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Etea Mdcat 2009 — Solved Past Paper with Answers

All 200 MCQs from Etea Mdcat 2009, solved with the correct answer highlighted and a full explanation for every question. This is a free MDCAT KPK / ETEA past paper — no signup, no ads. Practise it interactively in timed mode, drill more with free MDCAT MCQs, or browse all KPK / ETEA papers.

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Q1. It is useless _ them; they are sure to have left the house by now

  • A. To call
  • B. Call
  • C. Called
  • D. Calling

Explanation: The correct answer is 'to call' because the sentence discusses a potential action the speaker is considering taking in the present. The infinitive 'to call' expresses this idea of contemplation or planning without execution. The other options do not fit the context: 'call' suggests a command, 'called' implies the action has already happened, and 'calling' indicates an ongoing action. None of these align with the sentence's suggestion that the action is merely being contemplated.

Why the other options are wrong
  • B. The form 'call' would suggest an imperative or a command, which does not fit the context of this sentence. The speaker is not issuing a command but rather considering an action.
  • C. 'Called' is in the past tense, which would imply that the action has already been completed. The sentence suggests the action is still under consideration and has not been executed, making 'called' an incorrect choice.
  • D. 'Calling' suggests an ongoing action, which does not align with the sentence's implication that the speaker is only considering the action. The use of the gerund form does not fit the context of contemplation.

Q2. Invaluable is closest in meaning to:

  • A. External valuable
  • B. Worthless
  • C. Highly expensive
  • D. Fertile

Explanation: The correct answer is option C:Highly expensive. The closest meaning to "invaluable" is "highly valuable" or "priceless". "Highly expensive" may refer to something that has a high cost, but it is not equivalent to "invaluable". "Invaluable" implies that something is so valuable that it cannot be measured in terms of money or price. Options A, B, and D are incorrect because they do not accurately represent the meaning of "invaluable" and do not serve as synonyms for the term.

Why the other options are wrong
  • A. "External valuable" is not a correct meaning for "invaluable". "External" refers to something outside of or separate from the thing being described, and does not convey the sense of value or worth.
  • B. "Worthless" is the opposite of "valuable", so it is not a synonym for "invaluable". "Worthless" means having no value or being of no use or importance.
  • D. "Fertile" means capable of producing abundant vegetation or crops, which is not related to the meaning of "invaluable".Therefore, the closest meaning to "invaluable" is "highly valuable" or "priceless", which implies that something is extremely important or useful, and cannot be replaced by anything else.

Q3. Which one is auxiliary?

  • A. With
  • B. One
  • C. Do
  • D. For

Explanation: An auxiliary verb, also known as a helping verb, is used with a main verb to help express the main verb's tense, mood, or voice. In English, common auxiliary verbs include "be," "have," and "do." In this question, "do" is the correct answer because it functions as an auxiliary, especially in forming negatives and questions (e.g., "Do you understand?").The other options are incorrect because they are not auxiliary verbs. "With" and "for" function as prepositions, while "one" is a pronoun, none of which modify verbs.

Why the other options are wrong
  • A. "With" is primarily a preposition, used to express relationships such as association or accompaniment, and is not used to modify verbs, hence it is not an auxiliary verb.
  • B. "One" is a pronoun, often used to refer to a person or thing previously mentioned or easily identified. It does not modify verbs and thus is not an auxiliary verb.
  • D. "For" is a preposition used to indicate purpose, destination, or duration, among other relationships, and does not serve as an auxiliary verb in sentences.

Q4. If You had passed your examination we _ a celebration:

  • A. Would have do
  • B. Must have
  • C. Would have
  • D. Will have

Explanation: The correct answer is Option C:Would have. This phrase is the most appropriate to convey the hypothetical scenario of passing the examination and celebrating. The other options, such as 'Would have do' and 'Will have', are grammatically incorrect or contextually inappropriate for the sentence provided.

Why the other options are wrong
  • A. This option is incorrect. The correct phrase should be 'would have done' in a hypothetical situation like this.
  • B. This option is not suitable as it implies a logical deduction, not a hypothetical condition as presented in the sentence.
  • D. This option is incorrect as it is in the future tense, which does not match the context of the sentence discussing a hypothetical past situation.

Q5. Tell him not _ anyone enter the enclosure:

  • A. To let
  • B. Let
  • C. To have let
  • D. Telling

Explanation: The correct answer is 'Let.' The sentence structure 'Tell him not let anyone enter the enclosure' is a command or directive. In English, after verbs like 'tell,' we use the base form of the verb without 'to' for commands, making 'let' the correct choice. 'To let' is incorrect as it improperly introduces a to-infinitive. 'To have let' suggests a completed action, which does not match the present intent. 'Telling' is a present participle, not suitable for the imperative sentence structure.

Why the other options are wrong
  • A. This option uses an infinitive form, which is incorrect in this context. The sentence requires a bare infinitive 'let' following the verb 'tell.'
  • C. This form is inappropriate because it implies a past perfect action, which does not fit the present directive of the sentence.
  • D. 'Telling' is a present participle and does not fit the command structure required in the sentence.

Q6. He has _ magazine he can lay his hands on:

  • A. Some
  • B. Every
  • C. The
  • D. Any

Explanation: The correct answer is 'Any.' This choice implies that the person can access any magazine without limitations, making it the most appropriate option. The other options, 'Some,' 'Every,' and 'The,' suggest varying levels of access or specificity, which do not align with the context of the question.

Why the other options are wrong
  • A. 'Some' suggests limited access to a certain number of magazines, but not all.
  • B. 'Every' implies access to all magazines, which may not be the case.
  • C. 'The' indicates a specific magazine but does not address access to others.

Q7. When the man failed to answer where _ the police become suspicious:

  • A. Did he belong to
  • B. Was he belonging to
  • C. He belonged to
  • D. He was belonging to

Explanation: The correct answer is 'He belonged to.' This option is the most appropriate as it uses the past tense verb 'belonged' to indicate the man's affiliation or belonging, making the police suspicious. The other options use incorrect verb tenses or structures, making them unsuitable for the sentence.

Why the other options are wrong
  • A. Did he belong to: This option uses the auxiliary verb 'did' to form a question, but it doesn't fit grammatically or semantically in this context.
  • B. Was he belonging to: This option uses the verb 'was' with the gerund 'belonging,' which is not suitable here and sounds awkward.
  • D. He was belonging to: This option, using 'was' with 'belonging,' is not appropriate in this context and sounds unnatural.

Q8. A train is _ different bogeys:

  • A. Made of
  • B. Make up of
  • C. Made with
  • D. Made up of

Explanation: The correct answer is Option D:Made up of. This phrase is the correct usage when describing the composition or structure of something. In this context, we are referring to how the train is composed of different bogeys. The other options, such as "Made of", "Make up of", and "Made with", are incorrect in this context as they do not convey the intended meaning.

Why the other options are wrong
  • A. Made of: This phrase is incorrect in this context. "Made of" is used to describe the material or composition of an object. For example, "The table is made of wood." However, in the case of a train, we are referring to its composition or structure, not the material it is made of.
  • B. Make up of: This phrase is grammatically incorrect. The correct form is "made up of" when referring to the composition or components of something.
  • C. Made with: This phrase is also incorrect in this context. "Made with" is used to describe the ingredients, materials, or tools used in creating something. For example, "The cake is made with flour, eggs, and sugar." However, it does not convey the idea of the train being composed of different bogeys.

Q9. (They) _ had a quarreled about their holiday destination. The word in bracket is:

  • A. An adverb
  • B. An adjective
  • C. An auxiliary
  • D. A pronoun

Explanation: The correct answer is option D: A pronoun. The word in brackets 'They' is a pronoun, specifically the third-person plural subject pronoun. It is used to refer to the group of people who had a quarrel about their holiday destination. The other options, adverb, adjective, and auxiliary, do not accurately describe the word in brackets in the context of the sentence.

Why the other options are wrong
  • A. An adverb is a word that modifies (describes) a verb, which does not fit the context of the sentence. Therefore, this is not the correct answer.
  • B. An adjective is a word that modifies or describes a noun or pronoun, which does not fit the context of the sentence. Therefore, this is not the correct answer.
  • C. Auxiliary verbs (also called helping verbs) are used along with a main verb to express tense, mood, or voice, which does not fit the context of the sentence. Therefore, this is not the correct answer.

Q10. When I got up yesterday, the ground was wet it_

  • A. Has rained
  • B. Was rained
  • C. Had rained
  • D. Rained

Explanation: "Rained" is also a correct option because it is the simple past tense, which is used to describe an action that occurred in the past. The sentence talks about the ground being wet, which implies that it had rained at some point before. Therefore, "rained" is a suitable option.

Why the other options are wrong
  • A. "Has rained" is not a correct option because it is the present perfect tense, which is used to describe an action that occurred at an unspecified time before the present time. However, the sentence talks about an event that occurred in the past, so the present perfect tense is not appropriate.
  • B. "Was rained" is not a correct option because "rained" is an intransitive verb, which means it does not take an object. Therefore, it does not make sense to use the passive voice in this case.
  • C. "Had rained" is a correct option because it is the past perfect tense, which is used to describe an action that occurred before another action in the past. In this case, the ground was wet when the speaker got up, so it can be assumed that it had rained before.

Q11. FORGO is closest in meaning to:

  • A. Run away
  • B. Do without
  • C. Safeguard
  • D. Precede

Explanation: The correct answer is 'Do without.' FORGO means to do without or give up something voluntarily. It does not mean to run away, safeguard, or precede. Choosing 'Do without' best reflects the meaning of FORGO in this context.

Why the other options are wrong
  • A. Run away: This means to flee or escape, which is different from the meaning of 'FORGO.'
  • C. Safeguard: This means to protect or ensure safety, which is not synonymous with 'FORGO.'
  • D. Precede: This means to come before or be prior to something, which is unrelated to 'FORGO.'

Q12. Her brother along with her parents _ that she remain in school.

  • A. Insist
  • B. Insists
  • C. Are insisting
  • D. Were insisting

Explanation: In this sentence, "her brother along with her parents" is a singular subject, so the verb should be in the singular form. "Insists" is the correct verb form for a singular subject, indicating that her brother and her parents collectively insist that she remain in school.

Why the other options are wrong
  • A. Insist is not giving singular sense because it is used with plural.
  • C. Are insisting is giving plural sense.
  • D. Were insisting is also giving a plural sense but the subject is singular.

Q13. A fool and his _ are soon parted:

  • A. Family
  • B. Friends
  • C. Riches
  • D. Money

Explanation: The phrase 'A fool and his _ are soon parted' implies that foolish individuals tend to lose or squander things quickly. The correct answer is 'Money' because it aligns with the idea of a fool losing their money due to poor decisions. The other options, such as 'Family' and 'Friends,' do not directly relate to the concept of losing something due to foolish behavior.

Why the other options are wrong
  • A. Family: While family is important, the phrase doesn't specifically refer to family members being parted from a fool.
  • B. Friends: Similarly, the phrase doesn't specifically mention friends being parted from a fool.
  • C. Riches: This option does not suit the saying. It implies that a fool easily loses their wealth or valuable possessions due to their foolish actions or decisions.

Q14. I've hung out the clothes. It's lovely and sunny: if it _ like this _ dry in two hours.

  • A. Stayed, would be
  • B. Stays, will be
  • C. Had stayed, would have been
  • D. Will stay, will be

Explanation: Therefore, the most appropriate option in the given context is "Stays, will be" as it indicates a general statement about the future outcome based on the continuation of the current sunny weather.Stays, will be: This option indicates a general statement about the future, stating that if the weather stays sunny, the clothes will be dry in two hours. The other options are incorrect because they either refer to past hypothetical situations or make predictions without considering the current sunny weather.

Why the other options are wrong
  • A. Stayed, would be: This option suggests a hypothetical scenario where if the sunny weather stayed, the clothes would be dry in two hours.
  • C. Had stayed, would have been: This option refers to a past hypothetical situation. It implies that if the sunny weather had stayed, the clothes would have been dry in two hours.
  • D. Will stay, will be: This option expresses a certain prediction about the future, stating that if the sunny weather continues, the clothes will be dry in two hours.

Q15. When she came _ senses, she asked to see her son.

  • A. In
  • B. To
  • C. At
  • D. Into

Explanation: Option A (In) is the correct answer. The sentence structure requires the use of the preposition 'in' to indicate the moment when she regained consciousness before asking to see her son. The other options ('To', 'At', 'Into') do not fit the context as well as 'In' does in this sentence.

Why the other options are wrong
  • B. To: This option implies that after becoming conscious, she expressed a desire or made a request to see her son.
  • C. At: This option indicates that upon regaining her senses, she immediately asked or requested to see her son.
  • D. Into: This option suggests that as she regained consciousness, she specifically asked for the purpose of seeing her son.

Q16. The boys got _ the bus at the terminus:

  • A. From
  • B. Of
  • C. Off
  • D. At

Explanation: Therefore, the correct option is 'Off' as it indicates that the boys left the bus at the terminus.Using 'From' would imply the boys started their journey on the bus, 'Of' is incorrect and not commonly used, and 'At' specifies a location but not the action of leaving the bus.

Why the other options are wrong
  • A. From: The use of 'from' in this context implies that the boys started their journey on the bus and got off at the terminus.
  • B. Of: The use of 'of' in this context is incorrect. It does not convey the intended meaning and is not commonly used in this context.
  • D. At: The use of 'at' in this context indicates the specific location where the boys got off the bus, which is the terminus.

Q17. My stay in gilgit will remain _ fond memory to me.

  • A. A
  • B. The
  • C. My
  • D. Any

Explanation: The correct answer is 'My' because the sentence requires a possessive pronoun to indicate ownership. 'My' shows that the memory belongs to the speaker. The other options, such as 'A' and 'The', are articles and do not convey possession. 'Any' is a determiner for singular countable nouns but does not convey possession in this context.

Why the other options are wrong
  • A. The indefinite article (a) is used before a noun that is general or when its identity is not known. In this sentence, a possessive pronoun is required, not an indefinite article.
  • B. The definite article (the) is used before a noun to indicate that the identity of the noun is known to the reader. However, in this sentence, a possessive pronoun is needed, not a definite article.
  • D. 'Any' is used as a determiner for singular countable nouns, but it does not convey the possessive meaning required in this sentence.

Q18. We waited _ dark.

  • A. Beyond
  • B. Before
  • C. Until
  • D. Unless

Explanation: When the sentence says 'We waited until dark,' it means that the waiting was for the darkness to arrive. This indicates a specific time or condition for the waiting. The other options, such as 'Beyond dark' and 'Before dark,' do not capture the intended meaning of waiting for darkness to come. 'Unless dark' also suggests a necessary condition for waiting, but it does not convey the same sense of timing or anticipation as 'Until dark.' Hence, the correct answer is 'Until.'

Why the other options are wrong
  • A. Beyond dark: We waited past the point of darkness, implying that we waited for a longer period than necessary.
  • B. Before dark: We waited prior to the occurrence of darkness, indicating that we did not want to be in the dark.
  • D. Unless dark: We would not wait unless it became dark, suggesting that darkness was a necessary condition for our waiting.

Q19. Interpret

  • A. non_
  • B. un_
  • C. dis_
  • D. mis_

Explanation: When interpreting a word with the prefix "mis-", it implies that something is incorrect or inaccurate. In this context, the word to interpret should convey a sense of error or mistake, making option D the correct choice. Options A, B, and C are incorrect because they do not align with the specific meaning of the prefix "mis-" in this case.

Why the other options are wrong
  • A. The prefix "non-" indicates the absence or negation of something.
  • B. The prefix "un-" indicates the negation or reversal of something.
  • C. The prefix "dis-" indicates the reversal or negation of something.

Q20. All of the following structures are proteinous in nature except:

  • A. Hooves
  • B. Haemoglobin
  • C. Enzymes
  • D. Steroids

Explanation: One major class of lipids is the steroids, which have structures totally different from the other classes of lipids.

Why the other options are wrong
  • A. Option A is wrong because hooves are made up of keratin proteins.
  • B. Option B is wrong because Hemoglobin, in the normal adult, is a protein whose main function is to transport oxygen from the lungs to tissues and to transport carbon dioxide from tissues to the lung
  • C. Option C is wrong because Enzymes are proteins that help speed up metabolism, or the chemical reactions in our bodies. They build some substances and break others down. All living things have enzymes. Our bodies naturally produce enzymes.

Q21. Most favorite host of HIV virus is?

  • A. Lymphocytes
  • B. RBC
  • C. T_Cell
  • D. B_ cells

Explanation: While HIV can infect other types of cells, including monocytes, macrophages, and dendritic cells, it has a particular affinity for T-cells. This is because the virus uses the CD4 receptor on the surface of T-cells to gain entry and infect the cells.

Why the other options are wrong
  • A. The most favorite host of the HIV virus is the T-cell, specifically the CD4+ T-cell. These are a type of white blood cell that plays a crucial role in the immune system by identifying and attacking foreign invaders like viruses and bacteria. The HIV virus targets these cells and uses them as a host to replicate and spread throughout the body.
  • B. Red blood cells (RBCs) do not have the necessary receptors for HIV to infect them, so they are not a host for the virus.
  • D. Similarly, while B-cells are a type of white blood cell that produce antibodies to fight infections, they are not the primary host for the HIV virus. Finally, while lymphocytes are a general term for white blood cells, T-cells and B-cells are specific types of lymphocytes.

Q22. Sunken stomata are found in?

  • A. Mesophytes
  • B. Xerophytes
  • C. Halophytes
  • D. Hydrophytes

Explanation: Sunken stomata are typically found in xerophytes, which are plants adapted to survive in dry, arid environments with limited water availability. These stomata are located in pits or depressions in the epidermis of the plant, which helps to reduce water loss due to evapotranspiration. Xerophytes have evolved various adaptations like thick cuticles and reduced leaf surface area to conserve water. The other options, mesophytes, halophytes, and hydrophytes, are adapted to different environmental conditions and do not typically have sunken stomata.

Why the other options are wrong
  • A. Mesophytes are plants adapted to grow in environments with moderate levels of water availability, and they typically have stomata on the upper leaf surface for efficient gas exchange.
  • C. Halophytes are plants adapted to saline environments, such as salt marshes, and have different adaptations than sunken stomata.
  • D. Hydrophytes are plants adapted to aquatic environments and have stomata on the upper leaf surface for efficient gas exchange in water.

Q23. The mammals terming connecting link between reptilian and mammals?

  • A. Marsupials
  • B. Eutherians
  • C. Monotremes
  • D. Metatherians

Explanation: Monotremes are considered the connecting link between reptiles and mammals because they exhibit both reptilian features, such as laying eggs, and mammalian features, like producing milk to feed their young. The platypus and echidna are examples of living monotremes. Marsupials, eutherians, and metatherians do not share this unique combination of reptilian and mammalian characteristics, making them incorrect answers.

Why the other options are wrong
  • A. Marsupials are a group of mammals that give birth to relatively undeveloped young that complete their development in an external pouch. They are not considered a connecting link between reptiles and mammals.
  • B. Eutherians are placental mammals, which means they have a placenta to nourish the developing fetus. They are the largest group of mammals, but they are not considered a connecting link between reptiles and mammals.
  • D. Metatherians are a group of mammals that give birth to relatively undeveloped young that complete their development in an external pouch, similar to marsupials. They include the marsupials and some extinct mammals, but they are not considered a connecting link between reptiles and mammals.

Q24. In which of the following book lungs are found?

  • A. Clam worm
  • B. Silver Fish
  • C. Leach
  • D. Spider
  • E.

Explanation: book lung, form of respiratory organ found in certain air-breathing arachnid arthropods (scorpions and some spiders).

Why the other options are wrong
  • A. The side flaps are used like gills to help them breathe underwater
  • B. Silver Fish don't have lungs.respire through gills
  • C. Respiration takes place through the skin in the leech, and it is known as cutaneous respiration

Q25. Tissue organization is missing in protozoa and found in:

  • A. Parazoa
  • B. Metazoa
  • C. Sporozoa
  • D. Monera

Explanation: The correct answer is Sporozoa. Protozoa are unicellular organisms that lack tissue level organization, while Sporozoa specifically exhibit protoplasmic level organization without true tissues. Parazoa and Metazoa are multicellular but also lack true tissues, and Monera are primitive unicellular organisms without tissue level organization.

Why the other options are wrong
  • A. Parazoa do not display tissue level organization, they are multicellular but lack true tissues.
  • B. Metazoa also do not have tissue level organization, they have tissues but lack true organ systems.
  • D. Monera are primitive unicellular organisms that lack tissue level organization, they do not have true tissues.

Q26. All of the following are mono nucleotides except:

  • A. AMP
  • B. ATP
  • C. ADP
  • D. FAD

Explanation: A nucleotide is an organic molecule that is composed of a nitrogenous base, a five-carbon sugar, and a phosphate group. A mononucleotide contains only one phosphate group. FAD (flavin adenine dinucleotide) is not a mononucleotide because it contains two nucleotide units (adenine and riboflavin) that are connected by a phosphate group bridge, making it a dinucleotide. This is why FAD is the correct answer, while the other options (AMP, ATP, ADP) are all mononucleotides.

Why the other options are wrong
  • A. AMP (adenosine monophosphate) is a mononucleotide, as it contains one phosphate group.
  • B. ATP (adenosine triphosphate) is a mononucleotide, as it contains one phosphate group.
  • C. ADP (adenosine diphosphate) is a mononucleotide, as it contains one phosphate group.

Q27. The attachment of two subunits of ribosome along mRNA is controlled?

  • A. Sodium ions
  • B. Calcium ions
  • C. Potassium ions
  • D. Magnesium ions

Explanation: The correct answer is Option D: Magnesium ions. Magnesium ions play a crucial role in stabilizing the ribosome-mRNA complex by neutralizing the negative charges of the RNA backbone and facilitating hydrogen bond formation between mRNA and rRNA bases. The other options, sodium, calcium, and potassium ions, do not have a significant role in controlling the attachment of ribosome subunits along mRNA.

Why the other options are wrong
  • A. Sodium ions do not play a significant role in controlling the attachment of ribosome subunits along mRNA. They are mainly involved in regulating the electrochemical potential across cell membranes, muscle contraction, nerve impulses, and other physiological processes.
  • B. Calcium ions do not play a significant role in controlling the attachment of ribosome subunits along mRNA. They are mainly involved in regulating the electrochemical potential across cell membranes, muscle contraction, nerve impulses, and other physiological processes.
  • C. Potassium ions do not play a significant role in controlling the attachment of ribosome subunits along mRNA. They are mainly involved in regulating the electrochemical potential across cell membranes, muscle contraction, nerve impulses, and other physiological processes.

Q28. Proper arrangement of layers in plant cell from inside to outwards is:

  • A. Primary wall _ secondary wall _ middle lamella
  • B. Secondary wall _ primary wall _ middle lamella
  • C. Primary wall _ middle lamella _ secondary wall
  • D. Secondary wall _ middle lamella _ primary wall

Explanation: The correct arrangement of cell wall layers in a plant cell is Secondary wall _ Primary wall _ Middle lamella. The secondary wall is located closest to the protoplast (the living part of the cell), providing structural support. The primary wall surrounds the secondary wall and is flexible, allowing for growth. The middle lamella, which is primarily composed of pectins, is the outermost layer that acts as a glue to hold adjacent plant cells together.In contrast, the other options are incorrect because they misplace the order of the layers. For example, placing the primary wall as the innermost layer or reversing the position of the middle lamella leads to a misunderstanding of the plant cell structure.

Why the other options are wrong
  • A. This option incorrectly places the primary wall as the innermost layer, whereas it is actually the outermost layer. The secondary wall, which is formed after the primary wall, should be next in line before the middle lamella.
  • C. This option incorrectly places the middle lamella between the primary wall and the secondary wall. The middle lamella should be the outermost layer, not positioned between the other layers.
  • D. This option incorrectly suggests that the primary wall is the outermost layer, when it should actually be the middle lamella. The correct order starts with the secondary wall, followed by the primary wall, and then the middle lamella.

Q29. Two parent strands of DNA molecule are:

  • A. Parallel
  • B. Antiparallel
  • C. ……
  • D. None

Explanation: Each strand has a backbone made up of alternating sugars and phosphate groups. The two strands are linked by complementary nitrogenous bases. The strands are oriented in opposite directions, making the structure "antiparallel".

Why the other options are wrong
  • A. They can not be parallel because their direction is 5 to 3 & 3 to 5

Q30. Appendix is vestigial in man but may play role in:

  • A. Digestion
  • B. Excretion
  • C. Immunity
  • D. Movement

Explanation: The appendix has been found to play a role in mammalian mucosal immune function. It is believed to be involved in extrathymically derived T-lymphocytes and B-lymphocyte mediated immune responses and is also said to produce early defenses that help prevent serious infections in humans. Therefore the answer is C.

Why the other options are wrong
  • A. a) Digestion:This option suggests that the appendix may play a role in digestion. This statement is not entirely accurate. While the appendix was previously thought to be a vestigial structure with no significant function in humans, recent research suggests that it may have a minor role in the digestive system. The appendix contains some lymphoid tissue, which could potentially contribute to the body's immune response related to the digestive tract. However, its primary role is not directly involved in digestion.
  • B. b) Excretion:This option states that the appendix may play a role in excretion. This statement is not correct. The appendix is not involved in the excretion of waste products from the body. Excretion primarily occurs through organs like the kidneys and the urinary system, not through the appendix.
  • D. d) Movement:This option states that the appendix may play a role in movement. This statement is not correct. The appendix is not directly involved in movement. It is an organ that is located near the junction of the small intestine and large intestine and does not have a primary function related to movement.

Q31. Ammonia is formed during digestion in:

  • A. Liver
  • B. Stomach
  • C. Small intestine
  • D. Large intestine

Explanation: Ammonia is formed during digestion in the large intestine, specifically the colon, through bacterial fermentation. This process occurs as a result of the breakdown of undigested food residues and metabolic waste, leading to the formation of ammonia. The other options - liver, stomach, and small intestine - do not play a role in the formation of ammonia during digestion.

Why the other options are wrong
  • A. Ammonia is not formed in the liver during digestion. It is actually formed in the intestines through bacterial degradation of nitrogenous waste products.
  • B. The stomach produces hydrochloric acid to aid in food breakdown, but it does not play a role in ammonia formation.
  • C. The small intestine absorbs nutrients but is not a site for ammonia formation.

Q32. Cloned dolly was identical to the:

  • A. Parents who gestated and gave birth to Dolly
  • B. Parents, who donated egg cell
  • C. Parent, who donated somatic cell
  • D. Both b and c

Explanation: The correct answer is Option D: Both b and c. Dolly, the cloned sheep, was identical to the sheep whose somatic cell was used for cloning (Parent who donated somatic cell) and the sheep whose egg cell was used for cytoplasmic and mitochondrial DNA (Parents, who donated egg cell). This combination of genetic material resulted in Dolly being a clone of the original sheep.Options A and C are incorrect because Dolly's genetic material did not come from the parents who gestated or gave birth to her, or from the parent who donated the egg cell.

Why the other options are wrong
  • A. Parents who gestated and gave birth to Dolly: Dolly was carried to term by a surrogate mother and was not genetically related to her.
  • B. Parents, who donated egg cell: Dolly's cytoplasmic and mitochondrial DNA came from the egg cell of another sheep that donated the egg cell.
  • C. Parent who donated somatic cell: Dolly's genetic material came from the nucleus of an adult somatic cell from one sheep, which was used to create the clone.

Q33. Cleavage differ from mitosis in that:

  • A. It occurs only in zygote
  • B. It occurs in all body cells
  • C. It results in haploid cells only
  • D. It results in identical cells

Explanation: Cytokinesis during cleavage results in identical cells as the parent cell divides into two daughter cells. The other options are incorrect as cleavage is not limited to the zygote stage, does not occur in all body cells, and does not result in haploid cells.

Why the other options are wrong
  • A. This option is incorrect because cleavage is not limited to the zygote stage but continues as the embryo develops.
  • B. This option is incorrect as cleavage is specific to the early stages of embryonic development, not all body cells.
  • C. Cleavage involves mitosis, maintaining the diploid chromosome number, and does not result in haploid cells.

Q34. RBC's are destroyed in liver while WBC's are destroyed in:

  • A. Plasma
  • B. Liver
  • C. Inside various cells of body
  • D. Outside the blood stream

Explanation: White blood cells are destroyed inside various cells of the body, where they encounter and destroy foreign substances through mechanisms like phagocytosis. This process is crucial for immune response and defense against pathogens. RBCs, on the other hand, are primarily destroyed in the liver where they are broken down and recycled. Option C is the correct answer as it accurately describes the destruction location of WBCs. Option D is not as precise as it focuses on the movement of WBCs outside the bloodstream, which is a part of their immune response but not the primary location of destruction.

Why the other options are wrong
  • A. Plasma is the liquid component of blood that carries blood cells, nutrients, hormones, and waste products. While plasma plays a crucial role in transporting substances, it does not actively participate in the destruction of RBCs or WBCs.
  • B. The liver is responsible for the breakdown and recycling of old or damaged red blood cells. As RBCs age or become damaged, they are engulfed and broken down by specialized cells in the liver called Kupffer cells.
  • D. White blood cells can leave the bloodstream and move into tissues where infection or inflammation is present. This process allows WBCs to reach the site of infection or injury more effectively.

Q35. Condensation of chromosome reaches to its peak during early:

  • A. Prophase
  • B. Metaphase
  • C. Anaphase
  • D. Telophase

Explanation: The correct answer is Prophase. This stage initiates the condensation of chromosomes, reaching their maximum compaction. Metaphase, Anaphase, and Telophase do not represent the peak condensation phase of chromosomes in the cell cycle.

Why the other options are wrong
  • B. Metaphase is incorrect. While chromosomes are aligned in this stage, their condensation does not reach its peak.
  • C. Anaphase is incorrect. Chromosomes become less condensed and elongated during this stage as they separate.
  • D. Telophase is incorrect. Chromosomes start to decondense in this final stage of mitosis or meiosis.

Q36. The enzyme "reverse transcriptase" present in HIV virus is:

  • A. 50 molecules per virion
  • B. 40 molecules per virion
  • C. 30 molecules per virion
  • D. 20 molecules per virion

Explanation: In summary, the specific number of reverse transcriptase molecules per HIV virion can vary due to factors like viral strain and infection stage. While options from 20 to 50 molecules per virion are feasible, the actual quantity is not definitively established. Option A, with 50 molecules per virion, is considered the most suitable answer here because it falls within the possible range of values despite variability in the actual count.

Why the other options are wrong
  • B. 40 molecules per virion: This option suggests that there are 40 reverse transcriptase molecules per HIV virion. Similar to the previous option, the actual number can vary and may not be the definitive quantity.
  • C. 30 molecules per virion: This option proposes that there are 30 reverse transcriptase molecules present in each HIV virion. The number of molecules can differ, and 30 molecules per virion is a plausible value.
  • D. 20 molecules per virion: This option suggests that there are 20 reverse transcriptase molecules per HIV virion. While this could be a possible quantity, it may not be the average or most common count, and variability exists in the actual number.

Q37. All of the following are carbohydrate EXCEPT:

  • A. Glycogen
  • B. Collagen
  • C. Starch
  • D. Cellulose

Explanation: The correct answer is Option B: Collagen. Collagen is a protein, not a carbohydrate, and is essential for the structure and strength of various tissues in the body. Glycogen (Option A), Starch (Option C), and Cellulose (Option D) are all carbohydrates with distinct functions in energy storage (Glycogen), food sources (Starch), and plant cell structure (Cellulose) respectively.

Why the other options are wrong
  • A. Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria
  • C. Starchy foods are our main source of carbohydrates.
  • D. Cellulose, a fibrous carbohydrate found in all plants, is the structural component of plant cell walls.

Q38. The amount of bile produced by human liver is:

  • A. 1000ml/day
  • B. 2000ml/day
  • C. 3000ml/day
  • D. 4000ml/day

Explanation: 1000ml/day: In a normal person, the liver produces between 800 to 1,000 milliliters of bile each day. This option falls within the plausible range of average daily bile production. While bile production can vary between individuals, this range is generally accepted. The other options suggesting higher volumes of bile production (2000ml/day, 3000ml/day, 4000ml/day) are incorrect as they exceed the typical daily production rates and are unlikely under normal circumstances.

Why the other options are wrong
  • B. 2000ml/day: This option suggests that the human liver produces 2000 milliliters (2 liters) of bile per day. This volume is higher than what is typically observed for daily bile production. The liver's ability to produce such a large amount of bile in a single day is unlikely under normal circumstances.
  • C. 3000ml/day: This option proposes that the human liver produces 3000 milliliters (3 liters) of bile per day. Similar to the previous option, this volume is significantly higher than what is generally observed for daily bile production. Bile production of this magnitude is highly unlikely in a healthy individual.
  • D. 4000ml/day: This option suggests that the human liver produces 4000 milliliters (4 liters) of bile per day. Producing such a large volume of bile in a single day is highly improbable and not consistent with typical bile production rates.

Q39. Daphnia belongs to:

  • A. Insecta
  • B. Annelida
  • C. Crustacean
  • D. Arachinda

Explanation: Crustacean: This is the correct option. Daphnia belongs to the class Crustacea within the phylum Arthropoda. Crustaceans include various aquatic arthropods, such as crabs, lobsters, shrimp, and Daphnia, commonly known as water fleas. The other options are incorrect because Daphnia is not an insect (Option A), segmented worm (Option B), or arachnid (Option D). It is specifically classified as a crustacean within the phylum Arthropoda.

Why the other options are wrong
  • A. Insecta: Insecta refers to the class of insects, which is a separate class within the phylum Arthropoda. While insects share some similarities with crustaceans, such as jointed legs and exoskeletons, Daphnia does not belong to the class Insecta. Instead, it belongs to the class Crustacea.
  • B. Annelida: Annelida is the phylum of segmented worms, such as earthworms and leeches. Daphnia does not belong to this phylum, as it is not a segmented worm but rather a member of the phylum Arthropoda.
  • D. Arachnida: Arachnida is the class of arthropods that includes spiders, scorpions, ticks, and mites. Daphnia does not belong to this class. While both crustaceans and arachnids are arthropods, they belong to different classes within the phylum Arthropoda.

Q40. Changes in gene frequencies in small population by chance is called:

  • A. Gene pool
  • B. Genetic drift
  • C. Gene mutation
  • D. Gene flow

Explanation: Genetic drift is a mechanism of evolution, it refers to random fluctuations in the frequencies of alleles from generation to generation due to chance of events, therefore the answer will be B.

Why the other options are wrong
  • A. The total aggregate of genes in a population at any one time is called the population’s gene pool. It consists of all alleles at all gene loci in all individuals of the population.
  • C. A genetic mutation is a change to a gene's DNA sequence to produce something different. It creates a permanent change to that gene's DNA sequence.
  • D. Gene flow — also called migration — is any movement of individuals, and/or the genetic material they carry, from one population to another.

Q41. Feathers of birds are water proof due to secretion of?

  • A. Sudoriferous glands
  • B. Endocrine glands
  • C. Preen gland
  • D. Thymus glands

Explanation: The correct answer is the preen gland. Birds use the preen oil secreted by the uropygial gland to waterproof their feathers. This oil helps maintain the integrity of the feathers and protects them from getting soaked, allowing birds to stay dry and maintain their ability to fly effectively. The other options, sudoriferous glands, endocrine glands, and thymus glands, do not play a role in waterproofing feathers.

Why the other options are wrong
  • A. Sudoriferous glands respond by secreting sweat, but they are not responsible for waterproofing feathers.
  • B. Endocrine glands release hormones into the bloodstream, but they do not help in waterproofing feathers.
  • D. Thymus gland makes white blood cells (T lymphocytes) which are part of the immune system and help fight infection, but they are not involved in waterproofing feathers.

Q42. In fishes, the heart pumps:

  • A. Pure blood to body
  • B. Impure blood to body
  • C. Pure blood to gills
  • D. Impure blood to gills

Explanation: In fishes, the heart pumps out deoxygenated blood from the body to the gills where it gets oxygenated. The correct answer is 'Impure blood to gills' because fishes have a two-circuit circulatory system that carries deoxygenated blood to the gills for oxygenation before returning it to the body.The other options are incorrect because fishes do not pump pure blood to the body or pure blood to the gills in their circulatory system.

Why the other options are wrong
  • A. Pure blood to body: The heart pumps oxygenated blood from the gills to the body of the fish, delivering oxygen and nutrients to the tissues.
  • B. Impure blood to body: Fishes have a two-chambered heart, and it pumps deoxygenated blood from the body to the gills for oxygenation.
  • C. Pure blood to gills: Fishes with a single circuit circulatory system pump deoxygenated blood from the body to the gills to be oxygenated.

Q43. The size of ribosome in prokaryotic cell is:

  • A. 40S
  • B. 60S
  • C. 70S
  • D. 80S

Explanation: 70S: This option is correct because prokaryotic cells have ribosomes made up of a small 30S subunit and a large 50S subunit, totaling 70S. The other options are incorrect because the 40S and 60S ribosomes are found in eukaryotic cells, while the 80S ribosome is also specific to eukaryotes.

Why the other options are wrong
  • A. 40S: This option is incorrect. The 40S ribosome is found in eukaryotic cells, not prokaryotic cells.
  • B. 60S: This option is incorrect. The 60S ribosome is also found in eukaryotic cells, not prokaryotic cells.
  • D. 80S: This option is incorrect. The 80S ribosome is found in eukaryotes.

Q44. The molecular formula of chlorophyll b is:

  • A. C55H70O6N4Mg
  • B. C70H55O11N5Mg4
  • C. C14H55O6N5Mg3
  • D. C55H76O5N6Mg2

Explanation: The correct molecular formula of chlorophyll b is C55H70O6N4Mg. This formula indicates the presence of 55 carbon atoms, 70 hydrogen atoms, 6 oxygen atoms, 4 nitrogen atoms, and 1 magnesium atom. Option A is correct because it aligns with this molecular formula. Options B, C, and D have incorrect combinations of elements and quantities, making them incorrect choices for the molecular formula of chlorophyll b.

Why the other options are wrong
  • B. C70H55O11N5Mg4: This option is incorrect. The given formula does not correspond to the molecular formula of chlorophyll b.
  • C. C14H55O6N5Mg3: This option is incorrect. The given formula has a significantly lower number of carbon and hydrogen atoms compared to the molecular formula of chlorophyll b.
  • D. C55H76O5N6Mg2: This option is incorrect. The given formula has an excess number of hydrogen atoms compared to the molecular formula of chlorophyll b.

Q45. Which of the following is sedentary in adult and active in larval stage?

  • A. Sponge
  • B. Leech
  • C. Salamander
  • D. Grasshopper

Explanation: The correct answer is Sponge. Sponges have a sedentary adult stage where they are attached to a substratum, while their larval stages (Amphiblastula and Parenchymula) are free-living and active. Leeches, salamanders, and grasshoppers are all active in both their adult and larval stages, making them incorrect choices for this question.

Why the other options are wrong
  • B. Leech: Leeches are active organisms in both adult and larval stages. They can move and actively seek out hosts for feeding.
  • C. Salamander: Salamanders are generally active organisms in both adult and larval stages. They have the ability to move and exhibit various locomotor behaviors.
  • D. Grasshopper: Grasshoppers are active organisms in both adult and larval stages. They have well-developed legs and are capable of hopping and flying to move around in search of food and mates.

Q46. The primers used in polymerase chain reaction has a sequence of bases

  • A. 8
  • B. 12
  • C. 16
  • D. 20

Explanation: Primers in PCR are typically designed to be 18-22 bases long. This length allows them to bind specifically to the target DNA sequence, providing both high specificity and efficiency at the annealing temperature. Options A, B, and C (8, 12, and 16 bases, respectively) are generally too short to offer the necessary specificity and might lead to non-specific binding or inefficient amplification. Therefore, option D, 20 bases, is the correct choice as it falls within the optimal range for PCR primer design.

Why the other options are wrong
  • A. Primers with only 8 bases are generally too short to ensure specific binding in PCR. They lack the length needed for adequate specificity.
  • B. While 12 bases can offer some specificity, it is generally insufficient for PCR, where longer primers are preferred to ensure correct annealing to the target DNA.
  • C. Primers with 16 bases are closer to the optimal length but might still fall short of the usual range used for high specificity and efficiency in PCR.

Q47. The valve between left atrium and left ventricle is :

  • A. Semi lunar valve
  • B. Tricuspid valve
  • C. Pulmonary valve
  • D. Bicuspid valve

Explanation: The bicuspid valve, also known as the mitral valve, is the correct answer because it is located between the left atrium and left ventricle, allowing blood flow in one direction. The other options are incorrect because they are located between different chambers of the heart, not the left atrium and left ventricle.

Why the other options are wrong
  • A. Semi-lunar valve: Semi-lunar valves are located between the ventricles and the major arteries (aorta and pulmonary artery), not between the atrium and ventricle.
  • B. Tricuspid valve: The tricuspid valve is located between the right atrium and right ventricle, not between the left atrium and left ventricle.
  • C. Pulmonary valve: The pulmonary valve is situated between the right ventricle and the pulmonary artery, not between the left atrium and left ventricle.

Q48. Cup_like ascocarp in fungi is:

  • A. Apothecium
  • B. Perithecium
  • C. Hysterothylacium
  • D. Cleistothecium

Explanation: The correct answer is Apothecium. An apothecium is a cup-shaped ascocarp with an exposed hymenium. This structure fits the description of a cup-like ascocarp in fungi, making it the correct choice. Perithecium, Hysterothylacium, and Cleistothecium are all different types of ascocarps, but they do not match the specific cup-like morphology mentioned in the question.

Why the other options are wrong
  • B. A perithecium is a flask-shaped ascocarp with a small opening. While it is a type of ascocarp, it does not match the description of a cup-like structure.
  • C. A hysterothylacium is a flask-shaped ascocarp with a longitudinal opening. This structure differs from a cup-like ascocarp.
  • D. A cleistothecium is a closed, spherical ascocarp that ruptures to release spores. While it is an ascocarp, it does not resemble a cup-like structure.

Q49. Each molecule of NADH2 entering the electron transport chain produces:

  • A. Four ATPs
  • B. Two ATPs
  • C. One ATP
  • D. Three ATPs

Explanation: Three ATPs: This is the correct option. Each NADH molecule generally leads to the synthesis of around three ATP molecules in the electron transport chain. However, the exact ATP yield can vary based on cellular conditions and ATP production efficiency. Therefore, each NADH molecule typically results in the production of approximately three ATP molecules. Options A, B, and C are incorrect because NADH does not directly produce four, two, or one ATPs, respectively.

Why the other options are wrong
  • A. Four ATPs: This option is incorrect. While NADH contributes to ATP production, it does not directly produce four ATPs.
  • B. Two ATPs: This option is also incorrect. While NADH is involved in ATP synthesis, it does not directly yield two ATPs.
  • C. One ATP: This option is incorrect as well. NADH is crucial for ATP production, but it does not directly produce only one ATP.

Q50. A coiled haemoglobin is called:

  • A. Haemocyonin
  • B. Haemoprotein
  • C. Myoglobin
  • D. Haemorrhoids

Explanation: A coiled haemoglobin is referred to as 'Haemoprotein' because haemoglobin is a type of haemoprotein. Haemoprotein is a general term for proteins containing a heme group, which includes haemoglobin and other oxygen-binding proteins. The other options are incorrect because they either refer to different proteins (haemocyanin and myoglobin) or a medical condition unrelated to haemoglobin (haemorrhoids).

Why the other options are wrong
  • A. Haemocyanin is a copper-containing protein found in some invertebrates, not related to haemoglobin.
  • C. Myoglobin is a single-chain globular protein found in muscle cells, responsible for oxygen storage within muscle tissues.
  • D. Haemorrhoids are swollen blood vessels in the rectum or anus, unrelated to haemoglobin.

Q51. In chromosome, the material controlling heredity is:

  • A. Histone
  • B. RNA
  • C. DNA
  • D. All of the above

Explanation: The material controlling heredity in chromosomes is DNA. DNA carries genetic information and directly influences hereditary traits in organisms. Histones are involved in DNA packaging, RNA plays roles in gene expression, but only DNA serves as the primary material controlling heredity.

Why the other options are wrong
  • A. Histones are proteins involved in DNA organization, but they do not directly control heredity.
  • B. RNA molecules have roles in gene expression but are not the primary material controlling heredity.
  • D. This option is incorrect because histones and RNA do not directly control heredity, only DNA does.

Q52. If father of a baby is hemophilic and mother is a carrier then chances if the baby inheriting the disease will be:

  • A. 0%
  • B. 50%
  • C. 75%
  • D. 100%

Explanation: If the father is hemophilic (has the disease) and the mother is a carrier, the chances of the baby inheriting the disease will be 50%. This is because there is a 50% chance that the baby will inherit the hemophilia gene from the father. Therefore, the correct option is '50%' as there is a 50% chance of the baby inheriting the hemophilia gene and having the disease in this particular situation. Options 0%, 75%, and 100% are incorrect as they do not accurately represent the genetic inheritance patterns of hemophilia in this scenario.

Why the other options are wrong
  • A. 0%: Hemophilia is an inherited genetic disorder, and there is a possibility of the baby inheriting the disease. Therefore, this option is incorrect.
  • C. 75%: The chances of inheriting hemophilia are not as high as 75% in this scenario. Hence, this option is incorrect.
  • D. 100%: While there is a high likelihood of inheriting the disease, it is not guaranteed to be 100%. Therefore, this option is incorrect.

Q53. First crystalline hormone is:

  • A. Thyroxine
  • B. Non_adrenaline
  • C. Adrenaline
  • D. All of above

Explanation: Thyroxine: Thyroxine was the first hormone to be isolated and crystallized in 1914, making it a significant milestone in endocrinology. This historical fact makes it the correct answer to this question. Non-adrenaline and adrenaline are not crystalline hormones, so they are incorrect choices. The option 'All of above' is also incorrect because not all options listed are correct.

Why the other options are wrong
  • B. Non-adrenaline: Non-adrenaline is not a hormone, so it cannot be the first crystalline hormone.
  • C. Adrenaline: Although adrenaline is a well-known hormone, it was not the first one to be isolated and crystallized.
  • D. This option is incorrect because not all the options mentioned are valid crystalline hormones. Only Thyroxine fits the criteria.

Q54. A pollen _ grain germinates and develops into :

  • A. Prothallus
  • B. Saprophyte
  • C. Micro gametophyte
  • D. Mega gametophyte

Explanation: When a pollen grain germinates, it develops into a micro gametophyte, which carries the male gametes (sperm cells) for fertilization. Therefore, the correct option is 'Micro gametophyte' as it directly relates to the development of pollen grains. The other options, Prothallus, Saprophyte, and Mega gametophyte, are incorrect because they do not represent the specific structure that pollen grains develop into during plant reproduction.

Why the other options are wrong
  • A. Prothallus: This option is incorrect. Prothallus refers to the gametophyte stage in ferns, not the development of a pollen grain.
  • B. Saprophyte: This option is incorrect. Saprophytes obtain nutrients from decaying organic matter and are not directly related to the development of pollen grains.
  • D. Mega gametophyte: This option is incorrect. The mega gametophyte is the female gametophyte in plants and is not directly related to the development of pollen grains.

Q55. All of the following belongs to mosses Except:

  • A. Funaria
  • B. Polytrichum
  • C. Sphagnum
  • D. Club mosses

Explanation: Club mosses, also known as Lycopodiopsida or Lycophytes, are a distinct group of plants that are not classified as mosses. They belong to the Lycopodiaceae family. Therefore, the correct option is 'Club mosses' as it is not a member of the mosses group. Funaria, Polytrichum, and Sphagnum are all genera of true mosses, while Club mosses belong to a different group.

Why the other options are wrong
  • A. Funaria: Funaria is a genus of mosses commonly known as cord mosses.
  • B. Polytrichum: Polytrichum is a genus of mosses, commonly known as haircap mosses.
  • C. Sphagnum: Sphagnum refers to a genus of mosses, commonly known as peat mosses.

Q56. Alveoli are absent in:

  • A. Fishes
  • B. Amphibians
  • C. Birds
  • D. Mammals

Explanation: Alveoli, small air sacs in the lungs where gas exchange occurs, are present in fishes. Fishes rely on gills rather than alveoli in their lungs for respiration, making them the correct answer. Amphibians, birds, and mammals all have alveoli in their lungs for gas exchange, so they are not the correct answers for this question.

Why the other options are wrong
  • B. Amphibians: This option is incorrect. While amphibians have simpler lungs compared to mammals, they do possess alveoli for gas exchange.
  • C. Birds: This option is incorrect. Birds have well-developed lungs with numerous air sacs and alveoli.
  • D. Mammals: This option is incorrect. Mammals have highly specialized lungs with millions of alveoli for efficient gas exchange.

Q57. Which one is isotonic with surrounding sea water?

  • A. Bony Fishes
  • B. Shark
  • C. Carp
  • D. Paramecium

Explanation: Sharks are isotonic with sea water, meaning their body fluids have the same concentration of dissolved substances as the water. This allows them to maintain water balance easily. Bony fishes are hypotonic, needing to regulate their salt concentration. Carps are hypertonic in freshwater, while Paramecium is hypotonic due to lower solute concentration in the environment.

Why the other options are wrong
  • A. Bony Fishes: This option is incorrect. Bony fishes are not isotonic with sea water. They are hypotonic and must actively regulate their body salt concentration to prevent dehydration and maintain osmotic balance.
  • C. Carp: Carps are fresh water fish. In freshwater, a fish is hypertonic to its environment, meaning the fish is 'more salty' and water continually flows into the fish's body via osmosis.
  • D. Paramecium is hypotonic, meaning that the water surrounding the paramecium is lower in solute concentration, making it hypotonic.

Q58. Sperms of which animal can remain viable for years within the female genital tract?

  • A. Whale
  • B. Bat
  • C. Camel
  • D. Giraffe

Explanation: In most mammals, sperm is capable of fertilizing eggs for only a few days after copulation. Female bats have the ability to store sperm for extended periods, ranging from several months to even years, making them the correct answer in this context. Whales, camels, and giraffes do not exhibit the same level of sperm viability within the female genital tract as bats do.

Why the other options are wrong
  • A. Whales have the ability for sperm to remain viable in the female genital tract for an extended period of time, but not for years as in the correct option.
  • C. Camels have unique reproductive mechanisms for arid environments, but their sperm viability within the female genital tract is not known to last for years.
  • D. Giraffes have unique reproductive characteristics, but their sperm viability within the female genital tract is not known to be exceptionally long-lasting.

Q59. Opossum belongs to:

  • A. Metatheria
  • B. Eutheria
  • C. Theria
  • D. Prototheria

Explanation: Metatheria: Opossum belongs to the Metatheria, also known as marsupials. Marsupials are a group of mammals that give birth to relatively undeveloped young, which then complete their development in a pouch.Therefore, the correct option for opossum is 'Metatheria' as they belong to the marsupial group within the category of Theria. Eutheria, Theria, and Prototheria do not apply to opossums based on their classification characteristics.

Why the other options are wrong
  • B. Eutheria: Eutheria refers to placental mammals. Opossums are not placental mammals; therefore, they do not belong to this group.
  • C. Theria: Theria includes both marsupials (Metatheria) and placental mammals (Eutheria). Since opossums are marsupials, they fall under the category of Theria.
  • D. Prototheria: Prototheria refers to the group of monotremes, which are egg-laying mammals. Opossums are not monotremes; hence, they do not belong to this category.

Q60. Wheat, maize and rice are the member of family:

  • A. Fabaceae
  • B. Solanaceae
  • C. Poaceae
  • D. Mimosaceae

Explanation: The correct answer is Poaceae. Wheat, maize, and rice belong to the Poaceae family, commonly known as the grass family, due to their similar characteristics such as grass-like appearance, parallel-veined leaves, and small flowers in spikelets. The other options are incorrect because they belong to different plant families with distinct characteristics that do not include wheat, maize, or rice.

Why the other options are wrong
  • A. Fabaceae: This family includes plants like peas and beans, but not wheat, maize, or rice. Members of the Fabaceae family have characteristic pea-like flowers and produce pods.
  • B. Solanaceae: This family includes plants like tomatoes, potatoes, and peppers, but not wheat, maize, or rice. Members of the Solanaceae family have characteristic tubular flowers and often produce berries or capsules.
  • D. Mimosaceae: This family includes plants like acacia and mimosa, but not wheat, maize, or rice. Members of the Mimosaceae family have characteristic feathery leaves and often produce spherical flower heads.

Q61. Growth movement of pollen tube towards the egg is:

  • A. Hydrotropism
  • B. Chemotropism
  • C. Chemotactic
  • D. Seismetactic

Explanation: Chemotropism: Chemotropism is the growth movement of a plant part towards or away from a chemical stimulus. In the context of a pollen tube, it can refer to the growth movement towards the chemical signals released by the egg.Therefore, the most appropriate option for the growth movement of a pollen tube towards the egg is 'Chemotropism,' as it involves the growth response towards the chemical signals released by the egg.

Why the other options are wrong
  • A. Hydrotropism: Hydrotropism is the growth movement of plant roots in response to water. It is not applicable to the growth movement of a pollen tube towards the egg.
  • C. Chemotactic: Chemotaxis is the directed movement of an organism or cell towards or away from a chemical substance. It is applicable to the growth movement of a pollen tube towards the chemical signals released by the egg.
  • D. Seismetactic: There is no widely recognized term called 'seismetactic' in the context of plant growth or movement.

Q62. All of the following are characteristics of enzymes except:

  • A. They increase the activation energy
  • B. They are specific in action
  • C. They possess specific active site
  • D. They possess dimensional shapes

Explanation: They increase the activation energy: This statement is incorrect. Enzymes actually decrease the activation energy required for a chemical reaction to occur, making the reaction more favorable and speeding up the rate of the reaction. Therefore, the incorrect statement among the options is "They increase the activation energy." Enzymes actually lower the activation energy of reactions, allowing them to occur more readily.

Why the other options are wrong
  • B. They are specific in action: This statement is correct. Enzymes are highly specific in their action and typically catalyze specific reactions or types of reactions.
  • C. They possess specific active sites: This statement is correct. Enzymes have specific regions called active sites where substrates bind and undergo the catalytic reaction.
  • D. They possess dimensional shapes: This statement is incorrect. Enzymes do possess specific three-dimensional shapes, often referred to as their tertiary structure, which is crucial for their function and interaction with substrates.

Q63. Beside mammals, diaphram is also present in:

  • A. Birds
  • B. Crocodiles
  • C. Fishes
  • D. Toads

Explanation: Correct Answer: BirdsThe presence of a diaphragm in birds allows for effective respiration by assisting in lung function. While birds have this structure, crocodiles, fishes, and toads do not possess a diaphragm. Crocodiles rely on organ movement, fishes use gills, and toads employ skin and lung respiration methods.

Why the other options are wrong
  • B. Crocodiles: Unlike birds, crocodiles do not have a diaphragm. They rely on the movement of their organs for inhalation.
  • C. Fishes: Fishes do not possess a diaphragm. Their respiration is reliant on gills to extract oxygen from water.
  • D. Toads: Toads, similar to fishes, do not have a diaphragm. They primarily respire through their skin and lungs.

Q64. Metamerism is found in:

  • A. Earth worm
  • B. Sponges
  • C. Snakes
  • D. Grass Hopper

Explanation: Metamerism is the repetition of homologous body segments. This type of development can be seen in the Annelids, which include earthworms, leeches, tubeworms, and their relatives. It is also seen in a more advanced form in the Arthropods, such as crustaceans, insects.Earthworms exhibit metamerism with distinct segments along their body, allowing for efficient movement and specialized functions in each segment. Sponges, snakes, and grasshoppers do not exhibit metamerism, making them incorrect choices for this question.

Why the other options are wrong
  • B. Sponges: Sponges do not exhibit metamerism. They have a simple body structure without distinct repeating segments.
  • C. Snakes: Snakes do not exhibit metamerism. They have a long, flexible body without distinct segments.
  • D. Grasshopper: Grasshoppers do not exhibit metamerism with distinct body segments, including the head, thorax, and abdomen, each performing specific functions in locomotion and digestion.

Q65. Early blight of potato is caused by:

  • A. Alternaria_solani
  • B. Phytophthora_infestans
  • C. Erysiphe_graminls
  • D. Claviceps_purpurea

Explanation: Alternaria solani is the correct answer as it is the fungal pathogen responsible for early blight of potato, causing specific symptoms on potato plants. The other options, such as Phytophthora infestans, Erysiphe graminis, and Claviceps purpurea, are pathogens that affect different plants and do not cause early blight in potatoes.

Why the other options are wrong
  • B. Phytophthora infestans is the causal agent of late blight of potato, primarily affecting foliage with wilting, browning, and decay.
  • C. Erysiphe graminis causes powdery mildew in grasses and cereals, not specific to potato plants.
  • D. Claviceps purpurea causes ergot disease in cereals and grasses, not related to potato plants.

Q66. Which one among the following possess a double ringed structure?

  • A. Cytosine
  • B. Adenine
  • C. Uracil
  • D. Thymine

Explanation: Purines, such as adenine and guanine, have a double-ringed structure - one hexagonal pyrimidine ring and an imidazole ring. Adenine is the correct option as it belongs to purines. Cytosine, uracil, and thymine are all single-ringed pyrimidines, making them incorrect options.

Why the other options are wrong
  • A. Cytosine is a single-ringed pyrimidine, not double-ringed.
  • C. Uracil is a single-ringed pyrimidine found in RNA, not double-ringed.
  • D. Thymine is also a single-ringed pyrimidine, not double-ringed.

Q67. Which of the following are the pioneer group to develop true roots and true leaves,

  • A. Psilopsida
  • B. Sphenopsida
  • C. Pteropsida
  • D. Lycopsida

Explanation: Among the options given, the pioneer group to develop true roots and true leaves is Pteropsida.Pteropsida: This group includes ferns, which have true roots, stems, and leaves, making them the pioneers in developing all three structures.Therefore, Pteropsida is the correct option as it represents the group that has true roots and true leaves. Psilopsida lacks true roots and leaves, Sphenopsida has reduced and scale-like leaves, and Lycopsida has small and scale-like leaves as well.

Why the other options are wrong
  • A. Psilopsida: These plants, such as whisk ferns, lack true roots and leaves, and instead have simple photosynthetic stems.
  • B. Sphenopsida: These plants, including horsetails, have true roots and stems, but their leaves are reduced and scale-like.
  • D. Lycopsida: Lycophytes, like club mosses, have true roots and leaves, but their leaves are small and scale-like, similar to Sphenopsida.

Q68. An enzyme in gastric juice of many infant mammals that precipitates milk protein is:

  • A. Renin
  • B. Personage
  • C. Rennin
  • D. Gastrin

Explanation: Rennin, also known as chymosin, is the correct answer. It is an enzyme found in the gastric juice of many infant mammals, including humans, that helps in the digestion of milk protein by coagulating it. The other options are incorrect because 'Renin' is a misspelling of the correct enzyme 'Rennin', 'Personage' is not a relevant enzyme, and 'Gastrin' is a hormone, not an enzyme involved in milk protein digestion.

Why the other options are wrong
  • A. Renin: Renin is an enzyme found in the gastric juice of many infant mammals, including humans. It plays a crucial role in the digestion of milk protein by causing its precipitation and curdling, which aids in the digestion process.
  • B. Personage: There is no specific enzyme called 'personage' related to the digestion of milk protein. It seems to be a misspelling or incorrect term.
  • D. Gastrin: Gastrin is not an enzyme involved in the digestion of milk protein. It is a hormone produced in the stomach that regulates the secretion of gastric acid and stimulates gastric motility.

Q69. Nematocyst are found in:

  • A. Nematodes
  • B. Coelenterates
  • C. Annelids
  • D. Sponges

Explanation: Nematocysts are specialized structures found in coelenterates, which are multicellular aquatic animals living in colonies. These structures serve the purpose of capturing prey and defense. The other options, nematodes, annelids, and sponges, do not possess nematocysts and have different mechanisms for feeding and defense.

Why the other options are wrong
  • A. Nematodes, also known as roundworms, are a separate phylum of animals that are not related to cnidarians. They do not have nematocysts. The nematocysts of cnidoblasts, also known as cnidocytes.
  • C. Annelids, also known as segmented worms, are another phylum of animals that do not have nematocysts. They may have other specialized structures for feeding and defense, but not nematocysts.
  • D. Sponges, which belong to the phylum Porifera, do not have nematocysts either. They have a different type of specialized cells called choanocytes, which are involved in feeding and water circulation.

Q70. Extract embryonic membrane like amnion and chorine appeared for the first time:

  • A. Amphibians
  • B. Reptiles
  • C. Birds
  • D. Fish

Explanation: Embryonic membranes like the amnion and chorion first appeared in reptiles, making option B the correct answer. These membranes are part of the amniotic egg, a key adaptation that allowed reptiles to reproduce on land. Birds also have similar adaptations, but they evolved from reptilian ancestors, not the other way around. Options A, C, and D are incorrect because they do not align with the evolutionary development of embryonic membranes in animals.

Why the other options are wrong
  • A. Amphibians typically do not have amniotic eggs or well-developed embryonic membranes like the amnion and chorion.
  • C. Birds have amniotic eggs with embryonic membranes, but they evolved from reptilian ancestors who first developed these adaptations.
  • D. Fish do not have amniotic eggs or the specific embryonic membranes mentioned in the question.

Q71. Which one of the following animals possesses an open circulatory system:

  • A. Amoeba
  • B. Earthworm
  • C. Grasshopper
  • D. Man

Explanation: Among the options provided, the animal that possesses an open circulatory system is the Grasshopper. An open circulatory system is a type of circulatory system where the circulating fluid, called hemolymph, is not confined to blood vessels but instead bathes the tissues directly. In this system, the hemolymph is pumped by a simple heart into the body cavity, where it comes into direct contact with the organs and tissues. The fluid then returns to the heart, and the cycle repeats. Now, let's go through the options: Amoeba: Amoebas are unicellular organisms and do not possess a circulatory system. Earthworm: Earthworms have a closed circulatory system. However, they have a modified version called a "closed circulatory system with open-ended vessels."

Why the other options are wrong
  • A. Amoeba: Amoebas are unicellular organisms and do not possess a circulatory system. They rely on simple diffusion to exchange gases and nutrients across their cell membranes.
  • B. Earthworm: Earthworms have a closed circulatory system. However, they have a modified version called a "closed circulatory system with open-ended vessels." In this system, the blood, or more accurately, the coelomic fluid, is contained within vessels, but those vessels are not completely closed. The coelomic fluid flows through the vessels and the body cavity, allowing direct contact with the tissues
  • D. Man: Humans, like other mammals, possess a closed circulatory system called the cardiovascular system. The blood is pumped by the heart into a network of blood vessels, including arteries, veins, and capillaries, which deliver oxygen, nutrients, and hormones to the tissues and remove waste products.

Q72. The glucose is reabsorbed by the

  • A. Proximal convoluted tubule of nephron
  • B. Distal convoluted tubule of nephron
  • C. Glomerulus
  • D. Bowman capsule

Explanation: The correct option is A. Glucose reabsorption primarily occurs in the proximal convoluted tubule (PCT) of the nephron in the kidney. The PCT is responsible for the reabsorption of various substances from the filtrate back into the bloodstream. Therefore, option A (Proximal convoluted tubule of nephron) is the correct answer as it is the primary site for glucose reabsorption in the kidney.

Why the other options are wrong
  • B. Option B is incorrect. The distal convoluted tubule is not primarily responsible for glucose reabsorption but is involved in electrolyte balance and pH regulation.
  • C. Option C is incorrect. The glomerulus is the initial filtration site where blood is filtered, but glucose reabsorption occurs in the tubular segments, not here.
  • D. Option D is incorrect. The Bowman's capsule is involved in the initial filtration of blood, but glucose reabsorption occurs in the tubular segments following filtration.

Q73. Where does esophagus open in the alimentary canal of earthworm?

  • A. Buccal chamber
  • B. intestine
  • C. rectum
  • D. intestinal caccum

Explanation: In earthworms, the esophagus connects the pharynx to the crop and then continues to the gizzard. The gizzard is a muscular organ that grinds the food into smaller particles before it enters the intestine, where digestion and absorption take place.The correct answer is Option B: intestine. The esophagus in an earthworm does not open directly into the intestine, but it connects the pharynx to the crop where food is temporarily stored. Options A, C, and D are incorrect because they do not accurately describe the location where the esophagus opens in the earthworm's alimentary canal.

Why the other options are wrong
  • A. The buccal chamber is the mouth cavity of the earthworm where ingestion of food occurs. The esophagus does not open directly into the buccal chamber. Instead, it is connected to the buccal chamber through the pharynx, which acts as a muscular tube that helps move food from the mouth into the esophagus.
  • C. The rectum is the terminal part of the alimentary canal, where the undigested food material is stored before being eliminated as waste. The esophagus does not open into the rectum. Instead, it connects the crop to the gizzard.
  • D. The intestinal cecum is a pouch-like structure found in some animals, such as herbivorous mammals, where the fermentation of food occurs. Earthworms do not have an intestinal cecum, so the esophagus does not open into it.

Q74. The process responsible for energy production in animals is:

  • A. photosynthesis
  • B. digestion
  • C. respiration
  • D. circulation

Explanation: Respiration: Respiration is the biochemical process by which cells break down organic molecules, such as glucose, and convert them into energy in the form of ATP (adenosine triphosphate). It occurs in the mitochondria of cells and involves the consumption of oxygen and the release of carbon dioxide. Respiration is the primary process responsible for energy production in animals. Photosynthesis, digestion, and circulation are all important processes in living organisms, but they do not directly produce energy in animals.

Why the other options are wrong
  • A. Photosynthesis is the process by which plants, algae, and some bacteria convert sunlight, water, and carbon dioxide into glucose and oxygen using chlorophyll. It is the primary process of energy production in plants, but not in animals.
  • B. Digestion is the process by which food is broken down and converted into nutrients that can be absorbed and utilized by the body. While digestion provides the necessary nutrients for energy production, it is not the direct process responsible for energy production itself.
  • D. Circulation refers to the movement of blood throughout the body, which transports nutrients, oxygen, and other substances to cells. While circulation is important for distributing oxygen and nutrients necessary for energy production, it is not the actual process of energy production itself.

Q75. The complex force of photosynthesis can be studied by the use of one of the following isotopes :

  • A. 6C14
  • B. 1H2
  • C. 2He4
  • D. 6O16

Explanation: Oxygen-16 is the ideal isotope for studying photosynthesis because it allows for precise measurements of oxygen uptake and flow during the process. Carbon-14, Hydrogen-2, and Helium-4 are not commonly used for this specific purpose, making them incorrect choices for this question.

Why the other options are wrong
  • A. Carbon-14 is commonly used in carbon dating, not specifically for studying photosynthesis.
  • B. Hydrogen isotope is versatile but not specifically used for studying photosynthesis.
  • C. Helium-4 isotope is mainly used in nuclear reactions, not in the study of photosynthesis.

Q76. Which of the following is not present in fish?

  • A. middle ear
  • B. internal ear
  • C. gills
  • D. fins

Explanation: Middle ear: Fish do not possess a middle ear like mammals. Instead, they have a unique structure called the swim bladder, which is used for buoyancy control and sound detection. The swim bladder is not directly involved in hearing like the middle ear in mammals.In summary, while fish possess internal ears, gills, and fins, they do not have a middle ear as found in mammals.

Why the other options are wrong
  • B. Internal ear: Fish have an internal ear, also known as the inner ear, which is responsible for balance, equilibrium, and detecting sound vibrations in the water. The inner ear contains sensory organs that help fish perceive their surroundings.
  • C. Gills: Fish have gills, specialized respiratory organs that extract oxygen from water. Gills enable fish to extract dissolved oxygen from the water and release carbon dioxide, facilitating their respiration.
  • D. Fins: Fish have fins, which are specialized appendages that aid in locomotion, stability, and maneuvering in water. Fins play a crucial role in fish movement, allowing them to swim, change direction, and maintain balance.

Q77. Lactose,maltose and sucrose are the important:

  • A. polysaccharides
  • B. disaccharides
  • C. monosaccharides
  • D. oligosaccharides

Explanation: Disaccharides are carbohydrates composed of two sugar units joined by a glycosidic bond. Lactose is made up of glucose and galactose, maltose is made up of two glucose molecules, and sucrose is made up of glucose and fructose.In summary, lactose, maltose, and sucrose are disaccharides, which are composed of two sugar units bonded together. Polysaccharides are more complex carbohydrates with multiple sugar units, monosaccharides are single sugar units, and oligosaccharides have a small number of sugar units, typically 3 to 10.

Why the other options are wrong
  • A. Polysaccharides are complex carbohydrates made up of multiple sugar units bonded together. Examples include starch and cellulose.
  • C. Monosaccharides are the simplest form of carbohydrates consisting of a single sugar unit. Examples include glucose, fructose, and galactose.
  • D. Oligosaccharides are carbohydrates composed of a small number of sugar units, typically 3 to 10. Examples include raffinose and stachyose.

Q78. The number of vertebrate in vertebrae column in man are:

  • A. 37
  • B. 35
  • C. 34
  • D. 33

Explanation: This option is correct. The vertebral column in humans consists of 33 vertebrae, including 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, 5 sacral vertebrae (fused into the sacrum), and 4 coccygeal vertebrae (fused into the coccyx)

Why the other options are wrong
  • A. This option is incorrect. The vertebral column in humans typically consists of 33 vertebrae.
  • B. This option is incorrect. The vertebral column in humans typically consists of 33 vertebrae.
  • C. This option is incorrect. The vertebral column in humans consists of 33 vertebrae, including 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, 5 sacral vertebrae (fused into the sacrum), and 4 coccygeal vertebrae (fused into the coccyx)

Q79. Grignard reagent is prepared by reacting:

  • A. Alkyl Halide and Mg
  • B. Alkane and Mg
  • C. Alcohol and Mg
  • D. None of them

Explanation: Alkyl Halide and Mg extremely good nucleophiles, reacting with electrophiles such as carbonyl compounds and epoxides

Why the other options are wrong
  • B. As they are derivative of alkyl halides so we have to add halogen to alkane to make it alkyl halide as compared to alkyl halide
  • C. Mg does not react with alcohol under normal conditions

Q80. Which of the following carboxylic acid is the strongest?

  • A. Dichloroacetic acid
  • B. Chloroacetic acid
  • C. Formic acid
  • D. Acetic acid

Explanation: Greater -I effect, due to the presence of two chloro groups increase the acid strength of dichloroacetic acid

Why the other options are wrong
  • B. Less -I effect, as contain only one chloro group as compared to dichloroacetic acid
  • C. Formic acid do not completely dissociate into it's constituent ions when dissolved in water but it is stronger than acetic acid
  • D. acetic acid is not a strong enough proton donor to be entirely converted to hydronium ions in aqueous solution.

Q81. Which compound has the highest boiling point?

  • A. C2H6
  • B. C2H2Cl
  • C. CH3OCH3
  • D. C2H5OH

Explanation: Among the given compounds, C2H5OH (ethanol) has the highest boiling point. The boiling points of the compounds increase as the intermolecular forces between their molecules increase. C2H5OH (ethanol) has a polar covalent bond between the carbon and oxygen atoms, which gives rise to strong hydrogen bonding interactions between its molecules. Hydrogen bonding is a particularly strong type of dipole-dipole interaction that arises when a hydrogen atom bonded to an electronegative atom, in this case oxygen, interacts with the lone pair of electrons on another electronegative atom in a different molecule, also in this case oxygen. As a result, ethanol has a much higher boiling point than the other compounds, at 78.5 °C.

Why the other options are wrong
  • A. C2H6 (ethane) is a simple hydrocarbon with no polarity, so it has only weak London dispersion forces between its molecules. As a result, its boiling point is relatively low, at -88.6 °C.
  • B. C2H2Cl (vinyl chloride) has a polar covalent bond between the carbon and chlorine atoms, which gives rise to dipole-dipole interactions between its molecules. However, these interactions are weaker than the hydrogen bonding interactions found in ethanol, and so its boiling point is higher than ethane, but lower than ethanol, at -13.4 °C.
  • C. CH3OCH3 (dimethyl ether) has a polar covalent bond between the carbon and oxygen atoms, which also gives rise to dipole-dipole interactions between its molecules. However, dimethyl ether cannot form hydrogen bonds with other ether molecules, since it does not have any hydrogen atoms bonded to oxygen. Thus, its boiling point is lower than ethanol, at -23.6 °C.

Q82. Carbon atom in carbonyl is:

  • A. SP hybridized
  • B. SP2 hybridized
  • C. SP3 hybridized
  • D. None of the above

Explanation: In a carbonyl, the carbon atom is double-bonded to an oxygen atom and single-bonded to another atom. The oxygen atom is more electronegative than the carbon atom, so it pulls the electrons towards itself and creates a partial positive charge on the carbon atom. To accommodate this charge separation, the carbon atom must be hybridized. Hybridization is the mixing of atomic orbitals to form hybrid orbitals that have different shapes and energies from the atomic orbitals. The carbon atom in a carbonyl forms three sigma bonds in the molecule, and one pi bond with the oxygen atom. In SP2 hybridization, the carbon atom uses one S orbital and two P orbitals to form three hybrid orbitals that are arranged in a trigonal planar geometry. The remaining P orbital of carbon overlaps with the P orbital of oxygen to form the pi bond. Therefore, the carbon atom in a carbonyl is SP2 hybridized.

Why the other options are wrong
  • A. In a carbonyl, the carbon atom is double-bonded to an oxygen atom and single-bonded to another atom. The oxygen atom is more electronegative than the carbon atom, so it pulls the electrons towards itself and creates a partial positive charge on the carbon atom. To accommodate this charge separation, the carbon atom must be hybridized.

Q83. The unit of 1st order rate constant are :

  • A. Sec
  • B. Sec-¹
  • C. Mol dm-³sec-¹
  • D. None of the above

Explanation: Because the units of the reaction rate are always moles per liter per second, the units of a first-order rate constant are reciprocal seconds (s−1).

Why the other options are wrong
  • A. is incorrect because it only represents seconds as a unit and does not include the negative exponent required for rate constants.
  • C. is incorrect because it represents the units for the rate of reaction, which is different from the rate constant.

Q84. The paramagnetic nature of the substance depend on;

  • A. The number of electrons in the outermost shell
  • B. The number of electrons that are easily ejected
  • C. The number of unpaired electrons
  • D. The number of lone pair electrons

Explanation: A paramagnetic substance is one that is weakly attracted by a magnetic field due to the presence of unpaired electrons in its atoms or molecules. The unpaired electrons have a magnetic moment, which causes the substance to be attracted to an external magnetic field. Therefore, the correct answer is that the paramagnetic nature of a substance depends on the number of unpaired electrons. When all the electrons in an atom or molecule are paired, the substance is diamagnetic and is not attracted to a magnetic field.

Why the other options are wrong
  • A. The number of electrons in the outermost shell (option a) is not directly related to the paramagnetic nature of a substance. However, the number of electrons in the outermost shell can affect the electron configuration of the atom, which in turn can determine whether or not there are unpaired electrons.
  • B. The number of electrons that are easily ejected (option b) is also not directly related to the paramagnetic nature of a substance. This property refers to the ionization energy, which is the energy required to remove an electron from an atom or molecule.
  • D. The number of lone pair electrons (option d) is also not directly related to the paramagnetic nature of a substance. Lone pair electrons are paired electrons that are not involved in chemical bonding, and they do not contribute to the magnetic properties of the substance.

Q85. When does a reaction attain equilibrium :

  • A. When forward and backward reaction taking place at the same rate
  • B. Reaction takes place
  • C. The forward and backward
  • D. There are two reactions with one faster than the other

Explanation: At equilibrium, the rates of the forward and backward reactions are equal, and there is no net change in the concentrations of the reactants and products. This means that the system has reached a state of balance, where the concentrations of the reactants and products remain constant over time.

Why the other options are wrong
  • B. "Reaction takes place" is incorrect because this statement does not indicate whether the reaction has reached equilibrium or not. A reaction can take place without reaching equilibrium if the products are continuously removed or the reactants are continuously added.
  • C. "The forward and backward" is incomplete and unclear. It is not clear what is happening to the forward and backward reactions.
  • D. "There are two reactions with one faster than the other" is incorrect because this statement does not necessarily lead to equilibrium. Even if one reaction is faster than the other, the system may not reach equilibrium if the products are continuously removed or the reactants are continuously added.

Q86. The following compunds, which has the shortest carbon _ Halogen bond:

  • A. CH3F
  • B. CH3I
  • C. CH3Cl
  • D. CH3Br

Explanation: The carbon-halogen bond length is determined by the size of the halogen atom. The larger the halogen atom, the longer the bond length. Therefore, in the given compounds, CH3F has the shortest carbon-halogen bond because fluorine is the smallest halogen.

Why the other options are wrong
  • B. In contrast, CH3I has the longest carbon-halogen bond because iodine is the largest halogen.
  • C. The bond lengths of CH3Cl and CH3Br lie between those of CH3F and CH3I.
  • D. The bond lengths of CH3Cl and CH3Br lie between those of CH3F and CH3I.

Q87. Which of the following species deactivate the benzene ring when attached to benzene ring?

  • A. C2H5
  • B. SO3H
  • C. NH2
  • D. CH3

Explanation: order of activating group (NH2, NHR, NHCOCH3, OCH3,CH3,C2H5(and deactivating group (NO2, CN, CHO, COR, COOH, COOR, SO3H)to increase and decrease reactivity of electrophilic substitution. Out of the given options, the following species deactivate the benzene ring when attached to the benzene ring: SO3H (sulfonic acid group) This is called deactivating groups because they decrease the electron density of the benzene ring through resonance and/or inductive effects. This makes the benzene ring less reactive towards electrophilic substitution reactions.

Why the other options are wrong
  • A. On the other hand, C2H5 (ethyl group) and CH3 (methyl group) are electron-donating groups and activate the benzene ring towards electrophilic substitution reactions.
  • D. On the other hand, C2H5 (ethyl group) and CH3 (methyl group) are electron-donating groups and activate the benzene ring towards electrophilic substitution reactions.

Q88. The elements arsenic and Antimony are considered as:

  • A. Metals
  • B. Non metal
  • C. Metalloid
  • D. None of the above

Explanation: Arsenic and Antimony are classified as metalloids. Metalloids are elements that have properties of both metals and nonmetals. Arsenic and antimony are situated in the p-block of the periodic table and have properties intermediate between those of a metal and a nonmetal. They have metallic luster and are semiconductors, but they are brittle and can be easily broken. They can also act as either an oxidizing agent or reducing agent in chemical reactions, depending on the conditions.

Why the other options are wrong
  • A. They do not have the properties of metals.
  • B. They also do not have the properties of non metals.

Q89. Benzene is the prime member of:

  • A. A cyclic compounds
  • B. Ali cyclic compounds
  • C. Hetro cyclic compounds
  • D. Aromatic compounds

Explanation: Aromatic compounds are a class of cyclic organic compounds that contain one or more rings with a special stability due to the delocalization of electrons in the ring. Benzene is a cyclic compound with six carbon atoms and six hydrogen atoms. It is the simplest and most common aromatic compound. The electrons in the benzene ring are delocalized, which gives the compound its unique stability and reactivity.

Why the other options are wrong
  • A. Cyclic compounds are organic compounds that contain one or more rings of carbon atoms in their structure. Benzene is a cyclic compound with a six-membered carbon ring.
  • B. Alicyclic compounds are cyclic compounds that do not contain any aromatic rings. They can be saturated or unsaturated, and their properties are determined by the type of ring and its substituents.
  • C. Heterocyclic compounds are cyclic organic compounds that contain at least one heteroatom (other than carbon) in the ring. Examples include pyridine, furan, and pyrrole.

Q90. The sodium ion is ISO electronic with:

  • A. N
  • B. P-³
  • C. K+
  • D. F-

Explanation: O2-, F–, Na+ and Mg2+ are known as isoelectronic species as they all have the same no. of electrons(10).

Why the other options are wrong
  • A. Don't have same no of electrons as of Na.
  • B. Don't have same no of electrons as of Na.
  • C. Don't have same no of electrons as that of Na.

Q91. In which of the following solvent are alkenes the most soluble?

  • A. Water
  • B. Ethyl alcohol
  • C. Ammonia
  • D. Carbon tetrachloride

Explanation: CCl4 is non polar so as ethene is… They dissolve in each other perfectly because of same nature

Why the other options are wrong
  • A. Water is polar and ethene is non polar. Like dissolves like
  • B. Ethyl alcohol is polar.
  • C. Ammonia is also polar

Q92. The change in enthalpy is a measure of the heat reaction at:

  • A. Constant Volume
  • B. Constant Pressure and volume
  • C. Variable pressure
  • D. Constant pressure

Explanation: Enthalpy is a thermodynamic state function that represents the internal energy of a system plus the product of pressure and volume. It is expressed as ΔH, which is the change in enthalpy during a chemical reaction. Constant pressure: At constant pressure, the change in enthalpy is equal to the heat absorbed or released by the system, as well as the work done by or on the system against the constant pressure.

Why the other options are wrong
  • A. Constant volume: At constant volume, no work is done by or on the system, hence no pressure-volume work is done. Therefore, the change in enthalpy is equal to the internal energy change of the system.
  • B. Constant pressure and volume: This condition is not possible as the two conditions contradict each other. If the volume is constant, the pressure cannot be constant, and vice versa.
  • C. Variable pressure: In this case, the change in enthalpy is equal to the heat absorbed or released by the system, as well as the work done by or on the system against the varying pressure.

Q93. Reaction of alcohol with Sodium produces:

  • A. Alkoxides
  • B. Ethane
  • C. Alkane
  • D. Alloyed

Explanation: Alcohols react with sodium to form a salt (sodium alkoxide) and bubbles of hydrogen gas will be seen. This is similar to the reaction of water with sodium, except it is far less violent. The salt formed from the reaction with sodium and ethanol is called sodium ethoxide. When an alkali metal, such as sodium, is added to an alcohol, the alcohol will undergo a deprotonation reaction. The alkoxide ion, R-O-, is formed as a result of the transfer of a proton from the alcohol to the metal. For example, when sodium reacts with ethanol (CH3CH2OH), it forms sodium ethoxide (CH3CH2O-Na+).

Why the other options are wrong

    Q94. Thermite process is:

    • A. Exothermic
    • B. Endothermic
    • C. Reversible
    • D. None of above

    Explanation: Exothermic: An exothermic reaction is a chemical reaction that releases energy in the form of heat. In the case of the thermite process, it is indeed exothermic. The reaction involves the highly exothermic oxidation-reduction reaction between a metal oxide and a reducing agent, usually aluminum. The reaction produces a significant amount of heat, resulting in a rapid increase in temperature and the generation of intense heat and light. The exothermic nature of the thermite process makes it useful for various applications, such as welding and incendiary devices.

    Why the other options are wrong
    • B. Endothermic: An endothermic reaction is a chemical reaction that absorbs energy from its surroundings. The thermite process is not endothermic since it releases heat rather than absorbing it. It is important to note that endothermic reactions are characterized by a decrease in temperature or a cooling effect.
    • C. Reversible: A reversible reaction is a chemical reaction that can proceed in both forward and reverse directions under suitable conditions. The thermite process is not reversible. Once the reaction is initiated by heating or igniting the thermite mixture, it proceeds rapidly and irreversibly to completion. The reactants (metal oxide and reducing agent) are transformed into the products (metal and oxygen) without the ability to revert back to the original reactants.

    Q95. In the laboratory standard solution is prepared in?

    • A. Conical flasks
    • B. Beakers
    • C. Volumetric flask
    • D. Measuring cylinder

    Explanation: Volumetric flasks, on the other hand, are specifically designed for accurate measurement of a specific volume and are the preferred choice for preparing standard solutions.

    Why the other options are wrong
    • A. Conical flasks and beakers are commonly used in laboratories, they are not typically used for preparing standard solutions.
    • B. Beakers are commonly used in laboratories for general mixing, heating, and storing liquids. Similar to conical flasks, beakers are not as accurate or precise as volumetric flasks for preparing standard solutions.
    • D. Measuring cylinders, although useful for approximate measurements, are not as precise as volumetric flasks and are not typically used for preparing standard solutions.

    Q96. Nitrogen has three unpaired electrons according to:

    • A. Hund's rule
    • B. Aulban rule
    • C. Paoli's exclusion lrinciple
    • D. Thumb rule

    Explanation: Hund's Rule: Hund's rule is a principle in quantum mechanics that states that for a given electron shell, orbitals of equal energy are filled with one electron each before any orbital receives a second electron. This rule applies to atoms or ions with multiple orbitals available at the same energy level. According to Hund's rule, when nitrogen is in its ground state, its three 2p orbitals are singly occupied by electrons with parallel spins, resulting in three unpaired electrons. In summary, the statement that nitrogen has three unpaired electrons aligns with Hund's rule, which describes the distribution of electrons in orbitals of equal energy.

    Why the other options are wrong
    • B. Aufbau Principle: The Aufbau principle states that electrons fill atomic orbitals in order of increasing energy levels. Electrons first occupy the lowest energy orbitals before moving to higher energy levels. While the Aufbau principle is relevant to understanding the electronic configuration of nitrogen, it does not directly determine the number of unpaired electrons.
    • C. Pauli's Exclusion Principle: Pauli's exclusion principle states that no two electrons in an atom can have the same set of four quantum numbers. In other words, electrons in the same atom must have different spin quantum numbers. Pauli's exclusion principle is fundamental to understanding the electronic structure of atoms, but it does not specifically address the number of unpaired electrons in nitrogen.
    • D. Thumb Rule: There is no widely recognized "Thumb rule" in the context of electron configuration or the number of unpaired electrons. It is possible that this option refers to the general understanding that, based on the electronic configuration and Hund's rule, nitrogen has three unpaired electrons, which can be represented by using one's thumb to count the unpaired electrons.

    Q97. The inert form of carbon is:

    • A. Diamond
    • B. Graphite
    • C. Coal
    • D. Charcoal

    Explanation: Diamond: Diamond is the inert form of carbon. It is a crystalline structure where each carbon atom is bonded to four neighboring carbon atoms in a tetrahedral arrangement, making it extremely hard and resistant to chemical reactions.

    Why the other options are wrong
    • B. Graphite: Graphite is not an inert form of carbon. It consists of layers of carbon atoms arranged in a hexagonal lattice, and it can undergo reactions with certain chemicals and high temperatures.
    • C. Coal: Coal is not an inert form of carbon. It is a solid fossil fuel formed from the remains of plants. When burned, coal undergoes combustion, releasing carbon dioxide and other gases.
    • D. Charcoal: Charcoal is not an inert form of carbon. It is produced by heating wood or other organic materials in the absence of oxygen. While it is less reactive than coal or graphite, charcoal can still undergo reactions when exposed to certain chemicals or high temperatures.

    Q98. For the separation of gases from a mixture we use:

    • A. Simple diffusion
    • B. Fractional distillation
    • C. Chromatography
    • D. Graham's law of diffusion

    Explanation: Fractional distillation is the special technique which is used for separation of mixture of two gases

    Why the other options are wrong
    • A. Diffusion process in which the substance moves through a semipermeable membrane or in a solution without any help from transport proteins
    • C. Chromatography enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis.
    • D. Graham's law of diffusion helps in the separation of isotopes of certain elements.

    Q99. Which one of the following forms the most acidic oxide:

    • A. Al
    • B. Si
    • C. Fe
    • D. P

    Explanation: Phosphorus being more electronegative than Si forms more acidic oxides.

    Why the other options are wrong
    • A. Al forms neutral oxides.
    • B. Si forms weak acidic oxide due to small electronegativity and react with strong bases
    • C. Since, Iron is a metal, its oxides are basic in nature

    Q100. Which statement is correct:

    • A. Standard Hydrogen Electrode SHE always acts as anode
    • B. SHE may act as cathode or anode depending upon the reduction potential of the counterpart
    • C. SHE always acts as cathode in voltaic cell
    • D. None of the above

    Explanation: SHE may act as cathode or anode depending upon the reduction potential of the counterpart: This statement is correct. The role of the SHE in a voltaic or electrolytic cell is determined by the reduction potential (also known as standard electrode potential) of the other electrode or species involved in the cell. The electrode with a higher reduction potential will act as the cathode, while the one with a lower reduction potential will act as the anode. The SHE can serve as either the cathode or the anode, depending on the specific conditions and the reduction potential of the counterpart. The correct statement is: SHE may act as cathode or anode depending upon the reduction potential of the counterpart.

    Why the other options are wrong
    • A. Standard Hydrogen Electrode (SHE) always acts as anode: This statement is incorrect. The SHE is often used as a reference electrode in electrochemical cells, and its role as an anode or cathode depends on the specific reaction occurring in the cell. The SHE itself doesn't always act as an anode.
    • C. SHE always acts as cathode in a voltaic cell: This statement is incorrect. In a voltaic (galvanic) cell, the SHE can act as either the cathode or the anode, depending on the reduction potential of the other electrode involved in the cell. The cathode is where reduction occurs, and the anode is where oxidation occurs. The specific reaction and the reduction potential determine the role of the SHE in the voltaic cell.

    Q101. The stronger the reduction potential the more difficult it is to?

    • A. Oxidize the compound
    • B. Reduce the compound
    • C. Electrolyze the compound
    • D. None of the above

    Explanation: Oxidize the compound: A stronger reduction potential indicates that the compound is more likely to undergo reduction rather than oxidation. Therefore, it would be more difficult to oxidize the compound.

    Why the other options are wrong
    • B. Reduce the compound: A stronger reduction potential means that the compound has a higher tendency to gain electrons and undergo reduction. Hence, it would be easier to reduce the compound.
    • C. Electrolyze the compound: Electrolysis involves the use of an electric current to drive a non-spontaneous chemical reaction. If the compound has a strong reduction potential, it means it is more stable in its reduced state, making it more difficult to electrolyze.

    Q102. What is the ionic strength of 0.01M barium chloride solution :

    • A. 0.03
    • B. 0.02
    • C. 0.04
    • D. 0.01

    Explanation: 0.01: This option is correct. The ionic strength is equal to 0.01. In this case, the concentration of both the barium ions (Ba2+) and chloride ions (Cl-) is 0.01 M. Since there is only one ion of each type, the sum of their concentrations gives the total ionic strength of the solution, which is 0.01 M. The ionic strength of a solution is a measure of the total concentration of ions in the solution. In this case, we have a 0.01 M barium chloride solution. To calculate the ionic strength, we need to consider the contribution of both the barium ions (Ba2+) and chloride ions (Cl-) to the total ionic concentration.

    Why the other options are wrong
    • A. This option is not correct. The ionic strength is not equal to 0.03. It would be too high for a 0.01 M solution.
    • B. 0.02: This option is not correct. The ionic strength is not equal to 0.02. It would be too high for a 0.01 M solution.
    • C. 0.04: This option is not correct. The ionic strength is not equal to 0.04. It would be too high for a 0.01 M solution.

    Q103. Stoichiometric calculation based on chemical equation provides us intimation about :

    • A. Theoretical yield
    • B. Practical yield
    • C. Percentage yield
    • D. All of above

    Explanation: Stoichiometry uses the balanced chemical equation to calculate how much product can theoretically form from given amounts of reactants.Practical (actual) yield and percentage yield are experimental results, which are determined by performing the reaction in the lab. They cannot be predicted from stoichiometry alone.So, stoichiometry gives theoretical yield, not practical yield or percentage yield.

    Why the other options are wrong
    • B. Practical yield: The actual amount of product obtained from a reaction in the laboratory.
    • C. Percentage yield: The ratio of the practical yield to the theoretical yield, expressed as a percentage. It indicates the efficiency of a reaction.
    • D. Stoichiometry uses the balanced chemical equation to calculate how much product can theoretically form from given amounts of reactants.Practical (actual) yield and percentage yield are experimental results, which are determined by performing the reaction in the lab. They cannot be predicted from stoichiometry alone.So, stoichiometry gives theoretical yield, not practical yield or percentage yield.

    Q104. Which one is the separating technique:

    • A. Deliquescence
    • B. Fluorescence
    • C. Phosphorescence
    • D. Solvent extraction

    Explanation: Solvent extraction is used for separation of mixtures

    Why the other options are wrong
    • A. deliquescence, the process by which a substance absorbs moisture from the atmosphere until it dissolves in the absorbed water and forms a solution.
    • B. Fluorescence is where a material absorbs a photon, and almost immediately emits a lower energy photon.
    • C. Phosphorescence is the time in between absorbance and the emission of photons.

    Q105. Which one is used as stationary phase in paper chromatography?

    • A. Alcohol
    • B. Adeline
    • C. Piece of paper
    • D. Water absorbed on paper

    Explanation: Water absorbed on paper: This option is correct. In paper chromatography, the stationary phase is usually achieved by impregnating the paper with water or a suitable aqueous solution. The water absorbed on the paper fibers acts as the stationary phase, while the mobile phase (solvent) carries the components of the sample along the paper.

    Why the other options are wrong
    • A. Alcohol: Alcohol is typically used as a mobile phase in paper chromatography, where it acts as a solvent to carry the components of the sample along the paper. It is not used as the stationary phase.
    • B. Adeline: There is no specific reference to "Adeline" in the context of paper chromatography. It is likely a typo or an incorrect term.
    • C. Piece of paper: This option is incorrect. While paper itself is used as a substrate or support in paper chromatography, it is not considered the stationary phase. The stationary phase refers to a specific material or substance that is applied or impregnated onto the paper.

    Q106. There are three quantum numbers n.1 and m ( all integers) characterizing each solution of the schrodinger equation. If n=3, what is the range of possible values for m?

    • A. ±3
    • B. ±1/2
    • C. ±2
    • D. Any positive number from 0 to -1

    Explanation: n = 3, so possible l = 0, 1, 2For each l, m = -l to +lSo:l = 0 → m = 0l = 1 → m = -1, 0, +1l = 2 → m = -2, -1, 0, +1, +2✅ Range of m: -2 to +2

    Why the other options are wrong
    • A. This option is incorrect. The range of possible values for m with n=3 is from -2 to +2, not ±3.
    • B. ±1/2: This option is incorrect. The quantum number m must be an integer value, so ±1/2 is not a valid choice for m.
    • D. Any positive number from 0 to -1: This option is incorrect. The quantum number m must be an integer and cannot be a positive number or a negative number between 0 and -1.

    Q107. In hydronium ion, what is the nature of bond between oxygen of water and hydrogen ion in an acidic solution?

    • A. Covalent
    • B. Electrovalent
    • C. Hydrogen bond
    • D. Coordinate covalent bond

    Explanation: Coordinate covalent bond: A coordinate covalent bond is formed when one atom donates a pair of electrons to be shared with another atom. In the hydronium ion, the oxygen atom of water donates a pair of electrons to form a bond with the hydrogen ion, resulting in a coordinate covalent bond.

    Why the other options are wrong
    • A. A covalent bond involves the sharing of electrons between atoms, but in the case of the hydronium ion, the bond is not formed by electron sharing.
    • B. Electrovalent: An electrovalent bond (ionic bond) is the transfer of electrons between atoms, but in the case of the hydronium ion, the bond is not formed by electron transfer.
    • C. Hydrogen bond: A hydrogen bond is an attractive force between a hydrogen atom and an electronegative atom (such as oxygen or nitrogen) of another molecule. However, in the case of the hydronium ion, the bond between oxygen and the hydrogen ion is not a hydrogen bond.

    Q108. Real gases deviate more from ideal behavior at :

    • A. High temperature only
    • B. High pressure only
    • C. High pressure and low temperature
    • D. Low pressure and high temperature

    Explanation: High pressure and low temperature: Both high pressure and low temperature amplify intermolecular forces, leading to greater deviations from ideal behavior. The reduced kinetic energy and increased proximity of gas particles result in stronger attractive forces, impacting gas behavior.

    Why the other options are wrong
    • A. High temperature only: At high temperatures, the kinetic energy of gas particles increases, causing them to move faster and exhibit weaker intermolecular attractions. This leads to a decrease in deviations from ideal behavior.
    • B. High pressure only: At high pressures, the volume occupied by gas particles becomes significant compared to the total volume, and intermolecular forces start to influence gas behavior more, causing deviations from ideal behavior.
    • D. Low pressure and high temperature: At low pressures and high temperatures, gas particles are far apart, and the effect of intermolecular forces diminishes. Deviations from ideal behavior are minimal since the gas behaves more like an ideal gas due to reduced intermolecular interactions.

    Q109. Particles involves in an ordinary chemical reaction are:

    • A. Protons
    • B. Neutrons
    • C. Electrons
    • D. All of above

    Explanation: Electrons (especially valence electrons) are only subatomic particles which are involved in ordinary chemical changes

    Why the other options are wrong
    • A. Protons give mass to atom but do not participate in chemical reactions.
    • B. Like protons, neutrons also give mass (weight) to the atom but do not participate in chemical reactions.

    Q110. The phenomenon of cooling on sudden expansion of gases is called:

    • A. Bronstect effect
    • B. Joule Thomson effect
    • C. Graham's effect
    • D. Dalton's effect

    Explanation: Therefore, the correct term is the "Joule-Thomson effect," which describes the cooling observed when a gas expands rapidly without any external work being done on it. The phenomenon of cooling on sudden expansion of gases is called the "Joule-Thomson effect."

    Why the other options are wrong
    • A. Bronstect effect: This term is not related to the given phenomenon and is incorrect.
    • C. This refers to the diffusion of gases through a porous medium, not cooling on expansion.
    • D. Dalton's effect: This term does not exist in relation to the given phenomenon and is incorrect.

    Q111. Fizzy drinks contain dissolved CO2. The CO2 reacts with H2O to form weak acid which is called:

    • A. Acetic acid
    • B. Carbonic acid
    • C. Lactic acid
    • D. Formic acid

    Explanation: The weak acid formed when CO2 reacts with water in fizzy drinks is called "Carbonic acid." Therefore, the correct option is "Carbonic acid" as it is the specific weak acid formed when CO2 dissolves in water.

    Why the other options are wrong
    • A. Acetic acid: A different acid commonly found in vinegar, not formed by the reaction of CO2 and water.
    • C. Lactic acid: Produced in certain metabolic processes and found in sour milk products, not related to CO2 in fizzy drinks.
    • D. Formic acid: Found in ants and other insects, not associated with the reaction of CO2 and water.

    Q112. Cleaning action of soap is due to:

    • A. Decrease in surface tension of water
    • B. Viscosity of water
    • C. High boiling point of water
    • D. Polarity of water

    Explanation: Polarity of water: Soap molecules have polar and nonpolar regions, allowing them to interact with both water and oily substances, facilitating the removal of dirt and oils. Therefore, the correct option for the cleaning action of soap is "Polarity of water."

    Why the other options are wrong
    • A. Decrease in surface tension of water: Soap molecules disrupt the cohesive forces between water molecules, reducing surface tension and allowing easier wetting and removal of dirt and oils.
    • B. Viscosity of water: The viscosity of water is not directly related to the cleaning action of soap.High boiling point of water: The high boiling point of water is not directly related to the cleaning action of soap.
    • C. The cleaning action of soap is not due to high boiling point of water. It has no link with it.

    Q113. Polymerization is a process of producing:

    • A. High molecular weight compounds from monomers
    • B. Low molecular weight compounds from monomers
    • C. Intermediate molecular weight compound from monomers
    • D. High molecular weight compounds from polymers

    Explanation: High molecular weight compounds from monomers: This is the correct option. Polymerization involves the bonding of monomers to form long chains or networks, resulting in high molecular weight polymers. Therefore, the correct option is "High molecular weight compounds from monomers" as polymerization is the process of joining monomers to form larger, high molecular weight polymer molecules.

    Why the other options are wrong
    • B. Low molecular weight compounds from monomers: Polymerization does not result in the production of low molecular weight compounds.
    • C. Intermediate molecular weight compounds from monomers: Polymerization typically leads to the formation of high molecular weight compounds, not intermediate molecular weight compounds.
    • D. High molecular weight compounds from polymers: Polymerization does not involve the production of high molecular weight compounds from pre-existing polymers.

    Q114. Both H ion and helium atom have the same number of:

    • A. Proton
    • B. Electron
    • C. Neutrons
    • D. None of above

    Explanation: Therefore, the correct option is "None of the above" as H+ ion and helium atom have different numbers of protons, electrons, and neutrons.

    Why the other options are wrong
    • A. Proton: Helium atom has two protons, while the hydrogen ion (H+) has only one proton.
    • B. Electron: Helium atom has two electrons, while the hydrogen ion (H+) has lost its electron and has none.
    • C. Neutrons: Helium atom has two neutrons, while the hydrogen ion (H+) has no neutrons.

    Q115. CO2 is isostructural with:

    • A. HgCl2
    • B. SnCl2
    • C. C2H2
    • D. NO2

    Explanation: NO2: This option is correct. NO2 (nitrogen dioxide) has a linear molecular geometry and is isostructural with CO2. Both molecules have a central atom bonded to two surrounding atoms with no lone pairs, resulting in a linear shape. Therefore, the correct option is "NO2" as it is isostructural with CO2, meaning they have the same molecular geometry of linear shape.

    Why the other options are wrong
    • A. HgCl2: This option is incorrect. HgCl2 (mercury(II) chloride) has a linear molecular geometry, but it is not isostructural with CO2.
    • B. SnCl2: This option is incorrect. SnCl2 (tin(II) chloride) has a bent molecular geometry, so it is not isostructural with CO2.
    • C. C2H2: This option is incorrect. C2H2 (acetylene) has a linear molecular geometry, but it is not isostructural with CO2.

    Q116. How many subshells are present in n=3 shell:

    • A. 4
    • B. 3
    • C. 5
    • D. 9

    Explanation: This option is correct. The n=3 shell has three subshells corresponding to l=0, l=1, and l=2. Therefore, the correct option is "3" as there are three subshells (s, p, and d) in the n=3 shell according to the allowed values of l.

    Why the other options are wrong
    • A. This option is incorrect. The maximum value of l in the n=3 shell is 2, so there are three subshells (l=0, l=1, and l=2).
    • C. This option is incorrect. The n=3 shell does not have five subshells.
    • D. This option is incorrect. The n=3 shell does not have nine subshells.

    Q117. All the compounds are inorganic Except:

    • A. CaCO3
    • B. CAC2
    • C. KCN
    • D. (NH2)CO

    Explanation: (NH2)CO (urea): This compound is organic as it contains carbon-hydrogen (C-H) bonds and is commonly found in biological systems. Therefore, the correct answer is "(NH2)CO" as it is the only compound among the given options that is organic.

    Why the other options are wrong
    • A. CaCO3 (calcium carbonate): This compound is inorganic as it does not contain carbon-hydrogen (C-H) bonds and is commonly found in minerals and rocks.
    • B. CAC2 (calcium carbide): This compound is inorganic and is used in the production of acetylene gas.
    • C. KCN (potassium cyanide): This compound is inorganic and is a highly toxic substance used in various industrial processes.

    Q118. Molecules of oxygen is diatomic and behaves as:

    • A. Diamagnetic
    • B. Paramagnetic
    • C. Ferromagnetic
    • D. Anti Ferromagnetic

    Explanation: Paramagnetic: Oxygen molecules (O2) are paramagnetic. Paramagnetic substances have unpaired electrons, which generate a net magnetic moment. When placed in an external magnetic field, paramagnetic substances are weakly attracted to the field. Therefore, the correct option for oxygen molecules (O2) is "Paramagnetic" as they have unpaired electrons, generating a net magnetic moment and exhibiting weak attraction when placed in an external magnetic field.

    Why the other options are wrong
    • A. Diamagnetic: Oxygen molecules (O2) are diamagnetic. Diamagnetic substances have all their electrons paired, resulting in no net magnetic moment. When placed in an external magnetic field, diamagnetic substances are weakly repelled by the field.
    • C. Ferromagnetic: Oxygen molecules (O2) are not ferromagnetic. Ferromagnetic materials exhibit strong magnetic properties and can retain their magnetization even after the external magnetic field is removed. Oxygen is not a ferromagnetic material.
    • D. Antiferromagnetic: Oxygen molecules (O2) are not antiferromagnetic. Antiferromagnetic materials have neighboring magnetic moments that align in opposite directions, resulting in a zero net magnetic moment. Oxygen does not exhibit antiferromagnetic behavior.

    Q119. Which is strongest acid?

    • A. HClO
    • B. HClO2
    • C. HClO3
    • D. HClO4

    Explanation: HClO4 (perchloric acid): This acid is the strongest among the options. It is a highly corrosive and reactive acid. Perchloric acid is a strong oxidizing agent and is used in laboratories for various purposes. Therefore, the correct answer is "HClO4" (perchloric acid) as it is the strongest acid among the given options.

    Why the other options are wrong
    • A. HClO (hypochlorous acid): This acid is a weak acid compared to the other options. It is formed when chlorine reacts with water and is a weak oxidizing agent commonly used as a disinfectant.
    • B. HClO2 (chlorous acid): This acid is also a weak acid. It is an intermediate in the synthesis of other chlorine compounds and is not as strong as the next two options.
    • C. HClO3 (chloric acid): This acid is stronger than HClO and HClO2. It is a strong acid and is used in the production of various chemicals and explosives.

    Q120. TiCl4 is used as catalyst for the manufacture of:

    • A. Sulphuric acid
    • B. Plastics
    • C. Ethanol
    • D. Tetraethyl lead

    Explanation: TiCI4 is used as a catalyst in the Ziegler-Natta process, which helps convert ethylene into polyethylene. The other options are wrong because they use different catalysts (like V2O5 for H2SO4)or different production methods.

    Why the other options are wrong
    • A. Sulphuric acid is primarily used as a strong acid catalyst in esterification and dehydration reactions, not in the context of TiCl4.
    • C. Ethanol production typically involves fermentation or hydration of ethylene, which do not require TiCl4 as a catalyst.
    • D. Tetraethyl lead was used as an anti-knock agent in gasoline, but its production does not involve TiCl4 as a catalyst.

    Q121. The shape or appearance in which crystal grows is called:

    • A. Crystal geometry
    • B. Crystal lattice
    • C. Crystal habit
    • D. None of the above

    Explanation: The general shape of a crystal and the proportions of its bounding sides–such as elongate, tabular, bladed, or other–is known as its habit, from the Latin habitus

    Why the other options are wrong
    • A. Crystal structure is described in terms of the geometry of arrangement of particles in the unit cells.
    • B. Crystal lattice is the symmetrical three-dimensional arrangement of atoms inside a crystal.

    Q122. Species in which the central atom uses sp hybride orbital in its bonding is:

    • A. PH3
    • B. NH3
    • C. SbH3
    • D. C2H2

    Explanation: Each carbon in C₂H₂ is sp hybridized, it forms two sigma bonds (one with H, one with C) and uses two unhybridized p orbitals for the π bonds in the triple bond.

    Why the other options are wrong
    • A. Not sp hybridized.
    • B. Not sp hybridized.
    • C. Not sp hybridized.

    Q123. SO2 is responsible fir the formation of:

    • A. Acid rain
    • B. Green house effect
    • C. Global warming
    • D. Ozone depletion

    Explanation: Acid rain: SO2 is a major contributor to the formation of acid rain. When released into the atmosphere, it reacts with water and other substances to form sulfuric acid, which can then fall to the Earth's surface as acid rain. Therefore, the correct option is "Acid rain" as SO2 is responsible for the formation of acid rain.

    Why the other options are wrong
    • B. Greenhouse effect: While SO2 is a greenhouse gas, it is not a significant contributor to the greenhouse effect. Other gases like carbon dioxide (CO2) and methane (CH4) have a more pronounced effect on trapping heat in the atmosphere.
    • C. Global warming: Similar to the greenhouse effect, SO2 is not a significant contributor to global warming. The main greenhouse gases responsible for global warming are CO2, CH4, and nitrous oxide (N2O).
    • D. Ozone depletion: SO2 does not directly contribute to ozone depletion. Ozone depletion is primarily caused by the release of chlorofluorocarbons (CFCs) and halons, which break down ozone molecules in the upper atmosphere.

    Q124. The isomerism exhibits by C2H11OH is:

    • A. Position isomerism
    • B. Functional group isomerism
    • C. Chain isomerism
    • D. All of above

    Explanation: Position isomerism: C2H11OH, which represents a molecule with two carbon atoms, exhibits position isomerism. This is because the hydroxyl group (-OH) can be located on either of the two carbon atoms, resulting in different structural isomers. Therefore, the correct option is "Position isomerism" as C2H11OH can exhibit different structural isomers based on the position of the hydroxyl group.

    Why the other options are wrong
    • B. Functional group isomerism: C2H11OH does not exhibit functional group isomerism. Functional group isomerism occurs when molecules have the same molecular formula but different functional groups.
    • C. Chain isomerism: C2H11OH does not exhibit chain isomerism. Chain isomerism occurs when molecules have the same molecular formula but different arrangements of the carbon chain.

    Q125. When the nitrates of Na,Li,Ca and Sr were heated strongly in separate containers, all of them gave reddish brown colour except the nitrate of:

    • A. Na
    • B. Ca
    • C. Sr
    • D. Li

    Explanation: LiNO₃ → gives Li₂O + NO₂ (brown gas) + O₂.ng.

    Why the other options are wrong
    • A. Na: NaNO₃ → gives NaNO₂ + O₂ (no brown gas).
    • B. Ca: The nitrate of calcium (Ca(NO3)2) will produce a reddish-brown color upon heating due to the formation of nitrogen dioxide gas.
    • C. Sr: The nitrate of strontium (Sr(NO3)2) will produce a reddish-brown color upon heating due to the formation of nitrogen dioxide gas.

    Q126. Carboxylic acid contains:

    • A. Hydroxyl group
    • B. A hydroxyl group and carboxyl group
    • C. A carboxyl group
    • D. A carboxyl and aldehyde group

    Explanation: A carboxyl group: This option is correct. Carboxylic acids are organic compounds that contain a carboxyl group (−COOH). The carboxyl group consists of a carbonyl group (C=O) and a hydroxyl group (−OH) attached to the same carbon atom. Therefore, the correct option is that carboxylic acids contain a carboxyl group.

    Why the other options are wrong
    • A. Hydroxyl group: Carboxylic acids do not contain only a hydroxyl group. A hydroxyl group consists of an oxygen atom bonded to a hydrogen atom, while carboxylic acids have a carboxyl group, which is different in structure.
    • B. A hydroxyl group and carboxyl group: This option is incorrect. Carboxylic acids contain a carboxyl group, which consists of a carbonyl group (C=O) and a hydroxyl group (−OH) attached to the same carbon atom.
    • D. A carboxyl and aldehyde group: Carboxylic acids do not contain an aldehyde group. An aldehyde group consists of a carbonyl group (C=O) bonded to a hydrogen atom, while carboxylic acids have a carboxyl group (−COOH) instead.

    Q127. A catalyst is more effective when it is in the finely divided state because:

    • A. The valence electrons are easily available
    • B. This increases the surface area of the catalyst
    • C. It attains equilibrium quickly
    • D. All of the above

    Explanation: Option b is correct. A catalyst is more effective when it is in the finely divided state because it increases the surface area of the catalyst. This allows more reactant molecules to come into contact with the catalyst, increasing the likelihood of successful collisions and hence speeding up the reaction.

    Why the other options are wrong
    • A. This option is incorrect because the effectiveness of a catalyst is not primarily related to the availability of valence electrons.
    • C. This option is incorrect because the finely divided state of a catalyst does not necessarily have a direct impact on the attainment of equilibrium. The speed of reaching equilibrium is more related to the reaction kinetics and thermodynamics, which may be influenced by the presence of a catalyst, but not by its state of division.
    • D. This option is incorrect as only option b is correct.

    Q128. The outer electronic configuration of an element "X"bis ns2 np2. It belongs to which group of periodic table:

    • A. 2nd group
    • B. 4th group
    • C. 3rd group
    • D. 5th group

    Explanation: The outer electronic configuration of element "X" is ns2 np2, indicating that it has 2 electrons in the s subshell and 2 electrons in the p subshell of its outermost energy level. Based on this configuration, element "X" belongs to the 4th group of the periodic table. In the periodic table, groups are organized based on the number of valence electrons, and the 4th group consists of elements with 4 valence electrons.

    Why the other options are wrong
    • A. The electronic configuration of 2nd group elements is ns2.
    • C. The electronic configuration of group 3 is ns1.
    • D. The electronic configuration of 5th group is ns2 np1.

    Q129. Which one of the following is used as a drying agent?

    • A. NaHCO3
    • B. CaCO3.H2O
    • C. CaCl2 anhydrous
    • D. Na2SO4.H2O

    Explanation: CaCl2 (anhydrous calcium chloride): Calcium chloride is a widely used drying agent due to its strong hygroscopic properties. It effectively absorbs moisture from the air, making it useful for drying applications in laboratories, industries, and even for de-icing roads.

    Why the other options are wrong
    • A. NaHCO3 (sodium bicarbonate): Sodium bicarbonate is not commonly used as a drying agent. It is primarily used as a leavening agent in baking due to its ability to release carbon dioxide when heated.
    • B. CaCO3·H2O (calcium carbonate monohydrate): Calcium carbonate monohydrate is not typically used as a drying agent. It is commonly found in nature as limestone and is used in various industries such as construction and pharmaceuticals.
    • D. Na2SO4·H2O (sodium sulfate decahydrate): Sodium sulfate decahydrate is not commonly used as a drying agent. It is often used in the chemical industry for various applications, including as a laboratory reagent and in the manufacturing of detergents.

    Q130. Super Phosphate is made by:

    • A. The acidulation of phosphate rock
    • B. The alkylation of phosphate rock
    • C. The alcoholation of phosphate rock
    • D. The alkali addition of phosphate rock

    Explanation: The correct answer is A: "The acidulation of phosphate rock." Superphosphate is a fertilizer that is commonly used to provide plants with phosphorus, an essential nutrient for plant growth. It is made by treating phosphate rock with sulfuric acid in a process known as acidulation. This process converts the insoluble phosphate in the rock into a more soluble form that can be absorbed by plants.

    Why the other options are wrong
    • B. "The alkylation of phosphate rock" is not the correct answer. Alkylation involves the addition of alkyl groups to a compound and is not a process that is used to make superphosphate.
    • C. "The alcoholation of phosphate rock" is also not the correct answer. Alcoholation involves the addition of an alcohol group to a compound and is not a process that is used to make superphosphate.
    • D. "The alkali addition of phosphate rock" is not the correct answer. The addition of alkali to phosphate rock would not result in the formation of superphosphate. The acidulation process is necessary to convert the insoluble phosphate in the rock into a more soluble form.

    Q131. Which one of the following is strongest acid?

    • A. CH2Cl_CH2-COOH
    • B. CHCl2_COOH
    • C. CH3_COOH
    • D. CH3-CH2-COOH

    Explanation: In this case, the acidity of the carboxylic acids can be compared based on the stability of their corresponding conjugate bases. The more stable the conjugate base, the stronger the acid. Therefore, option B (CHCl2-COOH) is the strongest acid among the given options.

    Why the other options are wrong
    • A. (CH2Cl-CH2-COOH) is weaker than option B because the presence of the chlorine atom in the alpha position destabilizes the conjugate base, reducing the acidity.
    • C. (CH3-COOH) is weaker than option B as it lacks the electron-withdrawing effect of the chlorine atoms, which contributes to the stability of the conjugate base.
    • D. (CH3-CH2-COOH) is weaker than option B due to the absence of the chlorine atoms, which reduces the electron-withdrawing effect and the stability of the conjugate base.

    Q132. Identify the compound formed when ethylene combines with water in the presence of 10% sulphuric acid and HgSO4 as a catalyst:

    • A. Carbonal
    • B. Methanol
    • C. Ethanol
    • D. Glycol

    Explanation: (D) is correct because the product of this reaction is ethylene glycol, which is a colorless, odorless, and slightly viscous liquid. Ethylene glycol is commonly used as a coolant in automotive engines, as a solvent in the chemical industry. The reaction between ethylene and water is an example of an addition reaction. The presence of sulfuric acid and HgSO4 as a catalyst helps to initiate the reaction and increase the reaction rate.

    Why the other options are wrong
    • A. (A) is incorrect because carbonal is not a compound formed by the reaction of ethylene with water.
    • B. (B) is incorrect because methanol is not formed by the reaction of ethylene with water. Methanol can be produced by the reaction of carbon monoxide and hydrogen.
    • C. (C) is incorrect because ethanol is also not formed by the reaction of ethylene with water. Ethanol is typically produced by the fermentation of sugars in the presence of yeast.

    Q133. Catenation is a process in which carbon shows the properties of making

    • A. Multiple bonds
    • B. Hybridization
    • C. Long chain or rings of carbon atom
    • D. Showing isomerism

    Explanation: C (long chain or rings of carbon atom) is the correct answer as it specifically describes the process of catenation, where carbon atoms can form long chains or rings through covalent bonding.

    Why the other options are wrong
    • A. A, multiple bonds, is a general property of carbon, but it does not specifically describe the process of catenation. Carbon can form multiple bonds with other elements such as oxygen, nitrogen, and halogens.
    • B. B, hybridization, is the concept that explains the mixing of atomic orbitals to form hybrid orbitals in order to accommodate the bonding in carbon compounds. Hybridization is related to the geometry of carbon compounds but is not directly related to catenation.
    • D. showing isomerism, is a property of carbon compounds where different compounds have the same molecular formula but different structural arrangements. Isomerism can occur due to different types of bonding and arrangement of atoms, but it is not exclusive to catenation.

    Q134. Silver nitrate solution turns blue when a piece of copper is added to it. This is because of :

    • A. Oxidation of Ag
    • B. Reduction of Cu
    • C. Oxidation of Cu
    • D. Reduction of Ag

    Explanation: When a piece of copper is added to a silver nitrate solution, a redox reaction occurs. The copper atoms in the solid piece of copper lose electrons, which are transferred to the silver ions (Ag+) in the silver nitrate solution. As a result, the silver ions are reduced to metallic silver, which deposits on the surface of the copper. The overall reaction can be represented as follows: 2AgNO3 (aq) + Cu (s) -> Cu(NO3)2 (aq) + 2Ag (s) The blue color observed in the solution is due to the formation of copper(II) nitrate (Cu(NO3)2) in the solution. The deposition of metallic silver on the copper surface gives it a characteristic silver color.

    Why the other options are wrong
    • A. This option is incorrect because the reaction between silver nitrate and copper does not involve the oxidation of silver (Ag). Instead, it involves the reduction of silver ions (Ag+) to form metallic silver (Ag) on the surface of the copper.
    • C. This option is also incorrect. Copper (Cu) is not being oxidized in this reaction. Instead, copper atoms from the solid piece of copper are losing electrons to reduce silver ions (Ag+) from the silver nitrate solution.
    • D. This option is incorrect as well. The reaction between silver nitrate and copper results in the reduction of silver ions (Ag+) from the silver nitrate solution to form metallic silver (Ag) on the surface of the copper.

    Q135. In which of the following solvents are alkenes the most soluble?

    • A. water
    • B. ethyl alcohol
    • C. ammonia
    • D. carbon tetrachloride

    Explanation: CCl4 is non polar so alkene dissolves in it best LIKE DISSOLVES LIKE. As, alkenes is non polar so it will dissolve in non polar solvent

    Why the other options are wrong
    • A. water is polar
    • B. ethyl alcohol is polar
    • C. ammonia is also polar

    Q136. Calculate the volume occupied by 2.8 g of nitrogen gas at STP is:

    • A. 22.4 dm3
    • B. 2.24 dm3
    • C. 4.48 dm3
    • D. 44.8 dm3

    Explanation: Moles of N 2 =2.8/28=0.1 moleAtS.T.P: mole→22.4 L ∴0.1 mole →2.24 L=2240 ml=2240cc=2.24 dm3

    Why the other options are wrong

      Q137. Continuous adsorption spectrum is obtained from:

      • A. excited atoms
      • B. Excited molecules
      • C. Ground state molecules
      • D. Ground state atoms

      Explanation: Excited atoms: When atoms are excited, either by heating or by other means such as electrical discharge, they absorb energy and transition to higher energy levels. As these excited atoms return to their ground state, they emit energy in the form of electromagnetic radiation. The absorption and emission of specific wavelengths of light result in a continuous adsorption spectrum. In summary, a continuous adsorption spectrum is obtained from excited atoms, where the absorption of energy and subsequent emission of light results in a continuous range of wavelengths.

      Why the other options are wrong
      • B. Excited molecules: Molecules can also be excited and emit or absorb specific wavelengths of light, resulting in characteristic absorption or emission spectra. However, these spectra typically exhibit discrete lines rather than a continuous spectrum.
      • C. Ground state molecules: Ground state molecules refer to molecules in their lowest energy state. Since they are not in an excited state, they do not exhibit characteristic absorption or emission spectra.
      • D. Ground state atoms: Similar to ground state molecules, ground state atoms are in their lowest energy state and do not exhibit characteristic absorption or emission spectra.

      Q138. In a reaction of ethane and hydrochloric acid, the hydrogen ions act as:

      • A. nucleophiles
      • B. electrophiles
      • C. carbon ions
      • D. carbonium ions

      Explanation: Electrophiles: Electrophiles are electron-deficient species that accept a pair of electrons to form a new chemical bond. Hydrogen ions (H+) in hydrochloric acid act as electrophiles since they are positively charged and can accept a pair of electrons from another species during a reaction. Therefore, in the reaction of ethane and hydrochloric acid, the hydrogen ions (H+) act as electrophiles by accepting a pair of electrons during the reaction.

      Why the other options are wrong
      • A. Nucleophiles: Nucleophiles are electron-rich species that donate a pair of electrons to form a new chemical bond. Hydrogen ions (H+) in hydrochloric acid do not act as nucleophiles because they are electron-deficient and do not have a lone pair of electrons to donate.
      • C. Carbon ions: Carbon ions are species that contain a carbon atom with a net positive or negative charge. In the reaction of ethane and hydrochloric acid, hydrogen ions do not form carbon ions. Carbon ions may be involved in other reactions but not in the given reaction.
      • D. Carbonium ions: Carbonium ions are positively charged organic ions that contain a trivalent carbon atom. In the reaction of ethane and hydrochloric acid, hydrogen ions do not form carbonium ions. Carbonium ions may be formed in other reactions but not in this specific reaction.

      Q139. Which of the following has the least wavelength?

      • A. Alpha rays
      • B. X_rays
      • C. Cosmic rays
      • D. Beta rays

      Explanation: Cosmic rays are high-energy particles that come from outside our solar system. They can have a wide range of energies and wavelengths, depending on their source.

      Why the other options are wrong
      • A. Alpha rays are a type of radiation that consist of alpha particles, which are made up of two protons and two neutrons. They have a relatively large size compared to other types of radiation, which means they have a low penetrating power and can be stopped by a piece of paper or even the outer layer of skin. However, they can be harmful if ingested or inhaled.
      • B. X-rays are a type of electromagnetic radiation with a shorter wavelength than visible light. They have a higher penetrating power than alpha particles and can be used for medical imaging, but they can also be harmful in large doses.
      • D. Beta rays are a type of radiation that consist of beta particles, which are high-energy electrons or positrons. They have a smaller size than alpha particles, which means they have a higher penetrating power and can pass through materials like glass or aluminum. They can also be harmful if ingested or inhaled.

      Q140. Which of the following property of light does not depend upon the nature of medium?

      • A. Velocity
      • B. Wavelength
      • C. Frequency
      • D. Amplitude

      Explanation: The frequency of light does not change when light travels from one medium to another.

      Why the other options are wrong
      • A. It propagate through a medium with compression and rarefaction. This compression and rarefaction of a wave depend on the medium
      • B. The speed of light in a medium is less than in vacuum, which means that the same frequency will correspond to a shorter wavelength in the medium than in vacuum
      • D. The amplitude of the free vibration is affected by the medium. The medium of the vibration offers the resistance to the vibration wave generated by the body which consumes some energy of the wave

      Q141. The index of refraction of light in medium and vacuum is given by?

      • A. n=c/v
      • B. n=v/c
      • C. n=vc
      • D. n=v.c

      Explanation: This formula represents the index of refraction (n) of a medium, where c is the speed of light in a vacuum, and v is the speed of light in the medium. This formula is based on Snell's law, which relates the angle of incidence and refraction as light passes through a boundary between two different materials.

      Why the other options are wrong
      • B. This formula represents the reciprocal of the previous formula, where n is now the index of refraction of a vacuum, and v/c represents the ratio of the speed of light in a medium to the speed of light in a vacuum. This formula is often used to compare the refractive properties of different materials.
      • C. This formula is not a valid expression for the index of refraction, since it multiplies the speed of light in a vacuum (c) with an arbitrary velocity (v). The index of refraction is a dimensionless quantity that relates the phase velocity of light in a material to its phase velocity in a vacuum.
      • D. This formula is similar to the previous one, but with the velocity factors swapped. Again, this is not a valid expression for the index of refraction.

      Q142. The particle carrying a charge of (2e) falls through a potential difference of 3V. Energy required by the particle is:

      • A. 9.6 × 10^-19J
      • B. 1.6 ×10^-19 J
      • C. 3.2 ×10^-19 J
      • D. 6.9 × 10^-19 J

      Explanation: K.E = (1.6 ×10^-19) × (C×V) As K.E = (1.6×10^-19) (2×3) = 9.6 × 10^-19 JA.9.6 × 10^-19 J: This is the correct answer, obtained by using the equation E = qV and substituting the values given in the question.

      Why the other options are wrong
      • B. 1.6 × 10^-19 J: This is the value of the charge of a single electron (e), not the energy required by the particle.
      • C. 3.2 × 10^-19 J: This is twice the value of the charge of a single electron (2e), but does not take into account the potential difference through which the particle falls.
      • D. 6.9 × 10^-19 J: This is a value between 3.2 × 10^-19 J and 9.6 × 10^-19 J, but is not the correct answer. The energy required by the particle is directly proportional to the potential difference, so a larger potential difference would result in a larger energy requirement.

      Q143. The ratio of heat accepted to the heat rejected by a carnot engine gives :

      • A. The efficiency of the working substance
      • B. The ideal gas scale temperature
      • C. The thermal conductivity at the working substance
      • D. None of the above

      Explanation: The ratio of heat accepted to the heat rejected by a Carnot engine gives the efficiency of the working substance. A Carnot engine is a theoretical heat engine that operates on the reversible Carnot cycle. It consists of two isothermal and two adiabatic processes. The efficiency of a Carnot engine depends only on the temperatures of the hot and cold reservoirs, and is given by the Carnot efficiency formula: Efficiency = 1 - (Temperature of the cold reservoir / Temperature of the hot reservoir) The heat accepted is the heat energy absorbed by the engine from the hot reservoir, and the heat rejected is the heat energy expelled by the engine to the cold reservoir. The ratio of heat accepted to heat rejected is equal to the ratio of the absolute temperatures of the hot and cold reservoirs. Therefore, we can rewrite the Carnot efficiency formula as: Efficiency = 1 - (Temperature of the cold reservoir / Temperature of the hot reservoir) Efficiency = 1 - (Heat rejected / Heat accepted) So, the ratio of heat accepted to heat rejected by a Carnot engine gives the efficiency of the working substance. Therefore, the correct option is (a) - the ratio of heat accepted to heat rejected by a Carnot engine gives the efficiency of the working substance.

      Why the other options are wrong
      • B. (b) is incorrect because the ideal gas scale temperature is defined by the temperature-pressure relationship of an ideal gas, and is not related to the efficiency of a Carnot engine.
      • C. (c) is incorrect because the thermal conductivity of the working substance is a material property and is not related to the efficiency of a Carnot engine.

      Q144. The speed of particle at the end of four successes seconds is 20,25,30, 35km/hr, the acceleration of the particle is:

      • A. 5km/hr²
      • B. 5km/sec²
      • C. 5km_hr/sec
      • D. 5km/hr_sec

      Explanation: The acceleration of the particle cannot be determined with the given information. Acceleration is defined as the rate of change of velocity with respect to time. The formula for acceleration is: a = (v₂ - v₁) / (t₂ - t₁) where: a is the acceleration v₂ and v₁ are the final and initial velocities, respectively t₂ and t₁ are the final and initial times, respectively In this case, we are given the final velocities of the particle after four successive seconds as 20, 25, 30, and 35 km/hr, but we do not have the initial velocities or the times at which these velocities were measured. Therefore, we cannot calculate the acceleration of the particle using the above formula. Option (a) is incorrect because it represents acceleration in units of km/hr², which is not a standard unit of acceleration. The SI unit of acceleration is m/s². Therefore, the correct answer is that the acceleration of the particle cannot be determined with the given information.

      Why the other options are wrong
      • B. (b) is incorrect because it represents acceleration in units of km/sec², which is a much larger unit than the standard SI unit of acceleration.
      • C. (c) is incorrect because it represents a combination of units for velocity and time, but not for acceleration.
      • D. (d) is incorrect because it represents a combination of units for velocity and time, but not for acceleration.

      Q145. The orbital speed of satellite orbiting around the Earth is:

      • A. √GM/Re
      • B. √GMe/Re
      • C. √GMe/R²
      • D. √GMe/h

      Explanation: The correct formula to calculate the orbital speed (v) of a satellite orbiting the Earth is: v = √(GMe/r) where G is the gravitational constant, Me is the mass of the Earth, and r is the distance between the center of the Earth and the satellite. To derive this formula, we can start with the centripetal force equation F = m v² / r G (Me * m) / r² = m v² / r Solving for v, we get: v = √(GMe/r)

      Why the other options are wrong
      • A. (√GM/Re) only considers the mass of the Earth (M) and the radius of the satellite's orbit (R), but does not take into account the mass of the satellite (m). The correct formula for orbital speed should involve the mass of the satellite as well. Therefore, option A is incomplete and incorrect.
      • C. (√GMe/R²) uses the correct mass of the Earth (Me), but the formula is incorrect. This formula calculates the acceleration due to gravity at a distance R from the center of the Earth, but it does not give the orbital speed of a satellite. Therefore, option C is incorrect.
      • D. (√GMe/h) uses h instead of R, which is incorrect. h is usually used to denote the altitude or height of the satellite above the Earth's surface, but the formula for orbital speed requires the distance from the center of the Earth (R). Therefore, option D is incorrect.

      Q146. If n^ is unit vector in direction of A→ then:

      • A. n^= A→/|A|
      • B. n^= (A.|A|)—
      • C. n^= n^A→
      • D. n^= A/A—

      Explanation: n^= A→/|A|: This equation represents the unit vector n^ in the direction of the vector A→. To obtain n^, we divide the vector A→ by its magnitude |A|, which gives us the direction of the vector without changing its magnitude. Overall, the correct equation for the unit vector n^ in the direction of the vector A→ is n^= A→/|A|. This equation gives us the direction of the vector A→ without changing its magnitude, as the unit vector has a magnitude of 1.

      Why the other options are wrong
      • B. n^= (A.|A|)— : This equation is incorrect and does not represent the unit vector n^ in the direction of A→.
      • C. n^= n^A→ : This equation is also incorrect and does not represent the unit vector n^ in the direction of A→
      • D. n^= A/A— : This equation is also incorrect and does not represent the unit vector n^ in the direction of A→

      Q147. The value of K (equilibrium constant) for a reaction?

      • A. Is the same at different temperature?
      • B. Is different at different temperature
      • C. Is negligible at room temperature
      • D. Can be same at different temperatures

      Explanation: The value of K (equilibrium constant) for a reaction can be different at different temperatures. This is because the equilibrium constant depends on the temperature of the reaction. According to the Arrhenius equation, the rate constant of a reaction increases with an increase in temperature. Therefore, the value of K changes with a change in temperature. Therefore, the value of K for a reaction is dependent on the temperature of the reaction and the enthalpy change of the reaction.

      Why the other options are wrong
      • C. The equilibrium constant can also be negligible at room temperature if the reaction is highly endothermic or exothermic. In such cases, the activation energy barrier can be very high, and the reaction may not proceed significantly at room temperature, resulting in a negligible equilibrium constant.
      • D. However, it is possible for the equilibrium constant to be the same at different temperatures, but this is not always the case. This usually occurs when the reaction is neither exothermic nor endothermic and the change in enthalpy of the reaction is zero.

      Q148. Horizontal range of projectile is:

      • A. R= V²sin∅ Cos∅/g
      • B. R= V²i Sin ∅/2g
      • C. R = V² Sin (2∅)/g
      • D. R= V² i sin ∅ (2∅)/g

      Explanation: The correct equation for the horizontal range of a projectile is: R = V²sin(2∅)/g where: R is the horizontal range of the projectile (the distance traveled horizontally) V is the initial velocity of the projectile ∅ is the angle of projection (the angle between the initial velocity and the horizontal) g is the acceleration due to gravity.

      Why the other options are wrong
      • A. A is incorrect because it includes an additional term of Cos∅, which is not part of the equation for horizontal range.
      • B. B is incorrect because it includes an additional factor of 2 in the denominator, which is not part of the equation for horizontal range.
      • D. D is incorrect because it includes an incorrect term of sin ∅ (2∅), which is not part of the equation for horizontal range.

      Q149. The resistance of the pure semiconductor decreases in a certain ratio with the?

      • A. Decrease in temperature
      • B. Increase in current
      • C. Increase in temperature
      • D. Decrease in current

      Explanation: In a pure semiconductor, the resistance decreases with an increase in temperature. This happens because as temperature increases, some electrons in the valence band gain enough energy to jump to the conduction band, leaving behind holes in the valence band. This increases the number of charge carriers in the material, leading to a decrease in resistance.

      Why the other options are wrong
      • A. On the other hand, the resistance of a pure semiconductor increases with a decrease in temperature. This happens because at lower temperatures, there is a decrease in the number of electrons in the valence band that have enough energy to jump to the conduction band, resulting in fewer charge carriers and an increase in resistance.
      • B. An increase in current does not affect the resistance of a pure semiconductor. The resistance of a semiconductor is dependent on its intrinsic properties and is not affected by external factors such as current.
      • D. Lastly, a decrease in current does not affect the resistance of a pure semiconductor. The resistance is determined by the number of charge carriers and their mobility within the material, which is a property of the material itself and is not affected by the magnitude of the current flowing through it.

      Q150. The paratrooper of mass 80 kg descends vertically at a constant velocity of 3.0 ms-¹ . Taking the acceleration of free fall as 10 ms-¹ find out what is the net force acting on him? (g=10ms-²)

      • A. Zero
      • B. 800 N upward
      • C. 800 N downward
      • D. 24 N downward

      Explanation: The net force is zero bcz there is no acceleration. The strings of parachute are pulling against him in the upward direction with a force equal to his weight which is equal and opposite to his weight due to pull of gravity downward.

      Why the other options are wrong

        Q151. The acceleration of falling body in fluid depends upon:

        • A. Velocity
        • B. Viscosity of fluid
        • C. Density of the body
        • D. All of above

        Explanation: When a body falls through a fluid, it experiences a resistance force due to the viscosity of the fluid. This resistance force opposes the motion of the body and causes it to slow down. As a result, the acceleration of the body decreases over time until it reaches a terminal velocity. Therefore, all of the above factors - velocity, viscosity of the fluid, and density of the body - influence the acceleration of a falling body in a fluid.

        Why the other options are wrong
        • A. The acceleration of a falling body in a fluid depends on its velocity. Initially, when the body is falling at a high velocity, the resistance force due to viscosity is also high, resulting in a large deceleration. As the velocity of the body decreases due to the deceleration, the resistance force decreases, and the body's acceleration also decreases.
        • B. Viscosity of the fluid: The resistance force due to viscosity is directly proportional to the viscosity of the fluid. Therefore, the acceleration of a falling body in a fluid depends on the viscosity of the fluid. A more viscous fluid will cause a greater resistance force, resulting in a greater deceleration and a lower terminal velocity.
        • C. Density of the body: The acceleration of a falling body in a fluid also depends on the density of the body. A more dense body will experience a greater gravitational force, resulting in a higher acceleration. However, the resistance force due to viscosity will also be greater, resulting in a lower terminal velocity.

        Q152. Two concurrent forces have a maximum resultant of 45N and minimum resultant of 5N. What is the magnitude of each of these?

        • A. 0.45N
        • B. 5N,9N
        • C. 20N,25N
        • D. 0N,45N

        Explanation: maximum resultant: 45 = a + b minimum resultant: 5 = a - b Solve for a in the first equation then substitute it into the second equation: a = 45 - b 5 = 45 - b -b 5 - 45 = -2b -40 = -2b 20 = b Since we know the value for b we can substitute it into the first equation to find the value for a: 45 = a + 20 45 - 20 = a 25 = a So the magnitude of each of these forces are 20N, 25N Therefore, the answer is option C: 20N and 25N, as they give the maximum resultant of 45N and fall within the range of values required by the problem.

        Why the other options are wrong
        • A. 0.45N is not a possible answer as it is smaller than the minimum resultant given in the problem.
        • B. 5N and 9N are the magnitudes of the two concurrent forces that give the minimum resultant of 5N. However, we need to find the maximum resultant as well.
        • D. 0N and 45N are not possible values as it would mean one of the concurrent forces has zero magnitude, which is not possible as two concurrent forces must have non-zero magnitudes.

        Q153. The direction of torque is:

        • A. Parallel to the plane of F and γ
        • B. Perpendicular to the plane of F and γ
        • C. Anti parallel to the plane of F and γ
        • D. Is the same as that of the plane of F and γ

        Explanation: Perpendicular to the plane of F and γ: This option is correct as torque is always perpendicular to the plane defined by the force vector and the position vector from the axis of rotation to the point where the force is applied (i.e., γ).

        Why the other options are wrong
        • A. Parallel to the plane of F and γ: This option is incorrect as torque is not parallel to the plane of F and γ.
        • C. Antiparallel to the plane of F and γ: This option is incorrect as torque is not antiparallel to the plane of F and γ.
        • D. Is the same as that of the plane of F and γ: This option is incorrect as torque is always perpendicular to the plane defined by the force vector and the position vector from the axis of rotation to the point where the force is applied (i.e., γ).

        Q154. How are the two vectors of the same magnitude oriented to get a resultant of the same magnitude?

        • A. 90°
        • B. 60°
        • C. 45°
        • D. 120°

        Explanation: 120°: If two vectors of the same magnitude are oriented at 120 degrees to each other, the resultant vector will have a magnitude that is greater than the individual vectors. The magnitude of the resultant vector can be calculated using the law of cosines: magnitude of resultant = sqrt(magnitude of individual vector^2 + magnitude of individual vector^2 - 2 * magnitude of individual vector * magnitude of individual vector * cos(θ)) Where θ is the angle between the vectors. In this case, since θ is 120 degrees, the resultant vector will have a magnitude that is greater than the magnitude of each individual vector.

        Why the other options are wrong
        • A. 90°: When two vectors of the same magnitude are oriented at 90 degrees to each other, the resultant vector will also have the same magnitude. This scenario occurs when the vectors are perpendicular to each other, forming a right angle. The magnitude of the resultant vector can be calculated using the Pythagorean theorem.
        • B. 60°: If two vectors of the same magnitude are oriented at 60 degrees to each other, the resultant vector will have a magnitude that is greater than the individual vectors. The resultant vector's magnitude is given by the formula: magnitude of resultant = 2 * magnitude of individual vector * cos(θ/2) Where θ is the angle between the vectors. In this case, since θ is 60 degrees, the resultant vector will have a magnitude that is twice the magnitude of each individual vector.
        • C. 45°: When two vectors of the same magnitude are oriented at 45 degrees to each other, the resultant vector will also have the same magnitude. This scenario occurs when the vectors are at an angle of 45 degrees, forming an isosceles right triangle. The magnitude of the resultant vector can be calculated using the Pythagorean theorem.

        Q155. Rain drops falling from sky reach the ground with?

        • A. Constant acceleration
        • B. Constant terminal velocity
        • C. Acceleration greater than g
        • D. Variable acceleration

        Explanation: When raindrops fall from the sky, they experience various forces and factors that affect their motion. Let's explore each option in relation to the motion of raindrops: Constant terminal velocity: This option is correct. Raindrops falling from the sky eventually reach a state where the drag force due to air resistance equals the force of gravity. At this point, the raindrop achieves a constant terminal velocity. Terminal velocity is the maximum velocity a falling object can reach when the drag force equals the gravitational force pulling it downward. Raindrops, being relatively small and having a high surface-to-volume ratio, experience significant air resistance, which ultimately limits their acceleration and causes them to fall with a constant terminal velocity. In summary, raindrops falling from the sky reach the ground with a constant terminal velocity once they have reached a point where the drag force due to air resistance balances the force of gravity.

        Why the other options are wrong
        • A. Constant acceleration: This option is incorrect. Raindrops do not fall with constant acceleration. Initially, when a raindrop starts falling, it experiences acceleration due to gravity (9.8 m/s² near the Earth's surface). However, as the raindrop falls and gains speed, it eventually reaches a point where the gravitational force and the drag force due to air resistance balance each other. At this point, the raindrop reaches its terminal velocity, as explained in the next option.
        • C. Acceleration greater than g: This option is incorrect. The acceleration experienced by falling raindrops is initially equal to the acceleration due to gravity, which is approximately 9.8 m/s² near the Earth's surface. However, as explained earlier, the acceleration decreases as the raindrop reaches its terminal velocity, but it does not exceed the acceleration due to gravity.
        • D. Variable acceleration: This option is incorrect. While the acceleration of raindrops is initially equal to the acceleration due to gravity, it becomes constant once the raindrop reaches its terminal velocity. After that point, there is no further acceleration, and the raindrop falls with a constant velocity.

        Q156. Potentiometer is the instrument working on the principle of:

        • A. Kirchholf's 1st law
        • B. Wheatstone bridge
        • C. Combination of resistance
        • D. Kirchholf's 2nd law

        Explanation: Wheatstone Bridge: The Wheatstone bridge is a circuit arrangement consisting of four resistive elements connected in a diamond shape. It operates based on the principle of null detection, where the bridge is balanced by adjusting one of the resistances until the potential difference across the central point of the bridge is zero. The potentiometer uses the Wheatstone bridge principle to measure unknown voltages or to compare and calibrate resistances. In conclusion, the potentiometer is an instrument that works based on the principle of the Wheatstone bridge, which involves the balancing of resistances to measure unknown voltages or compare resistances accurately.

        Why the other options are wrong
        • A. Kirchhoff's 1st Law (Kirchhoff's Current Law): This law states that the algebraic sum of currents at any junction in an electrical circuit is zero. It deals with the conservation of electric charge. However, the potentiometer does not directly rely on Kirchhoff's 1st Law for its operation.
        • C. Combination of Resistance: The potentiometer does involve the use of resistances in its construction and operation. However, it is more accurate to say that the potentiometer utilizes the Wheatstone bridge circuit, which is a specific arrangement of resistances, rather than a generic combination of resistances.
        • D. Kirchhoff's 2nd Law (Kirchhoff's Voltage Law): This law states that the sum of the electromotive forces (EMFs) and voltage drops in any closed loop of an electrical circuit is zero. Like Kirchhoff's 1st Law, Kirchhoff's 2nd Law is not directly applicable to the principle of operation of a potentiometer.

        Q157. The density of steal ball was determined by measuring the mass and diameter. The mass was measured with 1% and diameter 3% of the error. In the calculated density of the steel ball is at most;

        • A. 2%
        • B. 8%
        • C. 4%
        • D. 10%

        Explanation: 4%: As mentioned earlier, the maximum error in the calculated density is the sum of the errors in measuring the mass and diameter, which is 1% + 3% = 4%. Therefore, the maximum error in the calculated density is 4%. Based on the analysis, the option that correctly represents the maximum error in the calculated density of the steel ball is 4%.

        Why the other options are wrong
        • A. 2%: If the mass is measured with a 1% error and the diameter is measured with a 3% error, the maximum error in the calculated density would be the sum of these two errors, which is 1% + 3% = 4%. Therefore, the maximum error in the calculated density exceeds 2%.
        • B. 8%: If the maximum error in measuring both the mass and diameter was 8%, this would imply a 4% error for each measurement. However, since each individual measurement has a smaller error (1% for mass and 3% for diameter), the maximum error in the calculated density would be less than 8%. Therefore, the maximum error in the calculated density is not 8%.
        • D. 10%: If the maximum error in measuring both the mass and diameter was 10%, this would imply a 5% error for each measurement. Since the actual errors in this case (1% for mass and 3% for diameter) are smaller than 5%, the maximum error in the calculated density would be less than 10%. Therefore, the maximum error in the calculated density is not 10%.

        Q158. Two vectors A→ and B→ are such that |A+B|→ = |A-B|→. The angle between the two vectors is:

        • A.
        • B. 60°
        • C. 90°
        • D. 180°

        Explanation: 90°: If the angle between A→ and B→ is 90°, the dot product A→ · B→ would be |A→| |B→| cos(90°) = 0. This option is consistent with the given condition 2A→ · B→ = 0, as it satisfies the equation. Based on the analysis above, the angle between the two vectors A→ and B→ is 90°.

        Why the other options are wrong
        • A. 0°: If the angle between A→ and B→ is 0°, it means they are collinear, pointing in the same direction. In this case, the dot product A→ · B→ would be |A→| |B→| cos(0°) = |A→| |B→|, which is non-zero. Therefore, this option is not consistent with the given condition 2A→ · B→ = 0.
        • B. 60°: If the angle between A→ and B→ is 60°, the dot product A→ · B→ would be |A→| |B→| cos(60°) = (1/2) |A→| |B→|. This is also non-zero, so this option does not satisfy the given condition.
        • D. 180°: If the angle between A→ and B→ is 180°, it means they are collinear, but pointing in opposite directions. In this case, the dot product A→ · B→ would be |A→| |B→| cos(180°) = -|A→| |B→|, which is non-zero. Therefore, this option is not consistent with the given condition.

        Q159. If a green light in a Young double slit experiment is replaced by monochromatic orange light of the same intensity, Then:

        • A. Fringe width will decrease
        • B. Fringe width will increase
        • C. Fringe width will remain the same
        • D. Fringe width will become less intense

        Explanation: Fringe width will increase: If the orange light has a longer wavelength compared to the green light, then the fringe width will increase. In this case, the fringes become more spread out, resulting in a wider fringe pattern. This occurs because the fringe width is inversely proportional to the wavelength of light.

        Why the other options are wrong
        • A. Fringe width will decrease: The fringe width is determined by the wavelength of the light used. If the orange light has a shorter wavelength compared to the green light, then the fringe width will decrease. This is because the fringe width is inversely proportional to the wavelength of the light used in the experiment. As the wavelength decreases, the fringes become closer together, resulting in a narrower fringe pattern.
        • C. Fringe width will remain the same: If the orange light has the same wavelength as the green light, then the fringe width will remain the same. The fringe width is determined solely by the wavelength of light used in the experiment. Therefore, if the two lights have the same wavelength, the fringe width will be unchanged.
        • D. Fringe width will become less intense: The intensity of the fringes depends on the amplitude of the light waves. When replacing the green light with monochromatic orange light of the same intensity, the fringe width will not directly affect the intensity of the fringes. Therefore, the fringe width will not cause a change in the intensity of the fringes.

        Q160. Two bodies with masses m1 ans m2 have equal kinetic energies. If M1 and M2 are their respective momentum then the ratio between M1 and M2 is:

        • A. m1:m2
        • B. √m1/m2
        • C. m1²: m2²
        • D. √m1:√m2

        Explanation: The energy and momentum are related The KE is proportional to square of momentum KE = p²/2m so if two bodies have equal energy then their square of momentum divided by masses will be equal. Say M1 and M2 their momentum M1²/2.m1= M2²/2.m2 So M1/M2 = √m1/m2

        Why the other options are wrong
        • A. m1 : m2: This option suggests that the ratio between the masses m1 and m2 is the desired ratio. However, the ratio of masses alone does not provide enough information about the momentum.
        • C. m1² : m2²: This option suggests taking the square of the ratio of m1 to m2. Similar to option 1, this ratio involves the masses alone and does not consider the velocities or momenta of the objects. Thus, it is not the correct choice for determining the ratio between their momenta.
        • D. √m1 : √m2: This option suggests taking the square root of m1 and m2 individually to determine the ratio. However, the square root of the masses does not directly provide the ratio between their momenta.

        Q161. If frequency of incident light falling on photo emissive plate is doubled. Kinetic energy of emitted photoelectron is:

        • A. Doubled
        • B. More than double
        • C. Unchanged
        • D. Less than double

        Explanation: More than double: From Einstein's equation for photoelectric effect , the maximum kinetic energy , K=hν−W where ν= frequency of incident light , h= Planck's constant and W= work function of metal. When ν is made double, K =2hν−W=2(hν−W)+W=2K+W Thus, kinetic energy of photoelectrons will be more than doubled when incident frequency is doubled.

        Why the other options are wrong
        • A. Doubled: From Einstein's equation for photoelectric effect, the kinetic energy is K=hv-W When v is made double k” = 2hv - W = 2 (hv - W) + W = 2K + W Which is not double but more than double
        • C. Unchanged: This option is not applicable in this scenario. According to the photoelectric effect, the kinetic energy of emitted photoelectrons is directly proportional to the frequency of incident light. Doubling the frequency will lead to an increase in kinetic energy, so the kinetic energy will not remain unchanged.
        • D. Less than double: This option is not applicable in this scenario. Doubling the frequency of incident light will result in a kinetic energy of emitted photoelectrons that is greater than double. The relationship between kinetic energy and frequency is linear, so doubling the frequency will lead to a doubling of kinetic energy.

        Q162. The number of significant figures in 4.0030 is:

        • A. Four
        • B. Five
        • C. Two
        • D. Three

        Explanation: Five: There are five significant figures in 4.0030. All the digits (4, 0, 0, 3, and 0) are non-zero and the trailing zero after the decimal point indicates precision, making it significant.

        Why the other options are wrong
        • A. Four: There are four significant figures in 4.0030. All the digits (4, 0, 0, and 3) are non-zero, and the trailing zero after the decimal point indicates precision, making it significant.
        • C. Two: This option is not correct. There are more than two significant figures in 4.0030. The zeros in the number are not leading zeros, but they are between nonzero digits and are, therefore, significant.
        • D. Three: This option is not correct. There are more than three significant figures in 4.0030. The zeros in the number are not leading zeros, but they are between nonzero digits and are, therefore, significant.

        Q163. Hydrogen atom in the ground state absorbs energy from the incident photon. Which makes a transition to energy level characterized by n=4 the number of lines observed are:

        • A. 8
        • B. 4
        • C. 6
        • D. 10

        Explanation: The transition of a hydrogen atom from the ground state to an energy level characterized by n = 4 corresponds to an electron moving from the first energy level (n = 1) to the fourth energy level (n = 4).To determine the number of spectral lines observed, we can use the formula:Number of spectral lines = n(n-1)/2=4(4-1)/2=6

        Q164. An object in a satellite orbiting around the Earth is weightless because:

        • A. g=0
        • B. It is falling freely
        • C. No force acts on it
        • D. It is far away from the earth

        Explanation: No force acts on it: This option is incorrect. There is a force acting on the object due to gravity, but it is balanced by the centripetal force of the satellite's orbital motion.

        Why the other options are wrong
        • A. g = 0: This option is incorrect. The value of acceleration due to gravity (g) is not zero in space; it is simply weaker than on the surface of the Earth.
        • B. It is falling freely: This option is correct. Objects in satellite orbits are in constant free fall towards the Earth, which creates the sensation of weightlessness.
        • D. It is far away from the Earth: This option is incorrect. The sensation of weightlessness is not solely due to distance from the Earth, but rather the free-falling nature of the object in orbit.

        Q165. Light and heavy bodies have equal kinetic energies. Which one has the greater momentum?

        • A. Heavy body
        • B. Light body
        • C. Both have same momentum
        • D. None of these

        Explanation: Heavy body: Momentum is given by the product of mass and velocity. Since the heavy body has a larger mass, even if the kinetic energies are equal, its momentum would be greater due to its mass.

        Why the other options are wrong
        • B. Light body: This option is incorrect. A lighter body would have a smaller mass, resulting in a smaller momentum compared to the heavy body.
        • C. Both have the same momentum: This option is incorrect. Momentum depends on mass, and since the bodies have different masses, their momenta would be different even if their kinetic energies are equal.
        • D. The correct answer is the "Heavy body" as explained above.

        Q166. In open organ pipe of length l is the wavelength of the fundamental note is:

        • A. Equal to 1
        • B. Equal to 2L
        • C. Equal to 4L
        • D. Equal to 3l/2

        Explanation: Equal to 2L: This option is correct. In an open organ pipe, the fundamental wavelength corresponds to the length of the pipe, so the wavelength is equal to 2 times the length (2L).

        Why the other options are wrong
        • A. Equal to 1: This option is incorrect because the fundamental wavelength in an open organ pipe is not equal to 1.
        • C. Equal to 4L: This option is incorrect. The wavelength of the fundamental note in an open organ pipe is not equal to 4 times the length of the pipe.
        • D. Equal to 3l/2: This option is incorrect. The wavelength of the fundamental note in an open organ pipe is not equal to 3 times the length divided by 2.

        Q167. The time period of communication satellites is:

        • A. 1 hour
        • B. 2 hour
        • C. 12 hours
        • D. 24 hours

        Explanation: 24 hours: This option is correct. Geostationary communication satellites orbit the Earth at a height of about 35,786 kilometers, taking 24 hours to complete one orbit. This allows them to remain fixed in the sky relative to an observer on Earth, providing continuous communication coverage.

        Why the other options are wrong
        • A. 1 hour: This option is incorrect. The time period of communication satellites is not 1 hour.
        • B. 2 hours: This option is incorrect. The time period of communication satellites is not 2 hours.
        • C. 12 hours: This option is incorrect. The time period of communication satellites is not 12 hours.

        Q168. When the Newton's ring interference_ is seen from above by means of reflected light. The central spot always appears:

        • A. White
        • B. Black
        • C. Red
        • D. Green

        Explanation: Black: The central spot appears black when destructive interference occurs, causing the incident and reflected waves to cancel each other out, resulting in minimum brightness or complete darkness at the center.

        Why the other options are wrong
        • A. White: The central spot appears white because constructive interference occurs when the path difference between the incident and reflected light waves is zero, resulting in maximum brightness at the center.
        • C. Red: The central spot does not appear red. The colors observed in Newton's rings are due to interference effects between the incident and reflected light waves, resulting in constructive and destructive interference patterns. However, a specific color like red is not inherent to the central spot.
        • D. Green: The central spot does not appear green. The color observed in Newton's rings can vary depending on the light source used and the thickness of the air film between the glass surfaces, but green is not a specific color associated with the central spot.

        Q169. The unit of electric intensity is:

        • A. Volt/meter
        • B. Newton/coulomb
        • C. Joule/coulomb_meter
        • D. All of above

        Explanation: Therefore, the correct answer is "All of the above" since all the options are valid units for electric intensity, each expressing a different aspect of the electric field strength.

        Why the other options are wrong
        • A. Volt/meter (V/m): It expresses the electric field strength as the potential difference (voltage) per unit distance.
        • B. Newton/coulomb (N/C): It quantifies the electric field strength in terms of the force per unit charge.
        • C. Joule/coulomb_meter (J/C·m): This unit represents the energy per unit charge and per unit distance.

        Q170. If a wave can be polarized, it must be:

        • A. An electromagnetic wave
        • B. A stationary wave
        • C. Transverse wave
        • D. A longitudinal wave

        Explanation: Transverse waves which include all electromagnetic waves such as light, radio waves, and x-rays can be polarized, hence the answer will be C.

        Why the other options are wrong
        • A. Transverse waves that include electromagnetic waves can be polarized.
        • B. Stationary waves as the name said are stationary so polarization cannot differentiate them.
        • D. Longitudinal waves are produced by compression and rarefaction of the medium that can pass through any type of polarizer.

        Q171. The resolving power is expressed as maximum angle α min between the two sources S1 and S2 . If λ is wavelength of of light and D is diameter of lens, then the resolving power is given by:

        • A. αmin≥1.22λ/D
        • B. αm.λ/D
        • C. αmin 2.1 λ/D
        • D. αmin ≤1.22λ/D

        Explanation: αmin ≥ 1.22λ/D. This is the correct expression for resolving power, known as Rayleigh's criterion, which states that the minimum resolvable angle is at least 1.22 times the wavelength divided by the diameter of the lens. Therefore, the correct option for the resolving power is "αmin ≥ 1.22λ/D."

        Why the other options are wrong
        • B. αm.λ/D. This expression is not a valid representation of resolving power.
        • C. αmin 2.1λ/D. This expression is not a valid representation of resolving power.
        • D. αmin ≤ 1.22λ/D. This expression is incorrect because the minimum resolvable angle is not less than 1.22λ/D, but rather at least 1.22λ/D.

        Q172. Planck's constant has the dimension of:

        • A. Energy
        • B. Work
        • C. Linear momentum
        • D. Angular momentum

        Explanation: The dimension of angular momentum is M1L2T-1. This option is correct oneAngular momentum has the formula as π π L = nh / 2 π ,where is the Planck's constant. π π nh / 2 π is a constant and can be neglected during dimension calculation. Hence, Angular momentum has the same dimension as of Planck's constant

        Why the other options are wrong
        • A. While, the dimension of energy is M1L2T-2.
        • B. The dimension of work is ML2T-2. Same, as that of energy.
        • C. The dimension of linear momentum is M1L1T-1.

        Q173. The wavelength of sound made from a tuning fork of frequency 330 Hz is nearly:

        • A. 330m
        • B. 100m
        • C. 10m
        • D. 1m

        Explanation: Therefore, the correct option is "1m" as it represents a reasonable wavelength for audible sound produced by a tuning fork of frequency 330 Hz. The wavelength of sound can be calculated using the formula: wavelength = speed of sound / frequency.

        Why the other options are wrong
        • A. 330m: This option is incorrect as it represents an extremely long wavelength, which is not feasible for audible sound.
        • B. This option is also incorrect as it suggests a wavelength that is still too long for audible sound.
        • C. 10m: This option is incorrect as well, as it still represents a wavelength that is too long for audible sound.

        Q174. Pressure exerted by perfect gas is equal to :

        • A. ⅓ mean K.E/volume
        • B. ½ Mean K.E/volume
        • C. ⅔ mean K.E/volume
        • D. Mean K.E/volume

        Explanation: 2/3 mean K.E/volume: This option is correct. The pressure exerted by an ideal gas is numerically equal to two-third of the mean kinetic energy of translation per unit volume of the gas. Hence, pressure is two-third of mean KE per unit volume.

        Why the other options are wrong
        • A. 1/3 mean K.E/volume: This option is incorrect. The pressure of a perfect gas is not directly related to one-third of the mean kinetic energy divided by volume.
        • B. 1/2 mean K.E/volume: This option is incorrect. The pressure of a perfect gas is not directly related to one-half of the mean kinetic energy divided by volume.
        • D. Mean K.E/volume: This option is incorrect. The pressure of a perfect gas is not directly related to the mean kinetic energy divided by volume.

        Q175. The charge on an electron is equal to :

        • A. 1.7588×10^19 Coulomb
        • B. 1.6022×10^-19 Coulomb
        • C. 1.2057×10^19 Coulomb
        • D. 0.6022×10^19 Coulomb

        Explanation: 1.6022×10^-19 Coulomb: This option is correct. The charge of an electron is approximately -1.6022×10^-19 Coulomb.

        Why the other options are wrong
        • A. 1.7588×10^19 Coulomb: This option is incorrect. The value provided is not the charge of an electron.
        • C. 1.2057×10^19 Coulomb: This option is incorrect. The value provided is not the charge of an electron.
        • D. 0.6022×10^19 Coulomb: This option is incorrect. The value provided is not the charge of an electron.

        Q176. A particle performs simple harmonic motion of amplitude 0.02m and frequency 2.5 Hz what is the maximum speed?

        • A. 0.008m/s
        • B. 0.314m/s
        • C. 0.125m/s
        • D. 0.05m/s

        Explanation: To determine the maximum speed of a particle in simple harmonic motion with an amplitude of 0.02 m and frequency of 2.5 Hz, we can use the equation vmax = ωA, where ω is the angular frequency and A is the amplitude. 0.314 m/s: This option is correct. By substituting the values, vmax = (2π × 2.5 Hz) × 0.02 m = 0.314 m/s. Therefore, the correct option is "0.314 m/s" as it represents the maximum speed of the particle in simple harmonic motion with the given parameters.

        Why the other options are wrong
        • A. 0.008 m/s: This option is incorrect. The calculated value is incorrect.
        • C. 0.125 m/s: This option is incorrect. The calculated value is incorrect.
        • D. 0.05 m/s: This option is incorrect. The calculated value is incorrect.

        Q177. A particle of mass moving with velocity V makes head. One elastic collision with another particle of the same mass and initially at rest. The velocity of the first particle after the collision:

        • A. 2V
        • B. -V
        • C. +V
        • D. Zero

        Explanation: -V: This option is correct. In an elastic collision, the first particle will experience a change in direction and will have a velocity equal in magnitude but opposite in direction to its initial velocity. Therefore, the correct option is "-V" as the first particle will have a velocity equal in magnitude but opposite in direction to its initial velocity after the elastic collision.

        Why the other options are wrong
        • A. 2V: This option is incorrect. In an elastic collision, the relative velocity between the two particles reverses after the collision, but the magnitude of the velocity remains the same.
        • C. +V: This option is incorrect. The first particle's velocity will not simply remain the same after the elastic collision.
        • D. Zero: This option is incorrect. In an elastic collision, the momentum is conserved, so the first particle will continue to have a non-zero velocity.

        Q178. In CRO, the time bases sweep circuit is connected to the:

        • A. X_plate
        • B. Y_plate
        • C. Electron gun
        • D. Accelerating electrode

        Explanation: Accelerating electrode: This option is correct. The time base sweep circuit is connected to the accelerating electrode, which controls the speed at which the electron beam scans across the screen horizontally, creating the time base sweep.

        Why the other options are wrong
        • A. X_plate: The X_plate is incorrect. It is responsible for horizontal deflection and is used to control the position of the electron beam along the x-axis.
        • B. Y_plate: The Y_plate is incorrect. It is responsible for vertical deflection and controls the position of the electron beam along the y-axis.
        • C. Electron gun: The Electron gun is incorrect. It is responsible for producing and accelerating the electron beam.

        Q179. Ampere hour is a unit of:

        • A. Current
        • B. Time
        • C. Quantity of charge
        • D. Power

        Explanation: Quantity of charge: This option is correct. Ampere hour is a unit of the quantity of charge, representing the total charge transported by a current of one ampere in one hour.

        Why the other options are wrong
        • A. Current: This option is incorrect. Ampere hour is not a unit of current, but it is related to the flow of current over a specific time period.
        • B. Time: This option is incorrect. Ampere hour is not a unit of time, but it is used to measure the cumulative amount of charge flow over time.
        • D. Power: This option is incorrect. Ampere hour is not a unit of power, which is measured in watts.

        Q180. A 100m long conductor carrying current of 2A is at right angle to B of 0.5 wb_m² . The force experienced by the conductor is:

        • A. 1.2N
        • B. 3 dynes
        • C. 10^7 dynes
        • D. 10^5 dynes

        Explanation: This option is correct as 10^7 dynes are equal to 100N. The force can be calculated by: F = BILsinθ In this case, the cylinder is carrying a current of 2A and is placed at right angles to a magnetic field of 0.5 Wb/m². Therefore, the angle between the current and the magnetic field is 90 degrees, and sinθ = 1. Substituting the given values into the formula, we get: F = (0.5 Wb/m²) x (2 A) x (100 m) x sin 90° F = 100 N

        Why the other options are wrong
        • A. This option is incorrect as from the following derivation.
        • B. This option is also incorrect as 3 dynes are equal to 3 × 10-5 newton.
        • D. This option is incorrect as 10^5 dynes are equal to 1N.

        Q181. Which type of field is present near a moving electric charge?

        • A. An electric field only
        • B. A magnetic field only
        • C. Both magnetic and electric field
        • D. Magnetic and gravitational field

        Explanation: Magnetic and gravitational field: This option is incorrect. A moving electric charge does not generate a gravitational field. The gravitational field is associated with mass, not electric charge. Therefore, the correct option is "Both magnetic and electric field" as a moving electric charge generates both types of fields in its vicinity.

        Why the other options are wrong
        • A. An electric field only: This option is incorrect. A moving electric charge generates both an electric field and a magnetic field in its vicinity, according to Maxwell's equations.
        • B. A magnetic field only: This option is incorrect. A moving electric charge generates both an electric field and a magnetic field in its vicinity, according to Maxwell's equations.
        • D. Magnetic and gravitational field: This option is incorrect. A moving electric charge does not generate a gravitational field. The gravitational field is associated with mass, not electric charge.

        Q182. If an electron is accelerated from rest through a potential difference of 100 volts. Its final Kinetic Energy is:

        • A. 1.6 × 10^-18J
        • B. 1.6 × 10^-17J
        • C. 100J
        • D. 100 electron volt

        Explanation: Kinetic Energy = Work done = Q x V = 1.6×10−19×100=1.6×10−17 Joules. This option is correct as seen from the following relation.

        Why the other options are wrong
        • A. This option is incorrect according to the following relation.
        • C. This option is incorrect from the above relation.
        • D. This option is also incorrect as the following formula suggests.

        Q183. The inductance of solenoid depends upon the:

        • A. Area of cross section
        • B. Length of solenoid
        • C. Number of turns
        • D. All of above

        Explanation: Therefore, the correct option is "All of the above" as the inductance of a solenoid depends on the area of cross section, the length of the solenoid, and the number of turns.

        Why the other options are wrong
        • A. Area of cross section: The inductance of a solenoid depends on the area of its cross-section. A larger cross-sectional area allows for more magnetic field lines to pass through, resulting in a higher inductance.
        • B. Length of solenoid: The inductance of a solenoid is directly proportional to its length. A longer solenoid provides a longer path for the magnetic field, resulting in a higher inductance.
        • C. Number of turns: The inductance of a solenoid is directly proportional to the number of turns. More turns create a stronger magnetic field, leading to a higher inductance.

        Q184. The mean value of sinusoidal emf over cycle is:

        • A. Maximum
        • B. Zero
        • C. Maximum and minimum
        • D. No change in emf

        Explanation: Zero: The mean value of a sinusoidal emf over a cycle is zero. This is because the positive and negative values of the sinusoidal wave cancel each other out when averaged over a complete cycle. Therefore, the correct option is "Zero" as the mean value of a sinusoidal emf over a cycle is zero.

        Why the other options are wrong
        • A. Maximum: The mean value of a sinusoidal electromotive force (emf) over a cycle is not the maximum value. The mean value represents the average value of the emf over a complete cycle and is generally not equal to the maximum value.
        • C. Maximum and minimum: The mean value is neither the maximum nor the minimum value of the sinusoidal emf. It is zero, as explained above.
        • D. No change in emf: The mean value does not indicate whether there is a change in the emf. It represents the average value over a cycle, irrespective of any changes that may occur.

        Q185. An efficient voltmeter has:

        • A. Low resistance in comparison to circuit resistance
        • B. High resistance in comparison to circuit resistance
        • C. A resistance equal to circuit resistance
        • D. None of the above

        Explanation: High resistance in comparison to circuit resistance: This is the correct option. An efficient voltmeter should have a high internal resistance compared to the resistance of the circuit. This prevents significant current flow through the voltmeter, ensuring accurate voltage measurement without affecting the circuit's performance. Therefore, the most efficient voltmeter has high resistance compared to the resistance of the circuit it is measuring.

        Why the other options are wrong
        • A. Low resistance in comparison to circuit resistance: An efficient voltmeter should have a high internal resistance compared to the resistance of the circuit it is measuring. This ensures that the voltmeter draws minimal current from the circuit, minimizing the effect on the circuit's voltage and accuracy of measurement.
        • C. A resistance equal to circuit resistance: This option is not ideal. If the voltmeter has the same resistance as the circuit, it will significantly affect the circuit's voltage and accuracy of measurement, leading to inaccurate readings.

        Q186. The period of simple pendulum double when :

        • A. Its length is doubled
        • B. The mass of the bob is double
        • C. Its length is made four time
        • D. The mass and length of the pendulum is made two times

        Explanation: The correct option is C Its length is made four times T = 2π√l/g⇒T∝√l , When length will be four times then,T =√4 =2 According to this relation,

        Why the other options are wrong
        • A. If its length is doubled, the time period will increase but not exactly double of the value.
        • B. It is independent of mass.
        • D. As, explained earlier, the period of pendulum is only determined by its length it is independent of mass.

        Q187. A transformer changes 12V to 18000V and there are 6000 turns in secondary coil. The number of turns in primary coil are:

        • A. 40
        • B. 20
        • C. 30
        • D. 4

        Explanation: 4: If there are 4 turns in the primary coil, the voltage transformation ratio would be 6000/4 = 1500, which matches the given transformation ratio of 12V to 18000V. Therefore, the correct answer is "4" as the number of turns in the primary coil of the transformer is 4.

        Why the other options are wrong
        • A. 40: If there are 40 turns in the primary coil, the voltage transformation ratio would be 6000/40 = 150, which does not match the given transformation ratio of 12V to 18000V.
        • B. 20: If there are 20 turns in the primary coil, the voltage transformation ratio would be 6000/20 = 300, which also does not match the given transformation ratio.
        • C. 30: If there are 30 turns in the primary coil, the voltage transformation ratio would be 6000/30 = 200, which is still not equal to the given ratio.

        Q188. If a person is injured by the shot of gun and all the pellets could not be removed, they may cause poisoning by:

        • A. Hg
        • B. Pb
        • C. Fe
        • D. Sn

        Explanation: Pb (Lead): If pellets containing lead (Pb) remain in the body, they can cause lead poisoning, which can result in neurological, gastrointestinal, and other systemic symptoms.However, it is most dangerous. It's important to note that any foreign object left in the body, regardless of its composition, can lead to complications such as infection, inflammation, or tissue damage. Prompt medical attention is necessary in such cases.

        Why the other options are wrong
        • A. Hg (Mercury): If pellets containing mercury (Hg) remain in the body, they can lead to mercury poisoning, which can affect the nervous system, kidneys, and other organs.
        • C. Fe (Iron): Iron (Fe) pellets are not typically toxic if they remain in the body, as the human body has mechanisms to regulate iron levels. However, if a significant amount of iron is absorbed, it can lead to iron overload and related complications.
        • D. Sn (Tin): Tin (Sn) is not typically toxic to humans, so if pellets containing tin remain in the body, they are unlikely to cause poisoning or significant health issues.

        Q189. In power loss in a capacitor in A.C circuit is:

        • A. P > V°l°
        • B. <P>= V°I° sinθl°
        • C. <P>= V°I° Cos θl
        • D. <P>= zero

        Explanation: In purely inductive or purely capacitive circuit, power loss is zero.

        Why the other options are wrong
        • A. P > V°l°: This statement implies that power loss in a capacitor is greater than the product of voltage and current, which is not accurate. Power loss in a capacitor in an AC circuit is not greater than the product of voltage and current.
        • B. <P> = V°I° sinθl°: This statement represents the true power loss in a capacitor in an AC circuit. It is given by the product of voltage, current, sine of the phase angle (θ), and the length of time (l) for which the power is dissipated.
        • C. <P> = V°I° Cos θl: This statement is incorrect. The correct formula for power loss in a capacitor in an AC circuit involves the sine of the phase angle (θ), not the cosine.

        Q190. The truth table of logic function:

        • A. Summarizes its output
        • B. Tabulates all its input conditions only
        • C. Displays all its input/output possible
        • D. Is not based on the logic algebra

        Explanation: The truth table displays all the input/output possibilities for the logic function. It systematically lists all possible combinations of input values and their resulting output values, allowing for a comprehensive understanding of the function's behavior.

        Why the other options are wrong
        • A. The truth table of a logic function summarizes its output. It presents a tabular representation of all possible combinations of input values and their corresponding output values, providing a concise summary of how the function behaves under different input conditions.
        • B. The truth table does tabulate all its input conditions, but it also includes the output values associated with each input combination. It captures the relationship between inputs and outputs for the logic function.
        • D. The truth table is based on the principles of logic algebra. It provides a systematic and logical representation of how a function behaves based on the input values and their corresponding output values, following the rules of logical operations and truth values.

        Q191. A ball of mass 1g is moving with a velocity of 10³ m/s. The De_Broglie wavelength of the ball is:

        • A. 13.26 × 10^-36 m
        • B. 3.315 × 10-³⁴ m
        • C. 6.63 × 10-³⁴ m
        • D. 4.97 × 10^-26 m

        Explanation: momentum= 1/1000 Kg×1000m/s λ= Ph = 1 6.6×10−34J/s /1=6.6×10 −34mOPTION (A,B and D) are incorrect.As, it is a numerical so it could have only one answer.

        Why the other options are wrong

          Q192. If diamagnetic substance is brought near north or south pole of a bar magnet, it is:

          • A. Attracted by poles
          • B. Attracted by North pole & repelled by south pole
          • C. Attracted by south pole & repelled by North pole
          • D. Repelled by the poles

          Explanation: Diamagnetic substances are those that do not have unpaired electrons in their atoms. When a diamagnetic substance is brought near a magnet, it becomes temporarily magnetized in the opposite direction to the magnet. This causes the diamagnetic substance to experience a weak repulsion from both the north and south poles of the magnet.

          Why the other options are wrong
          • A. "Attracted by poles" is not the correct answer. Diamagnetic substances are repelled, not attracted, by magnetic poles.
          • B. "Attracted by north pole and repelled by south pole" is not the correct answer. Diamagnetic substances are repelled by both the north and south poles of a magnet.
          • C. "Attracted by south pole and repelled by north pole" is also not the correct answer. Diamagnetic substances are repelled by both the north and south poles of a magnet.

          Q193. When an object slides at constant speed down an inclined plane, the coefficient of fraction may be approximately:

          • A. Sin θ
          • B. Cos θ
          • C. Tan θ
          • D. Cot θ

          Explanation: The coefficient of friction is a measure of the frictional force between the object and the surface it is sliding on. It depends on the nature of the surfaces in contact and is typically denoted by the symbol 'μ'. The force of friction is given by the equation: f = μN where f is the force of friction, N is the normal force (the component of the weight of the object that is perpendicular to the inclined surface), and μ is the coefficient of friction.In the case where the object is sliding at constant speed down an inclined plane, the force of friction is equal in magnitude to the component of the weight of the object that is parallel to the plane. This component is given by: mg sin θ θ is the angle of inclination of the plane. Thus, we have: f = mg sin θ Substituting the equation for the force of friction into the equation for the coefficient of friction, we get: μ = f/N = (mg sin θ)/(mg cos θ) = tan θ Therefore, the coefficient of friction is approximately equal to the tangent of the angle of inclination of the plane. So, the correct option is (C) tan theta.

          Why the other options are wrong
          • A. sin theta is incorrect because it gives the value of the component of the weight of the object that is perpendicular to the plane.
          • B. cos theta is also incorrect because it gives the value of the normal force acting on the object.
          • D. cot theta is incorrect because it is the reciprocal of tan theta and does not give the correct value of the coefficient of friction.

          Q194. If the area of a circle is equal to its circumference the radius of this circle is:

          • A. 1
          • B. 2
          • C. 3
          • D. 4

          Explanation: πr2=2πr⟹r=2.The correct option is B. 2. The area of a circle is given by the formula A = πr^2, where r is the radius. The circumference of a circle is given by the formula C = 2πr. If the area of a circle is equal to its circumference, we can set up the equation πr^2 = 2πr. Simplifying this equation, we get r = 2.Therefore, the radius of this circle is 2.AS, IT IS NUMERICALLY DERIVATED SO IT COULD HAVE ONLY ONE ANSWER.

          Why the other options are wrong

            Q195. A ball is just allowed to fall from the window of a moving train, it will hit the ground following a:

            • A. circular path
            • B. hyperbolic path
            • C. straight line path
            • D. parabolic path

            Explanation: This option is correct. When a ball is dropped from a moving train, it follows a parabolic path. The ball moves vertically downward due to the force of gravity, while simultaneously moving horizontally with the train's velocity. The combined effect of these motions results in a parabolic trajectory. The ball's path is curved, but it is not a perfect arc because the horizontal and vertical motions are not independent of each other.

            Why the other options are wrong
            • A. This option is incorrect because when a ball is dropped from a moving train, it does not follow a circular path. A circular path would imply that the ball is continuously changing direction and moving in a curve. However, in this scenario, the ball falls straight down due to the force of gravity acting on it. There is no circular motion involved.
            • B. This option is incorrect as well. A hyperbolic path refers to a trajectory that is shaped like a hyperbola, which is a curve that extends infinitely. When a ball is dropped from a moving train, it falls vertically downwards due to gravity, following a straight line path. There is no curve that resembles a hyperbola.
            • C. This option is also incorrect. Although a ball dropped from a moving train does follow a straight line path vertically downward, it is not the most accurate description. The vertical path of the ball is influenced by both the force of gravity pulling it down and the horizontal motion of the train. As a result, the ball will not hit the ground directly below the window of the moving train, but slightly behind it due to the horizontal motion of the train.

            Q196. A girl sitting on a spinning bus tool with her legs folded , suddenly out spreads then her angular velocity will:

            • A. decrease
            • B. increase
            • C. Remain the same
            • D. first increase and then decrease

            Explanation: The moment of inertia of girl increases (since the mass of her legs is now farther from the axis of rotation). According to the law of conservation of angular momentum, the product of the moment of inertia and the angular velocity must remain constant. If the moment of inertia increases, the angular velocity must decrease in order to keep the total angular momentum constant. So the correct answer is (A) decrease.

            Why the other options are wrong
            • B. is incorrect because the angular velocity cannot increase due to conservation of angular momentum.
            • C. is also incorrect because the angular velocity cannot first increase and then decrease. The total angular momentum must remain constant throughout the motion.
            • D. is incorrect because the moment of inertia has increased, so the angular velocity must decrease to keep the total angular momentum constant.

            Q197. Blue eye colour is recessive to brown eye colour. A brown eyed man whose mother was blue eyed marries a blue-­eyed women. The children will be:

            • A. Both blue eyed and brown eyed 1:1
            • B. All brown eyed
            • C. All blue eyed
            • D. Blue eyed and brown eyed 3:1

            Explanation: The correct option is Both blue-eyed and brown-eyed, 1:1. The man is heterozygous for eye color (Bb), having inherited a blue-eye allele from his mother and a brown-eye allele from his father. The woman is homozygous recessive (bb), with two blue-eye alleles. Their children can inherit either a brown-eye allele or a blue-eye allele from the man and a blue-eye allele from the woman, leading to a 1:1 ratio of brown-eyed (Bb) to blue-eyed (bb) children.The other options are incorrect as they do not reflect the Mendelian inheritance patterns given the genotypes of the parents. All brown-eyed or all blue-eyed children would require different genetic combinations in the parents, and a 3:1 ratio is not possible with a homozygous recessive parent.

            Why the other options are wrong
            • B. This is incorrect because the blue-eyed woman (bb) can only pass on blue-eye alleles. The man, being heterozygous (Bb), can pass on either a brown-eye or blue-eye allele. Therefore, not all children can be brown-eyed.
            • C. This is incorrect because the brown-eyed man is heterozygous (Bb), meaning he can pass on a brown-eye allele, resulting in some children being brown-eyed.
            • D. This ratio is incorrect for this genetic cross. A 3:1 ratio would occur if both parents were heterozygous (Bb), which is not the case here as the woman is homozygous recessive (bb).

            Q198. The allele which is unable to express its effect in the presence of another is called :

            • A. Codominant
            • B. Supplementary
            • C. Complementary
            • D. Recessive

            Explanation: The correct option is d): Recessive.A recessive allele is one that does not express its trait in the phenotype when paired with a dominant allele. The effect of a recessive allele is only observable when an organism has two copies of this allele, making it homozygous recessive. In the presence of a dominant allele, the recessive allele's effect is masked, which is why option d) is correct.Options a), b), and c) do not describe the relationship between alleles where one is masked by another. Codominance (Option a) refers to both alleles being expressed, supplementary (Option b) is not a genetic term for allele interaction, and complementary (Option c) is a term related to DNA base pairing rather than allele interaction.

            Why the other options are wrong
            • A. Codominance occurs when both alleles in a heterozygous individual are fully expressed, resulting in a phenotype that shows both traits equally. Therefore, this is not correct because it does not describe an allele that is unable to express its effect when another allele is present.
            • B. The term 'supplementary' is not standard in genetic contexts for describing allele interactions. It does not describe a scenario where one allele masks another.
            • C. 'Complementary' typically refers to the pairing of DNA bases, not allele interactions. It does not relate to the inability of one allele to express its effect in the presence of another.

            Q199. RR (Red) Antirrhinum is crossed with white (WW) one. Offspring RW are pink. This is an example of

            • A. Dominant-recessive
            • B. Incomplete dominance
            • C. Hybrid
            • D. Supplementary genes

            Explanation: The inheritance pattern observed in the cross between red (RR) and white (WW) Antirrhinum, resulting in pink (RW) offspring, is an example of incomplete dominance. In incomplete dominance, the heterozygous phenotype is an intermediate of the two homozygous phenotypes. This is evidenced by the pink color of the RW offspring, which is a blend of the red and white colors of the parents. In contrast, dominant-recessive inheritance would result in offspring displaying only the dominant phenotype. The term 'hybrid' does not specify the nature of the genetic interaction, and 'supplementary genes' refer to a different genetic interaction not demonstrated in this example.

            Why the other options are wrong
            • A. In dominant-recessive inheritance, one allele completely masks the effect of the other, leading to the dominant phenotype being expressed. This is not the case here, as the offspring is a blend of both parental phenotypes.
            • C. While 'hybrid' refers to the offspring of two different breeds or varieties, it does not describe the specific inheritance pattern observed here.
            • D. Supplementary genes refer to genes that enhance or modify the effect of other genes, not relevant to the blending of phenotypes as seen in this example.

            Q200. A colour blind girl is rare because she will be born only when:

            • A. Her mother and maternal grandfather were colour blind
            • B. Her father and maternal grandfather were colour blind
            • C. Her mother is colour blind and father has normal vision
            • D. Parents have normal vision but grandparents were colour blind

            Explanation: The correct option is B: Her father and maternal grandfather were colour blind. Color blindness is an X-linked recessive disorder, meaning a female must inherit two copies of the recessive allele (Xc) to express the trait. In this scenario, the daughter's father must be colour blind (XcY) to pass on an Xc, and the mother must at least be a carrier (XcX) or colour blind (XcXc) to pass on the second Xc. The maternal grandfather's condition indicates that the mother has at least one Xc, fulfilling the condition.Option A is incorrect because it does not ensure the father passes on an Xc. Option C is incorrect as it lacks information on the father's Xc contribution. Option D is incorrect because normal vision parents are less likely to pass two Xc alleles, despite the grandparents' condition.

            Why the other options are wrong
            • A. If the mother and maternal grandfather were colour blind, the daughter would receive one Xc from her mother. However, she needs another Xc from her father to be colour blind. This option does not guarantee that the father is colour blind, making it incorrect.
            • C. If the mother is colour blind, she will pass on an Xc chromosome. However, for the daughter to be colour blind, she must also receive an Xc from her father. This option does not indicate that the father is a carrier or affected, making it incorrect.
            • D. If both parents have normal vision, it suggests they do not express the colour blindness trait. Both would need to be carriers to pass on the condition to their daughter. Grandparents being colour blind increases carrier likelihood but does not guarantee it, making this option incorrect.

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