Pk Mdcat Mock 5 — Solved Past Paper with Answers

Q1. Neither they nor their friend _ solved the question.

• A. has✓
• B. have
• C. was
• D. were

Explanation: The key to solving these questions is to read this sentence in your head while filling each option in the blank. Since the pronouns make the sentence singular hence, the verb should be singular

Q2. She was feeling _ even after five hours of the surgery.

• A. Mumbled
• B. Haggard✓
• C. Pally
• D. Grope

Explanation: 'Mumbled' means to say something indistinctly and quietly, making it difficult for others to hear. 'Haggard' means looking exhausted and unwell, especially from fatigue, worry, or suffering. 'Pally' means having a close, friendly relationship. 'Grope' means to search blindly or uncertainly by feeling with the hands.

Q3. Identify errors in sentences:

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

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

Q4. Demonstrate correct use of articles and prepositions Demonstrate correct use of subject-verb agreement Demonstrate correct use of writing conventions of spelling, capitalization and punctuation to clarify meaning If you lend him a book (A)/ he will lend it (B), to someone else (C) and never you will get it back. (D)

• A. If you lend him a book
• B. He will lend it
• C. To someone else
• D. And you will never get it back✓

Explanation: Adverbs are placed after auxiliary verbs which include “will”. Hence, the correct option is "option D".

Q5. Choose the right option to complete the following sentence: The plot of this story is so _ that I can predict the outcome.

• A. Intricate
• B. Pivotal
• C. Trite✓
• D. Fictitious

Explanation: The purpose of this sentence is to show the plot is very basic and repetitive. Trite will be the best word here as it refers to lacking originality, and something being dull due to overuse.

Q6. In the following question, four alternative meanings of a word are given. Select the nearest correct meaning of the word given. INVIDIOUS:

• A. Unbreakable
• B. Interesting
• C. Unpleasant✓
• D. Fair

Explanation: Something that is likely to arouse or incur resentment or anger in others.

Q7. His credulous nature often landed him in trouble. What does credulous mean over here?

• A. Dreamy
• B. Naughty
• C. Innocent
• D. Willing to believe easily✓

Explanation: Credulous means being very naive, gullible, and innocent hence, having or showing too great a readiness to believe things.

Q8. Choose the correct passive voice: How did she defraud him of his savings?

• A. How had he been defrauded of his savings?
• B. How had he been defrauded by her?
• C. How was he defrauded of his savings?
• D. How was he defrauded by her of his savings?✓

Explanation: Option D is the only sentence, that has all the components of the main sentence, hence we will go with that option.

Q9. 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 himwhen she walks. He also pulls her wheelchair and turns lights on and off. When Mona dropssomething, 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. In paragraph 4, the author writes, “Mona’s classmates flock around Sam like geese.” Which of the following literary techniques is used in this sentence?

• A. Allusion, characterized by a reference to, or representation of, people, places, events, literary work, myths, or works of art, either directly or by implication
• B. Personification, characterized by giving human traits to nonhuman things, such as animals or objects
• C. Irony, characterized by the use of words to express the opposite of their usual meaning
• D. Smile, characterized by the making of a comparison using the words “like” or “as”✓

Explanation: The sentence in question uses the word “like” to compare Mona’s classmates to geese. Therefore the above sentence is a simile, making (D) the correct choice. The above sentence does not reference to, or representation of, people, places, events, literary work, myths, or works of art, either directly or by implication. Therefore, the above sentence is not an allusion. (A) is incorrect. Saying that “Mona’s classmates flock around Sam like geese” gives animal traits to human beings, not the reverse. Therefore, the above sentence does not use personification, and (B) is incorrect. Finally the phrase “flock around Sam like geese” uses words to express their ordinary meaning. Therefore, the above sentence does not use irony. So (C) is incorrect

Q10. Identify the underlined segment in the following sentence, which contains the mistake that needs to be corrected. We wish today was sunny so that we could spend the day in the country communicating with nature.

• A. Was✓
• B. So that
• C. Could spend
• D. In the country

Explanation: Intead of 'was', 'were' should have been used. We wish today were sunny.. These phrases are never correct: I wish I was, I wish it was, he wishes he was, she wishes she was. Always remember this rule about the usage of was and were: use were with expressions that are hypothetical, wishful, imagined, desired, doubtful, and otherwise contrary to fact—that is to say, not real.

Q11. Questions 7-8 are based on the following passage. The fact that we were all as safe as kittens under a cook-stove did not, however, assuage in the least the fine despair and the grotesque desperation which seized upon the residents of the East Side when the cry spread like a grass fire that the dam had given way. Some of the most dignified, staid, cynical, and clear-thinking men in town abandoned their wives, stenographers, homes, and offices and ran east. There are few alarms in the world more terrifying than The dam has broken! There are few persons capable of stopping to reason when that clarion cry strikes upon their ears, even persons who live in towns no nearer than five hundred miles to a dam.Identify the phrase in which the people of the East Side experienced one of the deadliest fears of their lives:

• A. "The dam has been destroyed"
• B. "The dam is safe"
• C. "The dam has broken"✓
• D. "The dam has not broken"
• E. "The dam is overflowing"

Explanation: It is clearly mentioned in lines 6 and 7 that dam was broken.

Q12. Demonstrate correct use of articles and prepositions Demonstrate correct use of subject-verb agreement Demonstrate correct use of writing conventions of spelling, capitalization and punctuation to clarify meaning I advised her _ drink it.

• A. Don't
• B. Not to✓
• C. To not
• D. To don't

Explanation: A preposition must be placed before the adverb. Hence, the correct option is option B.

Q13. 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. Which of the following would be the best title for this passage?

• A. Why Mona Loses Her Balance
• B. How Mona’s Service Dog Helps Her✓
• C. Sam Helps Mona at School
• D. Raising Money for the Humane Society

Explanation: A good title summarizes the main idea of the passage and lets the reader know what to expect should he or she read further. In paragraph 1, the author illustrates Mona's need for assistance with routine activities. In the beginning of paragraph 2, the author tells us that Mona has a service dog and explains that a service dog helps someone who has a physical problem. In paragraph 3, the author shows how Mona’s service dog helps her lead a fuller life. In the final paragraph, the author sums up the main ways that Mona’s service dog helps her. Using this information, we can understand that the main idea of this passage is to explain how Mona’s service dog, Sam, helps her. Therefore, the best title for the passage would be How Mona’s Service Dog Helps Her, since it best summarizes the main idea. Choice (B) is correct. The author never explains why Mona has trouble keeping her balance. So (A) is incorrect. The passage does show that Sam helps Mona at school (C), and that Mona raised money for her local humane society (D), but these are not main ideas. They are merely details the author uses to support a larger idea. Therefore they are incorrect.

Q14. Answer on passage: The high school math department needs to appoint a new chairperson, which will be based on seniority. Ms. West has less seniority than Mr. Temple, but more than Ms. Brody. Mr. Rhodes has more seniority than Ms. West, but less than Mr. Temple. Mr. Temple doesn't want the job. Who will be the new math department chairperson?

• A. Mr. Rhodes✓
• B. Mr. Temple
• C. Mr. West
• D. Mr. Brody

Explanation: Mr. Temple has the most seniority, but he does not want the job. Next in line is Mr. Rhodes, who has more seniority than Ms. West or Ms. Brody.

Q15. Read the passage to answer the question: What is life? A little scum of no importance on the surface of an unimportant globe circling round a second-rate star? An accidental conglomeration of atoms which have come together by an odd chance, the result of an exceedingly improbable happening? That is what some astronomers would have us think. Looking out into the depth of space, they have discovered a universe of unthinkable dimensions. A billion suns in our own galaxy, beyond it perhaps a billion galaxies, only revealed to us as tiny smudges on a photographic plate. No wonder they are impressed by the enormous disparity between the scaffolding and the result. Life seemed to be, as Jeans said, ‘an utterly unimportant by-product’ in a universe which was clearly not designed for life, and which, to all appearances, is either totally indifferent or definitely hostile to it’. It seemed ‘incredible that the universe can have been designed primarily to produce life like our own; had it been so, surely we have might expected to find a a better proportion between the magnitude of the mechanism and the amount of the product. The title of the passage can be:

• A. Gathering of atoms
• B. The life outside the earth
• C. Universe and it's unneeded vastness
• D. Life versus universe✓

Explanation: In this passage, the author can be seen talking about the majesty of the universe with respect to the existence of “life” in various respects. Hence the best title to this will be Life Versus Universe.

Q16. Identify the underlined segment in the following sentence, which contains the mistake that needs to be corrected.It should also help you to understand how can you make better use of the scientific method in your everyday living.

• A. To understand
• B. Can you✓
• C. Use of
• D. Living

Explanation: If ‘can you’ was altered to ‘you can’, it would enable the sentence to make more sense, as it is a statement one is saying to the other as a suggestion. The remaining three underlined words/phrases do not need to be corrected.

Q17. Given figures shows:

• A. Structure of Lenticel✓
• B. Hydathode showing gaseous vapour exchange
• C. Fungus reproducing by spore formation
• D. Algae reproducing by spore formation

Explanation: The figure shows the structure of 'Lenticel', which facilitates gaseous exchange and transpiration. These are aerating pores in the bark of woody trees. These are surrounded by loosely arranged thin walled complementary cells, enclosing intercellular spaces for gaseous exchange.

Q18. Four words are shown below:Branchioceranthus - sexual reproduction - nutritive - HydraThese words can be used in the spaces P, Q, R, and S to complete the sentence below:The coelenterates range in size from microscopic _P_ to macroscopic, _Q_, a hydrozoan polyp that may reach two meters in length. Cnidarians are found in two basic forms: the polyps and the medusae. Polyps are cylindrical animals, which in most cases are _R_ in function, hence named as gastrozooids. The medusae are umbrella-like in form. These are free-swimming. The medusae are involved in _S_ as they have gonads.

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

Explanation: Branchioceranthus is macroscopic and hydra is microscopic. P = Hydra Q =Branchioceranthus R = nutritive S= Sexual reproduction

Q19. If lipopolysaccharides did not appear in the wall of bacteria on staining then it will be known as _.

• A. Gram negative
• B. Gram positive✓
• C. Capsule
• D. Both Gram positive & negative

Explanation: The Gram stain procedure distinguishes between Gram positive and Gram negative groups by coloring these cells red or violet. Gram positive bacteria stain violet due to the presence of a thick layer of peptidoglycan in their cell walls, which retains the crystal violet these cells are stained with. Alternatively, Gram negative bacteria stain pink, which is attributed to a thinner peptidoglycan wall, which does not retain the crystal violet during the decoloring process.Gram-positive bacteria do not contain lipopolysaccharides, but carry surface teichoic acids, lipoteichoic acids and peptidoglycan instead.The outer membrane of Gram-negative bacteria contains lipopolysaccharides, proteins, and phospholipids.The bacterial capsule is a large structure of many bacteria. It is a polysaccharide layer that lies outside the cell envelope, and is thus deemed part of the outer envelope of a bacterial cell.

Q20. Spirochete is an example of which type of bacteria?

• A. Aerobic
• B. Facultative
• C. Anaerobic✓
• D. Both Options A and B are correct

Explanation: Spirochaeta are free-living nonpathogenic inhabitants of mud and water, typically thriving in anaerobic (oxygen-deprived) environments

Q21. If more substrate is added to an already occurring enzymatic reaction, and more enzyme activity is seen, then this is because of which of the following?

• A. There is probably more substrate present than there is enzyme
• B. There is probably more product present than there is either substrate or enzyme
• C. The enzyme substrate complex is probably failing to form during the reaction
• D. There is probably more enzyme available than there is substrate✓

Explanation: When more substrate is added to already occurring enzymatic reaction and it is seen that activity has been increased this means that there are more enzyme available than substrate so that new added substrates make enzyme substrate complex with the available extra enzymes.OPTION A: If there is more substrate than there are enzymes than the product formation ceases and activity of enzyme decreases.OPTION B: It is not possible.OPTION C: One substrate, one enzyme forms one substrate complex and if more substrate is present than this complex fails to be formed.OPTION D: If more enzyme is available than substrate this means that there are more enzyme available than substrate so that new added substrates make enzyme substrate complex with the available extra enzymes.

Q22. Under the microscope, the bacteria appear a bluish-purple color. Which class of bacteria are on the slide?

• A. Helix
• B. Around
• C. Rod✓
• D. Rigid helix

Explanation: c) Rod: The correct answer is option (c) "Rod." Rod-shaped bacteria are also known as bacilli. They have a cylindrical or rod-like shape. When stained using the Gram stain technique, some rod-shaped bacteria appear bluish-purple under the microscope. The color is a result of the Gram stain's interaction with the bacterial cell wall, which helps in the classification of bacteria based on their cell wall composition.

Q23. Booklungs serve the function of respiration in:

• A. Scorpion✓
• B. Earthworm
• C. Frog
• D. Cockroaches
• E. Fish

Explanation: A book lung is a type of respiration organ used for atmospheric gas exchange that is present in many arachnids, such as scorpions and spiders. Each of these organs is located inside an open ventral abdominal, air-filled cavity (atrium) and connects with the surroundings through a small opening for the purpose of respiration.

Q24. The first viral disease namely _ was discovered in 1892.

• A. Hepatitis
• B. AIDS
• C. Rabies
• D. Tobacco mosaic disease✓

Explanation: Tobacco mosaic disease, caused by the tobacco mosaic virus, infects plants. It causes the leaves to become wrinkled, discolored, and mottled. It was discovered by Dmitry Ivanowsky.

Q25. The only promoter of Leaf's senescence in the following plant hormones is:

• A. Gibberellins
• B. Cytokinins
• C. Auxins
• D. Abscisic acid✓

Explanation: Abscisic acid is a plant hormone that promotes leaf senescence and is involved in stress responses, such as drought and salt stress.

Q26. Find the mass in grams of 1.69 mol of phosphoric acid.

• A. 165.6 g✓
• B. 157 g
• C. 148 g
• D. 138 g

Explanation: Moles = Mass / molar mass Moles x molar mass = mass in grams Molar mass of phosphoric acid H₃PO₄ = 98 g / mol 1.69 mol x 98 g /mol = mass in grams Mass = 165.6 g

Q27. The expression for the radius of the nth orbit of a hydrogen atom was derived by:

• A. Planks
• B. Bohr✓
• C. Rutherford
• D. Einstein

Explanation: The expression for the radius of the nth orbit of a hydrogen atom was derived by Bohr. According to Bohr's theory of the hydrogen atom, Bohr was able to derive the formula for the hydrogen spectrum using basic physics.

Q28. Which of the following catalyst is used in the industrial preparation of methanol?

• A. Zinc oxide and alumina
• B. Alumina and silica
• C. Silica and Chromium oxide
• D. Zinc oxide and Chromium oxide✓

Explanation: The industrial preparation of methanol usually involves a catalyst composed of zinc oxide and chromium oxide. This catalyst is known as a copper-zinc-chromium catalyst, and it is commonly used in the synthesis of methanol from a mixture of carbon monoxide and hydrogen gases in a process known as the "methanol synthesis gas." This catalytic process is known as the "low-pressure methanol synthesis" and is widely used in industry.

Q29. What is the unit of slope obtained from Arrhenius equation?(slope=-Ea/2.303R)

• A. K¯
• B. J/mol K
• C. K✓
• D. Mol/K

Explanation: The slope is given by -Ea/2.303R. The units for activation energy or Ea are Jmol−1 and those for R are JK−1mol−1. By dividing Ea by R, K is obtained which is the unit of the slope.

Q30. Rate = K [N2O5 ] has _ of reaction.

• A. First order✓
• B. Pseudo first order
• C. Second order
• D. Third order
• E. Pseudo order

Explanation: The order of the reaction is the sum of all the exponents of reactants in the rate equation. Since the sum of exponents of reactants in this equation is 1. The order of reaction, in this case, is equal to 1.

Q31. What is the major product of the nitration reaction below?

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

Explanation: The answer to the above question A since Br is an ortho-para directing group it sends NO2 to the Ortho Para position which is 1,3 and 5.Since 1 and 3 are already occupied the new compound formed has NO2 at 5th position.

Q32. Which of the following have the same number of molecules?

• A. 200 cm2 of Carbon dioxide and 500 cm2 of oxygen
• B. 300 cm2 of Carbon dioxide and 150 cm2 of oxygen
• C. 300 cm2 of Carbon dioxide and 150 cm2 of oxygen
• D. 300 cm2 of Carbon dioxide and 300 cm2 of oxygen✓

Explanation: 300 cm2 of Carbon dioxide and 300 cm2 of oxygen would have the same number of molecules since the number of moles in question is equal, thus the number of molecules would also be the same.

Q33. One Calorie is equal to:

• A. 4.18 KJ
• B. 4.18 J✓
• C. 0.418 KJ mol-1
• D. 0.418 KJ

Explanation: 1 cal equals 4.18 J. It is very often confused with 1 Kcal which equals to 4.18 KJ

Q34. Which step should be repeated over and over to get a variety of substituted products?

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

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

Q35. During oxidation of unsymmetrical ketones which atom is oxidized?

• A. Carbonyl carbon
• B. Carbon attached to smaller number of hydrogen atom✓
• C. Carbon attach to larger number of hydrogen atoms
• D. Hydrogen

Explanation: The oxidation of unsymmetrical ketones involves the cleavage of the carbon-carbon bond adjacent to the carbonyl group. The carbon atom that is attached to fewer hydrogen atoms is more electron deficient and therefore more susceptible to oxidation. This carbon atom is oxidized, and the other carbon atom is reduced. The result is the formation of two different carboxylic acids.

Q36. If the lowest energy X-rays have λ = 4.0 x 10-8 m , estimating the minimum difference in energy between two Bohr orbit, where an electronic transition would correspond to the emission of an X-ray, at what minimum Z (atomic number) would a transition from the second energy level to the first result in the emission of an X-ray?

• A. Z=2✓
• B. Z=3
• C. Z=4
• D. Z=5

Explanation: This is the following solution:

Q37. If a graph is plotted between pressure on x- axis and volume on y- axis for Boyle's law verification, the curve obtained is called

• A. pseudotherm
• B. isotherm✓
• C. biotherm
• D. all of these

Explanation: If a graph is outlined in between pressure on the x-axis (abscissa) and volume on the y-axis (ordinate), then a curve is obtained. This curve is called isotherm 'iso' implies the same, “therm” implies heat.

Q38. This is is a structure of:

• A. Menadione✓
• B. 𝛂 - Tocopherol
• C. Calciferol
• D. Thiamine
• E. Pyridoxine

Explanation: The above structure is of Menadione.

Q39. Formation of Hydrogen molecule according to VBT theory involves overlap of _ ?

• A. 1s orbital✓
• B. 2s orbital
• C. 2p orbital
• D. 2px orbital

Explanation: The formation of the hydrogen molecule can be explained using the Valence Bond Theory. According to VBT, atoms form bonds by sharing valence electrons. In the case of H2, each hydrogen atom has one valence electron in its 1s orbital. When the two hydrogen atoms approach each other, their 1s orbitals overlap to form a molecular orbital that is shared between the two atoms. This molecular orbital is called a sigma (σ) bond.

Q40. The unit cell parameters of the monoclinic system are:

• A. a = b ≠ c ; α=β=γ=90
• B. a ≠ b ≠ c ; α=γ=90 ; β≠90✓
• C. a ≠ b = c ; α=β=90; γ≠90
• D. a = b = c ; α=β=γ=90

Explanation: According to the crystal systems in the table given below, option B is correct.

Q41. Which one among the following is the strongest reducing agent: Fe2+ + 2e -> Fe (-0.44V) Sn2+ + 2e -> Sn (-0.14 V) Ni2+ + 2e -> Ni (0.25 V) Fe3+ + e -> Fe2+ (-0.77 V)

• A. Fe3+✓
• B. Ni
• C. Fe2+
• D. Sn

Explanation: The species with the lowest electrode potential is the strongest reducing agent i.e. Fe3+

Q42. The strength of an acid depends on?

• A. Ease of removal of proton
• B. Stability of the anion formed
• C. Stability of the cation formed
• D. Depends on both ease of removal of proton and stability of the anion formed✓

Explanation: The correct option is: Depends on both ease of removal of a proton and stability of the anion formed.Explanation:The strength of an acid is determined by its ability to donate a proton (H+) in a chemical reaction. This is often represented by the equation:Acid (AH) ⇌ H+ + Anion (A-)In this equation, the acid (AH) donates a proton (H+) to form the conjugate base or anion (A-). The strength of an acid is influenced by two main factors:Ease of removal of a proton: The more readily an acid can donate a proton, the stronger it is. Acids with weak bonds between hydrogen and the rest of the molecule are more likely to lose the proton and, thus, are stronger acids.Stability of the anion formed: After the acid donates its proton, the resulting anion (conjugate base) is formed. A stable anion is better able to handle the negative charge that results from gaining an electron. An unstable or highly reactive anion will make the acid weaker.Together, these factors play a crucial role in determining the strength of an acid. Acids with both a high tendency to release protons (ease of removal of a proton) and produce stable anions are considered strong acids. On the other hand, weak acids have a lower tendency to donate protons and/or form less stable anions.In summary, the strength of an acid depends on both the ease of removal of a proton and the stability of the anion formed after the proton donation.

Q43. Which of following has "higher boiling"and "melting point"?

• A. Acetone
• B. 2 - Butanol✓
• C. Propane
• D. 2 - Methylpropene

Explanation: OPTION A: Acetone has a boiling point of 56.5°C and a melting point of -94.9°C. It is a relatively small molecule and lacks the ability to form hydrogen bonds, resulting in weaker intermolecular forces. OPTION B: 2-butanol has a higher molecular size and the presence of an -OH group, allowing for intermolecular hydrogen bonding. Hydrogen bonding leads to stronger intermolecular forces, resulting in higher boiling and melting points. 2-butanol has a boiling point of 99.5°C and a melting point of -114.5°C. Hence, B is the correct option. OPTION C: Propane (C3H8) is a small molecule with weak London dispersion forces between its nonpolar molecules. It has a boiling point of -42.1°C and a melting point of -187.7°C. OPTION D: 2-methyl propene (also known as isobutylene) (C4H8) is also a small molecule with weak intermolecular forces. It has a boiling point of -6.9°C and a melting point of -159.7°C.

Q44. If the e/m value of electron is 1.7588 x 1011 C/kg, then what would be the mass of electron in grams (charge on electron is 1.6022 x 10-19 coulombs)?

• A. 9.1095 x 10-31 g
• B. 91.095 x 10-31 g
• C. 9.1095 x 10-28 g✓
• D. 0.919095 x 10-33 g

Explanation: If e/m is equal to 1.7588x10^11 and the charge on an electron is 1.6 x10^-19 then the mass can be calculated as: 1.7588x10^11=1.6x10^-19/m m-9.109 x 10^-31kg. In g, 9.1x10^-28 g As it is numerical, it can have only one possible answer.

Q45. The molecular structure of a hydrocarbon is shown below.

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

Explanation: B is a structural isomer of the structure shown above. Structure in A is the same as the structure shown. Structure C is not an isomer because it does not have the same number of carbon and hydrogen atoms as in the diagram shown. Structure D has a double bond that reduces two hydrogen atoms from it as compared to the structure shown that is why D can not also be an isomer of the diagram shown above.

Q46. A photon of wavelength 12.7 xl 5 m-1 is emitted when it jumps from higher to n = 1, what will be a higher orbit?

• A. n = 2
• B. n = 3
• C. n = 4✓
• D. n = 5

Explanation: The wavelength of the emitted photon: R (1/n 2/2 -1/n 2/1) use this formula to get the answer.

Q47. The compression factor (compressibility factor) for one mole of a Van der Waals gas at 00 C and 100 atmosphere pressure is found to be 0.5. Assuming that the volume of gas molecule is negligible, calculate the Van der Waals constant 'a'.

• A. 1.254✓
• B. 2.87
• C. 3.76
• D. 1.34

Explanation: This is the following solution.

Q48. A diabetic person’s exhaled breath contains propanone. A student tries to test the diabetes by asking the person to bubble the reagent with his exhaled breath. Which of the following reagents would give a positive result?

• A. Aqueous Bromine
• B. Fehling’s reagent
• C. Tollen’s reagent
• D. Alkaline aqueous iodine✓

Explanation: Propanone contains the R-CO-CH3 group hence it gives a positive triiodomethane or iodoform test. Iodoform test is used to check the presence of carbonyl compounds with the structure R-CO-CH3 or alcohols with the structure R-CH(OH)-CH3 in a given unknown substance. The reaction of iodine, a base, and a methyl ketone gives a yellow precipitate along with an “antiseptic” smell.

Q49. Born Haber cycle is used to determine:

• A. Electron affinity
• B. Lattice energy
• C. Crystal energy
• D. All of the above✓

Explanation: As we know that the electron affinity can be calculated by using Born Haber cycle.Lattice energy can be calculated by using Born Haber cycle.Crystal energy can be calculated by using Born Haber cycle.Born Haber cycle is used to determine the electron affinity, lattice energy and crystal energy.According to the above discussion, we conclude Born Haber cycle is used to determine the electron affinity, lattice energy and crystal energy.Hence, the option D is the correct answer. Because all the options match with the question.

Q50. Which of the following compounds possesses a single covalent bond between carbon and hydrogen?

• A. CH4
• B. C2H2
• C. C2H4
• D. All of the above✓

Explanation: All of the compounds contain a single covalent bond between carbon and hydrogen atoms. Only that C2H2 and C2H4 contain triple and double bonds between carbon atoms respectively.

Q51. Which of the following reactions is used for the production of alcohols on industrial scale?

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

Explanation: Option A describes a reaction that produces alkanes from alkenes. Option B describes a reaction that produces alcohol from alkenes so, it is correct. Option C describes a reaction that produces alkyl halides from alkenes. Option D describes a reaction that produces glycol from alkenes, which is a type of alcohol but not the type that is produced on an industrial scale for commercial use.

Q52. Paramagnetic behaviour of transition elements is due to the presence of:

• A. s electrons
• B. Unpaired electrons✓
• C. Paired electrons
• D. Outer d electrons

Explanation: Option B is correct as paramagnetism (the ability of a material to be weakly attracted to a magnet due to its magnetic field, which induces an internal magnetic field of the material) is caused by the presence of "unpaired electrons", with each electron having a magnetic moment associated with its spin angular momentum and orbital angular momentum.

Q53. A 4s orbital has:

• A. One node
• B. Two nodes
• C. three nodes✓
• D. O nodes

Explanation: 4s orbital has 3 radial nodes plus 0 angular nodes

Q54. The flavour of amyl butyrate is:

• A. Mango
• B. Raspberry
• C. Apricot✓
• D. Orange

Explanation: c) Apricot: Amyl butyrate is often used to impart an apricot-like aroma and flavor. Therefore, the flavor of amyl butyrate can be described as apricot-like.

Q55. The IUPAC name of the following compound is:

• A. 1-Ethyl-2, 4-dimethlycyclohexane✓
• B. 2-Ethyl-1,4-dimethylcyclohexene
• C. 2-Ethyl-1, 1-dimethylcyclohexane
• D. 4-Ethyl-1, 2-dimethylcyclohexane

Explanation: The IUPAC name of the compound is 1-ethyl-2,4-dimethylcyclohexane. The parent compound is cyclohexane. The carbon to which ethyl is attached is considered carbon 1 according to alphabetical order. The two methyl groups are on carbon 2 and 4 respectively.

Q56. The cation that distort the electron cloud of NO3− ion more and facilitates its decomposition is:

• A. Li+
• B. Mg++
• C. Cs+
• D. Be++✓

Explanation: Polarizability refers to the ability of a cation to distort the electron cloud of an anion in an ionic compound and the anionic cloud is pulled towards the cation when it gets distorted. According to Fajan’s rule, the greater charge density(charge/size) on a cation leads to greater distortion. Due to higher charge and smaller size, the charge density of Be++ is and so it will distort the electron cloud of NO3- more facilitating its decomposition.

Q57. Enthalpy of a compound is equal to its

• A. Heat of combustion
• B. Heat of formation✓
• C. Heat of solution
• D. Heat of dilution

Explanation: The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, so the answer is B. The enthalpy of combustion of a substance is defined as the heat energy given out when one mole of a substance burns completely in oxygen. The heat of solution also referred to as the enthalpy of solution or enthalpy of dissolution, is the enthalpy change associated with the dissolution of a solute in a solvent heat of dilution, or enthalpy of dilution, refers to the enthalpy change associated with the dilution process of a component in a solution.

Q58. If the total energy of an electron in the first shell of an H-atom is –13.6 eV, then its potential energy in the 1st excited state would be:

• A. +6.8 eV
• B. +20.4 eV
• C. – 6.8 eV✓
• D. +3.4 eV

Explanation: This is the following solution: The energy of an electron in its nth orbit = -13.6/n2. For first excited state n=2 T.E in first excited state = -13.6/4 = -3.4 eV P.E = - 2ke2/r T.E = -ke2/r P.E = 2 (T.E) PE in the first excited state = -6.8 eV.

Q59. A correct formula must:

• A. Be balanced with proper coefficients
• B. Always have subscripts
• C. Always conform to the valency rules
• D. Always conforms to the law of multiple proportions✓

Explanation: A correct formula must follow the law of multiple proportions(OPTION D) i.e that when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers. Option A is wrong because formulas do not have coefficients. Option B is wrong because not all formulas have subscripts. Option C is also wrong because sometimes there are certain formulas made exclusive of valency rules.

Q60. Study the following redox reaction and answer the following question: 10Clˉ +16H+ + 2MnO4ˉ → 5Cl2 + 2Mn2+ + 8H2O

• A. Manganese is oxidized from +7 to +2
• B. Chlorine ions are reduced from -1 to zero
• C. Chlorine is reduced from 0 to -1
• D. Manganese is reduced from +7 to +2✓

Explanation: The correct change in oxidation numbers

Q61. The rate of a gaseous reaction Is given by K [A] [B]. If the volume of the vessel containing these gases is reduced to 1/4th of the initial volume, the rate of reaction relative to the original rate would be:

• A. 16/1✓
• B. 1/16
• C. 4/1
• D. 1/8
• E. 8/1

Explanation: If the volume of the vessel is reduced by 1/4th that means according to formula C=n/V concentration of each gas in the flask increases by a factor of 4 times. Since concentrations of two gases are increased by this factor that increases the overall rate by 4x4=16.

Q62. On hydrogen atom spectrum, series of spectral lines within visible region is:

• A. Lyman series
• B. Balmer series✓
• C. Paschen series
• D. Brackett series
• E. Pfund series

Explanation: Four of the Balmer lines are in the technically "visible" part of the spectrum, with wavelengths longer than 400 nm and shorter than 700 nm. Parts of the Balmer series can be seen in the solar spectrum. H-alpha is an important line used in astronomy to detect the presence of hydrogen.

Q63. Why is it necessary to distill aldehyde formed from oxidation of primary alcohol through acidified potassium dichromate (VI) solution or acidified sodium dichromate (VI) solution?

• A. Aldehyde formed may be oxidized further to carboxylic acid concerned✓
• B. Aldehyde formed is unstable and decompose back to original precursor i.e. primary alcohol
• C. Aldehyde may be oxidised further to a ketone
• D. Aldehyde formed may react with primary alcohol, the original reactant.

Explanation: Oxidation of alcohols to aldehydes is partial oxidation, if aldehydes are further oxidized they form carboxylic acids. Therefore, the conditions required for making aldehydes are heat and distillation.

Q64. A rotating wheel of radius 0.5 m has an angular velocity of 5 rad/s at some instant and 10 rad / s after 5 s. Find the angular acceleration of a point on its rim.

• A. 1 rad / s2✓
• B. 3 rad / s2
• C. 5 rad / s2
• D. 7 rad / s2
• E. 9 rad / s2

Explanation: Explanation is given below

Q65. Doubly ionized atoms 𝑋 and 𝑌 of two different elements are accelerated through the same P.D. on entering a uniform magnetic field they describe circular paths of radii 𝑅1 and 𝑅2. The masses of 𝑋 and 𝑌 are in the ratio of:

• A. R1: 𝑅2
• B. 𝑅2: 𝑅1
• C. R21 : 𝑅22✓
• D. R22: 𝑅21

Explanation: Refer to the following

Q66. Magnetic flux is maximum when the angle, between the area vector and the magnetic field lines, is?

• A. 0°✓
• B. 90°
• C. 120°
• D. All of these

Explanation: Magnetic Flux refers to the number of magnetic field lines, passing through a particular area. The formula, to calculate magnetic flux, is; BA cos(theta), where 'B' is the magnetic flux density, 'A' is the area, and 'theta' is the angle between the two vectors. When theta is zero, which implies that the two quantities are parallel to each other, magnetic flux would be 'BA', which is the maximum amount.

Q67. Moment of inertia of a thin rod of mass m, length l about a line passing through its center is:

• A. ml2
• B. ½ ml2
• C. ⅓ ml2
• D. ⅖ ml2
• E. 1/12 ml2✓

Explanation: Moment of inertia of a thin rod of mass M and length L about an axis passing through its center is 1/12ML2.

Q68. Equations of kinetics are valid only when the acceleration is:

• A. Increasing
• B. Decreasing
• C. Constant✓
• D. Vary with time

Explanation: The equations of kinetics can be utilized for any motion that can be described as being either a constant velocity motion (an acceleration of 0 m/s/s) or a constant acceleration motion. They can never be used over any time period during which the acceleration is changing.○Equations of kinetics are only valid in uniform motion or non- accelerating motion or constant acceleration (a=0).

Q69. To determine the resistance of a voltmeter by discharging a capacitor through it, the instantaneous voltage is then given by the relation:

• A. A✓
• B. B
• C. C
• D. D

Explanation: Refer to the

Q70. The six strings of a guitar are the same length under nearly the same tension, but they have different thicknesses. On which string do waves travel the fastest?

• A. The thickest string
• B. The thinnest string✓
• C. The wave speed is the same on all the strings
• D. None of the above

Explanation: The velocity of a transverse wave in a stretched string is given by: v = √(T/n). Where T is the Tension and n is the mass per unit lenth n = m/L = ρπr^2/L where r is the radius of the wire r = d/2 where d is the diameter So, v = √ (4T/ρπd^2) v= 2/d √(T/ρπ) As it can be seen, v is inversely proportional to d Thus, the velocity of wave is highest for thinnest string.

Q71. A disc, a hoop, and a sphere of the same mass and radius are rolled down from a frictionless, inclined plane. Which has a greater speed on reaching the ground?

• A. Disc
• B. Loop
• C. Sphere✓
• D. All have the same speed

Explanation: The sphere has most of its mass near the axis of rotation, so it will have the smallest moment of inertia and will reach the ground first. a massive axis on two very light wheels, with negligible moment of inertia, will be even faster than the sphere. The disc has its mass uniformly distributed, so will have a greater moment of inertia and will arrive second. The hoop has all its mass concentrated away from the center, so will have the greatest moment of inertia. It will arrive last, but will then travel farther away on the horizontal plane than the other shapes, as it will have stored more of the original potential energy in the form of rotational energy.

Q72. “The magnitude of electrostatic acceleration force between two point charges is directly proportional to the product of the magnitude of the charges and inversely proportional to the square of the distance between them.” This is known as:

• A. Gauss’s Law
• B. Ohm’s law
• C. Faraday's law
• D. Newton's Law
• E. Coulomb's Law✓

Explanation: Coulomb’s law states that magnitude of electrostatic acceleration force is directly proportional to the product of the magnitude of two charges and inversely proportional to the square of the distance between them.

Q73. A 70 kg sportsman runs up a long flight of stairs in 4 seconds. The vertical height of the stairs is 4.5 m. What will be his power output in watts?

• A. 7.7 x 10² W✓
• B. 8.8 x 10³ W
• C. 9.5 x 10³ W
• D. 10.2 x 10⁴ W
• E. 13.5 x 10² W

Explanation: Given: m=70kg t=4s d=4.5 Formula: Power=Work/time P=Fd/t Solution: P=ma×d/t P=70(10)(4.5)/4 = 7.7×10² W

Q74. Two resistors R1 and R2 may be connected either in series or in parallel across a battery of zero internal resistance. It is required that the joule heating for parallel combination be five times that for series combination. If R1 = 100Ω, find possible values of R2.

• A. 38.2 Ω✓
• B. 35.3 Ω
• C. 48.2 Ω
• D. None of the above

Explanation: Correct option is 'A'.

Q75. Who stated the right-hand thumb rule?

• A. Oersted
• B. Maxwell
• C. Einstein
• D. Fleming✓

Explanation: The right-hand thumb rule was invented by British physicist John Ambrose Fleming in the late 19th century for use in electromagnetism.

Q76. A cathode ray oscilloscope is displaying an AC signal. If one wave is completed in 2 cm along X- axis and time-base setting is 10 ms/cm, then frequency of AC signal will be:

• A. 100 Hz
• B. 50 Hz✓
• C. 20 Hz
• D. 10 Hz
• E. 200 Hz

Explanation: The answer is B. We can find the time taken to create a single wave with the help of the time base and the length of the wave on the CRO. 2cm would be multiplied by the time base settings which is 10ms/cm to get 20ms which is the time taken for a single wave to be formed. As 1/Time period is the frequency, 1/20ms gives us 50Hz.

Q77. The angular velocity of a rotating disk increases from 2 rad/s to 5 rad/s in 0.5s. What is the disk’s average angular acceleration?

• A. 67 rad/s2
• B. 46 rad/s2
• C. 36 rad/s2
• D. 16 rad/s2
• E. 6 rad/s2✓

Explanation: Average angular acceleration = Rate of change of angular velocity = (Final angular velocity - Initial angular velocity) / Time = (5 rad/s - 2 rad/s) / 0.5 s = 6 rad/s²

Q78. After a certain lapse of time, the fraction of radioactive polonium is found to be 12.5% of the initial quantity. If the half-life of polonium is 138 days, then the duration of time-lapse is _days.

• A. 34.5
• B. 276
• C. 414✓
• D. 125

Explanation: .Let N be the initial quantity of radioactive polonium. After one half-life (i.e., 138 days), the quantity of polonium remaining will be N/2. After two half-lives (i.e., 276 days), the quantity of polonium remaining will be (N/2)/2 = N/4. After three half-lives (i.e., 414 days), the quantity of polonium remaining will be (N/4)/2 = N/8. So, if the fraction of polonium remaining is 12.5% (i.e., 1/8) of the initial quantity, then three half-lives have passed, and the duration of time-lapse is 3 x 138 days = 414 days.

Q79. Two capacitors C1 (6µF) and C2 (12µF) are in series across a 180 volts D.C supply. Calculate the charges on C1 and C2 respectively.

• A. 120x106 C, -420x106 C
• B. 320x10-6 C, 420x10-6 C
• C. 420x10-6 C, 320x10-6 C
• D. 720x10-6 C, 720x10-6 C✓
• E. 620x10-6 C, 420x10-6 C

Explanation: Charge remains same in series and charges of both capacitors are only same in Option D and so it is the right answer. You can even calculate the charge using this; net capacitance in series: 1/C= 1/C1 + 1/C2 1/C = 1/12 + 1/6 C= 4x10-6 F C=Q/V 4x10-6 = Q/180 Q= 720 x 10-6 C

Q80. Which of the following is the angle of projection of a projectile if its range is equal to its height?

• A. 48
• B. 60
• C. 90
• D. 76✓

Explanation: This value should be learned for the exam because of the unavailability of calculators during the exam. There is a neat formula for the ratio of height to range: h/r=tanθ/4 So whatever angle has a tangent of 4, that’s the angle that sets the ratio of height to range equal to exactly 1. tan−1(4)=75.96°

Q81. A shell of mass m moving with velocity v suddenly breaks into two pieces. The part having mass m/4 remains stationary. The velocity of the other shell will be:

• A. v
• B. 2v
• C. 3v/4
• D. 4v/3✓

Explanation: Using the law conservation of mass, Total momentum Before = Total momentum After Let x be the new speed of remaining mass (3m/4) mv = m1v1 + m2v2 mv = (m/4) (0) + (3m/4) (x) mv = (3m/4) x 4v/3 = x Options A, B and C cannot be derived from the given situation as they donot follow law of conservation of momentum.

Q82. Work done by friction force is always:

• A. Negative
• B. Positive
• C. Zero
• D. Maybe positive, maybe negative, or maybe zero✓

Explanation: The work done by frictional force will be positive when the displacement of the body is in the direction of the force. This can be understood by an example. Consider there are two blocks stacked one over the other. If the lower block starts to move slowly in one direction, then there is a frictional force between the two blocks that prevents the sliding of the two blocks. This force acts on the upper block in the direction of motion of the lower block. The upper block also moves along with the lower block, that is, in the direction of the frictional force. Hence, the work done by friction is positive in this case.The work done by friction can be negative. For example, when a block is sliding over a rough ground, the frictional force acts in a direction opposite to the direction of motion of the block and tries to bring it to a stop. Since, the direction of motion of the block and the direction of frictional force is opposite to each other, the work done by friction is negative.The work done by friction can also be zero. For example, if we try to push a very heavy block on a rough floor, the block does not move. This is because the force of static friction opposes our force. However, since the block does not move, the displacement is zero. Therefore, zero work is done by friction.

Q83. The K.E. of a body of mass 2kg and momentum of 2N is:

• A. 1 J✓
• B. 2 J
• C. 3 J
• D. 4 J

Explanation: By applying the formula P2/2m, we can find the KE, which will be 1J.

Q84. One wheel has a diameter of 30 inches and a second wheel has a diameter of 20 inches. The first wheel travels a certain distance revolution in 240 revolutions. In how many revolutions did the second wheel travel the same distance.

• A. 170
• B. 160
• C. 360✓
• D. 420

Explanation: We start off with finding the circumference of the first wheel which is 30 inches x 2 pi rads, giving us 60 pi inches. As the wheel made 240 revolutions, it travelled 60 pi inches per revolution; a total of 14400 pi inches. The second wheel, on the other hand, has a circumference of 40 pi thus it travels 40 pi per revolution. 14400 pi inches divided by 40 pi inches per revolution to give 360 revolutions.

Q85. One kilowatt - hour is equivalent to a factor _ in Joules.

• A. 1.2 x 105
• B. 1.2 x 106
• C. 3.6 x 105
• D. 3.6 x 106✓

Explanation: 1 kW =1000J/s 1 h =3600 s ∴ 1 kWh =1000 J/s×3600 s=36×10^5J = 3.6 X 106

Q86. The potential energy of a particle having a mass of 0.5 kg, moving along the x axis, is given by U= 2*x(x-3), where x = the distance moved by the particle. The speed of the particle will be maximum when it has moved a distance of:

• A. 1 m
• B. 1.5 m
• C. 2 m
• D. 3 m✓

Explanation: U = 2*3(3-3) = 0When potential energy is = 0, at that point all the potential energy would have been converted into kinetic energy. Thus when U = 0, K.E = max, and hence speed will be max.

Q87. Mark out the correct option

• A. The energy of any small part of a string remains constant in a travelling wave
• B. The energy of any small part of a string remains constant in standing wave✓
• C. The energies of all small parts of equal length are equal in a travelling wave
• D. The energies of all small parts of equal length are equal in a travelling wave

Explanation: In a standing / stationary wave, the energy within a loop stays constant

Q88. Which combination of up (u) and down (d) quarks forms a neutron?

• A. u u u
• B. u u d
• C. u d d✓
• D. d d

Explanation: combination of up (u) and down (d) quarks forms a neutron are u d d

Q89. SI unit of equivalent dose is?

• A. Gray
• B. Radiation
• C. Sievert✓
• D. Rem

Explanation: The SI unit of measure for equivalent dose is the "sievert", defined as one Joule per kg.

Q90. An object whose mass is 100 g starts from rest and moves with constant acceleration of 20 cm/s2. At the end of 8s its momentum in g cm / s is:

• A. 500
• B. 8000
• C. 16, 000✓
• D. 33, 000
• E. 64, 000

Explanation: Step 1: force = mass * acceleration force = 100 * 20 force = 2000 g cm / s2 Step 2: change in momentum = force * time change in momentum = 2000 * 8 change in momentum = 16000 g cm/s

Q91. A proton 'up' quark has a charge of:

• A. +2/3✓
• B. -1/3
• C. -2/3
• D. +1/3

Explanation: The two types of sub-atomic particles that you need to know are hadrons and leptons. Particles that are affected by the strong nuclear force are called hadrons, like protons and neutrons. Leptons are particles that are affected by the weak nuclear force, like electrons. Hadrons are made of quarks that can have one of 6 flavors. Two flavors found in a proton are up and down. The quark composition is such that the overall charge of the particle is maintained. In the case of a proton, that charge is +1. Proton: u u d The charge of 'u' is +2 / 3.

Q92. Motional e.m.f induced in a coil is dependent on?

• A. Magnetic field
• B. Orientation
• C. Length
• D. All of these✓

Explanation: The factors on which 'Motional emf' depends are nothing but, the 'magnetic field, velocity, and length of the rod'.

Q93. To generate force of repulsion both the charges must be

• A. Negative
• B. Positive
• C. May be positive or negative✓
• D. Cannot be determined

Explanation: For repulsion both the charges must be same, they can both be either positive or negative.

Q94. Identify the schematic representation of Fission Process from the following options?

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

Explanation: The answer to this question is A because first off we can rule out option D because it says energy conserved which is not true energy is always released in fission processes. Secondly, options B and C give an impression that both the fission fragments should also be identified which is not the case. They can be different as depicted by A.

Q95. Nuclear force is :

• A. spin independent
• B. both charge and spin independent
• C. spin dependent but charge independent✓
• D. charge dependent

Explanation: The nuclear force is nearly independent of whether the nucleons are neutrons or protons. This property is called charge independence. It depends on whether the spins of the nucleons are parallel or antiparallel, and has a noncentral or tensor component

Q96. Radiation can cause:

• A. leukemia
• B. radiation sickness
• C. skin cancer
• D. gene mutations
• E. all of the above✓

Explanation: All of the above are the potential consequences of radiation

Q97. The value of current in a short circuit is:

• A. Infinite✓
• B. Zero
• C. Minimum
• D. Maximum

Explanation: Option A is correct since, in a short circuit, there is no resistance to the flow of charges so, a large number of charges flow in a very short time. Thus, the current becomes infinite.Option B is incorrect since there is a flow of charges in a short circuit so, the current is not zero.Option C is incorrect since it states that the current will be very less, which is not true as the current will be large.Option D is incorrect as the maximum current can even occur with very low resistance. But when almost zero resistance is provided the current flow becomes infinite.

Q98. In amplitude modulation what remains the same:

• A. Frequency of the wave✓
• B. Amplitude of the wave
• C. Wavelength of the wave
• D. Intensity of waves

Explanation: It is a fact that amplitude changes in amplitude modulation whereas frequency changes.

Q99. Three resistors each having value 'R' are connected as shown in figure. What is the equivalent resistance between 'X' and 'Y'?

• A. 3R✓
• B. R
• C. R/3
• D. R3

Explanation: The resistors are connected in a series so the final resistance between x and y would be the sum of all resistances, R+R+R=3R

Q100. How many types of modulations are possible with sinusoidal carrier?

• A. Only one
• B. Two
• C. Three✓
• D. Four

Explanation: The carrier signal is a sine wave at the carrier frequency. The sine wave has three characteristics that can be altered. The term that may be varied is the carrier voltage Ec, the carrier frequency FC, and the carrier phase angle θ. So three forms of modulations are possible.

Q101. A neutron having mass equal to a proton (mp = 1.6 x 10-27 kg) is moving in a magnetic field of intensity 1.20 x 10-3 T with a speed of 2.0 x 107 ms-1 . What is the maximum force experienced by the neutron?

• A. 3.84 x 10-15 N
• B. 0✓
• C. 3.84 x 10-12 N
• D. 38.4 x 10-15 N

Explanation: Neutrons do not experience magnetic fields because it's a neutral particle, moving charged particles only experience the magnetic force

Q102. Newton's third law can be derived from:

• A. Newton's first law
• B. Newton's second law✓
• C. Both Options A and B are correct
• D. They are unrelated

Explanation: Newton's second law gives the definition and mathematical expression of force. By using the expression of force, we can derive Newton's third law. Newton's third law of motion states that for every action, there is an equal and opposite reaction. This means that if object A exerts a force on object B, object B exerts an equal and opposite force on object A. The third law can be derived from the second law by considering the interaction between two objects. When object A exerts a force on object B (according to the second law), object B simultaneously exerts an equal and opposite force on object A. This satisfies the principle of conservation of momentum and leads to Newton's third law. So, the correct answer is option B.