Pk Mdcat Mock 3 — Solved Past Paper with Answers

Q1. Which part is incorrect in the following sentence? I found this bangle (A) while digging (B) in the backyard. (C) I don't know who it belonged to. (D)

• A. I found this bangle
• B. While digging
• C. In the backyard
• D. I don't know who it belonged to✓

Explanation: It should be ‘to whom it belonged’. The sentence should read: I don’t know to whom it belonged. When the relative pronoun is the object of the relative clause, we use whom instead of who. Note that, in this case, the preposition normally goes before whom.

Q2. Identify that underlined segment of the sentence, which contains the mistake that needs to be corrected. My brother doesn’t care how much does the car cost because he is going to buy it anyway.

• A. My brother
• B. Does the car cost✓
• C. Because
• D. He is going to buy

Explanation: The key to solving these questions is to read the sentence in your head and decide which segment does not fit in well. Over here the word ‘does’ is redundant and the sentence would be better phrased if it was: ‘how much the car costs because…’

Q3. In the following question, four alternative sentences are given. Choose the CORRECT one.

• A. In my experience, the awakening of that clear judgemeent as to what the college is for, is not as difficult as is often supposed.
• B. In my experience, the awakening of a clear judgement as for what the college is for,is not as difficult as is often supposed.
• C. In my experience, the awakening of a clear judgement as to what the college is for, is not as difficult as is often supposed.✓
• D. In my experience, the awakening of a clear judgement as to what the college is for, is not as much as difficult as often supposed.

Explanation: The best way to solve this question is to read each option in your head and then decide which one sounds the best and fits in well. In Option A, the spelling of judgement is incorrect. In Option B, there is no space left after the comma which is the wrong punctuation. In Option D, as much as is unnecessary text and can be removed.

Q4. Choose the word most similar In meaning to the capitalized one: INEVITABLE:

• A. Doubtful
• B. Deny
• C. Unexpected
• D. Certain✓
• E. Unusual

Explanation: Inevitable means something which is bound to happen or is very certain, undoubtful, and clear.

Q5. Demonstrate correct use of subject-verb agreement Ninety rupees _ too much for this bag.

• A. Is✓
• B. Are
• C. Be
• D. Were

Explanation: The subject in this question is the singular noun “bag”, hence “is” will be used.

Q6. Choose the correct sentence:

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

Explanation: Option A: This sentence is missing a comma before "and." It should be "an orange, and a pear." The absence of the comma makes the sentence grammatically incorrect.Option B: This sentence is also missing a comma before "and." Similar to option A, it should be "an orange, and a pear." The lack of a comma makes this sentence grammatically incorrect as well.Option C: This sentence is correctly punctuated with commas. It uses the comma before "and" when listing three items. Each item in the list is separated by a comma, and the final comma (known as the Oxford comma) is used before "and." This option is grammatically correct.Option D: Similar to options A and B, this sentence is missing a comma before "and." It should be "an orange, and a pear." The absence of a comma makes this sentence grammatically incorrect.

Q7. 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".

Q8. Pick the correct option:

• A. Seven students results are still awaited.
• B. Seven student’s results are still awaited.
• C. Seven students’ results are still awaited.✓
• D. Seven student results are still awaited.

Explanation: Plural nouns that end with 's' only, follow this rule;For example: The two cats' nails have grown long. On other hand:The thieves snatched the two women's bags.

Q9. Identify the word or phrase that needs to be changed for the sentence to be correct. This long experience of European domination has naturally produced a mood of quite resistance.

• A. This
• B. Long
• C. European
• D. Quite✓

Explanation: Over here quite is wrongly used as the other homophone (quiet) was the intended word. Meaning the resistance is very quietly developing in secret. Quite is an adverb used to describe when something is a little or a lot but not completely. Quiet is an adjective used to describe something or someone that makes very little noise.

Q10. Demonstrate control of tenses and sentence structure: When I go swimming, I have to keep my eyes closed underwater.

• A. Complex✓
• B. Simple
• C. Compound
• D. None of these options are correct

Explanation: A complex sentence is a sentence with one independent clause and at least one dependent clause.

Q11. Demonstrate correct use of articles and prepositions. Demonstrate correct use of the subject-verb agreement. Demonstrate correct use of writing conventions of spelling, capitalization and punctuation to clarify meaning. Had you worked hard (A)/ from the beginning (B)/ of the term (C)/ you will have passed. (D)

• A. Had you worked hard
• B. from the beginning
• C. of the term
• D. you will have passed✓

Explanation: In statement D, the word 'would' should replace 'will' as the future is being talked about in regards to a past event.

Q12. The two machines _ considerably. One has an electric motor, and the other one runs on oil.

• A. Different
• B. Differentiate
• C. Differ✓
• D. Difference

Explanation: As verbs, the difference between differ and differs is that differ is not to have the same traits, characteristics, while differs, is (differ).

Q13. Choose the correct answer:

• A. A friend of him told us the sad news of his father’s demise.
• B. Friend of him told us the sad news of his father’s demise.
• C. A friend of his told us the sad news of his father’s demise.✓
• D. A friend of him told the sad news of his father’s demise.

Explanation: -Option A, B & D use the wrong pronoun. Correct pronoun is: A friend of his instead of A friend of him. -Option B does not use article “A” at the start of the sentence. -Option D misses the word “us” (told us) Hence, option C is correct.

Q14. Read the passage. Then answer the questions below.Mona doesn’t like to ask people for help. But it is hard for her to perform daily activities on her own. She is almost 13, yet she is no larger than a 5-year-old. Mona has trouble keeping her balance and can’t walk very far. When she uses a wheelchair, she can’t push it herself. Fortunately, Mona has a wonderful service dog named Sam. A service dog is a dog that has been trained to assist someone who has a physical problem. Sam lets Mona lean on him when she walks. He also pulls her wheelchair and turns lights on and off. When Mona drops something, Sam picks it up. He even pulls her socks off at night.Sam also helps Mona with everyday tasks at school. He carries her books from class to class in a special backpack. He puts Mona’s completed assignments in her teachers’ homework trays. In the lunchroom he throws away her trash.Besides making Mona less dependent on other people, Sam helps her lead a fuller life.Mona’s classmates flock around Sam like geese. This has helped her make friends. Sam also helps Mona be more active. With his aid, she raised over $500 in a walk-a-thon for her local humane society.Because of Sam, Mona doesn’t have to ask people for help. Sam brings her closer to other kids. And he even helps her contribute to her community. Using the passage as a guide, which of the following dogs is most likely a service dog?

• A. Frank's dog, who turns on the lights when Frank enters the room.✓
• B. Raul's dog, who fetches the newspaper for Raul while he is busy getting dressed
• C. Mei's dog, who licks Mei’s face when she cries.
• D. Teddy's dog, who loves to play catch, go on walks, and watch movies with the family.

Explanation: In paragraph 2, the author tells us a service dog is “a dog that has been trained to assist someone who has a physical problem.” Later in the paragraph, the author tells us that Mona's service dog "pulls her wheelchair and turns lights on and off." This lets us know that a service dog does things that help someone who has a physical problem. Since Frank's dog turns on the lights when Frank enters the room, we can understand that this is something that a dog would do to help someone who has a physical problem. Therefore, it is most likely that Frank's dog is a service dog. This means choice (A) is correct. Raul's dog helps Raul by fetching the newspaper while he gets dressed. Although this is helpful, there is no indication that Raul is disabled, or that he needs a dog to do this work for him. This eliminates choice (B). Although it seems sweet that Mei's dog licks Mei’s face when she cries, this is not an act of helping her do something that she cannot do on her own. This means (C) is incorrect. (D) is incorrect because Teddy's dog does not do anything beyond what an ordinary dog would do.

Q15. Read the passage and answer the question given at the end of the passage: Recent advances in science and technology have made it possible for geneticists to find out abnormalities in the unborn fetus and take remedial action to rectify some defects which would otherwise prove to be fatal to the child. Though genetic engineering is still at its infancy, scientists can now predict with greater accuracy a genetic disorder. It is not yet an exact science since they are not in a position to predict when exactly a genetic disorder will set in. While they have not yet been able to change the genetic order of the gene in germs, they are optimistic and are holding out that in the near future they might be successful in achieving this feat. However, genetic misinformation can sometimes be damaging for it may adversely affect people psychologically. Genetic information may lead to a tendency to brand some people as inferiors. Genetic information can therefore be abused and its application in deciding the sex of the fetus and its subsequent abortion is now hotly debated on ethical lines. But on this issue geneticists cannot be squarely blamed though this charge has often been levelled at them. It is mainly a societal problem. At present genetic engineering is a costly process of detecting disorders but scientists hope to reduce the costs when technology becomes more advanced. This is why much progress in this area is seen in scientifically advanced and rich countries like the U.S.A, UK, and Japan. It remains to be seen if in the future this science will lead to the development of a race of supermen or will be able to obliterate disease from this world. Which of the following is true regarding the reasons for progress in genetic engineering?

• A. It has become popular to abort female fetuses
• B. Human beings are extremely interested in heredity
• C. Economically sound and scientifically advanced countries can provide the infrastructure for such research✓
• D. Poor countries desperately need genetic information.

Explanation: From the passage: ‘......At present genetic engineering is a costly process of detecting disorders but scientists hope to reduce the costs when technology becomes more advanced. This is why much progress in this area is seen in scientifically advanced and rich countries like the U.S.A….’

Q16. Read the passage. Then answer the questions below. Many people like to eat pizza, but not everyone knows how to make it. Making the perfect pizza can be complicated, but there are lots of ways for you to make a more basic version at home. When you make pizza, you must begin with the crust. The crust can be hard to make. If you want to make the crust yourself, you will have to make dough using flour, water, and yeast. You will have to knead the dough with your hands. If you do not have enough time to do this, you can use a prepared crust that you buy from the store. After you have chosen your crust, you must then add the sauce. Making your own sauce from scratch can take a long time. You have to buy tomatoes, peel them, and then cook them with spices. If this sounds like too much work, you can also purchase jarred sauce from the store. Many jarred sauces taste almost as good as the kind you make at home. Now that you have your crust and your sauce, you need to add the cheese. Cheese comes from milk, which comes from cows. Do you have a cow in your backyard? Do you know how to milk the cow? Do you know how to turn that milk into cheese? If not, you might want to buy cheese from the grocery store instead of making it yourself. When you have the crust, sauce, and cheese ready, you can add other toppings. Some people like to put meat on their pizza, while other people like to add vegetables. Some people even like to add pineapple! The best part of making a pizza at home is that you can customize it by adding your own favorite ingredients. In paragraph 4, the author asks a series of questions in order to

• A. Support the idea that most people cannot make homemade cheese✓
• B. Reinforce the idea that most people probably live on farms
• C. Prove that store-bought cheese tastes better than homemade chees
• D. Emphasize the superiority of homemade cheese over store bought cheese

Explanation: In paragraph 4, the author asks the reader, "Do you have a cow in your backyard? Do you know how to milk the cow? Do you know how to turn that milk into cheese?" The author thinks that he or she knows the answer to these questions. The author thinks that you probably do not have a cow in your backyard, do not know how to milk a cow, and do not know how to turn milk in cheese. After all, not many people would answer these questions positively. Given that the author expects that most people would not answer positively to these questions, then it is fair to assume that most people are unable to make home-made cheese. The author’s question is intended to be rhetorical, or perhaps even sarcastic. This means choice (A) is correct. The passage does not provide information to support choices (B), (C), and (D). Therefore they are incorrect.

Q17. In the following question, four alternative meanings of a word are given. Select the nearest correct meaning of the word given. FURTIVE:

• A. Furious
• B. Familiar
• C. Secretive✓
• D. Easy

Explanation: Furtive means “attempting to avoid notice or attention, typically because of guilt or a belief that discovery would lead to trouble; secretive.”

Q18. When the hydroxyl group, -OH, of the carboxyl group, -COOH, of an amino acid is linked with the hydrogen of the amino group, -NH2, of another amino acid, _ is released and a peptide bond is formed.

• A. NH3
• B. CO2
• C. H2O✓
• D. O2

Explanation: Peptide bond formation is a condensation process which involves removal of water molecule

Q19. In which of the following phases of bacterial growth, is the death rate more rapid than the multiplication rate?

• A. Stationary phase
• B. LAG phase
• C. Decline phase✓
• D. LOG phase

Explanation: This is the following solution:

Q20. Bacteria having a tuft of flagella at one end are called:

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

Explanation: There are four types of flagellar arrangements based on the number and placement of flagella on the cell. These are, 1. Monotrichous - A single flagellum extends from one end of the cell. 2. Amphitrichous - A single flagellum or multiple flagella extend from two ends of the cell. 3. Lophotrichous - Tuft of flagella extend from one end of the cell. 4. Peritrichous – Multiple flagella randomly distributed over the entire bacterial cell. Thus, the correct answer is 'Lophotrichous.' Option A, B and D are incorrect as their description does not match the requirement of the question i.e. bacteria having a tuft of flagella at one end of the cell.

Q21. Germ theory was presented by:

• A. Robert Koch✓
• B. Antonie van Leeuwenhoek
• C. Robert Hooke
• D. Robert Brown

Explanation: Proposing the germ theory of disease was the crowning achievement of the French scientist Robert Koch. Robert Hooke discovered the Law of Elasticity (or Hooke's Law) and did a huge amount of work on cell theory. Robert Brown used a microscope to describe the nucleus of a cell. He also developed the idea of what is now called the Brownian motion which explained the random movement of minute particles in a fluid.

Q22. Sliding filament theory can be best explained as

• A. actin and myosin filaments do not shorten but rather slide pass each other✓
• B. when myofilaments slide pass each other, myosin filaments shorten while actin filaments do not shorten
• C. when myofilaments slide pass each other actin filaments shorten while myosin filaments do not shorten
• D. actin and myosin filaments shorten and slide pass each other.

Explanation: During muscle contraction, the laterally projecting heads (cross bridges) of the thick myosin myofilaments come in contact with the thin actin myofilaments and rotate on them. This pulls the thin myofilaments toward the middle of the sarcomere, past the thick myofilaments. The Z lines come closer together and the sarcomere becomes shorter. Length of the A band remains constant. Myofilaments (both actin and myosin) stay the same length. Free ends of actin myofilaments move closer to the centre of the sarcomere, bringing Z lines closer together. I bands shorten and H zone narrows. A similar action in all the sarcomeres results in shortening of the entire myofibril and thereby of the whole fibre and the whole muscle.

Q23. NADH produces how many ATP?

• A. 2 ATP
• B. 3 ATP✓
• C. 4 ATP
• D. 6 ATP

Explanation: NADH can produce 3 ATP molecules. FADH can produce 2 ATP molecules.

Q24. Erythroblastosis foetalis occurs when:

• A. Mother is Rh-positive and Baby is Rh-negative
• B. Mother is Rh-negative and the Baby is Rh-positive✓
• C. Both Mother and Baby are Rh-negative
• D. Both Mother and Baby are Rh-positive
• E. All of the above statements are true

Explanation: When an Rh-negative mother has an Rh-positive child, erythroblastosis fetalis occurs. This can be understood by the fact that the Rh-negative mothers can’t recognize Rh antigen so the mixing of the blood during delivery causing an immune response against the fetus’ antigen.

Q25. Example of bacteria requiring low concentration of oxygen is?

• A. Spirochete
• B. Seudomonas
• C. E.coli
• D. Campylobacter✓

Explanation: Campylobacter is a genus of bacteria that are mostly microaerophilic, i.e. they require a very low concentration of oxygen to survive. At higher concentrations, these can not survive.

Q26. Magnesium is important for the synthesis of which of the following?

• A. Chlorophyll✓
• B. Protein synthesis
• C. Glucose metabolism
• D. All of these

Explanation: Magnesium ions help in the manufacturing of the chlorophyll pigment.

Q27. The diagram shows an apparatus set up to investigate the effect of changing the concentration of glucose in the surrounding solution on the movement of molecules through a selectively permeable membrane (Visking tubing) in 15 minutes. As the concentration of glucose solution in the surrounding solution increases, which of the following statements are correct? Net diffusion of water increases. Glucose molecules reach an equilibrium quicker. There is less change in the volume of the surrounding solution. Net diffusion of glucose increases.

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

Explanation: As the concentration of glucose of the surrounding solution increases, the equilibrium concentration of glucose is reached faster and there is less change in the volume of the surrounding solution: statements II and III are correct.Net diffusion of water however decreases because the difference in concentration of glucose between two solutions decreases(I is wrong). Glucose is not permeable through a selectively permeable membrane or even if it is with a decrease in gradient its net diffusion will decrease.

Q28. Which of the following is an unsaturated fatty acid?

• A. Oleic acid✓
• B. Palmitic acid
• C. Butyric acid
• D. Acetic acid

Explanation: Unsaturated fatty acids have one or more carbon-carbon double bonds. The term unsaturated indicates that fewer than the maximum possible number of hydrogen atoms are bonded to each carbon in the molecule. Oleic acid is an example of a monounsaturated fatty acid as it has only a single double bond present in the long chain of carbons bonded to each other.Butyric acid (butanoic acid) is a 4-carbon saturated carboxylic acid. Acetic acid (ethanoic acid) is a carbon-2 saturated carboxylic acid. Palmitic acid is a 16-carbon saturated carboxylic acid.

Q29. The oxygen and carbon dioxide crosses the plasma membrane by the process of:

• A. Active diffusion
• B. Facilitated diffusion
• C. Passive diffusion✓
• D. Random diffusion

Explanation: Passive diffusion, also known as simple diffusion, is a process by which molecules move across a membrane from an area of higher concentration to an area of lower concentration. This process is responsible for the movement of oxygen and carbon dioxide across the Plasma membrane.

Q30. How many carbons does citrate have in the Krebs cycle?

• A. 5
• B. 6✓
• C. 8
• D. 4

Explanation: In the first step of the cycle, acetyl CoA combines with a four-carbon acceptor molecule, oxaloacetate, to form a six-carbon molecule called citrate.

Q31. What would be the magnification of the objective length in a microscope if the eyepiece is 10X and the total magnification is 40X?

• A. 4✓
• B. 10
• C. 40
• D. 400

Explanation: The total magnification is equal to the magnification of the eyepiece multiplied by the magnification of the objective lens. So in this case, the total magnification divided by eyepieces is 40 divided by 10 which gives us 4.

Q32. The family tree shows the inheritance of the ability to taste a certain substance. The allele for the ability to taste this substance is dominant to the allele for the inability to taste it. What percentage of children of Pasha and Hina would be ‘non - tasters’?

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

Explanation: Pasha is a “taster” and he is heterozygous for being a taster. Heterozygous, because Pasha’s father was a non-taster that must have given an allele for being non-taster allele, which is recessive.When a heterozygous is crossed with a homozygous recessive allele. There are 50:50 chances of phenotype being taster:non-taster.

Q33. What is the risk of color blind baby boy in a family when mother is color blind but father is normal?

• A. 25%
• B. 50%
• C. 75%
• D. 100%✓

Explanation: The gene for color blindness is located on the X chromosome and the offspring receives it from the mother. Father gives Y chromosomes to his son and X to daughter.Now the son gets the defective gene from the mother but there is no allele of color blindness in the Y chromosome, so the disease will show, and in this way, all the sons will be color blind.

Q34. The Induced fit model was introduced by Koshland in which of the following year?

• A. 1960
• B. 1961
• C. 1959✓
• D. 1966

Explanation: The induced-fit model was first proposed by Koshland in 1959 to explain the protein conformational changes in the binding process. This model suggests that an enzyme when binding with its substrate optimizes the interface through physical interactions to form the final complex structure.

Q35. Match the parts of the human brain listed under Column I with the functions given under Column II. Choose the answer which gives the correct combination of alphabets of the two columns.

• A. A=r, B=q, C=p, D=s
• B. A=r, B s, C=q, D=t,
• C. A=t, B=p, C=q, D=r✓
• D. A=t, B=q, C=p, D=s

Explanation: Your cerebral hemisphere plays a key role in memory, intelligence, thinking, learning, reasoning, problem-solving, emotions, consciousness, and functions related to your senses. (so A=T, hence options A and B are incorrect). The thalamus is your body's information relay station. All information from your body's senses (except smell) must be processed through your thalamus before being sent to your brain's cerebral cortex for interpretation (so B=P, hence options A, B, and D are incorrect). The cerebellum controls voluntary movements such as walking, posture, balance, coordination, eye movements, and speech (C=Q). Neurons in the medulla also control arousal and sleep (D=R).

Q36. The light dependent reaction of photosynthesis occurs in:

• A. Stroma of chloroplast
• B. Guard cells of stomata
• C. Thylakoid membrane of chloroplast✓
• D. Cytoplasm of leaf cell

Explanation: The light-dependent reactions use light energy to make two molecules needed for the next stage of photosynthesis: the energy storage molecule ATP and the reduced electron carrier NADPH. In plants, the light reactions take place in the thylakoid membranes of organelles called chloroplasts.

Q37. Who discovered the bacteria causing tuberculosis and also developed various techniques of media preparation and maintenance of pure culture?

• A. Robert Koch✓
• B. Louis Pasteur
• C. Alexander Fleming
• D. Antonie van Leeuwenhoek

Explanation: Fact.

Q38. Which of the following statements about the head of a chlorophyll molecule is incorrect?

• A. It is a porphyrin ring or tetrapyrrole ring structure
• B. It is flat, square and light absorbing
• C. Composed of carbon and nitrogen atoms with magnesium as central metal ion.
• D. It is hydrophobic✓

Explanation: Chlorophyll molecules have a complex structure consisting of the hydrophobic tail region and hydrophilic head region because it needs to interact with the surrounding aqueous environment. Now this is the wrong option and the question did ask for an incorrect one, hence option d is right as it fulfills the criteria of the question.

Q39. The scrotum is responsible for·which of the following in the male reproductive system?

• A. Synthesis of sperm
• B. Lubrication
• C. Nourishment of sperm
• D. Temperature regulation✓

Explanation: The 'temperature' is controlled by the scrotal movement of the testes away or toward the body depending on the environmental temperatures. Moving the testes away from the abdomen and increasing the exposed surface area allows a faster dispersion of excess heat.

Q40. Hybrid black Guinea pigs are crossed with each other. The resulting offsprings will be:

• A. All black
• B. All white
• C. 3 black, 1 white✓
• D. 3 white, 1 black

Explanation: When heterozygous (hybrid) guinea pigs are intercrossed the chance of the offspring being black is: 75 % and white is: 25%, giving 3 blacks and 1 white (Option C)

Q41. Average loss of blood during birth is about how many cm3?

• A. 250
• B. 300
• C. 350✓
• D. 400

Explanation: Within 10-45 minutes after birth, the uterus contracts and separate the placenta from the wall of the uterus and placenta then passes out through the vagina. This is called after birth. Bleeding, throughout this period, is controlled by the contraction of smooth muscle fibers which completely surround all uterine blood vessels supplying the placenta. Average loss of blood is about 350 cm3.

Q42. In a bacterial cell, plasma membrane with all things present within it is called:

• A. Cytoplasmic matrix
• B. Cytoplasm
• C. Protoplast✓
• D. Cell Structure

Explanation: The protoplasm consists of two major divisions in eukaryotes: the cytoplasm, and the nucleoplasm (cell nucleus). The cytoplasm is the eukaryotic cell's jelly-like material. Except for the nucleus it consists of the cytosol, the vesicles, the cytoskeleton, the inclusions and the organelles.

Q43. Which of the following are present in the internal organs like stomach, intestine, etc.?

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

Explanation: The stomach and the intestine have inner layers of smooth muscles. The characteristic properties of smooth muscles are that they are not striated, nor multi nucleated and they have tapering ends. The description matches A so the answer is A.

Q44. Which one of the following are “myogenic” type of muscles?

• A. Glandular muscles
• B. Cardiac muscles✓
• C. Skeletal muscles
• D. Smooth muscles

Explanation: The three muscle types (Cardiac, Smooth, Skeletal) can be further classified into two categories i.e. myogenic and neurogenic. Myogenic means originating in or produced by muscle cells themselves. Neurogenic means originating in or produced by nerve cells or neurons. The contractions of cardiac muscle fibers are described as myogenic, since they are produced spontaneously, without requiring stimulation from nerve cells. This is solely due to the presence of the SA and AV nodes on the heart, capable of producing electrical impulses to stimulate contraction. Single-unit visceral smooth muscle is myogenic; it can contract regularly without input from a motor neuron (as opposed to multiunit smooth muscle, which is neurogenic - that is, its contraction must be initiated by an autonomic nervous system neuron). Skeletal muscle on the contrary is neurogenic since it can contract when stimulated by a motor neuron. Hence, the only correct answer is Option B.

Q45. Many substances which are urgently required by the cell while cell absorbs them against the concentration gradient by utilizing energy in the form of:

• A. ATP✓
• B. Heat
• C. GTP
• D. Light

Explanation: To move a substance against its concentration gradient, the cell utilises energy in the form of ATP which is an energy carrier

Q46. DNA is found in which of the following structures?

• A. Golgi complex
• B. Lysosomes
• C. Mitochondria✓
• D. Ribosomes

Explanation: DNA can be found in the mitochondria as they are thought to be primitive bacteria that have infiltrated into the cell.

Q47. Red green colour blindness is a sex linked recessive trait. If a colour blind man marries a woman with normal vision whose father is colourblind and they have a daughter, what is the probability that she will be colourblind?

• A. 0
• B. 0.25
• C. 0.50✓
• D. 0.75

Explanation: Male has colorblind-vision so his genotype will XcYFemale has a normal vision but had a father with colorblind vision that means she is heterozygous,so her genotype will be XcX.XcX and XcY will give:XcXc,XcY,XcX and XY.There four equal possibilities of having children,out of which two are females and two are males. Out of two females,there is a 50:50 chance of having a one normal and one colourblind female as a daughter,hence the answer to this question is C.

Q48. Synaptic vesicles discharge which hormone at the neuromuscular junction?

• A. Acetylcholine✓
• B. Adrenaline
• C. Estradiol
• D. Testosterone

Explanation: Acetylcholine is the hormone discharged at the neuromuscular junction. The neuromuscular junction is a specialized synapse between a motor neuron and a muscle fiber. When an action potential reaches the nerve terminal (end of the motor neuron), it triggers the release of a neurotransmitter called acetylcholine from synaptic vesicles. Acetylcholine diffuses across the synaptic cleft and binds to receptors on the muscle cell membrane. This binding causes a series of events that ultimately lead to muscle contraction.

Q49. Transport of three protons through the ATPase complex is required for the production of one _.

• A. Sugar molecule
• B. NADP molecule
• C. ATP molecule.✓
• D. NADPH' molecule

Explanation: The H+/ATP ratio, defined as the number of protons necessary to synthesize one ATP at equilibrium, is three. Three protons H+ move through the ATPase complex to generate energy that is used to condensing ADP + Pi to form ATP.

Q50. The bacterial envelope does not include:

• A. Cell wall
• B. Slime
• C. Capsule
• D. Cell membrane✓

Explanation: Cell envelope includes capsule, slime and cell wall. The bacterial envelope contains a cell wall made up of peptidoglycans and a bilayer cell membrane (double). Capsule is present outside the cell envelope and slime is a part of the capsule.

Q51. Which of the following X - linked recessive trait that is more common in human males than in human females?

• A. Hemophilia✓
• B. Sickle cell Anemia
• C. Color Blindness
• D. Hypophosphatemic rickets
• E. Testicular feminization syndrome

Explanation: Haemophilia is a X-linked recessive disorder. Being a recessive disorder, it is expressed only in homozygous recessive conditions. Human males have one copy of X-chromosome and hence one copy of the affected gene in males in each cell is sufficient to cause the disorder (XhY). Hence, being X-linked recessive mutation, it is more frequent in males. Females carry two X-chromosomes and this females with two copies of the affected gene show the disorder (XhXh ). Females heterozygous (XHXh) for this trait be normal but serve as a carrier of the disease. Red-green colour blindness is also X-linked recessive but the question does not specify the type of colour blindness.

Q52. When a color-blind male marries a normal female, what will be the chances of colorblindness in his grandsons, if his daughter. married to a normal male?

• A. 16%
• B. 25%✓
• C. 50%
• D. 100%

Explanation: Color Blindness is an X-linked recessive disorder. A man requires only one copy of defective genes to be colourblind. Whereas a woman requires two copies of defective genes to be colourblind. When a colourblind (XcY) man marries a normal woman (XX), all of their sons will be normal (XY) and all of their daughters will be carriers (XcX). Hence, in the next generation, all the children of all of their sons will be normal. There will be a nil probability of being colourblind. In the next generation of their daughter, all the daughters will be either normal or carrier. Whereas 50% of the sons will be colourblind acquiring defective genes (Xc) from their mother. Hence, considering the grandsons of daughter, there are 25% chances or 0.5 probability of the grandson being colourblind.Thus, the correct answer is option B

Q53. Repolarization is restored when:

• A. Sodium ions diffuse in
• B. Potassium diffuses out✓
• C. Potassium diffuses in
• D. Sodium diffuses out

Explanation: Repolarization is restored when potassium ions diffuse out of the neuron. This is because potassium ions are more concentrated inside the neuron than outside the neuron. When the neuron fires an action potential, sodium ions rush into the neuron, making the inside of the cell more positive. This causes the potassium ions to diffuse out of the cell, restoring the resting membrane potential.

Q54. A major constituent of contraceptive pills is:

• A. Estrogen
• B. Progesterone✓
• C. Prolactin
• D. Testosterone

Explanation: The most commonly prescribed contraceptive pill is the combined hormonal pill with progesterone. Progesterone is primarily responsible for preventing pregnancy. The main mechanism of action is the prevention of ovulation; they inhibit follicular development and prevent ovulation. Progestogen-negative feedback works at the hypothalamus to decrease the pulse frequency of the gonadotropin-releasing hormone. This, in turn, will reduce the secretion of follicle-stimulating hormone (FSH) and decrease the secretion of luteinizing hormone (LH). If the follicle isn’t developing, there is no increase in the estradiol levels (the follicle makes estradiol). The progestogen-negative feedback and lack of estrogen-positive feedback on LH secretion stop the mid-cycle LH surge. With no follicle developed and no LH surge to release the follicle, ovulation is prevented.

Q55. Gradual breakdown of the alveolar wall leads to which type of disease in a smoker?

• A. Coronary heart disease
• B. Bronchitis
• C. Emphysema✓
• D. Asthma

Explanation: In emphysema, the inner walls of the lungs' air sacs (alveoli) are damaged, causing them to eventually rupture. This creates one larger air space instead of many small ones and reduces the surface area available for gas exchange. Emphysema is a lung condition that causes shortness of breath.Asthma is a condition in which your airways narrow and swell and may produce extra mucus. This can make breathing difficult and trigger coughing, a whistling sound (wheezing) when you breathe out and shortness of breath.Bronchitis is an infection of the main airways of the lungs (bronchi), causing them to become irritated and inflamed. The main symptom is a cough, which may bring up yellow-grey mucus (phlegm)Coronary heart disease (CHD), or coronary artery disease, develops when the coronary arteries become too narrow. The coronary arteries are the blood vessels that supply oxygen and blood to the heart.CHD tends to develop when cholesterol builds up on the artery walls, creating plaques. These plaques cause the arteries to narrow, reducing blood flow to the heart. A clot can sometimes obstruct the blood flow, causing serious health problems.

Q56. The pH at which the activity of pancreatic lipase enzyme is maximum is:

• A. 8.00
• B. 9.00✓
• C. 7.40
• D. 9.20

Explanation: The optimal pH for pancreatic lipase activity is 9.00. Pancreatic lipase is an enzyme that breaks down triglycerides into fatty acids and glycerol. It is secreted by the pancreas into the small intestine, where it functions in the digestion of dietary fats.

Q57. It serves as a base of attachment for the cytoskeleton in some organisms:

• A. Lysosomes
• B. Ribosomes
• C. Endoplasmic reticulum
• D. Plasma membrane✓

Explanation: The major cytoskeletal elements (microfilaments, microtubules, and 10-nm filaments) are frequently found attached to or near the plasma membrane in arrays which can sometimes be shown experimentally to be related to cell form and movement.

Q58. Which of the following neurotransmitters function, both as neurotransmitter and hormones, decreasing our perception of pain?

• A. Epinephrine
• B. Serotonin
• C. Dopamine
• D. Endorphins✓

Explanation: Neurotransmitters are chemical messengers that transmit a message from a nerve cell across the synapse to a target cell. Hormones are chemical messengers that are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions. All the options are both, a hormone as well neurotransmitters. Epinephrine, commonly referred to as Adrenaline, relaxes the airway muscles, making it easier for the person to breathe. At the same time, it constricts blood vessels, helping to improve blood pressure. It also increases the heart rate. However, it does not decrease the response to pain. Hence Option A is rejected. Serotonin, on the other hand, is used by the body to send messages between nerve cells. It appears to play a role in mood, emotions, appetite, and digestion. As the precursor for melatonin, it helps regulate sleep-wake cycles and the body clock. Since it is not used to decrease pain response, Option B is rejected. Dopamine is a neurotransmitter that plays a role in how we feel pleasure. It's a big part of our unique human ability to think and plan. However, it plays no role in the pain response. Hence Option C is rejected. Endorphins are substances produced by the nervous system to cope with pain or stress. They are often called “feel-good” chemicals because they can act as pain relievers and happiness boosters. Hence, Option D is correct.

Q59. Which vertebrae together are called pelvic vertebrae?

• A. Coccygeal and lumbar
• B. Sacral and lumbar
• C. Sacral and coccygeal✓
• D. Sacral and thoracic

Explanation: The single sacrum is formed by the fusion of five sacral vertebrae. Similarly, the coccyx or tailbone, results from the fusion of four small coccygeal vertebrae. The pelvic skeleton is formed in the area of the back, by the sacrum and the coccyx, and anteriorly and to the left and right sides, by a pair of hip bones. The two hip bones connect the spine with the lower limbs.

Q60. Match the hormones listed under column I with their functions listed under the column. Choose the answer which gives the correct combination of the alphabets of the II columns.

• A. A = s, B = r, C = p, D = q✓
• B. A = t, B = p, C = s, D = r
• C. A = s, B = q, C = r, D = t
• D. A = t, B = r, C = p, D = s

Explanation: One of the functions of oxytocin is to stimulate uterine contractions in labor and childbirth, so the correct letter is S for A (A=S), so options B and D are incorrect. Prolactin causes the breasts to grow and make milk during pregnancy and after birth, so the correct letter is R for B (B=R), so option C is also incorrect. LH triggers the release of an egg from the ovary i.e. ovulation. Progesterone helps to prepare the body for pregnancy by stimulating glandular development and the development of new blood vessels. This provides a good environment for implantation by a fertilized egg, so it aids in implantation. So option A is correct.

Q61. Which enzyme is administered to the patients of Severe Combined Immunodeficiency Disease (SCID)?

• A. Adenosine Deaminase (ADA)✓
• B. Pancreatic Enzyme
• C. ß-galactosidase
• D. ß-lactamase

Explanation: 'SCID' is due to Adenosine Deaminase (ADA) deficiency so, it is administered to overcome the deficiency. Hence, option A is correct. Pancreatic enzymes (B) partake in digestion. Beta-galactosidase (C) breaks down lactose into glucose and galactose in certain organisms. Beta-lactamase (D) is an enzyme produced by bacteria, that confers their resistance against beta-lactam drugs, such as penicillin, as it breaks down the beta-lactam ring present in these drugs.

Q62. Choose a correct statement among following:

• A. Spinal reflexes has 4 elements
• B. Lower motor neurons has cell body in anterior column of grey matter.✓
• C. Grey matter that lies transversely is lateral commissure
• D. Spinal cord has 3 equal parts

Explanation: B is the correct option as the cell bodies of the lower neurons are located in the ventral horn of the spinal cord gray matter and in the motor nuclei of the cranial nerves in the brainstem.A is incorrect as spinal reflexes has 3 elements. C is incorrect as the area of grey matter that lies transversely is the transverse commissure. D is incorrect as spinal cord is divided into 4 equal parts.

Q63. Enzymes for light-dependent reactions of photosynthesis would most likely be associated with?

• A. Outer membrane of the chloroplast
• B. Inner membrane of the chloroplast
• C. Stroma of the chloroplast
• D. Thylakoid membranes of the chloroplast✓

Explanation: The light-dependent reactions of photosynthesis occur in the thylakoid, with the photosystems being located in the thylakoid membrane.

Q64. Which of the following has a vital role in autophagy?

• A. Glyoxysomes
• B. None of these
• C. Golgi apparatus
• D. Lysosomes✓

Explanation: Autophagy is the self-digestion of damaged organelles in a cell. Lysosomes, also known as ''suicide sacs'', have lytic enzymes in them which when released cause the destruction of unwanted or damaged components in the cell. The glyoxysome is a plant peroxisome, especially found in germinating seeds, involved in the breakdown and conversion of fatty acids to carbohydrates for the nutrition of the seed. The Golgi apparatus works in the packaging from the ER that are further processed and sorted for transport to their eventual destinations(inside the cell, in the membrane, or transported outside).

Q65. A cross between F1 hybrids and either of parents is called:

• A. Back cross✓
• B. Test cross
• C. Reverse cross
• D. None of the above

Explanation: (A: Backcrossing) is a crossing of a hybrid with one of its parents. There is no "reverse cross" in genetics. A test cross is a type of back cross used to determine whether an individual expressing a dominant phenotype is homozygous or heterozygous. The question does not mention what the cross is being used for, therefore A is the most suitable choice.

Q66. In the sliding filament theory of muscle contraction, which option correctly describes function of ATP?

• A. ATP does all of these things during muscle contraction
• B. It allows the myosin head to detach from the actin filament✓
• C. It moves tropomyosin off of actin binding sites
• D. both A and B

Explanation: What is the role of ATP in sliding filament theory?Energy from ATP is required for the myosin head to release from the actin filament—otherwise the myosin heads would remain in the same place, and the muscle would not contract. Even though the filaments are moving, the filaments themselves never actually get shorter or longer.Sliding filament theory:• During muscle contraction, thin filaments show sliding inward towards the H-zone.• Sarcomere shortens, without changing the length of thin and thick myofilaments.• The cross bridge of the thick myofilaments connects with the portions of actin of the thin myofilaments. These cross bridge move on the surface of the thin myofilaments resulting to sliding of thin and thick myofilaments over each other.• A muscle fibre maintains a resting potential under resting conditions just like a nerve fibre as soon as nerve impulses reach the terminal end of the axon, small sacs called synaptic vesicles to fuse with the axon membrane and release a chemical transmitter, acetylcholine. • Acetylcholine diffuses across the synaptic cleft and binds to the receptor sites of the motor and plate.• As soon as depolarization of the motor end plate reaches and plate reaches a certain level, it creates an action potential. After this, an enzyme cholinesterase present along with the receptor sites for acetylcholine breaks down acetylcholine into acetate and choline. • The area of contact between a nerve and muscle fibre is called motor end plate or muscular junction.• Calcium plays a key regulatory role in muscle contraction. These ions bind to troponin causing a change in its shape and position. This, in turn, alters and the position of tropomyosin. This shift exposes the active sites on the F-actin and myosin cross-bridges are then able to bind these active sites. • The head of each myosin molecule contains an enzyme myosin ATPase. In the presence of myosin ATPase, calcium ions and Magnesium ions, ATP breaks down into ADP and inorganic phosphate and some amount of energy.• Energy from ATP causes energized myosin, cross bridges to bind to actin. The energized cross bridge move causing thin myofilaments to slide along the thick myofilaments.

Q67. Lipids store double the amount of energy as compared to carbohydrates because of:

• A. High proportion of oxygen
• B. High C-O ratio
• C. Low proportion of Carbon
• D. High proportion of C-H✓

Explanation: The normal oxidative process yields approximately 9 kcal per gram of fats, and approximately 4 kcal per gram for carbohydrates. Lipids are generally more “fully reduced” from a chemical perspective as they have significantly more C-C and C-H bonds and the energy is stored within these bonds. Under a normal oxidative process, these bonds are broken in the presence of oxygen to yield carbon dioxide, water, and energy (exothermic reaction).

Q68. The primary oocyte in mammals has which of the following structures around it:

• A. Zona Pellucida✓
• B. Zona Vasculosa
• C. Zona Radiata
• D. None of them

Explanation: This is the following solution:

Q69. Coagulated protein is:

• A. Insoluble
• B. Non folded
• C. Nonfunctional
• D. All of above✓

Explanation: Coagulated protein is insoluble, non-folded, and non-functional.

Q70. For every 3 molecules of carbon dioxide in Calvin cycle how much G3P is produced?

• A. 6✓
• B. 5
• C. 3
• D. 8

Explanation: An enzyme, RuBisCO, catalyzes the fixation reaction, by combining CO2 with RuBP. The resulting six-carbon compound is broken down into two three-carbon compounds, and the energy in ATP and NADPH is used to convert these molecules into G3P.

Q71. Which of the following molecule facilitate the entry of HIV in human body

• A. Glycoprotein✓
• B. Liposomes
• C. Polysaccharides
• D. Lipopolysaccharides

Explanation: The HIV virus attaches to the host cell by the association of a surface glycoprotein to the CD4 molecule;To infect cells, the HIV protein envelope (Env) binds to the primary cellular receptor CD4 and then to a cellular coreceptor. This sequential binding triggers fusion of the viral and host cell membranes, initiating infection.

Q72. Which of the following is a chemical link between catabolism and anabolism?

• A. AMP
• B. ADP
• C. ATP✓
• D. All of these

Explanation: Adenosine Triphosphate, or ATP, is a molecule that carries energy within cells. It is often referred to as the "energy currency" of the cell because it provides the energy necessary for various cellular processes. ATP is composed of adenine (a nitrogenous base), ribose (a sugar), and three phosphate groups.

Q73. Antibodies are

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

Explanation: Immunoglobulins are large molecules made up of four peptide chains. It contains two identical heavy chains and two identical light chains, thus forming a tetrameric quaternary structure. The two heavy chains are linked to each other and to a light chain each by disulfide bonds. The resulting tetramer has two identical halves, which together form the Y-like shape. (It must be remembered that antibodies have FOUR polypeptide chains hence it must have a quaternary structure)

Q74. The number of vertebrate in horse neck are:

• A. 5
• B. 6
• C. 7✓
• D. 10

Explanation: Refer to the image below to help memorise.

Q75. What will happen if ligaments are torn ?

• A. Bones will move freely at joint and no pain.
• B. Bone less movable at joint and pain.✓
• C. Bone will become unfixed.
• D. Bone will become fixed.

Explanation: Ligaments join a bone with another bone in movable/synovial joints. Torn ligaments make movement at joints very painful and restricted.

Q76. Secondary oocyte is ovulated from:

• A. Corpus luteum
• B. Graafian follicle✓
• C. Primary follicle
• D. Germinal epithelium

Explanation: Ovulation is the release of eggs from the ovaries. In women, this event occurs when the ovarian follicles rupture and release the secondary oocyte ovarian cells. After ovulation, during the luteal phase, the egg will be available to be fertilized by sperm.

Q77. Which type of viruses infect E. Coli bacteria?

• A. T phages✓
• B. P phages
• C. Both
• D. None

Explanation: Escherichia virus (T4) is a species of bacteriophages that infect Escherichia coli bacteria. Thus, option A is correct.

Q78. Muscle contraction depends on:

• A. Nerve impulse
• B. Energy
• C. Calcium
• D. All of these options are correct✓

Explanation: Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron. The source of energy that is used to power the movement of contraction in working muscles is adenosine triphosphate (ATP). Ca2+ ions play an important role in muscle contraction by creating interactions between the proteins, myosin, and actin. The Ca2+ ions bind to the C component of the actin filament, which exposes the binding site for the myosin head to bind to in order to stimulate a muscle contraction.

Q79. The diagram shows a molecule. Which substance might include the above molecule?

• A. Cellulose
• B. Serine
• C. Glucose
• D. Alanine✓

Explanation: This is the structure of an amino acid. It contains an alpha carbon, an amino group, a hydrogen atom, an aldehyde group, and a side chain(-R). Option B and D are amino acids. Serine consists of a side chain of hydroxymethyl group, and Alanine has a methyl group. According to the given figure, option D is the correct option: A) Cellulose is a carbohydrate. B) Serine has a hydroxymethyl group as the side chain. C) glucose is a carbohydrate. D) Alanine is the correct answer.

Q80. A bacteriophage consists solely of:

• A. DNA and protein✓
• B. RNA and protein
• C. RNA only
• D. Protein only
• E. DNA only

Explanation: Bacteriophages are composed of proteins that encapsulate DNA. It can be RNA and a protein too but the best choice here will be DNA and protein(since it is more common).

Q81. Asthma releases a compound named as:

• A. Histamine✓
• B. Heparin
• C. Epinephrine
• D. Antibodies

Explanation: Asthma is a chronic lung disease affecting people of all ages. It is caused by inflammation and muscle tightening around the airways, which makes it harder to breathe.

Q82. Which of the following joints would allow no movements?

• A. Synovial joint
• B. Ball and Socket joint
• C. Fibrous joint✓
• D. Cartilaginous joint

Explanation: Fibrous joints are also called fixed or immovable joints because they do not allow any movement. These joints are immovable as they have no joint cavity or space present between the bones. They are connected via fibrous connective tissue. There are three types of fibrous joints: sutures, syndesmoses, and gomphoses. Sutures are found only in the skull, An example of a syndesmosis is the joint of the tibia and fibula in the ankle, Gomphoses occur between teeth and their socketsSo, the correct answer is 'Fibrous joint'

Q83. In a typical menstrual cycle of 28 days, what is the most likely fertile period?

• A. Days 5 to 10
• B. Days 1 to 5
• C. Days 14 to 15
• D. Days 11 to 14✓

Explanation: Ovulation occurs during days, 14th and 15th. The sperm is capable of surving in the uterus for about 3 days. Hence from 'day 11', the fertility period starts.

Q84. What is the length of spinal cord?

• A. 10-20 cm
• B. 20-30 cm
• C. 40-50 cm✓
• D. 60-90 cm

Explanation: The spinal cord is about 18 inches (45 centimetres) in length and is relatively cylindrical. The cervical (neck) and lumbar (lower back) segments house the spinal cord's two areas of enlargement. A fibrous band called the film terminal begins at the tip of the conus medullaris and extends to the pelvis.

Q85. In a human female, when does the fertilized egg get implanted in the uterus?

• A. After about 7 days of fertilization✓
• B. After about two months of fertilization
• C. After about three weeks of fertilization
• D. After about 30 days of fertilization

Explanation: Once the embryo reaches the blastocyst stage, approximately five to six days after fertilization, it hatches out of its zona pellucida and begins the process of implantation in the uterus.

Q86. When an electron jumps from n = 5 to n = 2 having wave number equal to 2.3 x 16 m-1. In which spectral series will it fall?

• A. Lyman
• B. Balmer✓
• C. Visible
• D. Infrared

Explanation: Correct option is B. The Balmer series is the name given to a series of spectral emission lines of the hydrogen atom that result from electron transitions from higher levels down to the energy level with principal quantum number 2.

Q87. Which one of the following has the highest lattice energy?

• A. NaCl
• B. KCl
• C. KBr
• D. LiCl✓

Explanation: The lattice enthalpy is the enthalpy change involved in the formation of an ionic compound from gaseous ions (an exothermic process). The Lattice energy is directly proportional to the charges of the ions but inversely proportional to the radii of the ions or more generally the distance between ions. Lattice Energy α (charge of ion/radius of the ion). As we go down in a group (Group 1 and 7 in this case), ionic radius increases, and as the net charge is constant (+1 and -1 respectively), the lattice energy of their compounds decreases. Order of cation radius: K+> Na+> Li+ Order of anion radius: Br-> Cl- Hence, the compound LiCl will have the greatest Lattice energy as both the ions have the least radius. Note: Across a period from left to right as the charge on ion increases, lattice energy increases.

Q88. The electrolysis of acetate solution produces ethane according to reaction: 2CH3COO- --> C2H6(g) + 2CO2(g) + 2e- The current efficiency of the process is 80%. What volume of gases would be produced at 27oC and 740 torr, if the current of 0.5 amp is passed through the solution of 96.45 min?

• A. 6.0 L
• B. 0.60 L
• C. 1.365 L
• D. 0.91 L✓

Explanation: Correct option is 'D'. Equivalents of CO2 produced =(I×η)×t/96500 =0.5×0.8×96.5×6096500=0.024 moles of CO2(n=1) produced =0.024 moles of C2H6(n=2) produced =0.024/2=0.012 Total moles of gases produced ⇒0.036 Vgases=nRT/P=0.036×0.0821×300/(740/760)=0.91L

Q89. The paramagnetic character of a substance is due to:

• A. Bond pairs of electrons
• B. Lone pairs of electrons
• C. Unpaired electrons in atom or molecule✓
• D. Paired electrons in valence shells of electrons

Explanation: Paramagnetism is due to the presence of unpaired electrons in the material, so most atoms with incompletely filled atomic orbitals are paramagnetic.

Q90. In the methane structure, each of the four valence electrons pairs up with the sole electron of hydrogen and shows:

• A. AB₄ type with two lone pairs
• B. AB₄ type with no lone pair✓
• C. AB₄ with no bond pair
• D. AB₄ with one lone pair

Explanation: In a methane molecule, the four valence electrons of carbon are each paired with one electron of hydrogen. It has four bond pairs and no lone pair. The molecule shape is of AB4 type.

Q91. Which one of the following molecules has the shortest distance of carbon atoms?

• A. CH3 - CH3
• B. CH2 = CH2
• C. CH ≡ CH✓
• D. CH3 - CH2 - CH3
• E. CH2 = CH2 - CH3

Explanation: The more the number of bonds the lesser will be the bond distance. Since the CH ≡ CH has the most number of bonds between two carbon atoms, it has the shortest bond length.

Q92. Which of the following is TRUE regarding Methyl Alcohol?

• A. It is a colorless, volatile, thin liquid with specific gravity 0.796 at 15°C.✓
• B. It is used for low-temperature thermometers and as a fuel substitute.
• C. It is extensively used in the formation of different beverages.
• D. It is used as a base for perfumes
• E. It is used as an antiseptic and disinfectant

Explanation: Properties of Methyl Alcohol include: -Colourless -Volatile -Thin liquid with a specific gravity of 0.796 at 15°C. Methyl alcohol is not an effective sanitizer. Since it is toxic and can readily be absorbed under the skin it is never used as a perfume. For the same reason not used to make beverages. It is not used in thermometers. Options B and C are the characteristics of Ethanol. Option D represents esters. Option E represents Phenol.

Q93. Addition of 2% gypsum in cement:

• A. Triggers hydration
• B. Triggers hydrolysis
• C. Prevents rapid hardening✓
• D. All of the above options are correct

Explanation: Portland cement is made by strongly heating a finely powdered mixture of clay and limestone. The final product, known as clinker, is cooled and then ground into a very fine powder. During the grinding, there is added about 2% of gypsum which prevents the cement from hardening too rapidly. The addition of gypsum increases the setting time of cement.Hence, C is the correct option.

Q94. Which of the following is not a physical property of ethers?

• A. They are usually volatile liquids
• B. Show weak hydrogen bonding
• C. They are highly flammable with low boiling points
• D. It is poisonous and is used as a disinfectant in hospitals✓

Explanation: All of the properties except poisonous and disinfectants are physical properties of ethers. Phenol is considered poisonous and is used as a disinfectant.

Q95. The maximum number of electrons that an orbital can accommodate is/are:

• A. 0
• B. 1
• C. 2✓
• D. 3
• E. 4

Explanation: The maximum number of electrons in a single orbital is two. The maximum number of electrons an orbital can accommodate is 2. As in an orbital two electrons can never have the same values of all 4 quantum no.s according to Pauli’s exclusion principle. So to follow this rule, an orbital can accommodate 2 electrons only.

Q96. A compound has an empirical (simple) formula, C2H2O. If the experimental molecular weight is found to be in the range 160-170, the molecular formula of this compound is: (Atomic weight: C = 12.1, H = 1.008, O = 16).

• A. C3H6O3
• B. C4H4O2
• C. C8H8O4✓
• D. C6H6O3

Explanation: The empirical formula mass is 42 i.e. [2(12) + 2(1) +16]. Multiplying the empirical formula mass by 4 will result in a molecular mass of 168, which is between 160 and 170, and would give us the molecular mass of C8H8O4.

Q97. Sp³ hybridization is also called as_?

• A. Octahedral hybridization
• B. Trigonal hybridization
• C. Linear hybridization
• D. Tetragonal hybridization✓

Explanation: One s orbital and three p orbitals hybridize to form four sp³ orbitals, giving it a tetragonal shape.

Q98. Which of the following values of heat of formation indicates that the product is least stable?

• A. - 94 kcal
• B. + 21.4 kcal
• C. - 231 kcal
• D. + 64.8 kcal✓

Explanation: In the context of heat of formation (ΔH), a negative value indicates that the formation of the compound is exothermic, meaning the compound is more stable compared to its constituent elements in their standard states.So, the least stable compound among the options provided would have the most positive (ΔH) value and option d has the most positive value ,hence that is the correct option.

Q99. If the absolute temperature of a gas is reduced to one half and the pressure is doubled, the volume of gas will be:

• A. Increased four times
• B. Decreased four times✓
• C. Remained unchanged
• D. Reduced to one half
• E. Increased two times

Explanation: This is the following solution.

Q100. A sample of gas weighs 1.25 g, at 28 C occupying a volume of 250 ml and its pressure is 715 torr. What is the molar mass in grams?

• A. 131.1✓
• B. 1.311
• C. 1.212
• D. 122.1

Explanation: Mass of gas = 1.25 g Volume of gas = 250 ml= 0.25 L as (1 L = 1000 ml) Pressure of gas = 715 torr The temperature of gas = Gas constant, R = 62.364 L torr/mol K Using the ideal gas law, PV=nRT PV=(m/M)RT M=mRT/PV where, M = Molar mass of gas W = Mass of gas R = gas constant T = temperature of gas P = Pressure of gas V = Volume of gas Now put all the given values in the above formula, we get the value of the molar mass of gas. M=(1.25)(62.364)(301)/(715)(0.25) M=131.1M

Q101. Which of the following reaction has greater Kp than Kc?

• A. 2NO + Cl2 <-> 2NOCl
• B. 2SO2 + O2 <-> 2SO3
• C. 2NOCl <-> 2NO + Cl2✓
• D. N2 + 3H2 <-> 2NH3

Explanation: When the volume of products is greater than the volume of reactants, then Kp> Kc. From the options above, only Option C has more volume of gases at the product side as compared to the reactant side. We concluded this from the mole ratio of the equation which is 3 on the product side against 2 on the reactant side.

Q102. Which of the following compounds will give a secondary alcohol after reaction with NaBH4?

• A. CH3COCH3✓
• B. CH3COOCH3
• C. CH3CH2CHO
• D. CH3CH2COOH

Explanation: Option A is a ketone, and its reduction (NaBH4 is a reducing agent) results in a secondary alcohol. This is because the carbonyl functional group is present in the middle of the chain so, the hydroxyl group is formed in the same place after reduction, giving a secondary alcohol. Option B is an ester, which does not undergo reduction with NaBH4.Option C is an aldehyde, that forms a primary alcohol, upon reduction, as its carbonyl group is towards the terminal end of the chain, thereby forming a terminal hydroxyl group. Option D is a carboxylic acid, which does not undergo reduction with NaBH4.

Q103. The increase in size of an anion is due to Increase in repulsion of ?

• A. Electron-proton
• B. Electron-electron✓
• C. Electron-nucleus
• D. Proton-nucleus

Explanation: Option B is correct because: In an anion the extra electron or electrons are repelled by the electrons in the lower orbits and as a result the distance between the nucleus and valence electron increases increasing the size of the anion. Option A is incorrect because: Electron and proton attract. Option C is incorrect because: electron and nucleus attract. Option D is incorrect because: There is no attraction or repulsion between proton and neutron.

Q104. Le-Chatelier Principle is about

• A. Reaction Mixture
• B. Reactants
• C. Equilibrium Mixture✓
• D. Products

Explanation: Le Chatelier’s Principle states that ‘for a system in equilibrium, if a change in conditions takes place, the position of equilibrium shifts to counteract that change.

Q105. When the number of moles of reactants and products are equal in reversible reactions which parameter would not affect at equilibrium?

• A. Temperature
• B. Pressure
• C. Volume
• D. Catalyst✓

Explanation: The addition of catalysts does not alter the equilibrium. Catalysts only help in achieving the equilibrium quicker. Option B and C would be correct only if all the products and reactants were gases, however the question does not specify that, hence option D is the best to choose. For change in temperature, the equilibrium remains in its new position, favoring the endothermic reaction if the surrounding temperature is high or favoring the exothermic reaction if the surrounding temperature is low.

Q106. For which of the following order of the reaction, rate of reaction is inversely proportional to the concentration reaction?

• A. 1st order reaction
• B. 2nd order reaction✓
• C. Negative order of reaction
• D. Zero order of reaction

Explanation: The rate of reaction is inversely proportional to the concentration of the reactant in a second-order reaction (option b). In first-order reactions, the rate is directly proportional to the concentration, while in zero-order reactions, the rate is independent of the concentration. Negative order of reaction is not a recognized concept in chemical kinetics.The rate of a second-order reaction is inversely proportional to the initial concentration of reactants. This means that if the concentration of a reactant is doubled, the rate of the reaction will also double. The half-life of a second-order reaction is also inversely proportional to the initial concentration of the reactant.

Q107. The rate constant k is 0.693min-1. The half life for the first order reaction will be

• A. 1 min✓
• B. 0.693 min
• C. 2 min
• D. 4 min

Explanation: Half life of 1st order reaction is given as ( t1/2 ) 0.693 / k = 0.693 / 0.693 =1 min

Q108. Which of the following factor(s) affect a reversible chemical reaction in accordance with the Le - Chatelier Principle?

• A. Pressure
• B. Temperature
• C. Concentration
• D. Pressure, concentration and temperature✓

Explanation: Le Chatelier’s principle states that changes in the temperature, pressure, volume, or concentration of a system will result in predictable and opposing changes in the system in order to achieve a new equilibrium state. If gases are present in the reaction mixture,difference in the number of moles on either side of the equation can shift the equilibrium to the side with less moles if the pressure is increased Increasing the temperature for an exothermic reversible reaction decreases the yield. Increasing the concentration of the reactants can increase the yield as equilibrium shift to the product side. Using the Haber Process as an example:

Q109. According to Pauli's exclusion principle, both electrons in a degenerate orbital have:

• A. Same spin
• B. Same values of all four quantum numbers
• C. Opposite spin✓
• D. Same value for spin quantum number

Explanation: Pauli's exclusion principle states that no two electrons in a single atom can have the same values for all four quantum numbers. According to this, if two electrons are in the same degenerate orbital, they can have the same value for the principal quantum number, Azimuthal quantum number, and magnetic quantum number but not for spin quantum number. This is why these electrons have opposite spins.

Q110. The following reaction is an example of:

• A. Alkylation of benzene
• B. Acylation of benzene✓
• C. Oxidation of benzene
• D. Halogenations of benzene
• E. ABoth A and B

Explanation: Since the acyl group is added to the benzene as a result of this reaction process we can say that it is an acylation of benzene.

Q111. The effect of temperature on the rate of a reaction is given by:

• A. Henderson’s equation
• B. General gas equation
• C. Arrhenius equation✓
• D. Van der Waals equation

Explanation: In physical chemistry, the 'Arrhenius equation' is a formula for the temperature dependence of reaction rates- k= Ae(-Ea/RT) where A= Arrhenius constant, Ea= activation energy, R= universal gas constant, T= absolute temperature. So, C stands correct. 'Henderson’s equation' is used to calculate the pH of the buffer solution, not the effect of temperature on reaction rates. The general gas equation and Van Der Waals equation are both used to study the changes in the volume of ideal gases at different pressures and temperatures. Both of these equations have nothing to do with reaction rates.

Q112. Which of the following reagent is used to separate and purify carbonyl and non carbonyl compounds?

• A. HCN
• B. BrMgCH3
• C. NaHSO3✓
• D. H2O

Explanation: When a saturated solution of sodium hydrogen sulphite also called sodium bisulphite is mixed with an impure carbonyl compound, it produces an additional compound with white crystals. That is why sodium bisulphite is used for purification of carbonyl compounds from non carbonyl compounds.

Q113. Transfer of heat from hot surroundings to a cold refrigerator is an example of:

• A. Spontaneous reaction✓
• B. Non-Spontaneous reaction
• C. First law of thermodynamics
• D. All of the above options are correct

Explanation: Spontaneous heat transfer from hot to cold is also known as the second law of thermodynamics. The second law of thermodynamics states that the total entropy of an isolated system (the thermal energy per unit temperature that is unavailable for doing useful work) can never decrease.A spontaneous reaction is a reaction that favors the formation of products at the conditions under which the reaction is occurring. A bonfire is an example of a spontaneous reaction, since it is exothermic (there is a decrease in the energy of the system as energy is released to the surroundings as heat).

Q114. If the difference between electronegativity values between two atoms is less than 1.7 , the bond is necessarily:

• A. Ionic
• B. Covalent✓
• C. Electrovalent
• D. Polar
• E. Non - polar

Explanation: If the electronegative difference is >1.7 then its nature is ionic and <1.7 then its nature is covalent and if its equal to 1.7 then nature of bond will be 50% ionic and 50% covalent.

Q115. The Electronic Probability distribution is affected by:

• A. Nucleus of the atoms
• B. Atomic number✓
• C. Number of atoms
• D. None of the above

Explanation: From the explanation below (PTB I, p. 141), the most suitable choice is "atomic number" because higher atomic number means a greater distance of an electron from the nucleus, and therefore lower electron probability distribution.

Q116. The unit of rate constant is same as that of rate of reaction in:

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

Explanation: The rate equation is expressed as: rate=k[A]x k=rate constant [A]= concentration of reactant A x=order of reaction with respect to reactant A For zero order reaction, x=0 As rate = d[A]/dt d[A]/dt = k[A]0 d[A]/dt = k = M/s

Q117. Alkaline earth metal oxides react with water to give hydroxides. The solubility of alkaline earth metal oxides in water increases as we move from top to bottom in a group. Which of the following alkaline earth metal oxides is least soluble in water?

• A. MgO✓
• B. CaO
• C. BaO
• D. SrO

Explanation: Solubility of alkaline earth metal oxides in water increases as we move from top to bottom because lattice energy decreases faster than hydration energy. For the compound to be soluble, its hydration energy must be greater than its lattice energy. Mg is at the top of the group (followed by Ca, Sr, and then Ba), Magnesium oxide (MgO) has low solubility in water. It reacts with water to form magnesium hydroxide Mg(OH)2, but the solubility is relatively limited.

Q118. Which of the following will not undergo aldol condensation?

• A. Acetaldehyde
• B. Propanaldehyde
• C. Formaldehyde✓
• D. Trideuteroacetaldehyde

Explanation: The aldehydes that have alpha hydrogen atoms undergo aldol condensation reaction

Q119. A student mixed ethyl alcohol with a small amount of sodium dichromate and added it to the hot solution of dilute sulphuric acid. A vigorous reaction took place. He distilled the product formed immediately. What was the product?

• A. Acetone
• B. Acetic acid
• C. Dimethyl ether
• D. Acetaldehyde✓

Explanation: Acetaldehyde is the product of the described reaction. The oxidation of ethanol with sodium dichromate and dilute sulfuric acid results in the formation of acetaldehyde as an intermediate product. Acetaldehyde is an aldehyde and is often further oxidized to acetic acid under more vigorous conditions or in the presence of excess oxidizing agents.

Q120. If the energy of activation of a chemical reaction is very low, the rate of that chemical reaction is observed to be very high because?

• A. Concentration of the reactants becomes irrelevant
• B. Reaction proceeds without any transition state
• C. Number of efficient or fruitful collisions increase✓
• D. Molecules of the reactants move slowly

Explanation: Option A is incorrect because the concentration of reactants, still, is a factor regardless of other factors such as low activation energy. (Same goes for all other factors that affect the rate of reaction) Option B is incorrect, as the transition state is always present regardless of activation energy. Option C is correct, as low activation energy means that many more reactant particles have the minimum energy required to produce products so, with a greater number of particles possessing energy equal to or greater than the activation energy collide, they produce products. Hence, more fruitful collisions occur. Option D is incorrect, as reactant particles move slowly if there is less heat energy applied, which was not mentioned in the question.

Q121. An unknown alkene was treated with ozone followed by zinc dust in dilute acetic acid. The reaction products were determined to be acetone and propanal. What is the structure of the unknown alkene?

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

Explanation: Ozonolysis of alkene: Ozonolysis is a method of oxidatively cleaving alkenes or alkynes using ozone (O3), a reactive allotrope of oxygen. The process allows for carbon-carbon double or triple bonds to be replaced by double bonds with oxygen. The third compound gives propanaldehyde and acetone on ozonolysis. So the reactant will be the compound depicted in Option C.

Q122. What one is the correct geometry of acetal?

• A. Trigonal
• B. Linear
• C. Tetrahedral✓
• D. Square planer

Explanation: Option C is correct as acetal is the product of condensation of two alcohol molecules with an aldehyde to form a "tetrahedral structure".

Q123. In the addition of sodium bisulfite to carbonyl system, which of the following is a nucleophile?

• A. Sulphide ion
• B. Sulfite ion✓
• C. Hydride ion
• D. Sodium ion

Explanation: The addition of sodium bisulfite to a carbonyl group takes place as follows:Sodium bisulfite ionizes to form sulfite ions.The sulfite ion acts as a nucleophile, since the sulfur atom is more nucleophilic than oxygen, a C-S bond is formed.Proton is attached to the negatively charged sulfur atom to form a bisulfite addition product.

Q124. Purification of table salt (NaCl) by passing HCl gas through its saturated aqueous solution is an example of:

• A. Law of mass action
• B. Hess’s law
• C. Common ion effect✓
• D. Henry’s law

Explanation: In saturated solution of NaCl,equillibrium is established between ions and unionised NaCl. NaCl ⇌ Na+ + Cl- When HCl gas is passed through a saturated solution of NaCl, it is completely dissociated to form H+ and Cl- ions. HCl —>H+ + Cl- Cl- ion is common to both electrolytes, hence Cl- ion concentration in solution increases. According to Le-chatelier’s principle, the position of the equilibrium gets shifted to the left side. Hence the ionization of NaCl gets suppressed and the deposition of NaCl takes place.

Q125. The flame colour of Ca in flame test is:

• A. Orange red✓
• B. Golden yellow
• C. Red
• D. Pink

Explanation: The flame of Ca is orange-red so, A is the correct option. A yellow flame is of Sodium (Na), Red flame is of Lithium (Li), and Pink flame is of Potassium (K) thus B, C, and D are incorrect.

Q126. Which enthalpy change is relevant in the following process Na(s) -> Na (g) ΔH = +107

• A. Enthalpy of atomization✓
• B. Enthalpy of fusion
• C. Enthalpy of vaporization
• D. Enthalpy of formation

Explanation: Option A, enthalpy of atomization, is the energy required to completely separate all the atoms in a chemical substance. The separated atoms are in a gaseous state and get separated from the corresponding substance in its standard state. Sodium is solid in its standard state, and after atomization, the atoms are in their gaseous state. Hence, this is the correct answer. Option B is the enthalpy change when a solid substance melts into a liquid. Here, the state change is from a solid to a gas, no liquid state involved.Option C is the enthalpy change when a liquid is vaporized into a gas. Here, a solid is atomized to its gaseous state so, vaporization does not apply here.Option D is the enthalpy change when one mole of a substance is formed from its constituent elements. This does not describe the given reaction.

Q127. In a galvanic cell Copper compartment get net negative charge due to arrival of _.

• A. Free charge
• B. Electron✓
• C. Protons
• D. Zinc ions

Explanation: Option B Cu+2 ions from the solution pick up the ELECTRONS at Cu electrode and get reduced to copper atoms ,hence Cu acts as a cathode and the compartment gets net negative charge.

Q128. Physical properties of Ethyne is/are:

• A. It is colourless gas with a sweet smell.
• B. It is sparingly soluble in water.
• C. It is less dense than air.
• D. It explodes on compression to a liquid because of unstable nature.
• E. All of the above✓

Explanation: Following are all the properties of the ethyne gas:

Q129. London forces are present in

• A. ammonia
• B. water
• C. kerosene oil✓
• D. HCl

Explanation: London forces are present in kerosene oil. The London dispersion force is caused by random and temporary changes in the polarity of atoms, caused by the location of the electrons in the atoms' orbitals.

Q130. The first ionization potential of alkaline earth metal is greater than alkali metals because _.

• A. They are more reactive
• B. They have greater atomic radii
• C. They have smaller atomic sizes✓
• D. All of the above

Explanation: In general, as we move from left to right in a period, the ionization energy of the elements increases due to successive increase in the nuclear charge and decrease in atomic size.

Q131. For the purification, impure copper is made the:

• A. Cathode
• B. Anode✓
• C. Solution
• D. Both Cathode and Anode

Explanation: Copper is purified by electrolysis . Electricity is passed through solutions containing copper compounds, such as copper sulfate. The anode (positive electrode ) is made from impure copper and the cathode (negative electrode) is made from pure copper.

Q132. The number of electrons present in n=2 , l = 1 and m = 1, 0, -1 are:

• A. 2
• B. 6✓
• C. 8
• D. 10
• E. 18

Explanation: l=1 refers to the p subshell, which can accommodate a maximum number of 6 electrons.

Q133. Which of the following substances has the largest intermolecular forces of attraction?

• A. H2O✓
• B. H2S
• C. H2Se
• D. H2Te

Explanation: The strongest intermolecular force is hydrogen bonding, which is a particular subset of dipole-dipole interactions .It occurs when a hydrogen atom is in close proximity to a highly electronegative atom; namely oxygen, fluorine, nitrogen etc. Among the given option only option A has hydrogen bond hence it is the correct answer.

Q134. Two rocket fuels below are determined by their high performance. N2H4(l) + O2(g) -> N2(g) + 2H2O(l) ΔH= -632 kJ H2 (g) + ½ O2(g) -> H2O(l) ΔH = -286 kJ If equal masses of hydrazine and hydrogen are used, which of the following has better performance?

• A. Hydrazine
• B. Both have equal enthalpy of formation
• C. Hydrogen gas✓
• D. Cannot be compared

Explanation: The performance of rocket fuel is measured by its enthalpy of combustion, which is the amount of heat released when one mole of the fuel is completely burned in excess oxygen to form its products at standard conditions. The enthalpy of the formation of hydrazine is -632 kJ/mol, and that of hydrogen gas is -286 kJ/mol. Since equal masses of hydrazine and hydrogen are used, we can compare their performances by calculating the amount of heat released per gram of fuel. >For hydrazine, the amount of heat released per gram of fuel is (-632 kJ/mol) / (32 g/mol) = -19.75 kJ/g. >For hydrogen gas, the amount of heat released per gram of fuel is (-286 kJ/mol) / (2 g/mol) = -143 kJ/g. Therefore, hydrogen gas has better performance as a rocket fuel than hydrazine since it releases more heat per gram of fuel.

Q135. The standard electrode potential of hydrogen is arbitrarily taken at 298 K is _

• A. 0.00 volt✓
• B. 0.10 volt
• C. 10.0 volt
• D. 1.00 volt

Explanation: The standard hydrogen electrode potential by conventional at 298 K is taken to be 0.00 volts.

Q136. The relative energies of 4s, 4p and 3d orbitals are in the order:

• A. 3d < 4p <4s
• B. 4s < 3d < 4p✓
• C. 4p < 4s < 3d
• D. 4p < 3d < 4s

Explanation: The Aufbau principle states that electrons fill lower-energy atomic orbitals before filling higher-energy ones (Aufbau is German for "building-up"). By following this rule, we can predict the electron configurations for atoms or ions. To find the energy of orbitals, we use the (n+l) principle where n= energy level, while l= orbital level. For 4s: n+l= 4 + 0 = 4For 3d: n+l= 3 + 2= 5For 4p: n+l = 4+ 1= 5 (but since the distance of 4p is greater than that of 3d, 3d gets filled first) Final order: 4s<3d<4p

Q137. The number of atoms present in a molecule determines its:

• A. Shape
• B. Size
• C. Molecularity
• D. Atomicity✓

Explanation: The correct answer is: Atomicity The number of atoms present in a molecule is referred to as its atomicity. It represents the total count of atoms bonded together within a molecule.

Q138. Select the reagent X from the following choices for this conversion:

• A. Acidified Potassium hydroxide
• B. Acidified Potassium dichromate (VI)✓
• C. Acidified Phosphoric acid
• D. Acidified Oxalic acid

Explanation: The reaction above is oxidation of a secondary alcohol into a ketone. As such, an oxidizing agent must be chosen for reagent X. Among the options, 'Potassium dichromate (VI)' is an oxidizing agent so, the correct option is B. Another answer could be 'potassium manganate (VII)', but it is not mentioned in any of the options. The other options do not oxidize alcohols.

Q139. If concentration time graph of a reactant indicates a constant half life, then the order reaction with respect to that reactant is:

• A. Zero order
• B. Half order
• C. Second order
• D. First order✓

Explanation: In First order reactions, the graph represents the half-life is different from zero order reaction in a way that the slope continually decreases as time progresses until it reaches zero. We can also easily see that the length of half-life will be constant, independent of concentration. For example, it takes the same amount of time for the concentration to decrease from one point to another point. The half-life of zero order reaction decreases as the concentration decreases. The half life of second order reactions increases as the concentration increases.

Q140. A body of mass 5 kg, projected at an angle of 45° from the ground covers a horizontal range of 45 m. The acceleration due to gravity is g = 10 m/s^2. What is the velocity with which it was projected?

• A. 22.5 m/s
• B. 20 m/s
• C. 19.8 m/s
• D. 21.21 m/s✓

Explanation: Explanation is given below.

Q141. Light, emitted by a single source, passes through 2 narrow slits 1.00mm apart. The interference pattern is observed on a screen 200 cm away and the separation between the centers of adjacent bright fringes is 2.00mm. What would be the wavelength of the light? (u= micro)

• A. 2 pm
• B. 1 um✓
• C. 2 um
• D. 1 nm

Explanation: All the values, pertaining to distance, would be converted to meters (m). Slit separation = 1 x 10-3m Fringe separation = 2 x 10-3m Distance between slit and screen = 200 x 10-2m

Q142. The following question belongs to the topic of motion:

• A. Average velocity
• B. Uniform velocity
• C. Instantaneous velocity✓
• D. Variable velocity
• E. None of the above

Explanation: When the change in time is brought to zero this makes the velocity maximum. Which is also called instantaneous velocity.

Q143. The current passing through a conductor is directly proportional to the potential difference applied across its terminals, provided the temperature and other physical conditions of the conductor does not change.

• A. Gauss's law
• B. Lenz's law
• C. Pascal's law
• D. Ohm's law✓

Explanation: Ohm’s law states that: The current passing through a conductor is directly proportional to potential difference applied across its terminal, provided the temperature and other physical conditions does not change.

Q144. Which of the following is the pair of isobars?

• A. 1H1 and 2H1
• B. 12C6 and 13H6
• C. 2H1 and 3H1
• D. 30H15 and 30Si14✓

Explanation: Isobars are atomic species that have the same mass number (A), but a different atomic number (Z). This can only be seen in option D. Isobars should not be confused with isotopes, which share the same atomic number, and therefore belong to the same chemical element, but have varying mass numbers.

Q145. The domestic electricity supply has a frequency of:

• A. 150 Hz
• B. 100 Hz
• C. 50 Hz
• D. 25 Hz✓

Explanation: The domestic electricity supply has a frequency of 50 Hz in Pakistan.

Q146. A car going around a certain curve at a speed of 25 km/h has a centripetal force acting on it of 100 N. If the speed of the car is doubled, the centripetal force:

• A. Is quadrupled✓
• B. Is doubled
• C. Is multiplied by the √2
• D. Is reduced to ½ of the original value
• E. Is reduced to ⅙ of the original value

Explanation: a=v^2/r Where a is centripetal acceleration and v is linear velocity and r is the radius. When velocity is doubled the centripetal acceleration will be quadrupled.

Q147. Diffraction is prominent when the wavelength of light is:

• A. five time small as compared with the size of the obstacle
• B. large as compared with the mass of the obstacle
• C. Large as compared with the size of the obstacle✓
• D. one half as compared with the size of the obstacle

Explanation: Diffraction is prominent only when the wavelength of light is large as compared with the size of the obstacle.

Q148. In a circuit, there is a current of 5 amp which is changed such that the current falls to zero in 0.1 sec. If an average e.m.f. of 200 volts is induced, the self-inductance of the circuit will be:

• A. 4 Henrys✓
• B. 5 Henrys
• C. 6 Henrys
• D. 7 Henrys
• E. 8 henrys

Explanation: Attached below is the solution of question above:

Q149. When two bodies approach each other at constant speed, the distance between them decreases at the rate of 6m/sec. If they move away in the same direction, the distance between them increases at the rate of 4 m/sec. Calculate their velocities.

• A. 5 m/sec, 1 m/sec✓
• B. 3 m/sec, 3 m/sec
• C. 6 m/sec, 1 m/sec
• D. 4 m/sec, 2 m/sec

Explanation: Let's name the two unknown speeds as V1 and V2. From the information given, V1+V2 = 6 V1 - V2 = 4 Solving the equations simultaneously, V1 = 4 + V2 Substituiting this in first equation, 4 + V2 + V2 = 6 2V2 = 2 V2 = 1 m/s V1 = 4 + V2 V1 = 4 + 1 V1 = 5 m/s. Option A is the correct answer.

Q150. There are two charges +2𝜇𝐶 and -3𝜇𝐶 the ratio of the force acting on them will be:

• A. 3 ∶ 1
• B. 1 ∶ 1✓
• C. 11 ∶ 8
• D. 3 ∶ 8

Explanation: Apply equation F=Eq

Q151. Galilean's law is applied to:

• A. Frame of reference
• B. Inertial frames✓
• C. All frames
• D. Non-inertial frames

Explanation: Galiliean's law states that all laws of motion are the same in inertial or non-accelerating frames. A frame of reference may be inertial or non-inertial.

Q152. Wave nature of electron resembles:

• A. None of these
• B. Beta rays✓
• C. Alpha rays
• D. Gamma rays

Explanation: Beta radiation consists of a high-energy and high-speed electron or positron (a positively charged particle with the same mass as an electron). The wave nature of electrons most closely resembles beta rays.

Q153. In the direction indicated by an electric field line:

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

Explanation: c) The potential must decrease:This option suggests that in the direction indicated by an electric field line, the electric potential must decrease. This is generally true. Electric field lines point in the direction of decreasing electric potential. Therefore, when following the direction of an electric field line, you are moving from a region of higher potential to a region of lower potential.

Q154. Energy consumed by 60 watt bulb in 2 minutes is equal to:

• A. 7.2 kilo joules✓
• B. 720 joules
• C. 120 joules
• D. 72000 joules

Explanation: 60 watt * 120s (2 mins) = 7200 watt-seconds = 7200J = 7.2 Kilo joules.

Q155. F = e(v x B) is valid for:

• A. Electron
• B. Proton✓
• C. Neutron
• D. All of these options are correct

Explanation: Lorentz Force is only valid for protons, because the direction of conventional current is assumed to be the movement of positive particles.If electrons are being discussed a negative sign is added to the equation but as in the question there is no negative sign therefore it is only valid for protons.

Q156. The detection and estimation of an element in a mixture is sometimes nearly impossible, if it is present in very minute traces or if it’s chemical properties are very similar to those of other elements in the mixture. An effective technique is developed for these purposes is known as?

• A. Simple Analysis
• B. Spectral Analysis
• C. Activation Analysis✓
• D. Geometric Analysis
• E. Mechanical Analysis

Explanation: Activation analysis (AA) is an analytical method for determining the (stable isotope) concentration of trace elements in the bulk of a sample.

Q157. Three resistors of resistance R1, R2 and R3 are connected as shown in figure.Equivalence resistance is:

• A. Option A
• B. Option B
• C. Option C
• D. Option D
• E. None of the above✓

Explanation: (All options are wrong) R2 and R3 are connected in parallel, so their total resistances would be RT=(R2R3)/(R2+R3). And then R1 is connected in series so the equivalence resistance would be the sum of R1 and the total resistance in the parallel resistors, which would be R1+((R2R3)/(R2+R3)) which equals to (R1R2+R2R3+R3R1)/(R2+R3)

Q158. Radar is an application of which effect?

• A. Doppler's effect✓
• B. Magnetic effect
• C. Mechanical effect
• D. Electrical effect

Explanation: Doppler Effect refers to the change in wave frequency during the relative motion between a wave source and its observer. Doppler effect is used to measure speed in RADAR sensors. When the fixed-frequency radio wave sent from the sender continuously strikes an object that is moving towards or away from the sender, the frequency of the reflected radio wave will be changed which is why the answer is A.

Q159. A neutron travels a distance of 24 m in a time interval of 3.6 x 10^-4 s. Assuming its speed was constant. Find its kinetic energy. Take 1.7 x 10^-27 kg as the mass of the neutron.

• A. 37.702 x 10^-19 joule✓
• B. 27.702 x 10^-19 joule
• C. 17.70 x 10^-19 joule
• D. 07.702 x 10^-29 joule

Explanation: speed of neutron = distance travelled by neutron / time taken by neutron for covered that distance . speed of neutron = 24/3.6 × 10-4 m/s speed of neutron ( V)= 6.6 × 10⁴ m/s now , kinetic energy = 1/2mv² K.E = 1/2 × 1.7 × 10-27 ×( 6.6 × 10⁴)² J = 1/2 × 1.7 × (6.6)² × 10-19 j =37.2 × 10-19 j so, K.E = 37.2 × 10-19. Hence the correct answer is A which is closest to the correct answer

Q160. Kirchhoff's first law/rule corresponds to:

• A. Law of conservation of energy
• B. Law Of conservation Of momentum
• C. Law of conservation of charge✓
• D. Law of conservation of mass

Explanation: Kirchhoff's first law states that the algebraic sum of current flowing into a junction is zero. This rule corresponds to conservation of charge which states that total charge in a closed system remains constant because current is the rate of flow of charge.

Q161. Assume that you have two balls of Identical volume, one weighing 2 Newtons and the other 10 Newtons. Both are falling freely after being released from the same point simultaneously. Which of the following will then be true: I. The 10 N ball falling freely from rest will be accelerated at a greater rate than the 2 N ball II. At the end of the 4s of freefall, the 10 N ball will have 5 times the momentum of the 2 N ball III. At the end of the 4s of free fall, the 10 N ball will have the same kinetic energy as the 2 N ball IV. The 10 N ball possesses greater inertia than the 2 N ball

• A. I, Il and Ill only
• B. I and II only
• C. II and IV only✓
• D. IV only
• E. None of these

Explanation: Acceleration of free fall acts equally on all masses, this is why both objects despite having different masses have the same speed at any point in time. Statement II is correct because two objects have the same velocity but one having 5 times more mass than the other will have 5 times more momentum than the other object. Statement IV is also correct because inertia depends upon mass since a 10N ball has a higher mass it will have greater inertia. Statement III is wrong because objects have different masses so their kinetic energy can not be the same. Statement I is wrong because objects accelerate irrespective of their masses as mentioned before.

Q162. The flow of charges produce:

• A. Current only
• B. Magnetic field only
• C. Electric field only
• D. All of the above✓

Explanation: A stationary charge produces only electric field whereas a moving charge produces both electric as well as magnetic fields and also current.

Q163. A black body _ black body radiation.

• A. Emits
• B. None of these
• C. Both emits and absorbs✓
• D. Absorbs

Explanation: A black body is a perfect absorber that absorbs all kinds of radiation. However, when it is heated, it becomes a very effective emitter of radiation called black body radiation. The absolute temperature of the black body and the wavelength of the radiation emitted are indirectly proportional to each other according to Wien's law which stipulates:

Q164. The electric flux through the surface of the sphere is directly proportional to the:

• A. Surface area of the sphere
• B. Radius of the sphere
• C. Charge at the centre of the sphere✓
• D. Nature of charge

Explanation: The number of field lines depends only on the magnitude of the charge at the center of the sphere. The flux is proportional to the charge inside the surface.

Q165. When a 7000 N elevator moves from street level to the top of a building 300 m above the street level, what is the change in gravitational potential energy?

• A. 1.1 x 106 J
• B. 2.1 x 106 J✓
• C. 3.1 x 106 J
• D. 4.1 x 106 J
• E. 5.1 x 106 J

Explanation: Change in potential energy=Work done Change in potential energy=F.d =7000x300 =2100000 J 2.1x10^6 J

Q166. Angular velocity cannot be

• A. zero
• B. negative
• C. infinite
• D. linear
• E. C and d✓

Explanation: Angular velocity cannot be infinite. An infinite angular velocity would mean that the object is rotating infinitely fast, which is not physically possible. In reality, there are limits to how fast an object can rotate due to factors such as material strength and external forces.

Q167. One of the following is an Ohmic device:

• A. Filament bulb
• B. Semiconductor diode
• C. Transistor
• D. Copper wire✓

Explanation: Filament bulbs, thermistors and semiconductor diodes are non-ohmic materials while metals are ohmic devices or substances.

Q168. The number of electrons taken out from a body to produce 1 coulomb of charge will be:

• A. 6.25 X 1018✓
• B. 625 X 1018
• C. 6.023 X 1023
• D. None of these

Explanation: We can simply find the number of electrons taken out from a body to produce 1 coulomb of charge by using the following formula: Q = ne (*)where 'Q' is the charge, 'n' is the number of electrons, and 'e' is the electronic charge.Charge 'Q' = 1 Coulombe = 1.6 * 10⁻¹⁹ CThen, using (*), we get 1 = n * 1.6 * 10⁻¹⁹ 1/1.6 * 10⁻¹⁹ = n 6.25 * 10¹⁸ = number oof electronsHence, 6.25 * 10¹⁸ number of electrons are taken out from a body to produce 1 coulomb of charge.

Q169. A current of 4.4 amperes is following in a wire. How many electrons pass a given point in the wire in one second, if the charge on an electron is 1.6x10-19 Coulomb?

• A. 1.5 x 1019 electrons
• B. 2.75 x1019 electrons✓
• C. 3.25 x1019 electrons
• D. 2.75 x 1015 electrons
• E. 3.25 x 1017 electrons

Explanation: 4.4 Amperes means that 4.4 coulomb of charge passes through the conductor in one second. 1e contains 1.6x10-19 C , so 4.4 C will contain 4.4/1.6x10-19= 2.75x1019 electrons.

Q170. A positive point charge q1 creates an electric field of magnitude E1 at a spot located at a distance r1 from the charge. The charge is replaced by another positive point charge q2, which creates a field of magnitude E2 = E1 at a distance of r2 = 2r1. How is q1 related to q2?

• A. q2 = 4q1✓
• B. q2 = 2q1
• C. q2 = 0.5q1
• D. q2 = 0.25q1

Explanation: Formula for E: E = q / 4πɛr2 Since E1 = E2 q1 / 4πɛr12 = q2 / 4πɛr22 q1 / 4πɛr12 = q2 / 4πɛ (2 r1)2 ( r2 = 2r1) q1 / 4πɛr12 = q2 / 16 πɛ r12 q1 / 4 = q2 / 16 q2 = 4q1 Hence, A is the correct option

Q171. A force which is experienced in a magnetic field depends on:

• A. magnitude of charge
• B. speed of the moving charge V
• C. magnitude field of induction B
• D. all of these✓
• E. none of these

Explanation: Force on the charge in the magnetic field depends on the magnitude of the charge, the velocity of the charge, and the magnetic field of induction.

Q172. What is the flux density at a point 3 cm from the long straight wire, when there is a current of 25 A in a wire: (u0= 4𝜋 x10-7)

• A. 0.23x10-1 T
• B. 1.67x 10-4 T✓
• C. 2.99x10-6 T
• D. 3.63x10-8 T
• E. 999x10-7 T

Explanation: aMagnetic flux density is the number of lines of force that pass through a point on the specific surface. i.e., Magnetic fluxdensity = Φ/A we know, Φ = BA so, magnetic flux =BA/A = B ( magnetic field.) magnetic field at apoint of a long straight wire is given as , given, I = 25 A and r =3cm = 0.03m = 4π × 10^-7 × 25/2π ×(0.03) = (50/3) × 10^-5 T = 1.667 × 10^-4 T Hence, the magneticflux density is 1.667 × 10-4 T .

Q173. An ambulance siren emits a sound of frequency 1800 Hz. The speed of sound in air is 330m/s. If the ambulance moves toward a stationary observer at a constant speed of 50m/s. What is the frequency heard by the observer?

• A. (1800 x 290) / 330
• B. (1800 x 330) / 370
• C. (1800 x 330) / 280✓
• D. (1800 x 330) / 380

Explanation: The frequency heard by the observer will be (1800 x 330) / 280.

Q174. A neutron travels a distance of 12 m in a time interval of 3.6 x 10 - 4s. Assuming its speed was constant, find its kinetic energy. (take 1.7 x 10 - 27 kg is the mass of neutron)

• A. 3.14 eV
• B. 5.78 eV✓
• C. 7.71 eV
• D. 8.89 eV
• E. 9.96 eV

Explanation: K.E =½ mv2K.E =½ (1.7x10^-27) (12/3.6x10^-4)2K.E = 93x 10 ^-20 JConverting Joule into eV :K.E = 93x 10^ -20 / 1.6 x 10^-29K.E = 5.78 eVSo , option B is correct.As this question is theroretical options A, C, D and , E are incorrect.

Q175. Isotopes means addition of additional _ in same proton number.

• A. Protons
• B. Electron
• C. Neutrons✓
• D. All of them

Explanation: Option C is correct since the isotopes are defined as elements having the same proton number but different nucleon numbers. This difference in nucleon numbers is due to the neutrons. Option A is incorrect since proton numbers are the same in isotopes of the same element. Option B is incorrect since electrons remain the same in isotopes of the same elements. The proton number of unionized species is equal to its number of electrons. Option D is incorrect since it states all of them, which is not the case.

Q176. Two capacitors C1 ( 12 uf ) and C2 (24 uf) are in series connected across a 360 volts d.c. supply. Calculate the charges on C1 and C2 respectively.

• A. 2880 x 10-6 C , 2880 x 10-6✓
• B. 4770 x 10-6 C, 4770 x 10-6
• C. 5810 x 10-6 , 6610 x 10-6
• D. 7170 x 10-6 , 8140 x 10-6
• E. 9090 x 10-6 , 8880 x 10-6

Explanation: Charge throughout the circuit is the same so either the answer is A or B,as only these options have the same charge throughout. Q=CV Capacitance in series can be calculated as: 1/C=1/C1 + 1/C2 1/C=1/12 + 1/24 1/C=2+1/24 1/C=⅛ C=8 microfarads. ->Q=CV Q=(8x10^-6)(360) Q=2880x0^-6 C

Q177. If an object is undergoing an orbital motion around another object it is called

• A. Revolution✓
• B. Rotation
• C. Both of them
• D. None of them

Explanation: If an object is undergoing an orbital motion around another object it is called revolution. An orbit is a repeating and regular path where one object takes another object in space. An object with a larger mass moves front and it keeps moving forward. This orbital motion by an object towards another object is called revolution. One complete revolution around the sun by Earth takes a year. We all know that the sun is a huge massive object in our solar system. The remaining objects in the solar system are subjected to the gravitational pull of the sun.

Q178. If an A.C voltage rms value of 10 volt is applied as input of half wave rectifier, then the rms voltage value of D.C output will be

• A. 10V
• B. 10.3V
• C. 10.7V
• D. 9.3V✓

Explanation: Remember that The RMS value of DC output will always be less than a.c input 10 v. Here only D option is less than 10 v hence it is correct.

Q179. As the wavelength of light used increases, the distance between bright fringes in the interference pattern

• A. Increases✓
• B. Decreases
• C. Remains same
• D. None of these

Explanation: Option A is correct since the formula for fringe spacing is (L * lambda)/d where L is the distance between slits and screen,d is the slit separation. Therefore, the wavelength and distance between consecutive bright fringes are directly proportional. As the wavelength increases, the distance increases. Option B is incorrect since it shows that wavelength and fringe spacing are inversely proportional, which is not the case. Option C is incorrect since it shows that wavelength and fringe spacing are not related, which is not the case. Option D is incorrect since it states none of these, which is not the case.

Q180. When path difference between two waves are integral multiple of wavelength, the resultant effect is called _.

• A. Destructive interference
• B. Constructive interference✓
• C. Beats
• D. Diffraction

Explanation: Option B is correct because: Constructive interference occurs whenever the difference in paths from the two slits to a point on the screen equals an integral number of wavelengths (0, λ, 2λ,…). This path difference guarantees that crests from the two waves arrive simultaneously. Options A,C,D are incorrect because: These don’t fit the question

Q181. The spectrum of a star’s light is measured and the wavelength of one of the lines as the sodium’s line is found to be 589 nm. The same line has the wavelength of 497 nm when observed in the laboratory. This means the star is

• A. Moving away from the earth✓
• B. Moving towards the north
• C. Stationary
• D. Revolving around the planet

Explanation: When the wavelength of star was measured it resembled to the wavelength of sodium having wavelength 589 nm and when the sodium line was observed in the lab, its wavelength was calculated it came out to be 497nm . this means the wavelength had increased and it increases when star moves away

Q182. When the antinodes, in stationary waves, are passing through their equilibrium position, the energy is:

• A. Potential only
• B. Kinetic only✓
• C. A combination of both forms of energy
• D. There is no energy in stationary waves

Explanation: There is no energy transfer in stationary waves, but the energy of the antinodes keeps on changing from potential to kinetic energy. At the complete stretched position, the energy is wholly potential but as it passes through the equilibrium position, it is kinetic only.

Q183. If a wire having current 10A has a 3T magnetic field, what will be the magnetic field at a point from the wire at double the distance?

• A. Reduces by factor 2✓
• B. Becomes double
• C. Reduces by factor 4
• D. Becomes triple

Explanation: Any current-carrying wire is surrounded by the magnetic field which is B = µ0I/2πr. It can be seen from the above equation that the magnetic field is inversely proportional to the distance and directly proportional to the current. When the distance from the wire becomes double, the magnetic field will reduce by a factor of two, which is 1.5 T.

Q184. If momentum is increased by 20% then K.E. increases by :

• A. 0.44✓
• B. 0.55
• C. 0.66
• D. 0.77

Explanation: So, % change in KE =44% or 0.44.

Q185. The negative sign in "F = -k.x" indicates that _.

• A. F is directed opposite to x✓
• B. F is directed along x
• C. F is always equal to x
• D. none of these

Explanation: The negative sign in the equation indicates the opposite direction of the force, as the cos of 180° is -1.

Q186. The potential difference between the terminals of a battery in an open circuit is 2.2 V. When it is connected across a resistance of 5.0 Ω, the potential falls to 1.8 V. What is the internal resistance of the battery?

• A. 9.11 Ω
• B. 2.11 Ω
• C. 3.11 Ω
• D. 1.11 Ω✓
• E. 0.11 Ω

Explanation: The potential difference across the cell in an open circuit is the emf of the cell. Hence, emf E=2.2V When the circuit is closed, the potential difference across the cell is given by V=E−Ir And, I=E/R+r

Q187. A 10 nanofarad (10 x 10-9 F) parallel plate capacitor holds a charge of magnitude 50 µC on each plate.If the plates are separated by a distance of 0.885mm, what is the area of each plate?

• A. 1.0 m2✓
• B. 3.0 m2
• C. 5.5 m2
• D. 7.5 m2

Explanation: C = 10 x 10^-9 q=50 x10^-6 d= 0.885 × 10^-3 C = eA / d A= 10 X 10^-9 x 0.885 x10^-3 / 8.85 x 10^-12 A= 8.85 / 8.85 A = 1 m^2

Q188. A 1.75 m tall weight-lifter raises a weight of mass 50 kg to a height of 0.5 m above its head. How much work is being done by it? (g = 10 ms-2)

• A. 2125 J
• B. 2500 J
• C. 50 J
• D. 1125 J✓

Explanation: Work done = Force x parallel distance Force = mg : 50kg x 10 N/kg = 500 N Distance = 1.75m + 0.5m = 2.25 m W.D= 2.25m x 500 N = 1125 J

Q189. A body is having weight 20 N, when the elevator is descended with a = 0.1 ms-2, then the value of tension ‘T’ is:

• A. 196 N
• B. 19.8 N✓
• C. 1.98 N
• D. 2 N

Explanation: 𝑊 − 𝑇 = 𝑚𝑎 ⇒ 𝑚𝑔 − 𝑇 = 𝑚𝑎 ⇒ 𝑇 = 𝑚(𝑔 − 𝑎) To calculate the mass we need to divide W by g therefore, m = 20/9.81 = 2.04 kg. Inputting value of mass, g = 9.81 and a = 0.1 ms -2 we get the answer.

Q190. A block hangs freely from the end of a spring. A boy then slowly pushes the block upwards so that the spring becomes strain free. The gain in gravitational potential energy of the block during this process is equal to:

• A. work done by the boy against the gravitational force acting on the block
• B. loss of energy stored in the spring minus the work done by the tension in the spring
• C. work done on the block by the boy plus the loss of energy stored in the spring✓
• D. work done on the block by the boy minus the work done by the tension in the spring

Explanation: Let xo be the initial extension of the spring. Then the initial energy stored in the spring is: ½kxo2 The gain in gravitational potential energy: mgh = mgxo The work done increases the gravitational potential energy and decreases the spring’s potential energy. The total energy gained = gain in the gravitational potential energy - loss in spring’s potential energy. Therefore, work done by the boy (wb) = gain in the gravitational potential energy - loss in spring’s potential From here you can see that the gain in the gravitational potential energy of the block = work done by the boy + loss in the spring’s potential energy. Therefore, option C is the correct one.

Q191. Calculate the final kinetic energy when a shop keeper pushes a fruit crate, initially at rest, towards another shopkeeper by exerting a constant horizontal force F of magnitude 5N through a distance of 1 meter.

• A. 2 J
• B. 3 J
• C. 5 J✓
• D. 7 J
• E. 9 J

Explanation: Given: Force= 5N Distance=1m Work done= energy converted Fd=1/2mv² 5×1=energy converted Energy=5J

Q192. A particle is travelling along a straight line OX. The distance x (in metre) of the particle from O at a time ′t′ is given by x = 37 +27t - t3 , where 't' is time in seconds. The distance of the particle from O, when it comes to rest is:

• A. 81 m
• B. 91 m✓
• C. 101 m
• D. 111 m

Explanation: Correct option is 91 m. (The solution involves calculus, which most pre-medical students will not be familiar with. This type of question is highly unlikely to be asked.)

Q193. What happens when charge is placed on a soap bubble?

• A. It collapse
• B. Its radius increases.✓
• C. Its radius decreases.
• D. None of the above.

Explanation: When some charge is placed on a soap bubble then the radius of the bubble will increase. Firstly, the charge will be distributed uniformly on the surface of a bubble. Secondly, the bubble will expand because the charged particles uniformly distributed on it cause them to repel each other due to the electrostatic force.

Q194. Look at this series: 7, 10,8, 11, 9, 12. Which number do you think will be next?

• A. 10✓
• B. 12
• C. 13
• D. 7

Explanation: Option A is correct since this is a 3 and 2 series. We are adding 3 to 7 so it becomes 10. Then we subtract 2 from 10 so that it becomes 8. Then we add 3 to 8 so it becomes 11. Then we subtract 2 from 11 so it becomes 9. We add 3 to 9 so it becomes 12. Finally, when we subtract 2 from 12, we get 10. Option B is incorrect since it does not give the right answer. Option C is incorrect since it does not give the right answer. Option D is incorrect since it does not give the right answer.

Q195. Number series Look at this series 14, 28, 20, 40, 32, 64. What number should come next?

• A. 52
• B. 56✓
• C. 96
• D. 128

Explanation: This is an alternating multiplication and subtracting series: First, multiply by 2 and then subtract 8. Rule = (1st no.) (1st× 2 = 2nd no.) (2nd - 8 = 3rd no.) (3rd × 2 = 4th no.).... Now (14) (14 × 2 = 28) (28 - 8 = 20) (20 × 2 = 40) (40 - 8 = 32) (32 × 2 = 64) (64 - 8 = 56). So the answer is b = 56.

Q196. Choose the odd one out:

• A. Eagle
• B. Cloud
• C. Squirrel✓
• D. Plane

Explanation: All Options excluding C refers to animals and objects that are involved in flying. Squirrel is the only option that is present on the ground.

Q197. Series completion (Numbers/Letters) Look at this series: 80, 10, 70, 15, 60, ... What number should come next?

• A. 20✓
• B. 25
• C. 30
• D. 50

Explanation: This is an alternating addition and subtraction series. In the first pattern, 10 is subtracted from each number to arrive at the next.In the second, 5 is added to each number to arrive at the next. First pattern (80) (80 - 10 = 70) (70 - 10 = 60) (60 - 10 = 50) Second pattern (10) (10 + 5 = 15) (15 + 5 = 20)So the answer is a = 20.

Q198. Statements: All film stars are playback singers. All film directors are film stars. Conclusions: I. All film directors are playback singers. II. Some film stars are film directors. Which of the following is true?

• A. Only conclusion II follows
• B. Either I or II follows
• C. Neither I nor II follows
• D. Both I and II follows✓

Explanation: Since both the premises are universal and affirmative, the conclusion must be universal affirmative and should not contain the middle term. So, I follow. II is the converse of the second premise and so it also holds.

Q199. Statement: A large number of people living in the low-lying areas has been evacuated during the last few days to safer places. The government has rushed in relief supplies to the people living in the affected areas.

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

Explanation: Evacuation of people from low-lying areas and providing relief measures is indicating the fact that some natural calamity had occurred like flood or so. Thus, both are the effects of that natural calamity.