacteria with flagella located at one or both ends of the cell.
C. Atrichous bacteria are those that lack flagella or have very few flagella on their surface.
D. Bacteria with a single flagellum at one end of the cell.
E. Bacteria with two flagella located at one or both ends of the cell.

Q68. A hormone secreted from the duodenal mucosa that changes the inactive trypsinogen into trypsin is:

A. Peptone
B. Ecdysone
C. Enterokinase✓
D. Amylase
E. Protease

Explanation: The correct answer is C Enterokinase. Enterokinase, also known as enteropeptidase, is an enzyme that is produced and secreted by the cells of the duodenal mucosa (lining of the duodenum). It plays a crucial role in the digestion of proteins by converting the inactive pancreatic zymogen called trypsinogen into its active form, trypsin.

Why the other options are wrong

A. Peptone is not the correct answer. Peptone is a protein derivative obtained by breaking down proteins through enzymatic digestion or acid hydrolysis. It is commonly used as a nutrient source in microbiological culture media, but is not involved in converting trypsinogen into trypsin.
B. Ecdysone is not the correct answer. Ecdysone is a hormone involved in the moulting process of arthropods, such as insects and crustaceans. It plays a role in regulating the shedding of their exoskeleton during growth and development.
D. Amylase is not the correct answer. Amylase is an enzyme involved in the breakdown of starch and glycogen into simpler sugars like maltose. It is produced in the salivary glands and pancreas, but is not responsible for converting trypsinogen into trypsin.
E. Protease is not the correct answer. Protease is a general term for enzymes that break down proteins into smaller peptides or amino acids. While it plays a crucial role in protein digestion, it is not the specific hormone responsible for converting trypsinogen into trypsin.

Q69. Endocytosis which involve ingestion of solid material is called:

A. Solidocytosis
B. Phagocytosis✓
C. Exocytosis
D. Pinocytosis
E. Autocytosis

Explanation: Phagocytosis is the process that involve ingestion of solid food material into the cell. Therefore the correct option is B.

Why the other options are wrong

A. No such term exists.
C. Exocytosis is the process by which a cell releases substances, such as waste products or secretory molecules, from vesicles into the external environment.
D. Pinocytosis is the process by which a cell engulfs liquid substances or dissolved solutes into small vesicles for internalization and nutrient uptake.
E. No such term exists.

Q70. Plant-like protists are called:

A. Bryophytes
B. Bacteria
C. Fungi
D. Tracheophytes
E. Algae✓

Explanation: Algae are plant-like protists. Therefore option E is the correct answer among all other given options.

Why the other options are wrong

A. Option A is not the correct answer. Bryophytes are not plant-like protists. They are a group of non-vascular plants that include mosses, liverworts, and hornworts. Bryophytes have simple structures and lack true roots, stems, and leaves. They reproduce by spores and often grow in moist environments.
B. Option B is not the correct answer. Bacteria are not plant-like protists. They are prokaryotic microorganisms, distinct from eukaryotic protists and plants. Bacteria are unicellular and have a simple cell structure without a nucleus or membrane-bound organelles.
C. Option C is not the correct answer. Fungi are not plant-like protists, either. They are a separate kingdom of eukaryotic organisms that includes mushrooms, yeasts, and molds. Fungi are heterotrophs, meaning they obtain nutrients by absorbing organic matter from their surroundings.
D. Option D is not the correct answer. Tracheophytes are also not plant-like protists. They are vascular plants that include ferns, gymnosperms, and angiosperms. Tracheophytes have specialized vascular tissues (xylem and phloem) that allow them to transport water and nutrients throughout their bodies.

Q71. When substrate combines the active site of an enzyme it induces a conformational changes that enable enzyme to perform:

A. Analytic function
B. Metabolism
C. Meiosis
D. Mitosis
E. Catalytic function✓

Explanation: When substrate combines the active site of an enzyme it induces a conformational changes that enable enzyme to perform catalytic function. So Option E is the correct option.

Why the other options are wrong

A. Option A is not the correct answer. Analytic function is not a term commonly used in the context of enzyme-substrate interactions. Enzymes do not typically have an analytic function in the sense described in this question.
B. Option B is not the correct answer. While enzymes play a critical role in metabolism by facilitating chemical reactions that break down or build molecules in cells, the term metabolism does not directly relate to the specific function of enzymes when the substrate binds to the active site.
C. Option C is not the correct answer. Meiosis is a specialized type of cell division that occurs during the formation of gametes (sperm and egg cells) in sexually reproducing organisms. It is not directly related to the function of enzymes and substrate binding.
D. Option D is not the correct answer. Mitosis is the process of cell division that results in two genetically identical daughter cells. Like meiosis, it is not directly related to the function of enzymes and substrate binding.

Q72. When substrate combines the active site of an enzyme, it induces a conformational changes that enable the enzyme to perform:

A. Analytic function
B. Metabolism
C. Meiosis
D. Mitosis
E. Catalytic function✓

Explanation: When substrate combines the active site of an enzyme it induces a conformational changes that enable enzyme to perform catalytic function. So Option E is the correct option.

Why the other options are wrong

A. Option A is not the correct answer. The analytic function is not a term commonly used in the context of enzyme-substrate interactions. Enzymes do not typically have an analytic function in the sense described in this question.
B. Option B is not the correct answer. While enzymes play a critical role in metabolism by facilitating chemical reactions that break down or build molecules in cells, the term metabolism does not directly relate to the specific function of enzymes when the substrate binds to the active site.
C. Option C is not the correct answer. Meiosis is a specialized type of cell division that occurs during the formation of gametes (sperm and egg cells) in sexually reproducing organisms. It is not directly related to the function of enzymes and substrate binding.
D. Option D is not the correct answer. Mitosis is the process of cell division that results in two genetically identical daughter cells. Like meiosis, it is not directly related to the function of enzymes and substrate binding.

Q73. Mendel's selected following pair(s) of contrasting character:

A. One single pair
B. Seven pairs✓
C. Three pairs
D. Four pairs
E. Two pairs

Explanation: As mentioned in STB , mendel selected seven pairs of contrasting character.

Why the other options are wrong

A. This is not the correct number of pairs selected.
C. This is not the correct number of pairs selected.
D. This is not the correct number of pairs selected.
E. This is not the correct number of pairs selected.

Q74. The powerhouse of the cell:

A. Ribosomes
B. Endoplasmic reticulum
C. Chloroplasts
D. Mitochondria✓
E. Leucoplast

Explanation: Mitochondria are regarded as powerhouse of cells that generates ATP for different cell processes. Therefore option D is the correct answer.

Why the other options are wrong

A. Mitochondria are the powerhouse of the cell because they produce ATP through cellular respiration, supplying energy for all cellular activities. Ribosomes are not correct because they synthesize proteins, not energy.
B. Endoplasmic reticulum (ER) is not the powerhouse of the cell. Rough ER synthesizes and processes proteins, while Smooth ER is involved in lipid synthesis and detoxification, but neither produces ATP. Mitochondria remain the correct answer as they generate cellular energy.
C. Chloroplasts are not the powerhouse of the cell. They carry out photosynthesis in plant cells, converting sunlight into chemical energy (glucose), but they do not directly produce ATP for general cellular activities like mitochondria do. Mitochondria remain the correct answer.
E. Leucoplasts are colorless plastids found in plants, primarily involved in storing starch, oils, and proteins, and do not produce energy. Mitochondria remain the correct answer as the powerhouse of the cell.

Q75. The tidal volume of lungs at rest or during normal breath is:

A. 4 liters
B. 6 liters
C. 0.5 liters✓
D. 3 liters

Explanation: Tidal volume refers to the volume of air that is inspired or expired during a normal breath, without any extra effort or forceful breathing. It represents the amount of air that moves in and out of the lungs with each breath during quiet breathing or at rest, and the tidal volume of lungs at rest or during normal breath is 0.5 liters or 500mL. So option B is the correct answer.

Why the other options are wrong

A. This is not the correct tidal volume of lungs at rest or during normal breath. Tidal volume is the amount of air inhaled or exhaled during a normal, relaxed breath without any extra effort. It reflects the air exchanged with each breath at rest, and in an average adult, this volume is about 0.5 liters (500 mL). Therefore, option B is correct.
B. This is not the correct tidal volume of lungs at rest or during normal breath. Tidal volume is the quantity of air taken in or expelled during a regular, effortless breath. In a resting adult, this volume is approximately 0.5 liters (500 mL) per breath. Hence, option B is the correct choice.
D. This is not the correct tidal volume of lungs at rest or during normal breath. Tidal volume is the amount of air that moves into or out of the lungs during a normal, unforced breath. For an average adult at rest, this volume is around 0.5 liters (500 mL), making option B the correct answer.

Q76. They detect pain and tissue damage:

A. Baroreceptors
B. Chemoreceptor
C. Photoreceptor
D. Noiceceptor✓
E. Mechanoreceptor

Explanation: Nociceptors, also known as pain receptors, are specialized sensory receptors that detect pain and tissue damage. They are found throughout the body, including the skin, internal organs, and tissues. Therefore, option D is the correct answer.

Why the other options are wrong

A. Option A is not the correct answer. Baroreceptors are sensory receptors that detect changes in blood pressure. They are primarily found in the walls of blood vessels and the heart. Baroreceptors are not responsible for detecting pain and tissue damage.
B. Option B is not the correct answer. Chemoreceptors are sensory receptors that detect changes in chemical concentrations, such as the levels of oxygen, carbon dioxide, and pH in the blood. They are found in various organs, including the respiratory system and blood vessels. Chemoreceptors are not involved in detecting pain and tissue damage.
C. Option C is not the correct answer. Photoreceptors are sensory receptors that detect light and are primarily found in the eyes. They are responsible for vision and are not involved in detecting pain and tissue damage.
E. Option E is not the correct answer. Mechanoreceptors are sensory receptors that respond to mechanical stimuli, such as pressure, touch, and vibration. They are found throughout the body, including the skin and internal organs. Mechanoreceptors are not specialized for detecting pain and tissue damage.

Q77. Phenotypic ratio of single trait inheritance:

A. 1:2:1
B. 3:1✓
C. 1:2
D. 1:3:2
E. 1:1

Explanation: Phenotypic ratio of single trait inheritance is 3:1. So the correct option is B.

Why the other options are wrong

A. This is not the phenotypic ratio of single trait inheritance.
C. This is not the phenotypic ratio of single trait inheritance.
D. This is not the phenotypic ratio of single trait inheritance.
E. This is not the phenotypic ratio of single trait inheritance.

Q78. Artificial selection in breeding provides evidence for evolution known as:

A. Domestication✓
B. Deme
C. Gene pool
D. Desire trait
E. Genetic death

Explanation: One of the most notable examples of artificial selection is domestication, where humans have selectively bred plants and animals to suit their needs and preferences. Domestication has resulted in the development of various breeds and varieties that differ significantly from their wild ancestors. So option A is the correct answer.

Why the other options are wrong

B. Option B is not the correct answer. A deme is a local population of organisms with shared characteristics. It is not directly related to the evidence for evolution through artificial selection.
C. Option C is not the correct answer. The gene pool refers to the total set of genes and alleles present in a population of organisms. While artificial selection can affect the gene pool of a population, it is not the specific term used to describe the evidence for evolution through artificial selection.
D. Option D is not the correct answer. While artificial selection involves choosing organisms with specific desired traits for breeding, "desired trait" is not the term used to describe the evidence for evolution through artificial selection.
E. Option E is not the correct answer. "Genetic death" is not a term used in the context of evidence for evolution through artificial selection. It does not accurately describe the process of artificial selection or its role in providing evidence for evolution.

Q79. Molecules of amylose consists of unbranched chains of hundreds of glucose subunits, join together by:

A. 1-2 glycosidic linkage
B. 2-3 glycosidic linkage
C. 1-4 glycosidic linkage✓
D. 1-3 glycosidic linkage
E. 1-6 glycosidic linkage

Explanation: Molecules of amylose consists of unbranched chains of hundreds of glucose subunits, join together by 1-4 glycosidic linkage, thus option C is the correct answer.

Why the other options are wrong

A. Option A is not the correct answer. A 1-2 glycosidic linkage refers to a type of bond between two sugar molecules (in this case, glucose) where the linkage occurs between the first carbon (C1) of one sugar and the second carbon (C2) of another sugar. This linkage is not involved in the formation of amylose molecules.
B. Option B is not the correct answer. A 2-3 glycosidic linkage refers to a type of bond between two sugar molecules where the linkage occurs between the second carbon (C2) of one sugar and the third carbon (C3) of another sugar. This linkage is not involved in the formation of amylose molecules.
D. Option D is not the correct answer. A 1-3 glycosidic linkage refers to a type of bond between two sugar molecules where the linkage occurs between the first carbon (C1) of one sugar and the third carbon (C3) of another sugar. This linkage is not involved in the formation of amylose molecules.
E. Option E is not the correct answer. A 1-6 glycosidic linkage refers to a type of bond between two sugar molecules where the linkage occurs between the first carbon (C1) of one sugar and the sixth carbon (C6) of another sugar. This linkage is typically found in the branching points of polysaccharides like glycogen and amylopectin but is not present in amylose.

Q80. It provides protection of coastline from the storm, shelter for marine organisms, assisting carbon & nitrogen-fixing:

A. Polyps
B. Coral reefs✓
C. Medusa
D. Aurelia
E. Hydra

Explanation: Coral reefs are diverse underwater ecosystems built by colonies of tiny animals called coral polyps. They provide numerous benefits to the marine environment and human populations. Therefore, option B is the correct answer.

Why the other options are wrong

A. Option A is not the correct answer. Polyps are cylindrical, sessile (non-moving) forms of cnidarians that are typically attached to a substrate. While polyps are an important life stage of some cnidarians, they do not provide protection of coastlines from storms or shelter for marine organisms.
C. Option C is not the correct answer. Medusa is the umbrella-shaped, free-swimming life stage of cnidarians such as jellyfish. While medusae are a part of the life cycle of certain cnidarians, they do not protect coastlines from storms or assist in carbon and nitrogen-fixing.
D. Option D is not the correct answer. Aurelia is the scientific name for the moon jellyfish, which is a type of medusa. Similar to Option C, moon jellyfish are not known for providing protection of coastlines or assisting in carbon and nitrogen-fixing.
E. Option E is not the correct answer. Hydra is a freshwater polyp and belongs to the class Hydrozoa. While hydra is a fascinating organism, it does not form coral reefs and does not have a direct role in providing protection of coastlines or assisting in carbon and nitrogen-fixing.

Q81. Each enzyme has a dimple or groove at a specific side called:

A. Co-factor
B. Active site✓
C. Non active site
D. Substrate
E. Prosthetic group

Explanation: Each enzyme has a dimple or groove at a specific side called active site. This is where all the catalytic activity occurs. So option B is correct.

Why the other options are wrong

A. Option A is not the correct answer. A co-factor is a non-protein molecule or ion that is required for the proper functioning of some enzymes. Co-factors can bind to enzymes and assist in their catalytic activity, but they are not specifically located in a dimple or groove on the enzyme.
C. Option C is not the correct answer. While enzymes do have regions other than the active site, the term "non-active site" is not commonly used to describe a specific feature or location on the enzyme.
D. Option D is not the correct answer. The substrate is the specific molecule that binds to the active site of an enzyme and undergoes a chemical reaction. It is not a dimple or groove on the enzyme itself.
E. Option E is not the correct answer. A prosthetic group is a non-protein molecule that is permanently attached to an enzyme and is necessary for its function. Prosthetic groups are not located in a dimple or groove on the enzyme and are not directly involved in enzyme-substrate interactions.

Q82. Light reaction of photosynthesis takes place in:

A. Cristae
B. Stroma
C. Cisternae
D. Thylakoid✓

Explanation: Light reaction of photosynthesis takes place in the thylakoid membrane consisting of grana within it. So option D is the correct answer.

Why the other options are wrong

A. Option A is not the correct answer. Cristae are the folded inner membranes found in the mitochondria, not in the chloroplasts where photosynthesis occurs.
B. Option B is not the correct answer. The stroma is the gel-like fluid that fills the inner space of the chloroplasts, but the light reactions of photosynthesis do not occur here.
C. Option C is not the correct answer. Cisternae are flattened membrane sacs found in structures like the Golgi apparatus and the endoplasmic reticulum, but they are not involved in the light reactions of photosynthesis.

Q83. The vacated vesicular follicle forms a yellow structure on ovary called as:

A. Graafian luteum
B. Corpus luteum✓
C. Ruptured ovum
D. Follicle
E. Progestrone

Explanation: After the release of an egg during ovulation, the follicle from which the egg was released undergoes a transformation and forms a structure called the corpus luteum. The corpus luteum is a vacated vesicular follicle that forms a yellow structure on an ovary. It secretes hormones, primarily progesterone, which is important for preparing and maintaining the uterus for possible pregnancy. So option B is correct.

Why the other options are wrong

A. Option A is not the correct answer. The term "Graafian luteum" is not a commonly used term.
C. Option C is not the correct answer. An ovum refers to an egg cell released from the ovary during ovulation. The term "ruptured ovum" does not accurately describe the yellow structure that forms on the ovary after ovulation.
D. Option D is not the correct answer. The follicle is the structure in the ovary that contains the developing egg. After ovulation, the follicle collapses and transforms into the corpus luteum, which is the yellow structure formed on the ovary.
E. Option E is not the correct answer. Progesterone is a hormone produced by the corpus luteum. While it is related to the process, it is not the term used to describe the yellow structure formed on the ovary after ovulation.

Q84. Achatina fulica Is an giant snail that is dangerous:

A. For agricultural pest✓
B. For silk worm
C. For paper industry
D. For sericulture pest

Explanation: Achatina fulica Is a giant snail that is a dangerous agricultural pest. So Option A is the correct answer.

Why the other options are wrong

B. Achatina fulica is not dangerous for silk worm.
C. Achatina fulica is not dangerous for paper industry.
D. Achatina fulica is not dangerous for sericulture pest.

Q85. There is swelling and tenderness of one or more joints. The disease is:

A. Disc slip
B. Rickets
C. Spondylosis
D. Arthritis✓
E. Sciatica

Explanation: In arthritis, excessive calcium deposition occurs, which makes the bone hard. Thus option D is correct.

Why the other options are wrong

A. Option A is not the correct answer. A disc slip, also known as a herniated or slipped disc, refers to a condition where the soft cushion-like discs between the vertebrae in the spine become damaged or displaced. It is not related to the deposition of calcium in the bones.
B. Option B is not the correct answer. Rickets is a disease primarily seen in children that results from a deficiency of vitamin D, calcium, or phosphate. It leads to weak and soft bones, which can deform and cause skeletal abnormalities. In rickets, the deposition of calcium in the bones is impaired, leading to inadequate hardening of the bone tissue.
C. Option C is not the correct answer. Spondylosis is a degenerative condition that affects the spine, particularly the joints and discs between the vertebrae. It is characterized by wear and tear, degeneration, and changes in the spine, but it does not involve the deposition of calcium, which makes the bone hard.
E. Option E is not the correct answer. Sciatica is a condition characterized by pain, numbness, or weakness that originates in the lower back and radiates down the buttocks and into the leg. It is usually caused by compression or irritation of the sciatic nerve, but it is not related to the deposition of calcium in the bones.

Q86. Endocytosis which involves ingestion of solid material is called:

A. Solidocytosis
B. Phagocytosis✓
C. Exocytosis
D. Pinocytosis
E. Autocytosis

Explanation: Phagocytosis involves the ingestion of solid food material into the cell. So option B is the correct option.

Why the other options are wrong

A. No such term exists.
C. It is egestion of substances from cell.
D. It is termed as taking fluid particles into the cells.
E. No such term exists.

Q87. Viscosity is the measure of:

A. Volume
B. Resistance in the flow of a liquid✓
C. Fluidity of liquid
D. Mass
E. Density

Explanation: According to the definition mentioned in STB, option B is correct.

Why the other options are wrong

A. Option A is not the correct answer. Viscosity is not a measure of volume. Volume refers to the amount of space occupied by a substance, while viscosity is related to how easily a liquid flows.
C. Option C is not the correct answer. While fluidity is related to how easily a liquid flows, viscosity specifically quantifies the resistance to flow. So, fluidity and viscosity are related but distinct concepts.
D. Option D is not the correct answer. Viscosity is not related to the mass of a substance. Mass refers to the amount of matter in an object, while viscosity measures how resistant the fluid is to flow.
E. Option E is not the correct answer. Viscosity is not a measure of density. Density refers to the mass of a substance per unit volume, while viscosity measures how easily a liquid flows.

Q88. Acetone gives:

A. Fehling solution test positive
B. Silver mirror test positive
C. Lucas test positive
D. Iodoform test positive✓
E. Benedicts test positive

Explanation: Acetone reacts with excess iodine in a basic condition to form the carboxylic acid with one less carbon (ethanoic acid), and a yellow precipitate of iodoform is obtained. Thus acetone will give a positive iodoform test due to the formation of iodoform (triiodomethane) when reacted with excess iodine in basic conditions.

Why the other options are wrong

A. Acetones, in general, do not respond to Fehling's test, because they do not have the hydrogen (attached to the carbon–oxygen double bond which is present in aldehydes) which will undergo oxidation, hence it is difficult to oxidise them with this solution.
B. Silver mirror test positive is incorrect because acetone, being a ketone, does not give a positive silver mirror test. Only aldehydes can reduce Tollens' reagent to form a silver mirror.
C. Option C is not the correct answer. The Lucas test is used to distinguish between primary, secondary, and tertiary alcohols based on their reactivity with the Lucas reagent (a mixture of zinc chloride and hydrochloric acid). Acetone, being a ketone, does not give a positive Lucas test.
E. Option E is not the correct answer. Benedict's reagent is used to test for the presence of reducing sugars (such as glucose) in a solution. Acetone, being a ketone, does not give a positive Benedict's test.

Q89. The equation v= RH(½^2-1/n^2) where n>2 is the equation of H spectrum of:

A. Paschen series
B. Pfund series
C. Bracket series
D. Lyman series
E. Balmer series✓

Explanation: The above equation is of the Balmer series, thus option E is the correct answer.

Why the other options are wrong

A. The Paschen series corresponds to electronic transitions in the Hydrogen atom where the electron jumps from higher energy levels (n > 3) to the third energy level (n = 3). The Paschen series emits photons in the infrared region of the electromagnetic spectrum.
B. The Pfund series corresponds to electronic transitions in the Hydrogen atom where the electron jumps from higher energy levels (n > 4) to the fourth energy level (n = 4). The Pfund series also emits photons in the infrared region of the electromagnetic spectrum.
C. The Brackett series corresponds to electronic transitions in the Hydrogen atom where the electron jumps from higher energy levels (n > 5) to the fifth energy level (n = 5). The Brackett series emits photons in the infrared region of the electromagnetic spectrum.
D. The Lyman series corresponds to electronic transitions in the Hydrogen atom where the electron jumps from higher energy levels (n > 1) to the first energy level (n = 1). The Lyman series emits photons in the ultraviolet region of the electromagnetic spectrum.

Q90. The equation of the first law of thermodynamics q=AE+W, will reduce at constant volume to:

A. ΔE+W
B. qv = E +PΔV
C. qv= E+W
D. qv = E✓
E. qv = PΔGV

Explanation: The equation of the first law of thermodynamics, q = ΔE + W, reduces at constant volume to qv = ΔE.At constant volume (no work is done), the work term (W) becomes zero. Therefore, the equation simplifies to qv = ΔE, where qv represents the heat transfer at constant volume, and ΔE represents the change in internal energy. Therefore option D is the correct answer.

Why the other options are wrong

A. This option is incorrect because it is the same as the original equation and does not represent a reduction at constant volume.
B. This option is also incorrect. The term "qv" represents heat transferred at constant volume, and "PΔV" represents work done during a change in volume. The correct equation for the first law of thermodynamics at constant volume is simply qv = ΔE, as no work is done at constant volume (ΔV = 0).
C. This option is the same as the original equation and is incorrect for the same reason as Option A.
E. This option is incorrect. "PΔGV" does not represent the work done at constant volume; it appears to be a combination of pressure (P) and change in Gibbs free energy (ΔG). The correct equation for the first law of thermodynamics at constant volume is qv = ΔE, as mentioned in Option D.

Q91. The electrolysis of dilute hydrochloric acid solution gives:

A. Cl2 at cathode & H2 at anode
B. H2 at cathode & O2 at anode✓
C. None of these
D. H2 at anode & Na at cathode
E. H2 at anode & O2 cathode

Explanation: During the electrolysis of dilute hydrochloric acid, the process involves the splitting of water molecules and ions in the solution. At the cathode (negative electrode), hydrogen ions (H+) gain electrons to form hydrogen gas (H2). At the anode (positive electrode), hydroxide ions (OH-) lose electrons, which leads to the formation of oxygen gas (O2). Thus, the correct products are hydrogen at the cathode and oxygen at the anode (Option B). Option A is incorrect because chlorine gas is not produced at the cathode in this scenario. Option C is identical to the correct answer and should be considered redundant. Option D is incorrect as sodium does not form in the electrolysis of hydrochloric acid. Option E is also incorrect as hydrogen is not formed at the anode. Therefore, Option B is the only correct answer.

Why the other options are wrong

A. This option is incorrect. During electrolysis of dilute hydrochloric acid, chlorine gas (Cl2) is produced at the anode, not the cathode.
C. This is not correct as there is indeed an correct option.
D. This option is incorrect. Sodium (Na) does not get discharged in electrolysis of dilute hydrochloric acid; instead, hydrogen is formed at the cathode.
E. This option is incorrect. Hydrogen is produced at the cathode, not the anode, during the electrolysis of dilute hydrochloric acid.

Q92. Oswald's process the oxidation of:

A. H2S
B. NH3✓
C. H2SO4
D. HNO3
E. Cl2

Explanation: The oxidation of ammonia takes place, and it is converted into nitric oxide (NO). The process is reversible and exothermic. The change in temperature encourages a forward reaction.

Why the other options are wrong

A. Oswald's process is not the oxidation of H2S.
C. Oswald's process is not the oxidation of H2SO4.
D. Oswald's process is not the oxidation of HNO3.
E. Oswald's process is not the oxidation of Cl2.

Q93. The dipolar moment of CO2 is zero because it is:

A. Angular
B. Linear✓
C. Triatomic
D. Pyramidal
E. CO is polar

Explanation: The correct answer is option (B): Linear. The dipole moment of a molecule depends on the polarity of its bonds and the molecular geometry. In the case of CO2 (carbon dioxide), it has a linear molecular geometry due to the arrangement of the atoms. The carbon atom is located in the centre, with two oxygen atoms bonded to it on opposite sides.

Why the other options are wrong

A. "Angular" refers to a molecular geometry where the central atom is surrounded by two or more bonded atoms, creating a bent or V-shaped structure. CO2 is a linear molecule, not angular, so this option is not correct.
C. "Triatomic" simply means a molecule composed of three atoms. While CO2 is a triatomic molecule, this option does not address the reason for its zero dipole moment.
D. "Pyramidal" refers to a molecular geometry where the central atom is surrounded by three bonded atoms arranged in a pyramidal shape. This option does not apply to CO2, as CO2 has a linear geometry.
E. This option refers to the molecule CO, which is carbon monoxide. CO is indeed a polar molecule with a net dipole moment due to an unequal distribution of charge between the carbon and oxygen atoms. However, this option is not related to the explanation for why CO2 has a dipole moment of zero.

Q94. The two crystals Na NO3; & CaCO3, are both trigonal, they are:

A. Isomers
B. Polymorphs
C. Allotropes
D. Enantiomers
E. Isomorphs✓
F. None of the above

Explanation: NaNO2 and CaCO3 are isomorphs of each other.

Why the other options are wrong

A. The two crystals, "NaNO2" (sodium nitrite) and "CaCO3" (calcium carbonate) are not isomers. Isomers are different compounds that have the same molecular formula but different structural arrangements or connectivity of atoms.In this case, "NaNO2" and "CaCO3" are different chemical compounds with distinct molecular formulas and structures:"NaNO2" (sodium nitrite) has one sodium (Na) atom, one nitrogen (N) atom, and two oxygen (O) atoms."CaCO3" (calcium carbonate) consists of one calcium (Ca) atom, one carbon (C) atom, and three oxygen (O) atoms.Since their chemical formulas are different, "NaNO2" and "CaCO3" cannot be isomers. They are separate chemical compounds with different compositions and structures.To summarize, "NaNO2" and "CaCO3" are not isomers but rather different chemical compounds with distinct molecular formulas and crystal structures.
B. The two crystals, "NaNO2" (sodium nitrite) and "CaCO3" (calcium carbonate), are not polymorphs. They are different chemical compounds with distinct chemical compositions and crystal structures.Polymorphs are different crystal structures of the same chemical compound. In other words, polymorphs are different solid forms of a substance with the same chemical composition but different arrangements of atoms or molecules.In the case of "NaNO2" and "CaCO3," they have different chemical formulas and, therefore, cannot be polymorphs. "NaNO2" contains sodium, nitrogen, and oxygen atoms, while "CaCO3" contains calcium, carbon, and oxygen atoms. Additionally, they have different crystal structures due to their distinct arrangements of atoms.To be considered polymorphs, two substances must have the same chemical composition but different crystal structures. Since "NaNO2" and "CaCO3" do not fulfil this criterion, they are not polymorphs.
C. Sodium nitrate (NaNO3) and calcium carbonate (CaCO3) are not allotropes. They are two different chemical compounds with distinct molecular structures and compositions.Sodium nitrate (NaNO3) has a trigonal crystal system, meaning its crystal structure has threefold symmetry. It forms colourless, transparent crystals and is used n various applications, including fertilizers, food preservation, and pyrotechnics.Calcium carbonate (CaCO3) also belongs to the trigonal crystal system, with threefold symmetry in its crystal structure. It is a white, odourless solid found in nature as limestone, chalk, and marble. Calcium carbonate is widely used in construction, agriculture, and the manufacturing of various products like cement, paper, and plastics.In summary, sodium nitrate (NaNO3) and calcium carbonate (CaCO3) are different chemical compounds, and while they both possess a trigonal crystal system, they are not allotropes as they do not share the same chemical composition.
D. Sodium nitrite (NaNO2) and calcium carbonate (CaCO3) are not enantiomers. Enantiomers are a type of stereoisomer, meaning they are mirror images of each other. Enantiomers have the same chemical formula and connectivity of atoms, but their three-dimensional spatial arrangements differ. As a result, enantiomers exhibit optical activity, where they rotate plane-polarized light in opposite directions.In the case of sodium nitrite and calcium carbonate, they are different compounds with distinct chemical compositions and structures. Sodium nitrite is a nitrite salt, while calcium carbonate is a carbonate salt. They do not share the same chemical formula, and therefore, they cannot be enantiomers.In summary, sodium nitrite (NaNO2) and calcium carbonate (CaCO3) are not enantiomers. They are different chemical compounds with separate compositions and structures.
F. This is incorrect. A the guven compunds are isomorphs.

Q95. Nylon 4.6 is:

A. Addition polymer
B. Condensation polymer of hexandioic acid & 1,4 diaminobutane✓
C. It is an ester
D. Condensation polymer
E. It is a carboxylic acid

Explanation: The correct option is option B. Nylon 4,6 is a condensation polymer of hexanedioic acid (adipic acid) and 1,4-diamino butane. Therefore, the correct answer is option (b): Condensation polymer of hexanedioic acid and 1,4-diamino butane. Nylon 4,6 is a type of synthetic polymer that is formed through a condensation reaction between the carboxylic acid groups of hexanedioic acid and the amine groups of 1,4-diamino butane. This condensation reaction results in the formation of amide linkages, creating a long-chain polymer known as Nylon 4,6.

Why the other options are wrong

A. An "addition polymer" is a type of polymer formed through an addition polymerization process, where monomers add together without the elimination of any byproducts. Nylon 4.6 is not an addition polymer, so this option is not correct.
C. Nylon 4.6 is not an ester. Esters are a specific type of organic compound that result from the reaction between a carboxylic acid and an alcohol, leading to the formation of an ester linkage.
D. This option is similar to Option B, but it lacks specificity. Nylon 4.6 is indeed a condensation polymer, but the specific monomers involved are hexanedioic acid and 1,6-diaminohexane, as stated in Option B.
E. Nylon 4.6 is not a carboxylic acid. Carboxylic acids are a class of organic compounds that contain a carboxyl group (-COOH) attached to an alkyl or aryl group.

Q96. Ethene (H2C = CH2) has hybridization of C-atom:

A. dsp3
B. sp
C. sp3
D. dps3
E. sp2✓

Explanation: In an ethene molecule, the carbon atoms are sp2 hybridized. One unpaired electron in the p orbital remains unchanged. In ethylene, each carbon combines with three other atoms rather than four. So option E is correct.

Why the other options are wrong

A. This option represents hybridization involving d, s, and p orbitals. However, carbon does not commonly undergo dsp3 hybridization. Carbon typically undergoes sp, sp2, or sp3 hybridization in organic compounds.
B. This option represents sp hybridization, which is correct for the carbon atom in ethene. In ethene, the carbon atoms in the C=C double bond are sp hybridized. As explained earlier, each carbon atom forms two sigma bonds and one pi bond with the other carbon atom using sp hybrid orbitals.
C. This option represents sp3 hybridization, which is not correct for the carbon atom in ethene. Sp3 hybridization occurs when carbon forms four sigma bonds in a tetrahedral arrangement, but in ethene, the carbon atom forms only two sigma bonds due to the double bond.
D. This option appears to be a combination of dsp3 and sp3 hybridizations, which are not relevant to the carbon atom in ethene.

Q97. The kinetic molecular theory of gases explains:

A. Mass number
B. Atoms number
C. The behavior of gases✓
D. Electron
E. Neutron

Explanation: The kinetic molecular theory of gases explains the behaviour of gases, which is option C. The kinetic molecular theory of gases is a model that describes the behaviour of gases based on the motion of their individual particles.

Why the other options are wrong

A. The kinetic molecular theory of gases does not directly explain the concept of the mass number. The mass number refers to the sum of protons and neutrons in the nucleus of an atom and is relevant to the field of nuclear physics and atomic structure.
B. The kinetic molecular theory of gases does not directly explain the concept of the number of atoms. The behaviour of gases is explained based on the movement and interactions of individual molecules, not the number of atoms in a particular substance.
D. The kinetic molecular theory of gases does not directly involve the behaviour or explanation of electrons. The behaviour of electrons is primarily discussed in the context of atomic and molecular structures, not in the context of gas behaviour.
E. The kinetic molecular theory of gases does not directly involve the behaviour or explanation of neutrons. Neutrons are subatomic particles found in the nucleus of atoms and are not directly relevant to the theory that explains the behaviour of gases.

Q98. 2-chloropropane is heated with Na metal product is 2,3-dimethyl butane, reaction is:

A. Dehydrohalogenation
B. Wurtz reaction✓
C. Dehydration
D. Catalytic dehydrogenation
E. Dehalogenation

Explanation: The reaction you described, where 2-chloropropane is heated with Na metal to produce 2,3-dimethyl butane, is a Wurtz reaction. The Wurtz reaction is a coupling reaction in which alkyl halides are reacted with alkali metals, such as sodium (Na) or potassium (K), to form larger hydrocarbon molecules. In this specific case, the 2-chloropropane reacts with Na to form 2,3-dimethyl butane. Thus the correct option is option B.

Why the other options are wrong

A. Dehydrohalogenation is a reaction in which a halogen atom and a hydrogen atom are removed from adjacent carbon atoms, leading to the formation of a double bond. This reaction is not applicable to the conversion of 2-chloropropane to 2,3-dimethyl butane, as it involves the removal of both a hydrogen atom and a chlorine atom, resulting in a double bond.
C. Dehydration is a reaction in which water molecules are removed from a compound. This reaction is not relevant to the conversion of 2-chloropropane to 2,3-dimethyl butane since no water molecules are involved in the reaction.
D. Catalytic dehydrogenation is a reaction in which hydrogen atoms are removed from a compound in the presence of a catalyst. As with Option A, this reaction involves the removal of hydrogen atoms, which is not observed in the given reaction of 2-chloropropane to 2,3-dimethyl butane.
E. Dehalogenation is a reaction in which a halogen atom is removed from a compound. This reaction is the correct explanation for the conversion of 2-chloropropane to 2,3-dimethyl butane. The chlorine atom is removed from 2-chloropropane, resulting in the formation of 2,3-dimethyl butane.

Q99. At equilibrium in a reversible reaction:

A. The rate of forward > reaction rate of backward
B. The rate of backward reaction > rate of forward reaction
C. The rate of forward reaction is same as rate of backward reaction
D. The concentration of reactants & products becomes constant and rate of forward reaction is same as the rate of backward reaction✓
E. The concentration of reactant & products becomes constant

Explanation: At equilibrium in a reversible reaction: The concentration of reactants and products becomes constant, and the rate of the forward reaction is the same as the rate of the backward reaction, thus option D is correct.

Why the other options are wrong

A. This option suggests that at equilibrium, the forward reaction is occurring at a faster rate than the backward reaction. This cannot be true for a system at equilibrium because equilibrium is a dynamic state where the forward and backward reactions occur at the same rate, resulting in no net change in the concentrations of reactants and products.
B. This option also suggests an imbalance in the rates of the forward and backward reactions at equilibrium, which is incorrect. At equilibrium, the rates of both the forward and backward reactions are equal, ensuring a stable state with no overall change in concentrations.
E. This option is partially correct but lacks the crucial information that the rates of the forward and backward reactions are equal at equilibrium. Simply stating that the concentrations become constant does not fully capture the dynamic nature of equilibrium.

Q100. Rate of reaction increases by the addition of catalyst:

A. Catalyst reacts with reactant
B. Catalysts reacts with product
C. Energy of activation decreases✓
D. Energy of activation increases
E. Energy of activation

Explanation: Reaction rate increases by adding catalyst because it decreases activation energy, so Option C is the correct answer.

Why the other options are wrong

A. This option suggests that the catalyst directly participates in the reaction by reacting with the reactant. However, this is not the case for a catalyst. Catalysts work by providing an alternate reaction pathway with a lower activation energy without being consumed or permanently altered themselves.
B. Similar to Option A, this option also implies that the catalyst is involved in a chemical reaction with the product. Again, this is not how catalysts function. Catalysts facilitate reactions by lowering the activation energy, but they do not react with the product.
D. This option is not correct. A catalyst does not increase the energy of activation; it decreases it, as explained in Option C. An increased energy of activation would actually slow down the rate of the reaction, making this option incorrect.
E. This option does not provide any explanation but simply mentions the term "energy of activation," which is the energy barrier that reactant molecules must overcome to form products. As mentioned before, the catalyst reduces the energy of activation, leading to an increased reaction rate.

Q101. Reaction H2 + Cl2 -> 2HCl is:

A. Second order
B. First order
C. Half order
D. Third order
E. Zero order✓

Explanation: The correct answer is e) Zero order. The given reaction H2 + Cl2 -> 2HCl is a zero-order reaction, where the reaction rate is independent of the concentrations of the reactants.

Why the other options are wrong

A. The reaction is zero order reaction. The order of all photochemical reactions is zero as it does not depend upon the concentration of reactants. Hence this option is incorrect.
B. The reaction is zero order reaction. The order of all photochemical reactions is zero as it does not depend upon the concentration of reactants. Hence this option is incorrect.
C. The reaction is zero order reaction. The order of all photochemical reactions is zero as it does not depend upon the concentration of reactants. Hence this option is incorrect.
D. The reaction is zero order reaction. The order of all photochemical reactions is zero as it does not depend upon the concentration of reactants. Hence this option is incorrect.

Q102. The comparison of rate of diffusion of H2 & O2 is in the ratio of:

A. 2:1
B. 1:4
C. 3:2
D. 4:1✓
E. 1:2

Explanation: The comparison of rate of diffusion of H. & O2 is in the ratio of 4:1.

Why the other options are wrong

A. This is an incorrect comparision of rate of diffusion of H2 & O2.
B. This is an incorrect comparision of rate of diffusion of H2 & O2.
C. This is an incorrect comparision of rate of diffusion of H2 & O2.
E. This is an incorrect comparision of rate of diffusion of H2 & O2.

Q103. Grignard reagent, eg Methyl magnesium halide reacting with Methyl halide, the product is:

A. N-propyl chloride
B. Butane
C. Iso-propyl chloride
D. Methane
E. Ethane✓

Explanation: Grignard reagent, eg Methyl magnesium halide reacting with Methyl halide, product is ethane. Therefore option E is correct option.

Why the other options are wrong

A. Grignard reagent, eg Methyl magnesium halide reacting with Methyl halide, product is not n-propyl chloride.
B. Grignard reagent, eg Methyl magnesium halide reacting with Methyl halide, product is not butane.
C. Grignard reagent, eg Methyl magnesium halide reacting with Methyl halide, product is not iso-propyl chloride.
D. Grignard reagent, eg Methyl magnesium halide reacting with Methyl halide, product is not methane.

Q104. HOOC-COOH has IUPAC name:

A. Acetic acid
B. Oxalic acid
C. Diethanoic acid
D. Ethandioc acid✓
E. Benzoic acid

Explanation: The common name for the compound HOOC-COOH is oxalic acid. It is also iupac known as "ethanedioic acid".

Why the other options are wrong

A. This is not the correct IUPAC name of this structure.
B. This is the correct common name of this structure.
C. This is not the correct IUPAC name of this structure.
E. This is not the correct IUPAC name of this structure.

Q105. Pulverized CaCu3 reacts faster because of the increase in:

A. Pressure
B. Surface area✓
C. Volume
D. Surface tension
E. Temperature

Explanation: The correct answer is option B is the Surface area.In the case of pulverized CaCu3 (calcium carbide), the increased surface area provides more exposed sites for the reaction to occur. Therefore, the increase in surface area is the main factor that contributes to the faster reaction of pulverized CaCu3.

Why the other options are wrong

A. An increase in pressure typically affects reactions involving gases. However, in the context of the given question, which involves a solid reactant (pulverized CaCu3), pressure is unlikely to have a significant effect on the reaction rate. So, this option is not the correct explanation for why pulverized CaCu3 reacts faster.
C. The volume of a solid reactant is not a significant factor in determining the reaction rate in this context. The volume of a solid does not change upon pulverization, and volume is typically more relevant for reactions involving gases or liquids.
D. Surface tension is a property related to liquids and interfaces. It is not directly applicable to solid-solid reactions like the one described in the question. Therefore, this option is not the correct explanation.
E. While an increase in temperature generally leads to a faster reaction rate, it is not the reason why pulverized CaCu3 reacts faster. Temperature affects the rate of reaction by increasing the kinetic energy of the particles, making them move faster and collide more frequently. However, in the given context, the reaction rate is primarily influenced by the increase in surface area (Option B).

Q106. Oxidation of K2MnO4 by Cl2 is to manufacture:

A. K2CrO4
B. MnO2
C. K2Cr2O4
D. KMnO4✓
E. O2

Explanation: The correct answer is option D: KMnO4. When potassium permanganate (KMnO4) is oxidized by chlorine gas (Cl2), the product obtained is KMnO4 itself.

Why the other options are wrong

A. The oxidation of K2MnO4 by Cl2 does not result in the formation of K2CrO4 (Potassium Chromate). This option is incorrect.
B. The oxidation of K2MnO4 by Cl2 does not produce MnO2 as a product. This option is incorrect.
C. Similar to Option A, the oxidation of K2MnO4 does not lead to the formation of K2Cr2O4 (Potassium Dichromate). This option is incorrect.
E. As previously stated, the oxidation of K2MnO4 by Cl2 does not produce oxygen gas (O2) as a product. This option is incorrect.

Q107. Aldehyde reacts with:

A. Ketones are more easily oxidized
B. It is always difficult to oxidize aldehyde
C. Mild oxidizing agent & strong oxidizing agent both✓
D. Only strong oxidizing agent
E. Only mild oxidizing agent

Explanation: Aldehydes can react with both mild oxidizing agents and strong oxidizing agents.Aldehydes have a carbonyl group (C=O) where the carbon is bonded to at least one hydrogen atom. This hydrogen atom makes aldehydes more susceptible to oxidation compared to ketones, which have two carbon groups bonded to the carbonyl carbon. Therefore option C is the correct answer.

Why the other options are wrong

A. This option is incorrect. Ketones are generally more resistant to oxidation compared to aldehydes. Aldehydes have a hydrogen atom on their terminal carbon, which makes them more susceptible to oxidation compared to ketones, where the carbonyl group is situated between two carbon atoms.
B. This option is also incorrect. Aldehydes can be oxidized under suitable conditions. They are more easily oxidized compared to ketones, as mentioned earlier, but they still undergo oxidation reactions.
D. This option is incorrect. As mentioned in Option C, aldehydes can be oxidized by both strong and mild oxidizing agents. The use of strong oxidizing agents may result in overoxidation to carboxylic acids.
E. This option is also incorrect. While mild oxidizing agents may be used to selectively oxidize aldehydes to form corresponding carboxylic acids, they can also be used to form other products depending on the reaction conditions.

Q108. Benzene is subjected to alkylation nitration & oxidation the product is:

A. O & P nitro toluene
B. M-nitro benzoic acid
C. M-nitro toluene
D. O & P nitro benzoic acid✓
E. O nitro benzoic acid

Explanation: When benzene is subjected to alkylation, nitration, and oxidation, the product obtained is the option: o- and p-nitrobenzoic acid. Alkylation of benzene involves the substitution of an alkyl group (-R) onto the benzene ring, thus option D is the correct answer.

Why the other options are wrong

A. This option suggests that benzene is subjected to alkylation, nitration, and oxidation, and the product obtained is ortho and para nitro toluene. This product would be formed if benzene is first alkylated with a methyl group to form toluene, and then nitration occurs on the methyl group (methyl group is the substituent on benzene ring). However, the given question does not mention the alkylation of benzene to form toluene, so this option is not applicable.
B. This option suggests that benzene is subjected to nitration, and the product obtained is meta nitro benzoic acid. Nitration of benzene typically occurs at the ortho and para positions, but under certain conditions, it is possible to direct the nitration to the meta position. However, the given question mentions alkylation and oxidation in addition to nitration, so this option is not complete.
C. This option suggests that benzene is subjected to alkylation, nitration, and oxidation, and the product obtained is meta nitro toluene. This product would be formed if benzene is first alkylated with a methyl group to form toluene, and then nitration occurs on the benzene ring (not on the methyl group). The oxidation step could convert a methyl group to a carboxylic acid group (not mentioned in the question). Since the oxidation step is not clearly defined in the question, we cannot say for certain that this is the correct option.
E. This option suggests that benzene is subjected to nitration and oxidation, and the product obtained is ortho nitro benzoic acid. Nitration of benzene typically results in the formation of ortho and para nitro derivatives. The oxidation step could convert a methyl group to a carboxylic acid group (not mentioned in the question). Since the alkylation step is not mentioned in the question, we cannot say for certain that this is the correct option.

Q109. In Castner Kellner cell:

A. NaOH+ H2 are produced at cathode
B. Cl2 is produced at anode
C. NaOH+H2 are produced at anode
D. NaOH+H2 are produced at cathod and Cl2 is produced at anode✓
E. Cl2 is produced at cathode

Explanation: In the Castner-Kellner cell, option (d) is correct: NaOH + H2 is produced at the cathode, and Cl2 is produced at the anode. The Castner-Kellner cell is an electrolytic cell used for the production of sodium hydroxide (NaOH) and chlorine gas (Cl2) through the electrolysis of brine (sodium chloride solution). So option D is the correct answer.

Why the other options are wrong

A. This option is incorrect because at the cathode, only hydrogen gas (H2) is produced during electrolysis. Sodium hydroxide (NaOH) is produced at the anode.
B. This option is incorrect because at the anode, chlorine gas (Cl2) is not produced. Instead, sodium hydroxide (NaOH) is produced at the anode.
C. This option is incorrect because at the anode, sodium hydroxide (NaOH) is produced, but hydrogen gas (H2) is not produced.
E. This option is incorrect because chlorine gas (Cl2) is not produced at the cathode. It is produced at the anode.

Q110. Bakelite is polymer of:

A. Two glucose molecules
B. Formaldehyde & acetone
C. Two amino acid molecule
D. Formaldehyde & phenol✓
E. Acetone & carboxylic acid

Explanation: Bakelite is a polymer of phenol and formaldehyde. Bakelite, also known as polyoxybenzylmethylenglycolanhydride, is one of the first synthetic polymers to be commercially produced. Therefore option D is the correct answer.

Why the other options are wrong

A. This option is incorrect. Bakelite is not formed from glucose molecules. It is a synthetic polymer, not a natural one like cellulose (which is composed of glucose molecules).
B. This option is incorrect. Bakelite is formed from formaldehyde and phenol, not formaldehyde and acetone.
C. This option is incorrect. Bakelite is not formed from amino acid molecules. Amino acids are the building blocks of proteins, not polymers like Bakelite.
E. This option is incorrect. Bakelite is not formed from acetone and carboxylic acid. It is formed from formaldehyde and phenol, as explained in option D.

Q111. Phenol when subjected to nitration product is:

A. o-nitro phenol
B. p-nitro phenol
C. o-nitro phenol & m - nitro phenol
D. o-nitro phenol & p-nitro phenol✓
E. m-nitro phenol

Explanation: Phenol, when subjected to nitration, produces option o-nitrophenol and p-nitrophenol. Nitration of phenol involves the substitution of a nitro group (-NO2) onto the phenol ring. The nitro group can substitute either at the ortho (o), meta (m), or para (p) positions relative to the hydroxyl group (-OH) of phenol. Thus option D is the correct answer.

Why the other options are wrong

A. This option suggests that only o-nitro phenol is produced during the nitration of phenol. In this case, the nitro group is attached to the ortho position of the phenol ring. Hence the wrong option.
B. This option suggests that only p-nitro phenol is produced during the nitration of phenol. In this case, the nitro group is attached to the para position of the phenol ring. Hence the wrong option.
C. This option suggests that both o-nitro phenol and m-nitro phenol are produced during the nitration of phenol. In this case, the nitro group is attached to both the ortho and meta positions of the phenol ring. Hence the wrong option.
E. This option suggests that only m-nitro phenol is produced during the nitration of phenol. In this case, the nitro group is attached to the meta position of the phenol ring. Hence the wrong option.

Q112. Heating a mixture of chromite are (FeOCr2O3) & K2CO3 in air is to manufacture:

A. K2MnO4
B. K2Cr2O7
C. KMnO4
D. Kl
E. K2CrO4✓

Explanation: Heating a mixture of chromite (FeCr2O4) and K2CO3 (not KCO3 as mentioned in the question) in air is done to manufacture option (e): K2CrO4, also known as potassium chromate.The reaction that occurs during this process is as follows:4 FeCr2O4 + 8 K2CO3 + 7 O2 → 8 K2CrO4 + 2 Fe2O3 + 8 CO2Therefore, the correct answer is option E: K2CrO4.

Why the other options are wrong

A. K2MnO4 is not produced by heating a mixture of chromite (FeOCr2O3) and K2CO3 in air.
B. K2Cr2O7 is not produced by heating a mixture of chromite (FeOCr2O3) and K2CO3 in air.
C. KMnO4 is not produced by heating a mixture of chromite (FeOCr2O3) and K2CO3 in air.
D. Kl (potassium iodide) is not produced by heating a mixture of chromite (FeOCr2O3) and K2CO3 in air.

Q113. A strong electrolyte is one that, _ completely in solution.

A. Reacts
B. Decomposes
C. Disappears
D. Ionizes✓
E. Never ionizes

Explanation: They completely ionizes into the solution. So option D is correct.

Why the other options are wrong

A. This is not the correct word to be used here.
B. This is not the correct word to be used here.
C. This is not the correct word to be used here.
E. This is not the correct word to be used here.

Q114. Cation & anion formed which combines to form crystal lattices:

A. Only cation is isoelectronic to nearest noble gas
B. Cation & anion both are isoelectronic to hearest noble gas
C. Cation & union both are isoelectronic to nearest noble gas de No of electron lost by metal a no of electron gained by non metal are equal✓
D. Only anion is isoelectronic to nearest noble gas
E. No of electron lost by metal & no of electron gained by non metal are equal

Explanation: The correct answer is option C: Cation and anion both are isoelectronic to the nearest noble gas, and the number of electrons lost by the metal is equal to the number of electrons gained by the non-metal. In crystal lattices, cations (positively charged ions) and anions (negatively charged ions) combine to form a stable structure. The cations and anions are attracted to each other due to electrostatic forces.

Why the other options are wrong

A. This option suggests that only the cation (positively charged ion) formed in the crystal lattice is isoelectronic to the nearest noble gas. Isoelectronic species have the same number of electrons as the noble gas. The anion (negatively charged ion) is not mentioned to be isoelectronic.
B. This option suggests that both the cation and anion formed in the crystal lattice are isoelectronic to the nearest noble gas. Both species have the same number of electrons as the noble gas.
D. This option suggests that only the anion formed in the crystal lattice is isoelectronic to the nearest noble gas. The cation is not mentioned to be isoelectronic.
E. This option does not mention anything about isoelectronic species but states that the number of electrons lost by the metal (cation) is equal to the number of electrons gained by the non-metal (anion), ensuring the overall charge neutrality of the crystal lattice.

Q115. Secondary alcohols have:

A. One βC
B. Three βC
C. No βC
D. Two βC✓
E. Four βC

Explanation: Secondary alcohols have option (d): Two beta carbons (BC). In organic chemistry, the term "beta carbon" (BC) refers to the carbon atom adjacent to a functional group. In the case of secondary alcohols, the functional group is the hydroxyl group (-OH) attached to a carbon atom that is bonded to two other carbon atoms.

Why the other options are wrong

A. In this option, it is stated that only the cation (positively charged ion) formed in the crystal lattice is isoelectronic to the nearest noble gas. The anion (negatively charged ion) may or may not be isoelectronic
B. This option suggests that both the cation and the anion formed in the crystal lattice are isoelectronic to the nearest noble gas. Both species have the same number of electrons as the nearest noble gas.
C. In this option, it is specified that both the cation and the anion are isoelectronic to the nearest noble gas. Additionally, it is mentioned that the number of electrons lost by the metal (cation) is equal to the number of electrons gained by the non-metal (anion), ensuring that the overall charge of the crystal lattice remains neutral.
E. This option does not mention anything about isoelectronic species but states that the number of electrons lost by the metal (cation) is equal to the number of electrons gained by the non-metal (anion), ensuring the overall charge neutrality of the crystal lattice.

Q116. Small diffusion in solid is due to:

A. Very fast motion of its particle
B. Vibrational motions of its particle✓
C. Rotational motion of its particle
D. Translational motion of its particle
E. Diffusion into solid is not present

Explanation: Small diffusion in a solid is due to option B: Vibrational motions of its particles. In a solid, the particles (atoms, ions, or molecules) are closely packed and held in a fixed position by strong intermolecular or interatomic forces.

Why the other options are wrong

A. This option suggests that small diffusion in solids is due to the very fast motion of the particles. However, in solids, the particles do not have free movement like in gases or liquids, so this option is not accurate.
C. This option implies that small diffusion in solids is due to the rotational motion of its particles. However, in most cases, particles in solids do not have significant rotational motion, so this option is not valid.
D. This option states that small diffusion in solids is due to the translational motion of its particles. In solids, particles do not have translational motion as they are held in fixed positions. Therefore, this option is not accurate.
E. This option suggests that there is no diffusion into the solid. However, small diffusion can still occur in solids due to the vibrational motions of its particles, as explained in Option B.

Q117. Gases deviate from ideal behavior more:

A. Gases do not deviate from ideal behavior
B. Both temperature & pressure low
C. Both temperature & pressure high
D. At high pressure & low temperature✓
E. At low pressure & high temperature

Explanation: Gases deviate from ideal behaviour more at high pressure and low temperature, which is an option (D). At high pressures, gas particles are closer together and experience stronger intermolecular forces, leading to deviations from ideal behaviour. Additionally, at low temperatures, gas particles have lower kinetic energy, resulting in decreased molecular motion and increased attractive forces between particles. Both of these factors contribute to greater deviations from ideal gas behavior.

Why the other options are wrong

A. This option states that gases do not deviate from ideal behavior, which is not true. In reality, all gases deviate from ideal behavior to some extent, especially at certain conditions.
B. This option suggests that gases deviate from ideal behavior more when both temperature and pressure are low. At low temperatures and pressures, the volume of gas molecules becomes significant compared to the space between them, leading to deviations from ideal behavior.
C. This option proposes that gases deviate from ideal behavior more when both temperature and pressure are high. At high temperatures and pressures, the attractive forces between gas molecules become more significant, causing deviations from ideal behavior.
E. This option states that gases deviate from ideal behavior more at low pressure and high temperature. However, at low pressures and high temperatures, the gas molecules are more widely spaced, and their attractive forces are weaker, leading to gas behavior that is closer to ideal.

Q118. 3.0g of C on combustion gives:C+O ->CO2:

A. 5.5 g of CO2
B. 22 g of CO2
C. 6.02 x 10 molecules of CO2
D. 3.01 x 10 molecules CO2
E. 1.505 X 10^23 molecule of CO2✓

Explanation: 3.0g of C on combustion gives 1.505 X 10^23 molecule of CO2. As it is a numerical only one option E is correct.

Why the other options are wrong

A. This option suggests that 3.0 g of carbon (C) on combustion produces 5.5 g of carbon dioxide (CO2). However, this is not correct because the molar mass of CO2 is 44 g/mol, and 3.0 g of carbon would produce less than 5.5 g of CO2.
B. This option suggests that 3.0 g of carbon (C) on combustion produces 22 g of carbon dioxide (CO2). However, this is not correct because the molar mass of CO2 is 44 g/mol, and 3.0 g of carbon would produce less than 22 g of CO2.
C. This option suggests that 3.0 g of carbon (C) on combustion produces 6.02 x 10^23 molecules of carbon dioxide (CO2). This is not correct because it represents Avogadro's number (6.02 x 10^23), which is the number of molecules in one mole of a substance. It does not directly relate to the amount of CO2 produced by the combustion of 3.0 g of carbon.
D. This option suggests that 3.0 g of carbon (C) on combustion produces 3.01 x 10^23 molecules of carbon dioxide (CO2). Similar to Option C, this is not correct because it does not provide a valid calculation or reasoning for the amount of CO2 produced.

Q119. Alkyl halide, on reaction with NaOH, produces an alcohol. What are the mechanics of reaction?

A. SN✓
B. Elimination
C. Decomposition
D. Electrophilic substitution reaction
E. Addition

Explanation: Alkyl halide, in reaction with NaOH, the product is an alcohol. The mechanics of the reaction is SN.This reaction proceeds by a nucleophilic substitution (SN) mechanism, which may be SN1 or SN2 depending on the structure of the alkyl halide. The correct answer is option A.

Why the other options are wrong

B. Alkyl halide, on reaction with NaOH, product is an alkane. Mechanics of reaction is not elimination.
C. Alkyl halide, on reaction with NaOH, product is an alkane. Mechanics of reaction is not decomposition.
D. Alkyl halide, on reaction with NaOH, product is an alkane. Mechanics of reaction is not electrophilic substitution reaction.
E. Alkyl halide, on reaction with NaOH, product is an alkane. Mechanics of reaction is not addition.

Q120. The first organic compound manufactured from inorganic compound is:

A. Ethyl acetate
B. Urea✓
C. Acetic acid
D. Methane
E. Acetone

Explanation: The correct answer is option (B): Urea.Urea is the first organic compound that was successfully synthesized from an inorganic compound.

Why the other options are wrong

A. This is not the first organic compound manufactured from inorganic compound.
C. This is not the first organic compound manufactured from inorganic compound.
D. This is not the first organic compound manufactured from inorganic compound.
E. This is not the first organic compound manufactured from inorganic compound.

Q121. The ionization energy increases along a period in periodic table due to increase in:

A. No. of positron
B. No. of neutron
C. Nuclear charge✓
D. No. of electron
E. Atomic size

Explanation: The correct answer is option (c): Nuclear charge. Ionization energy is the energy required to remove an electron from an atom or ion in its gaseous state. Along a period in the periodic table, the ionization energy generally increases. This increase is primarily due to an increase in the nuclear charge or the number of protons in the nucleus of the atoms.

Why the other options are wrong

A. This option suggests that the ionization energy increases along a period in the periodic table due to an increase in the number of positrons. However, this is not correct because positrons are positively charged particles that are found in antimatter and are not relevant to the ionization energy of elements.
B. This option suggests that the ionization energy increases along a period in the periodic table due to an increase in the number of neutrons. However, this is not correct because the ionization energy primarily depends on the nuclear charge (protons) and the effective nuclear charge experienced by the valence electrons, not the number of neutrons.
D. This option suggests that the ionization energy increases along a period in the periodic table due to an increase in the number of electrons. However, this is not correct because the ionization energy depends on the nuclear charge and effective nuclear charge, not the total number of electrons.
E. This option suggests that the ionization energy increases along a period in the periodic table due to a decrease in atomic size. However, this is not correct because ionization energy generally increases as we move from left to right across a period, and atomic size decreases. The increase in ionization energy is primarily due to the increase in nuclear charge and the stronger attraction between the valence electrons and the nucleus.

Q122. Reaction taking place in one step or in several steps have same ΔH. it is:

A. Lussac's law of combining volume
B. Hess's law✓
C. Boyle's law
D. Charle's law
E. Avagadro's law

Explanation: Hess's law states that the enthalpy change of a reaction is independent of the pathway taken from reactants to products. In other words, the total enthalpy change of a reaction is determined only by the initial and final states of the reaction, regardless of whether the reaction occurs in one step or multiple steps.

Why the other options are wrong

A. Lussac's law of combining volumes is related to the volumes of gases involved in chemical reactions. It states that when gases react with each other, the volumes of the reacting gases and the volumes of the gaseous products, if all volumes are measured at the same temperature and pressure, are in simple whole number ratios. This law is not related to the enthalpy change (ΔH) of a reaction.
C. Boyle's law relates the pressure and volume of a gas at a constant temperature. It states that the pressure of a gas is inversely proportional to its volume when temperature is held constant. Boyle's law is not related to the enthalpy change of a reaction.
D. Charles's law relates the volume and temperature of a gas at constant pressure. It states that the volume of a gas is directly proportional to its absolute temperature when pressure is constant. Charles's law is not related to the enthalpy change of a reaction.
E. Avogadro's law relates the volume and amount (moles) of a gas at constant temperature and pressure. It states that equal volumes of gases at the same temperature and pressure contain an equal number of molecules. Avogadro's law is not related to the enthalpy change of a reaction.

Q123. Oxidation of a primary alcohol with PCC (Pyridiniumchlorochromate) gives a/an:

A. Aldehyde✓
B. Ketone
C. Carboxylic acid
D. Ester

Explanation: PCC is a mild oxidizing agent that is selective for the oxidation of primary alcohols. It converts them to aldehydes and is not strong enough to oxidize them further to carboxylic acids.

Why the other options are wrong

B. Ketones are formed by the oxidation of secondary alcohols, not primary alcohols. Therefore, this option is incorrect in the context of primary alcohol oxidation.
C. Carboxylic acids can be formed by the further oxidation of aldehydes, but this is not the product of oxidizing primary alcohols with PCC.
D. Esters are not formed directly from the oxidation of alcohols. They result from the reaction of carboxylic acids with alcohols, making this option incorrect.

Q124. Primary alcohol when react with a halogen acid, the product is:

A. Secondary alcohol
B. Tertiary alcohol
C. Primary alcohol
D. Primary alkyl halide✓
E. Secondary alkyl halide

Explanation: When primary alcohol reacts with a halogen acid, the product formed is option (D): Primary alkyl halide.The reaction between a primary alcohol and a halogen acid, such as hydrochloric acid (HCl) or hydrobromic acid (HBr), undergoes a substitution reaction called nucleophilic substitution. In this reaction, the halogen replaces the hydroxyl group of the alcohol.The reaction can be represented as follows:Primary Alcohol + Halogen Acid → Primary Alkyl Halide + Water

Why the other options are wrong

A. When a primary alcohol reacts with a halogen acid (such as HCl, HBr, or HI), it typically undergoes a substitution reaction, and the product formed is a secondary alkyl halide. The -OH group of the primary alcohol is replaced by the halogen (X) atom, resulting in the formation of the secondary alkyl halide.
B. A primary alcohol does not directly form a tertiary alcohol when reacting with a halogen acid. Tertiary alcohols have three alkyl groups (R) attached to the carbon with the -OH group, and they are not typically formed through halogen acid reactions with primary alcohols.
C. A primary alcohol reacting with a halogen acid would not result in the formation of a primary alcohol. The original primary alcohol is a reactant, not a product, in this reaction.
E. A secondary alcohol, not a primary alcohol, would form a secondary alkyl halide when reacting with a halogen acid. In a secondary alkyl halide, the carbon with the halogen attached is bonded to two alkyl groups (R), and it is formed by the substitution of the -OH group in a secondary alcohol.

Q125. Acetophenone is an:

A. Aliphatic ketones
B. Phenol
C. Carboxylic acid
D. Aldehyde
E. Aromatic ketones✓

Explanation: This is the correct option. Acetophenone is an aromatic ketone. It consists of a phenyl group (aromatic ring) attached to a carbonyl group (ketone functional group). The aromatic ring in acetophenone gives it its aromatic character and the carbonyl group makes it a ketone.

Why the other options are wrong

A. It is not an aliphatic ketone.
B. It is not a Phenol.
C. It is not a Carboxylic acid.
D. It is not an Aldehyde.

Q126. SN1 mechanism is a:

A. Formation of carbocation is fast step
B. Single step mechanism
C. Two step mechanism mechanism✓
D. Attack of nucleophile an carbocation is slow step
E. Primary alkyl halide follow

Explanation: The correct answer is option (C): Two-step mechanism.The SN1 mechanism, also known as the substitution nucleophilic unimolecular mechanism, is a two-step mechanism.

Why the other options are wrong

A. This statement is incorrect. In the SN1 mechanism, the formation of the carbocation intermediate is the slow step.
B. This statement is incorrect. The SN1 mechanism is not a single-step mechanism. It is a two-step process: the formation of a carbocation intermediate in the first step and the attack of a nucleophile on the carbocation in the second step.
D. This statement is partially correct. In the SN1 mechanism, the attack of the nucleophile on the carbocation is indeed a slow step. Carbocations are unstable intermediates and form quickly, but their reactivity is relatively low. As a result, the rate-determining step is usually the nucleophilic attack on the carbocation, which is a slower process.
E. This statement is also partially correct. Primary alkyl halides are more likely to undergo SN2 (Substitution Nucleophilic Bimolecular) reactions rather than SN1 reactions. In SN2 reactions, the nucleophile directly displaces the leaving group in a single concerted step. Primary alkyl halides are more favorable for SN2 reactions because they have less steric hindrance, which allows the nucleophile to attack from the backside of the carbon more easily. SN1 reactions are more commonly observed with tertiary alkyl halides where the carbocation can be stabilized by neighboring alkyl groups.

Q127. Hexanoic acid is IUPAC name:

A. Adipic acid
B. Propionic acid
C. Formic acid
D. Caproic acid✓
E. Butyric acid

Explanation: As mentioned in STB, the IUPAC name is Caproic acid. So option D is correct answer.

Why the other options are wrong

A. It is not an IUPAC name of Hexanoic acid.
B. It is not an IUPAC name of Hexanoic acid.
C. It is not an IUPAC name of Hexanoic acid.
E. It is not an IUPAC name of Hexanoic acid.

Q128. The option having all the properties of gamma rays:

A. Neutron highly penetrating, velocity is equal to that of light. Remain un deflected in magnetic field
B. Most penetrating, velocity is equal to that of light no deflection in magnetic field, short wave length, shorter than x-rays✓
C. Least penetrating, velocity /o of light deflects in magnetic field helium nucleus
D. Proton least penetrating, deflects like negative particle in magnetic field
E. Most penetrating power, velocity less than that light of deflects in magnetic filed they are Electron

Explanation: Most penetrating, velocity is equal to that of light, no deflection in a magnetic field, short wavelength, shorter than x-rays. So option B is the correct answer for this question.

Why the other options are wrong

A. This option is incorrect. Gamma radiations are not neutrons but photons of light.
C. That's incorrect. These are properties of alpha particle radiations.
D. This option is incorrect. These are not properties of gamma radiations but beta particles.
E. That's incorrect. These are not the properties of gamma radiations. These radiations have speed equal to speed of light.

Q129. The solubility product Ksp predicts whether:

A. Diffusion
B. Solubility
C. Precipitation will take place or not✓
D. Boiling point
E. Melting point

Explanation: The solubility product constant, represented as Ksp, is an equilibrium constant specific to the dissolution of a sparingly soluble salt in water. It quantitatively expresses the solubility of a compound and predicts whether precipitation will occur when the solution is saturated. So option C is the correct answer.

Why the other options are wrong

A. This option is incorrect. Ksp does not explain diffusion; it explains solubility or predicts while precipitation will take place or not.
B. This option is incorrect.
D. This option is incorrect. Ksp does not explain boiling point; it explains solubility or predicts while precipitation will take place or not .
E. This option is incorrect. Ksp does not explain melting point; it explains solubility or predicts while precipitation will take place or not .

Q130. In protein, amino acid molecules are linked by:

A. Glucosidic linkage
B. Glycosidic linkage
C. Peptide linkage✓
D. Ethane linkage
E. Ester linkage

Explanation: Protein structure, amino acids are linked by peptide bonds, formed between a carboxylic acid molecule of one amino acid and the amino group of another amino acid.

Why the other options are wrong

A. No such linkage exists.
B. This linkage is present between carbohydrate molecules.
D. No such linkage exists.
E. The bond formed between two organic molecules.

Q131. Ratio of atomic mass of hydrogen to atomic mass of C is:

A. One sixth
B. One twelfth✓
C. Half
D. Double
E. Equal

Explanation: The ratio of the atomic mass of hydrogen to the atomic mass of C is one-twelfth. So option B is the correct answer.

Why the other options are wrong

A. This is the incorrect ratio.
C. This is the incorrect ratio.
D. This is the incorrect ratio.
E. This is the incorrect ratio.

Q132. Reforming:

A. Increases knocking of internal combustion engine
B. Increases the octane number✓
C. More is the knocking the better is the fuel
D. To produce a fuel of less octane number

Explanation: Reforming is a process used in the petroleum industry to increase the octane number of gasoline. Octane number is a measure of a fuel's resistance to knocking in internal combustion engines.

Why the other options are wrong

A. This option is incorrect because increasing knocking indicates poor fuel quality, which is the opposite of what reforming aims to achieve.
C. This option is incorrect because knocking is detrimental to engine performance and fuel quality; better fuels have lower knocking tendencies.
D. This option is incorrect as it contradicts the aim of reforming, which is to increase the octane number, not decrease it.

Q133. Addition product of formaldehyde & ethyl alcohol is:

A. Aldehyde
B. Acetal✓
C. Carboxylic acid
D. Acetone
E. Ketone

Explanation: The addition product of formaldehyde and ethyl alcohol is option (b): Acetal.When formaldehyde (HCHO) reacts with ethyl alcohol (C2H5OH) in the presence of an acid catalyst, an acetal is formed.The reaction can be represented as follows:HCHO + 2C2H5OH → CH(OC2H5)3The resulting compound CH(OC2H5)3 is an acetal, which is a type of organic compound.

Why the other options are wrong

A. It is not the addition product of formaldehyde & ethyl alcohol.
C. It is not the addition product of formaldehyde & ethyl alcohol.
D. It is not the addition product of formaldehyde & ethyl alcohol.
E. It is not the addition product of formaldehyde & ethyl alcohol.

Q134. Down cell is for the:

A. Metallurgy of Na✓
B. Metallurgy of Mg
C. Metallurgy of Al
D. Metallurgy of Fe
E. Metallurgy of ca

Explanation: The Down's cell is used for the metallurgy of sodium (Na).In the metallurgy of sodium, the Down's cell is an electrolytic cell that is utilized for the production of sodium metal through the electrolysis of molten sodium chloride (NaCl). Thus option A is the correct answer.

Why the other options are wrong

B. This option is incorrect .The Downs cell is an industrial electrochemical cell used to produce metallic sodium and chlorine gas from molten sodium chloride (NaCl).
C. This option is incorrect .The Downs cell is an industrial electrochemical cell used to produce metallic sodium and chlorine gas from molten sodium chloride (NaCl).
D. This option is incorrect .The Downs cell is an industrial electrochemical cell used to produce metallic sodium and chlorine gas from molten sodium chloride (NaCl).
E. This option is incorrect .The Downs cell is an industrial electrochemical cell used to produce metallic sodium and chlorine gas from molten sodium chloride (NaCl).

Q135. Falling drop of liquid is spherical due to its:

A. Evaporation on exposure
B. Surface tension✓
C. Atomic structure
D. Viscosity
E. Vapor pressure

Explanation: The correct answer is option (b): Surface tension.When a drop of liquid falls freely, it tends to form a spherical shape. This is due to the property of surface tension. Surface tension is the force that acts at the surface of a liquid and tends to minimize its surface area.

Why the other options are wrong

A. Evaporation is a process in which a liquid changes to a gaseous state due to heating or exposure to environmental conditions. While evaporation can affect the size of a liquid droplet, it is not the primary reason for its spherical shape.
C. The atomic structure of a liquid does influence its properties, including surface tension, but the spherical shape of a falling liquid droplet is mainly a result of surface tension forces.
D. Viscosity is a measure of a fluid's resistance to flow. It does not directly determine the shape of a liquid droplet, but it can influence how the droplet interacts with the surrounding environment.
E. Vapor pressure is the pressure exerted by the vapor molecules above the liquid in a closed container. While it is related to the evaporation process, it does not determine the spherical shape of a falling liquid droplet.

Q136. Catalytic hydrogenation of oil gives:

A. Alkene
B. Alkyne
C. Soap
D. Alkyl halides
E. Fats✓

Explanation: The correct answer is option Fat, Option E. The catalytic hydrogenation of oil refers to the process of adding hydrogen (H2) in the presence of a catalyst to unsaturated fats or oils. This process converts unsaturated fatty acids, which have double bonds, into saturated fatty acids by adding hydrogen atoms.

Why the other options are wrong

A. This option is not correct as hydrogenation doesn't gives unsaturated hydrocarbons like alkenes .
B. This option is not correct as hydrogenation doesn't gives unsaturated hydrocarbons like alkynes .
C. This option is incorrect. Catalytic hydrogenation produces fats, while soaps are the products of saponification.
D. This option is not correct.

Q137. Benzyl alcohol C6H5CH2OH is a:

A. Aromatic alcohol✓
B. Phenol
C. Aromatic ketone
D. Aliphatic alcohol
E. Alicyclic alcohol

Explanation: Benzyl alcohol C6H5CH2OH is an aromatic alcohol. The presence of the benzene ring classifies it as an aromatic compound, and the presence of the hydroxyl group makes it an alcohol. Thus option A is correct.

Why the other options are wrong

B. This option is not correct as phenol has only alcohol group.
C. This option is not correct.
D. This option is not correct.
E. This option is not correct.

Q138. Ammonia Solvay process is an industry for manufacture of:

A. HNO3
B. HCL
C. Soda ash Na2CO3✓
D. H2SO3
E. CaCO2

Explanation: The correct answer is option (c): Soda Ash (Na2CO3).The Solvay process is an industrial method for the production of sodium carbonate, commonly known as soda ash. In this process, ammonia (NH3) and carbon dioxide (CO2) are used to produce sodium carbonate by a series of chemical reactions.

Why the other options are wrong

A. This option is not correct as HNO3 is not formed during the whole Solvay process.
B. This option is not correct as HCL is not formed during the whole Solvay process.
D. This option is not correct as H2SO3 is not formed during the whole Solvay process.
E. This option is not correct as CaCO2 is not formed during the whole Solvay process.

Q139. The quantum number allows following orbitals in M shell:

A. s-orbital
B. s, p, d& f orbital
C. s & p orbital
D. All options are correct
E. s ,p & d orbital✓

Explanation: The possible orbitals are the s, p, and d orbitals. The s orbital is spherical in shape, while the p orbitals are dumbbell-shaped and can be oriented along the x, y, and z axes. The d orbitals have more complex shapes and orientations. Therefore, in the M shell, the allowed orbitals are the s,p and d orbitals. So option E is correct.

Why the other options are wrong

A. This option is incorrect because the M shell has three orbitals: s, p, and d orbitals.
B. This option is incorrect because the M shell has three orbitals: s, p, and d orbitals.
C. This option is incorrect because the M shell has three orbitals: s, p, and d orbitals.
D. This option is incorrect as only correct option is E.

Q140. Exothermic reaction, by decreasing the temperature, equilibrium constant:

A. Same
B. Sometimes decreases sometimes increases
C. Reaction moves backward
D. Decreases
E. Increases✓

Explanation: In exothermic reactions Kc is inversely proportional to temperature it mean when temperature will increase Kc will decrease and when temperature increases Kc decreases.

Why the other options are wrong

A. This option suggests that the equilibrium constant remains unchanged when the temperature of an exothermic reaction is decreased. However, this is not accurate. The equilibrium constant of a reaction is influenced by temperature changes, especially in the case of exothermic reactions where heat is a product.
B. This option suggests that the effect of decreasing the temperature on the equilibrium constant can vary depending on the specific reaction. While temperature changes can indeed have different effects on equilibrium constants, in the context of exothermic reactions, decreasing the temperature generally leads to a decrease in the equilibrium constant due to the reasons explained earlier.
C. Decreasing the temperature in an exothermic reaction causes the equilibrium to shift towards the reactants to counteract the heat loss. This shift is often interpreted as the reaction moving backward because more reactants are being formed. So, this option is partially correct in describing the shift of the equilibrium position
D. In an exothermic reaction, heat is released as a product. The equilibrium constant (Kc) for a chemical reaction is a measure of the ratio of products to reactants at equilibrium. It depends on temperature according to the principle of Le Chatelier.When the temperature is decreased in an exothermic reaction, the system responds by shifting the equilibrium position to counteract the change. In this case, the system will try to replace the heat that was removed. Since heat is a product of an exothermic reaction, decreasing the temperature will shift the equilibrium towards the side of the reactants, in an attempt to produce more heat. As a result, the concentration of products decreases, and the equilibrium constant (Kc) will decrease.

Q141. The angular momentum of a partcile changes from 0 to 720J.s in 4s. The magnitude of torque is:

A. 2880 N-m
B. 180 N-m✓
C. 360 Nm
D. 1440 Nm
E. 90 Nm

Explanation: L = Iω, In this case, the angular momentum changes from 0 to 720 J·s, and the time taken is 4 seconds. We can calculate the average angular momentum using the formula: L_avg = ΔL / Δt, where ΔL is the change in angular momentum and Δt is the change in time. Substituting the given values: L_avg = (720 J·s - 0) / 4 s = 180 J·s/s. Now, we know that torque (τ) is related to the rate of change of angular momentum by the equation: τ = dL / dt, where dL is the differential change in angular momentum and dt is the differential change in time. Since we have the average angular momentum, we can rewrite the equation as: τ = dL_avg / dt. Substituting the values: τ = 180 J·s/s / 1 s = 180 N·m. Therefore, the magnitude of torque is 180 N·m As it is a numerical only one option B is correct.

Why the other options are wrong

A. This option is not correct as per calculations.
C. This option is not correct as per calculations.
D. This option is not correct as per calculations.
E. This option is not correct as per calculations.

Q142. An object moving faster than the speed of sound. This object is called:

A. Sonic
B. Supersonic✓
C. Hypersonic
D. Ultrasonic
E. infrasonic

Explanation: When an object is moving faster than the speed of sound in a medium, it is considered supersonic. The speed of sound varies depending on the medium, but in the air at sea level, it is approximately 343 meters per second. If an object exceeds this speed, it is said to be supersonic. So option B is correct.

Why the other options are wrong

C. Hypersonic refers to speeds significantly higher than the speed of sound.
D. Ultrasonic refers to frequencies or waves that are beyond the range of human hearing, typically above 20,000 Hertz.
E. Infrasonic refers to frequencies or waves that are below the range of human hearing, typically below 20 Hertz.

Q143. If a slab of dielectric constant Er=2 is inserted between, the parallel plates of a charged 20 uF capacitor. Its capacitance will:

A. Remain the same
B. Be four times
C. Be doubled✓
D. Be halved
E. Become zero

Explanation: The capacitance will be doubled when the dielectric slab is inserted. So option C is correct.

Why the other options are wrong

A. This option is not correct as capacitance increases when the dielectric is placed between plates of capacitor.
B. This option is incorrect as per calculations.
D. This option is not correct as capacitance increases when the dielectric is placed between plates of capacitor.
E. This option is not correct as capacitance increases when the dielectric is placed between plates of capacitor.

Q144. When different resistors are connected across terminals of battery:

A. Both emf and terminal potential difference gradually changes
B. Both emf and terminal potential difference changes
C. Its emf changed but terminal potential difference remains same
D. Both emf and terminal potential difference remains same
E. Its emf remains same but terminal potential difference changes✓

Explanation: When different resistors are connected across terminals of battery their emf remains same but terminal potential difference changes. So option E is correct.

Why the other options are wrong

A. This option is incorrect as only terminal potential difference changes while emf remains same.
B. This option is incorrect as only terminal potential difference changes while emf remains same
C. This option is incorrect as only terminal potential difference changes while emf remains same
D. This option is incorrect as only terminal potential difference changes while emf remains same

Q145. The minimum energy of photon for pair production is:

A. 1.023V
B. 1.026V
C. 1.02MeV✓
D. 1.02GeV
E. 1.02keV

Explanation: The rest-mass energy of each of these charged particles is equivalent to 0.511 MeV and, therefore, pair production is not possible below a “threshold” of 1.022 MeV. Even though the threshold for this reaction is just >1 MeV, pair production does not become important until a photon energy of ∼4 MeV is reached

Why the other options are wrong

A. This option is incorrect as energy of photon for electron pair is 1.02MeV
B. This option is incorrect as energy of photon for electron pair is 1.02MeV
D. This option is incorrect as energy of photon for electron pair is 1.02MeV
E. This option is incorrect as energy of photon for electron pair is 1.02MeV

Q146. The mathematical equation representing Faraday's law is:

A. E= NI/t
B. E=Nθ/t✓
C. E= NI/t
D. E=-θ/T
E. E=-(θ)I

Explanation: The mathematical equation representing Faraday's law is Option B. As it is a numerical only one option is correct

Why the other options are wrong

A. This is not correct representation of Faraday's law.
C. This is not correct representation of Faraday's law.
D. This is not correct representation of Faraday's law.
E. This is not correct representation of Faraday's law.

Q147. A cyclist moving on a circular track skids because:

A. The limiting friction is perpendicular to the centripetal force
B. The limiting friction is greater than the require centripetal force
C. The limiting friction is opposite to the centripetal force
D. The limiting friction is equal to the require centripetal force
E. The limiting friction is less than the required cenntripetal force✓

Explanation: A cyclist moving on a circular track skids because: The limiting friction is less than the required centripetal force which helps him continue his motion. So option E is the correcct answer.

Why the other options are wrong

A. This option is incorrect because cyclist skids when limiting friction is less than required one
B. This option is incorrect because cyclist skids when limiting friction is less than required one
C. This option is incorrect because cyclist skids when limiting friction is less than required one
D. This option is incorrect because cyclist skids when limiting friction is less than required one

Q148. A body is dropped from certain height and falls freely, its velocity after 5 seconds will be:

A. 94m/s
B. 9.4m/s
C. 0.49m/s
D. 4.9m/s
E. 49m/s✓

Explanation: To determine the velocity of a body that falls freely, we can use the equation for free fall: v = gt Where: v is the final velocity, g is the acceleration due to gravity (approximately 9.8 m/s²), and t is the time. In this case, the body has fallen for 5 seconds, so we can substitute the values into the equation: v = (9.8 m/s²)(5 s) = 49 m/s Therefore, the correct answer is option (e): 49 m/s. As it is numerical only one option E is correct.

Why the other options are wrong

A. This option is incorrect as per calculations .
B. This option is incorrect as per calculations .
C. This option is incorrect as per calculations .
D. This option is incorrect as per calculations .

Q149. Two transverse travelling waves are presented by these equations:y1 = A sin(kx- ωt) and y2 = A sin(ωt−kx-theta). These two waves differ in:

A. Amplitude
B. Frequency
C. Wavelength
D. Phase✓
E. Direction of propagation

Explanation: These two waves differ in phase, therefore option D is the correct answer.

Why the other options are wrong

A. This option is not correct.
B. This option is not correct.
C. This option is not correct.
E. This option is not correct.

Q150. In equations E=.-V/r Negative sign indicates that:

A. E' points towards increasing V
B. E' points toward decreasing V✓
C. E' is perpendicular to V
D. E' is parallel to V
E. E' is opposite to V

Explanation: The relation E = − dV / dr (or in vector form E = −∇V) shows how the electric field relates to electric potential. The negative sign indicates that: The electric field always points in the direction in which the electric potential decreases most rapidly.

Why the other options are wrong

A. That's an incorrect option . Negative sign indicates that E points towards decreasing V
C. That's an incorrect option . Negative sign indicates that E points towards decreasing V
D. That's an incorrect option . Negative sign indicates that E points towards decreasing V
E. That's an incorrect option . Negative sign indicates that E points towards decreasing V

Q151. The path of a neutron moving perpendicular to magnetic field is:

A. Curve
B. Straight line✓
C. Circular path
D. Ellipse of Parabola
E. Parabola

Explanation: The trajectory of neutron when it is projected perpendicular to a magnetic field is a straight line.

Why the other options are wrong

A. Since, straight line is the correct answer, this option is wrong.
C. Since, straight line is the correct answer, this option is wrong.
D. Since, straight line is the correct answer, this option is wrong.
E. Since, straight line is the correct answer, this option is wrong.

Q152. A battery of emt E has an internal resistance 'r'. If current I is drawn then terminal potential V1 is given by:

A. V1=E+Ir
B. V1 =E-Ir✓
C. V1 =E/1-r
D. V1 = Er
E. V1 =E/I+r

Explanation: The terminal potential (V1) of a battery with an internal resistance (r) when a current (I) is drawn can be calculated using the formula: V1 = E - Ir As it is a numerical only one option B is correct.

Why the other options are wrong

A. This option is incorrect as per formula.
C. This option is incorrect as per formula.
D. This option is incorrect as per formula.
E. This option is incorrect as per formula.

Q153. The instantanous emf generated by alternating current generator is written as:

A. E=NωABsinωt✓
B. E=BNAcossinωt
C. E=BINA
D. E = E0/BINA
E. E=BNAω

Explanation: The instantaneous emf generated by the alternating current generator is written as : E= NωABsinωt. As it is a numerical only one option A is correct.

Why the other options are wrong

B. This is incorrect relation for the instantanous emf generated by alternating current generator.
C. This is incorrect relation for the instantanous emf generated by alternating current generator.
D. This is incorrect relation for the instantanous emf generated by alternating current generator.
E. This is incorrect relation for the instantanous emf generated by alternating current generator.

Q154. A bullet is fired horizontally with 20m/s. In the absence of air friction its horizontal velocity after 2 second will be:

A. 10m/s
B. 05m/s
C. 60 m/s
D. 40m/s
E. 20m/s✓

Explanation: In the absence of air friction, the horizontal velocity of a projectile remains constant throughout its motion. Therefore, the horizontal velocity of the bullet after 2 seconds will still be 20 m/s. So, the correct answer is: 20 m/s. As it is a numerical only one option E is correct.

Why the other options are wrong

A. Since the correct answer is: 20 m/s hence this option is incorrect.
B. Since the correct answer is: 20 m/s hence this option is incorrect.
C. Since the correct answer is: 20 m/s hence this option is incorrect.
D. Since the correct answer is: 20 m/s hence this option is incorrect.

Q155. If ′R ′ is the Rydberg constant for hydrogen, then the wave number of the first line in the Lyman series is:

A. 4RH/3
B. RH/4
C. 4/RH
D. 4/3RH
E. 3R/4✓

Explanation: If ′R ′ is the Rydberg constant for hydrogen, then the wave number of the first line in the Lyman series is: 3R/4. As it is a numerical only one option D is correct.

Why the other options are wrong

A. This option is not correct as per calculations.
B. This option is not correct as per calculations.
C. This option is not correct as per calculations.
D. This option is not correct as per calculations.

Q156. The ratio of molar specific heat of a gas at constant pressure to its molar specific heat at constant volume is:

A. Equal to minus one
B. Equal to zero
C. Greater than one✓
D. Less than one
E. Equal to one

Explanation: The ratio of molar specific heat at constant pressure (Cp) to molar specific heat at constant volume (Cv) for an ideal gas is given by: γ = Cp/Cv In general, for an ideal gas, γ can take values greater than one. Therefore option C is the correct answer.

Why the other options are wrong

A. This option is not correct.Cp/Cv=γ and it's value is greater than one .
B. This option is not correct.Cp/Cv=γ and it's value is greater than one .
D. This option is not correct.Cp/Cv=γ and it's value is greater than one .
E. This option is not correct.Cp/Cv=γ and it's value is greater than one .

Q157. If mass and speed of a moving object is doubled, the kinetic energy will be:

A. Eight times✓
B. Four times
C. Doubled
D. Sixteen times
E. Six times

Explanation: If mass and speed of a moving object is doubled, the kinetic energy will be Eight times, so option A is the correct answer.

Why the other options are wrong

B. This option is not correct as per calculations.
C. This option is not correct as per calculations.
D. This option is not correct as per calculations.
E. This option is not correct as per calculations.

Q158. The electric field intensity between two uniformly, oppositely charged parallel plates is:

A. ε0 / σ
B. 2σ/ε0
C. σ/ε0✓
D. σ/E

Explanation: The electric field intensity between two uniformly, oppositely charged parallel plates can be given by: σ/ε0 where σ is the surface charge density on the plates and ε0 is the permittivity of free space. The surface charge density σ is defined as the total charge Q divided by the area A of one of the plates: σ = Q/A The electric field intensity E0 between the plates is related to the surface charge density by the equation: E = σ/ε As it is a numerical only one option D is correct.

Why the other options are wrong

A. This is not correct formula for electric intensity between oppositely charged plates.
B. This is not correct formula for electric intensity between oppositely charged plates.
D. This is not correct formula for electric intensity between oppositely charged plates.

Q159. A box of mass m = 6 kg slides with speed v = 4m/s across a frictionless floor. It suddenly explodes into two places. One piece, with mass m1= 2kg moves in same direction with speed vi= 8 m/s. the velocity of the second piece is:

A. 6m/sec
B. 3m/sec
C. 1m/sec
D. 2m/sec✓
E. 4m/sec

Explanation: Before the explosion: Total momentum = (mass of box) * (initial velocity of box) = m * v After the explosion: Total momentum = (mass of piece 1) * (velocity of piece 1) + (mass of piece 2) * (velocity of piece 2) We are given the following information: mass of box (m) = 6 kg initial velocity of box (v) = 4 m/s mass of piece 1 (m1) = 2 kg velocity of piece 1 (v1 )= 8 m/smass of 2nd piece should be 4 m/sSo, mv = m1v1 + m2v26(4) = 2(8) + 4v224 = 16 + 4v224 - 16 = 4v28 = 4v2v2 = 2 m/s

Why the other options are wrong

A. This option is incorrect as per calculations .
B. This option is incorrect as per calculations .
C. This option is incorrect as per calculations .
E. This option is incorrect as per calculations .

Q160. The intensity level (sound level) of faintest audible intensity is:

A. 160 decibel
B. Zero decibel✓
C. 140 decibel
D. 120 decibel
E. 60 decibel

Explanation: The faintest audible intensity corresponds to a sound level of: Zero decibel. Zero decibel (0 dB) represents the threshold of human hearing, which is the lowest sound intensity that the average human ear can detect. So option B is the correct answer.

Why the other options are wrong

A. This option is not correct.
C. This option is not correct.
D. This option is not correct.
E. This option is not correct.

Q161. If 2uF and 4 uF capacitors connected in series. Their equivalent capacitance will be:

A. 8uF
B. 0.75 uF
C. 1.33 uF✓
D. 6μF
E. 2 μF

Explanation: When capacitors are connected in series, the inverse of the equivalent capacitance is equal to the sum of the inverses of the individual capacitances. For two capacitors connected in series with capacitances 2 μF and 4 μF, the equivalent capacitance (C_eq) can be calculated as: 1/C_eq = 1/2 + 1/4 Simplifying this equation: 1/C_eq = 2/4 + 1/4 1/C_eq = 3/4 C_eq = 4/3 μF Therefore, the equivalent capacitance of the 2 μF and 4 μF capacitors connected in series is: 1.33 μF. As it is a numerical only one option C is correct

Why the other options are wrong

A. This option is not correct as per calculations
B. This option is not correct as per calculations
D. This option is not correct as per calculations
E. This option is not correct as per calculations

Q162. The experimental proof of particle nature of light is:

A. Pair production
B. Photo electric effect✓
C. Davison-Germer experiment
D. De- Broglie concept
E. Compton's effect

Explanation: The experimental proof of the particle nature of light is: Photoelectric effect. This observation supported the particle-like behavior of light, as the energy transfer from the incident photons to the electrons could only be explained by treating light as discrete particles. So option B is the correcct answer.

Why the other options are wrong

A. This option is incorrect. Pair production explains the particle nature of light but doesn't gives it's experimental proof .
C. This option is incorrect . Davison germer experiment explains wave -particle duality of light.
D. This option is incorrect. De Broglie concept explains wave -particle duality of light.
E. This option is incorrect. Compton's effects explains particles nature of light but doesn't gives it's experimental proof .

Q163. The electrical energy dissipated as heat in a resistor is:

A. V2R
B. V2Rt
C. I2R
D. I2Rt✓
E. IR

Explanation: power (P) dissipated in a resistor can be determined using the formula: Power = Voltage * Current. Since the voltage across a resistor is V and the current flowing through it is I, the power can be expressed as: Power = V * I. Substituting this into the energy formula, we get: Energy = (V * I) * Time. Using Ohm's Law (V = IR), we can substitute for V: Energy = (IR * I) * Time. Simplifying, we get: Energy = I^2 * R * Time. As it is a numerical only one option D is correct.

Why the other options are wrong

A. This option is not correct as per formula.
B. This option is not correct as per formula.
C. This option is not correct as per formula.
E. This option is not correct as per formula.

Q164. One kilowatt hour is equal to:

A. 3.6 x 106J✓
B. 36 x 10-6 J
C. 3.6 x 105 J
D. 36 x 10-5 J
E. 36 x 106 J

Explanation: One kilowatt-hour (kWh) is equal to: 3.6 x 106 J. The kilowatt-hour is a unit of energy commonly used to measure electricity consumption. To convert kilowatt-hours to joules, we use the conversion factor: 1 kilowatt-hour = 3.6 x 106 joules. As it is a numerical only one option A is correct.

Why the other options are wrong

B. This option is not correct.
C. This option is not correct .
D. This option is not correct.
E. This option is not correct.

Q165. Unit, joule per coulumb is equal to:

A. Volt✓
B. Ampere
C. Henry
D. Tesla
E. Newton

Explanation: The unit joule per coulomb is equal to: a) Volt. Joule per coulomb is the unit of electric potential difference or voltage. It represents the amount of energy transferred per unit charge. The symbol for volt is V.

Why the other options are wrong

B. This option is not correct as per formula.
C. This option is not correct as per formula.
D. This option is not correct as per formula.
E. This option is not correct as per formula.

Q166. According to the law of radioactive decay, the rate of disintegration is directly proportional to:

A. Pressure
B. Density of substance
C. Volume of substance
D. Number of atoms present✓
E. Temperature

Explanation: According to law of radioactive decay, the rate of disintegration is direct proportional to number of atoms present. So option D is the correcct answer.

Why the other options are wrong

A. This option is incorrect as phenomenon of radioactivity doesn't depends on pressure, volume, or temperature of substance as it is spontaneous process.
B. This option is incorrect as phenomenon of radioactivity doesn't depends on pressure, volume, or temperature of substance as it is spontaneous process.
C. This option is incorrect as phenomenon of radioactivity doesn't depends on pressure, volume, or temperature of substance as it is spontaneous process.
E. This option is incorrect as phenomenon of radioactivity doesn't depends on pressure, volume, or temperature of substance as it is spontaneous process.

Q167. The Eddy current loss in a transformer can be reduced by:

A. Using thick copper core
B. Using thick non magnetic core
C. Using iron core
D. Using laminated iron core✓

Explanation: Option "d) Using laminated iron core" is the correct choice. Laminated cores help to mitigate eddy current losses in transformers by introducing insulating barriers that disrupt the circular flow of induced eddy currents, leading to improved transformer efficiency. The other options (a, b, and c) do not directly address the reduction of eddy current losses in transformers.

Why the other options are wrong

A. Using a thick copper core in a transformer can help reduce resistive losses, but it does not directly address eddy current losses. Copper is a good conductor of electricity, and using a thick copper core helps decrease the resistance of the windings, resulting in lower copper losses (I^2R losses) due to the flow of current. However, eddy current losses primarily occur in the magnetic core of the transformer, not in the copper windings.
B. A thick non-magnetic core would not be beneficial for reducing eddy current losses. Eddy currents are induced circulating currents that occur in the magnetic core of the transformer when it is subjected to changing magnetic fields. Non-magnetic materials do not respond strongly to magnetic fields, so they are not suitable for the core of a transformer, which requires a material with high magnetic permeability to efficiently transfer magnetic flux
C. Using an iron core in a transformer is a common practice, as iron has high magnetic permeability, allowing it to efficiently carry and transfer magnetic flux. However, using an iron core alone does not reduce eddy current losses. In fact, eddy current losses are more pronounced in solid blocks of conductive materials like iron, as there are no barriers to inhibit the circular flow of induced eddy currents.

Q168. The absolute gravitational potential energy "U" of an object of mass 'm' on earth's surface is given by:

A. U=-GmME/RE✓
B. U= GmME/RE
C. U=GmME/RE²
D. U=GME/RE²
E. U=-GME/RE²

Explanation: As it is a mathematical expression answer so only one option A is correct.

Why the other options are wrong

B. This option is not correct.
C. This option is not correct.
D. This option is not correct.
E. This option is not correct

Q169. A charge 'q' is moving with velocity "v", parallel to a magnetic field B. The magnetic force (F) on charge "q" is:

A. F= qvB sinθ
B. F= qvB
C. F=-qvB
D. F=0✓
E. F = qB/v

Explanation: The magnetic force on a moving charge (q) in a magnetic field (B) can be calculated using the formula: F = q * v * B * sin theta In this case, the charge (q) is moving parallel to the magnetic field (B), which means the angle theta is 0 degrees. When the angle is 0 degrees, sin(theta) is 0, so the term sin(theta) becomes zero. As a result, the magnetic force simplifies to: F = q * v * B * 0 = 0. F = 0. As it is a numerical only one option D.is correct

Why the other options are wrong

A. When the charge (q) is moving parallel to the magnetic field (B), the force is not qvB sinθ
B. When the charge (q) is moving parallel to the magnetic field (B), the force is not qvB.
C. When the charge (q) is moving parallel to the magnetic field (B), the force is not -qvB.
E. When the charge (q) is moving parallel to the magnetic field (B), the force is not qB/V.

Q170. Resistors of 5 ohm and 10 ohm are connected parallel. If the potential difference across 5 ohm resistor is 20 volt then current through 10 ohm resistor will be:

A. 30.5 ampere
B. 20 ampere
C. 4 ampere
D. 10 ampere
E. 2 ampere✓

Explanation: When resistors are connected in parallel, the potential difference across each resistor is the same. here,, the potential difference across the 5-ohm resistor is given as 20 volts. Using Ohm's Law (V = IR), we can find the current through the 10-ohm resistor: V = IR 20 V = I * 10 Ω I = 20 V / 10 Ω I = 2 A As it is a numerical only one option E is correct.

Why the other options are wrong

A. According to given data, it cannot be correct option.
B. According to given data, it cannot be correct option.
C. According to given data, it cannot be correct option.
D. According to given data, it cannot be correct option.

Q171. Helicopter with weight W is ascending with zero acceleration. Upward force F on the helicopter is:

A. F>W
B. F<W
C. F=0
D. F=W✓

Explanation: When a helicopter is ascending with zero acceleration, the upward force on the helicopter is equal to its weight. So, the upward force (F) exerted on the helicopter is indeed equal to its weight (W). It's all about achieving that balance of forces to maintain a steady ascent.

Why the other options are wrong

A. False.
B. False.
C. False.

Q172. A sound wave travels from one medium to another, which one of the following characteristic of sound remains unchanged?

A. Amplitude
B. Velocity
C. Pitch✓
D. Quality
E. Wavelength

Explanation: When a sound wave travels from one medium to another, the characteristic that remains unchanged is: Pitch. Pitch is determined by the frequency of the sound wave, which is the number of oscillations per unit time. So option C is the correct answer.

Why the other options are wrong

A. This option is incorrect. As wave travels from one medium to another medium it's amplitude changes.
B. This option is incorrect. As wave travels from one medium to another medium it's velocity changes.
D. This option is not correct. As wave travels from one medium to another it's quality may change i-e it's amplitude may change .
E. This option is not correct as wave travels from one medium to another it's wavelength may change .

Q173. For efficient transfer of electricity through cables over the long distance:

A. Both the current and voltage must be low
B. The current must be low and voltage high✓
C. Both the current and voltage must be high
D. The voltage must be zero and current low
E. The voltage must low and current high

Explanation: For efficient transfer of electricity through cables over long distances, the preferable approach is to have: option b) The current must be low and voltage high.

Why the other options are wrong

A. This option is not correct. For transmission through long distance the current must be low to prevent loses and voltage must be high
C. This option is not correct. For transmission through long distance the current must be low to prevent loses and voltage must be high
D. This option is not correct. For transmission through long distance the current must be low to prevent loses and voltage must be high
E. This option is not correct. For transmission through long distance the current must be low to prevent loses and voltage must be high

Q174. When a body moves with uniform velocity then its:

A. Average velocity is zero
B. Instantaneous velocity is greater than average velocity
C. Instantaneous velocity is zero
D. Instantaneous velocity is equal to average velocity✓
E. instantaneous velocity in less than average velocity

Explanation: When a body moves with uniform velocity, its instantaneous velocity remains constant over time. Therefore, the correct answer is: Instantaneous velocity is equal to average velocity. In uniform velocity, velocity does not change. Since the velocity remains constant, the instantaneous velocity at any given moment is equal to the average velocity over the entire duration of the motion. So option D is the correct answer.

Why the other options are wrong

A. When body moves with uniform velocity it's average velocity is constant not zero .
B. This option is not correct. When body moves with uniform velocity it's instantaneous velocity is equal to average velocity .
C. This option is not correct. When it's uniform velocity instantaneous velocity is constant not zero .
E. This option is not correct. When there is uniform velocity, it's instantaneous velocity equals average velocity .

Q175. Every particle of a rotating disc moves with:

A. Constant linear velocity
B. Constant angular velocity✓
C. Constant tangential velocity
D. Constant linear displacement
E. Constant linear momentum

Explanation: Every particle of a rotating disc moves with constant angular velocity. So option B is the correct answer.

Why the other options are wrong

A. This option is not correct as every particle of rotating body moves with constant angular velocity. As their is rotating body mentioned So we would not consider linear velocity.
C. This option is not correct. The tangential velocity is not constant in rotating body as it changes it's direction continuously.
D. This option is not correct. In rotating body linear displacement is zero.
E. This option is not correct. In rotating body we don't consider linear momentum.

Q176. A proton of charge 1.6x10-19 C is moved through a potential difference of 20 volt The energy gained by the proton is:

A. -32 x 10-19J
B. 32 x 10-19J✓
C. -32 x 1019 J
D. 32 x 1019 J
E. Zero

Explanation: The energy gained by a charged particle when it is moved through a potential difference can be calculated using the equation: Energy = charge (q) * potential difference (V). In this case, the charge of the proton is 1.6 x 10^(-19) C, and the potential difference is 20 volts. Plugging in these values into the equation, we get: Energy = (1.6 x 10^(-19) C) * (20 V). Calculating this expression, we find: Energy = 3.2 x 10^(-18) J. Therefore, the energy gained by the proton is 3.2 x 10^(-18) joules. As it is a numerical only one option B is correct.

Why the other options are wrong

A. This option is not correct as per calculations.
C. This option is not correct as per calculations.
D. This option is not correct as per calculations.
E. This option is not correct as per calculations.

Q177. Distance between two consecutive antinodes in standing wave is:

A. λ/4
B. λ/2✓
C. 2 λ
D. 5λ/2
E. 3 λ /2

Explanation: Distance between two consecutive antinodes in standing wave is λ/2, so option B is correct.Nodes and antinodes are known to generate the stationary waves. In a given stationary wave, the distance between any given two successive nodes or any two successive antinodes is always half of the wavelength. The distance between the two successive nodes is λ2 .

Why the other options are wrong

A. Distance between two consecutive antinodes in standing wave is not λ/4.
C. Distance between two consecutive antinodes in standing wave is not 2λ.
D. Distance between two consecutive antinodes in standing wave is not 5λ/2.
E. Distance between two consecutive antinodes in standing wave is not 3λ/2.

Q178. A conducting wire of resistivity' p is cut into two equal parts. The resistivity of each part will be:

A. The same✓
B. One fourth
C. √2 times
D. Halved
E. Doubled

Explanation: When a conducting wire is cut into two equal parts, the resistivity (ρ) of each part remains the same. Resistivity is an intrinsic property of a material and does not depend on the size or shape of the object. So option A is the correct answer.

Why the other options are wrong

B. This option is incorrect as resistivity of wire doesn't depends on geometry of wire i-e it's length and area.
C. This option is incorrect as resistivity of wire doesn't depends on geometry of wire i-e it's length and area.
D. This option is incorrect as resistivity of wire doesn't depends on geometry of wire i-e it's length and area.
E. This option is incorrect as resistivity of wire doesn't depends on geometry of wire i-e it's length and area.

Q179. If the given spring of spring constant K is cut into three identical segments the sum of spring constant of each segment:

A. 1K
B. K/2
C. K/3
D. 3K✓
E. 4K

Explanation: When a spring is cut into segments, the spring constant of each segment remains the same. Therefore, if the original spring has a spring constant K, each segment will also have a spring constant of K. So the summation will be 3K. Therefore option D is the correct option.

Why the other options are wrong

A. This option is not correct as per the calculations
B. This option is not correct as per the calculations
C. This option is not correct as per the calculations
E. This option is not correct as per calculations

Q180. Four cells of emf 3volt are connected in series to form a battery. Net emf of the combination is:

A. 12volt✓
B. 1.33volt
C. 9volt
D. 7volt
E. 3volt

Explanation: When cells are connected in series, the net electromotive force (EMF) of the combination is equal to the sum of the individual EMFs. In this case, we have four cells with an EMF of 3 volts each. Therefore, the net EMF of the combination will be : Net EMF = 3 volts + 3 volts + 3 volts + 3 volts = 12 volts. As it is numerical only one option A is correct.

Why the other options are wrong

B. This option is not correct as per calculations
C. This option is not correct as per calculations
D. This option is not correct as per calculations
E. This option is not correct as per calculations

Q181. The rate of change of linear momentum of a body is:

A. Net force✓
B. Net displacement
C. Net torque
D. Net inertia
E. Net velocity

Explanation: Force is defined as: The rate of change of linear momentum of a body. So option A is correct.

Why the other options are wrong

B. This option is not correct as per formula
C. This option is not correct as per formula
D. This option is not correct as per formula
E. This option is not correct as per formula

Q182. The most appropriate mathematical expression of smple harmonic motion is:

A. a ∝ x
B. a ∝-x✓
C. a=x
D. a = kx
E. a = -x

Explanation: The most appropriate mathematical expression of smple harmonic motion is: a directly proprtional -x, so option B is correct answer.

Why the other options are wrong

A. This option is not correct as necessary condition for SHM is "a "directly proportional to "-x".
C. This option is not correct as necessary condition for SHM is "a "directly proportional to "-x".
D. This option is not correct as necessary condition for SHM is "a "directly proportional to "-x".
E. This option is not correct as necessary condition for SHM is "a "directly proportional to "-x".

Q183. A body is moving in a circle with constant speed, with radius of circle is 'r' and time period 'T' the centripetal acceleration ac is given by:

A. ac = 4πr2/T
B. ac = 4π2r/T2✓
C. ac = 4πr/T
D. ac = 4π2r2/T
E. ac = 4πr2/T2

Explanation: A body is moving in a circle with constant speed, with radius of circle is 'r' and time period 'T' the centripetal acceleration is given by:ac= v2/r{Since: v=rw or v=r(2π/T)}ac= (2πr)2/T2rac= 4π2r2/T2rac= 4π2r/T2

Why the other options are wrong

A. A body is moving in a circle with constant speed, with radius of circle is 'r' and time period 'T' the centripetal acceleration is given by:ac= v2/r{Since: v=rw or v=r(2π/T)}ac= (2πr)2/T2rac= 4π2r2/T2rac= 4π2r/T2
C. A body is moving in a circle with constant speed, with radius of circle is 'r' and time period 'T' the centripetal acceleration is given by:ac= v2/r{Since: v=rw or v=r(2π/T)}ac= (2πr)2/T2rac= 4π2r2/T2rac= 4π2r/T2
D. A body is moving in a circle with constant speed, with radius of circle is 'r' and time period 'T' the centripetal acceleration is given by:ac= v2/r{Since: v=rw or v=r(2π/T)}ac= (2πr)2/T2rac= 4π2r2/T2rac= 4π2r/T2
E. A body is moving in a circle with constant speed, with radius of circle is 'r' and time period 'T' the centripetal acceleration is given by:ac= v2/r{Since: v=rw or v=r(2π/T)}ac= (2πr)2/T2rac= 4π2r2/T2rac= 4π2r/T2

Q184. The kinetic energy of an electron in first Bohr radius of H-atom is:

A. 13.6J
B. 13.6eV✓
C. -13.6eV
D. 13.6keV
E. 13.6kJ

Explanation: The kinetic energy of an electron in the first Bohr radius of a hydrogen atom is 13.6 eV. The negative sign (-13.6 eV) is not used to represent the kinetic energy but rather the total energy (including both kinetic and potential energy) of the electron in the hydrogen atom.

Why the other options are wrong

A. This value is incorrect. In joules, kinetic energy must be 2.18 * 10 -18J. The value will be positive as kinetic energy has positive value.
C. This value is of total energy not of kinetic energy.
D. This value is incorrect.
E. This value is incorrect.

Q185. Lenz's law is a form of the:

A. Law of conservation of momenyum
B. Law of conservation of charge
C. Law of conservation of angular momentum
D. Law of conservation of energy✓
E. Law of conservation of mass

Explanation: As mentioned in STB, it is form of law of conservation of energy. So option D is correct.

Why the other options are wrong

A. That's incorrect. Lenz law is manifestation of law of conservation of energy.
B. That's incorrect. Lenz law is manifestation of law of conservation of energy.
C. That's incorrect. Lenz law is manifestation of law of conservation of energy.
E. That's incorrect. Lenz law is manifestation of law of conservation of energy.

Q186. The rate of doing work is zero, when the angle between force and velocity is:

A. θ = 60
B. θ = 180
C. θ = 0
D. θ = 45
E. θ = 90✓

Explanation: The rate of doing work is zero when the angle between force and velocity is 90 degrees (perpendicular). work (W) is given by the equation: W = F * d * cos(theta), When the angle between force and velocity is 90 degrees, cos(theta) becomes zero. Since work is directly proportional to cos(theta), if cos(theta) is zero, the work done is also zero.As it is numerical only one option E is correct.

Why the other options are wrong

A. That's incorrect , at this angle work done is half of the actual work done .
B. That's incorrect. At this angle work done becomes negative.
C. This option is not correct. At this angle work done becomes maximum i-e positive .
D. This option is not correct. At this angle work done becomes 1/√2 of actual work done.

Q187. Half life of a radioactive sample is given by:

A. (0.693)2/λ
B. T = (0.693)
C. (0.693) x λ
D. T =√0.693/λ
E. 0.693/λ✓

Explanation: Half-life of a radioactive sample is given by: 0.693/λAs it is numerical only one option E is correct

Why the other options are wrong

A. This option is not correct as per formula.
B. This option is not correct as per formula.
C. This option is not correct as per formula.
D. This option is not correct as per formula.

Q188. Two similar point charges, each of 1 coulomb, placed in free space 1m apart, repel each other with a force:

A. 8.85×10-12 N
B. 1.602x10-19 N
C. 1N
D. 6.67x 10-11 N
E. 9×109 N✓

Explanation: Mathematically, Coulomb's Law is expressed as: F = k * (q1 * q2) / r^2, where k is the electrostatic constant, approximately equal to 9 × 10^9 N·m^2/C^2. In this case, we have two similar point charges, each with a charge of 1 coulomb (q1 = q2 = 1 C), and they are placed 1 meter apart (r = 1 m). Plugging these values into Coulomb's Law, we get: F = (9 × 10^9 N·m^2/C^2) * (1 C * 1 C) / (1 m)^2. Simplifying the equation, we have F = 9 × 10^9 N. Therefore, the repulsive force between the two 1-coulomb charges placed 1 meter apart in free space is 9 × 10^9 Newtons. As it is numerical only one option E is correct.

Why the other options are wrong

A. This is incorrect as per calculations.
B. This is incorrect as per calculations.
C. This is incorrect as per calculations.
D. This is incorrect as per calculations.

Q189. In nuclear reaction, 7N14 + 2He4 -> 8O17+_ the missing particle is:

A. Proton✓
B. alpha-particle
C. Electron
D. Position
E. Neutron

Explanation: Adding the atomic numbers on reactant side the answer should be 9. Since oxygen has atomic number 8. it means that another element having atomic number 1 should also be formed to balance the equation. Similarly the reaction between the above reactants should produce a product having mass number of 18 but an Oxygen atom of mass number 17 leaeves room for another atom having mass number 1. In conclusion, the missing particle has an atomic number and mass number 1 which is a Hydrogen Atom 11H also simply known as a proton.

Why the other options are wrong

B. This option is incorrect as per the balancing of a chemical equation.
C. This option is incorrect as per the balancing of a chemical equation.
D. This option is incorrect as per the balancing of a chemical equation.
E. This option is incorrect as per the balancing of a chemical equation.

Q190. The potential difference applied across a diode to reduce depletion layer is:

A. Reverse biasing
B. Forward biasing✓
C. Biasing voltage
D. Junction potential
E. Potential barrier

Explanation: The potential difference applied across a diode to reduce the depletion layer is: Forward biasing. When a diode is forward biased, the positive terminal of the voltage source is connected to the P-type material of the diode, and the negative terminal is connected to the N-type material. This configuration decreases the potential barrier between the P-type and N-type regions of the diode, reducing the width of the depletion layer. So option B is correct.

Why the other options are wrong

A. This option is not correct as applied potential difference increases depletion region in negative biasing.
C. This option is incorrect.
D. This option is incorrect.
E. This option is incorrect.

Q191. A charged particle of mass 'm' and charge 'q' is projected in a magnetic field of induction B at an angle θ. The radius of curvature of its curved path is given by:

A. r=mv/qB
B. r=mv/qBsinθ✓
C. r=mvsinθ/qB
D. r=mvcosθ/qB
E. r=mvB/q

Explanation: Fc = Femv2/r = qvb sinθ r = mv/qbsinθ Hence, option B is correct.

Why the other options are wrong

A. Fc = Femv2/r = qvb sinθ r = mv/qbsinθ
C. Fc = Femv2/r = qvb sinθ r = mv/qbsinθ
D. Fc = Femv2/r = qvb sinθ r = mv/qbsinθ

Q192. Specific heat capacity of a gas is measured in:

A. J.kg K-1
B. J.kg2 K
C. J.kg-1 K-1✓
D. J.kg-1.K
E. J.Kg.K

Explanation: Specific heat capacity of a gas is measured in J.kg-1 K-1 . So the correct option is C.

Why the other options are wrong

A. This option is incorrect as it's not a unit of specific heat capacity.
B. This option is incorrect as it's not a unit of specific heat capacity.
D. This option is incorrect as it's not a unit of specific heat capacity.
E. This option is incorrect as it's not a unit of specific heat capacity.

Q193. First law of thermodynamics is mathematically represented as:

A. ΔW=ΔQ+ΔU
B. ΔU=ΔW-ΔQ
C. ΔQ=ΔW-ΔU
D. ΔQ=ΔU-ΔW
E. ΔU = ΔQ-ΔW✓

Explanation: Option E is the correct representation of first law of thermodynamics.

Why the other options are wrong

A. This is not correct representation of first law of thermodynamics
B. This is not correct representation of first law of thermodynamics
C. This is not correct representation of first law of thermodynamics
D. This is not correct representation of first law of thermodynamics

Q194. The speed of a photon in free space is:

A. 1/√µ0ε0✓
B. 1/2 µ0ε0
C. 1/µ0ε0
D. √µ0ε0
E. µ0ε0

Explanation: Answer : AExplanation : As it is a numerical only one option is correct

Why the other options are wrong

B. This is not correct representation of speed of photon in free space
C. This is not correct representation of speed of photon in free space
D. This is not correct representation of speed of photon in free space
E. This is not correct representation of speed of photon in free space

Q195. what should come next in series:7C, 10F ,14J, 19O

A. 23Q
B. 26N
C. 27X
D. 25U✓
E. 24P

Explanation: The attached image shows how to solve this question:

Why the other options are wrong

A. According to given sequence 23Q cannot be the answer.
B. According to given sequence 26N cannot be the answer.
C. According to fiven sequence, 27X cannot be the answer.
E. According to given sequence 24P cannot be the answer.

Q196. Although most of the lucrative jobs in Pakistan will require a college degree.many of the new jobs require knowledge other than gained in college or university. For workers in those jobs, good basic skills in reading communication and mathematics plays an important role in getting a job & developing a career. From the given information above, what concluded that in today's economy:

A. Extra knowledge is an added benefit for career development
B. People should train their children for technical work
C. Skills in reading, communication & mathematics play an important role in developing a successful career.✓
D. All colleges & universities are worthless,
E. Employment agencies should conduct communicatant role in developing a mathematics classes

Explanation: From the given information above, Option C: Skills in reading, communication & mathematics play an important role in developing a successful career that in today's economy.

Why the other options are wrong

A. That's incorrect option. Paragraph indicates that In today's Pakistani economy: while college degrees are still valuable for many high-paying jobs, practical skills like reading, communication, and math are increasingly essential for new, non-traditional career paths.
B. That's incorrect option. Paragraph indicates that In today's Pakistani economy: while college degrees are still valuable for many high-paying jobs, practical skills like reading, communication, and math are increasingly essential for new, non-traditional career paths.
D. That's incorrect option. Paragraph indicates that In today's Pakistani economy: while college degrees are still valuable for many high-paying jobs, practical skills like reading, communication, and math are increasingly essential for new, non-traditional career paths.
E. That's incorrect option. Paragraph indicates that In today's Pakistani economy: while college degrees are still valuable for many high-paying jobs, practical skills like reading, communication, and math are increasingly essential for new, non-traditional career paths.

Q197. After seven years of suggestions from the environmental department, the Sindh legislation has finally passed an antipollution ordinance. From a reading of language, the legislation promises to be one of the most effective bills in the history of the province. Which of the following can be deducted from the passage?

A. Pollution is not now a problem in the country.
B. To reduce pollution, the legislation must now be enforced.✓
C. The pollution problem will be eliminated in the country.
D. The pollution problem will be eliminated in the process.
E. The pollution problem will be reduced in the province.

Explanation: Option B: To reduce pollution, the legislation must now be enforced, can be deducted from the passage.

Why the other options are wrong

A. That's an incorrect option. As paragraph indicates that Sindh government has introduced a new antipollution law .
C. No, it cannot be deduced that pollution will be eliminated from the country. The paragraph only states that the legislation "promises to be one of the most effective bills in the history of the province." This suggests a significant improvement in pollution control, but it doesn't guarantee complete elimination.
D. No, it cannot be deduced that pollution will be eliminated from the country. The paragraph only states that the legislation "promises to be one of the most effective bills in the history of the province." This suggests a significant improvement in pollution control, but it doesn't guarantee complete elimination.
E. No, it cannot be deduced that pollution will be eliminated from the country. The paragraph only states that the legislation "promises to be one of the most effective bills in the history of the province." This suggests a significant improvement in pollution control, but it doesn't guarantee complete elimination.

Q198. After the declaration of company election, the elected chairperson gave his message to the workers that "The responsibility of the management is to serve and not to dominate Workers. Which of the following is one basic "assumption" underlying the chairperson's statement?

A. The management is capable of dominating the workers.
B. One must be decesive when facing company union for the first time.
C. Domination over workers by the management is a virtue.
D. The management, preceding the company administration had been impossible.
E. The management chooses to serve rather than dominate the workers.✓

Explanation: The basic assumption underlying the chairperson's statement is: e) The management chooses to serve rather than dominate the workers. The chairperson's message suggests that the responsibility of the management is to serve the workers, indicating a belief or assumption that the management's intention is to prioritize service and support for the workers rather than exerting dominance or control over them. This assumption reflects a perspective of a cooperative and mutually beneficial relationship between the management and the workers, emphasizing the importance of serving the needs and interests of the workers in the company.

Why the other options are wrong

A. This assumption is incorrect.
B. This assumption is incorrect.
C. This assumption is incorrect.
D. This assumption is incorrect.

Q199. Scientists recently published that influenza spreads around the world more efficiently in the modern era due to commercial air travel. Flu symptoms are severe enough that the sick would likely cancel or reschedule air travel, but an infected person can travel across the globe before the first signs appear. Further, if symptoms develop while someone is on a plane, the patient's cough can spread the virus easily in an enclosed and closely packed environment. Which of the following would best minimize the role air travel can play in the spread of influenza during a pandemic?

A. Refusing to allow children, the elderly, or others who are especially vulnerable to flu to travel by air during a pandemic.
B. Requiring all air travelers to wash their hands before hoarding a plane.
C. Requiring air travelers to receive flu vaccinations far enough in advance of the trip to provide protection against the disease.
D. Installing air filtration systems in the planes to kill any flu virus particles flowing through the filters
E. Conducting medical examinations during the boarding process and prohibiting passengers with flu symptoms from flying.✓

Explanation: Among the options provided, the one that would best minimize the role air travel can play in the spread of influenza during a pandemic is: e) Conducting medical examinations during the boarding process and prohibiting passengers with flu symptoms from flying. This approach would involve screening passengers for flu symptoms before they board a plane. If someone exhibits flu symptoms, they would be prohibited from flying, reducing the risk of spreading the virus within the enclosed and closely packed environment of the plane. By identifying and preventing individuals with flu symptoms from traveling, the likelihood of infected individuals spreading the virus during air travel can be significantly reduced. The other options mentioned may have some benefits in general terms but may not directly address the specific challenge of minimizing the spread of influenza during a pandemic through air travel. For example: a) Refusing to allow vulnerable individuals to travel by air during a pandemic may be challenging to enforce and may not adequately prevent the spread of the virus. b) Requiring handwashing before boarding a plane can help reduce the transmission of some diseases but may not effectively address the airborne transmission of influenza. c) Requiring flu vaccinations in advance of travel can be beneficial but may not be feasible or practical for all travelers, and it does not address the immediate risk during air travel. d) Installing air filtration systems on planes can improve air quality but may not completely eliminate the risk of influenza transmission. Therefore, conducting medical examinations and prohibiting passengers with flu symptoms from flying is the option that specifically targets the prevention of influenza transmission during air travel.

Why the other options are wrong

A. That's an incorrect option. That's not a solution refusing the individuals vulnerable to flu to travel. To minimize flu spread via air travel during a pandemic: * Implement pre-flight symptom screening. * Quarantine symptomatic passengers during flights.
B. That's an incorrect option. To minimize flu spread via air travel during a pandemic: * Implement pre-flight symptom screening. * Quarantine symptomatic passengers during flights are more effective measures.
C. That's an incorrect option. Requiring flu vaccinations in advance of travel can be beneficial but may not be feasible or practical for all travelers, and it does not address the immediate risk during air travel.
D. That's an incorrect option as air filtration systems alone cannot be effective against airborne diseases. Air purifiers are most effective when used in conjunction with other preventive measures, such as good ventilation, hand hygiene, and social distancing.

Q200. P. Q, R, S and T are five people in the family, if P is the daughter of Q. Q is the son of R, R is father of S, while T is the daughter of P then which if following is true:

A. R is the uncle of P
B. R is the grandfather of P✓
C. P and R are sisters
D. Q is daughter of S
E. That's an incorrect option. P is sister of T.

Explanation: According to given statement, P is daughter of Q who is son of R, so R is grand-father of P.

Why the other options are wrong

A. That's an incorrect option.R is grand father of P.
C. That's an incorrect option.R is grand father of P.
D. That's an incorrect option. Q and S are brothers.
E. P is mother of T.

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