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Etea Mdcat 2014 — Solved Past Paper with Answers

All 200 MCQs from Etea Mdcat 2014, 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. 'CHUCKLE‘ mean:

  • A. Bouquet of flowers
  • B. Displeasing manner
  • C. Suppressed laughter
  • D. Religious movement

Explanation: Chuckling is a form of laughter that is done in a quiet manner.

Why the other options are wrong
  • A. A 'bouquet of flowers' refers to an arrangement of flowers, typically given as a gift. It has no connection to the act of laughing.
  • B. A 'displeasing manner' describes behavior that is unpleasant or offensive to others. This is unrelated to laughter or amusement.
  • D. A 'religious movement' is a social movement focused on religious objectives. It does not relate to any form of laughter.

Q2. 'Money Grubbing‘ impllies:

  • A. Money saving
  • B. Money making
  • C. Money hunting
  • D. Money spending

Explanation: Money-grubbing means ‘overeager to make money’."Money hunting" is not a commonly used phrase, and it does not have a standard or widely recognized meaning in the English language. It could potentially be a colloquial term or a unique expression used by a particular group or community, but without further context, it's challenging to determine its specific meaning. If "money hunting" refers to a specific concept or context, please provide more information, and I'll do my best to help you understand its meaning.

Why the other options are wrong
  • A. "Money saving" involves setting aside money rather than spending it. It is about creating a financial reserve for future use, emergencies, or specific goals. This behavior is often associated with prudence and financial planning, not eagerness or greed.
  • B. "Money making" is the process of generating income through various activities like employment, business, or investments. While it involves earning money, it doesn't inherently imply an obsessive or greedy approach.
  • D. "Money spending" refers to using money to buy goods or services. It is a basic financial activity necessary for daily life but does not imply an eager or greedy pursuit of money itself.

Q3. 'Get into a soup‘ impllies:

  • A. Face a predicament
  • B. Play a game of cards
  • C. Swallow a fly in soup
  • D. Go for hot spicy soup

Explanation: Get into a soup’ means to be in an unpleasant or difficult situation.Predicament is a difficult, unpleasant, or embarrassing situation. So option A is correct.

Why the other options are wrong
  • B. Playing a game of cards typically involves leisure and strategy, not difficulty or trouble. Therefore, this option does not align with the idiom 'get into a soup.'
  • C. While this phrase metaphorically suggests an unexpected or undesirable situation, it does not directly relate to the idiom 'get into a soup.' It is more about encountering additional complications rather than a difficult situation itself.
  • D. This option refers to a culinary preference and does not relate to any kind of difficult situation, making it irrelevant to the idiom 'get into a soup.'

Q4. I eagerly look forward _ seeing you again.

  • A. At
  • B. To
  • C. On
  • D. By

Explanation: The question asks you to use correct ​​Adjective + Preposition Combination. The adjective here is ‘forward’ and ‘to’ is always used with forward as a correct preposition. ‘At’ is used after adjectives like ‘employed’, ‘good’ etc. ‘On’ is used after verbs e.g. ‘depend on’. ‘By’ is used after adjectives like ‘composed’, ‘employed’, etc.

Why the other options are wrong
  • A. The preposition "at" is typically used to specify a location, time, or event. It does not correctly pair with the adjective 'forward' in this context.
  • C. The preposition "on" is used for days, dates, and specific surfaces. It does not match the adjective 'forward' in this context.
  • D. The preposition "by" is used to indicate a method or agent, among other uses. It is not used with 'forward' in this context.

Q5. You will be the perfect in charge _ this group.

  • A. Of
  • B. To
  • C. By
  • D. On

Explanation: The correct preposition to use in the given sentence is "of." The sentence would be: "You will be the perfect in charge of this group." In charge of’ means having control of or responsibility for something i.e. the ‘group’ in this case.

Why the other options are wrong
  • B. Incorrect. 'In charge to' is not a standard English phrase. Prepositions like 'in charge of' are fixed expressions.
  • C. Incorrect. 'By' would imply that the group is taking the action, not that someone is responsible for the group.
  • D. Incorrect. 'In charge on' is not a valid collocation in English. Prepositions are often part of fixed expressions.

Q6. 'ARABLE‘ means:

  • A. Not grown since long
  • B. Recently ploughed field
  • C. Watered the night before
  • D. Fit for cultivation

Explanation: Arable refers to land suitable for growing crops.

Why the other options are wrong
  • A. This phrase suggests a state of stagnation or inactivity, which does not relate to the suitability of the land for growing crops.
  • B. While ploughing is a part of preparing land for cultivation, it specifically refers to the act of turning the soil and not necessarily the overall suitability of the land for crop growth.
  • C. This option describes a specific action taken to care for plants, rather than an inherent quality of the land making it suitable for agriculture.

Q7. Choose the correct sentence.

  • A. Does your tram leaw before eight o'clock?
  • B. Does your train leave before eight clock?
  • C. Does your train leave before eight o'clock?
  • D. Do your train leave before eight o'clock?

Explanation: The correct sentence is Option C: "Does your train leave before eight o'clock?" This sentence correctly uses "Does" as the auxiliary verb with the singular subject "your train" to form the present tense question. It also includes the correct spelling of "leave" and "o'clock."Option A is incorrect due to the misspelling of "leaw," which should be "leave." Option B omits "o'clock," making it incomplete in expressing time. Option D uses "Do" incorrectly with the singular subject "train," which requires "Does."

Why the other options are wrong
  • A. The word "leaw" is a misspelling. The correct spelling is "leave." Therefore, the corrected sentence is:"Does your tram leave before eight o'clock?"
  • B. This sentence is missing the word "o'clock" to indicate time correctly. The correct version should be:"Does your train leave before eight o'clock?"
  • D. The auxiliary verb "Do" is incorrect for the singular subject "your train." It should be "Does." The corrected sentence is:"Does your train leave before eight o'clock?"

Q8. A _ child, she was soon bored in class; she already knew more mathematics than her junior school teachers.

  • A. Contemporary
  • B. Lethargic
  • C. Obdurate
  • D. Precocious

Explanation: The correct word to fill in the blank is "precocious."The sentence would be: "A precocious child, she was soon bored in class; she already knew more mathematics than her junior school teachers.""Precocious" means having developed certain abilities or talents at an early age, often beyond what is typical for children of that age. In the given context, it describes a child who is intellectually advanced and shows great maturity and understanding at a young age.Precocious refers to a child having developed certain abilities or inclinations at an earlier age than is usual or expected.

Why the other options are wrong
  • A. Contemporary refers to something occurring in the present or existing at the same time as something else. It does not match the context of intellectual advancement or early development.
  • B. Lethargic means lacking in energy or enthusiasm, which does not fit the context of someone being advanced or knowledgeable at a young age.
  • C. Obdurate means stubborn, which is unrelated to the context of intellectual precocity or being advanced for one's age.

Q9. Sea-fungi is related to:

  • A. Zygomycota
  • B. Ascomycota
  • C. Basidiomycota
  • D. Deuteromycota

Explanation: Sea fungi are related to Basidiomycota.Basidiomycota is a phylum of fungi that includes many well-known groups, such as mushrooms, toadstools, and puffballs. They are often found in various terrestrial habitats, including forests, grasslands, and gardens, but some species can also be found in marine environments, particularly in coastal regions or submerged wood. Sea fungi within the phylum Basidiomycota have adapted to thrive in saltwater and are capable of breaking down and decomposing marine plant material.About 444 species of marine fungi have been described, including 10 species of basidiomycetes, and 360 species of ascomycetes. The remainder of the marine fungi are chytrids and mitosporic or asexual fungi.Reference; Species of Higher Marine Fungi Archived 2013-04-22 at the Wayback Machine University of Mississippi.

Why the other options are wrong
  • A. Zygomycota primarily consists of terrestrial fungi and is not commonly associated with marine environments, making this option incorrect.
  • C. Although Basidiomycota includes some marine fungi, they are far fewer in number compared to Ascomycota, with only about 10 marine species.
  • D. Deuteromycota, often referred to as 'imperfect fungi,' primarily includes asexual fungi and is not predominantly marine. Thus, this option is incorrect.

Q10. Black bread mold is:

  • A. Rhizopus
  • B. Penicillium
  • C. Mucor
  • D. Yeast

Explanation: Black bread mold is Rhizopus.Rhizopus is a common genus of fungi that includes species responsible for causing the black bread mold. It is known for its rapid growth on bread and other food items, especially under warm and humid conditions. The black coloration of the mold is due to its spore-bearing structures, called sporangia, which release black spores as they mature. Rhizopus can spoil food and, in certain cases, may cause infections if the spores are inhaled or come into contact with open wounds.Rhizopus stolonifer is more commonly known as black bread mold. Rhizopus specifically means any rot causing fungi.

Why the other options are wrong
  • B. Penicillium is a genus of fungi known for producing the antibiotic penicillin and is commonly found on decaying fruits and vegetables but not typically associated with black bread mold.
  • C. Mucor is another genus of mold that can appear on food but is generally white or gray, not black, and is not the primary cause of black bread mold.
  • D. Yeast is a type of fungus used in baking and brewing, not typically associated with mold growth on foods like bread.

Q11. Which of the statements about paper chromatography is not correct:

  • A. Paper chromatography is an example of partition chromatography.
  • B. Paper chromatography is most commonly used to separate biologically active substances.
  • C. Paper chromatography can also be applied for separating some inorganic ions.
  • D. Paper chromatography is always used for quantitative analysis.

Explanation: There are limitations to paper chromatography that include;Large quantities of sample cannot be applied on paper chromatography.In quantitative analysis paper chromatography is not effective.Complex mixture cannot be separated by paper chromatography.

Why the other options are wrong
  • A. This statement is true. Paper chromatography involves partitioning components between the stationary and mobile phases. Thus, this option is correct in describing paper chromatography.
  • B. This statement is accurate. Paper chromatography is extensively utilized for separating complex mixtures of biologically active compounds such as amino acids and carbohydrates.
  • C. This statement is correct. Paper chromatography can effectively be used to separate certain inorganic ions.

Q12. Choose the correct option.

  • A. Samar bought an apple, an orange and an pear.
  • B. Samar bought an apple a orange and a pear.
  • C. Samar bought an apple, an orange and a pear.
  • D. Samar bought a apple, an orange and a pear.

Explanation: This option is correct. It correctly uses commas to separate the items in the list ("an apple", "an orange", and "a pear"), and the articles ("an" and "a") are used correctly.

Why the other options are wrong
  • A. This option is incorrect because "an pear" should be corrected to "a pear". The article "an" is used before words that start with a vowel sound, and "pear" starts with a consonant sound, so it should be "a pear".
  • B. This option is incorrect because it does not use commas to separate the items in the list ("an apple", "a orange", and "a pear"). Commas are needed to separate items in a series.
  • D. This option is incorrect because "a apple" should be corrected to "an apple". The article "a" is used before words that start with a consonant sound, and "apple" starts with a vowel sound, so it should be "an apple".

Q13. 'ACQUAINTANCE‘ means a person whom:

  • A. One loves but whom one cannot marry
  • B. One knows but who is not a close friend.
  • C. One can depend on for help in hour of need.
  • D. One can hire for attempting a question paper.

Explanation: An 'acquaintance' means a person whom you know, but not as closely as a friend. They are someone you have met or interacted with, but you might not have a deep or intimate relationship with them.Acquaintance is a noun that refers to a person one knows slightly, but who is not a close friend

Why the other options are wrong
  • A. This option is incorrect because 'acquaintance' does not imply a romantic or deep emotional connection.
  • C. This option is incorrect because 'acquaintance' suggests a more casual relationship, not one of dependence or support in times of need.
  • D. This option is incorrect because it misconstrues the meaning of 'acquaintance' as a professional or transactional relationship, which it is not.

Q14. The committee dissented from the report‘s conclusions. The underlined word means:

  • A. Differed
  • B. Joined
  • C. Deliberated
  • D. Agreed

Explanation: Meanings of the words with explanations:1. Differed: It means to have a disagreement or to be in contrast with something or someone else. When people differ, they have differing opinions, viewpoints, or beliefs about a particular matter.2. Joined: It means to become a member of a group or to come together with others to form a union, team, or association. It can also refer to connecting or attaching things together physically.3. Deliberated: It means to carefully think about or discuss something in a careful and thoughtful manner before making a decision. When people deliberate, they consider different aspects and options before reaching a conclusion.4. Agreed: It means to have a consensus or be in harmony with someone or something. When people agree, they are in accord or have a shared understanding on a particular matter, idea, or opinion.Dissented means disagreement or to differ in opinion. thus option A it is.

Why the other options are wrong
  • B. This option is incorrect. 'Joined' implies becoming part of a group or agreeing to be together, which is the opposite of dissenting.
  • C. This option is incorrect. 'Deliberated' means to carefully think about or discuss something, which does not convey disagreement or differing opinions as dissent does.
  • D. This option is incorrect. 'Agreed' implies a consensus or harmony of opinion, which is contrary to the meaning of dissent.

Q15. 'APPRAISE‘ means:

  • A. Compliment someone publicly
  • B. Describe the plot of a book
  • C. Evaluate the value or quality of something
  • D. Bargain for items in a market

Explanation: "Appraise" means to assess, evaluate, or judge the value, quality, or worth of something or someone. It involves carefully examining the object or person to determine its characteristics, strengths, weaknesses, or potential. Appraising can be done in various contexts, such as appraising the value of a property, appraising an employee's performance, or appraising the quality of a product. It often requires expert knowledge or a critical analysis to provide an informed and accurate appraisal. Appraise means to evaluate or estimate the nature, quality, ability, extent or significance. So the most appropriate option is C.

Why the other options are wrong
  • A. Incorrect. This is a common misconception with the word 'apprise,' which means to inform or notify, but 'appraise' focuses on evaluation rather than giving compliments.
  • B. Incorrect. While storytelling involves describing and narrating, 'appraise' is unrelated to storytelling and focuses on assessing value or quality.
  • D. Incorrect. Bargaining involves negotiating prices, whereas 'appraise' is about evaluating and estimating the value or quality of an item, not purchasing it.

Q16. The senator is opposed _ this new legistation.

  • A. At
  • B. To
  • C. Try
  • D. On

Explanation: We use "to" as a preposition to indicate a destination or direction.

Why the other options are wrong
  • A. This option is incorrect. 'Opposed at' is not a standard construction in English.
  • C. This option is incorrect. 'Try' is not a preposition and does not fit grammatically in this context.
  • D. This option is incorrect. 'Opposed on' is not commonly used in English to indicate opposition to something.

Q17. Add some milk and sugar _ the afternoon tea.

  • A. With
  • B. In
  • C. On
  • D. To

Explanation: Sure, here are sentences using each preposition:1. Use of: The use of smartphones has increased significantly in recent years.2. With: He decorated the cake with colorful icing and sprinkles.3. In: She found her keys in the drawer.4. On: Please place the book on the table.5. To: I'm looking forward to seeing you at the party.Use the preposition 'to' when indicating that there is movement from one place to another.

Why the other options are wrong
  • A. This option suggests accompaniment, which doesn't fit the context of combining ingredients into the tea.
  • B. This option implies that the tea is a container for milk and sugar, which is not the intended meaning here.
  • C. This option indicates placement on a surface, which is incorrect for adding ingredients to a liquid.

Q18. 'Break the ice‘ implies:

  • A. Walk on ice-sheet
  • B. Swallow ice-cube
  • C. Chisel an ice-block
  • D. To initiate conversation

Explanation: "Break the ice" is an idiomatic expression that means to initiate or start a conversation in a social setting with people you don't know well, usually to make them feel more comfortable and open to further communication. It helps to ease tension or awkwardness and create a friendly atmosphere.It basically means to remove the tension at a first meeting , to make a first move and initiate things.

Why the other options are wrong
  • A. This option is incorrect. The phrase does not literally involve walking on ice; it is a metaphorical expression.
  • B. This option is incorrect. Swallowing an ice cube has no relation to the idiomatic meaning of 'break the ice'.
  • C. This option is incorrect. While it involves ice, the phrase is metaphorical and not about physically chiseling ice.

Q19. An 'elegy‘ is a poem written:

  • A. In the memory of a little child
  • B. On the death of someone dear
  • C. On the sighting of an old tutor
  • D. In the love of a dear sweetheart

Explanation: An "elegy" is a poem written to express sorrow, grief, or lamentation, typically in response to the death of a loved one or to reflect on the passing of something significant. It is a form of poetry that is meant to evoke feelings of mourning and remembrance.ELEGY, poem lamenting the death of a public personage or of a friend or loved one; by extension, any reflective lyric on the broader theme of human mortality.

Why the other options are wrong
  • A. This option is incorrect. While an elegy can be written for a child, it is not specifically limited to children; it is a general form for lamenting loss.
  • C. This option is incorrect. Elegies are not traditionally associated with reunions or encounters, but rather with themes of loss and mourning.
  • D. This option is incorrect. While poems about love exist, they are not typically elegies, which are more concerned with themes of death and mourning.

Q20. He was arrested and charged _ murder

  • A. With
  • B. Into
  • C. Over
  • D. About

Explanation: We use "with" to refer to what we use to do something, e.g, They opened the package with a knife.He was arrested and charged with murder.

Why the other options are wrong
  • B. This preposition is typically used to indicate movement or direction and is not appropriate for this context.
  • C. While 'over' can indicate a cause or reason in some contexts, it is not used with 'charged' in legal terms.
  • D. 'About' is used to indicate a topic or subject of discussion and does not fit the legal context of being charged with a crime.

Q21. _ second thought I opted for a cold drink.

  • A. At
  • B. By
  • C. On
  • D. For

Explanation: "On second thought" is used when changing opinion or decision.

Why the other options are wrong
  • A. This option is incorrect. 'At second thought' is not a recognized phrase in English, as 'at' does not convey the sense of revisiting or reconsidering a decision.
  • B. This option is incorrect. 'By second thought' does not fit the context, as 'by' typically indicates a means or method, not a reconsideration.
  • D. This option is incorrect. 'For second thought' is not a standard English expression, as 'for' typically denotes purpose or reason, which does not apply here.

Q22. Both DNA and RNA are synthesize by the process of:

  • A. Transcription
  • B. Replication
  • C. Polymerization
  • D. PCR

Explanation: The process by which DNA is copied to RNA is called transcription.

Why the other options are wrong
  • B. Replication is the process by which DNA makes an identical copy of itself, typically during cell division, not for synthesizing RNA.
  • C. Polymerization refers to the formation of long molecular chains, such as adding nucleotides during DNA replication, but it is not specific to RNA synthesis.
  • D. Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify DNA sequences, not a natural synthesis process for DNA or RNA.

Q23. The cross between two dissimilar individuals is called:

  • A. Test cross
  • B. Interbreeding
  • C. Epistasis
  • D. Hybridization

Explanation: Hybridization is the process of an animal or plant breeding with an individual of another species or variety. So D is the correct option.

Why the other options are wrong
  • A. A test cross involves breeding a homozygous recessive individual with a heterozygote to determine the latter's genotype. It is not specifically about crossing dissimilar individuals but rather about uncovering genetic information.
  • B. Interbreeding typically refers to breeding within the same species, often among closely related individuals, which is opposite to crossing dissimilar individuals.
  • C. Epistasis is a genetic interaction where one gene masks or modifies the expression of another gene. It is about gene interaction rather than the breeding of dissimilar individuals.

Q24. Cell wall of gram-positive bacteria is composed of:

  • A. Glycolipids
  • B. Glycoproteins
  • C. Lipoproteins
  • D. Peptidoglycan

Explanation: Bacterial cell walls are made of peptidoglycan, also called as murein, which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids.

Why the other options are wrong
  • A. Glycolipids are primarily involved in cell membrane composition and are not the main component of bacterial cell walls.
  • B. Glycoproteins are proteins with carbohydrate groups attached, common in eukaryotic cells, but do not form the structural basis of the bacterial cell wall.
  • C. Lipoproteins are more relevant to the outer membrane of gram-negative bacteria rather than the peptidoglycan-rich cell wall of gram-positive bacteria.

Q25. Shade loving plants are called:

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

Explanation: Sciophytes are plants that grow in moderate to low intensity of light under the cover of large trees.

Why the other options are wrong
  • A. Halophytes are plants that thrive in high-salinity environments, such as coastal areas or saline deserts. They are adapted to absorb water with high salt content and are not related to shade conditions.
  • B. Mesophytes are plants that require a moderate amount of water and are typically found in environments that are not extremely dry or wet. They are not specifically adapted to low-light or shaded environments.
  • D. Xerophytes are plants adapted to survive in arid environments with minimal water. They have features like thickened leaves or stems to store water, which are not relevant to shade conditions.

Q26. Any DNA molecule having foreign DNA is called:

  • A. Mutant
  • B. Recombinant
  • C. Crossing over
  • D. All of the above

Explanation: Recombinant DNA is the hybrid DNA made by two or more DNA molecules joined together. So B is the correct option.This technology is used to create new genetic combinations that are then inserted into a host organism, like bacteria, to produce desired traits or products, such as human insulin or genetically modified crops.

Why the other options are wrong
  • A. A mutant refers to an organism or gene that has undergone a mutation, which is a change in the DNA sequence. It does not necessarily involve the introduction of foreign DNA from another organism.
  • C. Crossing over occurs during meiosis when homologous chromosomes exchange genetic material. It is a natural process and does not involve the artificial combination of foreign DNA.
  • D. This option is incorrect because only recombinant DNA involves the integration of foreign DNA from different sources.

Q27. The theory of uniformitarianism was proposed by:

  • A. Hutton and Lyell
  • B. Lamarck
  • C. Georges Cuvier
  • D. Darwin

Explanation: James Hutton along with Charles Lyell developed the concept of uniformitarianism. He believed Earth's landscapes like mountains and oceans formed over a long period of time through gradual processes.

Why the other options are wrong
  • B. Jean-Baptiste Lamarck was a prominent figure in early evolutionary theory, known for his ideas on the inheritance of acquired traits, not geology.
  • C. Georges Cuvier was a key figure in paleontology and advocated for catastrophism, the idea that Earth's history was shaped by sudden, short-lived, violent events.
  • D. Charles Darwin was renowned for his theory of evolution by natural selection, heavily influenced by Lyell's work, but not directly involved in developing uniformitarianism.

Q28. "Photo-phosph-rylation" is:

  • A. ATP synthesis by food energy
  • B. ATP synthesis by solar energy
  • C. ATP synthesis by source of water
  • D. ATP synthesis by source of NADH2

Explanation: It is the process of utilizing light energy to convert ADP to ATP.

Why the other options are wrong
  • A. This describes ATP production through cellular respiration, where energy from food molecules (like glucose) is used, not light energy. Therefore, it doesn't relate to the 'photo' prefix, which refers to light.
  • C. Water provides electrons during photosynthesis but does not directly provide energy for ATP synthesis. The energy for ATP synthesis comes from light, not water.
  • D. NADH2 is an electron carrier involved in energy transfer processes but does not directly drive ATP synthesis in photophosphorylation. It is generated as part of the light-dependent reactions and used later in the Calvin cycle.

Q29. Light absorbing pigments in photosystem I is:

  • A. P 600
  • B. P 680
  • C. P 700
  • D. P 760

Explanation: Photosystem I has chlorophyll a molecule which absorbs maximum light of 700 nm and is called P700, whereas reaction center of photosystem II has P680

Why the other options are wrong
  • A. This option is incorrect. P600 is not a recognized reaction center in photosynthesis.
  • B. This option is incorrect. P680 is the reaction center chlorophyll molecule in Photosystem II, not Photosystem I.
  • D. This option is incorrect. P760 does not correspond to any known photosystem reaction center.

Q30. The enlarged lining epithelium cells connected with groups of developing spermatozoa in testes is:

  • A. Somatic cells
  • B. Sertoli cells
  • C. Stem cells
  • D. Totipotent cells

Explanation: Sertoli cells are the epithelial supporting cells of the seminiferous tubules. They are derived from the epithelial sex cords of the developing gonads.

Why the other options are wrong
  • A. Somatic cells are any cells forming the body of an organism, excluding germ cells, which are involved in reproduction.
  • C. Stem cells are primitive cells with the potential to differentiate into various cell types, but they do not directly support spermatozoa in the testes.
  • D. Totipotent cells are capable of developing into a complete organism or differentiating into any cell type, but are not involved in the support of spermatozoa development in the testes.

Q31. The hormone released by the posterior pitultary that stimulates the contraction of uterine and mammary gland muscles is called:

  • A. Prolactin
  • B. LH (Luteinizing Hormone)
  • C. FSH (Follicle-Stimulating Hormone)
  • D. Oxytocin

Explanation: Oxytocin is the hormone released by the posterior pituitary that stimulates the contraction of uterine(during labor) and mammary gland muscles.

Why the other options are wrong
  • A. Prolactin is a hormone released by the anterior pituitary gland, not the posterior pituitary. It is involved in milk production and breast tissue development, but does not stimulate muscle contractions.
  • B. Luteinizing Hormone (LH) is released by the anterior pituitary and mainly regulates processes in the reproductive system such as ovulation, but it is not involved in uterine or mammary gland muscle contractions.
  • C. Follicle-Stimulating Hormone (FSH) is also released by the anterior pituitary and is important for the growth of ovarian follicles, not for muscle contractions in the uterus or mammary glands.

Q32. A study of communities in relation to environment is called:

  • A. Social ecology
  • B. Synecology
  • C. Autoecology
  • D. Heteroecology

Explanation: Synecology (or community ecology) refers to the study of groups of organisms in relation to their environment.

Why the other options are wrong
  • A. Social ecology examines the interactions between human societies and their environments, focusing predominantly on social and environmental issues.
  • C. Autoecology is the study of individual species in relation to their environment, focusing on their behavior, physiology, and interactions with the abiotic factors.
  • D. Heteroecology is not a recognized branch of ecology. The term does not correspond to any established ecological study.

Q33. In Eukaryotes, DNA replication proceeds at the rate of:

  • A. 50 base pairs per second
  • B. 40 base pairs per second
  • C. 20 base pairs per second
  • D. 30 base pairs per second

Explanation: Eukaryotic DNA replication typically occurs at a rate of approximately 50 base pairs per second. This rate reflects the complex nature of eukaryotic cells, which have larger genomes and more intricate regulatory mechanisms than prokaryotic cells. The process is meticulously controlled to ensure accuracy, with proofreading and repair mechanisms in place. The other options, 40, 30, and 20 base pairs per second, underestimate the replication capability of eukaryotic cells, highlighting a lack of alignment with the generally accepted data on replication speeds in these organisms.

Why the other options are wrong
  • B. Although slightly close, 40 base pairs per second is below the recognized average and does not account for the efficiency usually observed in eukaryotic DNA replication.
  • C. This rate is significantly slower than the actual rate, indicating a misunderstanding of the replication process's efficiency in eukaryotic cells.
  • D. While closer to the correct rate than 20, it still underestimates the efficiency of eukaryotic DNA replication processes.

Q34. Fatty acids are:

  • A. Unsaturated dicarboxylic acid
  • B. Long chain alkanoic acid
  • C. Aromatic carboxylic acid
  • D. Aromatic dicarboxylic acid

Explanation: Alkanoic acids are alkane-derived organic compounds that contain the carboxylate (-COOH) functional group and fatty acids are carboxylic acids with long hydrocarbon chains.

Why the other options are wrong
  • A. Unsaturated dicarboxylic acids contain two carboxyl groups (-COOH) and have unsaturation within the chain, which differentiates them from typical fatty acids. Fatty acids generally contain a single carboxyl group and are not primarily characterized by unsaturation within the context of dicarboxylic acids. Thus, this is an incorrect option.
  • C. Aromatic carboxylic acids have a carboxyl group attached to an aromatic ring structure. They do not typically feature the long hydrocarbon chains that define fatty acids. Therefore, this is an incorrect option.
  • D. Aromatic dicarboxylic acids contain two carboxyl groups attached to an aromatic ring. These structures differ significantly from fatty acids, which have long hydrocarbon chains. Thus, this is an incorrect option.

Q35. Saponification of a fat:

  • A. Always results in the formation of soaps.
  • B. Results in the formation of esters.
  • C. Results in the formation of waxes.
  • D. Results in the formation of glycerol and soap.

Explanation: Saponification is a chemical process where fats or oils react with an alkali, such as sodium hydroxide (NaOH) or potassium hydroxide (KOH), resulting in the formation of glycerol and soap. The soap consists of the salts of fatty acids, which are the main products of interest. Option A accurately describes this outcome, while the other options incorrectly associate saponification with ester or wax formation. Option D is technically correct but doesn't highlight the primary goal of the process, which is soap production.

Why the other options are wrong
  • B. Esters are produced by the reaction of an organic acid with an alcohol, not through saponification.
  • C. Waxes are not produced through saponification; they are formed by the esterification of long-chain alcohols with fatty acids.
  • D. While technically correct, this option is less precise because it doesn't emphasize that soaps are the primary product of interest in saponification.

Q36. Carbylamine test is given by:

  • A. Primary amines
  • B. Secondary amines
  • C. Tertiary amines
  • D. All of these

Explanation: Only primary amines give the carbylamine test. Hoffmann's carbylamine test/ Isocyanide test:Aliphatic or aromatic primary amines on heating with chloroform and alcoholic KOH give foul smelling alkyl isocyanides or carbylamines. This test is not given by secondary or tertiary amines.

Why the other options are wrong
  • B. Secondary amines do not have a hydrogen on the nitrogen that can be replaced by the isocyanide group, so they do not give the carbylamine test.
  • C. Tertiary amines also lack the necessary hydrogen on the nitrogen for the carbylamine reaction, and hence do not produce isocyanides.
  • D. This option is incorrect as only primary amines give the carbylamine test, not secondary or tertiary amines.

Q37. From the following, which one particle belongs to lepton group:

  • A. Neutrinos
  • B. Protons
  • C. Neutrons
  • D. Mesons

Explanation: Neutrinos are subatomic particles that belong to the family of elementary particles known as leptons. They are among the most abundant particles in the universe and play a crucial role in various astrophysical and particle physics phenomena.Key characteristics of neutrinos include:1. Electrically neutral: Neutrinos have no electric charge, which means they do not interact with electromagnetic forces. They are only influenced by weak nuclear forces and gravity.2. Very low mass: Neutrinos have extremely low mass compared to other elementary particles. While their exact masses are not yet precisely determined, they are much lighter than electrons and other charged particles.3. Nearly massless and relativistic: Neutrinos are known to travel very close to the speed of light, which makes them nearly massless and relativistic.4. Three types (flavors): There are three known types or flavors of neutrinos: electron neutrinos (νe), muon neutrinos (νμ), and tau neutrinos (ντ). Each type is associated with a specific charged lepton (electron, muon, and tau, respectively).5. Oscillation: Neutrinos can undergo a phenomenon called neutrino oscillation, where they can change from one flavor to another as they travel through space. This discovery proved that neutrinos have mass and provided insight into the fundamental properties of these elusive particles.Neutrinos are produced in various astrophysical processes, such as nuclear reactions in the Sun and other stars, supernovae explosions, and cosmic ray interactions. They can travel vast distances through space without much interaction with matter, making them challenging to detect.Neutrino detectors are specially designed to capture and study neutrinos. They use large volumes of materials, such as water or liquid argon, to detect the very rare interactions of neutrinos with other particles. Neutrino research provides valuable insights into the fundamental nature of matter, the early universe, and astrophysical phenomena that involve high-energy processes.Lepton is an elementary particle of half-integer spin (spin 1⁄2) that does not undergo strong interactions .There are six leptons in the present structure, the electron, muon, and tau particles and their associated neutrinos.The rest are Hadrons. Hadron is a subatomic particle of a type including the baryons and mesons, which can take part in the strong interaction.

Why the other options are wrong
  • B. Protons are not leptons; they are baryons, which are a type of hadron. Protons are composed of three quarks and participate in strong nuclear interactions.
  • C. Neutrons, like protons, are baryons and are made up of three quarks. They are not leptons and also participate in strong nuclear interactions.
  • D. Mesons are hadrons consisting of a quark-antiquark pair. They are not part of the lepton group and participate in strong nuclear interactions.

Q38. Which of the following is an enzyme lacking disease?

  • A. PKU
  • B. Alkaptonuria
  • C. Anuria
  • D. Dluria

Explanation: Phenylketonuria (PKU) is the correct answer as it is a genetic disorder caused by a deficiency of the enzyme phenylalanine hydroxylase (PAH). This enzyme is critical for the metabolism of the amino acid phenylalanine. Without this enzyme, phenylalanine accumulates and can lead to neurological damage. Alkaptonuria also involves an enzyme deficiency, but it is not the enzyme referenced in the question, and anuria and dluria are unrelated to enzyme deficiencies.

Why the other options are wrong
  • B. Alkaptonuria is a rare inherited disorder in which the body cannot fully break down the amino acids tyrosine and phenylalanine due to a deficiency of the enzyme homogentisate 1,2-dioxygenase. Although it involves an enzyme deficiency, it is not the focus of this question.
  • C. Anuria is a condition characterized by the kidneys' failure to produce urine. It is not related to enzyme deficiencies but rather to kidney function.
  • D. Dluria is not a recognized medical condition and is likely included as a distractor.

Q39. Which of the following play role in Biorhythm?

  • A. MSH
  • B. LH
  • C. ADH
  • D. Melatonin

Explanation: Melatonin is a hormone involved in many biological and physiological regulations in the body. It is an effective hormone for human biorhythm (circadian rhythm) as the main role of this hormone is to maintain the biological clock and to adjust the body rhythm.

Why the other options are wrong
  • A. Melanocyte-stimulating hormone (MSH) is involved in skin pigmentation and appetite control but does not directly influence biorhythms.
  • B. Luteinizing hormone (LH) plays a critical role in the reproductive system, particularly in triggering ovulation, but it does not regulate biorhythms.
  • C. Antidiuretic hormone (ADH) helps regulate water balance in the body by controlling the concentration of urine, rather than influencing biorhythms.

Q40. Hypothalamus is a part of:

  • A. Diencephalon
  • B. Myelencephalon
  • C. Telencephalon
  • D. Metencephalon

Explanation: The hypothalamus is a region of the forebrain located below the thalamus, forming the basal portion of the diencephalon.

Why the other options are wrong
  • B. The myelencephalon is not associated with the hypothalamus. It primarily includes the medulla oblongata, which is part of the brainstem, responsible for autonomic functions. Thus, this option is incorrect.
  • C. The telencephalon refers to the cerebral hemispheres, the most developed part of the forebrain, responsible for higher cognitive functions. It does not include the hypothalamus, making this option incorrect.
  • D. The metencephalon is a portion of the hindbrain that develops into the pons and cerebellum, which are involved in motor control and balance. Since the hypothalamus is not part of the metencephalon, this option is incorrect.

Q41. Blue green algae, besides chlorophyll also possess another pigment known as:

  • A. Phycocyanin
  • B. Phycoerythrin
  • C. Phycobillirubin
  • D. Phycobilliprotein

Explanation: The microbes also contain the same chlorophyll a compound used by plants. Some blue-green algae possess a different photosynthetic pigment, which is known as phycoerythrin.

Why the other options are wrong
  • A. Phycocyanin is a blue pigment found in cyanobacteria, but it is not the pigment being asked about in this question. It primarily absorbs orange and red light and contributes to the blue-green color of cyanobacteria.
  • C. Phycobillirubin is not a recognized pigment in photosynthetic organisms, making this option incorrect.
  • D. Phycobiliproteins are a group of water-soluble proteins that include pigments such as phycocyanin and phycoerythrin. While phycoerythrin is a type of phycobiliprotein, the question is specifically asking for a pigment name, making this option too broad.

Q42. Incomplete double circulation is found in:

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

Explanation: Amphibians have a three-chambered heart comprising two atria and one ventricle. Oxygenated and deoxygenated blood received in the left and right atrium, respectively, gets mixed in the single ventricle, hence it is termed as incomplete double circulation.

Why the other options are wrong
  • A. Aves, or birds, have a highly efficient circulatory system with a 4-chambered heart. This structure allows for complete separation of oxygenated and deoxygenated blood, resulting in complete double circulation.
  • B. Fishes possess a single circulatory system with a 2-chambered heart. Blood flows in a single loop: heart to gills, gills to body, and back to heart, which is not a double circulation.
  • D. Mammals have a 4-chambered heart with complete separation of oxygenated and deoxygenated blood, enabling complete double circulation.

Q43. Which of the following animal is included in protostome?

  • A. Sea horse
  • B. Sea mouse
  • C. Sea cucumber
  • D. Sea lion

Explanation: Annelids, Molluscs, and arthropods fall into the category of protostomes. Sea mice belong to the phylum annelida, therefore they are protostomes.Sea lions, and sea horses are chordates, whereas sea cucumbers are echinoderms.Protostomes are organisms in which blastopore develops into the mouth. These include phylums Annelida, Arthropoda, Mollusca.Deuterostomes are organisms in which blastopore develops into anus first and later into mouth. These include phylums Echinodermata, Hemichordate, Chordata.

Why the other options are wrong
  • A. Sea horses belong to the class Osteichthyes of superclass Pisces (fish) in the phylum Chordata, which are deuterostomes. Deuterostomes develop the anus before the mouth during embryonic development.
  • C. Sea cucumbers are echinoderms, belonging to the phylum Echinodermata, and are deuterostomes. Deuterostomes develop the anus first and then the mouth.
  • D. Sea lions are mammals in the phylum Chordata, which are deuterostomes. As with other chordates, they develop the anus before the mouth during embryonic development.

Q44. How many waling legs are present in arachnids?

  • A. 4
  • B. 6
  • C. 8
  • D. 10

Explanation: Arachnids(spider-like) is a class of Phylum Arthropoda with 4 pairs of legs, so a total of 8 legs.

Why the other options are wrong
  • A. This option is incorrect. Arachnids have more than two pairs of walking legs.
  • B. This option is incorrect. While insects have 6 legs, arachnids have more.
  • D. This option is incorrect. Arachnids do not have 5 pairs of legs.

Q45. In octopus, the foot is modified into:

  • A. Disc
  • B. Arm
  • C. Foot
  • D. Siphon

Explanation: The muscular foot has been modified in cephalopods (Octopus) to form the tentacles and the siphon.The siphon is the tubular portion of the octopus that can draw water in and out of its body using its muscular mantle. This action allows oxygenated water to flow over its internal gills so that it can breathe.

Why the other options are wrong
  • A. This option is incorrect. The term 'disc' does not describe any known modification of the octopus's foot.
  • B. This option is incorrect. While the arms of an octopus are remarkable, they are not a direct modification of the foot.
  • C. This option is incorrect. The term 'foot' refers to the original form in mollusks, not its modification in octopuses.

Q46. Which of the following is included in deuterestome?

  • A. Brittle star
  • B. Scorpion
  • C. Chaetopterus
  • D. Unio

Explanation: Brittle Stars are Echinoderms which are marine animals having radial symmetry with five parts, often with spines. So it is a deuterostome. Deuterostomia are animals typically characterized by their anus forming before their mouth during embryonic development.

Why the other options are wrong
  • B. Scorpions are arthropods, belonging to the class Arachnida. Arthropods are protostomes, meaning their mouth forms before the anus during embryonic development.
  • C. Chaetopterus, commonly known as the parchment worm, is an annelid in the class Polychaeta. Annelids are protostomes, characterized by their segmented bodies.
  • D. Unio is a genus of freshwater mussels in the class Bivalvia, phylum Mollusca. Mollusks are protostomes, known for their soft bodies and, in many cases, calcareous shells.

Q47. Murein cell-wall is composed of:

  • A. Sugar and amino acids
  • B. Calcium pectate
  • C. Glycoprotein
  • D. Peptidoglycan

Explanation: Bacterial cell walls are made of peptidoglycan, also called as murein, which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids.

Why the other options are wrong
  • A. This option is misleading as it describes components found in various biological structures, but not specifically the murein cell wall.
  • B. Calcium pectate is a component of plant cell walls, not bacterial cell walls.
  • C. Glycoproteins are found on cell membranes and are not a structural component of bacterial cell walls.

Q48. The genome of the most animals and higher plants is:

  • A. DNA
  • B. RNA
  • C. Both DNA and RNA
  • D. Either DNA or RNA

Explanation: Plant genome assembly represents the complete genomic sequence of a plant species, which is assembled into chromosomes and other organelles by using DNA (deoxyribonucleic acid) fragments that are obtained from different types of sequencing technology.

Why the other options are wrong
  • B. RNA is not the primary genetic material in most organisms' cells. It plays a crucial role in protein synthesis and other cellular processes but does not serve as the main hereditary material in animals and higher plants.
  • C. While both DNA and RNA are present in cells, DNA is the molecule that constitutes the genome of animals and higher plants, not both together.
  • D. This is incorrect. The genome of animals and higher plants is composed of DNA, not RNA, nor can it be either one arbitrarily.

Q49. Which statement is wrong about the fourth state of matter known as plasma?

  • A. The plasma contains an equal amount of positive and negative charges and is almost neutral as a whole.
  • B. Plasma exists in the atmosphere of stars.
  • C. Plasma exists in the region around the sun.
  • D. There is less matter in the plasma state than in the solid, liquid, and gaseous states.

Explanation: Plasma is the highest energy state of matter. It consists of a collection of free-moving electrons, positive ions and neutral particles.

Why the other options are wrong
  • A. Plasma is electrically neutral overall because the number of negatively charged electrons equals the number of positively charged ions.
  • B. Stars like our Sun are composed of ionized gas known as plasma. Due to the high temperatures, atoms are nearly completely ionized into ions, forming plasma.
  • C. The region around the Sun, including the solar corona and solar wind, consists of plasma. The high-energy environment causes atoms to ionize.

Q50. Deficiency of which of the following causes diuresis?

  • A. LH (Luteinizing Hormone)
  • B. ACTH (Adrenocorticotropic Hormone)
  • C. FSH (Follicle-Stimulating Hormone)
  • D. ADH (Antidiuretic Hormone)

Explanation: Antidiuretic hormone (ADH) is a chemical produced in the brain that causes the kidneys to release less water, decreasing the amount of urine produced. A high ADH level causes the body to produce less urine. A deficiency results in greater urine production.ADH (Antidiuretic Hormone), also known as vasopressin, is a hormone produced by the hypothalamus and released by the posterior pituitary gland. Its primary role is to regulate the water balance in the body by controlling the amount of water reabsorbed by the kidneys. ADH plays a crucial role in maintaining proper hydration and preventing excessive water loss.The main functions of ADH in the kidneys are as follows:1. Water reabsorption: When the body is dehydrated or when the blood osmolarity (concentration of solutes) increases, the hypothalamus senses this change and signals the posterior pituitary to release ADH into the bloodstream. ADH then acts on the kidney's collecting ducts, making them more permeable to water. As a result, water is reabsorbed from the filtrate back into the bloodstream, reducing the amount of water lost in the urine.2. Concentration of urine: By increasing water reabsorption, ADH helps in concentrating urine. When the body is dehydrated, ADH levels rise, and more water is reabsorbed from the urine, leading to a reduced volume of urine with a higher concentration of waste products.3. Regulation of blood pressure: In addition to its role in water balance, ADH also has vasoconstrictive effects, meaning it can constrict blood vessels. This property helps maintain blood pressure by narrowing blood vessels and increasing vascular resistance.Imbalances in ADH levels can lead to various medical conditions. For example:1. Diabetes Insipidus: In diabetes insipidus, the body either fails to produce enough ADH (central diabetes insipidus) or the kidneys do not respond appropriately to ADH (nephrogenic diabetes insipidus). As a result, excessive amounts of dilute urine are produced, leading to increased thirst and frequent urination.2. Syndrome of Inappropriate ADH (SIADH): In SIADH, the body releases excessive amounts of ADH, leading to water retention and a decreased concentration of sodium in the blood. This can result in hyponatremia (low blood sodium levels) and fluid overload.The regulation of ADH release is tightly controlled by the body's homeostatic mechanisms, ensuring that water balance is maintained within a narrow range. ADH is a critical hormone in the body's overall water balance and helps to ensure that the body remains properly hydrated and the blood osmolarity remains within a healthy range.

Why the other options are wrong
  • A. Incorrect. Luteinizing Hormone (LH) is primarily involved in regulating reproductive functions, such as ovulation and testosterone production. It does not play a role in water balance or urine production.
  • B. Incorrect. Adrenocorticotropic Hormone (ACTH) stimulates the adrenal glands to produce cortisol and other hormones, but it does not directly influence diuresis or water retention.
  • C. Incorrect. Follicle-Stimulating Hormone (FSH) is involved in the maturation of reproductive cells and has no direct impact on urine production or water balance.

Q51. In angiosperms the megaspore develops into:

  • A. Embryo-Sac
  • B. Embryo
  • C. Seed
  • D. Male gametophyte

Explanation: The functional megaspore grows into an Embryo sac in angiosperms.

Why the other options are wrong
  • B. The embryo is formed after fertilization, not directly from the megaspore. It results from the fusion of male and female gametes within the embryo sac.
  • C. The seed is the mature ovule after fertilization, containing the embryo and endosperm. It is not directly developed from the megaspore.
  • D. The male gametophyte is formed from pollen grains and is not related to the development of the megaspore, which forms the female gametophyte or embryo sac.

Q52. All of the following plants posses hermaphrodite flowers except:

  • A. Lathyrus odoratus
  • B. Solanum nigrum
  • C. Zea mays
  • D. Avena sativa

Explanation: Zea-Mays (corn) are a monoecious plant, a hermaphrodite, where both the male and female reproductive parts are present in the same plant.

Why the other options are wrong
  • A. Lathyrus odoratus, commonly known as sweet pea, belongs to the Fabaceae family and possesses hermaphroditic flowers, meaning each flower contains both male and female reproductive organs.
  • B. Solanum nigrum, or black nightshade, is part of the Solanaceae family and also has hermaphroditic flowers, with both male and female reproductive structures present in the same flower.
  • D. Avena sativa, or oat, is also a member of the Poaceae family. Unlike corn, it has hermaphroditic flowers containing both male and female organs.

Q53. Choose the correct relation about the percent yield. It is equal to:

  • A. The ratio of actual yield to theoretical yield multiplied by 100
  • B. The difference between theoretical yield and actual yield
  • C. The ratio of theoretical yield to actual yield multiplied by 100
  • D. The actual yield divided by 100

Explanation: The percent yield equation is:percent yield = actual yield / theoretical yield x 100%The percent yield is the ratio of the actual yield over the theoretical yield multiplied by 100.The actual yield is the quantity of a product that is obtained from a chemical reaction. In contrast, the calculated or theoretical yield is the amount of product that could be obtained from a reaction if all of the reactant converts to product.

Why the other options are wrong
  • B. This option is incorrect because it describes how to find the yield difference, not the percent yield. Percent yield is a ratio, not a difference.
  • C. This is incorrect as it inverts the relationship. Percent yield is the actual over theoretical, not the other way around.
  • D. This option is incorrect because it doesn't consider the theoretical yield, which is essential for calculating percent yield.

Q54. Accessory pigments are:

  • A. Red-Yellow-Green
  • B. Red-Orange-Blue
  • C. Orange-Blue-Green
  • D. Red-Orange-Yellow

Explanation: Accessory Pigments are the source of much of the RED-ORANGE-YELLOW coloration that we see in plant leaves.

Why the other options are wrong
  • A. While red and yellow are associated with carotenoids, green is a color more typical of chlorophyll, which is considered a primary pigment, not an accessory pigment.
  • B. Blue is not a common color for accessory pigments in land plants and algae. Carotenoids, which are accessory pigments, are usually red, orange, or yellow.
  • C. While orange is associated with carotenoids, blue and green are not typical colors for accessory pigments in plants. Green is related to chlorophyll, and blue is more associated with phycobilins in certain algae and cyanobacteria.

Q55. Chemiosmosis occurs in the:

  • A. Grana
  • B. Stroma
  • C. Thylakoids
  • D. Intergrana

Explanation: In chloroplasts, chemiosmosis occurs in the thylakoids.

Why the other options are wrong
  • A. Incorrect. Grana are stacks of thylakoids, but chemiosmosis specifically occurs across the thylakoid membrane, not the entire grana.
  • B. Incorrect. The stroma is the fluid-filled space surrounding the thylakoids where the Calvin cycle occurs, not chemiosmosis.
  • D. Incorrect. Intergrana are the connecting lamellae between grana, aiding in structural support, and do not directly participate in chemiosmosis.

Q56. If two heterozygous tall plants are crossed together, the proportion of phenotypically tall plants will be:

  • A. 50%
  • B. 25%
  • C. 75%
  • D. 100%

Explanation: A cross between two heterozygous tall plants results in 25% homozygous tall, 50% heterozygous tall, and 25% dwarf plants. So we add 50+25 to get 75% as the proportion of phenotypically tall plants.

Why the other options are wrong
  • A. This option is incorrect. A 50% ratio would imply equal numbers of tall and short phenotypes, which is not the case here.
  • B. This option is incorrect. A 25% ratio would occur if all offspring were homozygous recessive, resulting in short plants only, which is not applicable in this cross.
  • D. This option is incorrect. A 100% ratio would mean all offspring are tall, which would only happen if both parents were homozygous tall (TT), not heterozygous (Tt).

Q57. A spore of Fern plant develops into:

  • A. Zygote
  • B. Sporophyte
  • C. Gametophyte
  • D. Prothalus

Explanation: Released spores grow into a gametophyte which is a very small heart shaped structure.

Why the other options are wrong
  • A. A zygote is the result of fertilization between sperm and egg cells, not the direct development from a spore.
  • B. The sporophyte is the mature fern plant that produces spores, not what a spore directly develops into.
  • D. 'Prothalus' is a misspelling of 'prothallus,' which is another term for the gametophyte stage.

Q58. The oxygen carrying capacity of haemoglobin in humans when the blood is 100% oxygenated is:

  • A. 19.4 ml
  • B. 19.6 ml
  • C. 20 ml
  • D. 21 ml

Explanation: In 100 ml of blood, there is about 15 g of hemoglobin, which can bind approximately 20.1 ml of oxygen. This value is considered the oxygen binding capacity of blood (Cb). The correct answer is 20 ml because it reflects the typical carrying capacity when hemoglobin is fully saturated with oxygen. Options 19.4 ml and 19.6 ml are slightly lower than the actual capacity, while 21 ml exceeds the normal capacity for hemoglobin in fully oxygenated blood.

Why the other options are wrong
  • A. This value is slightly below the typical carrying capacity of hemoglobin when fully saturated with oxygen.
  • B. This is still below the expected capacity for fully saturated hemoglobin in blood.
  • D. This value exceeds the typical oxygen carrying capacity of hemoglobin in fully saturated blood.

Q59. Which of the following fish have 14 pairs of gill slits?

  • A. Dogfish
  • B. Lamprey
  • C. Catfish
  • D. Ray fish

Explanation: Maximum number of gill slits present in cyclostomes . Cyclostomes have 6-15 pairs of gills. Lampreys are example of cyclostomes.

Why the other options are wrong
  • A. Incorrect. Dogfish, a type of shark included in the class Chondrichthyes, usually have five pairs of gill slits. They do not have fourteen pairs.
  • C. Incorrect. Catfish belong to the class Actinopterygii and have a single pair of gill openings covered by an operculum, not 14 pairs.
  • D. Incorrect. Rays, like sharks, are cartilaginous fish and typically have five to seven pairs of gill slits, not fourteen.

Q60. Liquid crystalline substances are used to locate tumors in the body because:

  • A. These parts of the body are warmer than the surroundings
  • B. These parts of the body are cooler than the surroundings
  • C. These parts of the body are constantly increasing and decreasing with the temperature
  • D. None of the above options are correct

Explanation: Liquid crystalline substances are used to locate the viens, arteries, infections, and tumors. The reason is that these parts of the body are warmer than the surrounding tissues.

Why the other options are wrong
  • B. These parts of the body are not cooler than the surroundings. Instead they are warmer than the surroundings. So, it is an incorrect option.
  • C. It is an incorrect option as these parts of the body are warmer than the surrounding and the temperature does not increase or decrease constantly.
  • D. Option A is correct, so this option is incorrect.

Q61. In which of the following, does the pharynx opens directly into the intestine?

  • A. Planaria
  • B. Earthworm
  • C. Cockroach
  • D. Snail

Explanation: In planaria, the mouth opens into muscular tubular pharynx which leads into the intestine.

Why the other options are wrong
  • B. Earthworms have a complex digestive system that includes a pharynx, esophagus, crop, gizzard, and intestine. The pharynx opens into the esophagus, not directly to the intestine.
  • C. Cockroaches have a digestive system with multiple components: pharynx, esophagus, crop, gizzard, and midgut. The pharynx leads to the esophagus, not directly to the intestine.
  • D. Snails have a digestive system where the pharynx leads to the esophagus, followed by the stomach, and then the intestine. The connection is not directly from the pharynx to the intestine.

Q62. Bile is released from the gall bladder by the action of:

  • A. Gastrin
  • B. Cholecystokinin
  • C. Secretin
  • D. Renin

Explanation: When stimulated by the cholecystokinin (CCK), the gallbladder contracts pushing bile through the cystic duct and into the common bile duct.

Why the other options are wrong
  • A. Gastrin is a hormone that mainly stimulates the secretion of gastric acid by the stomach and has no direct role in the release of bile from the gallbladder.
  • C. Secretin is a hormone that primarily stimulates the pancreas to release bicarbonate to neutralize acid in the duodenum. It does not directly cause the release of bile from the gallbladder.
  • D. Renin is an enzyme involved in blood pressure regulation and electrolyte balance, not in the digestive process or bile release.

Q63. To decrease the salt potential, the guard cells absorb:

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

Explanation: Influx of potassium ions decreases water potential in the guard cell so water enters the cell from surrounding cells. As a result salt potential decreases.

Why the other options are wrong
  • A. Incorrect. Sodium ions are not primarily involved in the osmotic regulation of guard cells and can be detrimental to plants in high concentrations.
  • B. Incorrect. Magnesium is essential for chlorophyll production and enzyme function but does not majorly influence osmotic balance in guard cells.
  • D. Incorrect. Calcium ions are crucial in signaling processes within plant cells but not directly involved in osmotic adjustments needed for stomatal movement.

Q64. The product of light dependent reactions are:

  • A. RuBP + ATP
  • B. RuBP + PGAL
  • C. NADPH + ATP
  • D. PGAL + ATP

Explanation: The two products of light dependent reaction of photosystem are ATP and NADPH.The light reaction is the first stage of the photosynthesis process in which solar energy is converted into chemical energy in the form of ATP and NADPH. The three products of the light reaction of photosynthesis are ATP, NADPH, and O2.

Why the other options are wrong
  • A. RuBP (Ribulose-1,5-bisphosphate) is involved in the Calvin cycle, not directly produced in the light-dependent reactions. ATP is a product of the light-dependent reactions, but it does not pair with RuBP as a direct output.
  • B. Both RuBP and PGAL (Glyceraldehyde-3-phosphate) are associated with the Calvin cycle, which follows the light-dependent reactions. Neither is directly produced by the light-dependent reactions.
  • D. While ATP is generated during the light-dependent reactions, PGAL is not. PGAL is a product of the Calvin cycle, which utilizes ATP and NADPH produced in the light-dependent reactions.

Q65. All of the following are gametophytes except:

  • A. Club Mosses
  • B. Funaria
  • C. Liver-Worts
  • D. Horn-Worts

Explanation: In Club mosses also called lycopsids, the gametophyte is mainly underground.

Why the other options are wrong
  • B. Funaria, a type of moss, has a dominant gametophyte phase, which is the main visible part of the plant.
  • C. Liverworts have a gametophyte-dominant life cycle, meaning the gametophyte is the main phase of the plant.
  • D. Hornworts also exhibit a gametophyte-dominant life cycle, where the gametophyte is the main phase of the plant.

Q66. All of the following are dioecious except:

  • A. Ulva
  • B. Funaria
  • C. Marchantia
  • D. Polytrichum

Explanation: Funaria (cord moss) is a bryophyte. Funaria is monoecious and autoecious i.e., male and female reproductive structures develop on different branches of the same plant.

Why the other options are wrong
  • A. Ulva (sea lettuce) is a chlorophyte and is typically dioecious, meaning it has separate male and female individuals for reproduction.
  • C. Marchantia is a liverwort, which is part of the bryophyte group, and is strictly dioecious, having separate male and female plants.
  • D. Polytrichum (common haircap moss) is a bryophyte that is dioecious, with separate male and female plants.

Q67. Coelentrates have hydrostatic skeletion except:

  • A. Coral
  • B. Sea anemone
  • C. Hydra
  • D. Jellyfish

Explanation: Corals are unique among coelenterates because they secrete a hard exoskeleton made of calcium carbonate (CaCO3), which is distinct from the hydrostatic skeleton found in other coelenterates like sea anemones, hydras, and jellyfish. These other organisms use fluid pressure within their bodies to maintain shape and support movement. Thus, corals are the exception to the typical hydrostatic skeleton seen in this group.

Why the other options are wrong
  • B. This option is incorrect. Sea anemones have a soft body and use their fluid-filled cavity for support, characteristic of a hydrostatic skeleton.
  • C. This option is incorrect. Hydra rely on a hydrostatic skeleton for their structure and movement, utilizing fluid pressure within their body cavity.
  • D. This option is incorrect. Jellyfish are well-known for their reliance on a hydrostatic skeleton, where the bell-like body structure is supported by internal fluid pressure.

Q68. Lungs are _ in srcin.

  • A. Ectodermal
  • B. Endodermal
  • C. Mesodermal
  • D. Preformed

Explanation: The correct answer is Endodermal. The endoderm, one of the three primary germ layers formed during embryonic development, is responsible for the formation of the respiratory tract lining, including the lungs. This layer also forms other vital internal organs such as the liver, pancreas, and parts of the digestive system. The ectoderm and mesoderm, while important for forming other bodily structures, do not contribute to the primary functional tissue of the lungs. 'Preformed' is unrelated to germ layer origins and lung development.

Why the other options are wrong
  • A. The ectoderm is the outermost germ layer and forms structures such as the skin and nervous system. While it contributes to the nasal cavity lining, it is not responsible for forming the lungs' primary functional tissue.
  • C. The mesoderm is the middle germ layer, forming muscles, bones, and connective tissues. It contributes to the structural components of the lungs but not the primary functional lining.
  • D. 'Preformed' does not pertain to germ layer origin; it refers to something that is already fully formed, which is irrelevant to lung development.

Q69. The particular array of chromosomes that an individual possessed is called its:

  • A. Genotype
  • B. Phenotype
  • C. Karyotype
  • D. Genome

Explanation: The correct answer is Karyotype. A karyotype is a visual profile of an individual's chromosomes, showing the number and appearance of chromosomes, including their size, shape, and any abnormalities. It is often used in genetic testing to identify chromosomal disorders.The term Genotype refers to the specific set of genes an organism carries, which influences its traits but doesn't specifically denote the chromosomal structure.Phenotype describes the observable characteristics or traits of an organism, which are influenced by both its genotype and environmental factors.Genome refers to the entire set of genetic material in an organism but doesn't focus on the physical arrangement or appearance of chromosomes as a karyotype does.

Why the other options are wrong
  • A. The genotype is the genetic constitution of an organism, represented by its specific alleles. It refers to the genes, not the physical arrangement of chromosomes.
  • B. Phenotype describes the observable traits of an organism, such as height and eye color, which result from the interaction of its genotype with the environment.
  • D. The genome encompasses all the genetic material in an organism's cells, including the full DNA sequence, but doesn't specifically refer to the arrangement of chromosomes.

Q70. An Ascus develops:

  • A. 2-Ascospores
  • B. 4-Ascospores
  • C. 6-Ascospores
  • D. 8-Ascospores

Explanation: Typically, a single ascus will contain eight ascospores which are produced by meiosis followed by a mitotic division.

Why the other options are wrong
  • A. This is incorrect. An ascus does not typically develop just two ascospores.
  • B. This is incorrect. While some fungi may sometimes produce four ascospores, the typical number is not four.
  • C. This is incorrect. Six ascospores are not commonly produced in a single ascus.

Q71. The cell wall of fungus like protista is composed of:

  • A. Chitin
  • B. Cellulose
  • C. Murein
  • D. Lignin

Explanation: The cell wall of fungus like protista is composed of chitin.

Why the other options are wrong
  • B. Cellulose is a polysaccharide that is not found in the cell walls of fungi. Instead, it is a primary component of the cell walls of plants and some algae, providing structural support and rigidity.
  • C. Murein, also known as peptidoglycan, is found in the cell walls of bacteria, not fungi. It provides structural strength and shape to bacterial cell walls.
  • D. Lignin is a complex organic polymer found in the cell walls of plants, particularly in wood and bark. It provides rigidity and does not occur in fungal cell walls.

Q72. If the coding sequence on the DNA is AATIGCT, the sequence in the mRNA will be:

  • A. AAUOCGT
  • B. UUAACGA
  • C. TTAACGA
  • D. UUTTCGT

Explanation: RNA polymerase uses one of the DNA strands (the template strand) as a template to make a new, complementary RNA molecule. The base sequence complementary to AATTGCT is UUAACGA as Adenine in DNA pairs with Uracil in mRNA , Thymine in DNA pairs with Adenine in mRNA, and Guanine pairs with Cytosine.

Why the other options are wrong
  • A. This sequence is incorrect because it includes the letter 'O', which is not a valid nucleotide base in RNA.
  • C. This sequence is incorrect because it contains thymine (T), which is not present in RNA. Thymine in DNA is replaced by uracil (U) in RNA.
  • D. This sequence is incorrect because it includes thymine (T), which is not found in RNA. Additionally, the pairing does not adhere to the correct transcription rules.

Q73. Gene and chromosomes show parallel behavior except:

  • A. Number
  • B. Inheritance
  • C. Heredity
  • D. Composition

Explanation: Genes are specific sequences of nucleotides within DNA that reside on chromosomes. A chromosome is a larger structure that contains many genes. Therefore, while they both play roles in inheritance, heredity, and share similar composition, they do not match in number. Humans typically have 23 pairs of chromosomes, each containing multiple genes. Thus, the number is the key aspect where they do not exhibit parallel behavior. Options B, C, and D are incorrect because they describe areas where genes and chromosomes show parallel behavior.

Why the other options are wrong
  • B. Both genes and chromosomes play crucial roles in inheritance, transmitting genetic information from one generation to the next. Therefore, they show parallel behavior in terms of inheritance.
  • C. Genes and chromosomes both contribute to heredity, which is the passing of traits from parents to offspring. Hence, they exhibit parallelism in heredity.
  • D. Both genes and chromosomes are composed of DNA, which is made up of nucleotides. Therefore, they are parallel in terms of their composition.

Q74. 'Mortal stay‘ implies:

  • A. Life that a man will have after death
  • B. Life spent in the company of friend
  • C. Life passed in hostel without studying
  • D. Life in this world which is short-lived

Explanation: Mortal sta refers to the temporar life spent before one's death, so option D seems to be the accurate.

Why the other options are wrong
  • A. This option refers to life after death, which is not applicable to 'mortal' as it pertains to life that is finite and subject to death.
  • B. While spending life with friends can be meaningful, this does not capture the essence of 'mortal,' which focuses on the temporary nature of life.
  • C. This option describes a specific lifestyle choice rather than the nature of life itself, which 'mortal' addresses.

Q75. Chlorophyll is protected from intense light by:

  • A. Phytochrome
  • B. Phytokinin
  • C. Phytocyanin
  • D. Carotenoids

Explanation: Some carotenoids protect chlorophyll from intense light by absorbing and dissipating excessive light energy, rather than transferring energy to chlorophyll.

Why the other options are wrong
  • A. Phytochromes are red (R)/far-red (FR) light photoreceptors that play fundamental roles in photoperception of the light environment and the subsequent adaptation of plant growth and development.
  • B. Phytokinins(Cytokinins) are essential plant hormones. By stimulating cell division, they regulate shoot meristem size, leaf primordia number, and leaf and shoot growth.
  • C. Phycocyanin is a pigment-protein complex that biologically functions cooperatively with chlorophyll in photosynthesis. Specifically, phycocyanin increases the efficiency of chlorophyll's oxygen production under low light conditions.

Q76. Replication of DNA occurs during:

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

Explanation: DNA replication occurs during S-stage of interphase.

Why the other options are wrong
  • B. During prophase chromosomes condense, nucleolus disappears, nuclear envelope disintegrates into vesicles, centrioles move to opposite poles and mitotic spindle forms as microtubules are assembled.
  • C. In metaphase, chromosomes get lined up at the metaphase plate.
  • D. In anaphase, the sister chromatids separate from each other and are pulled towards opposite ends of the cell.

Q77. Human arm is homologous with:

  • A. Seal's flipper
  • B. Octopus tentacle
  • C. Bird's wing
  • D. Both Seal's flipper and Bird's wing

Explanation: Anatomically, the human arm, the flippers of seals, and the wings of the birds are the forelimbs containing similar bones. These forelimbs have a common origin and similar anatomical features but have been modified to perform different functions. Flippers allow the seal to swim, birds fly using their wings and humans perform a variety of functions using the arms. Such structures are homologous to each other.

Why the other options are wrong
  • A. This option is partially correct. The human arm is homologous with the seal's flipper due to their common evolutionary origin and similar bone structures.
  • B. This option is incorrect. Octopus tentacles are not homologous to human arms as they do not share a common evolutionary origin or similar structure.
  • C. This option is partially correct. The human arm is homologous with the bird's wing because they share a common evolutionary ancestor and similar bone structures.

Q78. A specific nudeotide sequence on DNA molecule to which RNA polymerase attaches to initiate transcription of mRNA from a gene is called:

  • A. Poly genes
  • B. Genome
  • C. Promoter
  • D. Pleiotropy

Explanation: The first step in transcription is initiation, when the RNA pol binds to the DNA upstream (5′) of the gene at a specialized sequence called a promoter.

Why the other options are wrong
  • A. Polygenes contribute to complex traits and are not directly involved in the initiation of transcription.
  • B. The genome encompasses the entire genetic material of an organism, which includes many genes, but does not specifically refer to the site where transcription initiates.
  • D. Pleiotropy describes a situation where one gene influences multiple phenotypic traits, and it is unrelated to the initiation of transcription.

Q79. All of the following belong to phylum Protista except:

  • A. Protomycota
  • B. Gymnomycota
  • C. Oomycota
  • D. Deuteromycota

Explanation: Phylum Deuteromycota is a polyphyletic group of asexually-reproducing fungi that do not display a sexual phase; they are known as imperfect.

Why the other options are wrong
  • A. Protomycota is an informal grouping of certain protists. Historically, they were sometimes included in Protista.
  • B. Gymnomycota, often referred to as slime molds, are a part of the Protista kingdom.
  • C. Oomycota, commonly known as water molds, are considered part of the Protista kingdom.

Q80. A special protein carrier in plasma membrane is:

  • A. Catalase
  • B. Lipase
  • C. Permease
  • D. Arginase

Explanation: The correct answer is Permease, which is a protein carrier in the plasma membrane. Permease functions by specifically binding to molecules on one side of the membrane and facilitating their movement across the membrane through a conformational change. This is essential for processes like nutrient uptake and waste removal.Other options like Catalase, Lipase, and Arginase are enzymes with roles unrelated to membrane transport. Catalase breaks down hydrogen peroxide, Lipase digests lipids, and Arginase participates in the urea cycle, making them incorrect choices for this question.

Why the other options are wrong
  • A. Catalase is an enzyme that breaks down hydrogen peroxide into water and oxygen. It is not involved in transporting molecules across the plasma membrane.
  • B. Lipase is an enzyme that aids in the digestion of lipids (fats). It does not function as a protein carrier in the plasma membrane.
  • D. Arginase is an enzyme involved in the urea cycle that converts arginine to urea and ornithine. It does not act as a protein carrier in the plasma membrane.

Q81. The theory of new creation was composed by:

  • A. George Cuvier
  • B. James Hustion
  • C. Louis Agassiz
  • D. Alfred Russel Wallace

Explanation: Louis Agassiz was known for opposing Darwin's theory of evolution and believed that new species were created through divine intervention, a viewpoint that is consistent with the theory of new creation. George Cuvier, while a pioneering paleontologist, focused on catastrophism rather than new creation. James Hustion does not have a notable connection to this theory, and Alfred Russel Wallace was a co-developer of the theory of natural selection, making him an unlikely proponent of new creation.

Why the other options are wrong
  • A. George Cuvier is known for establishing extinction as a fact but did not propose the theory of new creation. Instead, he was a proponent of catastrophism.
  • B. James Hustion is not recognized in historical records for contributions to the theory of new creation or related fields.
  • D. Alfred Russel Wallace is noted for independently conceiving the theory of evolution through natural selection, in parallel to Darwin, not for new creation.

Q82. The bone dissolving cells are called:

  • A. Osteoclast
  • B. Osteoblasts
  • C. Osteocytes
  • D. Fibroblast

Explanation: Osteoclasts are the bone-dissolving cells responsible for bone resorption. Derived from monocytes, they are large, multinucleated cells that break down bone tissue by secreting enzymes and acids, creating resorption pits. This process is vital for bone remodeling and calcium release into the bloodstream. Osteoblasts then fill these pits with new bone tissue, maintaining bone health.The other cell types serve different functions: Osteoblasts create new bone tissue, osteocytes maintain the bone matrix, and fibroblasts are involved in the production of connective tissue, not bone resorption.

Why the other options are wrong
  • B. Osteoblasts are responsible for forming new bone tissue by synthesizing and secreting the bone matrix. They do not dissolve bone; instead, they contribute to its construction.
  • C. Osteocytes are mature bone cells embedded within the bone matrix. Their role is to maintain bone tissue, not to dissolve it.
  • D. Fibroblasts are cells associated with connective tissue, producing extracellular matrix and collagen. They are not involved in bone resorption.

Q83. The response of a plant related to the length of the day and night is called:

  • A. Photo-receptor
  • B. Photo-taxis
  • C. Photo-tropism
  • D. Photo-Periodism

Explanation: Photoperiodism is the ability of plants and animals to measure environmental day length (photoperiod), typically by monitoring night length. This process underlies a biological calendar. Photoperiod is inversely correlated to the nightly duration of melatonin secretion in animals.

Why the other options are wrong
  • A. Photo-receptors are cells or molecules in plants that detect light, initiating responses like growth and development, but they do not relate directly to day and night length.
  • B. Photo-taxis involves movement towards or away from light, typically in organisms like bacteria, and is not related to day and night cycles.
  • C. Photo-tropism refers to the growth direction of plants in response to light direction, not the length of day and night.

Q84. Which of the following polymers contain nitrogen?

  • A. PVC
  • B. Terylene
  • C. Nylon
  • D. Teflon

Explanation: Nylon is a synthetic polymer that contains nitrogen in its chemical structure.

Why the other options are wrong
  • A. PVC (Polyvinyl Chloride) is primarily made of carbon, hydrogen, and chlorine atoms, and does not include nitrogen in its structure.
  • B. Terylene, also known as polyethylene terephthalate (PET), consists of carbon, hydrogen, and oxygen atoms. There is no nitrogen present in its chemical structure.
  • D. Teflon consists of carbon and fluorine atoms, derived from tetrafluoroethylene, and does not contain nitrogen.

Q85. Providing heat to the following reaction causes it to shift to the rightCo2(2) + 2H2O(g) → CH4(g) + 2O2(g)The reaction can therefore be described as:

  • A. Spontaneous
  • B. Adiabatic
  • C. Endothermic
  • D. Exothermic

Explanation: Endothermic reactions consume heat for it to proceed towards the right.

Why the other options are wrong
  • A. A spontaneous reaction occurs without the need for continuous external energy. It does not describe whether heat is absorbed or released.
  • B. An adiabatic process involves no heat exchange with the surroundings. This term does not apply to reactions where heat is explicitly added or absorbed.
  • D. An exothermic reaction releases heat to the surroundings. Since this reaction requires heat to proceed, it is not exothermic.

Q86. The major sources responsible for the presence of NO, N2O, NO2 in the atmosphere is / are:

  • A. Fertilizers
  • B. Biological decay of organic matter
  • C. Fossil fuel combustion
  • D. All of these

Explanation: Fossil fuel combustion is the major source of NO, NO2, and N2O in the atmosphere. This process occurs in vehicles, industrial facilities, and power plants, where high temperatures lead to the formation of nitrogen oxides. Fertilizers and biological decay are lesser sources and primarily contribute to other types of nitrogen emissions, such as ammonia and organic nitrogen compounds, rather than directly to nitrogen oxides.

Why the other options are wrong
  • A. While fertilizers do contribute to nitrogen emissions, they primarily release ammonia (NH3) rather than NO, NO2, or N2O. The conversion to these gases occurs through processes like nitrification and denitrification, which are not the main pathways for atmospheric NOx emissions.
  • B. Biological decay can release nitrogen compounds, but the process is not a major direct source of NO, NO2, or N2O in the atmosphere. The conversion of organic nitrogen to these gases is indirect and not as significant as fossil fuel combustion.
  • D. While fertilizers and biological decay contribute to nitrogen emissions, they are not the major sources of NO, NO2, and N2O compared to fossil fuel combustion.

Q87. Polyhydroxy aldehydes or ketones are known as:

  • A. Carbohydrates
  • B. Proteins
  • C. Lipids
  • D. Vitamins

Explanation: Carbohydrates are organic compounds made up of carbon, hydrogen, and oxygen atoms. They are commonly referred to as sugars or saccharides. Polyhydroxy aldehydes or ketones are a specific type of carbohydrate. Examples include glucose, fructose, and sucrose.

Why the other options are wrong
  • B. Proteins are polymers of amino acids linked by peptide bonds. They are essential for numerous biological functions, including enzymatic activity and cellular structure, but they do not include polyhydroxy aldehydes or ketones in their structure.
  • C. Lipids are hydrophobic or amphipathic molecules, including fats and oils, that are primarily involved in forming cell membranes and energy storage. They do not consist of polyhydroxy aldehydes or ketones.
  • D. Vitamins are organic molecules required in small amounts for proper metabolic function, often acting as coenzymes. They do not include polyhydroxy aldehydes or ketones as their structural basis.

Q88. Sucrose is considered as:

  • A. Monosaccharides
  • B. Disaccharides
  • C. Polysaccharides
  • D. None of these

Explanation: Sucrose is a disaccharide that is formed when two monosaccharide sugars are joined by glycosidic linkage.

Why the other options are wrong
  • A. Monosaccharides are the simplest form of carbohydrates, consisting of a single sugar unit, such as glucose or fructose. Sucrose, however, is composed of two sugar units, not one.
  • C. Polysaccharides are complex carbohydrates consisting of multiple monosaccharide units. Examples include starch and cellulose. Sucrose, with only two sugar units, does not fall into this category.
  • D. This option is incorrect because sucrose is indeed a disaccharide, as stated in option B.

Q89. High molecular mass compound was hydrolyzed the product was analyzed and found to be amino acid. The compound is:

  • A. Protein
  • B. Carbohydrate
  • C. Lipid
  • D. Vitamins

Explanation: Proteins are large biomolecules composed of amino acids linked together by peptide bonds. When a high molecular mass compound is hydrolyzed and the product is found to be an amino acid, it indicates that the compound was a protein. Proteins are essential for various biological processes and play a crucial role in the structure and function of cells and tissues.

Why the other options are wrong
  • B. Carbohydrates are composed of sugar units and break down into monosaccharides like glucose, not amino acids. Thus, a compound hydrolyzing to amino acids cannot be a carbohydrate.
  • C. Lipids are composed of fatty acids and glycerol. They do not hydrolyze to produce amino acids, but rather components like fatty acids and alcohols.
  • D. Vitamins are organic compounds required in small quantities for normal metabolism. They do not hydrolyze into amino acids.

Q90. The enzymes functions are optimum at:

  • A. Specific Temperature
  • B. Specific pH
  • C. Specific Co-enzyme
  • D. All the above

Explanation: The correct answer is 'All the above' because enzymes require specific conditions to function at their best. Each enzyme has an optimum temperature and pH that maximizes its activity. Additionally, certain enzymes depend on co-enzymes to facilitate their biochemical reactions. The other options, while individually important, do not capture the full range of factors that contribute to optimal enzyme function.

Why the other options are wrong
  • A. Enzymes often have an optimum temperature at which their activity is maximized. Deviations from this temperature can lead to decreased enzyme activity.
  • B. Each enzyme has an optimum pH level that enhances its activity. Outside of this pH range, the enzyme's structure may be disrupted, leading to reduced function.
  • C. Some enzymes require specific co-enzymes to function effectively. While important, this option alone does not encompass the full range of optimal conditions for enzyme activity.

Q91. Which of the following is a lewis acid?

  • A. CH3OH
  • B. AlCl3
  • C. NH3
  • D. CH3OCH3

Explanation: The correct answer is AlCl3, which is a Lewis acid because it can accept an electron pair. The aluminum atom in AlCl3 has an empty p-orbital, making it capable of accepting electron pairs from Lewis bases, such as when it reacts with chloride ions (Cl-) to form [AlCl4]-. This behavior is a defining characteristic of Lewis acids, which are electron pair acceptors.On the other hand, CH3OH (methanol) is not a Lewis acid because it cannot accept electron pairs; instead, it can donate a proton, acting as a Brønsted-Lowry acid. NH3 (ammonia) is a Lewis base because it can donate its lone pair of electrons, and CH3OCH3 (dimethyl ether) is also a Lewis base due to the lone pairs on the oxygen atom available for donation.

Why the other options are wrong
  • A. Methanol (CH3OH) acts as a Brønsted-Lowry acid by donating a proton (H+), but it does not have the capacity to accept an electron pair, which is required to be a Lewis acid. Therefore, it is not a Lewis acid.
  • C. Ammonia (NH3) is a Lewis base, not a Lewis acid. It has a lone pair of electrons on the nitrogen atom, which it can donate to form a coordinate covalent bond, characteristic of a Lewis base.
  • D. Dimethyl ether (CH3OCH3) is also a Lewis base because it has lone pairs on the oxygen atom, which can be donated to an electron acceptor. It does not act as an electron pair acceptor, so it is not a Lewis acid.

Q92. Ethanol (CH3CH2OH) and dimethyl ether (CH3OCH3) are the best considered as:

  • A. Functional isomers
  • B. Stereoisomers
  • C. Enantiomers
  • D. Diastereomers

Explanation: Ethanol and dimethyl ether are functional isomers because they share the same molecular formula, C2H6O, but differ in their functional groups: ethanol is an alcohol, and dimethyl ether is an ether. This distinguishes them as functional isomers, a type of structural isomerism where compounds differ in the type of functional group present.Options B, C, and D are incorrect because stereoisomers, enantiomers, and diastereomers all involve the same connectivity of atoms but differ in spatial arrangement, which is not the case here, as ethanol and dimethyl ether differ in their connectivity and functional groups.

Why the other options are wrong
  • B. Stereoisomers have identical molecular formulas and atom connectivity but differ in the three-dimensional orientation of their atoms. This is not applicable to ethanol and dimethyl ether, as they differ in connectivity.
  • C. Enantiomers are stereoisomers that are non-superimposable mirror images of each other. Ethanol and dimethyl ether do not fit this description as they differ in their molecular connectivity and not in spatial orientation.
  • D. Diastereomers are stereoisomers that are not mirror images of each other. Ethanol and dimethyl ether are not diastereomers because they do not share the same structural framework or connectivity.

Q93. A tertiary carbon is bonded directly to:

  • A. 2 Hydrogens
  • B. 2 Carbons
  • C. 3 Carbons
  • D. 4 Carbons

Explanation: A tertiary carbon is a carbon atom bonded directly to three other carbon atoms. This classification helps in understanding the structure and reactivity of hydrocarbons. The correct option is Option C: 3 Carbons. Other options are incorrect as they either involve fewer carbon atoms or incorrectly include hydrogen atoms, which do not change the classification of the carbon atom in this context. Option D is incorrect as it describes a quaternary carbon, which is bonded to four carbon atoms.

Why the other options are wrong
  • A. Incorrect. A tertiary carbon is bonded to three other carbon atoms, not hydrogen atoms.
  • B. Incorrect. A tertiary carbon must be bonded to three other carbon atoms.
  • D. Incorrect. A carbon atom bonded to four other carbon atoms would be a quaternary carbon, not tertiary.

Q94. When acetylene is passed through hot iron tube at 400 oC, it gives:

  • A. Benzene
  • B. Toluene
  • C. O-Xylene
  • D. Metaxylene

Explanation: Acetylene on passing through a red hot iron tube undergoes cyclic polymerization. Three of the acetylene molecules polymerise to form benzene.

Why the other options are wrong
  • B. Incorrect. Toluene is not formed in this reaction; it requires different starting materials and conditions.
  • C. Incorrect. O-Xylene is a derivative of benzene and is not formed directly from acetylene under these conditions.
  • D. Incorrect. Metaxylene is another derivative of benzene and is not produced from acetylene in this reaction.

Q95. Which of the following compounds will react with methyl magnesium Iodide followed by acid hydrolysis to give ethyl alcohol?

  • A. Ethylene
  • B. Acetone
  • C. Acetaldehyde
  • D. Formaldehyde

Explanation: When formaldehyde (CH2O) reacts with methyl magnesium iodide (CH3MgI), followed by acid hydrolysis, it gives ethyl alcohol (ethanol). The Grignard reagent reacts with the formaldehyde carbonyl group, forming a compound that can be hydrolyzed to yield ethyl alcohol.The reaction can be represented as follows:CH2O + CH3MgI → CH3CH2OH

Why the other options are wrong
  • A. Ethylene, being an unsaturated hydrocarbon without a carbonyl group, cannot react with a Grignard reagent to form an alcohol. Grignard reagents require a carbonyl group to initiate the reaction.
  • B. Acetone, a ketone, reacts with a Grignard reagent to form a tertiary alcohol, not ethyl alcohol. The carbonyl carbon of acetone is attacked by the Grignard reagent, leading to a different alcohol structure.
  • C. Acetaldehyde, an aldehyde, would react with methyl magnesium iodide to form a secondary alcohol. However, this does not match the desired ethyl alcohol product specified in the question.

Q96. Diethyl ether and Methyl propyl ether are:

  • A. Conformational isomers
  • B. Metamers
  • C. Geometrical isomers
  • D. Enantiomers

Explanation: Metamers are the compounds having the same molecular formula but different position of atoms or groups on the either side of bridging functional groups.

Why the other options are wrong
  • A. Conformational isomers are different spatial arrangements of a molecule that can be converted into one another by rotation around a single bond. Diethyl ether and Methyl propyl ether have different carbon chains, not just different conformations, so this is incorrect.
  • C. Geometrical isomerism occurs due to restricted rotation around a double bond, presenting different spatial arrangements. As ethers lack such restrictions, this is incorrect for the given compounds.
  • D. Enantiomers are non-superimposable mirror images of each other, typically involving chiral centers. Neither diethyl ether nor methyl propyl ether has chiral centers, so they cannot be enantiomers.

Q97. Acetic acid reacts with methyl alcohol in the presence of acid catalyst to give:

  • A. Ethyl formate
  • B. Ethyl acetate
  • C. Methyl formate
  • D. Methyl acetate

Explanation: This is the correct product formed by the reaction between acetic acid and methyl alcohol in the presence of an acid catalyst. The reaction is an esterification reaction, where the -OH group of acetic acid reacts with the -OH group of methyl alcohol to form water and methyl acetate.

Why the other options are wrong
  • A. Incorrect. Ethyl formate is produced from ethyl alcohol and formic acid, not from acetic acid and methyl alcohol.
  • B. Incorrect. Ethyl acetate results from the reaction of ethyl alcohol with acetic acid, not methyl alcohol.
  • C. Incorrect. Methyl formate is formed by the reaction of methyl alcohol with formic acid, not acetic acid.

Q98. The characteristic reaction of carboxylic acid is:

  • A. Electrophilic substitution
  • B. Nucleophilic substitution
  • C. Electrophilic addition
  • D. Nucleophilic addition

Explanation: The carboxyl (COOH) group is named after the carbonyl group (C=O) and a hydroxyl group. In general, carboxylic acids undergo a nucleophilic substitution reaction where the nucleophile (-OH) is substituted by another nucleophile (Nu).

Why the other options are wrong
  • A. While carboxylic acids can undergo electrophilic substitution reactions, such as in aromatic carboxylic acids, these are not their primary characteristic reactions. Thus, this option is incorrect.
  • C. Carboxylic acids are not known for undergoing electrophilic addition reactions. This type of reaction is more typical for alkenes and alkynes. Therefore, this option is incorrect.
  • D. Nucleophilic addition is typical of aldehydes and ketones. Due to the resonance stabilization in carboxylic acids, they do not readily undergo nucleophilic addition reactions. Hence, this option is incorrect.

Q99. Which of the following compounds does not give iodoform test on reaction with I2 and NaOH?

  • A. Propanone
  • B. Ethanol
  • C. Butanone
  • D. Methanol

Explanation: It does not have methyl group attached to alpha carbon so it will not give idoform test

Why the other options are wrong
  • A. Propanone, also known as acetone, contains a methyl ketone group, which reacts with I2 and NaOH to give a positive iodoform test.
  • B. Ethanol contains the CH3CH(OH)- group, which upon oxidation forms acetaldehyde, giving a positive iodoform test.
  • C. Butanone also contains a methyl ketone group, enabling it to produce a positive iodoform test.

Q100. Which of the following substitutents is an Ortho and Para director and ring deactivating?

  • A. –OH
  • B. –NH2
  • C. –Cl
  • D. –OCH3

Explanation: In electrophilic aromatic substitution, the nature of the substituent on the benzene ring plays a crucial role in determining the position of new substituents and the reactivity of the ring. Ortho-para directors are groups that direct incoming electrophiles to the 2, 4 (ortho, para) positions. While most ortho-para directors are activating, -Cl is an exception as it directs due to resonance but deactivates due to a strong inductive effect. This means it reduces the overall reactivity of the benzene ring but still allows for substitution at ortho and para positions.In contrast, –OH and –NH2 groups are strong activators, and –OCH3 is moderately activating; all increase the reactivity of the benzene ring and direct electrophiles to ortho and para positions without deactivating the ring.

Why the other options are wrong
  • A. The –OH group is an activator due to its electron-donating resonance effect, making the benzene ring more reactive. It directs incoming groups to the ortho and para positions, but it is not deactivating.
  • B. The –NH2 group is a strong activator and an ortho-para director due to its electron-donating resonance effect. It increases the electron density of the benzene ring, making it not deactivating.
  • D. The –OCH3 group is an activating group due to its electron-donating resonance effect, leading to increased reactivity of the benzene ring. It is an ortho-para director but not deactivating.

Q101. Which of the following compounds undergo nitration most readily?

  • A. Benzene
  • B. Toluene
  • C. Benzoic acid
  • D. Nitrobenzene

Explanation: The correct answer is Toluene. Toluene undergoes nitration much faster than benzene due to the presence of a methyl group. This group donates electron density to the ring, particularly enhancing the reactivity at the ortho and para positions, making the electrophilic aromatic substitution process more favorable.Why the other options are incorrect:Benzene: While benzene can undergo nitration, it lacks activating groups, making it less reactive compared to toluene.Benzoic Acid: The carboxyl group is a deactivating group, reducing electron density in the ring and hindering electrophilic attack.Nitrobenzene: The nitro group is a strong deactivator, making further nitration extremely difficult due to the electron-deficient ring.

Why the other options are wrong
  • A. Benzene can undergo nitration but does so at a slower rate compared to compounds with electron-donating groups. Its lack of substituents makes it less reactive in electrophilic aromatic substitution reactions.
  • C. Benzoic acid contains a carboxyl group, which is a deactivating group. This group pulls electron density away from the benzene ring, reducing its reactivity towards electrophilic substitution reactions like nitration.
  • D. Nitrobenzene already has a nitro group, which is a strongly deactivating group, making the ring electron-deficient. This significantly reduces its ability to undergo further nitration.

Q102. Which of the following is not a ferromagnetic material?

  • A. Iron
  • B. Nickel
  • C. Cobalt
  • D. Barium

Explanation: Barium is not a ferromagnetic material. Ferromagnetic materials have a strong magnetic response to an external magnetic field, and they can retain their magnetization even after the external field is removed. Iron, Nickel, and Cobalt are examples of ferromagnetic materials. Barium is a diamagnetic material, which means it is weakly repelled by both poles of a magnet. It does not exhibit the strong magnetic properties characteristic of ferromagnetic materials. Therefore, option d is correct.

Why the other options are wrong
  • A. It is a ferromagnetic material.
  • B. It is a ferromagnetic material.
  • C. It is a ferromagnetic material.

Q103. Milk sugar is pasteurized by heating for 15 seconds at the temperature of:

  • A. 60 oC
  • B. 71 oC
  • C. 50 oC
  • D. 80 oC

Explanation: Pasteurization of milk, requires temperatures of about 63 °C (145 °F) maintained for 30 minutes or, alternatively, heating to a higher temperature, 72 °C (162 °F), and holding for 15 seconds.

Why the other options are wrong
  • A. This temperature is too low for effective pasteurization of milk within the time frame of 15 seconds. Typical pasteurization requires higher temperatures to ensure safety.
  • C. This temperature is significantly below the required threshold for pasteurization. At 50°C, milk would not be pasteurized properly, leaving it unsafe for consumption.
  • D. While this temperature is higher than necessary, it is above the typical range used for standard pasteurization practices, which aim to balance safety and taste preservation.

Q104. Which one of the following is most ionic?

  • A. NaCl
  • B. MgCl2
  • C. KCl
  • D. AlCl3

Explanation: The correct answer is KCl because it forms the most ionic bond among the options provided. Potassium (K) is larger and has a lower charge density than sodium (Na), making it easier to lose its valence electron and form a K+ cation. According to Fajan's rules, larger cations with a lower charge density form more ionic bonds, which is why KCl is more ionic than NaCl. NaCl is ionic, but sodium's smaller size compared to potassium leads to a slightly higher charge density, resulting in less ionic character compared to KCl.MgCl2 has a +2 charge on magnesium, which increases the covalent character of the bond due to polarization effects.AlCl3 is more covalent due to aluminum's +3 charge, which causes significant polarization of the chloride ions. The ability of AlCl3 to form a dimer also supports its covalent nature.

Why the other options are wrong
  • A. Sodium chloride (NaCl) is a classic example of an ionic compound. Sodium (Na) loses one electron to form a Na+ cation, and chlorine (Cl) gains an electron to form a Cl- anion, resulting in a strong ionic bond. However, NaCl is less ionic than KCl because sodium is smaller and has a slightly higher charge density than potassium.
  • B. Magnesium chloride (MgCl2) involves magnesium (Mg) losing two electrons to form a Mg2+ cation. The +2 charge on magnesium increases the covalent character of the bond compared to compounds with +1 cations like KCl and NaCl.
  • D. Aluminum chloride (AlCl3) is less ionic and more covalent in nature. Aluminum (Al) forms a +3 charge, which polarizes the chloride ions, increasing the covalent character. Additionally, AlCl3 can form a dimer (Al2Cl6), further indicating its covalent nature.

Q105. The compound used in borax bead test for the detection of basic redicals to form colored bead is:

  • A. H2BO2
  • B. (C2H5)3BO3
  • C. Ca2B6O115H2O
  • D. Na2B4O710H2O

Explanation: Per one molecule of borax, there are 10 molecules of water of crystallization. Hence, metaborate is formed in the borax bead test.

Why the other options are wrong
  • A. H₂BO₂ (Metaboric acid): Although metaboric acid forms during the heating of borax, it is not the compound used to create the colored bead in the test. Borax is the initial reagent that undergoes changes to form the final bead.
  • B. (C₂H₅)₃BO₃ (Triethyl borate): This organic ester is unrelated to the borax bead test as it doesn't possess the necessary properties to form a glassy bead with metal ions.
  • C. Ca₂B₆O₁₁·5H₂O (Calcium borate): This compound is a borate mineral, not the standard reagent used in the borax bead test. The test specifically utilizes sodium tetraborate (borax).

Q106. Milk of magnesia is used for treatment of acidity in stomach, its formula is:

  • A. Mg(OH)2
  • B. MgSO4
  • C. Ca(OH)2
  • D. CaSO4

Explanation: Milk of magnesia is a suspension of magnesium hydroxide, with the chemical formula Mg(OH)2. It is an effective antacid that neutralizes stomach acid, providing relief from heartburn and indigestion. The reaction with stomach acid produces magnesium chloride and water, which reduces acidity. The other options, MgSO4, Ca(OH)2, and CaSO4, either have different uses or are not suitable for treating stomach acidity.

Why the other options are wrong
  • B. MgSO4 (Magnesium Sulfate): Known as Epsom salt, it is not used to treat acidity. It is often used for muscle relaxation and as a laxative, not for neutralizing stomach acid.
  • C. Ca(OH)2 (Calcium Hydroxide): Also known as slaked lime, this compound can neutralize acids but is not safe or effective as a regular antacid due to its strong alkaline nature.
  • D. CaSO4 (Calcium Sulfate): Known as gypsum, this compound is primarily used in construction materials and has no role in treating stomach acidity.

Q107. Select the true statement about the amorphous solids:

  • A. Amorphous substances have a sharp melting point
  • B. Amorphous substances do not have a fixed melting point
  • C. Amorphous substances have proper geometrical shapes
  • D. The particles in amorphous substances are arranged in an orderly manner

Explanation: Amorphous solids, unlike crystalline solids, do not have a fixed melting point. This is because they lack the ordered structure that characterizes crystalline materials. Instead, they soften gradually over a range of temperatures. For example, glass softens before melting completely. Amorphous solids have a disordered atomic or molecular structure, which results in their unique properties such as isotropic behavior and lack of sharp melting points. Option B correctly identifies this characteristic, whereas the other options incorrectly attribute properties of crystalline solids to amorphous ones.

Why the other options are wrong
  • A. This is incorrect. Amorphous solids do not have a sharp melting point; they soften over a range of temperatures.
  • C. This is incorrect. Amorphous solids do not have a defined geometric shape because their particles are arranged randomly.
  • D. This is incorrect. The atomic or molecular arrangement in amorphous solids is disordered, lacking the long-range order found in crystalline solids.

Q108. Both NaNO3 an CaCO3 crystallize in Rhombohedral forms therefore they are:

  • A. Allotropes
  • B. Polymorphous
  • C. Isomorphous
  • D. None of these

Explanation: Two or more substances having the same crystal structure called isomorphous.

Why the other options are wrong
  • A. Allotropes refer to different structural forms of the same element, exhibiting different physical properties. Since NaNO3 and CaCO3 are different compounds, not different forms of the same element, this option is incorrect.
  • B. Polymorphous substances are those that exist in more than one crystal form. This term typically applies to a single substance, not to comparing different substances like NaNO3 and CaCO3, making this option incorrect.
  • D. This option is incorrect because 'Isomorphous' is the correct answer.

Q109. Pure water freezes at 0 oC and boils at 100 oC at standard conditions. Calcium chloride was added to pure water. What do you expect about its freezing point and boiling point?

  • A. No change in its freezing point and boiling point
  • B. Freezing point increases and boiling point decreases.
  • C. Freezing point increases and boiling point increases
  • D. Freezing point decreases and boiling point increases

Explanation: The presence of impurities in a substance lowers the melting point but increases the boiling point of the substance.

Why the other options are wrong
  • A. This is incorrect. Adding a solute to a solvent typically changes its freezing and boiling points.
  • B. This is incorrect. The effect of adding a solute is generally the opposite: lowering freezing points and raising boiling points.
  • C. Partially incorrect. While the boiling point increases, the freezing point actually decreases with the addition of a solute.

Q110. Which of the following ions play important role in the transportation of carbon dioxide?

  • A. Sodium
  • B. Potassium
  • C. Bicarbonate
  • D. Chloride

Explanation: The majority of carbon dioxide is transported as bicarbonate ions. This is because erythrocytes have a high activity of carbonic anhydrase, an enzyme that catalyzes the reaction between carbon dioxide and water.

Why the other options are wrong
  • A. Sodium (Na+) ions are essential for maintaining fluid balance and nerve function, but they do not directly participate in the transport of carbon dioxide. Their primary function is related to maintaining electrolyte balance within the body.
  • B. Potassium (K+) is crucial for nerve impulses and muscle function. However, it does not play a direct role in carbon dioxide transport. It primarily serves to maintain intracellular fluid balance.
  • D. Chloride ions participate in the chloride shift, which balances charges when bicarbonate ions exit red blood cells. However, chloride itself is not directly responsible for transporting carbon dioxide.

Q111. Equal volume of different gases under same condition of temperature and pressure contain the same number of particles. The above statement is of:

  • A. Avogadro's Law
  • B. Graham's Law
  • C. Dalton's Law
  • D. Hund's Rule

Explanation: The correct answer is Avogadro's Law. This fundamental principle states that equal volumes of gases, at the same temperature and pressure, will contain an equal number of molecules. This is pivotal for understanding gas behavior in chemistry and physics.Graham's Law is concerned with the diffusion and effusion rates of gases, which depend on molecular weight, not volume and particle number.Dalton's Law explains the pressure contributions of individual gases in a mixture, but does not relate to volume and molecule count.Hund's Rule pertains to electron occupation in atomic orbitals, which is irrelevant to gas laws and molecular volume relationships.

Why the other options are wrong
  • B. Graham's Law deals with the rates of diffusion and effusion of gases, indicating that these rates are inversely proportional to the square root of the gas's molecular weight. It is not related to the volume and number of molecules in gases.
  • C. Dalton's Law of Partial Pressures states that in a mixture of non-reacting gases, the total pressure is the sum of the partial pressures of each individual gas. It does not address the relationship between volume and the number of molecules.
  • D. Hund's Rule relates to electron configurations in atomic orbitals, stating that electrons will fill an unoccupied orbital before pairing up. It is not applicable to gases or their volumes.

Q112. Which is the correct statement?

  • A. The average kinetic energy of the molecules depends on the volume in which the gas is enclosed.
  • B. The average kinetic energy of the molecules in the gaseous state is proportional to the pressure.
  • C. The average kinetic energy of the molecules in the gaseous state is proportional to the temperature.
  • D. All of the above

Explanation: Kinetic energy is the energy a substance has because of its molecules being in motion, as a substance absorbs heat its molecules move faster, thereby increasing the substance's kinetic energy.

Why the other options are wrong
  • A. This is incorrect because the average kinetic energy of gas molecules is related to temperature, not the volume. The volume affects the density and pressure of the gas, but not the kinetic energy directly.
  • B. This option is incorrect because the average kinetic energy of gas molecules is determined by the temperature, not the pressure. Pressure can influence the behavior of gases, but only due to changes in temperature.
  • D. This option is incorrect, as only option C is correct. Options A and B incorrectly describe the factors affecting average kinetic energy.

Q113. Hydrogen bonding do not exist in the molecule of:

  • A. Hydrogen gas (H2)
  • B. Proteins
  • C. Carbohydrates
  • D. Ammonia (NH3)

Explanation: Hydrogen bonding is an intermolecular force that occurs when a hydrogen atom is covalently bonded to a highly electronegative atom, such as nitrogen, oxygen, or fluorine. This interaction is absent in hydrogen gas (H2) because it consists of two hydrogen atoms bonded together, without the presence of any electronegative atoms. In contrast, proteins, carbohydrates, and ammonia all have structures that allow for hydrogen bonding due to the presence of nitrogen, oxygen, or hydroxyl groups.

Why the other options are wrong
  • B. Incorrect. Proteins contain peptide bonds (-CONH-) where hydrogen bonding occurs between the carbonyl (C=O) and amide (-NH) groups, stabilizing secondary structures like α-helices and β-sheets.
  • C. Incorrect. Carbohydrates have multiple -OH (hydroxyl) groups which form strong hydrogen bonds, making them highly soluble in water.
  • D. Incorrect. Ammonia has a nitrogen atom with a lone pair and three hydrogen atoms, which allows extensive hydrogen bonding between NH3 molecules.

Q114. Which statement is incorrect about ionization energy?

  • A. Ionization energy depends upon the magnitude of nuclear charge
  • B. Ionization energy depends upon the atomic radius
  • C. Ionization energy depends upon the shielding effect
  • D. Ionization energy does not depend upon the penetration effect of the inner orbital

Explanation: Option D is the correct answer because it incorrectly states that ionization energy does not depend on the penetration effect. In reality, the penetration effect allows inner orbital electrons to be closer to the nucleus, increasing the effective nuclear charge experienced by the outer electrons, and thus increasing ionization energy.Options A, B, and C correctly state the factors affecting ionization energy: nuclear charge, atomic radius, and shielding effect, respectively. Increased nuclear charge strengthens the attraction between electrons and the nucleus, raising ionization energy. A larger atomic radius weakens this attraction, lowering ionization energy. The shielding effect decreases the effective nuclear charge felt by outer electrons, also reducing ionization energy.

Why the other options are wrong
  • A. This statement is correct because a higher nuclear charge attracts electrons more strongly, making it more difficult to remove them, resulting in higher ionization energy.
  • B. This statement is correct because a larger atomic radius means the outermost electrons are farther from the nucleus and experience weaker attraction, making them easier to remove and resulting in lower ionization energy.
  • C. This statement is correct because the shielding effect involves inner electrons partially blocking the attraction between the nucleus and outer electrons, thus lowering ionization energy as these electrons are easier to remove.

Q115. Select the incorrect Statement:

  • A. Molecule may gain an electron to form a molecular anion.
  • B. Molecule may lose an electron to form a molecular cation.
  • C. Molecular cations are less abundant than molecular anions.
  • D. These molecular ions can be formed by passing a high-energy electron beam through a gas.

Explanation: Abundance of cationic molecular ions is due to the ability to stabilize unpaired electrons which makes the formation of cationic molecular ions energetically less demanding. That's why cationic molecular ions are more abundant than anionic ones.

Why the other options are wrong
  • A. This is a correct statement. Molecules can gain electrons to form negatively charged ions, known as anions.
  • B. This is a correct statement. Molecules can lose electrons to form positively charged ions, known as cations.
  • D. This statement is correct. High-energy electron beams can ionize gas molecules, forming both cations and anions.

Q116. Choose the correct Statement:

  • A. The most direct and accurate method for determining atomic masses uses mass spectrometry.
  • B. An indirect but precise method for determining molecular masses is through mass spectrometry.
  • C. Collision between electrons and atoms produces negative ions by the absorption of electrons by atoms or molecules.
  • D. The first significant application of mass spectrometry was demonstrating the detection of isotopes of Argon.

Explanation: Electron Collision. Often, electron collisions with gas molecules result in electron attachment to the molecule, which forms a negative ion.

Why the other options are wrong
  • A. Incorrect. Mass spectrometry is indeed a direct method for measuring mass-to-charge ratios, but this option does not align with the context of the question focused on electron collisions.
  • B. Incorrect. Mass spectrometry is a direct method for measuring the mass-to-charge ratios, not an indirect one.
  • D. Incorrect. The first significant discovery using mass spectrometry was the identification of isotopes of Neon by J.J. Thomson.

Q117. The partition coefficients of Iodine distribution between two immiscible liquids, water and carbon (tetrachloride) is given below:Choose the correct statement about the system:

  • A. Iodine is extracted from CCl4 layer by water
  • B. Iodine is extracted from aqueous layer by CCl4
  • C. Iodine is more soluble in water than CCl4
  • D. The value of K depends on the amount of Iodine added

Explanation: Iodine vastly prefers to dissolve in CCl4 , thus it migrates from the aqueous (H2O) phase into the non-aqueous (CCl4) phase , thus we say that CCl4 extracts the iodine from the aqueous phase.

Why the other options are wrong
  • A. Incorrect. The partition coefficient (K) of 1.17 × 10⁻² indicates that iodine is significantly less soluble in water compared to CCl₄. Iodine, being nonpolar, prefers the nonpolar CCl₄, not water.
  • C. Incorrect. The small value of K (1.17 × 10⁻²) shows that iodine is much more soluble in CCl₄ than in water. A higher K would indicate greater solubility in water.
  • D. Incorrect. The partition coefficient (K) is constant for a given set of conditions and does not depend on the amount of iodine added, assuming the system is not saturated.

Q118. During a experiment, one measured the mass of a mosquito and found it to be 1.20 × 10–5 Kg. The numbers of significant figures in this case are:

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

Explanation: All non zero digits are significant figures and in this case there are 3 significant or non zero digits hence option D is the right choice.

Why the other options are wrong
  • A. This is incorrect. The number 1.20 × 10–5 has only three significant figures: 1, 2, and the zero following the decimal point, which is significant.
  • B. This is incorrect. The number 1.20 × 10–5 has more than one significant figure. The digits 1 and 2, along with the zero, are significant.
  • C. This is incorrect. While the digits 1 and 2 are significant, the zero following the decimal point is also significant, making the total count three.

Q119. The vectors A and B are such that |A + B| = |A – B|, then the angle between the two vectors is:

  • A. 0o
  • B. 90o
  • C. 60o
  • D. 180o

Explanation: Solution is as follows :-

Why the other options are wrong
  • A. If the angle between two vectors is 0 degrees, they are parallel and pointing in the same direction, which would not satisfy the condition |A + B| = |A - B|.
  • C. An angle of 60 degrees would not result in |A + B| being equal to |A - B|, as the dot product would not equate to zero.
  • D. If the angle were 180 degrees, the vectors would be anti-parallel, and |A + B| would not equal |A - B|; instead, it would be |A| + |B| versus |A| - |B|.

Q120. Which statement correctly describes a nucleon?

  • A. Any atomic nucleus
  • B. A radioactive atomic nucleus
  • C. A neutron or a proton
  • D. A neutron proton or an electron

Explanation: A nucleon is either a proton or a neutron, which are the subatomic particles found in the nucleus of an atom. They are held together by the strong nuclear force, which overcomes the repulsive forces between the positively charged protons. This binding is crucial for the stability and mass of the atom. The other options are incorrect: 'Any atomic nucleus' describes a region, not the specific particles; 'A radioactive atomic nucleus' refers to the behavior of the nucleus, not the definition of nucleons; and 'A neutron proton or an electron' includes an electron, which is not part of the nucleus.

Why the other options are wrong
  • A. This is incorrect because 'nucleon' specifically refers to the individual particles within the nucleus, namely protons and neutrons, rather than the nucleus itself.
  • B. This option is incorrect. The term 'radioactive' pertains to the behavior of certain nuclei, not to the definition of a nucleon, which is simply a proton or a neutron.
  • D. Incorrect. While protons and neutrons are nucleons, electrons are not part of the nucleus; they orbit around it.

Q121. The van der waals equation of state for no-ideal gases differs from the ideal gas law in that it accounts for:I) The mass of each molecule of the gas.II) The volume of each molecule of the gas.III) The attractive forces between molecules of the gas

  • A. I, II, and III
  • B. I and II only
  • C. I and III only
  • D. II and III only

Explanation: More significantly, the Van der Waals equation takes into consideration the molecular size and molecular interaction forces (attractive and repulsive forces). Sometimes, it is also referred as the Van der Waals equation of state.

Why the other options are wrong
  • A. This option is incorrect because the van der Waals equation does not account for the mass of each molecule. It focuses on the volume occupied by molecules and the intermolecular forces.
  • B. This option is incorrect as the van der Waals equation does not consider the mass of molecules but rather their volume and intermolecular forces.
  • C. This option is incorrect because the van der Waals equation accounts for the volume of each molecule and the attractive forces between them, not the mass of each molecule.

Q122. The statement that heat cannot spontaneously flow from a colder to a hotter body is a result of:

  • A. Henry's law
  • B. The first law of thermodynamics
  • C. The second law of thermodynamics
  • D. The third law of thermodynamics

Explanation: 2nd law of thermodynamics expresses a fundamental and simple truth about the universe, it states that heat cannot flow from colder body to hotter body.

Why the other options are wrong
  • A. Henry's law pertains to the behavior of gases dissolved in liquids, concerning their concentration and partial pressure. It does not relate to the flow of heat between bodies, making this an incorrect option.
  • B. The first law of thermodynamics, also known as the law of energy conservation, states that energy cannot be created or destroyed, only transformed. It does not address the direction of heat flow, so it is an incorrect option.
  • D. The third law of thermodynamics concerns the behavior of systems as they approach absolute zero, stating that entropy approaches a minimum value. It does not address heat flow between bodies, thus it is an incorrect option.

Q123. Ruther ford‘s scattering experiment demonstrates:

  • A. The existence of X-rays
  • B. The existence of negative particles
  • C. The mass to charge ratio of the electron
  • D. The nuclear model of the atom

Explanation: Rutherford's gold foil experiment was a pivotal moment in atomic physics. It demonstrated that the atom consists of a tiny, dense nucleus containing most of its mass, which caused the deflection of some alpha particles. This experiment refuted the plum pudding model and led to the nuclear model of the atom, where electrons orbit a central nucleus. The other options are incorrect because they relate to different discoveries: X-rays were discovered by Roentgen, J.J. Thomson demonstrated the existence of electrons, and he also found the mass to charge ratio of the electron.

Why the other options are wrong
  • A. This option is incorrect. The existence of X-rays was demonstrated by Wilhelm Roentgen, not Rutherford.
  • B. This option is incorrect. The existence of electrons, which are negative particles, was demonstrated by J.J. Thomson, not Rutherford.
  • C. This option is incorrect. J.J. Thomson's experiments were responsible for discovering the mass to charge ratio of the electron.

Q124. Which is an incorrect statement?

  • A. The ionic bonds are non-directional in character
  • B. The crystals of covalent compounds are made up of molecules
  • C. The covalent bonds are rigid and non-directional
  • D. Ionic compounds have high melting points and boiling points

Explanation: Covalent bonds are directional because they involve specific orientations of shared electron pairs, leading to definite molecular shapes. This makes Option C, which claims covalent bonds are non-directional, incorrect. Option A is correct since ionic bonds are non-directional due to uniform electrostatic forces. Option B is correct as covalent compounds are indeed made of molecules. Option D is correct because ionic compounds have high melting and boiling points due to strong ionic attractions.

Why the other options are wrong
  • A. Ionic bonds are non-directional because the electrostatic forces act uniformly in all directions between ions. This makes the statement correct, not the incorrect statement being asked for in the question.
  • B. Covalent compounds are composed of atoms bonded together by covalent bonds, forming distinct molecules. This statement is correct, as covalent compounds are molecular in nature, making it not the incorrect statement in the question.
  • D. Ionic compounds have high melting and boiling points due to the strong electrostatic attractions between oppositely charged ions. This statement is correct, not the incorrect statement being asked for in the question.

Q125. In which compound the bond angle is maximum?

  • A. Methane
  • B. Beryllium chloride
  • C. Ammonia
  • D. Boron trifluoride

Explanation: BeCl2 has bond angle of 180 °

Why the other options are wrong
  • A. Bond angle of methane is 109.5 degrees. So, it is an incorrect option.
  • C. Bond angle of ammonia is 107 degrees. So, it is an incorrect option.
  • D. Bond angle of this compound is 120 degrees. So, it is an incorrect option.

Q126. Which is not used in calculating the lattice energy of crystalline solids?

  • A. Haber process
  • B. Born Haber cycle
  • C. Hess‘s law
  • D. Enthalpy changes

Explanation: The answer is Haber process because it is the process of formation of ammonia from nitrogen and hydrogen under high pressure.

Why the other options are wrong
  • B. Born haber cycle is used to calculate the lattice energy so it is an incorrect option.
  • C. Hess’s law is also used in calculating the lattice energy so it is an incorrect option.
  • D. It is also an incorrect option as enthalpy changes are used in calculating the lattice energy.

Q127. The first artificial radioactive substance was made by bombarding aluminum 15Al27, with fix-particle. This produced an unstable isotope of phosphorus, 15P30, What was the byproduct of this reaction?

  • A. An α-particle
  • B. A β-particle
  • C. A γ-ray
  • D. A neutron

Explanation: It is not 27Al15, it is 27Al13Thus the answer is a neutron.

Why the other options are wrong
  • A. As per the explanation, this option is incorrect.It is not 27 Al15, it is 27 Al13. Thus, the answer is a neutron. The by product of the reaction where aluminum-27 is bombarded with alpha particles (helium-4 nuclei, to produce phosphorus-30) is a neutron.In this reaction, an alpha particle is bombarded onto aluminum-27, resulting in the formation of phosphorus-30 and a neutron as a byproduct.
  • B. As per the explanation, this option is incorrect.It is not 27 Al15, it is 27 Al13. Thus, the answer is a neutron. The by product of the reaction where aluminum-27 is bombarded with alpha particles (helium-4 nuclei), is a neutron.In this reaction, an alpha particle is bombarded onto aluminum-27, resulting in the formation of phosphorus-30 and a neutron as a byproduct.
  • C. As per the explanation, this option is incorrect.It is not 27 Al15, it is 27 Al13. Thus, the answer is a neutron. The by product of the reaction where aluminum-27 is bombarded with alpha particles (helium-4 nuclei) to produce phosphorus-30 is a neutron.In this reaction, an alpha particle is bombarded onto aluminum-27, forming phosphorus-30 and a neutron as a byproduct.

Q128. Which species has no net charge?

  • A. An α-particle
  • B. An electron
  • C. A proton
  • D. A neutrino

Explanation: The correct answer is a neutrino. Neutrinos are neutral particles, meaning they have no electric charge. They are part of the lepton family in the Standard Model of particle physics and interact only via the weak nuclear force and gravity. This lack of charge allows them to pass through matter nearly undetected, as they do not interact with electromagnetic forces.In contrast, an α-particle, electron, and proton all have net charges. An α-particle has a charge of +2, an electron has a charge of -1, and a proton has a charge of +1. Thus, none of these particles are neutral.

Why the other options are wrong
  • A. An α-particle is composed of 2 protons and 2 neutrons, making it identical to a helium nucleus. It has a net positive charge of +2 due to the protons, and is thus not neutral. This makes it an incorrect option.
  • B. Electrons are fundamental particles with a negative charge of -1. They are not neutral since they carry a charge, making this option incorrect.
  • C. Protons have a positive charge of +1. As they carry a charge, they do not have a net charge of zero, making this an incorrect option.

Q129. Which of the following compound is assigned the octane number of 100?

  • A. n-heptane
  • B. n-octane
  • C. 2,3,3-trimethylpentane
  • D. 2,2,4-trimethylpentane

Explanation: The correct answer is 2,2,4-trimethylpentane, also known as isooctane. It is assigned an octane number of 100 because it has excellent knock resistance in engines. This compound serves as a standard reference point in the octane rating scale, indicating that it can withstand high compression without detonating prematurely. In contrast, n-heptane, with an octane number of 0, has very poor resistance to knocking. n-Octane has an even lower resistance, indicated by its negative octane number. 2,3,3-Trimethylpentane, while having a high knock resistance, does not serve as the standard reference and has a different octane rating.

Why the other options are wrong
  • A. n-Heptane is used as a reference fuel with an octane number of 0, indicating low resistance to knocking. Thus, it is incorrect.
  • B. n-Octane has a negative octane number, meaning it has poor knock resistance. Therefore, it is incorrect.
  • C. 2,3,3-Trimethylpentane has a high octane rating but not exactly 100. It is often used as a gasoline component but doesn't serve as the reference standard.

Q130. The major product of acid catalysed dehydration of 3- pentanol is:

  • A. 1-Pentene
  • B. 3-Pentene
  • C. 2-Methylbutane
  • D. 3-Methylbutane

Explanation: The major product is 2-pentene because it is the most stable alkene formed after carbocation rearrangement and follows Zaitsev's rule. The reaction proceeds through an E1 mechanism involving a carbocation intermediate and rearrangement.

Why the other options are wrong
  • A. 1-Pentene: This would be the product if elimination occurred at the primary carbon, but this is less favored due to the instability of the primary carbocation and the tendency to form more substituted alkenes.
  • C. 2-Methylbutane is an alkane and not an alkene. Dehydration of alcohols results in the formation of alkenes, not alkanes.
  • D. 3-Methylbutane is incorrect because it is an alkane and does not reflect the dehydration process which produces alkenes, not alkanes.

Q131. Which of the following compound will react most readily with bromine in CCl4?

  • A. 1-pentene
  • B. 2-pentene
  • C. 2-Methyl-1-butene
  • D. 3-Methyl-1-butene

Explanation: The reaction of alkenes with bromine proceeds through the formation of a carbocation intermediate. The stability of these carbocations is determined by the number of alkyl substituents; more substituents lead to greater stability. Among the given options, 3-methyl-1-butene forms the most stable carbocation due to its tertiary structure, resulting in the fastest reaction with bromine in CCl4. In contrast, 1-pentene forms the least stable primary carbocation, leading to the slowest reaction, while both 2-pentene and 2-methyl-1-butene form secondary carbocations that are more stable than that of 1-pentene but less stable than that of 3-methyl-1-butene, making them less reactive than the correct answer.

Why the other options are wrong
  • A. 1-Pentene is a straight-chain alkene that can react with bromine. However, the carbocation formed from its reaction is less stable due to fewer alkyl substituents, leading to a slower reaction rate.
  • B. 2-Pentene is also a straight-chain alkene. It forms a more stable carbocation than 1-pentene due to having one more alkyl group, but it is still less stable than the carbocation formed from 3-methyl-1-butene.
  • C. 2-Methyl-1-butene is a branched alkene that generates a more stable carbocation compared to straight-chain alkenes. However, its stability is still lower than that of 3-methyl-1-butene, making its reaction with bromine less favorable than the correct answer.

Q132. The half life of 22Na is 2.6 years. If X grams of this sodium isotope are initially present, how much is left after 13 years.

  • A. X/32
  • B. X/13
  • C. X/8
  • D. X/5

Explanation: Half life is 2.6 yearsInitially x grams of sodium isotope were present After 13 years which is 13/2.6 = 5 years Let the amount of sodium left is y gramPutting formulaN=N°(½)n Here y = x(½)5 y = x/32

Why the other options are wrong
  • B. This is incorrect. This option incorrectly assumes a linear rather than exponential decay over 13 years. Half-life calculations involve exponential decay.
  • C. This is incorrect. This option may result from a miscalculation of the number of half-lives or an incorrect application of the decay formula.
  • D. This is incorrect. This option incorrectly divides the initial quantity by the number of half-lives without considering the exponential nature of half-life decay.

Q133. Monochromatic light passes through two parallel slits in a secreen and falls on a place of film. The patteren produced is an example of:

  • A. Refraction and diffraction
  • B. Interference and reflection
  • C. Interference and diffraction
  • D. Diffraction and polarization

Explanation: When monochromatic light passing through two parallel slit and falls on a screen, the pattern produced is due to interference and diffraction.

Why the other options are wrong
  • A. Refraction involves a change in direction when light travels between media, while diffraction is about light bending around obstacles. This option doesn't fully describe the pattern from two slits.
  • B. Reflection involves light bouncing off surfaces, not passing through slits. Interference occurs when waves overlap, but reflection is unrelated to this slit experiment.
  • D. Polarization describes wave orientation, irrelevant in this context, while diffraction is relevant. This option doesn't fully explain the pattern produced.

Q134. Sodium chloride crystal structure is:

  • A. Hexagonal
  • B. Body centered cubic
  • C. Face centered cubic
  • D. Tetragonal

Explanation: Explanation diagram is given below.

Why the other options are wrong
  • A. Hexagonal structures are common in some metals and minerals but not in sodium chloride. The sodium chloride crystal structure is face-centered cubic, not hexagonal. Therefore, this is an incorrect option.
  • B. Body-centered cubic structures are found in some metals, like iron at certain temperatures. However, sodium chloride has a face-centered cubic structure, not body-centered cubic. Thus, this is an incorrect option.
  • D. Tetragonal crystal structures are characterized by one axis being longer or shorter than the other two. Sodium chloride does not have this arrangement; instead, it has a face-centered cubic structure. Therefore, this is an incorrect option.

Q135. An acid is a substance which accepts:

  • A. An electron pair
  • B. A proton
  • C. An electron
  • D. Pair of protons

Explanation: The correct answer is that an acid is a substance which accepts an electron pair, according to the Lewis concept. This concept broadens the traditional definition of acids beyond the Bronsted-Lowry theory, which focuses on proton donation. Thus, Option A is correct. Option B is incorrect as it describes the action of acids in the Bronsted-Lowry concept, which involves donating, not accepting, a proton. Option C is incorrect because it misinterprets the Lewis concept, emphasizing that acids accept electron pairs instead of single electrons. Option D is incorrect as no accepted theory or concept describes acids as accepting pairs of protons; the focus remains on single proton donation in the Bronsted-Lowry framework.

Why the other options are wrong
  • B. The Bronsted-Lowry concept defines an acid as a substance that donates a proton, not accepts one. Therefore, this option does not align with the question's premise.
  • C. The Lewis concept involves the acceptance of an electron pair, not a single electron. This distinction is crucial as it affects the understanding of chemical interactions involving acids.
  • D. No scientific theory defines an acid as accepting a pair of protons. The Bronsted-Lowry theory specifically describes acids as donating a single proton.

Q136. Carbon-14 is used in carbon dating. Which of the following species has both same number of neutrons and same number of electrons as in atom of c-14?

  • A. 14N
  • B. 14N+
  • C. 12C
  • D. 13C

Explanation: Carbon-14 has 6 protons, 6 electrons and 8 neutrons. Nitrogen-14 has 7 protons, 7 electrons, and 7 neutrons. The mass number of 14, is the total of neutrons and protons, in a nucleus.

Why the other options are wrong
  • A. The notation '14N' represents a nitrogen isotope with an atomic mass of 14 and an atomic number of 7. It has 7 protons and 7 electrons, making it neutral. It also has 7 neutrons, which is the same number of neutrons as in C-14. Since it is neutral, it has 7 electrons, which does not match the 6 electrons in C-14.
  • C. The notation '12C' represents a carbon isotope with an atomic mass of 12 and an atomic number of 6. It has 6 protons, 6 electrons, and 6 neutrons, which do not match the number of neutrons in C-14 (8 neutrons).
  • D. The notation '13C' represents a carbon isotope with an atomic mass of 13 and an atomic number of 6. It has 6 protons, 6 electrons, and 7 neutrons, which do not match the number of neutrons in C-14 (8 neutrons).

Q137. Reduction of acetaldehyde with H2/Ni gives:

  • A. Ethanol
  • B. Ethanoic acid
  • C. Ethane
  • D. Ethylene

Explanation: H2/Ni are strong reducing agents which reduces aldehydes to primary alcohols and ketones to secondary alcohols.

Why the other options are wrong
  • B. Reduction of acetaldehyde with H₂/Ni does not produce ethanoic acid. This reaction forms a primary alcohol, not a carboxylic acid.
  • C. Reduction of acetaldehyde with H₂/Ni forms a primary alcohol, not an alkane like ethane.
  • D. Reduction of acetaldehyde with H₂/Ni does not produce ethylene. This reaction results in a primary alcohol, not an alkene.

Q138. Which of the following compounds will give a positive test with Fehling‘s solution?

  • A. Acetone
  • B. Ethyl acetate
  • C. Formaldehyde
  • D. Acetic acid

Explanation: Although both aldehydes and ketones contain the carbonyl functional group (-C=O), only aldehydes give a positive test (formation of an orange to brick-red precipitate of copper(I) oxide) with Fehling's solution.

Why the other options are wrong
  • A. Acetone is a ketone, and Fehling's solution does not react with ketones. The test is specific to aldehydes, so this is an incorrect option.
  • B. Ethyl acetate is an ester, which does not have an aldehyde group, so it will not give a positive test with Fehling's solution. This is an incorrect option.
  • D. Acetic acid is a carboxylic acid, not an aldehyde. Therefore, it does not react with Fehling's solution. This is an incorrect option.

Q139. Choose the compound in which hydrogen bonding is not possible:

  • A. H2O
  • B. HCl
  • C. CH3COOH
  • D. CH3OCH3

Explanation: Due to the presence of methyl groups that bounds to oxygen there is less tendency of hydrogen bonding in ethers.Also, it does not have hydrogen attached to oxygen, so it cannot form hydrogen bonds with itself.The carboxylic acid, alcohol and water being polar show H-bonding. Option A is correct.

Why the other options are wrong
  • A. Water molecules form hydrogen bonds as each hydrogen atom is bonded to a highly electronegative oxygen atom, which has lone pairs available for bonding. Therefore, hydrogen bonding is possible. This option is incorrect.
  • B. Hydrogen chloride does not typically form hydrogen bonds because the hydrogen is not bonded to a highly electronegative atom with available lone pairs like O, N, or F. However, hydrogen bonds are not as common in this compound, making this an incorrect option for lacking hydrogen bonding.
  • C. Acetic acid can form hydrogen bonds due to the presence of a hydroxyl group (OH) where hydrogen is bonded to an electronegative oxygen atom. This allows for hydrogen bonding with itself and other molecules. This option is incorrect.

Q140. The temperature required for vernalization is approximately:

  • A. 2˚C
  • B. 3˚C
  • C. 4˚C
  • D. 10˚C

Explanation: Vernalization requires an exposure to temperatures between 0–6 °C for several months.

Why the other options are wrong
  • A. This option is incorrect because while 2˚C may be within the range for some plants, the average temperature required for vernalization is closer to 4˚C.
  • B. This option is incorrect as the typical temperature needed for vernalization is approximately 4˚C, which is the midpoint of the optimal range.
  • D. This option is incorrect because 10˚C is too warm for vernalization. The process typically occurs at much lower temperatures, around 0-6˚C.

Q141. Which one of the following does not exist?

  • A. HBO2
  • B. HFO2
  • C. H3PO3
  • D. HBrO2

Explanation: HBrO2(aq) is bromous acid and HIO2(aq) is iodous acid. Like many of the oxyacids, the molecules of HBrO2 (hydrogen bromite) and HIO2 (hydrogen iodide) are unlikely to exist in nature as they would likely decompose into oxides and water vapour when trying to isolate them from their respective acid solutions.

Why the other options are wrong
  • A. HBO2 (Metaboric Acid) is a known compound. Boron can form stable bonds with both hydrogen and oxygen, making this compound possible.
  • C. H3PO3 (Phosphorous Acid) is a stable compound and one of the common oxoacids of phosphorus, known for its ability to form stable structures.
  • D. HBrO2 (Bromous Acid) is less stable than other oxyacids but can exist under specific conditions, as bromine can form bonds with oxygen atoms.

Q142. Select the strongest acidThe pKa values are given:

  • A. HI, pKa=-10
  • B. HCN, pKa=9.4
  • C. H2SO4, pKa = 1.8
  • D. HNO3, pKa = 3.0

Explanation: The strength of an acid is determined by its ability to donate protons, which is quantified by its pKa value. A lower pKa signifies a stronger acid. Hydroiodic acid (HI) with a pKa around -10 is extremely strong, far exceeding the strength of sulfuric acid (H2SO4) with a pKa of 1.8. Hydrocyanic acid (HCN) has a high pKa of 9.4, indicating it is a weak acid. Nitric acid (HNO3) has a pKa of 3.0, making it stronger than HCN but weaker than both H2SO4 and HI. Therefore, considering the correct pKa values, HI is the strongest acid.

Why the other options are wrong
  • B. HCN (pKa = 9.4): Hydrocyanic acid is a weak acid. Its relatively high pKa value indicates poor proton donation capability, making it much weaker than the other options.
  • C. H₂SO₄ (pKa = 1.8): Sulfuric acid is a strong acid and is often considered the benchmark for strong acids, but not as strong as HI when the correct pKa is considered.
  • D. HNO₃ (pKa = 3.0): Nitric acid is a strong acid, but its pKa value is higher than that of sulfuric acid, indicating it is less strong than H2SO4 and much weaker than HI.

Q143. An electron in a hydrogen atom makes a transition from an energy level with energy E1, to one with energy E2 and simultaneously emits a photon. The wavelength of the emitted photon is:

  • A. hc/(E1 – E2)
  • B. h/(E1 – E2)
  • C. h/c(E1 – E2)
  • D. (E1 – E2)/hc

Explanation: But as per ptb, the energy change is given by ∆E=E2-E1∆E=hv∆E=hc/λ E2- E1=hc/λ λ =hc/E2- E1 Ans

Why the other options are wrong
  • B. Incorrect. This formula omits the speed of light (c), which is necessary for the correct units of wavelength.
  • C. Incorrect. The speed of light (c) is incorrectly placed in the denominator. It should be in the numerator.
  • D. Incorrect. This formula incorrectly places the energy difference in the numerator. Wavelength should be inversely proportional to the energy difference.

Q144. The electric field between the plates of an isolated air-spaced parallel- plate capacitor is E. What is the field between the plates after immersing the capacitor in a liquid of relative permitivity 10?

  • A. E√10
  • B. E/√10
  • C. 10E
  • D. E/10

Explanation: The relationship between the electric field in the absence of the dielectric (E0) and the electric field with the dielectric (E) is given by:E = E0 / εrwhere εr is the relative permittivity of the medium.In this case, the relative permittivity of the liquid is given as 10. Therefore, the fiel used between the plates after immersing the capacitor in the liquid is:E' = E / εr = E / 10So, the correct answer is option 4E / 10SO, ELECTRIC FIELD WILL DECREASE BY A FACTOR 10.

Why the other options are wrong
  • A. This is incorrect. Introducing a dielectric reduces the electric field; it does not increase it.
  • B. This is incorrect. The formula for the electric field with a dielectric involves dividing by the relative permittivity, not its square root.
  • C. This is incorrect. The electric field is reduced by the dielectric, not increased by a factor of 10.

Q145. A current of 20.0A flows through a battery with an e.m.f of 6.20 V. If the internal resistance of the battery is 0.01, what is the terminal voltage?

  • A. 6.40V
  • B. 31.0V
  • C. 1.24V
  • D. 6.00V

Explanation: V = e.m.f - (I * Rinternal)where:V is the terminal voltage,e.m.f is the electromotive force (voltage) of the battery,I is the current flowing through the battery, andR_internal is the internal resistance of the battery.In this case, the e.m.f is given as 6.20 V, the current is 20.0 A, and the internal resistance is 0.01 Ω. Plugging these values into the formula, we get:V = 6.20 V - (20.0 A * 0.01 Ω)V = 6.20 V - 0.20 VV = 6.00 V

Why the other options are wrong
  • A. This option is incorrect. The error likely comes from incorrect subtraction or multiplication in the formula V = e.m.f - (I * Rinternal).
  • B. This option is incorrect. It's significantly higher than the given e.m.f, indicating a misunderstanding of how internal resistance affects terminal voltage.
  • C. This option is incorrect. It's lower than expected, possibly due to misapplying the formula or incorrect calculations.

Q146. Which derived unit below is equivalent to the SI unit for magnetic field strength, the tesla, T?

  • A. N m / A
  • B. N A / m
  • C. N / A m
  • D. A m / N

Explanation: Force(F) = B(magnetic field strength) x I (current) x L (length / distance)hence , the SI units for each of the above mentioned properties areNewton (N) = B x ampere (A) x Meter (M)Rearrange to make B the subject and get its SI unit.

Why the other options are wrong
  • A. This option is incorrect. The unit N m / A is not equivalent to tesla. Instead, tesla is defined based on the unit of magnetic flux density, which is Weber per square meter (Wb/m2).
  • B. This option is incorrect. The unit N A / m does not correspond to tesla. Remember, tesla is a measurement of magnetic flux density, defined as Weber per square meter (Wb/m2).
  • D. This option is incorrect. The unit A m / N is not equivalent to tesla. The tesla is defined as Weber per square meter (Wb/m2), which corresponds to N / A m when considering its relationship with force and current.

Q147. A wire of resistance 3.0 Ω is stretched to twice its original length. The resistance of the new wire will be:

  • A. 1.5 Ω
  • B. 3.0 Ω
  • C. 6.0 Ω
  • D. 12.0 Ω

Explanation: R = PL/A where p is density, L is length and A is area.Resistance R = ρℓ / Aℓ’ = 2 ℓ ⇒ A’ = A / 2R’ = ρ [2 ℓ / (A / 2)] = 3R = 3 × 4Ω = 12Ω

Why the other options are wrong
  • A. This option is incorrect. Stretching the wire increases its resistance, not decreases it.
  • B. This option is incorrect. The resistance does not remain the same when the length of the wire is changed.
  • C. This option is incorrect. The resistance increases by a factor of four, not two.

Q148. A wire of resistance 4 is bent into a circle. The resistance between the ends of a diameter of the circle is:

  • A. 4Ω
  • B. 1 Ω
  • C. 1/4 Ω
  • D. 1/16 Ω

Explanation: When a wire of resistance 4R is bent in the form of circle, then the resistance of each segment across the diameter becomes 2R.Equivalent resistance between A and B: +1/Rb (in parallel combination)∴ 1/RAB = 1/(2R) +1/(2R) 1/RAB = 2/(2R) ⟹ RAB=RHere is the link from where you understand this MCQ:

Why the other options are wrong
  • A. This option is incorrect.
  • C. This option is incorrect.
  • D. This option is incorrect.

Q149. The state of thermal equllibrium between two systems is determined by equality of:

  • A. Pressure
  • B. Volume
  • C. Temperature
  • D. Mass

Explanation: Thermal equilibrium between two systems is determined by the equality of temperature, as stated by the Zeroth Law of Thermodynamics. This law implies that if no heat flows between the two systems, they are at the same temperature. Pressure and volume relate to mechanical and volumetric properties, respectively, but do not define thermal equilibrium. Mass influences heat capacity but is not a determining factor for thermal equilibrium.

Why the other options are wrong
  • A. Pressure is related to mechanical equilibrium, not thermal equilibrium. It ensures that no net forces act on a system, but it does not determine thermal equilibrium.
  • B. Volume can affect the capacity of a system to store heat, but it does not directly determine thermal equilibrium. Thermal equilibrium is not dependent on the volume being equal.
  • D. Mass influences the amount of heat a system can absorb or release, but it does not determine thermal equilibrium. Equal mass does not imply thermal equilibrium.

Q150. In the direction indicated by an electric field line:

  • A. The electric field strength must increase
  • B. The electric field strength must decrease
  • C. The potential must decrease
  • D. None of these

Explanation: The correct answer is that the potential must decrease (Option C). Electric field lines are oriented from higher to lower electric potential, indicating that potential decreases along the direction of the field. Options A and B are incorrect because electric field lines do not provide information about the magnitude of the electric field; thus, strength may vary in any direction. Option D is incorrect because Option C accurately describes the relationship between electric field lines and potential.

Why the other options are wrong
  • A. This option suggests the electric field strength always increases along the field lines. However, electric field lines show direction, not magnitude. Thus, the strength can vary.
  • B. This option proposes the electric field strength always decreases along the field lines. Like the previous option, field lines indicate direction without specifying strength changes, which can fluctuate.
  • D. This option is incorrect as one of the given statements accurately describes the behavior of electric field lines regarding potential change.

Q151. Which of the following physical phenomena connot be described only by the wave theory of the electromagnetic radiation?

  • A. Diffraction
  • B. Interference
  • C. Photoelectric Effect
  • D. Polarization

Explanation: The correct answer is the Photoelectric Effect. This phenomenon cannot be adequately described by the wave theory of light alone because it demonstrates that light can behave as a stream of particles (photons), with each photon having a discrete energy that can be transferred to electrons. This is in contrast to wave-based phenomena like diffraction, interference, and polarization, which can be fully explained by the wave theory of electromagnetic radiation.

Why the other options are wrong
  • A. Diffraction involves the bending and spreading of waves when they encounter an obstacle or opening. This phenomenon is well-explained by the wave theory of electromagnetic radiation, as it results in patterns of constructive and destructive interference that align with the wave nature of light.
  • B. Interference is a result of the superposition of waves from coherent sources. This phenomenon, demonstrated in Young's Double-Slit Experiment, is a classic example of the wave nature of light, where overlapping waves produce regions of reinforcement and cancellation.
  • D. Polarization is the process by which the oscillations of light waves are restricted to a single plane. This phenomenon indicates the transverse nature of light waves and is consistent with the wave theory of electromagnetic radiation, as it does not require a particle-like description.

Q152. Which of the following is the same unit as the farad?

  • A. Ωs
  • B. Ωs–1
  • C. Ω–1s
  • D. Ω–1 s–1

Explanation: Farad is defined as charges held per unit of volt across the capacitor. Charges are current x time. So farad is the current x time over volt, or time over ohm.

Why the other options are wrong
  • A. This option is incorrect. The unit 'ohm second' (Ωs) represents resistance multiplied by time, which does not equate to capacitance. In electrical terms, this would instead relate to energy dissipation or other time-dependent resistance phenomena, not capacitance.
  • B. This option is incorrect. The unit 'ohm per second' (Ωs–1) represents resistance divided by time, which is not equivalent to capacitance. This unit does not align with the dimensional analysis required for capacitance.
  • D. This option is incorrect. The unit 'per ohm per second' (Ω–1 s–1) represents conductance per time, not capacitance. This unit is associated with a rate of change of conductance rather than the ability to store charge.

Q153. The gravitational field strength on the surface of the Earth is g. The gravitational field strength on the surface of a planet of twice the radius and the same density is:

  • A. 4g
  • B. 2g
  • C. g
  • D. g/4

Explanation: The unit "per ohm second" (Ω⁻¹s) is indeed equivalent to the unit "farad" (F), which is the SI unit of capacitance. Both units represent different aspects of electrical properties. In the context of capacitance, the farad (F) measures the ability of a capacitor to store an electric charge for a given voltage. It's defined as one coulomb of charge per volt of potential difference.On the other hand, "per ohm second" (Ω⁻¹s) represents the unit of electrical conductance multiplied by time. Conductance is the reciprocal of resistance (measured in ohms), and when multiplied by time (seconds), it becomes equivalent to capacitance (farads).In mathematical terms:1 F = 1 Ω⁻¹sThis relationship highlights the interconnectedness of various electrical properties and units.Now, the gravitational field strength (g') on the surface of the new planet will be determined by the following equation: g' = G * (M' / R'²) where: G is the gravitational constant (a universal constant, approximately 6.674 × 10⁻¹¹ N(m/kg)²), M' is the mass of the planet (which is 8 times the mass of the Earth), R' is the radius of the planet (twice the radius of the Earth). Since the mass and radius are both larger by a factor of 8 and 2, respectively, the gravitational field strength on the surface of the new planet (g') will be: g' = 8g/4 = 2g Therefore, the gravitational field strength on the surface of a planet with twice the radius and the same density as the Earth will be two times the gravitational field strength on the surface of the Earth (2g).Refer to this video for better understanding:

Why the other options are wrong
  • A. This is incorrect. The mass increases by a factor of 8, but the radius squared increases by a factor of 4, reducing the effect.
  • C. Incorrect. If the radius changes while keeping the density constant, the gravitational field strength must change too.
  • D. This is incorrect. The radius affects the gravitational field strength, but considering mass is also crucial.

Q154. Which experimental teachnique reduces the systematic error of the quantity being investigated?

  • A. Adjusting an ammeter to remove its zero error before measuring a current
  • B. Measuring several internodal distances on a standing wave to find the mean internodal distance
  • C. Measuring the diameter of a wire repeatedly and calculating the average
  • D. Timing a large number of oscillations to find a period

Explanation: Systematic error means that measurements of the same thing will vary in predictable ways. Systematic errors in experimental observations usually come from the instruments which are used in measuring. So, zero error is recognized as the systematic error. Thus adjusting an instrument to remove its zero error before measuring something is the best experimental technique to reduce the systematic error of the quantity being investigated.

Why the other options are wrong
  • B. This method is used to improve precision by averaging multiple measurements, but it doesn't specifically target systematic errors, which are consistent and will affect all measurements in the same way.
  • C. Similar to Option B, this approach reduces random errors by averaging but doesn't address systematic errors, which would affect all measurements consistently.
  • D. This method is used to reduce random errors by increasing the data set size, but it does not specifically reduce systematic errors which might be affecting the timing consistently.

Q155. A basketball is thrown upward along a parabollic path. What is the ball‘s acceleration at its highest point?

  • A. 0
  • B. 1/2g, horizontally
  • C. g, upward
  • D. g, downward

Explanation: At the highest point of travel, the vertical velocity is zero but since the force of gravity still is acting on it, the acceleration is equal to the acceleration due to gravity. Its value is 9.8 m/s2 at locations near the equator.

Why the other options are wrong
  • A. This option is incorrect. Although the vertical velocity is zero at the highest point, the acceleration is not zero because gravity is still acting on the basketball.
  • B. This option is incorrect. There is no horizontal acceleration; the only acceleration acting on the basketball is the constant gravitational acceleration which is vertical.
  • C. This option is incorrect. While the basketball is moving upwards before reaching the highest point, the acceleration due to gravity always acts downward, not upward.

Q156. Conversion of alternating current to direct current is called:

  • A. Amplification
  • B. Rectification
  • C. Modulation
  • D. Both B & C

Explanation: A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC). Option B is correct as Rectification is the process of converting alternating current (AC) to direct current (DC). This is typically done using a device called a rectifier, which allows current to flow in only one direction.

Why the other options are wrong
  • A. This option is incorrect. Amplification increases the strength of an electrical signal without changing its type. It does not involve converting AC to DC.
  • C. This option is incorrect. Modulation involves altering a signal to transmit information, not converting AC to DC.
  • D. This option is incorrect. Only rectification is relevant to converting AC to DC. Modulation is not involved in this process.

Q157. Operational amplifiers can amplify:

  • A. AC only
  • B. DC only
  • C. Both AC and DC
  • D. None of them

Explanation: An operational amplifier is a very high gain voltage amplifier. It is used to amplify the signals by increasing its magnitude and can amplify both DC and AC signals.

Why the other options are wrong
  • A. Operational amplifiers are not limited to AC signals. They are capable of amplifying both AC and DC signals, so this option is incorrect.
  • B. Operational amplifiers can handle more than just DC signals. They amplify both AC and DC signals, making this option incorrect.
  • D. This option is incorrect because operational amplifiers can amplify both AC and DC signals.

Q158. A medical lab has a 16g of sample of radioactive isotopes. After 6 hours it was found that 12g of a sample have decayed. The half life of the isotope is:

  • A. 12 hours
  • B. 6 hours
  • C. 2 hours
  • D. 3 hours

Explanation: Original amount = 16gDecayed amount = 12gradioactive isotope left after 6 hours is, 16 g - 12 g = 4 gUse N = No/2nWhere N = 4g , No = 16gWithin 6 hours, the original amount of 16g was first halved to 8g and then it was halved to 4g16g ---3 hrs---- 8g ----3 hrs--- 4gThus the half-life of the sample is 3 hrs.

Why the other options are wrong
  • A. This is incorrect because in 12 hours, the original amount would reduce to less than 4g, given a half-life of 12 hours.
  • B. This is incorrect because in 6 hours, the original amount reduced to 4g, indicating the half-life must be shorter than 6 hours.
  • C. This is incorrect because if the half-life were 2 hours, the remaining amount after 6 hours would be less than 4g.

Q159. The sound waves and light waves cannot be both:

  • A. Polarized
  • B. Refracted
  • C. Reflected
  • D. Diffracted

Explanation: Light waves can be polarised but sound waves cannot.

Why the other options are wrong
  • B. Both sound and light waves can be refracted. This happens when they pass through different media, causing a change in speed and direction. For example, light refracts when moving from air to water, and sound refracts when moving through layers of different temperatures in the atmosphere.
  • C. Reflection occurs for both sound and light waves when they encounter a surface or boundary. Light reflects off mirrors, and sound reflects off walls or mountains, making both capable of reflection.
  • D. Diffraction is the bending and spreading of waves when they pass through an opening or around obstacles. Both sound and light can undergo diffraction, although the effects are more noticeable for sound due to its longer wavelengths.

Q160. Diffraction is the name given to the:

  • A. Addition of two coherent waves to produce a stationary wave pattern.
  • B. Bending and spreading of waves around an obstacle or through an opening.
  • C. Change of direction when waves cross the boundary between one medium and another.
  • D. Splitting of white light into its constituent colors.

Explanation: Diffraction is the spreading of waves around obstacles.

Why the other options are wrong
  • A. This describes interference, specifically the formation of standing waves, not diffraction. In interference, waves overlap to form new wave patterns.
  • C. This describes refraction, where waves bend due to a change in speed as they pass from one medium to another, not diffraction.
  • D. This describes dispersion, which occurs when different colors of light are refracted by different amounts, not diffraction.

Q161. Two forces having magnitudes 3.5N and 5.5N are acting on a body. Which one of the following cannot be the resultant of their possible sum?

  • A. 1.5 N
  • B. 2.5 N
  • C. 4.5 N
  • D. 6.5 N

Explanation: 1.5 N cannot be the resultant of their possible sum because neither the subtraction, nor the addition of both values gives 1.5. The value of resultant can only be subtracted value or additional value which will either be 5.5-3.5= 2 whereas additional value = 5.5+3.5 = 9 so the resultant can range from 2 till 9.

Why the other options are wrong
  • B. Option B is incorrect. 2.5N lies within the possible range of resultant forces (2N to 9N) when the forces are combined.
  • C. Option C is incorrect. 4.5N is also within the range of possible resultant forces (2N to 9N), thus it can be a resultant.
  • D. Option D is incorrect. 6.5N falls within the range of 2N to 9N, making it a feasible resultant force.

Q162. A battery is marked 9.0V. What does this mean?

  • A. Each coulomb of charge from the battery supplies 9.0J of electrical energy to the whole circuit
  • B. The battery supplies 9.0J to an external circuit for each coulomb of charge
  • C. The potential difference across any component connected to the battery will be 9.0V
  • D. There will always be 9.0V across the battery terminals

Explanation: The correct answer is Option A. A battery marked as 9.0V means it provides 9.0 joules of energy per coulomb of charge. This is the definition of voltage: the amount of energy per unit charge. Option B is misleading since the voltage applies to the entire circuit, not just the external parts. Option C is incorrect because the potential difference across components depends on circuit configuration. Option D is incorrect since the voltage across the terminals can vary due to factors like internal resistance and the load connected to the battery.

Why the other options are wrong
  • B. This statement is misleading. While it's true that the battery supplies 9.0J per coulomb, it applies to the entire circuit, not just the external part. The battery's voltage applies to the total energy per charge in the entire circuit.
  • C. This statement is incorrect. While the total potential difference provided by the battery is 9.0V, the potential difference across individual components depends on how they are connected in the circuit (e.g., series or parallel).
  • D. This is not always true. The voltage across the battery terminals can vary under different conditions, such as when a load is connected, due to internal resistance. The nominal voltage is 9.0V under ideal conditions.

Q163. Using monochromatic light, interference fringes are produced on a screen placed a distance D from a pair of slits of separation a. The separation of the fringes is x. Both a and D are now doubled. What is the new fringe separation?

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

Explanation: For double slits: Wavelength λ = xa / Dwhere x: separation of fringes,a: slit separation / distance between slits,D = distance from slits to screen.So, separation of fringes, x = λD / aWhen both a and D are doubled, the fringe separation x = λD / aThe separation between the fringes denoted by x is directly proportional to distance between the slits and screen and inversely proportional to separation between the two slits. Thus doubling the two quantities would ultimately result in cancellation of each other.

Why the other options are wrong
  • A. As per the explanation, this option is incorrect.For double slits: Wavelength λ = xa / Dwhere x: separation of fringes,a: slit separation / distance between slits,D = distance from slits to screen.So, separation of fringes, x = λD / aWhen both a and D are doubled, the fringe separation x = λD / aThe separation between the fringes denoted by x is directly proportional to distance between the slits and screen and inversely proportional to separation between the two slits. Thus doubling the two quantities would ultimately result in cancellation of each other
  • C. As per the explanation, this option is incorrect.For double slits: Wavelength λ = xa / Dwhere x: separation of fringes,a: slit separation / distance between slits,D = distance from slits to screen.So, separation of fringes, x = λD / aWhen both a and D are doubled, the fringe separation x = λD / aThe separation between the fringes denoted by x is directly proportional to distance between the slits and screen and inversely proportional to separation between the two slits. Thus doubling the two quantities would ultimately result in cancellation of each other
  • D. As per the explanation, this option is incorrect.For double slits: Wavelength λ = xa / Dwhere x: separation of fringes,a: slit separation / distance between slits,D = distance from slits to screen.So, separation of fringes, x = λD / aWhen both a and D are doubled, the fringe separation x = λD / aThe separation between the fringes denoted by x is directly proportional to distance between the slits and screen and inversely proportional to separation between the two slits. Thus doubling the two quantities would ultimately result in cancellation of each other

Q164. The internal energy of a fixed case of an ideal gas depends on:

  • A. Pressure, but not volume or temperature
  • B. Temperature, but not pressure or volume
  • C. Volume, but not pressure or temperature
  • D. Pressure and temperature, but not volume

Explanation: In an ideal gas the inter-molecular collisions are assumed to be absent and the collisions are perfectly elastic, thus, the gas only possesses kinetic energy and hence the internal energy of the ideal gas only depends on temperature,hence the answer will be B.

Why the other options are wrong
  • A. The internal energy of a fixed case of an ideal gas does not depend on Pressure, but not volume or temperature.
  • C. The internal energy of a fixed case of an ideal gas does not depend on Volume, but not pressure or temperature.
  • D. The internal energy of a fixed case of an ideal gas does not depend on Pressure and temperature, but not volume.

Q165. A spring obeying Hook‘s law has an unstretched length of 50mm and a spring constant of 400 Nm –1. What is the tension in the spring when its overall length is 70mm?

  • A. 8.0N
  • B. 28N
  • C. 160N
  • D. 400N

Explanation: In order to find the displacement x we subtract the untstrected length from the overall length. The stretched length is equal to displacement x.70-50=20F = kxF = 20*10-3*400F = 8 N

Why the other options are wrong
  • B. This option is incorrect because it likely results from a miscalculation of the displacement or incorrect application of Hooke's Law.
  • C. This option is incorrect and significantly overestimates the force, possibly due to multiplying the wrong values or misunderstanding the units involved.
  • D. This option incorrectly assumes that the force equals the spring constant, disregarding the displacement factor in Hooke's Law.

Q166. Which thermodynamic temperature is equivalent to 501.85 oC?

  • A. 775.00 K
  • B. 774.85 K
  • C. 228.85 K
  • D. 228.70 K

Explanation: Thermodynamic temperature, by contrast, is an absolute measure of the average total internal energy of an object or objects—namely its kinetic energy (energy of motion) plus contributions from other factors.From the following formula C=K-273.15 or K=C+273.15 we know that Celsius can be converted to kelvin scale to indicate thermodynamic temperature. 501.85 + 273.15 = 775 K

Why the other options are wrong
  • B. While close, this is not the correct conversion. Adding 273.15 to 501.85 oC results in 775.00 K, not 774.85 K.
  • C. This option is incorrect because it represents a significant underestimation of the temperature conversion from Celsius to Kelvin.
  • D. This is not the correct conversion. It results from an incorrect application of the conversion formula, leading to a value far from the correct one.

Q167. If a hole is bored through the center of the earth and a pebble is dropped in it, then it will:

  • A. Stop at the center of the earth
  • B. Drop to the other side
  • C. Execute SHM
  • D. None of the above.

Explanation: The pebble would fall down to the other side and in a ideal situation would oscillate between the two ends in simple harmonic motion. Therefore the answer would be C.

Why the other options are wrong
  • A. The pebble would not stop at the center of the earth because it will experience gravitational attraction from the mass on all sides of it, which will cause it to oscillate back and forth.
  • B. The pebble will oscillate back and forth through the center due to gravitational attraction until it comes to rest at the center.
  • D. this option is incorrect.

Q168. In a vibrating cord the point where the particles are stationary is called:

  • A. Crest
  • B. Anti-node
  • C. Node
  • D. Trough

Explanation: A node is a point along a standing wave where the wave has minimum amplitude. All the particles of the string execute SHM except nodes.

Why the other options are wrong
  • A. A crest is the highest point of a wave above the mean position. It is characterized by maximum displacement, not a stationary point.
  • B. An antinode is a point in a standing wave where the wave has maximum amplitude and maximum displacement, opposite of a stationary point.
  • D. A trough is the lowest point of a wave below the mean position. Similar to a crest, it is characterized by maximum displacement, not a stationary point.

Q169. The minimum frequency of incident light required to emit photoelectrons from the metal surface is called:

  • A. Critical frequency
  • B. Threshold frequency
  • C. Work function
  • D. None of the above

Explanation: This minimum frequency is also called the threshold frequency, and the value of ν0​\nu, start subscript, 0, end subscript depends on the metal. For frequencies greater than ν0​\nu, start subscript, 0, end subscript, electrons would be ejected from the metal.

Why the other options are wrong
  • A. This option is incorrect. The critical frequency is the highest frequency that can be reflected back to earth from the ionosphere.
  • C. Work function is a property of a material, which is defined as the minimum quantity of energy which is required to remove an electron to infinity from the surface of a given solid.
  • D. this option is incorrect.

Q170. A racing car accelerates uniformly through three gear changes with the following average speeds:20ms–1 for 2.0s, 40ms –1 for 2.0s, and 60ms –1 for 6.0s.What is the overall average speed of the car?

  • A. 12 ms–1
  • B. 13.3 ms–1
  • C. 48 ms–1
  • D. 40 ms–1

Explanation: V - overall average speedS - a total distancet - a total timeV = S/tS = V1*t1 + V2*t2 + V3*t3V1, V2, V3 - average speeds for each gear changest = t1 + t2 + t3t1, t2, t3 - times for each gear changesFinally:V = (V1*t1 + V2*t2 + V3*t3)/( t1 + t2 + t3) = (20*2+40*2+60*6)/(2+2+6)=48 m/sAnswer: the overall average speed equals 48 m/s.

Why the other options are wrong
  • A. This option is incorrect. It underestimates the average speed by using incorrect calculations.
  • B. This option is incorrect. It may result from summing the speeds directly without considering the time intervals.
  • D. This option is incorrect. It results from an incorrect application of the average speed formula.

Q171. Vapour pressure of a liquid can be measured by the Barometric method and Manometric:

  • A. Barometric method is more accurate than Manometric method.
  • B. Manometric method is more accurate than Barometric method.
  • C. Both are equally accurate and applicable.
  • D. Both methods are in use but are not reliable.

Explanation: Barometers are more limited in design and function than manometers, hence, manometers can calculate other pressures along with atmospheric pressure. On the other hand, barometers can calculate only atmospheric pressure. Manometric method are more accurate than barometric method because manometers are more accurate and therefore do not require definite level. The U-shaped manometers are more accurate because the level of high pressure gas on both sides helps in measuring the pressure of the liquid.

Why the other options are wrong
  • A. The Barometric method is generally less accurate than the Manometric method. Barometers are specifically designed to measure atmospheric pressure and have limitations due to their design and the potential health hazards of mercury.
  • C. While both methods can be used to measure pressure, they are not equally accurate. Manometers are generally more precise than barometers due to their design, which allows them to measure various pressures more effectively.
  • D. Both methods are indeed used, but the reliability varies. Manometers are typically more reliable for precise measurements compared to barometers, which are more limited in scope.

Q172. Several resistors are connected in parallel the resistance of their equivalent resistor will:

  • A. Increase
  • B. Decrease
  • C. Not change
  • D. None of these

Explanation: In a parallel circuit, the net resistance decreases as more components are added, because there are more paths for the current to pass through.

Why the other options are wrong
  • A. When the several resistors are connected in parallel, the equivalent resistance will not increase but will decrease because there are more paths for the current to pass through. As current passes through different paths, the internal resistance experienced by the current will also be less. In other words cross-section area A increases thus Net Resistance decreases.
  • C. In a parallel circuit, the net resistance decreases as more components are added, because there are more paths for the current to pass through.
  • D. Option B is correct, so this option is incorrect.

Q173. Which of the following series lie in the visible region?

  • A. Lyman
  • B. Paschen
  • C. Balmer
  • D. Pfund

Explanation: Four of the Balmer lines are in the technically visible part of the spectrum, with wavelengths between 400nm−700nm.The Lyman, Balmer, Paschen, and Pfund series are terms used to describe different series of spectral lines in the emission spectrum of hydrogen and other elements. These series correspond to transitions of electrons between different energy levels within the atom.1. **Lyman Series:** The Lyman series is a series of spectral lines in the ultraviolet region of the electromagnetic spectrum. It corresponds to transitions of electrons from higher energy levels to the n = 1 energy level (ground state) of the hydrogen atom. The lines in this series are named after the scientist Theodore Lyman who studied them.2. **Balmer Series:** The Balmer series is a series of spectral lines in the visible region of the electromagnetic spectrum. It corresponds to transitions of electrons from higher energy levels to the n = 2 energy level of the hydrogen atom. The lines in this series were discovered by Johann Balmer.3. **Paschen Series:** The Paschen series is a series of spectral lines in the infrared region of the electromagnetic spectrum. It corresponds to transitions of electrons from higher energy levels to the n = 3 energy level of the hydrogen atom. The lines in this series were studied by Friedrich Paschen.4. **Pfund Series:** The Pfund series is a series of spectral lines in the infrared region of the electromagnetic spectrum. It corresponds to transitions of electrons from higher energy levels to the n = 4 energy level of the hydrogen atom. The lines in this series were observed by August Herman Pfund.These series of spectral lines occur because of the quantized nature of energy levels in atoms. When electrons transition from higher energy levels to lower energy levels, they emit photons of specific energies, which correspond to specific wavelengths or frequencies of light. Each series corresponds to transitions ending at a specific lower energy level, and the lines within each series represent different possible paths for electrons to take while transitioning to that level.These spectral series provided crucial insights into the quantization of energy in atoms and played a significant role in the development of quantum mechanics.

Why the other options are wrong
  • A. The Lyman series is found in the ultraviolet region, formed when electrons transition from higher energy levels to the n = 1 level.
  • B. The Paschen series is located in the infrared region, resulting from electron transitions to the n = 3 level.
  • D. The Pfund series appears in the infrared region, occurring when electrons move to the n = 5 level.

Q174. Kirchoff‘s fist law (KCL) is based upon the law of conservation of:

  • A. Charge
  • B. Energy
  • C. Mass
  • D. Momentum

Explanation: Kirchhoff’s first law is a manifestation of law of conservation of charge, if there is no sink or source of charge at a point, the total total charge flowing towards the point must be equal to the total charge flowing away from it.

Why the other options are wrong
  • B. This is related to the first law of thermodynamics, which involves the conservation of energy, not charge. It states that energy can neither be created nor destroyed.
  • C. The conservation of mass states that mass is neither created nor destroyed in a closed system. This principle is more relevant to chemical reactions and does not pertain to electrical currents.
  • D. Momentum conservation is applicable in physics to describe objects in motion, stating that the total momentum remains constant in an isolated system. It is not related to the flow of electric charge.

Q175. Select the correct relation between wave and particle nature of radiation?

  • A. Wave-particle duality
  • B. Only wave nature
  • C. Only particle nature
  • D. Neither wave nor particle nature

Explanation: According to debroglie , all mater particles in motion have dual nature and thus he derived an equation which is E=hc/λ

Why the other options are wrong
  • B. This option is incorrect. While light exhibits wave-like properties such as interference and diffraction, it also displays particle-like properties, as demonstrated by the photoelectric effect.
  • C. This option is incorrect. Although light can behave like particles, such as photons in the photoelectric effect, it also exhibits wave properties, like interference patterns.
  • D. This option is incorrect. Extensive experimental evidence supports that light and matter can behave as both waves and particles under different conditions.

Q176. Change in concentration of a reactant is plotted against time and the slope dx/dt determined. The values of dx/dt are plotted against (a-x)2 and a straight line is obtained. It may be concluded that the reaction is:

  • A. First order
  • B. Second order
  • C. Third order
  • D. Zero order

Explanation: For a second-order reaction, dx/dt=k(a−x)2Plotting dx/dt vs (a−x)2 gives a straight line, exactly as described.

Why the other options are wrong
  • A. For a first-order reaction, dx/dt=k(a−x)1If we plot dx/dt​ vs (a−x), we get a straight line.In this case, the plot is vs (a−x)2, not (a−x), so first order is incorrect.
  • C. This option is incorrect because it suggests different order of reaction, which is not consistent with the observed behavior in this scenario.
  • D. For a zero-order reaction, dx/dt=k(a−x)0=kThe slope is constant, independent of (a−x)Plotting dx/dt​ vs any power of (a−x) would give a horizontal line, not necessarily vs (a−x)2

Q177. An object travels at constant speed arround a circle of radius 1.0m in 1.0s. What is the magnitude of its acceleration?

  • A. Zero
  • B. 1.0 ms–2
  • C. 2π2 ms–2
  • D. 4π2 ms–2

Explanation: In this problem, the object is moving in a circular path with a constant speed. While the speed remains constant, the direction of the object's velocity is continuously changing, which results in centripetal acceleration. The formula for centripetal acceleration, a = v2/r, is essential here. The speed of the object can be calculated as the distance traveled in one revolution (which is 2π meters) divided by the time taken (1 second), giving a speed of 2π m/s. Plugging this value into the formula gives:a = (2π)2/1 = 4π2 ms–2. Thus, Option D is the correct answer. Options A and B are incorrect as they overlook the acceleration due to the change in direction in circular motion, while Option C miscalculates the centripetal acceleration based on the given parameters.

Why the other options are wrong
  • A. This option suggests that there is no acceleration. However, since the object is moving in a circle, its direction is changing, which means there is acceleration present. Therefore, this option is incorrect.
  • B. This value does not account for the centripetal acceleration necessary for an object moving in a circular path. The object maintains a constant speed; however, it is still accelerating due to the change in direction. Thus, this option is incorrect.
  • C. This option does not accurately represent the centripetal acceleration for the given radius and time. The calculation for centripetal acceleration requires considering the speed and radius, leading to this incorrect answer.

Q178. An alternating current '1/A‘ varies with time 't/s‘ according to the equation I = 5sin(100πt). What is the mean power developed by the current in a resistive load of resistance 10?

  • A. 125W
  • B. 160W
  • C. 250W
  • D. 500W

Explanation: To find the mean power developed by the current in the resistive load, we first calculate the peak value of the current, which is 3.53. With a resistance of 10Ω, the power is determined using P = I²R = (3.53)²(10) = 125 W. The correct answer is 125W. The other options are incorrect because they do not accurately reflect the power calculated based on the values provided in the question.

Why the other options are wrong
  • B. This option is incorrect because the power calculated is not 160W based on the given current and resistance values.
  • C. This option is incorrect as the power calculated using the provided current and resistance values is not 250W.
  • D. This option is incorrect as the power calculated with the given values of current and resistance does not result in 500W.

Q179. The potential difference between a pair of similar and parallel conducting plates is known. What additional information is needed in order to find the electric field strength between the plates?

  • A. Separation of the plates
  • B. Separation and area of the plates
  • C. Permittivity of the medium; separation of the plates
  • D. Permittivity of the medium; separation and area of the plates

Explanation: The correct answer is Option A: Separation of the plates. The electric field strength between parallel conducting plates can be calculated using the formula E = V/d, where V is the potential difference and d is the distance between the plates. Therefore, knowing the separation of the plates is the additional information needed to determine the electric field strength in this scenario.Options B, C, and D include unnecessary information such as the area of the plates and permittivity of the medium, which are not directly required to find the electric field strength between the plates.

Why the other options are wrong
  • B. Although the area of the plates can affect the capacitance, it is not necessary to find the electric field strength between the plates. Only the separation distance is required for this calculation.
  • C. While the permittivity of the medium can impact the electric field strength, it is not essential to calculate it in this scenario. The separation of the plates alone is sufficient to determine the electric field strength between them.
  • D. Although the permittivity of the medium and the area of the plates are important factors in determining the overall electric field, they are not directly needed to find the electric field strength between the plates. Only the separation distance is required for this specific calculation.

Q180. In an AC capacitive circuit current and voltage phase relation is:

  • A. In-phase
  • B. Current leads voltage by 90o
  • C. Voltage leads current by 90o
  • D. Current leads voltage by 180o

Explanation: It can be seen that the phase at O is zero and the phase at the upper maximum is π/2. thus the current is leading the applied voltage by 90° or π/2.

Why the other options are wrong
  • A. In an in-phase relationship, current and voltage reach their maximum and minimum points simultaneously. This is not true for AC capacitive circuits.
  • C. This is true for an AC-Inductive circuit, not a capacitive one. In inductive circuits, the voltage leads the current by 90 degrees.
  • D. A phase difference of 180 degrees implies that the waveform is inverted, which is not the case in a capacitive circuit where the current leads by only 90 degrees.

Q181. A capacitor which has a capacitance of 1 farad (F) will:

  • A. Be fully charged in 1 second by a current of 1 Ampere
  • B. Store 1 coulomb of charge at potential difference of 1 volt
  • C. Gain 1 joule of energy when 1 coulomb of charge is stored on it
  • D. Discharge in 1 second when connected across a resistor of resistance 3 ohms

Explanation: A capacitance of 1F produces 1V of potential difference for an electric charge of one coulomb (1C). This statement also fully agrees with the formula C=Q/V.

Why the other options are wrong
  • A. This statement is incorrect because the time to charge a capacitor depends on the resistance and capacitance (RC time constant), not just the current. The capacitance of 1 farad relates to charge storage, not the rate of charging.
  • C. This statement is incorrect. The energy stored in a capacitor is given by the formula E = 1/2 QV. The energy is not directly related to the capacitance value in farads but depends on both the charge and the voltage.
  • D. This is incorrect. The discharge time of a capacitor through a resistor is determined by the RC time constant (τ = RC), not just by the capacitance value. It does not discharge in exactly 1 second unless specifically calculated with the resistance value.

Q182. What is the relationship between the intensity 'I‘ and the amplitude 'a‘ of a wave?

  • A. I a = constant
  • B. I/a2 = constant
  • C. I a2 = constant
  • D. I/a = constant

Explanation: The correct relationship between the intensity 'I' and the amplitude 'a' of a wave is option D: l/a2 = constant.

Why the other options are wrong
  • A. This option is incorrect because the intensity is proportional to the square of the amplitude, not the amplitude itself. Therefore, the product of intensity and amplitude is not constant.
  • C. This option is incorrect because it implies that intensity is inversely proportional to the square of the amplitude, which is not true. Intensity increases with the square of the amplitude.
  • D. This option is incorrect because it suggests a linear inverse relationship between intensity and amplitude, which does not match the actual physics where intensity is proportional to the square of the amplitude.

Q183. Which is a statement of the principle of conservation of momentum?

  • A. A force is equal to the rate of change of momentum of the body upon which it acts.
  • B. In a perfectly elastic collision, the total momentum and kinetic energy are conserved before and after the collision.
  • C. The momentum of a body is the product of its mass and velocity.
  • D. The total momentum of a system of interacting bodies remains constant, provided no external forces act on the system.

Explanation: The correct answer is D: The total momentum of a system of interacting bodies remains constant, provided no external forces act on the system. This statement accurately captures the principle of conservation of momentum, which asserts that in the absence of external forces, the total momentum of a closed system does not change.Option A describes Newton's second law, linking force and momentum change, but not conservation. Option B deals with elastic collisions specifically, where both momentum and kinetic energy are conserved, yet it doesn't express the general principle. Option C provides the formula for momentum but does not discuss conservation in a system.

Why the other options are wrong
  • A. This describes Newton's second law of motion, which relates force to momentum change, not the principle of momentum conservation itself.
  • B. This statement is true for elastic collisions but does not generalize the principle of momentum conservation beyond this specific scenario.
  • C. This defines momentum mathematically, without addressing the conservation aspect concerning a system of interacting bodies.

Q184. A projectile is launched at 45° to the horizontal with a force of initial kinetic energy "E". Assuming air resistance to be negligible, what will be the kinetic energy of the project when it reaches its highest point?

  • A. 0.50 E
  • B. 0.71 E
  • C. 0.70 E
  • D. E

Explanation: The following is the solution: When a projectile is launched at an angle of 45 degrees to the horizontal, its horizontal and vertical components of velocity are equal. So, the horizontal velocity (Vx) of the projectile at the highest point is the same as the initial velocity (Vi) multiplied by the cosine of the launch angle: Vx = Vi cos(45 degrees) Since we are considering only the horizontal component of velocity at the highest point, the kinetic energy (K.E-highest) at the highest point can be calculated as follows: K.E-highest = (1/2) x m x Vx2 Substituting the expression for Vx: K.E-highest = (1/2) x m x (Vi cos(45degrees))2 Now, cos(45 degrees) is equal to √2/2: K.E-highest = (1/2) x m x (Vi √2 /2)2 = (1/2) x m x (Vi2 (2 /4)) = (1/2) x m x (Vi2 / 2) Finally, since the initial kinetic energy (Ki) is given as "i," we can write the equation as: K.E-highest = Ki / 2 Therefore, the kinetic energy of the projectile at its highest point will be half of its initial kinetic energy, i.e., K.E-highest = Ki / 2 which can also be written as 0.5 Ki or as the question asked in terms of E, it will become 0.5 E, hence option A is correct.

Why the other options are wrong
  • B. Incorrect as per the formula
  • C. Incorrect as per the formula
  • D. Incorrect as per the formula

Q185. A mass accelerates uniformily when the resultant force acting on it:

  • A. Is zero
  • B. Is constant but not zero
  • C. Increases uniformly with respect to time
  • D. Is proportional to the displacement of the mass from a fixed point

Explanation: A mass accelerates uniformly when the resultant force acting on it is constant but not zero.

Why the other options are wrong
  • A. If the resultant force is zero, the mass will either remain at rest or continue to move at a constant velocity, implying no acceleration. This condition does not describe uniform acceleration.
  • C. If the force increases uniformly over time, the acceleration would also change, leading to non-uniform acceleration rather than uniform acceleration.
  • D. If the force is proportional to the displacement, this describes a harmonic motion, not uniform acceleration. In uniform acceleration, force remains constant and independent of displacement.

Q186. The prefix 'pico‘ stands for:

  • A. 106
  • B. 10
  • C. 10–12
  • D. 1012

Explanation: Pico = 10-12.

Why the other options are wrong
  • A. 10^6 is referred to as Mega and is denoted by the symbol 'M'. It is a much larger scale than pico.
  • B. 10^1 is known as deca, represented by 'da'. It signifies a scale that is larger than the base unit.
  • D. 10^12 is known as tera, denoted by 'T'. This is a very large scale, opposite of pico.

Q187. A student connects a 6 volt battery and a 12 volt battery in series and then connects this combination across a 10 Ω resistor. What is the current is the resistor?

  • A. 0.8 A
  • B. 1.8 A
  • C. 0.9 A
  • D. 2.6 A

Explanation: I = V/RI = 18/10I = 1.8 A

Why the other options are wrong
  • A. The total voltage was incorrectly calculated, leading to an incorrect current value.
  • C. Using an incorrect voltage value led to this result. Recheck the total voltage in the series connection.
  • D. An incorrect application of Ohm's Law or incorrect voltage calculation resulted in this value.

Q188. A step-up transformer is one that:

  • A. Increase the power
  • B. Increase the voltage
  • C. Increase the energy

Explanation: A step-up transformer is a transformer that increases the voltage from the primary coil to the secondary coil.

Why the other options are wrong
  • A. A transformer does not increase its power output; it only transfers power from the primary to the secondary coil. The power is the product of voltage and current, and ideally remains constant (minus losses).
  • C. A transformer does not increase energy. Energy conservation laws dictate that the energy input equals the energy output, excluding any losses due to inefficiencies.

Q189. The waves which do not require any medium for their propagation are called:

  • A. Mechanical waves
  • B. Sound waves
  • C. Tidal waves
  • D. Electromagnetic waves

Explanation: Waves that do not require any medium for their propagation are called electromagnetic waves.

Why the other options are wrong
  • A. Mechanical waves require a medium to travel, such as air, water, or solids. These waves involve the oscillation of particles within the medium. Examples include sound waves and water waves.
  • B. Sound waves are a type of mechanical wave that require a medium, like air or water, for propagation. They cannot travel through a vacuum.
  • C. Tidal waves, also known as water waves, are mechanical waves that require a medium such as water to propagate. They are influenced by gravitational forces and cannot exist in a vacuum.

Q190. In vacuum all electromagnetic waves have the same:

  • A. Speed
  • B. Energy
  • C. Frequency
  • D. Wavelength

Explanation: All electromagnetic radiations such as microwave, gamma rays or radio waves travel with a speed of light in a vacuum which is equal to 3.0 x 108 meters per second. This is because all massless particles travel with the speed of light. Since light is massless, therefore all particles travel with speed of light. So, the correct answer is option A.

Why the other options are wrong
  • B. Electromagnetic waves do not have the same energy because their energy is dependent on their frequency and wavelength. Higher frequency waves like gamma rays have more energy than lower frequency waves like radio waves.
  • C. The frequency of electromagnetic waves varies widely across the spectrum. For instance, radio waves have much lower frequencies than visible light or X-rays.
  • D. Electromagnetic waves have different wavelengths, as each type of wave occupies a different position on the electromagnetic spectrum. For example, visible light has a shorter wavelength than microwaves.

Q191. A ball is dropped from the roof of a very tall building.What is its velocity after falling for 5.0s?

  • A. 1.96 m/s
  • B. 9.80 m/s
  • C. 49.0 m/s
  • D. 98.0 m/s

Explanation: List the known and unknown values.u = initial velocity = 0 m/sv = final velocity = ?m/sa = g = acceleration due to gravity = 9.8 m/s²t = time interval = 5 ss = displacement = ? mCalculate the displacement using the following kinematic equation.s = ut + ½at²Since u = 0, the equation can be rewritten as:s = ½at²s = 0.5 × 9.8 m/s² × (5 s)² = 122.5 mCalculate the final velocity using the following kinematic equation.v = u + atv = 0 + (9.8 m/s² × 5 s) =49 m /s

Why the other options are wrong
  • A. This option assumes an incorrect calculation for the velocity after 5 seconds of free fall.
  • B. This option reflects the velocity after 1 second of free fall, not 5 seconds.
  • D. This option assumes an incorrect calculation for the velocity, perhaps doubling the correct value.

Q192. In liquid metal fast breeder reactor the moderator used is:

  • A. Graphite
  • B. Heavy water
  • C. Boron rods
  • D. Not required

Explanation: No moderator is used in the breeder reactor since fast neutrons are more efficient in transmuting U-238 to Pu-239.

Why the other options are wrong
  • A. Graphite is a common moderator in thermal reactors, where slowing down neutrons is beneficial. However, in a fast breeder reactor, the goal is to maintain high-speed (fast) neutrons, so no moderator like graphite is used.
  • B. Heavy water is used as a moderator in some types of reactors, such as CANDU reactors, to slow down neutrons. Fast breeder reactors, however, aim to utilize fast neutrons, so heavy water is not used as a moderator in this context.
  • C. Boron rods are used as control rods to absorb excess neutrons and control the fission reaction in various types of reactors. They are not used as moderators.

Q193. The de-Broglie wavelength of a rifle bullet of mass 0.02kg which is moving at a speed of 300ms–1 is (where h = 6.63×10 –34 Js)

  • A. 7.3 × 10 –34 m
  • B. 1.1 × 10 –34 m
  • C. 1.8 × 10 –35 m
  • D. 9.9 × 10 –34 m

Explanation: λ= h/mv = 6.626 x 10-34 / 0.02 x 300 = 1.1 × 10 -34 m

Why the other options are wrong
  • A. This calculation does not match the de-Broglie wavelength formula for the given values.
  • C. This result is too small, indicating a miscalculation in the use of the formula.
  • D. This is incorrect as it does not satisfy the calculation for the de-Broglie wavelength with the given parameters.

Q194. A shot is fired at an angle of 60o to the horizontal with kinetic energy E. If air resistance is ignored, the kinetic energy at the top of the trajectory is:

  • A. Zero
  • B. E/8
  • C. E/4
  • D. E/2

Explanation: K.E=E=1/2mv2K.E=1/2mvx2 (horizontal velocity)K.E= 1/2m x (vcos 60)2K.E=1/2mv2 (0.5)2K.E=1/2mv2 (o.25)K.E=1/2mv2 (¼)K.E= ¼ ( ½ mv2)K.E = ¼ (E)K.E= E/4 ans

Why the other options are wrong
  • A. At the top of the trajectory, vertical velocity is zero, but horizontal velocity is not, so kinetic energy is not zero.
  • B. This option miscalculates the horizontal component of velocity. The kinetic energy at the top is not E/8.
  • D. This option overestimates the kinetic energy. It does not account for the correct reduction due to the angle of projection.

Q195. The displacement 'x‘ of a particle at time 't‘ is given by x = 10 sin 4t. the particle oscillates with period.

  • A. π/10s
  • B. π/5s
  • C. π/4s
  • D. π/2s

Explanation: x=10sin4t , period T=?We know that x=x°sinθ x= x°sin wtx=x° sin2πftComparing10sin4t= x° sin2πft4=2πf4=2π/TT=2π/4T=π/2 sec ans

Why the other options are wrong
  • A. This period is incorrect. The angular frequency must match the standard form to find the correct period.
  • B. This period is incorrect. The formula used to find the period is not applied correctly here.
  • C. This period is incorrect. The angular frequency extracted from the equation leads to a different result.

Q196. By how many times does doubling the diameter of a wire and making it 10 times longer increase its resistance?

  • A. 2.5 times
  • B. 5 times
  • C. 10 times
  • D. 30 times

Explanation: The Resistance of a wire is calculated asR = P L/Awhere R = resitance of the wireL = Length of the wireA is the area of the wire = (pi d2)/4P = resistivity of the materialR1 = 4 P L /(pi d2)R2 = 4 P 10L /(pi (2 d)2)R2/R1 = 10/4 = 2.5 ANS

Why the other options are wrong
  • B. This option is incorrect. The resistance does not increase by five times. Consider the effects of changing both the diameter and the length on resistance.
  • C. This option is incorrect. Only the increase in length leads to a tenfold increase, but the change in diameter also affects the resistance.
  • D. This option is incorrect. The resistance does not increase by thirty times. The changes in diameter and length must be considered together.

Q197. A complex form of learning that requires the manipulation of mental concepts to arrive at adaptive behavior is:

  • A. Imprinting
  • B. Insight learning
  • C. Latent learning
  • D. Trial & error learning

Explanation: The complex form of learning that requires the manipulation of mental concepts for developing an adaptive behaviour is called insight learning.

Why the other options are wrong
  • A. Imprinting is a rapid form of learning that occurs during a critical period in early development, forming strong, irreversible bonds, especially between offspring and caregivers. It does not involve the manipulation of mental concepts, making it unsuitable for this context.
  • C. Latent learning occurs without immediate reinforcement and is not expressed until motivation is provided. It does not involve direct manipulation of mental concepts, so it is not correct in this context.
  • D. Trial and error learning is about trying different behaviors until finding the correct one. It does not involve deep mental manipulation or immediate insight, thus not fitting the description of complex learning requiring insight.

Q198. Choose the correct option. I always liked to lean _ the side of mercy

  • A. Over
  • B. On
  • C. Towards
  • D. About

Explanation: "Lean on" implies relying or depending on something, which fits the context of favoring or supporting the side of mercy.

Why the other options are wrong
  • A. "Lean over" suggests a physical action of bending or tilting, which doesn't align with the context of choosing or being inclined towards mercy.
  • C. "Lean towards" can suggest an inclination or preference, but it lacks the connotation of reliance or support inherent in "lean on."
  • D. "Lean about" is not a standard English expression and does not convey any meaningful relationship with the side of mercy.

Q199. I was born in Peshawar but I _ most of my childhood in the Mardan

  • A. Spends
  • B. Spent
  • C. Was spending
  • D. Is spending

Explanation: The sentence talks about a completed period in the past (childhood) with relevance to the present, which is best expressed using the present perfect tense "have spent."The present perfect is often used for an action that started at some time in the past and is still continuing now. So the correct option will be B.

Why the other options are wrong
  • A. This is the present simple tense, which is incorrect because it suggests a regular or habitual action, not one that occurred in the past.
  • C. This is the past continuous tense, which implies an ongoing action in the past but does not fit well with the idea of summarizing an entire period like childhood.
  • D. This is the present continuous tense, which is incorrect as it indicates an action happening right now, not a completed action in the past.

Q200. Select the most suitable synonym for the given word:ALAS

  • A. Oh
  • B. Hi
  • C. Bravo
  • D. Regrettably

Explanation: Alas is a term used to express grief, pity or concern thus, regrettably.

Why the other options are wrong
  • A. An expression used to draw attention or express surprise, but it does not convey sadness or regret.
  • B. A common greeting or salutation, unrelated to expressing sadness or disappointment.
  • C. An expression of approval or admiration, typically used to commend someone, not to express regret or sadness.

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