Pk Mdcat Mock 2 — Solved Past Paper with Answers

Q1. Choose the correctly structured sentence:

• A. Had he lived in England he would miss his family.
• B. Had he lived in England he would have missed his family.✓
• C. Had he lived in England he had missed his family.
• D. Had he live in England he will missed his family.

Explanation: Option B is correct because it is the only sentence that adheres perfectly to grammar rules. The first part of the sentence is in the past perfect tense (indicated by the verb form "had he"), so the next part of the sentence should also conform to the same tense so the correct context should be “would have”.

Q2. Complete the sentences by choosing the most appropriate option, from the given lettered choices.Our football team has _ the remarkable feat of winning the championship for three years in succession.

• A. Brought in
• B. Brought off✓
• C. Had brought
• D. Have brought
• E. Brought to

Explanation: The correct sentence is: 'Our football team has brought off the remarkable feat of winning the championship for three years in succession.' The phrase 'brought off' means to successfully achieve something difficult, which aligns with the context of the football team winning the championship repeatedly. Other options such as 'brought in', 'had brought', and 'brought to' do not convey this meaning. 'Have brought' is incorrect due to subject-verb agreement issues.

Q3. The sentence which has one dependent and one independent clause is called a:

• A. Compound sentence
• B. Complex sentence✓
• C. Compound complex sentence
• D. Exclamatory sentence

Explanation: The correct answer is: complex sentence.A complex sentence is a sentence that contains one independent clause (main clause) and one or more dependent clauses (subordinate clauses). The independent clause can stand alone as a complete sentence, while the dependent clause cannot.Example: "I went to the store because I needed milk." (Independent clause: "I went to the store"; Dependent clause: "because I needed milk")

Q4. Identify the tense used in the given sentence:"You are always working on your laptop."

• A. Present indefinite tense
• B. Present perfect tense
• C. Present continuous tense✓
• D. Present perfect continuous tense

Explanation: Present continuous tense is formed through the subject + present form of the verb (‘working’) + present participle of the verb (‘are’).Here, the given sentence that is 'You are always working on your Laptop' is the present tense.As we know by the rule of grammar, the definition of the present tense is the activity that is done in the current state not in the past or the future.The person seems to be always working on his/her laptop. This is a declarative sentence.The verb 'are working' is in the present continuous tense.Hence, the correct answer is present continuous tense.

Q5. Read the Passage and Answer the Question: Poetry begins in trivial metaphors, petty metaphors, "grace" metaphors, and goes on to the profoundest thinking that we have. Poetry provides the one permissible way of saying one thing and meaning another. People say. "Why don't you say what you mean?" We never do that, do we? We like to talk in parables and in hints and in directions whether from diffidence or some other instinct. What selection best describes the word "diffidence" as used in the passage?

• A. Shyness✓
• B. Consternation
• C. Bewilderment
• D. Reservations
• E. Caution

Explanation: Diffidence over here means modesty or shyness resulting from a lack of self-confidence. Consternation is a feeling of anxiety or dismay, typically at something unexpected. Bewilderment means to be surprised. Reservations means to have some thoughts about something even before interacting with them. Caution means being careful.

Q6. A/An _ egg foetid the cake.

• A. Addled✓
• B. Fermented
• C. Rancid
• D. Acidulous

Explanation: “Addled egg” means a rotten or spoiled egg. The sentence is describing an egg that ruined (foetid) the cake, so “addled” fits perfectly.

Q7. Identify errors in sentences:

• A. Neither the men who are listed as administrators nor the woman who is also listed has been appointed to the board.✓
• B. Neither the men who are listed as administrators nor the woman who is also listed have been appointed to the board.
• C. Neither the men who are listed as administrators nor the women who are also listed has been appointed to the board.
• D. Neither the men who is listed as administrators nor has the woman who is also listed been appointed to the board.

Explanation: When the subjects joined by or, nor, either ........ or, neither .........nor are of different persons, the verb agrees with the nearer.

Q8. Choose the correct sentence from the following.

• A. The cheery trees stand over the woodland ride.
• B. The cheery trees stand about the woodland ride.✓
• C. The cheery trees beside about the woodland ride.
• D. The cheery trees stand on the woodland ride.

Explanation: The phrase “stand about” means the trees are positioned around or near the woodland ride, which correctly describes their placement along the path.

Q9. Identify the word or phrase that needs to be changed for the sentence to be correct:I go by the post office every morning on my way too work.

• A. I
• B. Post office
• C. On
• D. Too✓
• E. No error

Explanation: The verb “too” is wrongly used here.” Too” implies intensity or inclusiveness.The correct verb to use here will be “to”, which is a preposition.

Q10. Choose the lettered word or phrase that is most nearly opposite in meaning to the word in capital letters. GLOOMY:

• A. Dark
• B. Bright✓
• C. Unexciting
• D. Faint

Explanation: "Gloomy" refers to a state or atmosphere that isdim, dark, or lacking in light. It often implies a feeling of sadness,melancholy, or a general lack of hope or optimism. Bright means giving out or reflecting much light; shining, so the total opposite. So option B is the answer as bright has the opposite meaning of gloomy.

Q11. I love you. I can't _ the thought of ever losing you.

• A. Bear✓
• B. Bare
• C. Support
• D. Think of

Explanation: “Bear” is correct because it means to tolerate or endure; the sentence expresses inability to endure the thought of losing someone.

Q12. Identify the word or phrase that needs to be changed for the sentence to be correct:

• A. Option A
• B. Option B✓
• C. Option C
• D. Option D
• E. Option E

Explanation: The send version of the verb is only used in the present tense in request form e.g Send me the email, send that version of the letter please etc. In the sentence past is being used so ‘sent’ will be used instead, so option B is the answer.

Q13. Choose the correct sentence from the following:

• A. We should pay maximum accolade for our national heroes
• B. We should pay maximum accolade in our national heroes
• C. We should pay maximum accolade to our national heroes✓
• D. We should pay maximum accolade from our national heroes

Explanation: The sentence 'We should pay maximum accolade to our national heroes' is correct because the preposition 'to' is commonly used to indicate the direction of an action, in this case, directing the accolade towards the national heroes. The other options misuse prepositions, altering the intended direction or source of the accolade.

Q14. Which of the following is grammatically correct?

• A. In the end, they found there money over they're by the ATM.
• B. In the end, they found they're money over their by the ATM.
• C. In the end, they found their money over there by the ATM.✓
• D. In the end, they found there money over their by the ATM.

Explanation: In this sentence, we have two homophones—their and there. In this first instance, we need to show possession, so the correct form is their. In the second instance, we need an adverb representing a place, so the correct form is there.

Q15. Choose the CORRECT sentence from the following options:

• A. The best places to eat are casual, fun and you can get a meal for cheap.
• B. The best places to eat are casual, fun, can be termed with inexpensive.
• C. The best places to eat are casual, funny, and cheapest.
• D. The best places to eat are casual, fun, and inexpensive.✓

Explanation: When read aloud, A is correct, unlike B and C. Between A and D, D is correct because a comma appears before "and".

Q16. Identify the errors and choose the correct option: I hope this letters finds in the best of your spirits.

• A. I hope this letter will find you in good of high spirits.
• B. I hope this letter finds you in the best of your spirits.✓
• C. I hope letter finds you in the best of spirits.
• D. I hope the letter found in greatest of sprite.

Explanation: There are two grammatical errors in the sentence above. An object (pronoun/noun) should be used to correctly identify the entity to whom the letter is sent.Option A is incorrect since it makes use of the future tense – indicated by “will find” – while the person will be reading the letter in the present. Option C and Option D are incorrect since they lack the determiner “this” which is necessary to indicate that the letter being mentioned is specific in nature (i.e. the letter that is being read currently). By elimination, Option B is correct.

Q17. Complete the sentence by choosing the most appropriate option: Some people _ claim to be vegetarians actually allow themselves to eat fish and chicken.

• A. That
• B. Which
• C. Whom
• D. Who✓

Explanation: People are nouns referring to person, the best pronoun to use in this case thus will be to use “who”.

Q18. Enzymes which are involved in transfer of electrons are known as?

• A. Oxidases
• B. Dehydrogenases
• C. Hydrolyses
• D. Both a and b✓

Explanation: Oxidases are enzymes that catalyze the transfer of electrons from a substrate to oxygen, while dehydrogenases are enzymes that catalyze the transfer of electrons from a substrate to an electron acceptor (such as NAD+ or FAD). Both of these types of enzymes are involved in the transfer of electrons, which is a key aspect of many metabolic pathways.

Q19. Which organ(s) in the male reproductive system produce gametes?

• A. Vas deferens
• B. Malpighian tubule system
• C. Seminiferous tubules✓
• D. Ejaculatory duct
• E. Testicular Duct System

Explanation: Opion A: Vas deferens is a long, muscular tube that transports sperm cells from the testes to the ejaculatory duct. It is about 18 inches long and is located in the scrotum. Option B: Malpighian tubular system is a network of tubules that are found in the kidneys. They are responsible for filtering blood and removing waste products. They do not play a role in the production of gametes. Option C: Seminiferous tubule is a network of tiny tubes found within the testes. They are where sperm cells are produced through a process called spermatogenesis. The seminiferous tubules are lined with cells that divide and differentiate into sperm cells. Option D: Ejaculatory duct is a short, muscular tube that carries sperm cells from the vas deferens to the urethra. It is about 1.5 inches long and is located in the prostate gland. Option E: Testicular duct system is a network of tubules that transports sperm cells from the seminiferous tubules to the epididymis. It is also known as the rete testis.

Q20. Vocal cords, which help in voice production are two thin edged fibrous bands, present in:

• A. Glottis
• B. Bronchus
• C. Larynx✓
• D. Trachea
• E. Pleura

Explanation: The vocal cords are two thin, fibrous bands located in the larynx or voice box, which is a part of the respiratory system. The vocal cords vibrate when air passes through them, producing sound and allowing us to speak.

Q21. Three-word equations are shown:P. Carbon dioxide + water gives glucose + oxygen Q. Glucose + oxygen gives carbon dioxide + water R. Glucose gives alcohol + carbon dioxide What is/are the equations for anaerobic respiration in yeast?

• A. P only
• B. Q only
• C. R only✓
• D. All of the above

Explanation: Anaerobic respiration in yeast, also known as alcoholic fermentation, is correctly represented by equation R: 'Glucose gives alcohol + carbon dioxide.' In this process, yeast cells break down glucose in the absence of oxygen to produce ethanol and carbon dioxide. This is crucial in industries such as brewing and baking, where yeast ferments sugars to produce alcohol and gas.Equation P represents photosynthesis, which is unrelated to respiration, while equation Q represents aerobic respiration that requires oxygen, unlike the anaerobic process in yeast.

Q22. If we add more substrate to an already occurring enzymatic reaction and it has no affect on the rate of reaction, the process is called?

• A. Denaturation
• B. Saturation✓
• C. Composition
• D. Inhibition

Explanation: If adding more substrate to an already occurring enzymatic reaction has no effect on the rate of the reaction, the process is called "enzyme saturation" or reaching the "maximum velocity" of the reaction. At low substrate concentrations, the reaction rate increases with increasing substrate concentration. However, once the enzyme is saturated (i.e., all active sites are occupied), adding more substrate does not increase the rate of the reaction, and the reaction has reached its maximum velocity.

Q23. Pseudopodia are:

• A. False feet developed in some unicellular organisms✓
• B. Small hairlike structures present on the unicellular organisms
• C. Long, tube like structures coming out of the mouth
• D. Suckers which are attached to the walls of intestines

Explanation: A pseudopod or pseudopodia is a temporary arm-like projection of a eukaryotic cell membrane that emerges in the direction of movement. The hair-like projections on unicellular organisms are called Cilia. The long tube-like structure connecting the mouth and the stomach is called the oesophagus. The head of some parasites contains structures, suckers which enable the parasite to attach to the gut wall. So option A is correct

Q24. The smaller (40S) of ribosome combines with larger subunit (60S) in the presence of Mg2+ ion to form _ particle.

• A. 100 S
• B. 90 S
• C. 80 S✓
• D. 70 S

Explanation: The S in the ribosomal subunits stands for svedberg units. It represents the different sedimentation rates of the ribosomes during centrifugation. The 60s and 40s ribosomal subunits join to form an 80S ribosome found in eukaryotes.

Q25. The following statements are about enzymes: 1. They are globular proteins except ribo-enzyme.2. They can be inhibited3. They are formed in the smooth endoplasmic reticulum 4. There are only found attached to Plasma membranes in the cell Which statements are correct for all enzymes?

• A. 1 and 4
• B. 2 and 4
• C. 1 and 2✓
• D. 1,2,3 and 4

Explanation: Enzymes are a type of protein, and they have a three-dimensional, globular shape. This shape is crucial for their function, as it allows them to interact specifically with their substrates. Competitive inhibitors are molecules that closely resemble the substrate of an enzyme. They compete with the substrate for binding to the active site of the enzyme. When a competitive inhibitor binds to the active site, it prevents the substrate from binding and, as a result, inhibits the enzyme's normal catalytic activity.

Q26. The type of bronchitis that causes no permanent damage to the lungs and lasts for two weeks is known as:

• A. Acute bronchitis✓
• B. Chronic bronchitis
• C. Coastal bronchitis
• D. Intercostal bronchitis

Explanation: 'Chronic bronchitis' is long-term inflammation of the bronchi. It is common among smokers. People with chronic bronchitis tend to get lung infections more easily.'Acute bronchitis' is a contagious viral infection that causes inflammation of the bronchial tubes - these are the airways that carry air into your lungs. When these tubes get infected, they swell and Mucus (thick fluid) forms inside them. This narrows the airways, making it harder for you to breathe.

Q27. Enzymes that are involved in the control and regulation of biological processes are?

• A. Allosteric enzymes
• B. Inhibitors
• C. Regulators✓
• D. None of these

Explanation: Regulatory enzymes are specialized forms of enzymes that have specific roles in metabolism, and their activity can be modulated by factors such as noncovalently bound metabolites or covalent modifications, responding rapidly to changes in cellular conditions.

Q28. True breeding variety is produced by which of the following?

• A. Cross-fertilization
• B. Self-fertilization✓
• C. Both Options A and B are correct
• D. None of these options is correct

Explanation: Option A : Cross-fertilization involves the fertilization of one plant by the pollen from another plant. This can lead to the mixing of different alleles from the two parent plants, resulting in offspring that are genetically diverse and may not have the same traits as the parent plants. Therefore, cross-fertilization is not a reliable method for producing true breeding varieties. Option B: With plants, true-breeding occurs when plants produce only offspring of the same variety when they self-pollinate. For instance, a plant that has blue flowers will produce only seeds that will grow into plants that have blue flowers. With true breeding, the trait is passed on to all subsequent generations.

Q29. It uses the single strand RNA as a template for making double stranded DNA:

• A. DNA polymerase
• B. DNA ligase
• C. Reverse transcriptase✓
• D. All of these

Explanation: Reverse Transcriptase is an enzyme that uses single-stranded RNA as a template to synthesize complementary double-stranded DNA (cDNA).This process is known as reverse transcription, and it occurs in retroviruses like HIV.Reverse transcriptase allows these viruses to insert their genetic material into the host's DNA.

Q30. Inside ovary, primary oocyte divides through first meiotic division, forming two haploid cells, the secondary oocyte and:

• A. Ovum
• B. Oogonium
• C. Follicle cell
• D. Polar body✓

Explanation: Inside the ovary, during the process of oogenesis, the primary oocyte undergoes the first meiotic division, resulting in the formation of two haploid cells. These cells are the secondary oocyte and a smaller cell called the first polar body. The first polar body is a smaller cell that contains a portion of the genetic material but minimal cytoplasm. The polar bodies typically do not play a direct role in fertilization and are eventually broken down or reabsorbed.

Q31. The optimum pH for enzyme arginase is?

• A. 9
• B. 9.3
• C. 9.7✓
• D. 10

Explanation: The optimum pH of arginase is typically around 9.5-10.5. Arginase is an enzyme that catalyzes the hydrolysis of arginine to ornithine and urea. The optimum pH for arginase activity can vary depending on the specific type of arginase and the organism it comes from. Generally, arginase is active in a slightly alkaline pH range.In humans, for example, arginase I, which is primarily found in the liver, has an optimum pH around 9.5. On the other hand, arginase II, found in other tissues, may have a slightly different optimum pH.

Q32. Cooperation of the two photosystems of the chloroplast is required for_

• A. ATP synthesis
• B. Reduction of NADP✓
• C. Cyclic photophosphorylation
• D. Oxidation of the reaction center of photosystem I

Explanation: For reduction of NADP to take place, non-cyclic electron flow should occur. Electrons excited from PS-II travel to PS-I, while those excited from PS-I finally reach NADP and reduce it to NADPH.

Q33. The cell A, in the given figure is:

• A. Gametophyte
• B. Spermatogonium✓
• C. Sperm
• D. Spermatocyte
• E. Spermatid

Explanation: In the process of spermatogenesis, spermatogonium is the diploid cell that divides mitotically to produce two daughter cells - one remains as spermatogonium for further division, and the other differentiates into primary spermatocyte. In the given figure, A is marked as spermatogonium, indicating that it is a diploid cell that will divide mitotically to produce more spermatogonia. Therefore, option B is the correct answer.

Q34. Drosophila flies with XXY genotype are females, but human beings with such genotype are abnormal males. It shows that:

• A. The Y-chromosome is essential for the sex determination of Drosophila.
• B. Y-chromosome is female determining in Drosophila.
• C. Y-chromosome is male-determining in human beings.✓
• D. Y-chromosome has no role in sex determination either in Drosophila or human beings

Explanation: 'Genic Balance Theory' was proposed by C.B. Bridges in 1922 for sex determination in Drosophila. It states that the ratio of the number of X-chromosomes to that of a complete set of autosomes determines the sex of Drosophila. According to this theory of sex determination, if the ratio of the X chromosome to a total number of sets of autosomes (X/A) is > 1, the organism will be super female. If the ratio of the X chromosome to the total number of sets of autosomes (X/A) falls between 1 and 0.50, the genotype will show an intersex phenotype. The X/A value is 1.0 for normal females and 0.5 for normal males. It clearly shows that in Drosophila autosome bears genes that incline for maleness and X chromosome bears genes that incline for femaleness; the Y-chromosome does not play any role in sex determination in Drosophila. It makes options A and B wrong. The presence of Y-chromosome in humans determines the male sex and its absence results in the female sex. Human males carry XY and females carry XX sex chromosomes. Option D is wrong and C is correct. Thus, the correct answer is option C.

Q35. The mobility of integral proteins can be measured by physical state of which of the following?

• A. Amino acids
• B. External phospholipids
• C. Membrane phospholipids✓
• D. Membrane appendages

Explanation: Option C is correct since integral proteins are embedded in the 'phospholipid bilayer' of the membrane, the mobility of the integral proteins is determined largely by the physical state of membrane phospholipids.

Q36. Which of the following is NOT a difference that would allow one to distinguish between a prokaryotic and a eukaryotic cell? Presence or absence of the nucleus Presence or absence of the cell wall Membrane bound versus no membrane bound organelles

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

Explanation: Eukaryotic cells have nucleus and membrane-bound organelles, which is not the property of prokaryotes.The cell wall is not a distinguishing feature between prokaryotes or eukaryotes.

Q37. Human accumulated glycogen is an example of

• A. phospholipid
• B. polysaccharides
• C. carbohydrates
• D. both b and c✓

Explanation: Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. The polysaccharide structure represents the main storage form of glucose in the body. Polysachharide is a type of carbohydrates.

Q38. ATP is used when _

• A. To synthesize the macromolecules
• B. To transport molecules and ions
• C. To perform mechanical work
• D. All of the above✓

Explanation: ATP (Adenosine Triphosphate) is a molecule that serves as the primary energy currency of the cell. It is used in various cellular processes to provide energy, for synthesizing macromolecules, ATP provides the energy needed for biosynthetic reactions that build complex molecules such as proteins, nucleic acids, and lipids.

Q39. Which is the correct order of energy transfer from accessory pigments to main photo synthetic pigment?

• A. Carotenoids, Chlorophyll a, Chlorophyll b
• B. Chlorophyll b, Carotenoids, Chlorophyll a
• C. Carotenoids, chlorophyll b, Chlorophyll a✓
• D. Chlorophyll a, Chlorophyll b, Carotenoids

Explanation: In the process of photosynthesis, energy transfer occurs in a specific sequence: from accessory pigments to the main photosynthetic pigment. Carotenoids capture light energy and pass it to chlorophyll b. Chlorophyll b then transfers this energy to chlorophyll a, where it is used in the photosynthetic reactions. Options A, B, and D are incorrect because they do not follow this correct sequence.

Q40. What are the functions of the inter, motor and sensory neurons in a reflex response?

• A. Option A✓
• B. Option B
• C. Option C
• D. Option D

Explanation: To relay nerve impulses from within the CNS, interneurons are used. To conduct the nerve impulses from the CNS to the effector, motor neurons are used. To conduct the nerve impulses from the receptors to the CNS, sensory neurons are used.

Q41. Which of the following statements are true about the capsomeres?

• A. It is an individual unit of the capsid✓
• B. It is a viral protein for replication
• C. It is a unit of nucleic acid in viruses
• D. All of the above

Explanation: Capsomeres are tiny subunits that make up the protein coat, referred to as the capsid. Capsomeres are known as capsid subunits, which are the outer protective covering of proteins that protect the virus' genetic material. It plays no role in the replication of the virus. So, option A is the best option.

Q42. All of these are inhibitors of enzymes except

• A. Antibiotics
• B. Anti metabolites
• C. Cyanide
• D. Succinic acid✓

Explanation: An enzyme inhibitor is a molecule that binds to an enzyme and decreases its activity, while succinic acid is a substrate.

Q43. Cyanobacteria help in nitrogen fixation because they have:

• A. Sodium channels
• B. Heterocysts✓
• C. Hormogonia
• D. Nitrogenase

Explanation: Cyanobacteria have specialized nitrogen-fixing cells called heterocysts which play a vital role in nitrogen fixation.

Q44. Acetyl CoA completely oxidizes to Carbon dioxide and liberates _.

• A. NADH and FADH
• B. NADP and FADP
• C. ATP
• D. ATP, NADH and FADH2✓

Explanation: When acetyl CoA undergoes complete oxidation in the citric acid cycle (also known as the Krebs cycle or tricarboxylic acid cycle), it liberates carbon dioxide and transfers high-energy electrons to carrier molecules. The overall chemical reaction for the complete oxidation of one molecule of acetyl CoA in the citric acid cycle is:Acetyl CoA+3NAD++FAD+GDP+Pi+2H2​O→2CO2​+3NADH+3H++FADH2​+GTP+CoAThe NADH and FADH2 generated in this process carry high-energy electrons to the electron transport chain, where they contribute to the synthesis of ATP through oxidative phosphorylation. The carbon dioxide produced is a byproduct of the decarboxylation reactions that occur during the citric acid cycle.

Q45. The respiratory chain electron carrier that directly binds oxygen is:

• A. Cytochrome a
• B. Cytochrome a3✓
• C. Cytochrome c1
• D. Cytochrome b

Explanation: The respiratory chain electron carrier that directly binds oxygen is cytochrome a3. Cytochrome a3 is the final electron carrier in the electron transport chain, and it is located in complex IV. When electrons are transferred to cytochrome a3, they are oxidized and combine with oxygen to form water.

Q46. The division of cocci in three planes results in formation of a:

• A. Tetrad
• B. Sarcina✓
• C. Grape like clusters
• D. All of the above options are correct

Explanation: Option A: Cells in a square arrangement, tetrads.Option B: The cocci are arranged in a cuboidal manner, as the cells are formed by regular cell divisions in three planes. Cocci that divide in three planes and remain in groups cube like groups of eightOption C: Staphylococcus aureus, which usually forms grape-like clusters, has the ability to form regularly arranged cell packets.

Q47. Which of the following is a copper containing protein in electron transport chain?

• A. Plastoquinone
• B. Cytochrome - C
• C. Plastocyanin✓
• D. Ferredoxin

Explanation: It serves as an electron transfer agent between the cytochrome complex which follows Photosystem II and the entry point to Photosystem I of the non-cyclic electron transfer process. The electron transport chain is a series of electron transporters embedded in the inner mitochondrial membrane that shuttles electrons from NADH and FADH2 to molecular oxygen. In the process, protons are pumped from the mitochondrial matrix to the intermembrane space, and oxygen is reduced to form water.

Q48. Steroids consist of _ 6 membered carbon rings and one 5 membered carbon ring.

• A. Four
• B. Three✓
• C. Two
• D. Five
• E. Six

Explanation: The steroid core structure is typically composed of seventeen carbon atoms, bonded in four "fused" rings: three six-member cyclohexane rings and one five-member cyclopentane ring.

Q49. Where is the double-stranded DNA of the bacteriophage found?

• A. Tail fibers
• B. Bacterial cytoplasm
• C. Base plate
• D. Head✓

Explanation: The double-stranded DNA of the bacteriophage is found in the head (capsid). Tail fibers and the base plate are structural components for attachment, while the bacterial cytoplasm only receives the DNA after injection. Thus, the correct location before infection is the capsid.

Q50. During spermatogenesis, the _, which are haploid cells eventually mature into spermatozoa/mature sperms:

• A. Spermatogonia
• B. Primary spermatocytes
• C. Spermatids✓
• D. Secondary spermatocytes

Explanation: Option A, spermatogonia, are diploid cells and are the first stage in the process of spermatogenesis. They have not undergone meiotic division, and as such are diploid.Option B, primary spermatocytes, are also diploid cells, as they arise from mitotic divisions of the spermatogonia which themselves are diploid. They are not a product of meiosis.Option C, spermatids, is the correct answer. This is because they are the end product of Meiosis II and as such are haploid cells. Furthermore, they themselves are the direct precursors to mature spermatozoa as they further differentiate to form mature sperm cells.Option D, secondary spermatocytes, are also haploid cells and are the cells which give rise to spermatids. This is not the correct answer as the question is asking for a haploid cell that matures into spermatozoa/mature sperm cells. Secondary spermatocytes give rise to spermatids first which then go on to mature into spermatozoa so, spermatids fit the given scenario.

Q51. The genotype of blood group 'AB' in humans is _.

• A. IA IB✓
• B. IB Io
• C. IA IA
• D. IoIo

Explanation: ABO blood type in humans is determined by 3 alleles IA, IB (Dominant), and i (Recessive) Genotype IA shows blood group A. Genotype TB shows blood group B. Genotype Io shows blood group O. But, IA & IB are co-dominant alleles means neither of the dominant alleles can mask the expression of other dominant alleles. So, the genotype IA IB shows blood group AB.

Q52. Breaking of the terminal phosphate of ATP releases about _ kcal/mol of energy.

• A. 20 kcal/mol
• B. 12kcal/mol
• C. 3.5kcal/mol
• D. 7.3kcal/mol✓

Explanation: The release of terminal phosphate in a single ATP molecule occurs using water; the energy released is equivalent to 7.3 kcal/mol.

Q53. The number of functional parts in the forebrain are:

• A. 2
• B. 3✓
• C. 4
• D. 5

Explanation: The forebrain can be divided into three functional parts, namely the thalamus, the limbic system, and the cerebrum.1. Thalamus: It acts as the main relay station for your brain; all motor and sensory signals pass through this structure in the centre of the brain.2. Limbic system: This is the part of the brain involved in behavioural and emotional responses.3. Cerebrum: This is the largest part of the brain, and it is divided into two hemispheres, namely the cerebral hemispheres. Areas within the cerebrum control muscle function and speech, along with thoughts, emotions, reading, writing, and learning.

Q54. All of the following are examples of substances found in bacteria or archaea except :

• A. Peptidoglycans
• B. Flagellin
• C. Bacteriorhodopsin
• D. Chitin✓

Explanation: Chitin is found in fungal cell walls 1 arthropod exoskeletons, not in bacteria or archaea, whereas peptidoglycan, flagellin, and bacteriorhodopsin are found in bacteria/archaea.

Q55. Which of the following is a compensation point?

• A. Leaves respire utilizing O2 and releasing CO2
• B. Photosynthesis and respiration occur at the same rate, resulting in no net exchange of gases between the atmosphere and plants✓
• C. The rate of photosynthesis increases, resulting in a net release of oxygen and uptake of CO2
• D. The rate of respiration exceeds the rate of photosynthesis, resulting in a net release of carbon dioxide

Explanation: The compensation point is a specific condition in plant physiology where the rates of photosynthesis and respiration are equal. At this point, plants consume oxygen and carbon dioxide at the same rate they produce them, resulting in no net exchange of gases with the atmosphere. Option B correctly identifies this condition. Option A describes only respiration, Option C describes active photosynthesis with net oxygen release, and Option D describes a situation where respiration is dominant, all of which do not fit the definition of a compensation point.

Q56. If the non-protien part is loosely attached to the protein part in the enzyme, it is known as _.

• A. Coenzyme✓
• B. Prosthetic group
• C. Cofactor
• D. Apoenzyme

Explanation: Prosthetic groups are compounds bound to enzymes by a covalent bond and their change from one form to another and back takes place in a single catalytic cycle. Coenzymes are organic molecules and quite often bind loosely to the active site of an enzyme. The term cofactors unite coenzymes and prosthetic groups. The meaning of apoenzyme is a protein that forms an active enzyme system by combination with a coenzyme.

Q57. Long bones function in

• A. support
• B. support, erythrocyte and leucocyte synthesis✓
• C. support and erythrocyte synthesis
• D. erythrocyte formation

Explanation: Long bones strengthen the legs and arms, provide support and also synthesise erythrocytes and leucocytes due to presence of bone marrow in their cavities.

Q58. The enzymes required for the Krebs cycle are found in _.

• A. F1 particles
• B. Lysosomes
• C. Cytoplasm
• D. Matrix✓

Explanation: The Krebs cycle enzymes are membrane proteins found within the matrix of the mitochondria except for succinate dehydrogenase which is an integral membrane protein locked to the inner mitochondrial membrane.F1 particle is found in the matrix of mitochondria and is found attached to the cristae. It plays a very important role in the production of ATP molecules as it contains an enzyme called ATPaseA lysosome is a membrane-bound cell organelle that contains digestive enzymes.The cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane.

Q59. A bacteria without flagella is called:

• A. Amphitrichous
• B. Atrichous✓
• C. Lophotrichous
• D. Peritrichous

Explanation: Bacterial cells which do not contain any flagella are called atrichous.

Q60. If we cross round yellow seeded plant with green wrinkled seeded plants, what will be phenotypic ratio at F2 generation?

• A. 9:3:3:1✓
• B. 9:4:3:2
• C. 3:9:3:1
• D. 8:3:3:2
• E. 9:1:3:3

Explanation: The answer is A since the question asks us to find the ratio of the F2 generation so we can assume the given plants are homozygous with one being homozygous dominant for both characteristics and the other being homozygous recessive. We infer their homozygosity from the fact that they are from the parental generation and the F1 generation, consequently would be heterozygous for both properties as well. For F2 generation, we can draw a Punnett square to find the ratio when the heterozygous plant of the F1 generation self-pollinates.

Q61. Genes that influence height in humans are:

• A. Codominant
• B. Epistatic
• C. Polygenes✓
• D. Pleiotropic

Explanation: Option A: Both alleles of a gene are expressed equally and independently in the 'Heterozygous' condition. Offspring show the phenotype of both parents. Option B: One gene suppresses the expression of another gene that is located at a different locus. Option C: 'Polygenes' control continuously varying traits, which are controlled by alleles of two or more separate genes located at different loci. The genes are called polygenes. In humans, skin color, height, and intelligence are examples of polygenic traits. Option D: 'Pleiotropy' refers to multiple effects of a single gene.

Q62. The optimum pH of catalase is:

• A. Slightly alkaline✓
• B. Highly acidic
• C. Highly alkaline
• D. Slightly acidic

Explanation: The optimum pH of catalase is slightly alkaline, with a range of 6.8 to 7.2. This means that catalase works best at a pH that is slightly higher than neutral. Catalase is an enzyme that is found in most cells, and it is responsible for breaking down hydrogen peroxide. Hydrogen peroxide is a toxic substance, so catalase is important for preventing cell damage.

Q63. Which of the following is basic function of bacterial slime capsule?

• A. Protection from enviroment
• B. Protection from engulfment✓
• C. Protection from osmotic lysis
• D. All of the above

Explanation: Capsule is tightly bound to the bacterial cell. It is a part of the cell envelope. It protects cells from engulfment by Eukaryotic cells such as macrophages and it also protects the cells from pathogenicity. Hence option B is correct.Option A and C is incorrect because the cell wall of bacteria protects the cell against osmotic lysis and against environment.

Q64. Phosphofructokinases enzyme converts fructose-6-phosphate into:

• A. Fructose-1,4-phosphate
• B. Fructose-1,6-bisphosphate✓
• C. Bisphosphate
• D. Fructose

Explanation: Phosphofructokinase (PFK) plays a critical role in glycolysis by catalyzing the conversion of fructose-6-phosphate into fructose-1,6-bisphosphate. This reaction involves the transfer of a phosphate group from ATP to fructose-6-phosphate, forming fructose-1,6-bisphosphate and ADP. This step is key for regulating the glycolytic pathway. Option B is correct because it reflects the specific phosphorylated product of this reaction. Option A is incorrect because it specifies the wrong positions for phosphorylation. Option C is too vague, as it does not specify the positions of the phosphate groups. Option D is incorrect because it suggests a conversion that does not occur in this enzymatic reaction.

Q65. Chlorophyll b is found in which organisms?

• A. Green plants
• B. Green algae
• C. Animals
• D. Both Options A and B are correct✓

Explanation: There are four types of chlorophyll: chlorophyll a, found in all higher plants, algae, and cyanobacteria; chlorophyll b, found in higher plants and green algae; chlorophyll c, found in diatoms, dinoflagellates, and brown algae; and chlorophyll d, found only in red algae.

Q66. Which reaction is catalyzed by the enzyme RuBisCO?

• A. Carboxylation of ribulose bisphosphate (RuBP)✓
• B. Conversion of triose phosphate (TP) to ribulose phosphate (RuP)
• C. Oxidation of giycerate-3-phosphate (GP)
• D. Reduction of glycerate-3-phosphate (GP)

Explanation: RuBisCO catalyzes the carboxylation of ribulose-1,5-bisphosphate (RuBP) by incorporating carbon dioxide (CO2). This is the initial step in the Calvin Cycle, leading to the formation of two molecules of 3-phosphoglycerate (3-PGA).

Q67. Where does the Calvin Cycle occur?

• A. Stroma✓
• B. Cytosol
• C. Thylakoid Membrane
• D. No specific location

Explanation: The Calvin Cycle, also known as the dark reactions or light-independent reactions of photosynthesis, occurs in the stroma of the chloroplasts. The chloroplast is an organelle found in plant cells and some other eukaryotic cells, and it is the site of photosynthesis.

Q68. Syphilis is caused by:

• A. Coccus
• B. Bacillus
• C. Spirillum
• D. Spirochete✓

Explanation: Syphilis, systemic disease that is caused by the spirochete bacterium Treponema pallidum. Syphilis is usually a sexually transmitted disease, but it is occasionally acquired by direct nonsexual contact with an infected person, and it can also be acquired by an unborn fetus through infection in the mother.

Q69. Only one ovary is functional at a time in:

• A. Human
• B. Eagle
• C. Chicken✓
• D. Pigeon and human

Explanation: Unlike most female animals, which have two functioning ovaries, the chicken usually has only one. The right ovary stops developing when the female chick hatches, but the left one continues to mature.

Q70. Which of the following types and functions of the neuron is correct?

• A. Sensory neurons carry impulses from sensory receptors to the CNS; interneurons relay signals within the CNS; motor neurons transmit impulses from the CNS to muscles or glands✓
• B. Motor neurons carry sensory impulses to the CNS; interneurons transmit impulses to muscles; sensory neurons relay signals within the CNS
• C. Interneurons carry impulses from effectors to the CNS; sensory neurons transmit impulses from the CNS to interneurons; motor neurons pass signals within the CNS
• D. Sensory neurons transmit impulses from the CNS to effectors; motor neurons carry sensory information to the CNS; interneurons connect sensory to motor neurons outside the CNS

Explanation: Sensory neurons function to carry the sensory information to the CNS. Interneurons transfer impulses from sensory to motor neurons, remaining within the CNS. Motor neurons are neurons that transmit impulses fromthe CNS to the effectors.

Q71. During feedback inhibition, which of the following structural part of enzyme is involved?

• A. Active site
• B. Binding site
• C. Catalytic site
• D. Allosteric site✓

Explanation: Feedback inhibition is usually accomplished through something called an “allosteric site” – a site on an enzyme, that changes the shape of an enzyme, and subsequently, the behavior of the active site.

Q72. The function of calcium ions in muscle contraction is to:

• A. Polarize visible light
• B. Aid in the transmission of nerve impulse
• C. Bind to troponin molecule and cause them to move✓
• D. Bind to tropomyosin molecule and cause them to form cross bridges

Explanation: Calcium ions bind to troponin (specifically troponin C), initiating a shape change that moves tropomyosin away from actin binding sites, allowing myosin heads to form cross-bridges with actin filaments. This is the key step in muscle contraction. Therefore, option C is correct. Option A is irrelevant as it pertains to the light polarization properties of muscle fibers. Option B is incorrect because, although calcium ions are involved in nerve impulse transmission, this is not their primary role in muscle contraction. Option D is incorrect, as calcium ions do not directly bind to tropomyosin but influence its movement indirectly through troponin binding.

Q73. Human cells maintain concentration gradients across their plasma membranes, such that there is a high sodium concentration outside the cell and a high potassium concentration inside the cell. Suppose that within the cell membrane are sodium leak channels or carrier proteins. These channels would allow sodium to:

• A. Move out of the cell by simple diffusion
• B. Move into the cell by simple diffusion
• C. Move out of the cell by facilitated diffusion
• D. Move into the cell by facilitated diffusion✓

Explanation: As the question mentions, there is a high concentration of sodium ions outside the cell, which means that through sodium leaky channels, the sodium ions should move inside the cell, not outside. The type of movement that occurs through channels or carrier proteins down the concentration gradient is called facilitated diffusion. That is why the answer is D.

Q74. Which of the following statements is a correct distinction between autotrophs and heterotrophs?

• A. Only heterotrophs require chemical compounds from the environment
• B. Cellular respiration is unique to heterotrophs
• C. Only heterotrophs have mitochondria
• D. Autotrophs, but not heterotrophs, can nourish themselves beginning with entirely inorganic nutrients✓

Explanation: Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other inorganic nutrients. Heterotrophs depend on autotrophs either directly or indirectly. OPTION A: Autotroph needs chemical compounds from the environment. OPTION B: Cellular respiration is present in both heterotrophy and autotrophy, as both of them require energy in the form of ATP, which is formed by cellular respiration. OPTION C: Both have mitochondria in their cells, which generate energy for cells and work as the powerhouses of the cell. OPTION D: Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other inorganic nutrients.

Q75. Select the correct statement.

• A. The vertebral column has 10 thoracic vertebrae.
• B. The joint between adjacent vertebrae is a fibrous joint.
• C. A decreased level of progesterone causes osteoporosis in old people.
• D. Accumulation of uric acid crystals in joints causes their inflammation✓

Explanation: Thoracic vertebrae are 12 in numbers.Joints between adjacent vertebrae are cartilagenous joints and the opposing surfaces are connected by fibrocartilage which allows very little movement. Osteoporosis is a disease characterised by low bone mass and loss of bone tissue that may lead to weak and fragile bones. Osteoporosis occurs when there is an imbalance between new bone formation and old bone resorption. In osteoporosis, the osteoblastic (bone forming) activity in the bone usually is less than normal and consequently the rate of bone deposition is depressed. Estrogens inhibit osteoclastic (bone resorption) activity in the bones and therefore stimulate bone growth. Gout occurs when urate crystals accumulate in your joint, causing the inflammation and intense pain of a gout attack hence it is the correct option.

Q76. Which of these enzymes works best at a pH of 9.70?

• A. Arginase✓
• B. Pancreatic enzyme
• C. Catalase
• D. Chymotrypsin

Explanation: Arginase operates optimally at a pH of around 9.7. It is involved in the urea cycle, converting arginine into ornithine and urea.

Q77. In the male reproductive tract, sperm cells follow a specific path. Which of the following structures do sperm cells enter after traveling through the epididymis?

• A. Urethra
• B. Seminiferous tubules
• C. Ejaculatory duct
• D. Vas deferens✓

Explanation: After traveling through the epididymis, sperm cells enter the vas deferens. The vas deferens, also known as the ductus deferens, is a muscular tube that extends from the epididymis through the inguinal canal into the pelvic cavity. It serves as a conduit for the transport of sperm from the epididymis to the ejaculatory duct during ejaculation.

Q78. Which hormone causes the contraction walls of the uterus during the process of birth?

• A. FSH
• B. STH
• C. Oxytocin✓
• D. LTH

Explanation: During birth the oxytocin causes the smooth muscle in the uterine wall to contract.Growth hormone (GH) or somatotropin, also known as human growth hormones (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals.Follicle stimulating hormone is one of the hormones essential to pubertal development and the function of women's ovaries and men's testes. In women, this hormone stimulates the growth of ovarian follicles in the ovary before the release of an egg from one follicle at ovulation.Prolactin, also known as lactotropin (LTH), is a protein best known for its role in enabling mammals, usually females, to produce milk.

Q79. Deficient production of hormones by adrenal glands results in:

• A. Cushing's syndrome
• B. Addison's disease✓
• C. Diabetes Mellitus
• D. Goiter
• E. Epilepsy

Explanation: Deficient production of hormones by the adrenal glands leads to Addison's disease, a condition characterized by insufficient levels of cortisol and aldosterone. This can result in symptoms like fatigue, weight loss, and low blood pressure. The other options do not result from adrenal hormone deficiency: Cushing's syndrome is due to excessive cortisol; Diabetes Mellitus involves insulin, not adrenal hormones; Goiter is related to thyroid issues; and Epilepsy is a neurological condition, unrelated to the endocrine function of the adrenal glands.

Q80. Haemoglobin exhibits a:

• A. Secondary structure
• B. Primary structure
• C. Quaternary structure✓
• D. Tertiary structure

Explanation: Haemoglobin has a quaternary structure. It consists of two pairs of different proteins, designated the α and β chains. There are 141 and 146 amino acids in the α and β chains of haemoglobin, respectively. As in myoglobin, each subunit is linked covalently to a molecule of heme.

Q81. The photosynthetic pigments of plants are arranged as clusters in thylakoid membranes. The reaction centers of these clusters consist of _ molecules.

• A. Chlorophyll✓
• B. ATP
• C. Carotenoids
• D. Glucose

Explanation: Chlorophyll, is the correct answer because they are the photosynthetic pigment that comprises the reaction centers of these clusters, or photosystems 1 and 2. Light energy collected by the photosystem is transferred to the reaction center, which consists of chlorophyll molecules, after which an electron is excited and the subsequent steps of the light-dependent reaction of photosynthesis occur.

Q82. Glycolipids and glycoproteins have a structural role in which matrix structure of animal and bacterial cell?

• A. Extracellular✓
• B. Intracellular
• C. Both A and B
• D. Plasma membrane

Explanation: Glycolipids and glycoproteins are crucial components of the extracellular matrix (ECM) in animal cells and the bacterial cell wall. They help maintain cell structure and facilitate communication between cells and their environment. The ECM is a complex network composed of proteins, carbohydrates, and lipids, providing structural support to cells. Although glycolipids and glycoproteins are also present in plasma membranes, their primary structural function lies in the extracellular matrix, not within the intracellular space.

Q83. Non-toxic vitamins include which of the following?

• A. Vitamin C
• B. Vitamin B
• C. Both A and B✓
• D. None of the above

Explanation: Vitamin B is important for our body because it keeps our hair eyes and skin healthy while vitamin C boosts collagen synthesis and immune function, making both not toxic and therefore option C is correct.

Q84. Pathway of energy production from food used by muscles is:

• A. Food → ATP → creatine phosphate → protein
• B. Food → glycogen → ATP → creatine phosphate
• C. Food → glycogen → creatine phosphate → ATP✓
• D. Food → protein → creatine phosphate → ATP

Explanation: The correct pathway for energy conversion in muscles starts with food being broken down into glycogen. Glycogen is then converted to glucose, which is used to regenerate creatine phosphate. Creatine phosphate is a quick source of energy, which is then metabolized to form ATP, the main energy currency of the cell. Options A, B, and D are incorrect because they misrepresent the sequence of energy transformations or the role of the protein in this context.

Q85. Louis Pasteur discovered a vaccine against which disease first?

• A. Anthrax✓
• B. Smallpox
• C. Rabies
• D. HIV

Explanation: Pasteur discovered a vaccine against Anthrax first and then Rabies.The vaccine of smallpox was discovered by Edward Jenner.

Q86. Nitrogen dioxide decomposes on heating according to the following equation: 2NO2 (g) ⇌ 2NO (g)+ O2 (g) When 4 moles of nitrogen dioxide were put into a 1 dm3 container and heated to a constant temperature, the equilibrium mixture contained 0.8 moles of oxygen. What is the numerical value of the equilibrium constant, Kc, at the temperature of the experiment?

• A. Option A
• B. Option B
• C. Option C
• D. Option D✓

Explanation: To find the numerical value of the equilibrium constant, Kc, we need to use the equilibrium concentrations of the reactants and products.According to the given information, we start with 4 moles of nitrogen dioxide (NO2) in a 1 dm^3 container. This means the initial concentration of NO2 is 2.4 moles/1 dm^3 = 2.4 M.At equilibrium, we have 0.8 moles of oxygen (O2) in the 1 dm^3 container. The equilibrium concentration of O2 is therefore 0.8 M.Since the stoichiometry of the balanced equation is 2NO2 ⇌ 2NO + O2, the equilibrium concentration of nitrogen monoxide (NO) will also be 2 times the concentration of O2, which is 2 x 0.8 M = 1.6 M.Now we can write the expression for the equilibrium constant, Kc:Kc = [NO]2 [O2] / [NO2]2Kc = (1.6 M)2 * (0.8 M) / (2.4 M)2This is numerical so it can only have one correct option.

Q87. Bond energy:I. is the energy required to break a bond between two atoms in a diatomic molecule II. Is taken as the energy released in forming a bond form free atoms III. Is the measure of the strength of bond.

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

Explanation: Bond energy is a critical concept in understanding chemical bonding and is defined through multiple perspectives:Option I: It is indeed the energy required to break a bond between two atoms in a diatomic molecule, indicating how much energy is needed to overcome the bond's strength.Option II: The energy released when a bond is formed from free atoms is also a measure of bond energy, showing the stabilization energy provided during bond formation.Option III: Bond energy serves as an indicator of bond strength; stronger bonds require more energy to break, thus having higher bond energies.Therefore, all three options collectively provide a comprehensive understanding of bond energy, making Option E the correct choice. Each statement highlights a different but related aspect of bond energy, and understanding this concept requires integrating all perspectives.

Q88. From four substances described below, which is most likely to be an ionic compound?

• A. Melting point 1500°C, molten substance is a poor electrical conductor
• B. Melting point 20°C, molten substance does not conduct electricity
• C. Melting point 150°C, molten substance does not conduct electricity
• D. Melting point 800°C, molten substance readily conducts electricity✓

Explanation: Ionic compounds have high melting points. They are poor conductors in solid state but very good conductors of electricity in molten state.

Q89. Which factor does affect the equilibrium constant Kc for a reaction?

• A. Temperature✓
• B. Pressure
• C. Catalyst
• D. Initial concentrations

Explanation: Changing the temperature shifts the equilibrium position based on whether the reaction is endothermic (absorbs heat) or exothermic (releases heat), according to Le Chatelier's Principle.3 Since the ratio of products to reactants changes, the value of K must also change.

Q90. In the Lucas test, tertiary alcohols form an oily layer of alkyl halide _.

• A. On heating
• B. Immediately✓
• C. After 5-10 minutes
• D. After 20 minutes

Explanation: Option A: On heating is incorrect because heating is not required for the reaction to take place. The reaction occurs at room temperature. Option B: The Lucas test in alcohols is a test to differentiate between primary, secondary, and tertiary alcohols. Tertiary alcohols react immediately with the Lucas reagent as evidenced by turbidity owing to the low solubility of the organic chloride in the aqueous mixture. Option C: After 5-10 minutes is also incorrect because the reaction is very fast and occurs immediately. The turbidity or precipitation of the solution is typically observed within a few seconds to a minute after the addition of the Lucas reagent. Option D: After 20 minutes is also incorrect because the reaction is very fast and occurs immediately. The turbidity or precipitation of the solution is typically observed within a few seconds to a minute after the addition of the Lucas reagent.

Q91. The number of sigma and pi bonds in 1-butene-3-yne?

• A. 5 sigma and 5 pi
• B. 7 sigma and 3 pi✓
• C. 8 sigma and 2 pi
• D. 6 sigma and 4 pi

Explanation: The number of sigma and pi-bonds in 1-butene 3-yne are 7 sigma and 3 pi. It has one C=C double bond which contains one pi bond. It has one C≡C triple bond which contains two pi bonds. It has 3 carbon carbon sigma bonds and 4 C−H pi bonds.

Q92. The addition of HBr to an unsymmetrical alkenes follows?

• A. Direct addition
• B. Markovnikov's addition✓
• C. Anti Markovnikov's addition
• D. Dehydration

Explanation: Since the alkene and the reagent (HBr) are both unsymmetrical markovnikov’s rule will be followed. According to which the negative part of the reagent ( bromide ion) will attach to the carbon with fewer hydrogen atoms. Dehydration is when a water molecule is removed i.e., from alcohols to form alkenes.

Q93. Hydrides which are prepared by passing hydrogen gas over hot alkali metals or alkaline earth metals are called:

• A. Covalent hydrides
• B. Ionic hydrides✓
• C. Complex hydrides
• D. Metallic hydrides
• E. Polymeric hydrides

Explanation: The correct answer is Ionic hydrides. Ionic hydrides are formed when hydrogen gas is passed over hot alkali or alkaline earth metals (except Be and Mg). In this reaction, the metal donates electrons to hydrogen, resulting in a compound with ionic properties. These hydrides are typically white crystalline solids that react with water to release hydrogen gas.Covalent hydrides involve electron sharing with non-metals, which is not the case here. Complex hydrides involve more complex combinations of elements and are not formed by the simple interaction described. Metallic hydrides involve transition metals and are formed by hydrogen absorption into metal lattices, not applicable here. Polymeric hydrides involve hydrogen bonding in networks, not relevant to this reaction.

Q94. Dissolution of ammonium nitrate in water is an endothermic process. Which of the following graphs shows how the temperature alters as the ammonium nitrate is added to water and then the solution is left at room temperature?

• A. Option A
• B. Option B✓
• C. Option C
• D. Option D

Explanation: Since it is an endothermic process it takes heat from the surrounding making the temperature fall below room temperature. The temperature then gradually then goes back to room temperature.

Q95. For the reaction: N2 + 3H2 ⇌ 2NH3 The production of NH3 will be favored at:

• A. High pressure and catalyst
• B. Low pressure only
• C. Low pressure and catalyst
• D. High pressure only✓
• E. Catalyst only

Explanation: Increasing the pressure favors the side where the volume of gases is less. Since NH3 lies at the product side where total moles (volumes) of gases is 2 as compared to volume on the left side (reactant side) which 4. Increasing the pressure favors the NH3 production. Catalyst does not favor any side it increases the forward as well as the backward rate of reaction. Hence the answer is D.

Q96. s - sp3 overlap occurs in _ molecule.

• A. CI3
• B. CH4✓
• C. HF
• D. HI

Explanation: The methane molecule has four equal bonds. In hybridization, carbon's 2s and three 2p orbitals combine to form four identical orbitals, now called the 'sp3' hybrid orbitals. Each of them interacts with the 1s orbital of the Hydrogen atoms, forming a sigma bond, thus giving us methane.

Q97. According to the collision theory of bimolecular reactions in gas phase, minimum amount of energy is required for an effective collision is known as:

• A. Heat of reaction
• B. Rate of reaction
• C. Has no effect on the reaction
• D. Energy of activation✓

Explanation: The minimum energy required for an effective collision in a bimolecular gas-phase reaction is called the energy of activation.

Q98. Which is the only alkali metal that combines with nitrogen?

• A. Li✓
• B. Fr
• C. Cs
• D. K

Explanation: Answer: ALithium is the only alkali metal that reacts with nitrogen to form lithium nitride. This is amongst the peculiar properties of lithium.

Q99. Students calculated the cell voltage for the reaction, 𝐵𝑟2 + 2𝑁𝑎𝐶𝑙 ⟶ 2𝑁𝑎𝐵𝑟 + 𝐶𝑙2 through the formula 𝐸°𝑐𝑒𝑙𝑙= 𝐸°𝑟𝑒𝑑+ 𝐸°𝑜𝑥𝑑 the answer was negative. It means that:

• A. The reaction is non-spontaneous and feasible
• B. The reaction is non-spontaneous and not feasible✓
• C. The reaction is spontaneous and feasible
• D. The reaction is spontaneous and not feasible

Explanation: The energy associated with the separation/transfer of charge is the property of potential, E. A cell potential's arithmetic sign determines the spontaneity of the cell reaction, with positive values indicating spontaneous and feasible reactions and zero or negative values indicating nonspontaneous and non-feasible reactions (spontaneous in the reverse direction). If the value is positive, the oxidation-reduction reaction is spontaneous. Only spontaneous reactions are feasible. That is, without the assistance of a third party. The cathode undergoes reduction, while the anode undergoes oxidation. If the value is negative, it signifies that only the opposite reaction is spontaneous. It refers to the cathode's oxidation and the anode's reduction. The change in Gibbs free energy in a galvanic cell, where a spontaneous redox reaction drives the cell to produce an electric potential, must be negative. The cell potential, which is positive when electrons flow freely through the electrochemical cell, is the polar opposite of this.

Q100. Which of the following best describes the emission spectrum of atomic hydrogen?

• A. A discrete series of lines of equal intensity and equally spaced with respect to wavelength equally
• B. A series of only four lines
• C. A continuous emission of radiation of all frequencies
• D. Several discrete series of lines with both intensity and spacings between lines decreasing as the wavenumber increases with each series.✓

Explanation: The emission spectrum of atomic hydrogen has been divided into a number of spectral series, with wavelengths given by the Rydberg formula. These observed spectral lines are due to the electron making transitions between two energy levels in an atom. These lines have decreasing spacings(as shown below)

Q101. The compound ‘leaf alcohol’ is partly responsible for the smell of new - mown grass CH3CH2CH=CHCH2CH2OHLeaf alcoholWhich two compounds will be formed when ‘leaf alcohol’ is oxidized using hot, concentrated manganate (VII) ions?

• A. CH3CO2H and HOCH2CH2CH2CO2H
• B. CH3CO2H and HO2CCH2CH2CO2H
• C. CH3CH2CO2H and HO2CCH2CO2H✓
• D. CH3CH2CO2H and HOCH2CH2CO2H

Explanation: The answer is C as when the double bond breaks, based on the structure of both the carbons involved in the double bond, each having a hydrogen attached alongside an organic chain, aldehydes would be formed. Both the aldehydes would be oxidized to give carboxylic acid. CH3CH2COOH is formed plus COOHCH2CH2OH with the latter being a primary alcohol. It would be further oxidized to give a dicarboxylic acid which is HOOCCH2COOH, thus the answer is C.

Q102. The electrophilic reactions of Benzene are:

• A. Halogenation
• B. Nitration
• C. Sulphonation
• D. Alkylation and Acylation
• E. All of these✓

Explanation: Electrophilic substitution reactions of benzene involve the replacement of a hydrogen atom on the benzene ring with an electrophile. The listed reactions—halogenation, nitration, sulphonation, and Friedel-Crafts alkylation and acylation—are all examples of this process:Halogenation: Benzene reacts with halogens in the presence of a Lewis acid to form aryl halides.Nitration: Involves the substitution of a hydrogen atom by a nitronium ion to form nitrobenzene.Sulphonation: Benzene reacts with fuming sulfuric acid, introducing a sulfonyl group.Friedel-Crafts Alkylation and Acylation: Substitution of a hydrogen atom by an alkyl or acyl group with the help of a Lewis acid catalyst.All these reactions are characterized by the generation of an electrophile that attacks the π-electron-rich benzene ring, substituting one of the hydrogen atoms. Therefore, the correct answer is 'All of these.'

Q103. What is the unit of Kw for water?

• A. Moles/dm³
• B. Mol²/L²✓
• C. Dm³/moles
• D. Dm³/moles²

Explanation: Kw = [H+] [OH-]The unit for Kw would be:Kw = [mol/L] [mol/L]= mol2/L2

Q104. The greater the mass of gas taken, the greater will be the slope of a straight line. Because the greater the _greater be volume occupied.

• A. Pressure
• B. Temperature
• C. Number of moles✓
• D. All of these

Explanation: Option A is incorrect as greater pressure decreases the volume of a gas.Option B is incorrect as temperature increases so volume increases, however, the question is talking about the mass of the gas-only therefore the option is incorrect.Option C is correct as according to the formula n × 24 = Volume increasing the "number of moles" increases volume.

Q105. Alkaline earth metal hydroxides decompose on heating. Which of the following reactions is a correct representation of this decomposition?

• A. A✓
• B. B
• C. C
• D. D

Explanation: When heated, alkaline earth metal hydroxides undergo thermal decomposition to produce the corresponding metal oxide and water. The reaction can be represented as:M(OH)2(s) → MO(s) + H2O(l)where M represents an alkaline earth metal.For example, when magnesium hydroxide is heated, it decomposes to produce magnesium oxide and water:Mg(OH)2(s) → MgO(s) + H2O(l)

Q106. The reaction: Cl2 + H2O→ HCl + HOCl is an example of:

• A. Oxidation reaction
• B. Reduction reaction
• C. Auto-oxidation and reduction reaction✓
• D. Substitution reaction
• E. Addition reaction

Explanation: Auto-oxidation and reduction reaction is a reaction in which the same element is oxidized as well as reduced. In the reaction given above, the Cl element reduces to Cl-(HCl) and oxidizes to Cl+(in HOCl).

Q107. Nascent hydrogen used in the formation of methane is obtained from the reaction of:

• A. NaHCO3 with Zn
• B. HCl with Zn✓
• C. KOH with Zn
• D. H2O with Zn
• E. CH3I with Zn

Explanation: The correct option is the reaction of HCl with Zn. This reaction produces nascent hydrogen, which is a highly reactive form of hydrogen represented as [H]. This nascent hydrogen can then participate in further chemical reactions, such as the formation of methane. The balanced chemical reaction is: Zn + 2HCl → ZnCl2 + 2[H].Other options are incorrect because they do not involve reactions that produce nascent hydrogen. NaHCO3, KOH, H2O, and CH3I with Zn do not result in the generation of nascent hydrogen under typical conditions.

Q108. If the value of Kc is very large then it shows that _completed.

• A. Forward reaction✓
• B. Reverse reaction
• C. Equilibrium is maintained
• D. Kc is moderate

Explanation: Kc=[product]/[reactant], now if the Kc value is very large, we can use the equation to conclude that the concentration of products are higher than reactants, depicting that the forward reaction has completed or is near completion.

Q109. The catalyst used for the formation by dehydration of alcohols?

• A. Concentrated HN3 at 140 C
• B. Concentrated H2SO4 at 140 C✓
• C. Hot H3PO4 at 180 C
• D. ZnCl2 at 450 C

Explanation: Concentrated sulfuric acid is the catalyst which is used in this reaction.

Q110. Which property of the Group II elements (magnesium to barium) and their compounds increases with an increasing proton (atomic) number?

• A. The magnitude of the enthalpy change of hydration of the metal ion
• B. The pH of the aqueous chloride
• C. The solubility of the sulphate in water
• D. The stability of the carbonate to heat✓
• E. The tendency to form complex ions

Explanation: The stability of metal carbonates increases down the group, so D is the correct option. Down the group enthalpy change of hydration of metal ion, pH of the aqueous chloride, solubility of sulphate, and tendency to form complex ions decreases so options A, B, C, and E are wrong.

Q111. The diagram shows a galvanic cell. The current will flow from:

• A. Hydrogen electrode to copper electrode✓
• B. Copper electrode to hydrogen electrode
• C. Hydrogen electrode to HCl solution
• D. CuSO4 solution to hydrogen electrode

Explanation: Copper is less reactive than hydrogen so it should gain electrons.

Q112. What is the cell reaction ofZn(s) | Zn2+(aq) 1M | Ni2+(aq) 1M | Ni(s)Zn2+(aq) + 2e- -> Zn(s), Eo = -0.76 VNi2+(aq) + 2e- -> Ni(s), Eo = -0.25 V

• A. Ni2+ + Zn -> Zn2+ + Ni✓
• B. Zn2+ + Ni -> Ni2+ + Zn
• C. Zn2+ + Ni2+ -> Zn + Ni
• D. Zn + Ni -> Zn2+ + Ni2+

Explanation: In the given cell, Zn is oxidized to Zn2+ ions, and Ni2+ ions are reduced to Ni atoms. The anode is Zn, and the cathode is Ni. The electrons flow from the Zn electrode to the Ni electrode through the wire and the salt bridge. The overall reaction is: Zn(s) + Ni2+ (aq) → Zn2+ (aq) + Ni(s)

Q113. SiO2 is the only oxide that reacts with:

• A. HClaq
• B. KOHaq✓
• C. Steam
• D. SO3

Explanation: SiO2 is an acidic oxide and reacts with strong bases. Among the given options, it will react with hot, concentrated KOH(aq) due to the need for strong conditions to overcome its extensive covalent bonding. It does not react with HCl(aq) because it is not a base. It doesn't react with steam as the strong covalent network structure of SiO2 is too stable to break under such conditions. Lastly, SO3 is also an acidic oxide, and thus, does not react with another acidic oxide like SiO2.

Q114. The heat of combustion of hydrocarbon is very useful source of heat and power, considering the combustion reaction given below. CH4(g) +O2(g) →CO2(o) + 2H2O △H for the reaction is:

• A. △H = 213 kcal/mole✓
• B. △H = 231 kcal/mole
• C. △H = 426 kcal/mole
• D. △H = 312 kcal/mole

Explanation: The enthalpy of combustion of methane (CH4) is -890 kJ/mol. To convert this to kilocalories, use the conversion factor 1 kJ = 0.239 kcal. Therefore, -890 kJ/mol × 0.239 kcal/kJ = -212.715 kcal/mol, which rounds to approximately -213 kcal/mol. This makes Option A correct. The other options provide values that are not consistent with this conversion and the known enthalpy of combustion for methane.

Q115. Which of the following esters give a Jasmine Flavour?

• A. Ethyl Acetate
• B. Octyl Acetate
• C. Amyl Butyrate
• D. Benzyl Acetate✓

Explanation: Benzyl Acetate has a pleasant sweet aroma reminiscent of jasmine, and is used as a flavoring agent in jasmine or apple flavors to various cosmetics and personal care products like lotions, hair creams etc.

Q116. The only thing which can predict that if the reaction will be spontaneous or nonspontaneous is:

• A. Enthalpy change
• B. Free energy of the system✓
• C. Energy Change
• D. Temperature Change

Explanation: Free energy of the system also known as the Gibbs free energy determines if the reaction is spontaneous or not. The formula for Gibss free reaction = enthalpy change- T(entropy change).If Gibbs free reaction is 0 or less, then the reaction is spontaneous.

Q117. Which of the following does NOT belong to AB4 type molecule:

• A. H2S
• B. H2O
• C. SnCl2✓
• D. PH3

Explanation: SnCl2 does not belong to the AB4 group while the rest of the molecules belong to the AB4 group.H2O and H2S are AB 4 type molecules with two lone pairs. PH3 is an AB 4 molecule with one lone pair. SnCl2 is an AB 3 molecule with one lone pair and two bond pairs.

Q118. The strongest acid among the following is?

• A. Carbolic acid
• B. H2O
• C. Methanol
• D. Butanoic acid✓

Explanation: OPTION A: Carbolic acid is a weak organic acid with a pKa of around 10. It is a slightly acidic compound and is a weaker acid than water.OPTION B: Water is a neutral compound with a pH of 7, but it can act as a weak acid in certain solutions. This is due to the presence of Hydronium ions (H3O+) that form when water dissolves in acidic solutions.OPTION C: Methanol is a weak organic acid with a pKa of around 15. It is a weaker acid than water and phenol.OPTION D: Butanoic acid is a stronger organic acid with a pKa of around 4.5. It is a stronger acid than water, phenol, and methanol.

Q119. Which of the following will react with water?

• A. CHCl3
• B. Cl3CCHO✓
• C. CCl4
• D. ClCH2CH2Cl

Explanation: Cl3CCHO will react with water. Water is a polar solvent. Like dissolves like. A polar solvent will be dissolved in a polar and a non-polar compound will be dissolved in a nonpolar solvent. CCl4, ClCH2CH2Cl are non-polar. So they will not be able to dissolve in water. Cl3CCOOH will form hydrogen bonds with water due to which it will dissolve in water. Such hydrogen bonding is not present in the case of CHCl3. Chloral (Cl3CCHO) reacts with water to form chloral hydrate, CCl3CH(OH)2

Q120. For a chemical reaction to occur, particles that collide should:

• A. All of these✓
• B. Have proper orientations
• C. Have proper energies
• D. Be in a homogenous mixture

Explanation: The collision theory states that for particles to take part in a chemical reaction, they must collide with one another, have sufficient energies, proper orientation, and should be in a homogenous mixture.

Q121. If we balanced the following reaction , what is the net ionic charge on the right side of the equation?_H+ +_ MnO4- + _ Fe2+ →_ Mn2+ + _ Fe3+ + _ H2O

• A. +5
• B. +7
• C. +10
• D. +17✓

Explanation: The correct option is '+17'.This will be balanced using the ion-electron method. Calculate the net charge on the RHS of the equation which should be the same for the LHS. The net ionic charge on either side must be zero for the equation to be balanced.

Q122. If a molecule MX3 has zero dipole moment, the sigma bonding orbitals used by M are:

• A. Pure p
• B. sp hybrids
• C. sp2 hybrids✓
• D. sp3 hybrids

Explanation: In order for MX3 molecule to have zero dipole moment, it must have a symmetrical shape which in this case can only be trigonal planar. The bond angle in this case between X-X would be 120o so it should have sp2 hybrids.

Q123. In the following reaction sequence, product D will be:

• A. 1 - propanol
• B. Propanoic acid
• C. 2 - propanol✓
• D. Mixture of methanol and ethanol

Explanation: The above reaction scheme describes dehydrohalogenation of the alkyl halide into an alkene, followed by hydration of the alkene. The first step involves the reaction of propyl bromide with alcoholic KOH, which will result in elimination or dehydrohalogenation, whereby the halogen atom and adjacent carbon atom's hydrogen atom is removed, resulting in the formation of a double bond between the two carbons, forming propane, which is product C. Propene is acted upon by aqueous H2SO4, which implies hydration or addition of H2O, resulting in the formation of two products; the major product which is 2-propanol and the minor product which is 1-propanol so, the major product is the preferred option, i.e. option C.

Q124. In which of the following cases are the benzene rings isolated?

• A. Naphthalene
• B. Phenanthrene
• C. Anthracene
• D. Triphenylmethane✓

Explanation: The structure of Triphenylmethane is as follows:

Q125. 1,4-dimethyl benzene is called as _.

• A. Ortho-xylene
• B. Para-xylene✓
• C. Para-methyl toluene
• D. Meta-methyl toluene

Explanation: Xylene is any of three organic compounds with the formula (CH₃)₂C₆H₄. They are derived from the substitution of two hydrogen atoms with methyl groups in a benzene ring. In ortho benzene, the two methyl substituents bonded to adjacent carbon atoms of a benzene ring i.e. carbon no. 1 and 2. In para-xylene, one methyl group is at position 1 and other at 4.

Q126. The solubility product of AgCl is 2.0x10-10 mol-2 dm-6. The maximum concentration of Ag+1 ions in the solution is:

• A. 2.0x10-12 mol dm-3
• B. 1.41x10-5 mol dm-3✓
• C. 1.0x10-12 mol dm-3
• D. 2.5x10-10 mol dm-3

Explanation: To find the maximum concentration of Ag+ ions in a solution of AgCl, we consider the dissolution process: AgCl(s) → Ag+(aq) + Cl-(aq). The solubility product expression is given by Ksp = [Ag+][Cl-]. Since the stoichiometry indicates that one mole of AgCl produces one mole of Ag+ and one mole of Cl-, we can denote their concentrations as [Ag+] = [Cl-] = s, where 's' represents solubility in mol dm-3. Thus, Ksp = s². Given Ksp = 2.0 x 10-10 mol2 dm-6, we can solve for 's': s² = 2.0 x 10-10, leading to s = √(2.0 x 10-10) ≈ 1.41 x 10-5 mol dm-3, which represents the maximum concentration of Ag+ ions.The other options are incorrect because they either stem from miscalculations or a misunderstanding of how to apply the Ksp expression and stoichiometry involved in the dissolution of AgCl.

Q127. The rate constant of a first-order reaction is 3 x 10-6 per second. If the initial concentration is 0.10 M, the initial rate of reaction is:

• A. 3 x 10-3 Ms-1
• B. 3 x 10-4 Ms-1
• C. 3 x 10-6 Ms-1
• D. 3 x 10-7 Ms-1✓

Explanation: Rate constant of the first order reaction (K) = 3 x 10-6 per sec and initial concentration [A] = 0.10 M. We know that initial rate constant:K[A] = 3 x 10-6 x 0.10 = 3 x 10-7 Ms-1

Q128. Identification tests for functional groups of organic compounds are associated with specific observations. Tollen’s reagent is an ammoniacal silver nitrate solution, which is used for the identification of a functional group X with an observation O. Identify X and O.

• A. X = Aldehyde O = Silver mirror✓
• B. X = Ketone, O = Grey precipitate
• C. X = Ketone, O = Silver mirror
• D. X = Aldehyde O = Red precipitate

Explanation: Tollens reagent test is also known as the silver mirror test. It cannot react with ketones but it reacts with aldehydes, thereby identifying the aldehyde functional group. Upon reacting, the silver precipitates as a silver mirror which coats the bottom of the test tube. Hence, option A is the correct answer as it is the only one with both correct functional group and observation.

Q129. Benzene can be prepared from:

• A. From Petroleum
• B. From Coal
• C. From Acetylene
• D. From Phenol
• E. All of these✓

Explanation: The correct answer is that benzene can be prepared from all the mentioned sources. Petroleum: Benzene is obtained through catalytic reforming and steam cracking of naphtha, which are standard industrial processes for hydrocarbon refinement. Coal: During the carbonization of coal, benzene is one of the volatile compounds distilled from coal tar. Acetylene: Acetylene undergoes cyclic polymerization at high temperatures, forming benzene as a result. Phenol: Reduction of phenol using zinc dust is another chemical method to synthesize benzene, with zinc oxide as a byproduct. Thus, each method demonstrates a valid approach to benzene production.

Q130. Choose the right molecule.

• A. CH3
• B. CO
• C. H2O
• D. NH3✓

Explanation: Standard structural formula of Ammonia

Q131. The enthalpy change of the reaction H2(g) + ½ O2 -> H2O (l) under standard conditions is:

• A. Enthalpy change of formation of water
• B. Enthalpy change of neutralization
• C. Both; Enthalpy change of combustion of Hydrogen and enthalpy change of formation of water✓
• D. Enthalpy change of combustion of Hydrogen

Explanation: Since 1 mole of H2 is being combusted, it can be called enthalpy change of combustion of H2. Also, 1 mole of water is being formed from its constituent elements under standard state so it can also be called standard enthalpy change of formation of water.

Q132. The method which is used on an industrial scale for production of alcohol from alkene is:

• A. Hydrohalogenation of alkenes
• B. Dehydration of alkenes
• C. Hydration of alkenes✓
• D. Hydroxylation of alkenes

Explanation: Option A: Gives alkyl halide, by breaking a double bond followed by the electrophilic addition of hydrogen and halogen. Option B: Alkenes can not be dehydrated. Option C: Alkenes, upon reaction with protic acids and other catalysts, tend to gain a molecule of H2O to form Alcohol, hence Option C is correct. Option D: Hydroxylation of alkene is a process in which the alkene is converted to glycol.

Q133. For a sub shell I=2 and m = -2,-1,0,+l,+2,it implies that it has _ space orientation.

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

Explanation: Option D is correct as the subshell with l=2 is the d subshell with "5" orbitals.

Q134. Which of the following compounds react slower than benzene in electrophilic substitution reaction?

• A. Nitrobenzene✓
• B. Phenol
• C. Aniline
• D. Toluene

Explanation: An electrophilic substitution reaction is a chemical process in which a compound's functional group is replaced by an electrophile. In this case, the displaced group is a hydrogen atom.The derivatives of benzene which have activating groups attached push electron density towards the ring, making it more susceptible to electrophilic attack and consequently, more rapid reactions.Similarly, the derivatives of benzene which have a deactivating group attached withdraw electron density away from the ring, making it less susceptible to electrophilic attack and consequently, slower reactions. Nitrobenzene is an example of such a derivative which is less reactive than benzene because the nitro group is a deactivating group (meta-directing). Therefore, option A is the correct answer.The table below lists some common groups and whether they are activators/deactivators and ortho para/meta directing.

Q135. X is a salt that decomposes in water. What is the reason for its decomposition? e- + X3+ → X2+ E cell = 1.91 V

• A. This potential oxidises salt
• B. This potential reduces salt✓
• C. This potential reduces water
• D. This potential oxidises water

Explanation: Reduction is can be defined as gain of electrons. Since the salt is gaining an electron, it is being reduced.

Q136. When Gypsum is heated to about 100° C, it losses some water of crystallization and becomes:

• A. Epsom salt
• B. Kieserite
• C. Plaster of Paris✓
• D. Bleaching Powder
• E. Caustic soda

Explanation: When gypsum (calcium sulfate dihydrate) is heated to approximately 373 K (100°C), it loses part of its water of crystallization, resulting in the formation of calcium sulfate hemihydrate, commonly known as Plaster of Paris. This transformation is unique to gypsum and its chemical composition. The other options, such as Epsom salt, kieserite, bleaching powder, and caustic soda, are chemically distinct and do not undergo similar transformations when heated. Epsom salt and kieserite are magnesium-based compounds, while bleaching powder and caustic soda are used for entirely different purposes.

Q137. If the nuclear radius of Al27 is 3.6 fm, the approximate nuclear radius of Cu64 in fermi is

• A. 1.2 fm
• B. 2.4 fm
• C. 3.6 fm
• D. 4.8 fm✓

Explanation: Explanation is given below.Nuclear radius, R = RoA1/3 where Ro is a constant and A is the mass number So, r Al/r Cu = A Al^⅓/ACu⅓ = 27⅓/64⅓ =4/3 Thus r Cu​ =4/3×3.6=4.8 Fermi

Q138. In "Down Cells", the cathode is made up of:

• A. Graphite
• B. Copper
• C. Iron✓
• D. Inert material

Explanation: The Downs process is a method for the commercial preparation of metallic sodium, in which molten NaCl is electrolyzed in a special apparatus called the Downs cell.The Downs cell uses a carbon anode and an iron cathode.Hence, C is the correct option.

Q139. Which step should be repeated over and over to get a variety of substituted products?

• A. None of these
• B. Termination
• C. Propagation✓
• D. Initiation

Explanation: Radical chain reactions have three distinct phases: initiation, propagation, and termination. The initiation phase describes the step that initially creates a radical species. The propagation phase describes the ‘chain’ part of chain reactions. Once a reactive free radical is generated, it can react with stable molecules to form new free radicals. These new free radicals go on to generate yet more free radicals, and so on. This step, therefore, gives a variety of substituted products. The termination phase occurs when two free radical species react with each other to form a stable, non-radical adduct.

Q140. When a body of weight ‘W’ is kept suspended by a string, the weight of the body pulls the string downwards, while the string pulls the body upwards with an equal force, this force is called?

• A. The frequency of the string
• B. The displacement of the string
• C. The tension in the string✓
• D. The wavelength of the string

Explanation: When a body is suspended by a string, the downward gravitational force (weight) is balanced by an upward force called tension. This tension is equal in magnitude to the weight of the body, keeping the system in equilibrium. The incorrect options (frequency, displacement, wavelength) all pertain to aspects of wave motion and vibrations, which are unrelated to the static equilibrium scenario described in the question.

Q141. Law of conservation of momentum states that:I. there is no external force applied to a system, then the total momentum of that system remains constant II. if there is an external force applied to a system, then the total momentum of that system remains constant III. if there is no external force applied to a system, then the total momentum of that system keeps changing

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

Explanation: If there is no external force applied to the system, then the total momentum of that system remains constant. If an external force is applied then the total momentum will change.The law of conservation of momentum states that, for two or more bodies in an isolated system acting upon each other, their total momentum remains constant unless an external force is applied. Therefore, momentum can neither be created nor destroyed and will stay constant.

Q142. What will happen in a time of 7 hours, if a radioactive substance has an average life of 7 hours?

• A. Half of the active nuclei decay
• B. Less than half of the active nuclei decay
• C. More than half of the active nuclei decay✓
• D. Total nuclei decay

Explanation: The average life of a radioactive substance is the reciprocal of the decay constant, and it is longer than the half-life. The half-life is the time taken for half of the radioactive nuclei to decay. In the given scenario, the time duration is equal to the average life, which means more than half of the radioactive nuclei would have decayed. Option C is correct because it accurately reflects the decay amount over the average life span. Option A is incorrect because it describes the half-life scenario, not the average life. Option B is incorrect as it underestimates the decay, and Option D is incorrect because not all nuclei will decay in this time frame.

Q143. A 220 V main supply is connected to a resistance of 100 k ohms. The effective current is _.

• A. 2.2mA✓
• B. 2.2/v2 mA
• C. 2.2 x v2 mA
• D. None of the above

Explanation: We know that,V = IRI = VRI = 220V/100k.ohmI = 2.2 mA

Q144. Consider a car is travelling for one hour. In which of the following cases is the average velocity zero?

• A. The car travels 20 km due east.
• B. The car travels 60 km due east, then turns around and travels 40 km due west.
• C. The car travels 70 km due east.
• D. The car travels 30 km due west, then turns around and travels 30 km due east.✓

Explanation: We know that average velocity = total displacement/total time.The car travels 30 km due west, then turns around and travels 30 km due east.Since displacement is a vector quantity and needs direction.Let's assume that positive displacement is towards the west and negative displacement is towards the east.Therefore:Average Velocity = +30 + (-30)/1= 0/1= 0 km/hr.

Q145. The values of electric intensity will _ due to the presence of dielectric medium:

• A. Increase
• B. Increase exponentially
• C. Decrease✓
• D. Remain same

Explanation: The strength of the electric field is reduced due to the presence of dielectric. If the total charge on the plates is kept constant, then the potential difference is reduced across the capacitor plates.

Q146. The centripetal acceleration is maximum when radius r is:

• A. Increasing
• B. Decreasing✓
• C. Constant
• D. None of these options are correct

Explanation: We know that centripetal acceleration (a) = v2/r where v is the linear speed and r is the radius. If v is constant, then a is inversely proportional to r. So, a will be maximum when r is decreasing.

Q147. The angular measurement is known as _ measurement.

• A. Parameter
• B. Area
• C. Circumference✓
• D. All of these

Explanation: The correct answer is 'Circumference' because angular displacement (θ) is calculated as the arc length (S) divided by the radius (r) of the circle, expressed in the formula θ = S/r. This shows that angular measurement is directly related to the arc length, which is a segment of the circumference. The other options, 'Parameter' and 'Area', do not pertain to this specific calculation as they refer to different concepts and do not describe the relationship between angular displacement and circular measurements.

Q148. How fast an H+ ion should move in magnetic field 2.5x10-3 T such that magnetic force equal its weight?

• A. 6 x 10-5 m/s
• B. 4.5 x 10-5 m/s
• C. 3.3 x 10-6 m/s
• D. 4 x 10-5 m/s✓

Explanation: According to given conditionForce = WeightevB = mgv = mg/eBPutting the values, we obtain

Q149. What is an optically active medium?

• A. A medium which absorbs light
• B. A medium which absorbs polarized light
• C. A medium which can rotate the plane of polarization✓
• D. A medium which refracts polarized light

Explanation: An optically active medium can rotate the plane of polarization of a beam of light that is passed through it.

Q150. When a car travelling with constant velocity passes a stationary observer, the observer hears a change in the frequency of sound emitted by the car. Which statement is correct ?

• A. The change in frequency is greater as a car moves away than as it approaches.
• B. The greater the speed of the car, the greater the change in observed frequency.✓
• C. The observed frequency is lower as the car moves toward the observer and higher as the car moves away from the observer
• D. The volume of the sound heard by the observer does not change as the car approaches.

Explanation: Wave speed is the distance a wave travels in a given amount of time, such as the number of meters it travels per second. Wave speed is related to wavelength and wave frequency by the equation: Speed = Wavelength x Frequency so as the speed increases the observed frequency also increases.

Q151. Faraday law states that the rate of change of magnetic flux is equal to:

• A. Electromotive force✓
• B. Induced current
• C. Induced flux
• D. Induced magnetic field

Explanation: Faraday's law of induction states that the rate of change of magnetic flux is equal to the induced electromotive force (EMF). The induced EMF is the voltage that is produced in a circuit by a changing magnetic field.The mathematical expression for Faraday's law is:ε = -dΦB/dt where:ε is the induced EMF in voltsΦB is the magnetic flux in webersd/dt is the rate of change with respect to timeThe negative sign in the equation means that the induced EMF is in the direction that opposes the change in magnetic flux.The induced EMF can cause an induced current to flow in the circuit. The magnitude of the induced current is proportional to the induced EMF.The induced magnetic field is the magnetic field that is produced by the induced current. The magnitude of the induced magnetic field is proportional to the induced current.So, the answer is electromotive force.

Q152. A row of 25 decorative lights, connected in series, is connected to a main transformer. When the supply is switched on, the lights do not work. The owner uses a voltmeter to test the circuit. When the voltmeter is connected across the third bulb in the row, a reading of zero is obtained. Which of the following cannot be the only fault in the circuit?

• A. The filament of one of the other bulbs has broken
• B. The filament of the third bulb has broken.✓
• C. The fuse in the mains transformer has blown.
• D. There is a break in the wire from the supply to the transformer.

Explanation: When a filament of a bulb in a series circuit is broken, it creates an open circuit causing the voltage to be maximum across that bulb. In this case, the third bulb's broken filament would result in a high voltage reading, not zero. The correct answer is that the filament of the third bulb has broken. This creates an open circuit, leading to the absence of current flow and hence zero voltage. The other options are incorrect because they do not explain the observed zero voltage across the third bulb.

Q153. Laplace's correction to Newton’s formula is based on the fact that the compressions and rarefactions occur as _.

• A. Adiabatic process✓
• B. Isothermal process
• C. Isochoric process
• D. Isobaric process

Explanation: Laplace's correction to Newton’s formula recognizes that sound waves involve rapid compressions and rarefactions where there is insufficient time for heat exchange with surroundings, making the process adiabatic. Newton's original assumption of an isothermal process (constant temperature) was incorrect because it fails to consider the rapid temperature changes accompanying pressure variations in sound waves.The adiabatic process assumption accounts for these temperature changes, leading to a more accurate formula for sound speed in gases. The other processes—isochoric (constant volume) and isobaric (constant pressure)—do not describe the conditions experienced during sound wave propagation.

Q154. A parachutist is falling constant terminal velocity. Which statement is not correct?

• A. Gravitational potential energy is converted into kinetic energy of the air.
• B. Gravitational potential energy is converted into kinetic energy of the parachutist.✓
• C. Gravitational potential energy is converted into thermal energy of the air
• D. Gravitational potential energy is converted into thermal energy of the parachutist.

Explanation: Terminal velocity reaches when the force of gravity acting on the object is equal to the air resistance or viscous force of air on the body. Air resistance is a major factor contributing in a falling object to reach terminal velocity as it can easily contribute to the speed at which the body thus both kinetic energy and potential energy cannot be equated.

Q155. During radioactive decay of a nucleus zXA, β emission takes place along with the daughter nucleus. Because of this beta particle emission, the mass number (A) of the parent nucleus:

• A. Remains constant✓
• B. Decreases by 1
• C. Increases by 1
• D. Decreases by 2

Explanation: On emitting a β particle the number of nucleons in the nucleus (i.e. protons and neutrons) remains same, but the number of neutrons is decreased by one and the number of protons is increased by one.If a radioactive nucleus P with mass number A and atomic number Z emits a beta particle to form a daughter nucleus Q with mass number A and atomic number Z+1.(a) Atomic number Z is not conserved. It is increased by 1.(b) Mass number A is conserved.Result: So, from the above discussion it is clear thwt mass number (A) remains constant after the beta decay and not increased or decreased .

Q156. The earth rotates on its axis once a day. Suppose, by some process the earth contracts so that it’s radius is only half as large as at present, then how long the earth will take to complete it’s rotation?

• A. 24 hours
• B. 18 hours
• C. 6 hours✓
• D. 12 hours

Explanation: Here we assume that the mass of earth remains the same, moment of the inertia of the earth rotating about its axis is :I=⅖ MR^2-------eq1Angular velocity of the earth is:ω=2pi/T-------eq 2When the radius is reduced to half, The new moment of inertia isI=2/5MR^2=2/5M(R/2)^2----eq3New time period is T’ an angular velocity is:ω’=2pi/T’Applying the law of conservation of angular momentum, we get:Iω=I’ω’From eq 1,2,3, and 4 we get(2/5MR^2)*(2pi/T)=[2/5M(R/2)^2]*(2pi/T’)->T’=T/4But T=24 hrsT=24/6=6 hrs

Q157. A sphere of charge +Q is fixed in a position. A smaller sphere of +q is placed near the larger sphere and released from the rest. The small sphere will move away from the large sphere with?

• A. Decreasing velocity and decreasing acceleration
• B. Decreasing velocity and increasing acceleration
• C. Decreasing velocity and constant acceleration
• D. Increasing velocity and decreasing acceleration✓
• E. Increasing velocity and increasing acceleration

Explanation: When two spheres with like charges are placed near each other, they exert a repulsive force on one another. The small sphere with charge +q experiences a repulsive force due to the stationary sphere with charge +Q, causing it to move away. According to Coulomb's Law, this force is given by: F = kQq/r² where r is the distance between the charges. As the sphere moves away, the distance r increases, causing the force and consequently the acceleration to decrease. However, the velocity of the small sphere continues to increase because it is still under the influence of a repulsive force—albeit a diminishing one. Thus, the correct answer is Option D: Increasing velocity and decreasing acceleration. The other options incorrectly describe either the velocity or the acceleration as decreasing or constant, which does not align with the physical principles governing the motion of charged particles under electrostatic forces.

Q158. A standing-wave pattern is formed when the length of the string is:

• A. an odd multiple of quarter wavelength
• B. an integral multiple of quarter wavelength
• C. an integral multiple of wavelength
• D. an integral multiple of half wavelength✓

Explanation: A standing wave pattern is formed when the length of the string is an integral multiple of half wavelength.

Q159. A metal cube with sides of length “𝑎” has electrical resistance 𝑅 between opposite faces. What is the resistance between the opposite faces of a cube of the same metal with sides of length 3𝑎?

• A. 9𝑅
• B. 3𝑅
• C. R/3✓
• D. 𝑅/9

Explanation: the resistance can be found by the relation R=pL/A p(resistivity) In this case L=a and A=a2 soR=p 1/aWhen L=3a then A=9a2So R=p 1/3a Hence 1/3 times

Q160. A constant force F= 2i + 3j +4k is applied on a body. What will be the work done to move the body 5m in the z-direction?

• A. 0
• B. 10 J
• C. 45 J
• D. 20 J✓

Explanation: We know that work done = F x dwhere F is the force and d is the displacement in the direction of the force.The question statement says a constant force, F = 2i + 3j + 4k is applied. The component of force in the z-direction (direction of displacement of the body) = 4NTherefore, Work done = 4 x 5This equals to 20 J.

Q161. In the case when the electrons lose all their kinetic energy (K.E.) in the first collision, the X-ray photon emitted has the following set of frequency and wavelength?

• A. fmax , λmin✓
• B. fmax , λmax
• C. fmin , λmax
• D. fmin , λmin

Explanation: fmax , λmin : This option suggests that when electrons lose all their kinetic energy in the first collision, the emitted X-ray photon will have maximum frequency ( fmax ) and minimum wavelength ( λmin ). According to the relationship between frequency and wavelength (c = λf, where c is the speed of light), as frequency increases, wavelength decreases. So, if the frequency is maximum, the wavelength should be minimum, and vice versa.

Q162. If a charged particle moves through a magnetic field perpendicular to it, _.

• A. Both momentum and energy of particle change
• B. Momentum as well as energy are constant
• C. Energy is constant but momentum changes✓
• D. Momentum is constant but energy changes

Explanation: If a charged particle moves through a magnetic field perpendicular to it, it acquires circular motion. During circular motion, the velocity of the body changes at each point. As momentum depends upon the velocity, by the equation, P = mv, the momentum also changes with the velocity. Only the direction of the velocity is changing, whereas its magnitude remains constant. From the equation of Kinetic energy, K.E = ½ mv², it is evident that the square of the velocity means no change in magnitude.

Q163. In the diagram below, the displacement of an oscillating particle is plotted against time. What does the length ‘PR’ on the time axis represent?

• A. Twice the frequency
• B. Half the period✓
• C. Half the frequency
• D. Twice the period

Explanation: The time period of the wave is the time between two consecutive troughs or two consecutive crests. In the given diagram you can see the distance between a trough and a crest which means its half a period.

Q164. A particle having mass m and momentum p, the kinetic energy of the particle is given by:

• A. p^2/m
• B. p/m
• C. p^2/(2m)✓
• D. m^2/p

Explanation: We know that:P=mv From here v=p/mWe know know that K.E=0.5mv^2K.E=0.5m(p/m)=p^(2/2m)

Q165. The following question belongs to the topic of momentum:

• A. Current
• B. Length
• C. Angular momentum✓
• D. Torque
• E. Displacement

Explanation: The correct answer is Angular momentum. In three-dimensional space, the angular momentum of a point particle is defined as the cross product of its position vector (r) with respect to a given origin and its linear momentum vector (p). This forms a pseudovector, which is essential in describing rotational motion in physics. The other options are incorrect because they do not correctly describe the properties or definitions related to momentum or angular momentum. 'Current' relates to electric charge flow, 'Length' and 'Displacement' relate to measures of distance, and 'Torque' is a measure of rotational force, not a type of momentum.

Q166. If a car collides with a housefly, what will be the magnitude of the force experienced by the housefly?

• A. Much greater than the force experienced by the car
• B. Much lesser than than the force experienced by the car
• C. Same as the force experienced by the car✓
• D. 10 times less than the force experienced by the car

Explanation: Yes, the same amount of force is imparted on each of them at the moment of the collision. However, one is affected much more than the other.Instead of thinking in terms of accelerating cars and flies, assume each has a constant velocity. At the moment of impact, each of them undergoes an acceleration (in the negative direction, so we usually call it deceleration) proportional to the force F of the impact. F is the same for both objects.Now, according to Newton's third law, at the moment of impact, the force that the car imparts on the fly is exactly equal to the force that the fly imparts on the car. Also, according to Newton's second law, the force is equal to mass times acceleration. As such, the train hits the fly with a massive amount of force, equal to the acceleration times the mass of the train.Results:The magnitude of force experienced by the housefly is the same as that experienced by the car neither less nor more because Newton's 3rd law is applicable here.

Q167. Time varying magnetic field creates electric field, this is called --------

• A. Electric induction
• B. Magnetic induction
• C. Electromagnetic induction✓
• D. Dipole induction

Explanation: Option C is correct since electromagnetic induction is a process in which a conductor is put in a particular position and the magnetic field keeps varying or the magnetic field is stationary and a conductor is moving. This produces a Voltage or EMF (Electromotive Force) across the electrical conductor.

Q168. Internal resistance of a battery is _ ohm if E = 10V , V = 9V, I = 1A

• A. 1✓
• B. 0.1
• C. 0.01
• D. None of these

Explanation: We know that E = V + Ir Where r is the internal resistance. Subsituting the values in the formula: 10 = 9 + 1r 1 = 1r r = 1 ohm

Q169. When a charged particle is projected perpendicular to a magnetic field:

• A. Its path is circular in a plane perpendicular to the plane of magnetic field✓
• B. The speed and kinetic energy of the particle remains constant
• C. The velocity and momentum of the particle changes only in direction
• D. The time period of revolution, angular and frequency of revolution is independent of velocity of the particle and radius of circular path

Explanation: When a charged particle is projected perpendicular to a magnetic field, The path of particle is circular in a plane perpendicular to the plane of magnetic field. The correct option is A.

Q170. The sound waves of frequency more than 20 khz are termed as:

• A. Supersonic
• B. Audible
• C. Infrasonic
• D. Ultrasonic✓

Explanation: Ultrasonic waves are sound waves whose frequencies are higher than those of waves normally audible to the human ear. ultrasonics, vibrations of frequencies greater than the upper limit of the audible range for humans—that is, greater than about 20 kilohertz.

Q171. Michelson's interferometer is an instrument that can be used to measure _.

• A. Speed
• B. Frequency
• C. Distance✓
• D. Amplitude

Explanation: Option C is correct since the distance is measured by the wavelength of the light. Options A, B, and D are incorrect since the device failed to measure the speed of light, whereas frequency and amplitude cannot be measured.

Q172. If a charged particle is at rest but we are seeing it from a train then we observe _.

• A. Electric field
• B. Magnetic field
• C. Both fields✓
• D. None of these

Explanation: If a charged particle is at rest and you are observing it from a moving train, the observer on the train will not see any magnetic field generated by that charged particle. This is because a stationary charged particle only produces an electric field, not a magnetic field.However, if the observer is moving relative to the charged particle, they will experience a magnetic field due to the motion of the observer through the electric field created by the stationary charge. In other words, the magnetic field is only observed in relation to the motion of the observer or other charges.

Q173. A wave passes through a medium, each particle of the medium performs 100 complete vibrations in 5 seconds. What is the frequency of the wave?

• A. 2 Hz
• B. 20 Hz✓
• C. 4 Hz
• D. 40 Hz

Explanation: The following is the solution:Frequency is the number of complete oscillations in 1 second.We know that:the number of complete oscillations in 5 seconds is 100the number of complete oscillation in 1 second is xTherefore: x = 100/5 = 20Hz

Q174. The Lenz's law refers to:

• A. Induced current✓
• B. Induced potential
• C. Motional emf
• D. All of these

Explanation: 'The induced electromotive force', with different polarities, induces a current whose magnetic field opposes the change in magnetic flux, through the loop, in order to ensure that original flux is maintained, through the loop, when current flows in it.Since, Lenz's law discusses the electric current induced in a conductor, this option is incorrect.

Q175. A particle, carrying a charge of 5e, falls through a potential difference of 25 V. What would be energy acquired by the particle in ‘J’.

• A. 1.6 x 10-19 J
• B. 125 J
• C. 125 x 10-19 J
• D. 125 x 1.6 x 10-19 J✓

Explanation: Electric Potential Energy = Electric Potential x ChargeCharge = 5 x 1.6 x 10-19 CElectric Potential Energy = 25V x (5 x 1.6 x 10-19) CThis could be manipulated to give us (125 x 1.6 x 10-19) J, which is Option D.

Q176. If the velocity of a charged particle and magnetic field are at a fixed angle that is not 90 degrees, then the path will be:

• A. Circular
• B. Straight line
• C. Spherical
• D. Helical✓

Explanation: Force is given by F = qvBsinθ, where F, q, v and B are the force, charge on particle, velocity of particle and magnetic field strength respectively. θ is the angle between v and B.If θ = 0 or 180, there is no force on the particle and it continues to move with uniform velocity.If θ = 90, the force acting on the particle is maximum and perpendicular to the path of the particle. (force acts as a centripetal force and the particle moves along a circular path)When θ has a value other than 0, 90 or 180, the direction of velocity is either perpendicular or parallel to B. If the component of velocity is parallel to B it will not be affected by the magnetic field. However if the component of velocity is perpendicular to B it will be subject to a force of the magnetic field which would result in uniform circular motion. Hence the particle would have a component along a straight line as well as a circular component. Therefore the path would be in the form of a helix. And so option D is correct.

Q177. When a charge experience a force, there will be a _ field developed.

• A. Magnetic
• B. Electric✓
• C. Static
• D. All of these options are correct
• E. Both A and B

Explanation: The correct answer is Electric (Option B). An electric field is created around a charge, and when that charge experiences a force, it is due to the influence of this electric field. A magnetic field, on the other hand, is produced by moving charges, and therefore does not apply in this context. 'Static' refers to charges that are not in motion, and while they can create electric fields, the question specifically relates to the force experienced by a charge. Thus, the other options do not accurately reflect the relationship between force and the fields generated by charges.

Q178. If electrons of charge ‘e’, with rest mass ‘m’, are accelerated through a potential difference ‘V’ and strike a metal target, then velocity of electrons is:

• A. Ve/m
• B. √(Ve/m)
• C. √(Ve/)2m
• D. √(2Ve/m)✓

Explanation: √(2Ve/m): This option suggests that the velocity of electrons is the square root of twice the potential difference (2V) divided by the rest mass (m). This option introduces a factor of 2 in the numerator, which is incorrect based on the equation for velocity.Based on the correct equation, the velocity of electrons accelerated through a potential difference (V) can be calculated using the formula:velocity = √(2eV/m)Therefore, the correct answer is option d) √(2Ve/m).Please note that 'e' represents the charge of an electron, 'm' represents the rest mass of an electron, and 'V' represents the potential diffe√(2Ve/m): This option suggests that the velocity of electrons is the square root of twice the potential difference (2V) divided by the rest mass (m). This option introduces a factor of 2 in the numerator, which is incorrect based on the equation for velocity.Based on the correct equation, the velocity of electrons accelerated through a potential difference (V) can be calculated using the formula:velocity = √(2eV/m)Therefore, the correct answer is option d) √(2Ve/m).Please note that 'e' represents the charge of an electron, 'm' represents the rest mass of an electron, and 'V' represents the potential difference.

Q179. If the magnitude of charges on two point objects is doubled and the distance between them is also doubled, then force will be: ...

• A. Two times
• B. Four times
• C. Unchanged✓
• D. Halved

Explanation: Initially, the force between charges say q1​ and q2​ seperated with distance r is :F=4πϵ0​1​r2q1​q2​​ Step 2: New force calculationWhen the charge is doubled and the distance between charges is also doubled, i.e q1′​=2q1​,q2′​=2q2​,r′=2r The new force will be : F′=4πϵ0​1​r′2q1′​q2′​​ F′=4πϵ0​1​(2r)2(2q1​)(2q2​)​=4πϵ0​1​r2q1​q2​​=F Hence, the force will remain the same

Q180. The speed of sound through a gas is measured as 340 m/s at pressure P1 and temperature T1. What will be the speed of sound if the pressure of a gas is doubled but the temperature is kept constant?

• A. 342 m/s
• B. 340 m/s✓
• C. 170 m/s
• D. 680 m/s

Explanation: According to laplace equation v=√(γP/p), the pressure and velocity are directly related however if the pressure is doubled then density would also double naturally, so the speed of sound would remain the same.

Q181. Two capacitors C1 (6μF) and C2(12μF) are in series across a 180 volts d.c. supply. Calculate the potential difference across each capacitor (C1 and C2).

• A. 98 volts ... 32 volts
• B. 120 volts ... 60 volts✓
• C. 68 volts ... 96 volts
• D. 30 volts ... 65 volts
• E. 25 volts ... 25 volts

Explanation: Since the voltage is INVERSELY proportional to the capacitance, according to the formula: Q=CV, the voltage division is also in the same way. Since the capacitance ratio is 1:2, the voltage division is 2:1. Hence the correct division of 180V voltage will be 120 V and 60V.

Q182. A body performing circular motion with a constant speed has a constant:

• A. Momentum
• B. Angular velocity✓
• C. Acceleration
• D. Radius vector

Explanation: A body moving along a circular path moves such that it traverses equal arc-length in equal intervals of time. Displacement, velocity and acceleration changes at each point on the trajectory. Hence, the speed is uniform and consequently the angular velocity is constant.

Q183. What is NOT true of 2 forces that give rise to a couple?

• A. They act in opposite directions
• B. They both act at the same point✓
• C. They both act on the same body
• D. They both have the same magnitude

Explanation: Two equal and opposite parallel forces not acting along the same line form a couple.

Q184. In the case of a harmonic oscillator total energy remains:

• A. Variable
• B. Infinity
• C. Constant✓
• D. Zero

Explanation: During the oscillations, the total energy is constant and equal to the sum of the potential energy and the kinetic energy of the system, ETotal=12kx2+12mv2=12kA2.Hence total energy of the particle performing SHM is conserved.

Q185. Maximum power delivered by battery is

• A. Pmax= E^2/4r✓
• B. Pmax = 4rE^2
• C. Pmax = VIT
• D. Unlimited

Explanation: It states that the output power of a source of current is maximum, when the internal resistance of the source is equal to the external resistance in the circuit. So, if R is the external resistance of the circuit and r is the internal resistance of the source of current (i.e. a battery) then the output power is maximum, when R = r. This theorem is applicable to all types of source of e.m.f. and is related with the output power and NOT with the power dissipated. If E is the applied e.m.f. of the source of e.m.f. i.e. a battery of internal resistance r and R is the external resistance then current in the circuit is given as: I = E/(R + r) At the maximum output power, R = r, so we have: I = E/(r + r) = E/(2r) and maximum output power: Pmax = I2r = E2/(4r)

Q186. A bus and a car, moving at the same speed, are brought to rest by applying the same retarding force then:

• A. Bus will come to rest in a shorter distance
• B. Car will come to rest in a shorter distance✓
• C. Both will come to rest in the same distance
• D. None of the above

Explanation: The distance they move will depend on their deceleration, which in turn would depend on the frictional force exerted by their respective brakes. If both were to experience the same frictional force 'F', then as per F=ma it is evident that the car having the lesser mass will decelerate faster ( greater magnitude of deceleration) and will therefore come to a halt sooner. Conceptually this is due to the effect of inertia as the bus has a greater mass of two vehicles.

Q187. Current carrying loop behaves like a

• A. Monopole
• B. Dipole✓
• C. Quadrupole
• D. Octupole

Explanation: The current carrying loop behaves like a dipole having two poles north and south.

Q188. The ionization power of _ ray is highest.

• A. Beta
• B. Gamma
• C. He-Ne laser
• D. None of these✓

Explanation: Among the three types of common radiation, alpha particles have the highest ionization power.Alpha particles are composed of two protons and two neutrons, and they have a positive charge. When they pass through matter, they interact strongly with the electrons and atoms of the material, causing a large number of ionizations. This means that they can knock off electrons from atoms, creating positively charged ions and free electrons, which can go on to create further ionizations.In comparison, beta and gamma radiation have lower ionization power.

Q189. Two wires of copper are of the same length but have different diameters. When they are connected in series across a battery, the heat generated is H1, when connected in parallel across the same battery, the heat generated during the same time is H2 Then :

• A. H1 = H2
• B. H1 < H2✓
• C. H1 > H2
• D. None of the above

Explanation: When two wires of the same material and length are connected in series, their total resistance increases, which leads to a decrease in the current flowing through the circuit according to Ohm's Law (V = IR). As a result, the heat generated (H) is given by the equation H = I2Rt. In parallel, the effective resistance decreases, allowing more current to flow and therefore more heat to be produced over the same time period. Thus, we conclude that H1 (heat generated in series) is less than H2 (heat generated in parallel), making option B the correct answer. Other options are incorrect as they do not accurately reflect the relationships between current, resistance, and heat generation in different circuit configurations.

Q190. A handball is tossed vertically upward with a velocity of 19.6 m/s. Approximately how high will it rise?

• A. 15.8 m
• B. 19.6 m✓
• C. 25.6 m
• D. 30 m
• E. 60 m

Explanation: Initial velocity = 19.6 m/s Equations of motion = v = u - gt Height h = ut - 1/2 * g * t^2 v = final velocity at max. height = 0 g = acceleration due to gravity = 9.8 m/s^2 t = time of motion Hence we have, 0 = 19.6 - 9.8t t = 2 s h = 19.6 * 2 - 1/2 * 9.8 * 4 = 19.6 m

Q191. The half-life of C14 is about:

• A. 1637 years
• B. 892 years
• C. 10 years
• D. 100 years
• E. 5730 years✓

Explanation: Carbon-14 has a half-life of 5,730 ± 40 years—i.e. half the amount of the radioisotope present at any given time will undergo spontaneous disintegration during the succeeding 5,730 years.

Q192. Angular displacement is zero when:

• A. angle =0✓
• B. v=0
• C. r=0
• D. both b and c

Explanation: Arc length (s) is found by the formula = radius x angular displacement so angular displacement = arc length / radius and it can only be zero when the angle is zero.

Q193. What should come next: save, secure, protect, -----

• A. Guard✓
• B. Lock
• C. Conserve
• D. Humble

Explanation: Save is a synonym of secure so to follow the pattern the answer needs to be a synonym of protect, which is guard. So, the correct option is A.

Q194. Complete the series. F16, H32, J48, _.

• A. K66
• B. L64✓
• C. M68
• D. N90

Explanation: 16 is added every time to each term and the letters alternate. So after J, K will be skipped and 48+16 is 64 so the answer is L64.

Q195. If '-' means'+', '+' means '-', '*' means '÷' and '÷' means '*' then which of the following will be the correct equation?

• A. 30 + 5 +14 -10 * 15 = 122
• B. 10 + 5 - 14 + 10 * 15 = 158
• C. 30 - 5 + 14 +10 * 15 = 162
• D. 30 * 5 - 4 + 10 - 30 = 30✓

Explanation: Option A: 30 + 5 +14 -10 * 15 = 122= 30 - 5 - 14 + 10 ÷ 15 (substituting the new symbols)= 30 - 5 - 14 + 0 (10 ÷ 15 = 0)= 11Option B: 10 + 5 - 14 + 10 * 15 = 158= 10 - 5 + 14 ÷ 10 - 15 (substituting the new symbols)= 10 - 5 + 1 - 15 (14 ÷ 10 = 1)= -9Option C: 30 - 5 + 14 +10 * 15 = 162= 30 + 5 - 14 - 10 ÷ 15 (substituting the new symbols)= 30 + 5 - 14 - 0 (10 ÷ 15 = 0)= 21 Option D: 30 * 5 - 4 + 10 - 30 = 30= 30 ÷ 5 + 4 - 10 + 30 (substituting the new symbols)= 6 + 4 - 10 + 30 (30 ÷ 5 = 6)= 30

Q196. Which one of the following has four sides:

• A. Triangle
• B. Square✓
• C. Circle
• D. Right triangle

Explanation: Correct option is B. Square has 4 sides.

Q197. Statement: Without reforming the entire administrative system, we cannot eradicate corruption and prejudice from society.Assumptions:I. The existence of corruption and prejudice is good.II. There is enough flexibility to change the administrative system.

• A. Only assumption I is implicit
• B. Only assumption II is implicit✓
• C. Either assumption I or II is implicit
• D. Both Options A and B are correct

Explanation: The statement talks of eradicating corruption and prejudice from society, which indicates that these aspects are undesirable. The existence of corruption and prejudice is not good as they create unfair opportunities for different groups. So, the assumption I is not implicit. Besides, the statement mentions reforming the administrative system. So, assumption II is implicit.

Q198. I. North Korea is protesting with South Korea for firing at their aircraft. II. South Korea Airforce is rightfully aiming for North Korean aircraft flying within the premises.

• A. Both statements I and II are the effects of independent causes.
• B. Statement II is the cause and statement I is its effect.✓
• C. Both statements I and II are independent causes.
• D. Statement I is the cause and statement II is its effect.

Explanation: The correct answer is that Statement II is the cause and Statement I is its effect. In the scenario described, South Korea's action of aiming at North Korean aircraft (Statement II) prompts a reaction from North Korea, which is to protest (Statement I). In other words, the protest is a response to the action of aiming. The other options are incorrect because they either suggest independence, which does not apply here, or reverse the cause-effect relationship.