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 trick to solving these types of questions is to read the question a few times in your head. Here the word “does” is redundant and breaks the flow of the sentence.It should be “...how much the car costs…”

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: When talking about an amount of money, Rupees requires a singular verb; however, when referring to Rupees generically, use a plural verb. Twenty Rupees buys a pizza. Rupees are worth more in some countries than others.

Q6. Choose the correct option.

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

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

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: "Students’" is the correct possessive form of "students," showing that the results belong to multiple students. The apostrophe after "s" correctly indicates plural possession.

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: Complex sentences are those with one independent and at least one dependent clause hence this sentence is complex. Hence option A is correct.

Q11. Identify which part of the statement contains the error: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: The sentence is in the past so "would" must be used instead of "will". Also, the sentence is for a hypothetical situation that could have happened in the past, would is the past form of will and can be used to express the conditional tense or hypothetical situations.

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: the verb "differ" is the correct choice to complete the sentence and describe how the two machines have considerable differences between them.

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. Mona's dog Sam, who assist her physical needs and daily activities✓
• 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: Based on the information provided in the passage, the dog that is most likely a service dog is Sam. Here's why:The passage explicitly states that Sam is a service dog trained to assist someone with physical problems. Mona has difficulties with balance, walking, and performing daily activities, and Sam helps her with these tasks. Sam performs various tasks that are typical of a service dog:He supports Mona by letting her lean on him while walking.He pulls her wheelchair.He turns lights on and off.He picks up items when Mona drops them.He pulls off Mona’s socks at night.Sam also assists Mona with her school tasks, such as carrying her books, putting completed assignments in homework trays, and throwing away trash in the lunchroom.

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.As used in paragraph 1, which word means the opposite of complicated?

• A. Difficult
• B. Simple✓
• C. Easy
• D. Manageable

Explanation: In paragraph 1 of the passage, the word that means the opposite of "complicated" is simple ; basic.Here's the reasoning:The passage states, "Making the perfect pizza can be complicated, but there are lots of ways for you to make a more basic version at home."Here, "complicated" suggests something intricate or complex, implying that making a pizza from scratch can be challenging.

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: The correct answer is the decline phase. During this phase, the conditions are no longer favorable for bacterial growth due to the depletion of nutrients and accumulation of waste products, resulting in a death rate that exceeds the growth rate. In contrast, the stationary phase is characterized by an equilibrium between growth and death rates. The lag phase involves adaptation to new conditions with minimal cell division, while the log phase is marked by rapid and exponential bacterial growth.

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: Erythroblastosis fetalis occurs when an Rh-negative mother carries an Rh-positive fetus. The mother's immune system may recognize the Rh-positive red blood cells of the fetus as foreign and produce antibodies against them, leading to hemolysis. This condition typically arises during a second pregnancy, after the mother has been sensitized by a previous Rh-positive pregnancy. Options A, C, and D are incorrect because they describe scenarios where there is no Rh incompatibility. Option E is also incorrect as it incorrectly suggests that all scenarios could result in erythroblastosis fetalis, which is not the case.

Q25. An example of a bacteria requiring low concentration of oxygen is?

• A. Spirochete
• B. Escherichia coli (E. coli)
• C. Pseudomonas
• D. Campylobacter✓

Explanation: Option D: Campylobacter is the correct answer as it is a microaerophilic bacterium, requiring low levels of oxygen to survive and grow. This characteristic distinguishes it from the other options. Option A: Spirochetes can survive in a range of oxygen levels and are not exclusively microaerophilic. Option B: E. coli is a facultative anaerobe, adaptable to both oxygen-rich and oxygen-poor environments. Option C: Pseudomonas are versatile in their oxygen requirements and are not limited to low-oxygen conditions.

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 is essential for the synthesis of chlorophyll, the pigment responsible for capturing light energy in photosynthesis. It forms the central atom in the chlorophyll molecule, which is crucial for plants to convert sunlight into chemical energy. Magnesium is not directly involved in protein synthesis, which primarily requires nitrogen, or in the synthesis of glucose, although it does play a supportive role in glucose metabolism.

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: Looking at the diagram, it is apparent that increasing glucose concentration in the surrounding tube will decrease the difference in the concentration of glucose between the surrounding liquid and inside the visking tubing. As there is less concentration gradient, the net diffusion of water would decrease so statement I is incorrect. The time to reach equilibrium would decrease as there is less difference in concentration of glucose, so statement II is correct. As the concentration gradient is less, less net movement of water would be needed to reach equilibrium, so volume would also change less, hence statement III is correct. There is no movement of glucose molecules, so statement IV is incorrect.

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: Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the alveoli and the capillaries in the lungs. Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs.

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

• A. 5
• B. 6✓
• C. 8
• D. 4

Explanation: Citrate, the first compound formed in the Krebs cycle (also known as the citric acid cycle or tricarboxylic acid cycle), has six carbon atoms. Its chemical formula is often written as C6H8O7, indicating six carbon atoms, eight hydrogen atoms, and seven oxygen atoms. The Krebs cycle is a series of chemical reactions that takes place in the mitochondria of cells, and citrate is a key intermediate in this cycle.

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

• A. 4X✓
• B. 10X
• C. 40X
• D. 400X

Explanation: The total magnification of a microscope is the product of the magnifications of the eyepiece and the objective lens. In this case, you need to find the magnification power of the objective lens. Given that the eyepiece magnification is 10X and the total magnification is 40X, you calculate the objective lens magnification as follows: 40X / 10X = 4X.Other options are incorrect because they either confuse the eyepiece magnification with the objective lens magnification or misunderstand the relationship between total magnification and the magnifications of the individual components of the microscope.

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: The ability to taste the substance is dominant (T) and the inability to taste is recessive (t). If Pasha and Hina are both heterozygous (Tt), their children can have the following genotypes: TT → tasterTt → taster tT → taster (same as Tt)tt → non-tasterThe genotype ratio is 1 TT : 2 Tt : 1 tt, so the phenotype ratio is 3 tasters : 1 non-taster.Percentage of non-tasters: 25%.Conclusion: 25% of Pasha and Hina’s children are expected to be non-tasters.

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: Color blindness is a sex-linked genetic disorder that is carried on the X chromosome. Females have two X chromosomes, while males have one X and one Y chromosome. In this scenario, the mother is color blind, which means she has one X chromosome with the color blindness allele. The father is normal, which means he has one X chromosome without the color blindness allele and one Y chromosome. Therefore, the father cannot pass on the color blindness allele to his son, but the mother can pass on the color blindness allele to her son. Since the son only has one X chromosome, he will express the color blindness phenotype if he inherits the color blindness allele from his mother. Therefore, the risk of a color blind baby boy in this family is 100%.

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: Historical Perspectives Centennial: Koch's Discovery of the Tubercle Bacillus. On March 24, 1882, Robert Koch announced to the Berlin Physiological Society that he had discovered the cause of tuberculosis. Three weeks later, on April 10, he published an article entitled "The Etiology of Tuberculosis".

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 the 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 they need 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.

Q39. 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: Hybrid black Guinea pigs have the genotype Bb, where B (black) is dominant and b (white) is recessive. When two Bb individuals are crossed, the Punnett square results in the following combinations:BB (Black) – 1/4 (25%)Bb (Black) – 1/2 (50%)bb (White) – 1/4 (25%)Thus, out of four offspring, three will be black (BB or Bb), and one will be white (bb).

Q40. 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.

Q41. In a bacterial cell, plasma membrane with all things present within it is called:

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

Explanation: The correct answer is 'Protoplasm'. In the context of bacteria, the protoplasm is the term used to describe all the living contents within the plasma membrane, which includes both the cytoplasm and the genetic material. The 'Cytoplasmic matrix' refers only to the fluid part of the cytoplasm, excluding organelles and other inclusions. 'Cytoplasm' typically refers to the contents within the cell membrane excluding the nucleus, which is not wholly applicable to prokaryotes as they lack a defined nucleus. 'Cell Structure' is a non-specific term that does not precisely address the composition within the plasma membrane.

Q42. Which of the following are present in the internal organs, like the stomach, intestine, etc.?

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

Explanation: Smooth muscles are present in the walls of internal organs such as the stomach, intestine, bladder, etc. They are non-striated muscles that are not under voluntary control. Cardiac muscle, represented by option B, is found only in the heart and is also striated like skeletal muscle. Skeletal muscles, represented by option C, are attached to the bones and are under voluntary control. Therefore, the correct answer is option A.

Q43. Which one of the following is a “myogenic” type of muscle?

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

Explanation: The term 'myogenic' refers to muscle contractions that originate from the muscle tissue itself without external stimuli from the nervous system. Cardiac muscles are 'myogenic' because they can initiate contractions autonomously due to the intrinsic pacemaker cells of the heart. This distinguishes them from skeletal muscles, which are 'neurogenic,' as they require neural input to contract. Although some smooth muscle types are 'myogenic,' the question specifies a singular type of 'myogenic' muscle, making cardiac muscle the most precise answer.

Q44. 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

Q45. 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.

Q46. 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: To solve this, consider the genetics involved: The man is color-blind (XcY), and the woman, who has normal vision but a color-blind father, is a carrier (X+Xc). When they have a daughter, the possible combinations of X chromosomes are: X+Xc (carrier, normal vision) and XcXc (color-blind). Thus, there is a 50% chance that their daughter will be color-blind. Options A and D are incorrect as they underestimate and overestimate the probability, respectively. Option B is incorrect because it fails to account for both sources of the recessive allele.

Q47. Synaptic vesicles discharge which neurotransmitter at the neuromuscular junction?

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

Explanation: Acetylcholine is the neurotransmitter 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.

Q48. 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 ATPase complex, also known as ATP synthase, uses the energy from the flow of protons across the mitochondrial membrane to synthesize ATP from ADP and inorganic phosphate (Pi). This process requires the movement of three protons for the production of one ATP molecule. This is a key step in oxidative phosphorylation during cellular respiration. The other options, such as sugar molecules, NADP, and NADPH, are not directly synthesized through the ATPase complex. Instead, they are involved in other metabolic pathways.

Q49. A bacterial cell envelope of mollicutes does not include?

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

Explanation: Mollicutes is a class of bacteria which does not contain cell wall in its cell envelope.While in most of the bacteria the cell envelope comprises of cell membrane and cell wall, mollicutes lack a peptidoglycan cell wall.

Q50. 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.

Q51. When a color-blind male marries a normal female, what will be the chances of colorblindness in his grandsons, if his daughter is married to a normal male?

• A. 16%
• B. 25%
• C. 50%✓
• D. 100%

Explanation: The correct answer is 50%. When a color-blind male marries a normal female, all their daughters will be carriers of the color-blind gene because they inherit the X chromosome carrying the gene from their father. When one of these carrier daughters marries a normal male, each son has a 50% chance of inheriting the X chromosome carrying the color-blind gene, resulting in a 50% chance of being color-blind. The other options are incorrect because they do not correctly apply the rules of X-linked recessive inheritance.

Q52. 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, as they are more concentrated inside than outside. This outflow of potassium ions helps return the membrane potential to a negative value, restoring the resting membrane potential.

Q53. 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.

Q54. 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.

Q55. 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.

Q56. 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.

Q57. 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.

Q58. 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 tail bone 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.

Q59. 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.

Q60. 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.

Q61. Choose a correct statement among the following:

• A. Spinal reflexes have 4 elements
• B. Lower motor neurons have their cell bodies in the anterior column of grey matter✓
• C. Grey matter that lies transversely is the lateral commissure
• D. The 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 have 3 elements. C is incorrect as the area of grey matter that lies transversely is the transverse commissure. D is incorrect as the spinal cord is divided into 4 equal parts.

Q62. 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: Enzymes for light-dependent reactions are associated with the thylakoid membranes of the chloroplasts since Light dependent reaction occurs here.

Q63. 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).

Q64. 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.

Q65. 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.

Q66. Lipids store double amount of energy as compared to carbohydrates because of:

• A. High proportion of oxygen
• B. Low proportion of carbon
• C. Lower proportion of C-H bonds
• D. High proportion of C-H bonds✓

Explanation: Option D is correct. Lipids store more energy than carbohydrates primarily because they have a higher proportion of carbon-hydrogen (C-H) bonds. These bonds are strong and release a large amount of energy when broken, which accounts for the higher energy content of lipids. In contrast, carbohydrates have more oxygen-hydrogen bonds, which release less energy. Option A is incorrect because lipids have a lower proportion of oxygen, not higher. Option B is incorrect because lipids have a high proportion of carbon. Option C is incorrect as lipids have more C-H bonds, not fewer.

Q67. 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: Among the given options, the correct structure that surrounds the primary oocyte in mammals is the Zona Pellucida.Zona Pellucida: The Zona Pellucida is a thick glycoprotein-rich layer that surrounds the mammalian oocyte. It is formed by the secretions of the oocyte itself and the surrounding follicle cells. The Zona Pellucida plays a crucial role in fertilization by mediating the interaction between sperm and oocyte and preventing polyspermy (fertilization by more than one sperm).Zona Vasculosa: The term "Zona Vasculosa" typically refers to the vascular zone found in the embryonic chick blastoderm, which is different from the structures surrounding the primary oocyte in mammals. It is responsible for supplying nutrients and oxygen to the developing embryo.Zona Radiata: The term "Zona Radiata" is often used to describe the outermost layer of the mammalian ovarian follicle. It consists of several layers of follicular cells that surround the Zona Pellucida. The Zona Radiata provides structural support and aids in the maturation and release of the oocyte during ovulation.In summary, the correct structure that surrounds the primary oocyte in mammals is the Zona Pellucida. The Zona Vasculosa refers to a vascular zone in the embryonic chick blastoderm, and the Zona Radiata describes the outermost layer of the ovarian follicle in mammals.

Q68. Coagulated protein is:

• A. Insoluble
• B. Non-folded
• C. Non-functional
• D. All of the above✓

Explanation: When proteins are coagulated, they undergo a structural change that results in them becoming insoluble, non-folded, and non-functional. This process alters their physical state and biological activity, rendering them unable to perform their original functions. Option D is correct because it captures all these key characteristics of coagulated proteins. Options A, B, and C each describe only one aspect of coagulated proteins, making them incomplete choices.

Q69. For every 3 molecules of carbon dioxide in Calvin cycle how much G3P is produced?

• A. 6✓
• B. 5
• C. 3
• D. 8

Explanation: In the Calvin cycle, 3 molecules of carbon dioxide are fixed by an enzyme called RuBisCO, resulting in 6 molecules of G3P. These are the initial products of carbon fixation. Out of these 6 G3P molecules, 5 are used to regenerate RuBP, the CO2 acceptor molecule, and 1 is available for synthesis of glucose and other carbohydrates. Therefore, while the Calvin cycle produces 6 G3P molecules for every 3 CO2 molecules, only one contributes directly to biosynthesis outside the cycle. The incorrect options either underestimate or overestimate the number of G3P molecules produced.

Q70. 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.

Q71. Which of the following is a chemical link between catabolism and anabolism?

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

Explanation: ATP, or adenosine triphosphate, is the central molecule in cellular energy transfer, acting as the primary energy carrier. During catabolic processes, energy is released from the breakdown of molecules and captured in the form of ATP. This energy is then used in anabolic processes to synthesize complex molecules. Thus, ATP serves as the chemical link between catabolism and anabolism. Although AMP and ADP are part of the energy cycle, they do not directly serve as the main link between these processes. The option 'All of these' is incorrect because only ATP fulfills this specific role.

Q72. 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)

Q73. The number of vertebrae in a horse's neck is:

• A. 5
• B. 6
• C. 7✓
• D. 10

Explanation: The horse has 7 cervical vertebrae, with the 1st (C1) and 2nd (C2) cervical vertebrae being morphologically extremely modified for their particular functions.

Q74. What will happen if ligaments are torn ?

• A. Bones will move more freely at the joint without pain.
• B. Bone movement becomes unstable and painful.✓
• C. Bones will become dislocated from each other.
• D. Joint will become immobile.

Explanation: Ligaments are essential for connecting bones at synovial joints, providing stability and allowing controlled movement. When ligaments are torn, the joint becomes unstable and movement is both painful and restricted, making Option B the correct choice. Option A is incorrect because the instability caused by torn ligaments results in pain, not free movement. Option C incorrectly suggests that bones will dislocate, which is not directly caused by torn ligaments, though instability increases the risk. Option D is incorrect as torn ligaments lead to instability and pain, but not complete immobility of the joint.

Q75. Secondary oocyte is ovulated from:

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

Explanation: The secondary oocyte is ovulated from a structure known as the Graafian follicle, also referred to as the mature or tertiary follicle. The process starts with the development of a primordial follicle, which goes through several stages of development, including the primary follicle, secondary follicle, and then the mature Graafian follicle. The Graafian follicle is the final stage of follicular development before ovulation. Upon maturation, the Graafian follicle releases the secondary oocyte during ovulation. This event marks the rupture of the follicle, and the secondary oocyte is released into the fallopian tube. From there, it can be fertilized by sperm if present, leading to the formation of a zygote and, ultimately, pregnancy. If fertilization does not occur, the remaining components of the Graafian follicle undergo degeneration.

Q76. 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.

Q77. 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, to stimulate a muscle contraction.

Q78. The diagram shows a molecule. Which substance might include the above molecule?

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

Explanation: The given molecule is identified as an amino acid due to the presence of an alpha carbon bonded to an amino group, a carboxyl group, and a side chain. The side chain in the molecule is a methyl group (-CH3), which is specific to alanine, making option D the correct answer.Option A, Cellulose, is a carbohydrate, not an amino acid, as it consists of glucose units. Option B, Serine, is an amino acid but has a hydroxymethyl group instead of a methyl group. Option C, Glucose, is a simple sugar and lacks the functional groups characteristic of amino acids.

Q79. 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 viruses that infect bacteria. They are primarily composed of DNA and protein. The DNA serves as the genetic material, and the protein coat protects the DNA and facilitates the infection of bacterial cells. While some bacteriophages have RNA instead of DNA, these are less common. Options such as RNA only, protein only, or DNA only do not accurately describe the typical structure of a bacteriophage, which relies on both genetic material and a protein coat for function and survival.

Q80. 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.

Q81. 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 immovable joints connected by tough fibrous tissue, such as sutures in the skull. They do not allow movement, making them distinct from synovial and cartilaginous joints. Synovial joints permit a wide range of motion due to their fluid-filled cavities, and cartilaginous joints allow limited movement due to their cartilage connections. Therefore, the correct answer is 'Fibrous joint'.

Q82. 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.

Q83. 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 filum terminal begins at the tip of the conus medullaris and extends to the pelvis.

Q84. 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.

Q85. 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.

Q86. 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.

Q87. The electrolysis of acetate solution produces ethane according to the 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: Q V/FFrom the chemical equation, 2 moles of electrons produce 3 moles of gases (C2H6 + 2CO2)Now, Q = ItAs given, I = 0.5At = 96.45 min = 96.45 x 60 = 5787 sQ = 0.5 x 5787= 2893.5However, the system is only 80% efficient or has an efficiency of 0.8. So,Actual Q = 0.8 x Q= 0.8 x 2893.5= 2314.8 CNow, according to the formulaN = actual Q/F (where F = Faraday’s constant = 96485 C/mol, and n = no. of electrons)So, n = 2314.8 / 96485= 0.024As 3 moles of gases are produced, then 3n = 3 x 0.024= 0.036Now, according to the gas equationPV = nRTOr V = nRT/PPut n = 0.036, R = 0.0821, T= 300 K, P = 0.97 atmV = [0.036*0.0821*300]/0.97= 0.91LHence, option D is the correct option.

Q88. 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.

Q89. 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.

Q90. 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 bond lengths of ethane, ethene and ethyne are 154pm, 133pm and 120pm respectively. Hence, ethyne has shortest bond length.

Q91. 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: Methyl Alcohol, also known as methanol, is a colorless, volatile, and thin liquid with a specific gravity of 0.796 at 15°C. This makes Option A the correct choice. Methyl Alcohol is primarily used as an industrial solvent and antifreeze, and is not suitable for consumption or use in perfumes due to its toxicity. Options B and C describe Ethanol, which is used in thermometers and beverages. Option D describes esters, often used in perfumes. Option E describes Phenol, which is used as an antiseptic and disinfectant.

Q92. 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.

Q93. 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: Ethers are generally volatile liquids with low boiling points because they cannot form strong intermolecular hydrogen bonds. They are also highly flammable. Although they do not hydrogen-bond with themselves, they can form weak hydrogen bonds with water. However, the statement that an ether is poisonous and used as a disinfectant in hospitals is incorrect—this property refers to phenol, not ethers. Therefore, option D is not a physical property of ethers.

Q94. 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.

Q95. A compound has an empirical formula, C2H2O. If the experimental molecular weight is found to be in the range of 160–170, the molecular formula of this compound is: (Atomic weight: C = 12.1, H = 1, O = 16).

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

Explanation: The molecular mass of the empirical formula is 2(12.1) + 2(1) + 16 = 42.2Now, we need to find 'n' Experimental molecular weight = 165 (average of the given range of 160–170)We can find n byn= (experimental molecular weight) / (empirical formula mass) = 165/42.2 = 3.9 Hence, ‘n’ is approximately 4 Now, 4C2* 4H2* O4 = C8H8O4 Hence, option C is the correct option.

Q96. 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.

Q97. 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.

Q98. 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: PV=nRT V=nRT/P If temperature is halved and pressure is doubled then V=n x R x 0.5T/2P = V=¼(nRT/P) Hence, volume is decreased four times.

Q99. A sample of gas weighs 1.25 g, at 28 C occupying a volume of 2.50 x 102 ml and its pressure is 715 torr. What is the molar mass in grams?

• A. 131.1 g/mol✓
• B. 1.311 g/mol
• C. 1.212 g/mol
• D. 122.1 g/mol

Explanation: Mass of gas = 1.25 gThe volume of gas = 2.50 x 102 ml= 0.25 LPressure of gas = 715 torrThe temperature of gas = Using the ideal gas law,PV=nRTPV=(m/M)RTM=mRT/PVwhere,M = Molar mass of gasW = Mass of gasR = gas constantT = temperature of the gasP = Pressure of gasV = Volume of gasNow put all the given values in the above formula, and we get the value of the molar mass of gas.M=(1.25)(62.364)(1.25)/(715)(0.25)M=131.1g/mol

Q100. 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.

Q101. 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.

Q102. Legumine & collagen protein are present in which type of body tissues?

• A. Cardiac
• B. Epithelial
• C. Connective✓
• D. Epidermis

Explanation: Collagen is the principal protein of the skin, tendons, ligaments, cartilage, bone, and connective tissue. It is present in large quantities in connective tissue and provides bone, tendons, and ligaments with tensile strength and skin with elasticity.A) Cardiac, B) Epithelial, and D) Epidermis are not the correct answers as cardiac tissue is found in the heart and is made up of cardiac muscle cells, epithelial tissues cover the surfaces of organs, and the epidermis is the outermost layer of the skin.

Q103. 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.

Q104. When the number of moles of reactants and products are equal in reversible reaction which parameter would not affect at fusion equilibrium?

• A. Temperature
• B. Pressure✓
• C. None of them
• D. Catalyst

Explanation: When the number of moles of reactants and products is equal, changes in pressure do not affect the equilibrium position because there is no net change in volume. Temperature can affect equilibrium because it can alter the balance of endothermic and exothermic reactions. A Catalyst speeds up the rate of a reaction but does not change the equilibrium position.

Q105. For which of the following order of the reaction, rate of reaction is directly 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 correct answer is a second-order reaction (option B), where the rate of reaction is proportional to the square of the concentration of the reactant. This means that as the concentration increases, the rate increases even more significantly.Option A (1st order) is incorrect because, while the rate is proportional to the concentration, it is a linear relationship (not directly proportional in the same manner as second order). Option C (negative order) is not applicable, as it does not exist in conventional reaction kinetics. Lastly, option D (zero order) is incorrect as the rate is constant and does not depend on concentration at all.

Q106. 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: The correct answer is Option A: 1 min. The half-life of a first-order reaction is calculated using the formula t1/2 = 0.693 / k. By substituting the given rate constant k value of 0.693min^-1, we find t1/2 = 0.693 / 0.693 = 1 min. This demonstrates the direct relationship between the rate constant and the half-life in first-order reactions. The other options incorrectly interpret the relationship between the rate constant and half-life, leading to incorrect results.

Q107. 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: The Le Chatelier's principle states that when a system in equilibrium is subjected to a change in conditions, the system will adjust itself in a way that minimizes the effect of that change. In the context of reversible chemical reactions, several factors can influence the equilibrium position, and hence the direction in which the reaction will proceed. Here are some factors and how they affect reversible chemical reactions according to Le Chatelier's principle:1. Concentration: If the concentration of a reactant or product is changed, the system will shift to minimize the effect of that change. An increase in the concentration of a reactant will cause the reaction to shift in the forward direction to consume the excess reactant. Conversely, an increase in the concentration of a product will drive the reaction in the reverse direction to consume the excess product.2. Pressure: For gaseous reactions, changes in pressure can affect the equilibrium position. According to Le Chatelier's principle, an increase in pressure will shift the equilibrium towards the side with fewer moles of gas to reduce the pressure. Conversely, a decrease in pressure will shift the equilibrium towards the side with more moles of gas.3. Temperature: Altering the temperature can have a significant impact on reversible reactions. In an exothermic reaction (heat-releasing), increasing the temperature will favor the reverse reaction as it consumes heat. In contrast, decreasing the temperature will favor the forward reaction. For an endothermic reaction (heat-absorbing), the opposite holds true.4. Catalysts: Catalysts increase the rate of a chemical reaction by providing an alternative reaction pathway with lower activation energy. They do not affect the equilibrium position or the composition of the equilibrium mixture. However, by speeding up the attainment of equilibrium, they can influence the time it takes to reach equilibrium.5. Inert gases: Inert gases do not participate in the reaction. Their introduction at constant volume does not affect the equilibrium position. However, if the reaction involves gases, increasing the total pressure by introducing an inert gas will cause no effect on the equilibrium composition.These factors demonstrate how changes in concentration, pressure, temperature, and the presence of catalysts or inert gases can influence the direction in which a reversible chemical reaction proceeds according to Le Chatelier's principle.Le-Chatelier studied the effects of temperature, pressure and concentration on equilibria and explained the Le-Chatelier's principle which states that: If stress is applied on any system at equilibrium, the system acts in a way to nullify, to the farthest extent, the effect of that stress. This stress may be in the form of a change in pressure, temperature or concentration. Increase in pressure shifts the equilibrium towards the side which has fewer moles. Increase in temperature shifts the equilibrium towards the product side for endothermic reactions and towards the reactants side for endothermic reactions. Increase in concentration of reactants shifts the equilibrium towards the product side while increase in products shifts it towards reactant side. Therefore, option D is correct as it includes all of these factors.

Q108. According to Pauli's exclusion principle, both electrons in a degenerate orbital:

• A. Same spin
• B. cannot have 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.

Q109. 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.

Q110. 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.

Q111. 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.

Q112. Transfer of heat from cold to hot place in refrigerator mechanism 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: In this case:Heat is being transferred from hot surroundings to the cold interior of a refrigerator, which is against the natural direction of heat flow.This process requires work, done by the refrigerator's compressor, which uses electrical energy to move heat from a colder region to a hotter one.According to the Second Law of Thermodynamics, heat cannot flow from cold to hot spontaneously.It can only happen when external energy is supplied — so the process is non-spontaneous.

Q113. 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. As here, it is less than 1.7, nature is covalent.

Q114. 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.

Q115. 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: Rate Law: Rate = k The unit of the rate constant (k) is typically expressed as concentration unit per time. The unit of the rate of reaction (Rate) is also in concentration unit per time. Therefore, in a zero-order reaction, the unit of the rate constant is the same as the unit of the rate of reaction.

Q116. 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.

Q117. 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

Q118. 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.

Q119. 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.

Q120. 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.

Q121. Which one is the correct geometry of acetal?

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

Explanation: The correct geometry of acetal is C) Tetrahedral. Acetal has a tetrahedral arrangement of atoms around the central carbon atom, with two hydrogen atoms and two alkyl or aryl groups attached to it.

Q122. In the addition of sodium bisulfite to carbonyl system, which of the following is nucleophile?

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

Explanation: In the addition of sodium bisulfite (NaHSO3) to a carbonyl system, the nucleophile is the sulfite ion (SO32-). Sodium bisulfite reacts with carbonyl compounds, such as aldehydes and ketones, in a nucleophilic addition reaction. The sulfur atom in the sulfite ion (SO32-) bears a partial negative charge, making it a nucleophile. The nucleophilic sulfur attacks the electrophilic carbon of the carbonyl group, forming an addition product known as a bisulfite adduct. The reaction can be represented as follows: R-C=O + NaHSO3 → R-C(HSO3)O-Na+ (Bisulfite adduct) In this reaction, the sulfite ion (SO32-) acts as the nucleophile and adds to the carbonyl carbon, resulting in the formation of the bisulfite adduct. Therefore, option b is correct.

Q123. 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.

Q124. 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.

Q125. 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.

Q126. In a galvanic cell, copper compartment get net negative charge due to arrival of:

• A. Free charge from zinc sulphate solution
• B. Electrons✓
• C. Protons
• D. Zinc ions

Explanation: In a galvanic cell, the copper compartment becomes negatively charged due to the arrival of electrons. Electrons flow from the zinc anode to the copper cathode through the external circuit, causing the cathode to gain a net negative charge. Option B is correct because it accurately describes this process. Option A is incorrect because free charges from the zinc sulphate solution do not directly move to the copper compartment. Option C is incorrect because protons remain in the electrolyte and do not contribute to the charge of the copper compartment. Option D is also incorrect because zinc ions move into the solution from the anode but do not enter the copper compartment.

Q127. 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: These all options are the physical properties of Ethyne:

Q128. 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.

Q129. 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

Explanation: Correct option is C. Alkaline earth metals have smaller atomic sizes as compared to alkali metals so electrons of outermost shells of alkaline earth metals are held tightly. As the nuclear charge increases it requires more energy to remove electrons(Ionization energy) hence ionization energy will be increased. The first ionization energies of alkaline earth metals are higher than those of the alkali metals. This is because of the increase in the nuclear charge of the alkaline earth metal.

Q130. For the purification, impure copper is made the:

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

Explanation: In the electrolysis process for purifying copper, the impure copper is used as the anode. When an electric current is passed through the solution, copper atoms from the anode dissolve into the solution as copper ions (Cu2+) and migrate to the cathode, where they gain electrons and deposit as pure copper. The impurities in the anode either fall off or remain in the solution, depending on their solubility. The cathode, made of pure copper, is the site of copper deposition.Option A is incorrect because the cathode is not made of impure copper; it serves as the site for deposition of pure copper. Option C is incorrect as the solution is part of the electrolysis setup but does not refer to the impure copper. Option D is incorrect as it suggests both electrodes are made of impure copper, which is not the case.

Q131. The number of electrons present in n = 2, l = 1 and m = -1, 0, +1 are:

• A. 6✓
• B. 2
• C. 8
• D. 10
• E. 18

Explanation: n is the principal quantum number and indicates the number of shells. n = 2 indicates that the second shell is being discussed. l is the azimuthal quantum number and indicates the number of subshells. l = 0 means s subshell, l = 1 means p subshell, and so on. m is the magnetic quantum number and indicates the orientation of orbitals in the subshells. m ranges from -1 to +1 through 0. Since m = -1, 0, +1, this means that all three sub-orbitals; 2px, 2py, 2pz are taken into consideration. Since all of these have 2 electrons each, the total number of electrons in them is 6.

Q132. 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.

Q133. Two rocket fuels below are determined by their high performance.N2H4(l) + O2(g) -> N2(g) + 2H2O(l) ΔH= -632 kJH2 (g) + ½ O2(g) -> H2O(l) ΔH = -286 kJIf 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.

Q134. 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: SHE is a redox electrode which forms the basis of oxidation-reduction potential. The standard electrode potential value of hydrogen is declared to be zero.

Q135. 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

Q136. The number of atoms present in a molecule determines its _.

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

Explanation: Correct option is D. Atomicity is defined as the number of atoms in the molecules of an element. Atomicity refers to the number of atoms present in a single molecule of an element, substance or compound. It can also be considered as the nature of molecules. According to the atomicity of a substance, it can be Mono, Di, Tri or Polyatomic. For example, oxygen or O2 is diatomic because it has 2 atoms in its molecule.

Q137. 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.

Q138. 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.

Q139. 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.

Q140. 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

Q141. 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.

Q142. 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.

Q143. 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.

Q144. The domestic electricity supply has a frequency of:

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

Explanation: The standard frequency for domestic electricity supply varies around the world, but it is commonly 50 Hertz (Hz). The specific frequency depends on the region and the standards established by the local electrical grid.It's important to note that the frequency of the electricity supply is a key parameter in electrical systems and devices, and appliances are designed to operate at the frequency of the local power grid.

Q145. A car going around a certain curve at a speed of 25 km/h has centripetal force of 100 N acting on it. If the speed of the car is doubled, the centripetal force:

• A. Is quadrupled✓
• B. Is doubled
• C. Is multiplied by √2
• D. Is reduced to 1/2 of the original value
• E. Is reduced to 1/6 of the original value

Explanation: The formula that will be used here will be: F=(m)(v)2/r. By doubling the speed of the car, the centripetal force should be quadrupled due to the power of 2.

Q146. 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: The bending of a beam of light around the corners of the obstacles is called diffraction. It occurs only when the wavelength is comparable to the size of the aperture. As the wavelength increases, the diffraction effect will also increase.Thus for greater diffraction, it is important that the size of the obstacle is directly proportional to the wavelength of the source. Suppose a is diffraction and λ is the wavelength a∝λ Hence for diffraction, the size of the obstacle should be in the order of a wavelength due to the wave nature of light.

Q147. 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:

Q148. When two bodies move towards each other with constant speed, the distance between them decreases at the rate 6m/sec. If they move 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 = 6V1 - V2 = 4Solving the equations simultaneously,V1 = 4 + V2Substituiting this in first equation,4 + V2 + V2 = 6 2V2 = 2V2 = 1 m/sV1 = 4 + V2 V1 = 4 + 1V1 = 5 m/s.Option A is the correct answer.

Q149. 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: Electrostatic force is a mutual force that will not act on a single charge.

Q150. Galilean's law is applied to:

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

Explanation: Galilean's law states that the laws of motion are the same in all inertial frames, which are frames that are either at rest or moving with a constant velocity. In these frames, objects follow Newton's laws without any additional forces. In contrast, non-inertial frames are accelerating, requiring fictitious forces (like centrifugal or Coriolis forces) to explain motion. Therefore, Galilean's law specifically applies to inertial frames, and not to frames of reference in general or all frames.

Q151. 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.

Q152. In the direction indicated by an electric field line:

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

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

Q153. 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: Power=Energy/time Energy=power ×time 60 watt×120 sec =7200 J =7.2 kilo J.

Q154. F = e(v x B) is valid for:

• A. Electron
• B. Proton
• C. Neutron
• D. Any charged particle✓

Explanation: The Lorentz force equation, F = e(v x B), is applicable to any charged particle because it describes the force experienced by a charged particle moving through a magnetic field. This includes positive charges like protons and negative charges like electrons. The direction of the force depends on the particle's charge and the magnetic field direction. Neutrons, being neutral, do not experience a force in a magnetic field, which is why they are not applicable in this equation.

Q155. 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 is a highly sensitive technique used to detect and measure trace elements in a mixture, especially when they are present in very small amounts or have similar chemical properties to other elements. By irradiating the sample, it becomes radioactive, and the subsequent measurement of emitted radiation allows for precise identification and quantification of the elements. Other methods like simple analysis lack the sensitivity required, while spectral analysis may face challenges with low concentrations or similar spectra. Geometric and mechanical analyses are unrelated to chemical detection.

Q156. 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)

Q157. 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.

Q158. 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/sspeed of neutron ( V)= 6.6 × 10⁴ m/snow ,kinetic energy = 1/2mv²K.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 jso,K.E = 37.2 × 10-19.Hence the correct answer is A which is closest to the correct answer

Q159. 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.

Q160. 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.

Q161. The flow of charges produces:

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

Explanation: Electric current is the rate of flow of charges. In electric circuits this charge is often carried by electrons moving through a wire.Current generally refers to the flow of charges. A stationary charge produces only electric fields whereas a moving charge produces both electric as well as magnetic fields.

Q162. A black body _ black body radiation.

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

Explanation: A black body is an idealized physical object that perfectly absorbs all incident electromagnetic radiation — it does not reflect or transmit any. In return, it emits radiation (black body radiation) depending on its temperature. Thus, it both emits and absorbs radiation, making:✅ Option C: Both Emits and Absorbs the correct and most complete answer.Ask ChatGPT

Q163. 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: According to Guass' Law flux through a surface is proportional to the charge enclosed at its center.

Q164. 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

Q165. Angular velocity cannot be

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

Explanation: Angular velocity cannot be infinite because it defies physical laws and is not achievable in practice, making option C correct. Additionally, angular velocity cannot be described as linear, which makes option D also correct. Therefore, the combined option 'C and D' is the correct answer. Options A and B are incorrect because angular velocity can indeed be zero or negative, representing no rotation or rotation in the opposite direction, respectively.

Q166. 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.

Q167. 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.

Q168. A current of 4.4 amperes is flowing 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.

Q169. 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 = 4q1Hence, A is the correct option

Q170. A force which is experienced in a magnetic field depends on:

• A. magnitude of charge q
• B. speed of the moving charge v
• C. magnitude of magnetic field B
• D. all of these✓
• E. none of these

Explanation: The force experienced by a charge moving in a magnetic field is given by the formula F = qvB sin(θ), where q is the charge, v is the velocity of the charge, and B is the magnetic field strength. The angle θ is the angle between the velocity vector and the magnetic field lines. Therefore, the force depends on the magnitude of the charge, the speed of the moving charge, and the strength of the magnetic field. Option D correctly identifies all these factors. Options A, B, and C each identify only one of these factors, which is insufficient on its own. Option E is incorrect as it suggests that the force depends on none of these factors, which is contrary to the established formula.

Q171. What is the flux density at a point 3 cm from the current carrying conductor, when there is a current of 25 A in a wire: (u0= 4𝜋 x10-7)

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

Explanation: The correct answer is 1.67x10-4T. To find the magnetic flux density (B) at a distance (r) from a long straight wire carrying current (I), you can use the formula:B = (μ0 * I) / (2 * π * r).Substituting in the values: μ0 = 4π x 10-7 T·m/A, I = 25 A, and r = 0.03 m (3 cm), we get:B = (4π x 10-7 * 25) / (2 * π * 0.03) = 1.67 x 10-4T.Other options are incorrect because:0.23x10-1T is too high, not matching the expected results.2.99x10-6T is too low compared to the calculations.3.63x10-8T is orders of magnitude smaller than expected.999x10-7T converts to an unreasonably high value of 0.0999 T.

Q172. 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: Formula for this case, when source is moving and observer is stationary, is: f' = f (v) / (v - vs) where: f = frequency of the sound emitted by the source v = speed of sound in air = 330 m/s vs = speed of the source Plugging in the values, we get: f' = 1800 x (330) / (330 - 50) = 1800 x 330 / 280

Q173. 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: First, calculate the speed of the neutron using the formula speed = distance/time. Here, the speed is 12 m / (3.6 x 10-4 s) = 3.33 x 104 m/s.Next, use the formula for kinetic energy: K.E = ½ mv2. Substituting the values, we have:K.E = ½ (1.7 x 10-27 kg) x (3.33 x 104 m/s)2 = 93 x 10-20 JConvert this energy from Joules to electronvolts (eV) using the conversion factor 1 eV = 1.6 x 10-19 J:K.E = (93 x 10-20 J) / (1.6 x 10-19 J/eV) = 5.78 eV.Thus, option B is correct. The other options result from incorrect calculations or conversion errors.

Q174. Isotopes means the addition of additional _ in the 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.

Q175. 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=CVCapacitance in series can be calculated as:1/C=1/C1 + 1/C21/C=1/12 + 1/241/C=2+1/241/C=⅛C=8 microfarads.->Q=CVQ=(8x10^-6)(360) Q=2880 x 10-6 C

Q176. 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.

Q177. 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.

Q178. 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: Increasing the wavelength of the light increases the spacing between different fringes since the spacing between different fringes is wavelength-dependent. Red light has the largest wavelength of the color spectrum with a range of 625 - 740 nm, while violet has the smallest wavelength with a range of 380 - 435 nm.The interference pattern changes. When the wavelength increases, there are fewer points of constructive and destructive interference. There's more space between the loud and quiet zones. Likewise, if you change the tone to decrease wavelength, there are more regions of interference.

Q179. When path difference between two waves are odd integral multiple of half the wavelength, the resultant effect is called:

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

Explanation: Destructive interference occurs when two waves with opposite phases (180 degrees out of phase) combine. In this case, the crests of one wave align with the troughs of the other wave, resulting in a cancellation of amplitudes. As a result, the resultant wave has a smaller amplitude or even zero amplitude at certain points.This phenomenon is commonly observed in various wave systems, such as sound waves, light waves, and water waves. It is characterized by the reduction or complete elimination of wave amplitudes at specific locations where destructive interference occurs.

Q180. 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

Q181. 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.

Q182. 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.

Q183. 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.

Q184. 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: In the equation F=−kx, where F represents the force exerted by the spring, k is the spring constant, and x is the displacement from the equilibrium position, the negative sign indicates that the force F is directed opposite to the displacement x. This means that when the displacement x is positive (away from the equilibrium position), the force F exerted by the spring is negative (directed towards the equilibrium position), and vice versa. Therefore, option A) correctly interprets the meaning of the negative sign in the equation.

Q185. 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: To find the internal resistance of the battery, we can use the formulas:1. The emf, E, is the open-circuit voltage: E = 2.2 V.2. When the battery is connected to a resistance of 5.0 Ω, the terminal voltage V = 1.8 V.Using Ohm's Law, V = IR, where I is the current flowing through the external resistance. Therefore, I = V/R = 1.8 V / 5.0 Ω = 0.36 A.The internal resistance, r, can be found using the formula E = V + Ir, so 2.2 V = 1.8 V + 0.36 A * r.Solving for r gives r = (2.2 V - 1.8 V) / 0.36 A = 1.11 Ω.The correct answer is 1.11 Ω.Other Options:Option A (9.11 Ω), Option B (2.11 Ω), Option C (3.11 Ω), and Option E (0.11 Ω) are incorrect as they result from miscalculations or misunderstandings of the relationship between emf, internal resistance, and external resistance.

Q186. 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: To find the area of each plate, we use the formula for the capacitance of a parallel plate capacitor: C = ε0 * (A/d), where C is the capacitance, ε0 is the permittivity of free space (approximately 8.85 x 10-12 F/m), A is the area of the plates, and d is the distance between the plates. Given C = 10 x 10-9 F and d = 0.885 x 10-3 m, we rearrange the formula to solve for A: A = (C * d) / ε0. Plugging in the values gives A = (10 x 10-9 F * 0.885 x 10-3 m) / 8.85 x 10-12 F/m = 1.0 m2. Thus, Option A is correct. The other options provide areas that are either too large or too small when calculated properly with the given values.

Q187. 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 NDistance = 1.75m + 0.5m = 2.25 mW.D= 2.25m x 500 N = 1125 J

Q188. 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: 19.8 N: This option is the correct value for the tension 'T' when the elevator is descended with an acceleration of 0.1 m/s². The tension in the cable can be calculated using the equation T = mg - ma, where 'm' is the mass of the body, 'g' is the acceleration due to gravity, and 'a' is the acceleration of the elevator. Substituting the given values, T = (20 N) - (0.1 m/s²) = 19.8 N.

Q189. 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: ½kxo2The gain in gravitational potential energy: mgh = mgxoThe 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.

Q190. 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: To solve this problem, apply the work-energy principle, which states that the work done on an object is equal to the change in its kinetic energy. Since the crate starts from rest, the initial kinetic energy is 0. The work done W is calculated by multiplying the constant force F by the displacement d: W = F × d = 5 N × 1 m = 5 J. This work done becomes the final kinetic energy of the crate, thus the correct answer is 5 J. Other options are incorrect as they do not match the calculation F × d using the given values.

Q191. 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.)

Q192. What happens when a 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.

Q193. 2 look at this series 7, 10, 8, 11, 9, 12. Which number you think will be next?

• A. 10✓
• B. 12
• C. 13
• D. 7

Explanation: This is a simple addition and subtraction series.In the first pattern, 3 is being added and in the second pattern, 2 is subtracted.

Q194. Look at these series: 14, 28, 20, 40, 32, and 64. What number should come next?

• A. 52
• B. 56✓
• C. 96
• D. 128

Explanation: If we notice the pattern, we are doubling a number, and then subtracting 8 from the product. This pattern is continuing throughout the series. 14, double it, 28, subtract 8, 20, double it, 40, subtract 8, 32, double it, 64If we continue this pattern, then64, subtract 8, 56Hence, 56 is our new number. So, option B is the correct option.

Q195. 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.

Q196. Look at this series 80, 10, 70, 15, 60. What number should come next?

• A. 20✓
• B. 25
• C. 30
• D. 50

Explanation: The series begins with 80, from which 10 is subtracted to get 70. Adding 5 to 70 yields 15, subtracting 10 from 15 results in 60. Following this alternating pattern, adding 5 to 60 gives 20, making Option A (20) the correct choice. Option B (25) mistakenly applies continuous addition, Option C (30) incorrectly adds 10, and Option D (50) repeats a subtraction step when addition is required.

Q197. 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.

Q198. 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: both the statements are effects because firstly evacuation takes place due to some cause so there are chances that something happened due to which the evacuation took place . The second statement is also an effect of some cause as government reached to help the people in the affected areas which clearly tells that some natural disaster took place due to which the government rushed to help the people in need