Fmdc 2014 — Solved Past Paper with Answers

Q1. My dog happily _ itself under the table and chewed contentedly at a piece of bone.

• A. Eclipsed
• B. Elucidated
• C. Exhumed
• D. Ensconced✓

Explanation: “Ensconced” means to settle yourself comfortably in a safe, cosy, or hidden place.A dog slipping under a table, getting comfortable, and chewing a bone quietly fits this meaning perfectly. The word describes both the movement and the comfortable, secure position the dog takes.

Q2. Which word is closest in meaning of "ASTOUND"?

• A. Shock✓
• B. Confer
• C. Condescend
• D. Strengthen

Explanation: The word ‘Astound’ means to shock or surprise someone. So Option A is the right option.

Q3. Which contains an adjective?

• A. Old man✓
• B. On Tuesday
• C. She said
• D. And you
• E. Afternoon

Explanation: A. Old is an adjective here as it modifies the noun ‘man’.B. On Tuesday is an example of adverb of time.C. She said is an example of an intransitive verb.D. And you is just a sentence.E. Afternoon is a noun.

Q4. Crystal vase breaks easily, _ handle it with care.

• A. So that
• B. So much
• C. So✓
• D. So well

Explanation: Option C is the right option. The above sentence gives us an idea about how to stop the vase from breaking. It cautions us to handle it with care. ‘So’ fits here.

Q5. Choose the correct option. The Police do not understand how the thieves _ the house.

• A. Got into✓
• B. Got in
• C. Get into
• D. Get in

Explanation: ‘Got into’ the house is the correct answer. The sentence involves a phrasal verb ‘got into’ which means enter into the house.

Q6. Which of the following words is closes to the meaning of "BEHOLD"?

• A. See✓
• B. Touch
• C. Hear
• D. Smell

Explanation: The word behold means to look or see something. So, Option A is the right answer.

Q7. Identify the word or phrase that needs to be changed for the sentence to be correct:Ali finds it difficult to put his idea into words.

• A. Finds
• B. Difficult
• C. To put
• D. Into
• E. No error✓

Explanation: The sentence "Ali finds it difficult to put his idea into words" is grammatically correct. Each part of speech is used appropriately: "finds" is a suitable present tense verb, "difficult" is an accurate adjective, "to put" is correctly used as an infinitive phrase to indicate the action, and "into" is the right preposition to show the direction of the action. Therefore, the correct answer is "No error." All other options describe parts of the sentence that are correctly used.

Q8. Identify the word or phrase that needs to be changed for the sentence to be correct:Owing to the flooded condition of roads, most of the people were unable to get to the offices.

• A. Owing
• B. Flooded
• C. Unable
• D. Get to
• E. No error✓

Explanation: The sentence is already correct and does not require any changes. It is grammatically accurate and effectively conveys the intended meaning.

Q9. Identify the word or phrase that needs to be changed for the sentence to be correct:Sharks differ from other fish in that their skeleton are made of cartilage instead bone.

• A. Differ
• B. Fish
• C. Are made✓
• D. Instead
• E. No error

Explanation: The correct answer is Option C: 'Are made'. The term 'skeleton' is singular, so it requires the singular verb 'is made' rather than the plural 'are made'. The other options are grammatically correct: 'differ' is the appropriate verb for showing differences, 'fish' is correctly used in its plural form, and 'instead' properly indicates a contrast. Thus, the sentence should read: 'Sharks differ from other fish in that their skeleton is made of cartilage instead of bone.'

Q10. Choose the correct option. It tripped _the cat and fell downstairs.

• A. Over✓
• B. On
• C. Onto
• D. In

Explanation: The correct answer is 'Over' because it appropriately describes the action of tripping across or above the cat, leading to a fall downstairs. 'On' and 'Onto' suggest direct contact with or movement onto the cat, which does not logically fit the sentence. 'In' is used to describe being inside something, which is not relevant to the scenario described.

Q11. The _left their home land to another country in the hope of securing a better future for their families.

• A. Emigrants✓
• B. Immigrants
• C. Migrants
• D. Strollers

Explanation: A. Emigrants are people who leave their homeland and go to another country. Option A is right.B. Immigrants are the people that are taken into a new country in the hope of securing a better future. B is wrong because when we talk about people who leave their homeland, they are emigrants, not immigrants.C. Migrants move from one place to another for a better person. It is not necessary for them to leave their homeland for another country. Hence Option C is wrong.D. Strollers are people taking a leisurely walk. Option D is totally wrong.

Q12. Hundreds of years old palace could not withstand the _ of heavy rains.

• A. Aftermath
• B. Havoc✓
• C. Annoyance
• D. Massacre

Explanation: When we refer to natural disasters, we use the word ‘havoc’ to describe their adverse destruction. Aftermath doesn’t fit here because aftermath just means the consequences of an unpleasant event. Option B is the most suitable option here when compared with the rest of the options.

Q13. Choose the correct spelling:

• A. Amatuer
• B. Amature
• C. Amateur✓
• D. Ameteur

Explanation: The correct spelling is Amateur, which refers to someone who engages in a pursuit for pleasure rather than for financial benefit. This word is borrowed from French, where the ending 'ateur' is a common suffix. The other options, such as 'Amatuer', 'Amature', and 'Ameteur', are incorrect as they either reorder the vowels incorrectly or alter the word's structure, diverging from the original spelling.

Q14. RITUAL means:

• A. Custom✓
• B. Original
• C. Religion
• D. Routine

Explanation: Ritual means a custom or a tradition of a civilization that has been going on for a while. It is a religious or solemn ceremony consisting of a series of actions performed according to a prescribed order.

Q15. Choose the correct option. He complains _ headache.

• A. At
• B. From
• C. Of✓
• D. To

Explanation: Option C is grammatically correct. At, from, and to are all wrong. He complains of something which is in this case a headache.

Q16. "He is appreciated for being ambidextrous ." The underlined word means:

• A. Active and Skillful
• B. Uses skills and wisdom
• C. Uses both hands with same skills✓
• D. Remains to the point

Explanation: Ambidextrous means using both hands with equal ease or dexterity.Examples:- an ambidextrous pitcher- Guatelli says the master was ambidextrous, that he sketched with his right hand while he wrote with his left simultaneously.

Q17. My friend has a fine _ of old stamps.

• A. Group
• B. Bundle
• C. Band
• D. Collection✓

Explanation: A "collection" is a set of items gathered and kept together, often because of their rarity, beauty, or sentimental value. In this case, your friend has a fine collection of old stamps, indicating a curated and possibly valuable assembly of stamps.

Q18. The synonym for the word DISSIPATED is:

• A. Degenerate✓
• B. Pleased
• C. Inundated
• D. Encouraged
• E. Planned

Explanation: The word 'dissipated' often refers to a lifestyle characterized by overindulgence and a lack of restraint, similar to 'degenerate,' which implies moral decline.

Q19. The synonym for the word COUNTENANCE is:

• A. Procure
• B. Insist
• C. Approve of✓
• D. Forego

Explanation: The correct answer is Option C: 'Approve of'. The term 'countenance' can refer to supporting or accepting something, which aligns with 'approve of'.

Q20. At which side does digestion of starches begin?

• A. The mouth✓
• B. The stomach
• C. The small intestine
• D. The large intestine
• E. The esophagus

Explanation: The correct answer is the mouth. Digestion of starches begins in the oral cavity, where Salivary Amylase is secreted by the salivary glands to initiate the breakdown of starch into maltose and other simpler sugars. This process does not begin in the stomach, small intestine, large intestine, or esophagus. The stomach primarily digests proteins, the small intestine continues and completes the digestion of carbohydrates, and the large intestine focuses on water absorption. The esophagus is solely a passage for food.

Q21. What is the part labelled as 5 in the following diagram?

• A. Produces bile
• B. Stores bile✓
• C. Secretes lipase
• D. Secretes bicarbonate
• E. Secretes HCI

Explanation: The correct answer is that the gall bladder stores bile. Bile is produced by the liver and stored in the gall bladder until it is needed for digestion. The gall bladder does not produce or secrete enzymes like lipase or bicarbonates, nor does it secrete hydrochloric acid, which are the functions of the pancreas and stomach, respectively.

Q22. Which structure is primarily responsible for water absorption during digestion?

• A. Liver
• B. Pancreas
• C. Esophagus
• D. Large Intestine✓
• E. Trachea

Explanation: The correct answer is the large intestine, which is the primary site for water absorption during digestion. It absorbs water and salts from the material that has not been digested as food, and it compacts waste into feces. The liver, pancreas, esophagus, and trachea have different functions. The liver is involved in bile production and detoxification, the pancreas secretes digestive enzymes and hormones, the esophagus is a food conduit, and the trachea is part of the respiratory system.

Q23. The diagram summaries the pathway of glucose break-down:Which two steps result in a net increase of ATP?

• A. 1 and 3
• B. 1 and 4
• C. 2 and 4
• D. 2 and 5✓
• E. 3 and 3

Explanation: Steps 2 and 5 are the correct answers because they both result in a net increase of ATP. Step 2 relates to glycolysis, where 4 ATPs are produced, leading to a net gain of 2 ATPs after accounting for the ATPs used. Step 5 refers to the citric acid cycle, where additional ATP is generated through substrate-level phosphorylation and oxidative phosphorylation. Other steps either do not result in ATP production or are not directly involved in energy yield.

Q24. Which one of the following enables the mammalian kidney to regulate water reabsorption during states of dehydration?

• A. The cells of the tubules detect the osmotic pressure of the blood
• B. Water is extracted from the glomerular filtrate in the proximal tubule
• C. The kidney produces hyptonic urine
• D. Hormones increase the permeability of the collecting ducts✓
• E. A low solute concentration is maintained around the collecting ducts

Explanation: Option D is correct.Water excretion by the kidney is regulated by the peptide hormone vasopressin. Vasopressin increases the water permeability of the renal collecting duct cells, allowing more water to be reabsorbed from collecting duct urine to blood.

Q25. A drug reduces mitochondrial activity in nephrons of the kidney. Which chemical will be present in increased amounts in the urine?

• A. Ammonia
• B. Glucose✓
• C. Hydrogen bicarbonate
• D. Urea

Explanation: This happens because in mitochondria aerobic respiration occurs(breakdown of food in presence of oxygen)The food is glucose.Aerobic respiration:Glucose+O2=CO2 + ATPSo if the mitochondrial activity is reduced then glucose will not be used and will be excreted out through urine.

Q26. Where, in the nephron, is most glucose reabsorbed?

• A. In the ascending loop of henle
• B. In the descending loop of henle
• C. In the proximal (first) convoluted tubule✓
• D. In the distal (second) convoluted tubule

Explanation: Most of the glucose entering the tubular system is reabsorbed along the nephron segments, primarily in the proximal tubule, such that urine is almost free of glucose. This is different in diabetes, where the filtered glucose exceeds the transport capacity of the tubular system for glucose and glucosuria occurs.

Q27. Consider the following statements about biological communities.(I) Their members share a common gene pool.(II) The community remains stable even though some physical aspect of the environment may undergo change.(III) They passes predictable kinds of species of predictable proportions.(IV) Interactions between their members are more frequent within the community than between their members and those of neighboring communities.Which two of the above statements apply to all stable biological communities?

• A. I band II
• B. II and III
• C. I band III
• D. III and IV✓
• E. II and IV

Explanation: A. I is not right since a community involves different populations which may have different gene pool.B. II is also not right since different populations may interact in different ways with each other and disturb the genetic pool and stability.C. III is right and is a fact.D. IV is also right since intra-specific interactions are more common than inter-specific interactions in communities.Hence III and IV are the right options (Option D).

Q28. The spinal cord serves as the center of:

• A. Subconscious thought
• B. Reflex actions✓
• C. Habits
• D. Tropism

Explanation: It is the processing unit for reflex actions because all nerves from various parts of the body meet at the spinal cord before reaching the brain.

Q29. The most abundant substance in protoplasm is:

• A. Protein
• B. Fat
• C. Carbohydrate
• D. Water✓
• E. Minerals

Explanation: Protoplasm is a mixture of small molecules such as ions, monosaccharides, amino acids, and macromolecules such as proteins, polysaccharides, lipids, etc.On the average protoplasm contains 84 percent water. Most of the water is present in free unbounded form and provides a medium for metabolic reactions occurring in a cell.

Q30. The placenta releases all of the following hormones EXCEPT:

• A. Progesterone
• B. LH (Luteinizing Hormone)✓
• C. HCG (Human Chorionic Gonadotropin)
• D. Estrogen
• E. Minerals

Explanation: The correct answer is LH (Luteinizing Hormone). LH is produced by the pituitary gland and is not released by the placenta. It plays a crucial role in the menstrual cycle and ovulation process. The other hormones listed—progesterone, HCG, and estrogen—are produced by the placenta during pregnancy to support the developing fetus and maintain the pregnancy. While the placenta does not release minerals directly, it is involved in nutrient transfer from the mother to the fetus.

Q31. All of the following organs produce hormones involved in the reproductive cycle except the:

• A. Testes
• B. Pituitary Gland
• C. Pancreas✓
• D. Ovary
• E. Uterus

Explanation: The pancreas is primarily involved in metabolic functions, specifically the regulation of blood sugar levels through hormones like insulin and glucagon. It does not play a role in the reproductive cycle, unlike the testes, pituitary gland, ovaries, and uterus, all of which produce hormones critical to reproductive processes. Thus, the pancreas does not contribute to hormone production for reproduction, making it the correct answer.

Q32. In human female FSH regulates the concentration of:

• A. A: Control
• B. B: Estrogen✓
• C. C: Cortisol
• D. D: Aldosterone
• E. E: None of the above

Explanation: Follicle stimulating hormone (FSH) is crucial in managing the female reproductive system. It is produced by the pituitary gland and influences the menstrual cycle by promoting the growth of ovarian follicles. FSH specifically stimulates the granulosa cells in these follicles to secrete estrogen, which is essential for ovulation and overall reproductive health. This distinguishes estrogen from other hormones like cortisol and aldosterone, which are regulated by different mechanisms and serve different purposes in the body.

Q33. The Reduction-division occurs during the process of:

• A. Cleavage
• B. Differentiation
• C. Fertilization
• D. Meiosis✓
• E. Parthenogenesis

Explanation: Meiosis is a reduction division because Meiosis I separates homologous chromosomes, reducing the number of chromosomes in the resulting cells by half. A diploid (two sets of chromosomes) parent cell becomes two haploid (one set of chromosomes) cells. This reduction in chromosome number is essential for the formation of gametes (sperm and eggs), ensuring that when fertilization occurs, the resulting offspring has the correct diploid chromosome number.

Q34. The muscles attached to the bones are

• A. Voluntary and smooth
• B. Involuntary and smooth
• C. Voluntary and striated✓
• D. Involuntary and striated
• E. Smooth and striated

Explanation: Voluntary muscles are under conscious control, allowing us to move our bodies intentionally. Striated muscles have a striped appearance under a microscope due to the organization of their contractile proteins, giving them the name "striated." These muscles are also known as skeletal muscles and are responsible for body movements.

Q35. Which of the following statement regarding the periosteum is INCORRECT:

• A. The periosteum serves as the site of attachment of bone to muscle
• B. Cells of the periosteum differentiate into osteoblasts.✓
• C. The periosteum is a fibrous sheath that surrounds long bones
• D. None of the above

Explanation: Your periosteum helps your bones grow and develop.Osteoblasts originate from immature mesenchymal stem cells, which can also differentiate and give rise to chondrocytes. Mesenchymal stem cells undergo several transcription steps to form mature osteoblast cells.

Q36. The absorption and use of calcium are regulated by:

• A. Parathormone✓
• B. Adrenaline
• C. Thyroxin
• D. Thiamin
• E. Prolactin

Explanation: Circulating parathyroid hormone targets the distal convoluted tubule and collecting duct, directly increasing calcium reabsorption.

Q37. The most correct statement about muscle contraction is:

• A. Actin itself moves to shorten the muscle
• B. Cross bridges formed between myofibril molecules are made of G-actin
• C. Contraction of myosin molecules directly causes muscle contraction
• D. Ca²⁺ is necessary for the binding of cross bridges✓

Explanation: Calcium ions (Ca²⁺) are essential for muscle contraction. When a muscle is stimulated to contract, calcium ions are released from the sarcoplasmic reticulum. These ions bind to troponin, a regulatory protein on the actin filaments. This binding causes a change in the shape of the troponin-tropomyosin complex, exposing binding sites on the actin for myosin heads. This exposure allows myosin to form cross bridges with actin, initiating the contractile process.Option A is incorrect because the actin filaments do not independently move to shorten the muscle; they are pulled by myosin heads. Option B is incorrect because cross bridges are not formed from G-actin but involve myosin heads binding to actin. Option C is incorrect because it is the action of myosin heads, not the contraction of myosin molecules, that causes muscle contraction.

Q38. On a very cold day, a man waits for over an hour at the bus stop. Which of the following structures helps his body set and maintain a normal temperature?

• A. Hypothalamus✓
• B. Kidneys
• C. Posterior pituitary
• D. Brainstem

Explanation: On a cold day, the body must maintain a stable core temperature to function properly. The hypothalamus is crucial for this task as it senses changes in body temperature and triggers responses like shivering and vasoconstriction to conserve heat. This makes the hypothalamus the correct answer. In contrast, the kidneys focus on fluid balance, the posterior pituitary on hormone release, and the brainstem on other automatic functions, none of which directly involve temperature regulation.

Q39. Energy can be made available to the body in the following ways:(I) Conversion of surplus amino acids and glycerol to blood glucose and the mobilization of fat deposits which pass to the tissues for oxidation.(II) Breakdown of liver and muscle glycogen to form glucose.(III)Breakdown of tissue proteins to release amino acids which are then converted into glucose.In which order does the body draw on potential energy when it is being starved of food?

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

Explanation: Option C (II, I, and III) is correct because the conversion of surplus amino acids and glycerol to blood glucose and the mobilization of fat deposits (I) occurs after the breakdown of liver and muscle glycogen (II). Therefore, the correct order should be II, I and III.

Q40. The nucleus contains all of the following structures except:

• A. Mitochondria✓
• B. Chromatin
• C. Genes
• D. Nucleolus
• E. Nuclear membrane

Explanation: Nucleus contains nuclear envelope, nuclear lamina, nucleolus, chromosomes, nucleoplasm. Numerous Mitochondria are present in cell but not in nucleus.

Q41. Which of the following choices INCORRECTLY pairs a digestive enzyme with its secretion?

• A. Pancreatic amylase -> pancreas
• B. Aminopeptidase -> stomach✓
• C. Enterokinase -> intestinal glands
• D. Maltase -> intestinal glands

Explanation: Aminopeptidases catalyze the cleavage of amino acids from the amino terminus of protein or peptide substrates.It is produced and secreted by glands of the small intestine.

Q42. The division of biology that deals with classification is:

• A. Cytology
• B. Histology
• C. Botany
• D. Morphology
• E. Taxonomy✓

Explanation: The correct answer is Taxonomy. Taxonomy is the branch of biology concerned with the classification, naming, and organization of living organisms into hierarchical structures such as species, genus, and family. This systematic approach allows scientists to identify and communicate about organisms effectively.Cytology focuses on cells, Histology on tissues, Botany on plants, and Morphology on the form and structure of organisms, none of which directly involve the classification of all living organisms. Thus, they do not fulfill the role of taxonomy.

Q43. All the following are organelles EXCEPT the:

• A. Endoplasmic reticulum
• B. Mitochondria
• C. Ribosomes
• D. Golgi complex
• E. Ultracentrifuge✓

Explanation: Ultra centrifuge is not an organelle; it is a very fast centrifuge used to precipitate large biological molecules from solution or separate them by their different rates of sedimentation.

Q44. The diagram shows a section through a kidney and associated blood vessels.In which area is there the greatest movement of fluid from the blood through the wall of blood vessels?

• A. A
• B. B
• C. C
• D. D
• E. E✓

Explanation: E is the renal cortex. It has the greatest blood flow in the following options. The cortex requires about 80% of blood flow to achieve its excretory and regulatory functions, and the outer medulla receives 15%. The inner medulla receives a small percent of blood flow; a higher flow would wash out solutes responsible for the high tonicity of the inner medulla.

Q45. Which function is not carried out by the mammalian kidney?

• A. Removal of bile pigments from the body✓
• B. Removal of excess mineral salts from the body
• C. Maintenance of a constant osmotic pressure of the blood
• D. Maintenance of a constant pH of the blood

Explanation: Bile is removed by the bacteria in Small intestine. Conjugated bilirubin is secreted into the bile canaliculus as part of bile and thus delivered to the small intestine. Bacteria in the intestinal lumen metabolize bilirubin to a series of other compounds which are ultimately eliminated either in feces or, after reabsorption, in urine. Thus, removal of bile is not mainly carried about the kidney. All the other processes are in fact carried out by the kidney.

Q46. According to the Hardy-Weinberg principle, the gene pool may remain stable if there are:

• A. Random mating✓
• B. Many mutations
• C. Frequent migrations
• D. Selected mating
• E. Random mutations

Explanation: Conditions for hardy-Weinberg equilibrium are as follows: No mutations (Crosses out E and B). No natural selection. Random Mating (Crosses out D). No immigration or emigration (Crosses out C).

Q47. Genes P, Q, R, and S occur on the same chromosome.Investigation of a large population produced the following cross-over values between pairs of genes.P and R 34% P and Q 59% R and S 12% S and Q 37% Which of the following sequences represents the sequence of genes on the chromosome?

• A. PRSQ
• B. PSRQ✓
• C. QSPR
• D. RQSP
• E. SPRQ

Explanation: The correct sequence of genes on the chromosome is PSRQ. This arrangement makes sense given the crossover values provided:The low crossover value of 12% between R and S indicates they are closely linked, which is consistent with having them next to each other in this sequence.The higher crossover value of 59% between P and Q suggests they are further apart on the chromosome, which is also supported in this arrangement.The other options (PRSQ, QSPR, RQSP, SPRQ) do not appropriately reflect the crossover data, leading to contradictions with the provided percentages.

Q48. Which of the following hind of atom do not occur in carbohydrates?

• A. Carbon
• B. Hydrogen
• C. Nitrogen✓
• D. Oxygen

Explanation: Nitrogen is not present in Carbohydrates. It is present in proteins due to the presence of amino group (NH2).

Q49. The diagram is taken from an electron micro graph of a cell, name the organelle labeled D:

• A. Nucleus
• B. Lysosome
• C. Golgi complex
• D. Mitochondrion✓

Explanation: Organelle D is identified as a mitochondrion because of its distinctive rod shape, which is characteristic of mitochondria. Mitochondria are crucial for energy production in the cell. In contrast, the nucleus is usually larger and centrally located, lysosomes are spherical, and the Golgi complex is a network of flattened sacs, none of which match the description of organelle D.

Q50. Endoplasmic reticulum of the following organic compounds, the one that represents a protein is:

• A. C12H22O11
• B. C6H12O6
• C. C17H14COOH
• D. (C6H10O5)11
• E. C108H130O180S4✓

Explanation: Option E: C108H130O180S4 is most indicative of a protein due to the presence of sulfur atoms, which are typically found in certain amino acids that make up proteins. The other options are not proteins: Option A is a disaccharide carbohydrate, often found in sugars like sucrose.Option B is a monosaccharide, a simple sugar like glucose.Option C is a fatty acid, which forms part of lipids.Option D is a polysaccharide, a complex carbohydrate often found in starches.

Q51. In which of the following is the organic compound COOH (carboxyl) group found? (I) Carbohydrate (II) Lipid (III) Protein

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

Explanation: Carboxyl groups are commonly found in amino acids, fatty acids, and other biomolecules. Whereas carbohydrates only contain atoms of carbon hydrogen and oxygen they don't have any functional group.

Q52. Part of the periodic table is shown. The letters are not the symbols of the elements.Which statement is correct?

• A. V is more reactive than Y
• B. W has more metallic character than V
• C. Y has a lower melting point than V✓
• D. Z is more reactive than X

Explanation: A. Reactivity for metals increases down the group so V is less reactive than Y which is below V.B. Metallic character decreases as we go from left to right so W has less metallic character than V.C. Melting point for Group I-IV increases across the period and decreases down the group. Y being below V will have a lower melting point. Hence Option C is correct.D. Reactivity decreases down the group for halogens and nonmetals.

Q53. The bar chart shows the period of elements from lithium to neon.Which property of these elements is shown on the chart?

• A. The number of electrons used in bonding✓
• B. The number of electron shells
• C. The atomic number
• D. The atomic mass

Explanation: The correct answer is Option A: 'The number of electrons used in bonding'. As you move across the period from lithium to neon, the number of valence electrons increases from 1 in lithium to 8 in neon. This trend reflects how these elements can form bonds. Noble gases like neon do not typically form bonds because they have a full valence shell. Options B, C, and D do not accurately describe the trend shown in the chart. The number of electron shells (Option B) is constant across the period, the atomic number (Option C) does increase but does not specifically relate to bonding, and atomic mass (Option D) is not the focus of the chart as it pertains to bonding properties.

Q54. a- helices are secondary structures characterized by:

• A. Intramolecular hydrogen bonds✓
• B. Disulfide bonds
• C. A rippled effect
• D. Hydrophobic interactions

Explanation: A. a-helix and beta pleated sheets have hydrogen bonding so Option A is correct.B. Disulfide bonds is present in tertiary structure of proteins.C. Rippled effect has nothing to do with the structure of proteins.D. Hydrophobic interactions are present in quaternary structure of proteins.

Q55. A metal sulfate contains 9.87% of M. This sulfate is isomorphous with ZnSO4,.7H2O. Determine the atomic weight of the metal M.

• A. 24.31✓
• B. 34.31
• C. 25.25
• D. 44.41
• E. 30.75

Explanation: To determine the atomic weight of the metal M, first recognize that the sulfate compound is isomorphous with ZnSO4.7H2O, meaning it has a similar structure, MSO4.7H2O. The molecular mass of MSO4.7H2O can be expressed as x + 32 (S) + 64 (4O) + 126 (7H2O) = 222 + x.Given that the metal M constitutes 9.87% of the total mass, set up the equation: (9.87/100) * (222 + x) = x. Solving this yields x = 24.31, indicating that the metal is magnesium.Other options do not satisfy this equation and percentage relationship, leading them to be incorrect.

Q56. 100 c.c of oxygen is collected over water at 23°C and 800mm pressure. If vapour pressure of water vapours at 23°C is 21.00mm, then calculate volume of the gas at NTP.

• A. 100 c.c
• B. 94.53 c.c✓
• C. 150 c.c
• D. 90.0 c.c

Explanation: To find the volume of oxygen at NTP, we use the formula P1V1/T1 = P2V2/T2, adjusting for water vapor pressure:1. Subtract the vapor pressure of water from the total pressure to get the pressure of dry oxygen: P1 = 800mm - 21mm = 779mm.2. Substitute the known values: P1 = 779mm, V1 = 100 c.c, T1 = 296K; P2 = 760mm, T2 = 273K.3. Rearrange the formula to solve for V2: V2 = (P1 * V1 * T2) / (P2 * T1).4. Substitute and calculate: V2 = (779 * 100 * 273) / (760 * 296) ≈ 94.53 c.c.Therefore, the correct volume at NTP is 94.53 c.c. Options A, C, and D result from errors in calculation or misunderstanding of the conditions.

Q57. Y g of the non-volatile substance (molecular mass M) is dissolved in 250g of benzene. If Kb is the molal elevation constant, the value of AT us given by:

• A. 4M/Kb
• B. 4Kb.Y/M✓
• C. Kb.Y/4M
• D. Kb Y/M

Explanation: The elevation in boiling point (ΔT) for a solution is calculated using the formula ΔT = (Kb × m), where m is the molality of the solution. In this case, the molality is given by (1000 × Y) / (250 × M), since the mass of the solvent is 250g. Substituting into the formula, we simplify to ΔT = (1000 × Kb × Y) / (250 × M) = 4KbY/M. Option B correctly represents this relationship. The other options incorrectly manipulate the formula, leading to incorrect expressions for the elevation in boiling point.

Q58. A mixture of ethanol and propanol has vapour pressure of 290mm at 29oC. If mole fraction of ethanol is 0.65, then what will be its vapour pressure if vapour pressure of pure propanol is 210mm?

• A. 333.1 mm✓
• B. 441.5 mm
• C. 890.2 mm
• D. None of the above

Explanation: Vapour pressure of ethanol (P₁) = 290 mm, mole fraction of ethanol (X₁) = 0.65, vapour pressure of propanol (P₂) = 210 mm.Using Raoult's law: P₁ = X₁ * P°₁ and P₂ = X₂ * P°₂, where P°₁ and P°₂ are the vapour pressures of pure ethanol and propanol, respectively.Since the mixture contains only ethanol and propanol: X₁ + X₂ = 1.Solving for X₂: X₂ = 1 - X₁ = 1 - 0.65 = 0.35.Now, calculate P₁ using the formula: P₁ = X₁ * P°₁ = 0.65 * P°₁.Similarly, calculate P₂ using the formula: P₂ = X₂ * P°₂ = 0.35 * 210 mm.Finally, calculate the total vapour pressure of the mixture: P_total = P₁ + P₂ = (0.65 * P°₁) + (0.35 * 210 mm) = 333.1 mm.

Q59. At 25°C, the equilibirum constant K1 and K2 in the two reactions are 2NH3⇌N2 + 3H2 and 1/2 N2 +3/2H2=NH3 respectively.K1 and K2 are related as:

• A. Kl – K2
• B. Kl = 1/ K22✓
• C. K2 = K1
• D. K2= 1/Kl

Explanation: Option B is correct.2NH3 = N2+3H2 ; K1Reverse the reactioni.e. 3H2+N2 = 2NH3 ; 1/K1Multiply above reaction by 1/2Required reaction is1/2N2+3/3H2 = NH ; (1/K1)½Therefore, K2 = (1/K1)½

Q60. For the reaction N2 + O2 2NO, the value of K is 0.0842 at 3500 K. Calculate the fraction of equilibrium mixture of N2 and O2 converted into NO.

• A. 15.0%
• B. 16.3%
• C. 16.5%
• D. 16.9%✓

Explanation: To find the fraction of N2 and O2 converted into NO at equilibrium, we define x as the fraction converted. The equilibrium concentrations can be expressed as [NO] = 2x, [N2] = (1 - x), and [O2] = (1 - x). Using the equilibrium constant expression K = (2x)^2 / ((1 - x) * (1 - x)), we substitute K = 0.0842 and simplify to form a quadratic equation: 4.0842x^2 - 0.1684x - 0.0842 = 0. Solving this equation gives x ≈ 0.169, which translates to approximately 16.9%. Therefore, Option D is correct. Other options result from calculation errors or incomplete solutions, leading to incorrect fractions of conversion.

Q61. Chlorine in Vinyl chloride is not very reactive because

• A. C−Cl bond develops partial double bonds✓
• B. Of resonance
• C. Sp2 hybridized carbon has more acidic character than sp3 hybridized carbon
• D. All of the above

Explanation: The chlorine in vinyl chloride is not very reactive because the C−Cl bond develops partial double bonds due to the pi bond formed between the sp2 hybridized carbon and the chlorine atom. This partial double bond character reduces the reactivity of the C−Cl bond.

Q62. One of the isomers of C6H12(A) has chiral carbon but on hydrogenation it losses chirality. A is:

• A. 2-Methyl-2-pentene
• B. 2,3-Dimethyl-2-butene
• C. 3-methyl-1-pentene✓
• D. 3,3-Dimethyl 1-butene

Explanation: The compound C is 3-methyl-1-pentene. It is shown in the option C. It has molecular formula C6​H12​ and is optically active. On catalytic hydrogenation, it gives 3-methylpentane having molecular formula C6​H14​ which is optically inactive.

Q63. An equimolar quantities of ethanol and methanol are heated with conc.H2SO4. The product formed is?

• A. CH3OCH3
• B. C2H5OCH3
• C. C2H5OC2H5
• D. All of the above✓

Explanation: Option D is correct as they represent the products that can be formed when equimolar quantities of ethanol and methanol are heated with concentrated sulfuric acid.

Q64. Which one of the following phenol is more soluble in ag.NaHC03?

• A. 2, 4-Dihydroxy acetophenone
• B. 2, 4, 6-Tricyano phenol✓
• C. 3, 4-Dicyano phenol
• D. p-cyano phenol

Explanation: Since there are 3 cyano-groups attached to the phenol in Option B compared with C and D, it will be more soluble in NaHCO3. Electron donating groups increase the acidity of the phenol. A phenol with 3 cyano groups will be more acidic than a phenol with two OH- groups. Therefore, B is the most acidic and hence the most soluble in base.

Q65. A water soluble compound of molecular formula C3 H6O gives yellow crystalline solid on heating with I2, and Na2CO3. The compound is:

• A. CH3CH2CHO
• B. CH20CH = CH2
• C. CH3COCH3✓
• D. CH2 = CHCH2OH

Explanation: The correct answer is Option C: CH3COCH3 (acetone). This compound is water-soluble and matches the molecular formula C3H6O. Acetone contains a methyl ketone group, which reacts with I2 and Na2CO3 in the haloform reaction to produce iodoform (CHI3), a yellow crystalline solid. Option A (CH3CH2CHO) is an aldehyde and does not have the methyl ketone group required for the iodoform test. Option B (CH20CH = CH2) lacks the necessary functional group for this reaction. Option D (CH2 = CHCH2OH) is a primary alcohol, which also does not give a positive iodoform test.

Q66. Arrange the following compounds in order of increasing reactivity towards the addition of HCN.Acetone (I), acetaldehyde (II), methyl t-butyl ketone (III), di-t-butvl ketone (IV):

• A. IV <I <II <III
• B. I < II < III < IV
• C. IV < III < I < II✓
• D. II< I < IV < III

Explanation: The more the bulky groups attached to the carbonyl atom, the less the reactivity becomes.- Acetone has two bulky groups attached it.- Acetaldehyde has one bulky group attached to it.- Methyl t-butyl ketone has a tertiary butyl and methyl group attached to it which make it less reactive.- Di-t-butyl ketone has two tertiary butyl groups attached to it which make it the least reactive out of all the options.So the correct order will be IV<III<I<II

Q67. The reaction CH3COOAg + Br2 CH3Br + CO2 + AgBr is known as:

• A. Reformat sky reaction
• B. Huns dicker reaction✓
• C. Decarboxylation
• D. Hell-Volhard-Zelinsky reaction

Explanation: Therefore, the correct option must be B (Hunsdicker reaction) as it accurately describes the reaction where a silver carboxylate (CH3COOAg) reacts with bromine (Br2) to form methyl bromide (CH3Br), carbon dioxide (CO2), and silver bromide (AgBr).

Q68. Butyrolactone (ester) does not react with:

• A. NH3
• B. UAIH4
• C. EtOH.H
• D. NaBH4 / EtOH✓

Explanation: The correct option is D (NaBH4/EtOH), as sodium borohydride (NaBH4) in ethanol (EtOH) is not a strong enough reducing agent to reduce esters. It is typically used for the reduction of aldehydes and ketones but does not typically react with esters.

Q69. Electric cookers have a coating that protects them against fire:

• A. Heavy lead
• B. Magnesium oxide✓
• C. Zinc oxide
• D. Sodium sulphate

Explanation: Magnesium Oxide (MgO) has a high melting point that makes it so that it doesn't burn under low pressure and high temperature.

Q70. Macromolecules are of _ types.

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

Explanation: Macromolecules are large, complex molecules that are critical to various biological functions and structures. There are four primary types of macromolecules:Carbohydrates: These serve as energy sources and structural components in cells.Proteins: These molecules perform a wide range of functions, including catalyzing reactions (enzymes), providing structural support, and regulating processes.Lipids: These are involved in energy storage, cell membrane structure, and signaling.Nucleic Acids: These molecules, such as DNA and RNA, are responsible for storing and transmitting genetic information.Options for three, five, six, and seven types are incorrect because they do not align with the widely accepted classification of these four essential macromolecules in biological systems.

Q71. The long chains of Amino Acids are called:

• A. Oils
• B. Polypeptides✓
• C. Monopeptides
• D. Proteins

Explanation: Polypeptides are the long chains/polymerized chains of amino acids. Option A and C are clearly wrong. One could argue about option D but proteins are chains of polypeptides. Option B is the most suitable answer for this.

Q72. Select the correct general formula for carbohydrates:

• A. C2nHnO2n
• B. Cn(H2O)2n
• C. Cn(H2O)n✓
• D. CnH3nO2n
• E. Hn(C2O)n

Explanation: The term carbohydrate means "hydrate of carbon." Many common carbohydrates have the empirical formula CH2O, which can be generalized to Cn(H2O)n. This formula shows that the ratio of hydrogen to oxygen atoms is 2:1, the same as in water.

Q73. Lipids are generally defined in terms of:

• A. Solubility✓
• B. Structure
• C. Molarity
• D. All of the above

Explanation: Lipids are defined by Solubility and Intermolecular Forces. lipids are a class of naturally occurring molecules that are soluble in nonpolar organic solvents, and are not soluble in water.

Q74. As a result of increased CO2 in the atmosphere, oceans will become more:

• A. Alkaline
• B. Acidic✓
• C. Saline
• D. Cooler

Explanation: Because of human-driven increased levels of carbon dioxide in the atmosphere, there is more CO2 dissolving into the ocean. The ocean's average pH is now around 8.1 , which is basic (or alkaline), but as the ocean continues to absorb more CO2, the pH decreases and the ocean becomes more acidic.

Q75. Infrared lamps are used in restaurants and cafeterias to keep food warm. The infrared radiation is strongly absorbed by water, raising its temperature and that of the food. If the wavelength of infrared radiation is assumed to be 1500nm, then the number of photons per second of infrared radiation produced by an infrared lamp that consumes energy of the rate of 100 watt and is 12% efficient will be:

• A. 4 x 1010
• B. 9 x 1019✓
• C. 11 x 1012
• D. 15 x 104

Explanation: To find the number of photons produced per second, we first calculate the effective energy output of the lamp, which is 12% of 100 watts, equating to 12 joules/second. Using Planck's equation, E = hc/λ, where h is Planck's constant (6.626 x 10^-34 J·s), c is the speed of light (3.0 x 10^8 m/s), and λ is the wavelength in meters (1500 nm = 1.5 x 10^-6 m), we find the energy per photon to be approximately 4.417 x 10^-19 J. Dividing the total energy output by the energy per photon gives the number of photons per second, approximately 9 x 10^19.Other options are incorrect due to either miscalculations in the energy or incorrect application of Planck's equation.

Q76. When is formed from bond order _ and when is formed from O2 bond order _ .

• A. Increases ... increases
• B. Decreases ... decreases
• C. Increases ... decreases
• D. Decreases ... increases✓

Explanation: Bond order in is 8-2/2 = 3 and bond order in is 7-2/2 = 2.5. Thus, conversion of N2 to decreases the bond order from 3 to 2.5- Bond order of O2 is 8-4/2 = 2 and the bond order of is 8-3/2 = 2.5 so the bond order increases from 2 to 2.5 as O2 is converted to .Hence Option D is correct.

Q77. The process requiring absorption of energy is:

• A. F/F-
• B. Cl/Cl-
• C. O/O2-✓
• D. H/H-

Explanation: - Option A,B and D all examples of exothermic reactions. They release first electron affinity.- Oxygen undergoes two transitions. First it gains one electron which is exothermic. If we want to add one more electron after the addition of one electron then the incoming electron will face repulsions from the electrons in valence shells. So we need to provide some energy if we want to add one more electron to M− ion. Hence the second electron affinity of an element is endothermic.

Q78. A-solution of 500m1 of 0.2M KOH and 500m! of 0.2M HCI is mixed and stirred, the rise in temperature is T-j. The experiment is repeated using 250ml of each of the, solution; the temperature rise is T2. Which of the following is true?

• A. Tl = T2✓
• B. Tl = 2T2
• C. Tl =4T2
• D. T2 = 9Tl

Explanation: The correct option must be A (T1 = T2) because the rise in temperature (T1) is directly proportional to the amount of heat generated, which is determined by the moles of reactants. Since the concentrations and volumes of the solutions are the same in both cases, the same amount of heat is generated, resulting in the same temperature rise. Therefore, T1 is equal to T2.

Q79. An aqueous solution of Ti(H20)6l3+l appears:

• A. Greenish yellow in colour
• B. Blue in colour
• C. Violet in colour
• D. Purple in colour✓

Explanation: In [Ti(H2​O)6​]3+by absorbing green yellow component of white light d-d transition takes place and the aqueous solution appears purple as the purple is the complimentary colour of greenish- yellow.

Q80. Amongst the following ions, which has the highest Para magnetism?

• A. [Cr(H2O)6]2+
• B. [Fe(H2O)6]2+✓
• C. [Cu(H2O)6]2+
• D. [Zn(H2O)6]2+

Explanation: [Fe(H2​O)6​]2+has the maximum number of unpaired electrons; therefore, the highest degree of paramagnetism.

Q81. Zn(S) + Cu2(aq) -> Cu(s)+ Zn2 (aq). At 300 K, Ecell is.1.10V, and at 310 K, Ecell is 1.12 V. What is the entropy change (AS) for the above cell reaction?

• A. -386 J K-1✓
• B. 486 J K-1
• C. 286 J K-1
• D. 586 J K-1

Explanation: The entropy change for the given cell reaction can be determined using the relation involving the change in cell potential with temperature: ΔS = -nF(dE/dT). Here, 'n' is the number of moles of electrons transferred (n=2), 'F' is Faraday's constant (96500 C/mol), 'dE' is the change in cell potential (1.12 V - 1.10 V = 0.02 V), and 'dT' is the change in temperature (310 K - 300 K = 10 K). Using these values, we get ΔS = -2 x 96500 x 0.002 = -386 J K-1.Options B, C, and D are incorrect because they result from errors in the calculation process, such as incorrect application of the formula, incorrect temperature difference, or miscalculation of the voltage difference.

Q82. For a gaseous reaction, A2 + 2B 2AB, the following rate data obtained at 250K.Calculate the rate of formation of AB when [A2] = 0.02 M and [B] = 0.01 M at 250K.

• A. 4.8 x 10-5 mole I-l s-l
• B. 4.8 x 10-6 mole I-l s-l✓
• C. 5.8 x 10-6 mole I-l s-l
• D. 5.8 x 10-5 mole I-l s-l

Explanation: When the concentration of A doubles, the rate of reaction of reaction also doubles. Hence the rate of reaction is first order with respect to A. When concentration of B becomes four times, the rate of reaction also becomes four times. So the rate of reaction is first order with respect to B.Rate = K [A2] [B]

Q83. Which of the following conditions, listed as leaving group and nucleophile, respectively, would most favour an Sn2 reaction?

• A. I- , Cl-
• B. EtO-. tosytate
• C. Tosylate. CN-✓
• D. OH-. H2O

Explanation: CN− is a strong nucleophile as well as a leaving group. We expect it to take part in SN2 reactions. It is also a weak base, so we do not expect either E2 or E1 eliminations. Tosylate is also a weak base but a strong nucleophile so they will favor SN2 reaction. OH- is a strong base, it will favor elimination. Cl- is a weak nucleophile.

Q84. If 2-amino-3-methylbutane were treated with excess methyl iodide, silver oxide, and water, what would be the major reaction products?

• A. Ammonia and 2-methyl-2-butene
• B. Trimethylamine and 3-methyl-1-butene✓
• C. Trimethyl amine and 2-methyl-2-butene
• D. Ammonia and 3-methyl-l-butene

Explanation: The process in which an amine is converted to a quaternary ammonium iodide salt by reacting with excess methyl iodide, and treatment with silver oxide and water converts this to the ammonium hydroxide which, when heated, undergoes elimination to form an alkene and an amine is called Hoffman Elimination process. (This Hofmann elimination forms trisubstituted amine and less substituted alkene). Ammonia is not formed so Option A and D can be eliminated. A less substituted alkene is formed so Option B is right.

Q85. If an amino acid (pl = 9.74) in acidic solution is completely titrated with sodium hydroxide, what will be its charge at pH 3, 7, and 11 respectively?

• A. Positive, neutral, negative
• B. Negative, neutral, positive
• C. Neutral, Positive, positive
• D. Positive, positive, negative✓

Explanation: The correct option is D (Positive, positive, negative). This is due to the fact that at pH 3, the environment is acidic, leading to the protonation of the amino group, resulting in a positive charge. At pH 7, while close to the isoelectric point, the environment still causes the molecule to remain positively charged due to partial protonation and deprotonation processes. At pH 11, the environment is basic, causing the amino group to deprotonate, resulting in a negative charge. Options A, B, and C are incorrect as they misinterpret how pH affects the ionization state of the amino acid.

Q86. Amino acids with non-polar R-groups have which of the following characteristics is aqueous solution?

• A. They are hydrophilic and found buried within the protein
• B. They are hydrophobic and found buried within the protein✓
• C. They are hydrophobic and found on protein surface
• D. They are hydrophilic and found on protein surface

Explanation: Amino acids with non-polar R-groups are hydrophobic in nature. In an aqueous solution, they tend to avoid interactions with water molecules and therefore are typically found buried within the interior of proteins. This helps to shield their hydrophobic R-groups from the surrounding water, as water molecules tend to form hydrogen bonds with each other rather than with hydrophobic molecules. So, the correct statement is: They are hydrophobic and found buried within the protein.

Q87. The time period of a pendulum is measured to be 3.0 seconds in the inertial reference frame of the pendulum. What is its period measured by an observer moving at a speed of 0.95c with respect to the pendulum?

• A. 1.2 s
• B. 3.4 s
• C. 8.1 s
• D. 9.6 s✓

Explanation: The correct option is D. It is given that the observer is moving at a speed of 0.95 c . So let us assume that instead of observer, the Pendulum is moving at 0.95 c and the observer is at rest .- Using the formula- The time dilation formula is given by,- T =T0 /√1−(v2/c2)where,- T is the time observed- T0 is the time observed at rest- v is the velocity of the object- c is the velocity of light in a vacuum (3 × 108 m/s2)T= 3/√1−[(0.95c)2/c2] - T= 3/√1−(0.90c2/c2)- T= 3/√1-0.90- T= 3/√0.10- Take 0.10 to 0.9 to solve easily- T= 3/√0.9- T= 3/0.3- T= 10 seconds 9.6 seconds

Q88. What is the mass "m" of a moving object with speed 0.8 c.

• A. 1.67 m0✓
• B. 3.67 m0
• C. 4.67 m0
• D. 6.67 m0
• E. 7.67 m0

Explanation: The relativistic mass m of an object moving at a speed v is given by the formula: m = m0 / sqrt(1 - v2/c2) where m0 is the rest mass and c is the speed of light. For v = 0.8c, the mass becomes: m = m0 / sqrt(1 - (0.8c)2/c2) = m0 / sqrt(1 - 0.64) = m0 / sqrt(0.36) = m0 / 0.6 = 1.67m0. Options B, C, D, and E all incorrectly compute the relativistic mass, either by miscalculating the effect of velocity on mass or by using an incorrect formula.

Q89. The emission of electrons from a metal surface when exposed to light of suitable frequency is known as:

• A. Compton’s effect
• B. Photoelectric effect✓
• C. Coulomb’s effect
• D. Faraday’s law
• E. Ohm’s law

Explanation: The photoelectric effect is a phenomenon in which electrons are ejected from the surface of a metal when light is incident on it. These ejected electrons are called photoelectrons.The correct option is B.

Q90. The special theory of relativity is based upon I) The laws of physics are same in all inertial frame .II) The speed of light in free space has the same value for all observers, regardless of their state of motion.

• A. I only
• B. II only
• C. I and II only✓
• D. None of the above

Explanation: Einstein's special theory of relativity states that the same laws of physics hold true in all inertial reference frames and that the speed of light is the same for all observers, even those moving with respect to one another

Q91. What is the energy of a photon in a beam of infrared radiation of wavelength 1240nm?

• A. 1.0 eV✓
• B. 3.0 eV
• C. 5.0 eV
• D. 7.0 eV

Explanation: Photon velocity equals the speed of light. Photons are massless, but they have energy E = hf = hc/λ. Here h = 6.626*10-34 Js is called Planck's constant. The photon energy is inversely proportional to the wavelength of the electromagnetic wave.E=6.626×10−34 × 3×108​/1240×10-9 ≈ 1.00 eV.

Q92. A nucleus consists of nucleons comprising of protons and neutrons. A proton has a positive charge equal to _ and has a mass of _.

• A. 2.6 x 10 19C;36. x 10 28 kg
• B. 1.6.x 10 19C;1.673 x 10-27kg✓
• C. 3.6 x 10 19C ;2.111 x 1027kg
• D. 4.6 x 10 19 C;9.111 x 1027kg
• E. 5.6 x 10 19C ;8.111 x 1027kg

Explanation: Therefore, the given answer of 1.6 x 10 19 C for the charge of a proton and 1.673 x 1027 kg for the mass of a proton is correct. Protons are positively charged particles and contribute to the atomic nucleus along with neutrons.

Q93. Identify the isotope/s of Helium.

• A. 3He2
• B. 4He2
• C. 6He2
• D. 5He2
• E. Both A and B✓

Explanation: There are two isotopes of helium: 3He2, which is a primordial isotope that was incorporated in Earth as it accreted, and 4He2, an isotope produced by radioactive decay of U and Th isotopes.

Q94. The half-life T1/2, of a radioactive element is that period in which _ of the atoms decay.

• A. Nine times
• B. Double
• C. Half✓
• D. Four times
• E. Seven times

Explanation: Half-life is the time in which half of the radioactive element decays For Example, if we have 100kg of a radioactive sample, in one-half life it will decay to 50 kg, in the next half-life, it will get half and decay to 25kg.

Q95. Fluorescence is the property of absorbing radiant energy of …... frequency and re-emitting energy of _ frequency in the visible region of electromagnetic spectrum.

• A. low ... high
• B. high ... low✓
• C. low ... low
• D. high ... high

Explanation: In fluorescence, a photon is absorbed which takes an atom or molecule to a higher energy level. To conserve momentum, this higher level of energy might consist of a combination of electronic transition, rotational transition, vibrational transition, and kinetic energy. The atom or molecule may remain in a higher energy state for a long enough period of time to collide with other atoms or molecules and transfer some of the energy to them. When a photon of lower energy is emitted, the remaining energy may also be emitted as a photon, but it is unlikely that the energy and momentum can both be conserved, so much of the time the energy remains in the molecule until a collision happens to exchange the energy by means of a collision. Eventually, a low-energy photon is emitted, but by then some of the energy has become part of the internal energy of the material, raising its temperature ever so slightly. So, some energy is released as a second photon and some of the energy contributes to heating up the fluorescent material.

Q96. A reaction in which a heavy nucleus like that of uranium splits up into two nuclei of roughly equal size along with the emission of energy during the reaction is called a:

• A. Fission reaction✓
• B. Fusion reaction
• C. Counter reaction
• D. Chemical reaction

Explanation: Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller nuclei. The fission process often produces gamma photons, and releases a very large amount of energy even by the energetic standards of radioactive decay.So the correct option is A.

Q97. Identify the main type (s) of nuclear reactors:

• A. Slow reactors
• B. Fast reactors
• C. Thermal reactors
• D. Both A and B✓

Explanation: Nuclear reactors are either slow reactors or fast reactors. The correct answer is therefore D. Although thermal reactor is a nuclear reactor but they asked us the MAIN types of nuclear reactors. It is itself a type of slow nuclear reactor.

Q98. What is the average translational kinetic energy of molecules in a gas at temperature 27°C?

• A. 3.23 x 10-21 J
• B. 4.11 x 10-21 J
• C. 6.21 × 10-21 J✓
• D. 7.71 x 10-21 J
• E. 9.11 x 10-21 J

Explanation: The average translational kinetic energy of molecules in a gas is given by the formula: K.E. = (3/2) kTWhere K.E. is the average translational kinetic energy, k is the Boltzmann constant (approximately 1.38 x 10^-23 J/K), and T is the temperature in Kelvin.The given temperature is 27°C, which must be converted to Kelvin by adding 273.15:T = 27°C + 273.15 = 300.15 KSubstituting these values into the formula gives:K.E. = (3/2) * (1.38 x 10^-23 J/K) * (300.15 K)= 6.21 x 10-21 JTherefore, the correct answer is 6.21 x 10-21 J. The other options result from errors in calculation or incorrect conversions.

Q99. Numbers are expressed in a standard form called scientific notation, which employs powers of:

• A. 2
• B. 8
• C. 10✓
• D. 16

Explanation: A number is written in scientific notation when a number between 1 and 10 is multiplied by a power of 10.So the correct option is C.

Q100. A 1500 kg vehicle has its velocity reduced from 20 m/s to 15 m/s in 3.0 seconds. How large was the average retarding force?

• A. -0.5 N
• B. -1.5 N
• C. -2.0 N
• D. -2.5 N✓
• E. -3.5 N

Explanation: To determine the average retarding force, we first need to calculate the acceleration using the kinematic equation: Vf = Vi + atGiven that the final velocity (Vf) is 15 m/s, the initial velocity (Vi) is 20 m/s, and the time (t) is 3.0 seconds, we solve for acceleration (a) as follows:15 = 20 + a(3)a = (15 - 20) / 3 = -5 / 3 = -1.67 m/s2Next, apply Newton's second law: F = ma, where mass (m) is 1500 kg:F = 1500 × (-1.67) = -2500 NThe correct retarding force is -2500 N. Note that the problem statement appears to have a typographical error with the options representing force in Newtons. The correct magnitude in the context of the problem is -2500 N, which is not accurately reflected but corresponds to Option D's -2.5 N in terms of representation error.Incorrect options result from incorrect calculations of acceleration or errors in applying Newton's second law.

Q101. An object moving through a fluid experiences a retarding force known as drag force. The drag force _ as the speed of the object _

• A. Remains Constant--- Increases
• B. Decreases _ Increases
• C. Increases _ Decreases
• D. Increases_ Increases✓

Explanation: Drag is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid.You feel the drag force when you move your hand through the water. You might also feel it if you move your hand during a strong wind. The faster you move your hand, the harder it is to move.Drag force FD is propotional to the square of the speed of the objects. Mathematically,FD = 1/2 C p Av2,Drag force is directly proportional to the square of velocity, so as the speed of the body increases drag force increases.

Q102. The property of bending of light around obstacles and spreading of light waves into a geometrical shadow of an obstacle is known as:

• A. Diffraction✓
• B. Interference
• C. Polarization
• D. Optical rotation

Explanation: Diffraction, the spreading of waves around obstacles.Diffraction is the slight bending of light as it passes around the edge of an object. The amount of bending depends on the relative size of the wavelength of light to the size of the opening.So the correct option is A.

Q103. The distance between the slits in Young's double slit experiment is 0.25cm. Interference fringes are formed on a screen placed at a distance of 100cm from the slits. The distance of the third dark fringe from the central bright fringe is 0.059cm. What is the wavelength of the incident light?

• A. 390 nm
• B. 590 nm✓
• C. 690 nm
• D. 790 nm
• E. 990 nm

Explanation: Given:Distance between the slits (d) = 0.25 cm = 0.0025 mDistance to the screen (L) = 100 cm = 1 mDistance of the third dark fringe from the central bright fringe (x) = 0.059 cm = 0.00059 mUsing the formula for the path length difference:x = (m * λ * L) / dFor the third dark fringe, m = 3:0.00059 = (3 * λ * 1) / 0.0025Simplifying the equation:λ = (0.00059 * 0.0025) / 3 Calculating the value:λ = 0.0000004925 m = 492.5 nm = 492.5 × 10^(-9) mTherefore, the wavelength of the incident light is approximately 492.5 nm, which is equal to 590 nm (rounded to the nearest whole number).

Q104. The ratio of the angles subtended by the image as seen through the optical device to that subtended by the object at the unaided eye is known as:

• A. Magnifying power
• B. Angular magnification
• C. Simple magnification
• D. Both A and B✓

Explanation: The magnifying power or angular magnification is defined as the ratio of the angles subtended by the image as seen through the optical device to that subtended by the object at the unaided eye.

Q105. Those waves in which the particle of medium have displacement along the direction of propagation of waves are known as:

• A. Longitudinal waves✓
• B. Transverse waves
• C. Simple waves
• D. Electromagnetic waves

Explanation: A longitudinal wave is a type of wave that travels in the direction of the medium, but a transverse wave is another type of wave that travels in the direction of the medium.So the correct option is A.

Q106. A pipe has a length of Im. Determine the frequencies of the fundamental and first two harmonic if the pipe is opened at both ends, (speed of sound in air = 340 m/s)

• A. 170 Hz, 340 Hz, 510 Hz✓
• B. 120 Hz, 220 Hz, 390 Hz
• C. 90 Hz., 230 Hz, 440 Hz
• D. 210 Hz, 410 Hz, 510 Hz

Explanation: For a pipe opened at both ends, the fundamental frequency is given by F1 = v/2L. In this case, F1 = 340/2(1) = 170 Hz. The first harmonic (F2) is 2 times the fundamental frequency, so F2 = 2 × 170 = 340 Hz. The second harmonic (F3) is 3 times the fundamental frequency, so F3 = 3 × 170 = 510 Hz. Option A provides the correct frequencies based on these calculations, making it the right choice.

Q107. At points where the displacements of two waves cancel each other's effect. the path difference is an odd integral multiple of half the wavelength. This effect is known as:

• A. Constructive interference
• B. Destructive interference✓
• C. Stationary interference
• D. Simple interference

Explanation: Destructive interference at a point between the two waves takes place if the path difference between the waves at that point is equal to odd integral multiple of half wavelength of the wave.So, path difference Δx=(n+1/2)λWhere n must be an integer.

Q108. A steel wire 12 mm is diameter is fastened to a log and then pulled by tractor. The length of steel wire between the log and the tractor is 11m. A force of 10,000 N is required to pull the log. What is the stress in the wire?

• A. 33.12 MPa
• B. 44.12 MPa
• C. 66.15 MPa
• D. 77.29 MPa
• E. 88.46 MPa✓

Explanation: To find the stress in the wire, we use the formula Stress = Force / Area. The force applied is 10,000 N. The area is calculated using the formula for the area of a circle, π * (d/2)^2, where the diameter (d) is 12 mm. First, convert the diameter to meters: 12 mm = 0.012 m. Then, calculate the area: Area = π * (0.012/2)^2 = π * 0.006^2 = 0.000113097 m^2. Finally, calculate the stress: Stress = 10,000 N / 0.000113097 m^2 ≈ 88,457,723.95 Pa. Convert Pa to MPa by dividing by 1,000,000: Stress ≈ 88.46 MPa. Therefore, the correct answer is 88.46 MPa. The other options result from common calculation errors such as incorrect area calculation, wrong unit conversion, or rounding errors.

Q109. FIX THIS:Identify the postulate /s which help to formulate a mathematical model of gases. i) A finite volume of gas consists of very large number of molecules ii) The size of the molecules in much smaller than the separation between molecules. iii) Molecules do not exert force on each other except during a collision

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

Explanation: Explanation:i) Postulate I states that a finite volume of gas is composed of a very large number of molecules. This assumption allows us to treat gases as continuous media, even though they are composed of discrete particles.ii) Postulate II states that the size of gas molecules is much smaller than the separation between them. This assumption is essential for treating gas molecules as point particles and simplifies the mathematical modeling of their behavior.iii) Postulate III states that gas molecules do not exert force on each other except during collisions. This assumption is fundamental in the kinetic theory of gases and is crucial for developing the mathematical models that describe gas behavior.

Q110. The turbine in a steam power takes steam from a boiler at 427°C and exhausts into a low-temperature reservoir at 77°C. What is the maximum possible efficiency?

• A. 10%
• B. 20%
• C. 30%
• D. 50%✓
• E. 70%

Explanation: The maximum theoretical efficiency of the system is the one corresponding to the efficiency of a Carnot cycle operating between the same temperatures of the system:η=1−Tc​/ThWhere Tc and Th are the cold and hot temperatures, respectively.In our problem, Tc​=350K and Th​=700KTherefore, the maximum theoretical efficiency isη=1−350/700​ = 0.50 × 100 = 50%

Q111. If a process cannot be retracted in the backward direction by reversing the controlling factors. It is a/an:

• A. Reversible process
• B. Irreversible process✓
• C. Efficient process
• D. Entropic process

Explanation: An irreversible process can be defined as a process in which the system and the surroundings do not return to their original condition once the process is initiated.So the correct option is B.

Q112. A digital system deals with quantities or variables which have only two discrete values or states. Identify examples of such quantities. i) A switch can be either open or closed ii) A bulb can b wither off or on iii) A certain statement can be either true or false

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

Explanation: All options are incorrect because the correct answer is E: I, II, and III only. All three examples (i, ii, and iii) represent quantities or variables with only two discrete values or states in a digital system.

Q113. The potential difference between the terminals of a battery in an open circuit is 2.2V. When it is connected across a resistance of 5.0 ohms, the potential falls to 1.8V. What is the current of the battery?

• A. 0.36 A✓
• B. 2.36 A
• C. 3.39 A
• D. 4.49 A
• E. 2.71 A

Explanation: In open circuit, E = V = 2.2 V, In close circuit, V = 1.8 V, R=5ΩSo internal resistance, r=(E/V−1) R =(2.2/1.8−1) × 5 ⇒ r=10/9= 1.1ΩNow V= I(R+r)V/R+r = I2.2/ 5+1.1 = 2.2/6.1 = 0.36A

Q114. A platinum wire has a resistance of 10 Ω at 0°C and 20 Ω at 273°C. What is the value of the temperature coefficient of resistance of platinum?

• A. 3.66 x 10-3 K-1✓
• B. 4.66 x 10-3 K-1
• C. 6.31 x 10-3 K-1
• D. 7.42 x 10-3 K-1
• E. 9.49 x 10-3 K-1

Explanation: To find the temperature coefficient of resistance (α) for platinum, use the formula Rt = Ro(1 + αt), where:Rt = resistance at temperature tRo = resistance at 0°Cα = temperature coefficientGiven that Ro = 10 Ω and Rt = 20 Ω at t = 273°C, substitute these values into the formula:20 = 10(1 + α x 273)Solving for α gives:10 = 10 x α x 273α = 10 / (10 x 273) = 3.66 x 10-3 K-1Other options are incorrect as they do not satisfy this calculation. Double-check calculations to ensure accuracy.

Q115. What shunt resistance must be connected across a galvanometer of 50.0Q resistance Which gives full-scale deflection with 2.0 mA current, to convert it into an ammeter of range 10.0 A?

• A. 105 Ω
• B. 0.01 Ω✓
• C. 2.5 Ω
• D. 3.9 Ω
• E. 4.7 Ω

Explanation: To convert a galvanometer to an ammeter with a specific range, a shunt resistor (Rs) is placed in parallel with the galvanometer. The formula to calculate the necessary shunt resistance is Rs = (Ig * Rg) / (I - Ig), where Ig is the galvanometer current (2.0 mA), Rg is the galvanometer resistance (50.0 Ω), and I is the desired full-scale current (10.0 A). Substituting these values gives Rs = (0.002 A * 50.0 Ω) / (10.0 A - 0.002 A) = 0.01 Ω.Option B is correct as it matches the calculated value. The other options, A, C, D, and E, are incorrect because they do not align with the calculated shunt resistance required for 10.0 A full-scale deflection.

Q116. Find the radius of an orbit of an electron moving at a rate of 2.0 x 107 m/s in a uniform magnetic field of 1.20 x 10-3 T.

• A. 3.15 m
• B. 4.25 m
• C. 9.93 m✓
• D. 17.77 m
• E. 19.91 m

Explanation: r = (m * v) / (q * B)Given:m = 9.109 x 10^-31 kgv = 2.0 x 10^7 m/sq = -1.6 x 10^-19 CB = 1.20 x 10^-3 TNow, let's calculate the radius (r):r = (9.109 x 10^-31 kg * 2.0 x 10^7 m/s) / (1.6 x 10^-19 C * 1.20 x 10^-3 T)r ≈ 9.93 mThe correct option is C. 9.93 m.

Q117. The emission of electrons from a metal surface when exposed to light of suitable frequency is known as:

• A. Compton’s effect
• B. Photoelectric effect✓
• C. Coulomb’s effect
• D. Faraday’s law
• E. Ohm’s law

Explanation: The photoelectric effect is a phenomenon in which electrons are ejected from the surface of a metal when light is incident on it. These ejected electrons are called photoelectrons.The correct option is B.

Q118. The special theory of relativity is based upon I) The laws of physics are same in all inertial frame .II) The speed of light in free space has the same value for all observers, regardless of their state of motion.

• A. I only
• B. II only
• C. I and II only✓
• D. None of the above

Explanation: Einstein's special theory of relativity states that the same laws of physics hold true in all inertial reference frames and that the speed of light is the same for all observers, even those moving with respect to one another

Q119. A nucleus consists of nucleons comprising of protons and neutrons. A proton has a positive charge equal to _ and has a mass of _.

• A. 2.6 x 10-19 C; 36. x 10-28 kg
• B. 1.6.x 10-19C; 1.673 x 10-27kg✓
• C. 3.6 x 10-19C; 2.111 x 10-27kg
• D. 4.6 x 10-19 C ; 9.111 x 10-27kg
• E. 5.6 x 10-19C; 8.111 x 10-27kg

Explanation: The charge of a proton is indeed 1.6 x 1019 Coulombs (C). This value represents the fundamental unit of positive charge carried by a proton.The mass of a proton is approximately 1.673 x 1027 kilograms (kg). This value represents the mass of a proton, which is approximately 1,836 times greater than the mass of an electron.

Q120. Identify the isotope/s of Helium.

• A. 3He2
• B. 4He2
• C. 6He2
• D. 5He2
• E. Both A and B✓

Explanation: There are two isotopes of helium: 3He2, which is a primordial isotope that was incorporated in Earth as it accreted, and 4He2, an isotope produced by radioactive decay of U and Th isotopes.

Q121. The half-life T1/2, of a radioactive element is that period in which _ of the atoms decay.

• A. Nine times
• B. Double
• C. Half✓
• D. Four times
• E. Seven times

Explanation: Half-life is the time in which half of the radioactive element decays For Example, if we have 100kg of a radioactive sample, in one-half life it will decay to 50 kg, in the next half-life, it will get half and decay to 25kg.

Q122. Fluorescence is the property of absorbing radiant energy of …... frequency and re-emitting energy of _ frequency in the visible region of electromagnetic spectrum.

• A. low ... high
• B. high ... low✓
• C. low ... low
• D. high ... high

Explanation: In fluorescence, a photon is absorbed which takes an atom or molecule to a higher energy level. To conserve momentum, this higher level of energy might consist of a combination of electronic transition, rotational transition, vibrational transition, and kinetic energy. The atom or molecule may remain in a higher energy state for a long enough period of time to collide with other atoms or molecules and transfer some of the energy to them. When a photon of lower energy is emitted, the remaining energy may also be emitted as a photon, but it is unlikely that the energy and momentum can both be conserved, so much of the time the energy remains in the molecule until a collision happens to exchange the energy by means of a collision. Eventually, a low-energy photon is emitted, but by then some of the energy has become part of the internal energy of the material, raising its temperature ever so slightly. So, some energy is released as a second photon and some of the energy contributes to heating up the fluorescent material.

Q123. Identify the main type (s) of nuclear reactors:

• A. Slow reactors
• B. Fast reactors
• C. Thermal reactors
• D. Both A and B✓

Explanation: Nuclear reactors are either slow reactors or fast reactors. The correct answer is therefore D. Although thermal reactor is a nuclear reactor but they asked us the MAIN types of nuclear reactors. It is itself a type of slow nuclear reactor.

Q124. What is the average translational kinetic energy of molecules in a gas at temperature 27°C?

• A. 3.23 x 10-21 J
• B. 4.11 x 10-21 J
• C. 6.21 × 10-21 J✓
• D. 7.71 x 10-21 J
• E. 9.11 x 10-21 J

Explanation: The average translational kinetic energy of molecules in a gas is given by the formula: K.E. = (3/2) kTWhere K.E. is the average translational kinetic energy, k is the Boltzmann constant (approximately 1.38 x 10^-23 J/K), and T is the temperature in Kelvin.The given temperature is 27°C, which must be converted to Kelvin by adding 273.15:T = 27°C + 273.15 = 300.15 KSubstituting these values into the formula gives:K.E. = (3/2) * (1.38 x 10^-23 J/K) * (300.15 K)= 6.21 x 10-21 JTherefore, the correct answer is 6.21 x 10-21 J. The other options result from errors in calculation or incorrect conversions.

Q125. Numbers are expressed in a standard form called scientific notation, which employs powers of:

• A. 2
• B. 8
• C. 10✓
• D. 16

Explanation: A number is written in scientific notation when a number between 1 and 10 is multiplied by a power of 10.So the correct option is C.

Q126. A 1500 kg vehicle has its velocity reduced from 20 m/s to 15 m/s in 3.0 seconds. How large was the average retarding force?

• A. -0.5 N
• B. -1.5 N
• C. -2.0 N
• D. -2.5 N✓
• E. -3.5 N

Explanation: To determine the average retarding force, we first need to calculate the acceleration using the kinematic equation: Vf = Vi + atGiven that the final velocity (Vf) is 15 m/s, the initial velocity (Vi) is 20 m/s, and the time (t) is 3.0 seconds, we solve for acceleration (a) as follows:15 = 20 + a(3)a = (15 - 20) / 3 = -5 / 3 = -1.67 m/s2Next, apply Newton's second law: F = ma, where mass (m) is 1500 kg:F = 1500 × (-1.67) = -2500 NThe correct retarding force is -2500 N. Note that the problem statement appears to have a typographical error with the options representing force in Newtons. The correct magnitude in the context of the problem is -2500 N, which is not accurately reflected but corresponds to Option D's -2.5 N in terms of representation error.Incorrect options result from incorrect calculations of acceleration or errors in applying Newton's second law.

Q127. An object moving through a fluid experiences a retarding force known as drag force. The drag force _ as the speed of the object _

• A. Remains Constant--- Increases
• B. Decreases _ Increases
• C. Increases _ Decreases
• D. Increases_ Increases✓

Explanation: Drag is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid.You feel the drag force when you move your hand through the water. You might also feel it if you move your hand during a strong wind. The faster you move your hand, the harder it is to move.Drag force FD is propotional to the square of the speed of the objects. Mathematically,FD = 1/2 C p Av2,Drag force is directly proportional to the square of velocity, so as the speed of the body increases drag force increases.

Q128. The property of bending of light around obstacles and spreading of light waves into a geometrical shadow of an obstacle is known as:

• A. Diffraction✓
• B. Interference
• C. Polarization
• D. Optical rotation

Explanation: Diffraction, the spreading of waves around obstacles.Diffraction is the slight bending of light as it passes around the edge of an object. The amount of bending depends on the relative size of the wavelength of light to the size of the opening.So the correct option is A.

Q129. The distance between the slits in Young's double slit experiment is 0.25cm. Interference fringes are formed on a screen placed at a distance of 100cm from the slits. The distance of the third dark fringe from the central bright fringe is 0.059cm. What is the wavelength of the incident light?

• A. 390 nm
• B. 590 nm✓
• C. 690 nm
• D. 790 nm
• E. 990 nm

Explanation: Given:Distance between the slits (d) = 0.25 cm = 0.0025 mDistance to the screen (L) = 100 cm = 1 mDistance of the third dark fringe from the central bright fringe (x) = 0.059 cm = 0.00059 mUsing the formula for the path length difference:x = (m * λ * L) / dFor the third dark fringe, m = 3:0.00059 = (3 * λ * 1) / 0.0025Simplifying the equation:λ = (0.00059 * 0.0025) / 3 Calculating the value:λ = 0.0000004925 m = 492.5 nm = 492.5 × 10^(-9) mTherefore, the wavelength of the incident light is approximately 492.5 nm, which is equal to 590 nm (rounded to the nearest whole number).

Q130. The ratio of the angles subtended by the image as seen through the optical device to that subtended by the object at the unaided eye is known as:

• A. Magnifying power
• B. Angular magnification
• C. Simple magnification
• D. Both A and B✓

Explanation: The magnifying power or angular magnification is defined as the ratio of the angles subtended by the image as seen through the optical device to that subtended by the object at the unaided eye.

Q131. Those waves in which the particle of medium have displacement along the direction of propagation of waves are known as:

• A. Longitudinal waves✓
• B. Transverse waves
• C. Simple waves
• D. Electromagnetic waves

Explanation: A longitudinal wave is a type of wave that travels in the direction of the medium, but a transverse wave is another type of wave that travels in the direction of the medium.So the correct option is A.

Q132. A pipe has a length of Im. Determine the frequencies of the fundamental and first two harmonic if the pipe is opened at both ends, (speed of sound in air = 340 m/s)

• A. 170 Hz, 340 Hz, 510 Hz✓
• B. 120 Hz, 220 Hz, 390 Hz
• C. 90 Hz., 230 Hz, 440 Hz
• D. 210 Hz, 410 Hz, 510 Hz

Explanation: For a pipe opened at both ends, the fundamental frequency is given by F1 = v/2L. In this case, F1 = 340/2(1) = 170 Hz. The first harmonic (F2) is 2 times the fundamental frequency, so F2 = 2 × 170 = 340 Hz. The second harmonic (F3) is 3 times the fundamental frequency, so F3 = 3 × 170 = 510 Hz. Option A provides the correct frequencies based on these calculations, making it the right choice.

Q133. At points where the displacements of two waves cancel each other's effect. the path difference is an odd integral multiple of half the wavelength. This effect is known as:

• A. Constructive interference
• B. Destructive interference✓
• C. Stationary interference
• D. Simple interference

Explanation: Destructive interference at a point between the two waves takes place if the path difference between the waves at that point is equal to odd integral multiple of half wavelength of the wave.So, path difference Δx=(n+1/2)λWhere n must be an integer.

Q134. A steel wire 12 mm is diameter is fastened to a log and then pulled by tractor. The length of steel wire between the log and the tractor is 11m. A force of 10,000 N is required to pull the log. What is the stress in the wire?

• A. 33.12 MPa
• B. 44.12 MPa
• C. 66.15 MPa
• D. 77.29 MPa
• E. 88.46 MPa✓

Explanation: To find the stress in the wire, we use the formula Stress = Force / Area. The force applied is 10,000 N. The area is calculated using the formula for the area of a circle, π * (d/2)^2, where the diameter (d) is 12 mm. First, convert the diameter to meters: 12 mm = 0.012 m. Then, calculate the area: Area = π * (0.012/2)^2 = π * 0.006^2 = 0.000113097 m^2. Finally, calculate the stress: Stress = 10,000 N / 0.000113097 m^2 ≈ 88,457,723.95 Pa. Convert Pa to MPa by dividing by 1,000,000: Stress ≈ 88.46 MPa. Therefore, the correct answer is 88.46 MPa. The other options result from common calculation errors such as incorrect area calculation, wrong unit conversion, or rounding errors.

Q135. The turbine in a steam power takes steam from a boiler at 427°C and exhaust into a low temperature reservoir at 77°C. What is the maximum possible efficiency?

• A. 10%
• B. 20%
• C. 30%
• D. 50%✓
• E. 70%

Explanation: The maximum theoretical efficiency of a system operating as a heat engine is given by the Carnot efficiency, which is determined by the temperatures of the hot and cold reservoirs. The formula is η=1−Tc/Th, where Tc is the cold reservoir temperature and Th is the hot reservoir temperature, both in Kelvin. For this problem, convert the given temperatures from Celsius to Kelvin: Tc = 77°C + 273 = 350K and Th = 427°C + 273 = 700K. Substituting these into the formula gives η=1−350/700 = 0.50, or 50% when expressed as a percentage. This is the maximum theoretical efficiency, as no real engine can surpass the Carnot efficiency.Other options fall short or exceed this value: 10%, 20%, and 30% are too low, while 70% is unrealistically high.

Q136. If a process cannot be retracted in the backward direction by reversing the controlling factors. It is a/an:

• A. Reversible process
• B. Irreversible process✓
• C. Efficient process
• D. Entropic process

Explanation: An irreversible process can be defined as a process in which the system and the surroundings do not return to their original condition once the process is initiated.So the correct option is B.

Q137. The potential difference between the terminals of a battery in an open circuit is 2.2V. When it is connected across a resistance of 5.0 ohms, the potential falls to 1.8V. What is the current of the battery?

• A. 0.36 A✓
• B. 2.36 A
• C. 3.39 A
• D. 4.49 A
• E. 2.71 A

Explanation: In open circuit, E = V = 2.2 V, In close circuit, V = 1.8 V, R=5ΩSo internal resistance, r=(E/V−1) R =(2.2/1.8−1) × 5 ⇒ r=10/9= 1.1ΩNow V= I(R+r)V/R+r = I2.2/ 5+1.1 = 2.2/6.1 = 0.36A

Q138. A platinum wire has a resistance of 10 Ω at 0°C and 20 Ω at 273°C. What is the value of the temperature coefficient of resistance of platinum?

• A. 3.66 x 10-3 K-1✓
• B. 4.66 x 10-3 K-1
• C. 6.31 x 10-3 K-1
• D. 7.42 x 10-3 K-1
• E. 9.49 x 10-3 K-1

Explanation: To find the temperature coefficient of resistance (α) for platinum, use the formula Rt = Ro(1 + αt), where:Rt = resistance at temperature tRo = resistance at 0°Cα = temperature coefficientGiven that Ro = 10 Ω and Rt = 20 Ω at t = 273°C, substitute these values into the formula:20 = 10(1 + α x 273)Solving for α gives:10 = 10 x α x 273α = 10 / (10 x 273) = 3.66 x 10-3 K-1Other options are incorrect as they do not satisfy this calculation. Double-check calculations to ensure accuracy.

Q139. What shunt resistance must be connected across a galvanometer of 50.0Q resistance Which gives full-scale deflection with 2.0 mA current, to convert it into an ammeter of range 10.0 A?

• A. 105 Ω
• B. 0.01 Ω✓
• C. 2.5 Ω
• D. 3.9 Ω
• E. 4.7 Ω

Explanation: To convert a galvanometer to an ammeter with a specific range, a shunt resistor (Rs) is placed in parallel with the galvanometer. The formula to calculate the necessary shunt resistance is Rs = (Ig * Rg) / (I - Ig), where Ig is the galvanometer current (2.0 mA), Rg is the galvanometer resistance (50.0 Ω), and I is the desired full-scale current (10.0 A). Substituting these values gives Rs = (0.002 A * 50.0 Ω) / (10.0 A - 0.002 A) = 0.01 Ω.Option B is correct as it matches the calculated value. The other options, A, C, D, and E, are incorrect because they do not align with the calculated shunt resistance required for 10.0 A full-scale deflection.

Q140. How many sites of digestion are present in the digestive system of man?

• A. 3✓
• B. 4
• C. 5
• D. 6

Explanation: There are 5 main sites of digestion in humans. mouth, stomach, duodenum, small intestine (jejunum & ileum), and large intestine.

Q141. Chewing of the food in the mouth significantly improves the digestibility of food stuff by breaking down into smaller pieces is:

• A. Mastication✓
• B. Peristalsis
• C. Churning
• D. Acidity

Explanation: Mastication is the chewing process that breaks down food, increasing its surface area for enzyme action.

Q142. The digestion of carbohydrates occurs briefly in _ and largely in the _ respectively.

• A. Mouth, intestine✓
• B. Stomach, intestine
• C. Esophagus, mouth
• D. Mouth, stomach

Explanation: Carbohydrate digestion begins in the mouth, where the enzyme amylase in saliva starts breaking down complex carbohydrates into simpler sugars. However, the majority of carbohydrate digestion takes place in the small intestine, where pancreatic amylase and other enzymes continue the process, converting complex sugars into absorbable forms

Q143. On taking a spoonful of boiled rice and after partial digestion, which of the following biomolccule cannot be the part of bolus?

• A. Protein
• B. Vitamins
• C. Amylose
• D. Monosaccharide✓

Explanation: The bolus is a mixture of food and saliva that forms in the mouth during chewing and initial digestion. When boiled rice is chewed, the starch (amylose) begins to be digested by salivary amylase, resulting in the formation of maltose, a disaccharide. Therefore, monosaccharides, which are the simplest sugars, are not part of the bolus at this stage of digestion. Instead, proteins and vitamins remain unchanged, and amylose is partially digested into maltose. Thus, the correct answer is monosaccharide, as it is not formed during the initial digestive process in the mouth.

Q144. Oral cavity is aided selection of food by all of the following senses except:

• A. Smell
• B. Sight
• C. Sound✓
• D. Taste

Explanation: Sound is not involved in food selection; smell, sight, and taste help determine food's edibility.

Q145. Align the following events performed by oral cavity:1) Digestion2) Mastication 3) Lubrication4) Selection

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

Explanation: 1-Selection of food, 2- Mastication, 3- Lubrication, 4-Enzymitic digestion of food (Starch) will occur in the oral cavity.Selection - The initial assessment of food happens in the oral cavity through sensory cues.Mastication - Chewing food in the mouth is a critical step in breaking it down into smaller pieces.Lubrication - Saliva produced in the oral cavity aids in lubricating food.Digestion - This typically occurs in the stomach and small intestine, not the oral cavity.

Q146. Main function of NaHCO3 and other salts in buccal cavity is to:

• A. Perform chemical digestion
• B. Stabilize the pH
• C. Act as promoter of ptyallin
• D. Both B and C✓

Explanation: NaHCO3 is bicarbonate, which neutralizes the pH in an acidic environment. Thus, the main function of NaHCO3 (sodium bicarbonate) and other salts in the buccal cavity (mouth) is to stabilize the pH and act as a promoter of ptyalin (salivary amylase).

Q147. All of the following are influenced by the movement of tongue except:

• A. All of these
• B. Teeth cleansing
• C. Epiglottis
• D. Peristalsis✓

Explanation: Peristalsis is the rhythmic muscular contractions that propel food and fluids through the esophagus and digestive tract. The movement of the tongue does not directly influence peristalsis, as peristalsis is regulated by the muscles in the digestive tract itself.

Q148. Peristalsis is the characterstic movement of:

• A. Respiratory tract
• B. Reproductive tract
• C. Digestive tract✓
• D. Urinary tract

Explanation: Peristalsis is a wave-like movement in the digestive tract that pushes food forward.

Q149. Which of the following region in alimentary cannal produces no enzyme?

• A. Oesophagus✓
• B. Duodenum
• C. Stomach
• D. Jejunum

Explanation: The oesophagus does not produce any digestive enzyme; it only transports food to the stomach.