Etea Mdcat 2016 — Solved Past Paper with Answers

Q1. Choose the correct sentence.

• A. Does your tram leaw before eight o'clock?
• B. Does your train leave before eight clock?
• C. Does your train leave before eight o'clock?✓
• D. Do your train leave before eight o'clock?

Explanation: The correct sentence is Option C: "Does your train leave before eight o'clock?" This sentence correctly uses "Does" as the auxiliary verb with the singular subject "your train" to form the present tense question. It also includes the correct spelling of "leave" and "o'clock."Option A is incorrect due to the misspelling of "leaw," which should be "leave." Option B omits "o'clock," making it incomplete in expressing time. Option D uses "Do" incorrectly with the singular subject "train," which requires "Does."

Q2. _ my mind, what we need in this company is a better marketing plan

• A. For
• B. In✓
• C. To
• D. At

Explanation: In: This is the correct choice. The phrase "In my mind" means in my opinion or according to my thoughts.

Q3. Your friend proved more sympathetic than I expected he _ do.

• A. Will
• B. Shall
• C. Would✓
• D. Should

Explanation: “Would” highlights a sense of expectation for the future or from the perspective of an expectation set in the past for some time yet to elapse.Would is an auxiliary verb - a modal auxiliary verb. We use would mainly to:talk about the pasttalk about the future in the pastexpress the conditional moodWe also use would for other functions, such as:expressing desire, polite requests and questions, opinion or hope, wish and regret.

Q4. Select the correct indirect speech:"I am disappointed that you feel you have to lie to me, Jason," said his father.

• A. His father said to Jason that he was disappointed to know that he had to lie to him.
• B. Jason's father told him that he was disappointed that he felt he had to lie to him.
• C. Jason's father said that he was disappointed to know that he felt he had to lie to him.✓
• D. Jason's father expressed disappointment and mentioned he was sorry that Jason had to lie.

Explanation: The correct indirect speech is: Jason's father said that he was disappointed to know that he felt he had to lie to him.The original direct speech is: "I am disappointed that you feel you have to lie to me, Jason," said his father. The conversion involves changing 'am' to 'was' and 'feel' to 'felt' to match the past tense of the reporting verb 'said.'Option A incorrectly alters the sentence structure and meaning. Option B changes the reporting verb from 'said' to 'told,' altering the original context. Option D introduces 'sorry,' which is not present in the original sentence.

Q5. Choose the word most similar in meaning to the capitalized word "OBLITERATE":

• A. Offend
• B. Haul
• C. Rent
• D. Destroy✓

Explanation: The word 'obliterate' means to destroy completely or wipe out. Option D, 'Destroy', is the correct answer as it directly aligns with this definition. 'Offend', 'haul', and 'rent' do not convey the idea of destruction or elimination, making them incorrect choices.

Q6. The revolution in art has not lost its steam; it _ on as fiercely as ever.

• A. Trudges
• B. Meanders
• C. Ambles
• D. Rages✓

Explanation: The correct answer is Rages because it conveys the idea of something continuing with intensity and force, which matches the depiction of the art revolution in the sentence. The other options—Trudges, Meanders, and Ambles—do not capture the intensity or the fierce, ongoing nature of the revolution in art. These words imply slowness or a lack of direction, which is contrary to the sentence's emphasis on intensity and persistence.

Q7. Select the correct passive voice:The principal has forbidden smoking on the campus.

• A. Smoking has been forbidden on the campus by the principal.✓
• B. Smoking had been forbidden on the campus by the principal.
• C. Smoking was being forbidden on the campus by the principal.
• D. It is forbidden by the principal to smoke on campus.

Explanation: The correct passive voice conversion of 'The principal has forbidden smoking on the campus.' is 'Smoking has been forbidden on the campus by the principal.' In passive voice transformation, the object of the active sentence ('smoking') becomes the subject in the passive sentence, while the subject ('the principal') is turned into the agent. The tense remains the same: present perfect. Option B changes the tense to past perfect, Option C uses past continuous, and Option D transforms the sentence into a different structure, none of which correctly reflects the original sentence's intent.

Q8. Choose the word opposite in meaning to the capitalized word "TANGIBLE":

• A. Embodied
• B. Conceptual✓
• C. Phenomenal
• D. Verifiable

Explanation: The correct answer is Option B: 'Conceptual'. The word 'tangible' refers to something that can be touched or physically felt. In contrast, 'conceptual' refers to an idea or concept that exists in the mind and cannot be physically touched. The other options do not provide a true opposite meaning:Embodied: Suggests giving a tangible form to an idea, not the opposite of tangible.Phenomenal: While it can mean extraordinary, it can also refer to observable phenomena, not the opposite of tangible.Verifiable: Implies something can be confirmed or proven, often with tangible evidence, not the opposite of tangible.

Q9. Together the old man and the young boy washed the dishes.Select the correct passive voice:

• A. The old man and the young boy were washing the dishes together.
• B. The old man and the young boy together washed the dishes.
• C. The dishes were washed by the old man and the young boy together.✓
• D. Together, the old man and the young boy wash the dishes.

Explanation: In the original active voice sentence, 'Together the old man and the young boy washed the dishes,' the subjects (the old man and the young boy) perform the action. In converting to passive voice, the object of the active sentence ('the dishes') becomes the subject, and the verb 'wash' is changed to its past participle form 'were washed,' with the original subjects ('the old man and the young boy') becoming the agents introduced by 'by.'The passive voice sentence 'The dishes were washed by the old man and the young boy together' emphasizes the action on the dishes rather than who performed it.Option A and B remain in active voice, and Option D changes the tense to present and remains active. Only Option C accurately reflects the passive form with correct emphasis.

Q10. Communication technology has brought a tremendous revolution in modern societies. Select the correct passive voice:

• A. A tremendous revolution has been brought by communication technology in modern societies.✓
• B. In modern societies, a tremendous revolution has been brought in communication technology.
• C. A tremendous revolution has brought in communication technology in modern societies.
• D. Communication technology has tremendous revolution brought in modern societies.

Explanation: The original sentence "Communication technology has brought a tremendous revolution in modern societies" is in the active voice, with 'communication technology' as the subject performing the action of 'bringing.' In passive voice, we change the structure so that 'a tremendous revolution' becomes the subject, thus focusing on the action's receiver. Therefore, the correct sentence is 'A tremendous revolution has been brought by communication technology in modern societies.' Here, 'has been brought' is the passive verb form, and 'by communication technology' indicates the agent. Other options incorrectly structure the passive sentence or suggest incorrect relationships between the subject and action.

Q11. I insist _ the withdrawal of your statement.

• A. For
• B. On✓
• C. At
• D. In

Explanation: The phrase 'insist on' is a standard idiomatic expression in English, indicating that someone is demanding or considering something essential. Thus, 'on' is the correct preposition to follow 'insist' in this context. The other options, 'for', 'at', and 'in', do not fit the idiom and would not make sense in this sentence structure.

Q12. As you have not prepared your work, ……

• A. Your likelihood of success is significantly reduced✓
• B. You could still perform exceptionally well
• C. You should plan to prepare thoroughly next time
• D. You will inevitably fail

Explanation: The correct answer is 'Your likelihood of success is significantly reduced.' This response acknowledges the typical outcome of not preparing, which is a decreased chance of success. While unexpected positive outcomes can occur, they are not the norm. The other options either dismiss the importance of preparation, provide advice for future scenarios instead of addressing the current one, or assume an outcome without room for variability.

Q13. Choose the word opposite in meaning to the capitalized word "ANARCHIC":

• A. Riotous
• B. Turbulent
• C. Disordered
• D. Organized✓

Explanation: The word 'anarchic' implies a lack of order or control, akin to chaos. Hence, its opposite would be 'organized,' which indicates a state of order and structure. The other options, 'riotous,' 'turbulent,' and 'disordered,' all suggest a lack of order or stability, similar to 'anarchic,' rather than opposing it.

Q14. "Frown on somebody" means to:

• A. Fall flat upon a stranger
• B. Stay alive working hard
• C. Unable to be successful
• D. Disapprove of somebody✓

Explanation: The phrase 'frown on somebody' is a phrasal verb that means to disapprove of someone or something. It is often used to express judgment or disapproval of actions or behaviors that are considered undesirable. Option A (Fall flat upon a stranger) and Option B (Stay alive working hard) are unrelated to the concept of disapproval. Option C (Unable to be successful) indicates a lack of achievement but not disapproval from others. Therefore, the correct answer is Option D, which accurately reflects the meaning of the phrasal verb.

Q15. Choose the word most similar in meaning to the capitalized word "PRODIGIOUS".

• A. Enormous✓
• B. Sacred
• C. Seismic
• D. Tiny

Explanation: The word 'prodigious' is used to describe something that is extraordinarily large, impressive, or extensive. Therefore, 'Enormous' is the correct choice as it shares this characteristic of great size or degree. 'Sacred' is associated with holiness and divinity, 'Seismic' pertains to earthquakes, and 'Tiny' is the opposite of 'prodigious', as it means very small.

Q16. If you like sport, this is a great place. There‘s a lot to choose _.

• A. Among
• B. From✓
• C. At
• D. For

Explanation: The correct preposition to use in this context is 'from,' as it indicates that there is a range of options available and allows for the selection of one or more items. 'Among' could work if emphasizing a choice within a group, but it typically implies a singular choice. 'At' and 'for' do not fit the context of choosing options and are incorrect prepositions to use in this sentence structure.

Q17. The candidate _ when asked why he had left his last job; he did not want to admit that he had been dismissed.

• A. Demurred
• B. Confided
• C. Dissembled✓
• D. Rejoiced

Explanation: The correct answer is 'dissembled' because it means to conceal or disguise one's true feelings or intentions. In the context of the question, the candidate is trying to avoid admitting the truth about being dismissed. The other options are incorrect: 'demurred' suggests objection or hesitation, which doesn't align with the idea of concealing information; 'confided' implies sharing a secret, which is the opposite of concealing it; and 'rejoiced' implies a positive emotional response, which does not fit the situation described.

Q18. Choose the sentence with correct punctuation:

• A. However, it didn't take long for others to jump on board.✓
• B. However it didn't take long for others to jump on board.
• C. However, it didn't take long for others to jump on board?
• D. However. It didn't take long for others to jump on board.

Explanation: The correct option is: "However, it didn't take long for others to jump on board." A comma is necessary after the introductory word "However" to create a pause and connect it properly to the main clause.

Q19. Choose the correct narration:Anwar said, "Naveed must go tomorrow".

• A. Anwar declared that Naveed must go the following day
• B. Anwar exclaimed that Naveed would have to go the following day
• C. Anwar said that Naveed would have to go the following day✓
• D. Anwar said that Naveed shall go the following day

Explanation: Option (c), "Anwar said that Naveed would have to go the following day," is the correct choice. It appropriately changes "must" to "would have to," reflecting the necessity expressed by Anwar while also shifting "tomorrow" to "the following day" to match the indirect speech format. This maintains the meaning of the original statement

Q20. The tissues present in anglosperms but absent in gymnosperms are:

• A. Vessels
• B. Companion cells
• C. Sieve tubes
• D. Both (a) and (b)✓

Explanation: The correct answer is both (a) and (b). Angiosperms have unique vascular tissues, such as vessels and companion cells, which are not found in gymnosperms. Vessels are crucial for efficient water transport, while companion cells support sieve elements in carbohydrate transport. The lack of these specialized cells in gymnosperms affects their transport efficiency and growth habits. Sieve tubes, while part of the phloem in angiosperms, depend on companion cells, which are absent in gymnosperms, making option (c) incorrect.

Q21. Individuality of every persons is maintained by nucleotide genome sequence difference of:

• A. 0.1%✓
• B. 2%
• C. 3%
• D. 5%

Explanation: Human beings share 99.9% of their genome sequence, making 0.1% the portion that accounts for individual genetic differences. This small percentage is responsible for the vast diversity observed among individuals. The larger percentages, such as 2%, 3%, or 5%, do not accurately reflect the minor genetic variations that exist among humans and would imply a far greater level of genetic diversity than actually exists.

Q22. Mature cells of cartilage are:

• A. Chondrocytes✓
• B. Osteocytes
• C. Osteoblasts
• D. Osteoclasts

Explanation: Cartilage, a type of connective tissue, contains specialized cells known as chondrocytes. These cells are embedded in small spaces within the cartilage matrix called lacunae. Chondrocytes play a crucial role in both the production and maintenance of the cartilage matrix, as well as in the repair of damaged cartilage. In contrast, osteocytes, osteoblasts, and osteoclasts are all associated with bone tissue. Osteocytes are mature bone cells, osteoblasts are involved in bone formation, and osteoclasts are responsible for bone resorption.

Q23. Of the following the dioecous plant be:

• A. Sunflower
• B. Wheat
• C. Mulberry✓
• D. Maize

Explanation: Dioecious plants, such as Mulberry, have separate male and female individuals, meaning individual plants are either male or female, not both. This requires both male and female plants for reproduction. In contrast, Sunflower, Wheat, and Maize are monoecious, where each plant carries both male and female flowers, facilitating self-pollination or close proximity pollination without the need for separate male and female plants.

Q24. Each kidney of human being is weighing about:

• A. 140 grams
• B. 160 grams✓
• C. 130 grams
• D. 150 grams

Explanation: The average weight of each human kidney is about 160 grams. This value can vary slightly based on factors such as age, gender, and overall health, but 160 grams is a widely accepted average. The other options, although close, do not accurately reflect this average weight. The options of 140 grams and 150 grams are slightly below the average, while 130 grams is significantly lower and unlikely.

Q25. Which one of the following discovered the vaccine for first time against the small pox in 1796.

• A. Edward Jenner✓
• B. Louis Pasteur
• C. F. H. Herbor
• D. James Phipps

Explanation: Edward Jenner is credited with developing the first successful smallpox vaccine in 1796. He used material from cowpox lesions to inoculate an 8-year-old boy named James Phipps. Jenner's work laid the groundwork for the field of immunology. Louis Pasteur, while a significant figure in the development of vaccines, was associated with different vaccines. The name F. H. Herbor does not relate to any known vaccine development, and James Phipps was the recipient, not the creator, of the vaccine.

Q26. The main axis culminates in a flower and produces three or more daughter axis each of which continues the branching in similar manner is know as:

• A. Uniparous cyme
• B. Biparous cyme
• C. Multiparous cyme✓
• D. Cymose capitulum

Explanation: The correct answer is multiparous cyme. In this type, the main axis culminates in a flower and branches into three or more daughter axes, each of which can further branch in a similar manner. This is distinct from the uniparous cyme, which branches with only one daughter axis, and the biparous cyme, which branches with two. The cymose capitulum, on the other hand, is a different inflorescence type where the main axis is short and ends in a cluster of flowers, not characterized by branching.

Q27. The ripened & fertilized ovule is called:

• A. Fruit
• B. Seed✓
• C. Endosperm
• D. Perisperm

Explanation: The ripened and fertilized ovule is called a seed. Seeds are crucial for plant reproduction and consist of three main components: the embryo (future plant), the endosperm (nutrient provider), and the seed coat (protection). While a fruit is a mature ovary that houses seeds, it is not the seed itself. The endosperm is a part of the seed that nourishes the embryo, and perisperm, found in some seeds, is a residual nutritive tissue. These components play distinct roles within the seed structure but do not define the seed itself.

Q28. Which one of the following comes into existence when bacterial plasmid naturally modified to produce it?

• A. pBR 322✓
• B. Npq 303
• C. oSR 210
• D. kMG 319

Explanation: The correct answer is pBR 322. Plasmids like pBR 322 are naturally occurring extrachromosomal DNA molecules in bacteria that have been modified to serve as vectors in genetic engineering. These plasmids can carry genes for antibiotic resistance, making them useful in gene cloning and other molecular biology applications. The other options, Npq 303, oSR 210, and kMG 319, do not correspond to known plasmids and are not used in this context.

Q29. Exophthalmia is a classic symptom of:

• A. Hyperthyroidism✓
• B. Hypocalcemia
• C. Hypochondria
• D. Hypercalcemia

Explanation: Exophthalmia, the abnormal protrusion of the eyes, is typically associated with Graves' disease, a form of hyperthyroidism. This condition arises when the thyroid gland produces excessive thyroxine, leading to metabolic imbalances and symptoms such as increased heart rate and weight loss. Exophthalmia occurs due to the buildup of tissue behind the eyes, a common feature in Graves' disease.In contrast, hypocalcemia and hypercalcemia are conditions related to abnormal calcium levels in the blood, with distinct symptoms unrelated to eye protrusion. Hypochondria is a psychological condition involving health anxiety, not a physical symptom like exophthalmia.

Q30. Percentage of CO2 carried by plasma proteins is:

• A. 5%
• B. 6%
• C. 7%✓
• D. 8%

Explanation: Carbon dioxide (CO2) is transported in the blood in three main forms. Approximately 7% of CO2 is transported bound to plasma proteins, which is a minor but significant component of CO2 transport. The majority of CO2 (about 70%) is converted to bicarbonate ions in the plasma, while around 20% is carried by hemoglobin as carbaminohemoglobin. Therefore, option C is correct. Options A, B, and D are incorrect because they either underestimate or overestimate the percentage of CO2 carried by plasma proteins.

Q31. CSF Is found in between:

• A. Pia mater and dura mater
• B. Pia mater and arachnoid mater✓
• C. Grey matter and pia mater
• D. Dura mater and grey mater

Explanation: Cerebrospinal fluid (CSF) is a clear, colorless liquid that fills and surrounds the brain and the spinal cord and provides a mechanical barrier against shock. It occupies the subarachnoid space (between the arachnoid mater and the pia mater) and the ventricular system around and inside the brain and spinal cord. Formed primarily in the ventricles of the brain, the cerebrospinal fluid supports the brain and provides lubrication between surrounding bones and the brain and spinal cord. When an individual suffers a head injury, the fluid acts as a cushion, dulling the force by distributing its impact.

Q32. Kelps are:

• A. Diatoms
• B. Red-algae
• C. Green-algae
• D. Brown-algae✓

Explanation: Kelps are brown algae, known for their large size and complex structure, often forming dense underwater forests in cold oceanic regions. These forests provide critical habitat and resources for marine organisms. In contrast, diatoms are small, silica-walled algae, red algae are smaller and have a distinct red pigment, and green algae do not reach the size or complexity of kelps.

Q33. Independent gametophyte and sporophyte are found in:

• A. Selaginella
• B. Polytrichum
• C. Ectocarpus✓
• D. Liverworts

Explanation: The correct answer is Ectocarpus. In Ectocarpus, both the gametophyte and sporophyte stages are independent of each other, which is characteristic of its alternation of generations. This is unlike most non-vascular plants like Polytrichum (mosses) and Liverworts, where the sporophyte is dependent on the gametophyte. Selaginella, although having a complex life cycle with heterospory, does not have fully independent gametophytes.

Q34. The guard cell of the stomata in Monocot is:

• A. Kidney shape
• B. Oval
• C. Rounded
• D. Dumbbell shaped✓

Explanation: The correct answer is dumbbell-shaped. Monocots have stomatal guard cells that are dumbbell-shaped, allowing for better regulation of gas exchange. This shape is better suited for monocots, which often grow in environments where water conservation is critical. In contrast, dicots usually have kidney-shaped guard cells, which are adapted to their specific environmental conditions. The other options, such as kidney, oval, and rounded shapes, do not accurately represent the typical guard cell shape found in monocots.

Q35. Photorespiration involved the following reaction which occurs in the sequence of:

• A. Glycolate --> Glycine, Glycine --> Serine + CO2, RuBP + O2 --> Glycolate
• B. RuBP + O2 --> Glycolate, Glycine --> Serine + CO2, Glycolate --> Glycine
• C. RuBP + O2 --> Glycolate, Glycolate --> Glycine, Glycine --> Serine + CO2✓
• D. Glycine --> Serine + CO2, RuBP + O2 --> Glycolate, Glycolate --> Glycine

Explanation: Photorespiration is a process in plants where RuBP (Ribulose Bisphosphate) reacts with oxygen, rather than carbon dioxide, leading to a series of reactions:1. RuBP + O2 --> Glycolate: RuBP oxygenation is the first step, producing glycolate.2. Glycolate --> Glycine: Glycolate is then converted to glycine.3. Glycine --> Serine + CO2: Finally, glycine is converted to serine with the release of CO2.Option C correctly follows this sequence. Options A, B, and D misrepresent the order of these reactions, either starting with or incorrectly placing the reactions, which makes them incorrect.

Q36. Which of the following statement is correct?

• A. Inspiration is an active process✓
• B. Expiration is a passive process
• C. Inspiration is a passive process
• D. Both expiration and inspiration are passive processes

Explanation: Inspiration is an active process because it involves the contraction of the diaphragm and intercostal muscles, which results in the expansion of the thoracic cavity and reduces pressure inside the lungs, allowing air to flow in. On the other hand, expiration is typically a passive process because it relies on the relaxation of these muscles and the natural elastic recoil of the lungs and chest wall to expel air. In certain conditions, such as forced breathing, expiration can become active, but under normal resting conditions, it remains passive.

Q37. Porifera is related to the sub Kingdom of:

• A. Protozoa
• B. Parazoa✓
• C. Metazoa
• D. Aves

Explanation: Porifera, commonly known as sponges, belong to the subkingdom Parazoa within the kingdom Animalia. Parazoa is characterized by simple multicellular organisms that lack true tissues. This distinguishes them from the more complex tissue organization found in the subkingdom Metazoa, which includes most other animals. Protozoa are not part of the animal kingdom and are instead considered protists. Aves, being a class within the subphylum Vertebrata, are not related to the simple structure of Porifera.

Q38. The females of one of the following classes possess a single overy, that is:

• A. Pisces
• B. Amphibia
• C. Reptilia
• D. Aves✓

Explanation: The correct answer is Aves. Female birds generally possess a single ovary on the left side of their body, an adaptation believed to support flight by minimizing body weight. In contrast, the other vertebrate classes listed—Pisces, Amphibia, and Reptilia—usually have two ovaries. This bilateral ovary arrangement is suited to their respective environments and does not have the weight constraints associated with flight.

Q39. The florescent pigments in the eyes of fruit fly is an example of:

• A. Overdominance✓
• B. Complete dominance
• C. Incomplete dominance
• D. Co-dominance

Explanation: The correct answer is Overdominance. In the case of fluorescent pigments in the eyes of fruit flies, heterozygotes may exhibit a more pronounced or advantageous trait compared to either homozygote, a characteristic of overdominance. This can result in benefits such as enhanced visibility or increased attractiveness, potentially improving fitness.Complete dominance is incorrect because it involves one allele completely masking the other, which does not apply here. Incomplete dominance is also incorrect as it results in an intermediate phenotype, not observed in this context. Finally, Co-dominance is not applicable because it involves simultaneous full expression of both alleles rather than a unique, advantageous heterozygous trait.

Q40. The roots given out from rhizome of fern are called:

• A. Pneumatophore
• B. Phizophores
• C. Rhizoids
• D. Adventitious roots✓

Explanation: In ferns, the roots that emerge from the rhizome are known as 'adventitious roots.' These roots develop from structures other than the primary root, such as stems or rhizomes, allowing the plant to anchor itself and absorb nutrients effectively. The rhizome, a horizontal underground stem, generates both roots and fronds (the leaves of ferns). This adaptation is essential for the fern's survival and propagation. Other options, such as pneumatophores and rhizoids, are not applicable to ferns as they belong to different plant categories or serve different purposes.

Q41. Pigment combination of a carotenoid is:

• A. Blue, green, brown, or red
• B. Orange, yellow, blue, or brown
• C. Yellow, orange, red, or brown✓
• D. Blue, red, orange, or brown

Explanation: Carotenoids are accessory pigments found in plants that include colors such as yellow, orange, red, and brown. They are crucial in photosynthesis because they absorb light energy and protect chlorophyll from photo-damage. The other options are incorrect as they include colors like blue and green, which are typically associated with chlorophyll pigments, not carotenoids.

Q42. The study of fishes is called:

• A. Ornithology
• B. Ichthyology✓
• C. Herpetology
• D. Ethology

Explanation: The correct answer is Ichthyology, which is the branch of zoology dedicated to the study of fishes. This field explores various aspects of fish biology, including their structure, function, and ecological roles. The other options represent different branches of zoology: Ornithology focuses on birds, Herpetology on amphibians and reptiles, and Ethology on animal behavior. None of these specifically address the study of fishes.

Q43. D.N.A of bacterium is:

• A. Haploid, single stranded, coiled
• B. Diploid, double stranded, coiled
• C. Haploid, double stranded, coiled✓
• D. Diploid, single stranded, coiled

Explanation: Bacterial DNA is characterized by being a single, circular, double stranded molecule that is tightly coiled to fit within the cell. This DNA forms the bacterial chromosome, and because bacteria have only one chromosome, they are haploid. Option C is correct because it accurately describes the nature of bacterial DNA. Option A is incorrect as bacterial DNA is not single stranded. Option B is incorrect because bacteria are not diploid; they only have one chromosome. Option D is incorrect as bacterial DNA is not single stranded and bacteria are not diploid.

Q44. Chiroptera are:

• A. Flying mammals✓
• B. Flesh-eating mammals
• C. Hoofed mammals
• D. Aquatic mammals

Explanation: Chiroptera, commonly known as bats, are the only flying mammals. Their wings are composed of a thin membrane of skin supported by elongated finger bones, enabling them to achieve powered flight. This adaptation distinguishes them from other mammals that might glide but cannot sustain flight. The incorrect options include: flesh-eating mammals, which are not an accurate general classification as most bats eat insects or fruits; hoofed mammals, which have hooves unlike the bat's wing structure; and aquatic mammals, which are adapted to life in water, in contrast to the terrestrial and aerial adaptations of bats.

Q45. The swallowing process is regulated by:

• A. Throat
• B. Pharynx
• C. Medulla oblongata✓
• D. Stomach

Explanation: The swallowing process is primarily regulated by the medulla oblongata, which is part of the brainstem. It is responsible for the involuntary reflex actions required in swallowing, coordinating the actions of the tongue and muscles in the pharynx and esophagus. While the pharynx is involved in the movement of the bolus, the regulation of the swallowing reflex itself is controlled by the medulla oblongata. The throat and stomach play roles in the physical movement and digestion of food, respectively, but do not regulate the swallowing process.

Q46. World-wide, mortality rate per annum due to AIDS is more than:

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

Explanation: AIDS is a major global health concern, with mortality rates exceeding three million per year worldwide. While efforts continue in prevention and treatment, the disease still claims many lives. Option A (One million) and Option B (Two million) underestimate the global impact of AIDS. Option D (Five million) overestimates the annual mortality rate, which is why Option C (Three million) is the most accurate representation of the current global situation.

Q47. "Portuguese-man of war" is the:

• A. Desert-snake
• B. Coelenterate✓
• C. A big-reptile
• D. Black-forest monkey

Explanation: The Portuguese-man-of-war is a coelenterate, a marine invertebrate belonging to a group that includes jellyfish and sea anemones. It is a colonial organism composed of specialized polyps that perform different functions such as buoyancy, prey capture, and reproduction. Unlike reptiles, which are vertebrates with scales, or monkeys, which are mammals, the Portuguese-man-of-war is a venomous coelenterate capable of delivering a painful sting. It is not related to desert snakes or any type of mammal.

Q48. Rootless, stem-less and leafless plants are:

• A. Liverworts✓
• B. Mosses
• C. Psilopsida
• D. Onion

Explanation: The correct answer is Liverworts. Liverworts are the simplest form of non-vascular plants and lack true roots, stems, or leaves. They attach to surfaces using rhizoids and reproduce through spores.Mosses, while also non-vascular, have a more complex structure with a pseudo-stem and small leaves. Psilopsida, on the other hand, are primitive vascular plants, and onions are fully developed vascular plants with a distinct structure and seed-based reproduction.

Q49. Amphibians generally have three chambers in their hearts. What type of chambers they are?

• A. One ventricle, two atria✓
• B. Two ventricles, one atrium
• C. One ventricle, one atrium
• D. One ventricle, one atrium, one sinus venosus

Explanation: Amphibians typically have a heart with three chambers, which includes one ventricle and two atria. This structure allows for some mixing of oxygenated and deoxygenated blood, which is suitable for their metabolism and lifestyle. In contrast, the hearts of birds and mammals have four chambers (two atria and two ventricles) to completely separate oxygenated and deoxygenated blood. The incorrect options either suggest an incorrect number of chambers or misidentify the sinus venosus as a primary chamber.

Q50. Release of calcium from bone in to blood is controlled by:

• A. Parathormone (PTH)✓
• B. Calcitonin
• C. Thyroxine
• D. Both (a) & (b)

Explanation: The release of calcium from bone into the blood is controlled by parathyroid hormone (PTH). PTH is produced by the parathyroid glands and is responsible for raising blood calcium levels. It does so by stimulating osteoclasts to break down bone tissue, releasing calcium into the bloodstream. Additionally, PTH enhances calcium reabsorption in the kidneys and promotes the activation of vitamin D, which further aids in calcium absorption from the diet.Calcitonin, on the other hand, serves to lower blood calcium levels by encouraging calcium deposition in bones and increasing its excretion through the kidneys. Thyroxine does not play a direct role in calcium regulation. Therefore, the correct answer is parathormone.

Q51. That 1st field trial of genetically engineered plants occurred in France and USA in:

• A. 1980
• B. 1982
• C. 1984
• D. 1986✓

Explanation: The first field trials of genetically engineered plants were conducted in 1986 in France and the USA, focusing on tobacco plants engineered for herbicide resistance. This was a pivotal moment in the history of agricultural biotechnology, laying the groundwork for future developments in genetically modified organisms (GMOs). The incorrect options (1980, 1982, 1984) represent years when biotechnology was still in its experimental and developmental phases, and field trials had not yet been implemented on a large scale.Additionally, these trials paved the way for subsequent advancements, such as the release of the ice-minus strain of Pseudomonas syringae in 1987, commercialization of transgenic plants in China in 1992, and the approval of genetically modified foods like the Flavr Savr tomato in 1994.

Q52. Sense of taste is called:

• A. Gustation✓
• B. Tactician
• C. Nociception
• D. Olfaction

Explanation: The correct answer is Gustation. This term is used to describe the process of detecting taste through taste buds located on the tongue, which respond to chemical substances in food and drink.The option Tactician is unrelated to sensory perception and pertains to strategy or planning. Nociception involves the detection of pain by the nervous system, not related to taste. Olfaction is the term for the sense of smell, a separate sensory system from taste.

Q53. Basidiocarps are developed by:

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

Explanation: The correct answer is secondary mycelium. This stage occurs after the primary mycelium has established itself and involves the fusion of cells from two different primary mycelia, leading to a dikaryotic state. This dikaryotic secondary mycelium is capable of forming basidiocarps, which are the fruiting bodies of basidiomycete fungi. Primary mycelium is important for initial growth and nutrient absorption but does not lead to fruiting body formation. Tertiary mycelium refers to further structural developments in some fungi, but is not responsible for basidiocarp formation. Quaternary mycelium is not a recognized term in mycology.

Q54. Outer wall of guard cells is:

• A. Thin & elastic✓
• B. Thick & elastic
• C. Thin & non elastic
• D. Thick & non elastic

Explanation: Guard cells are pairs of specialized epidermal cells that work to control excessive water loss, closing on hot, dry, or windy days and opening when conditions are more favorable for gas exchange. The inner wall of a guard cell is thicker than the outer wall. When the guard cell is filled with water and it becomes turgid, the outer wall balloons outward, drawing the inner wall with it and causing the stomata to enlarge. The outer wall of guard cells is thin and elastic.

Q55. Eating of high carbohydrate food are signs and symptoms of:

• A. Obesity
• B. Bulimia nervosa✓
• C. Dyspepsia
• D. Anorexia nervosa

Explanation: Bulimia nervosa is characterized by recurrent episodes of binge eating, wherein individuals consume large amounts of food, often high in carbohydrates, in a short period. This is usually followed by inappropriate compensatory behaviors to prevent weight gain, such as vomiting, fasting, or excessive exercise. Unlike bulimia, obesity refers to excess body weight due to fat, without the episodic eating pattern. Dyspepsia is a term for indigestion, unrelated to specific eating patterns. Anorexia nervosa involves food restriction and fear of weight gain, contrasting with the binge eating seen in bulimia nervosa.

Q56. In case of immunity, the first line of body defense is:

• A. Macrophages
• B. Lymphocytes
• C. Blood cells
• D. Skin✓

Explanation: The correct answer is skin. The skin acts as a physical barrier, preventing harmful pathogens from entering the body. It is the first line of defense in the immune system. The skin also hosts beneficial bacteria that help maintain a balance, preventing the growth of harmful microorganisms.Macrophages operate in the second line of defense, dealing with pathogens that have bypassed the first line. Lymphocytes are part of the adaptive immune system, responding to specific invaders after they have breached initial defenses. Blood cells, while crucial for various bodily functions, are not involved in the initial immune barrier.

Q57. Transport of organic solutes from the source of assimilation to the source of sink is:

• A. Transportation
• B. Transduction
• C. Translocation✓
• D. Transformation

Explanation: The correct answer is translocation. This process specifically refers to the movement of organic solutes such as sugars and amino acids through the phloem from the source, where they are synthesized, to the sink, where they are consumed or stored. The movement is driven by a pressure gradient created by the differential concentration of solutes between the source and the sink.Option A, 'Transportation,' is too general as it does not specifically describe the biological process in plants. Option B, 'Transduction,' refers to signaling and not solute movement. Option D, 'Transformation,' relates to genetic material transfer in bacteria and is unrelated to the movement of solutes in plants.

Q58. The percentage of symbolic association by Ascomycota is more than:

• A. 50%
• B. 40%✓
• C. 20%
• D. 30%

Explanation: Ascomycota, also known as sac fungi, are known for their ability to form symbiotic associations, particularly in the form of lichens. These fungi make up a significant portion of lichenized fungi, with studies indicating that over 40% of Ascomycota species engage in such symbiotic relationships. This makes option B the correct answer. Options A, C, and D are incorrect because they either overestimate or underestimate the percentage of symbolic association by Ascomycota.

Q59. Delayed wound healing is caused by deficiency of:

• A. Zinc (Zn)✓
• B. Iron (Fe)
• C. Cobalt (Co)
• D. Manganese (Mn)

Explanation: Zinc (Zn) deficiency is directly linked to delayed wound healing because zinc is integral to the processes of collagen synthesis and cell proliferation, which are crucial for repairing and closing wounds. Without sufficient zinc, these critical processes are disrupted, resulting in impaired healing.Iron (Fe) deficiency primarily causes anemia due to its role in hemoglobin formation, affecting overall oxygen transport but not specifically wound healing. Cobalt (Co) is essential for vitamin B12 function, influencing blood and nerve health, but it does not directly impact the healing process of wounds. Manganese (Mn) supports enzymatic activities and bone health, and while it plays a role in tissue repair, its deficiency is not a common cause of delayed wound healing.

Q60. Which of the following statements is correct?

• A. H3PO3 is dibasic and reducing✓
• B. H3PO3 is tribasic and reducing
• C. H3PO3 is tribasic and non-reducing
• D. H3PO3 is dibasic and non-reducing

Explanation: H3PO3 is correctly identified as dibasic because it has two -OH groups that can release hydrogen ions. Additionally, the presence of a P-H bond in its structure allows it to donate hydrogen atoms, making it a reducing agent. The incorrect options either misidentify it as tribasic or incorrectly label it as non-reducing.

Q61. Which of the following is correct about speed of nerve impulse:

• A. Thicker the nerve fiber-less resistance to flow of current-faster the nerve impulse.✓
• B. Thicker the nerve fiber-more resistance to flow of current-slower the nerve impulse
• C. Thinner the nerve fiber-less resistance to flow of current-slower the nerve impulse
• D. None of the above

Explanation: The correct answer is that thicker nerve fibers have less resistance to the flow of current, leading to faster nerve impulse transmission. This is primarily because thicker fibers are typically more myelinated. Myelin acts as an insulator, reducing resistance and increasing conduction speed. In contrast, thinner fibers have less myelin and more resistance, resulting in slower impulse transmission. This explains why the other options are incorrect, as they either incorrectly state the relationship between fiber thickness, resistance, and impulse speed, or deny the presence of a correct statement.

Q62. Archaea live in both extreme and moderate environments those living in extreme condition are called:

• A. Extremophile✓
• B. Methanogen
• C. Extremophyte
• D. Extremogeus

Explanation: The correct term for organisms that live in extreme environments is extremophile. These organisms have adapted to survive in harsh conditions such as extreme heat, cold, acidity, or salinity, which would be detrimental to most other life forms.The other options are incorrect for the following reasons:Methanogen: While methanogens are a type of extremophile, the term specifically refers to those archaea that produce methane, and not all extremophiles are methanogens.Extremophyte: This term inaccurately combines concepts and is not used in scientific contexts to describe extremophiles.Extremogeus: This is not a recognized term and appears to be a misspelling or misunderstanding of 'extremophile'.

Q63. In a cricket match 500 spectators are counted one by one. How many significant figures will be there in the final result?

• A. 0
• B. 1
• C. 2
• D. 3✓

Explanation: The number 500 is a whole number and has three significant figures: the digit '5' and the two trailing zeros. Trailing zeros in a whole number without a decimal point are considered significant because they indicate the precision of the count. This is why option D is correct. Option A is incorrect because significant figures cannot be zero for a non-zero number. Option B is incorrect because '500' does not consist of only one significant digit. Option C is also incorrect because the zeros in '500' are significant, not just placeholders.

Q64. The botanical name of deadly nightshade is:

• A. Atropa belladonna✓
• B. Taxus baccata
• C. Narcissus spp.
• D. Both (a) & (b)

Explanation: The correct answer is Atropa belladonna, which is the scientific name for deadly nightshade. This plant is part of the Solanaceae family, known for containing potent alkaloids such as atropine. The berries and foliage are highly toxic and can be fatal if ingested.Taxus baccata refers to the yew tree, which is toxic due to taxine alkaloids but is not related to the nightshade family.Narcissus spp. are daffodils, which are not poisonous in the same way and are unrelated to the nightshade family.The option 'Both (a) & (b)' is incorrect as it combines two distinct plants that are not both deadly nightshade.

Q65. Hormone inhibin is produced by:

• A. Hypothalamus
• B. Pituitary gland
• C. Prostate
• D. Sertoli cells✓

Explanation: The correct answer is Sertoli cells. Inhibin is produced by Sertoli cells within the testes and is part of the transforming growth factor-beta (TGF-β) superfamily. It plays a key role in regulating spermatogenesis by providing negative feedback to the anterior pituitary gland to suppress FSH secretion, preventing excessive sperm production. Additionally, inhibin is involved in ovarian function regulation. The hypothalamus, pituitary gland, and prostate do not produce inhibin; their roles are distinct in the endocrine system.

Q66. All of the following are micronutrients accept:

• A. Iron
• B. Chlorine
• C. Copper
• D. Potassium✓

Explanation: The correct answer is potassium. Potassium is classified as a macromineral, not a micronutrient. Macrominerals, including potassium, calcium, and magnesium, are required by the body in larger quantities compared to micronutrients. Micronutrients, such as iron, chlorine, and copper, are essential but needed in smaller amounts. These micronutrients play vital roles in bodily functions, but their required intake is significantly less than that of macrominerals like potassium.

Q67. Auxin travels by diffusion towards:

• A. Shoot
• B. Flowers
• C. Leaves
• D. Base of the plant✓

Explanation: Auxin is a plant hormone that is primarily produced in the shoot tips and young leaves. It travels downwards through the plant by the process of diffusion and active transport, primarily moving towards the base of the plant. This movement is crucial for processes such as cell elongation and root development. The other options are incorrect because auxin does not specifically travel towards the shoot, flowers, or leaves, but rather it moves downwards to the base for broader distribution and effect.

Q68. Reptiles flourished in _ period.

• A. Jurassic
• B. Mesozoic
• C. Metazoic
• D. Both (a) & (b)✓

Explanation: The correct answer is "Both (a) & (b)". Reptiles flourished during the Mesozoic era, known as the "Age of Reptiles", which includes the Triassic, Jurassic, and Cretaceous periods. The Jurassic period is a part of this era and was a time of significant reptile diversity, notably for dinosaurs. Although the Jurassic period saw a peak in reptilian diversity, it is just one part of the Mesozoic era, which collectively represents the flourishing of reptiles. The option 'Metazoic' is incorrect as it is not a recognized geological term, making it a distractor.

Q69. Which of the following is non-steroidal hormone?

• A. Cortisol
• B. Testosterone
• C. Insulin✓
• D. Aldosterone

Explanation: Insulin is a non-steroidal hormone, distinct from steroid hormones which are derived from cholesterol and are fat-soluble. Instead, insulin is a protein hormone, water-soluble, and functions by binding to receptors on the cell membrane to exert its effects. In contrast, cortisol, testosterone, and aldosterone are steroid hormones, characterized by their ability to pass through cell membranes and interact with receptors inside the cell. These differences in solubility and receptor interaction are key to distinguishing between steroidal and non-steroidal hormones, confirming that Insulin is the correct answer.

Q70. Stop codons are:

• A. UAA,UAG,UGA✓
• B. UGC,UCG,AAA
• C. UUG,UCG,UCA
• D. UAA,UGC,UCA

Explanation: Stop codons are codons (triplets of nucleotides) in messenger RNA (mRNA) that signal the termination of protein synthesis. Out of 64 codons, there are three stop codons: UAA, UAG, and UGA. These codons do not code for any amino acids hence, are known as nonsense codons. When a ribosome reaches a stop codon, it releases the amino acid chain that it has been building. This signals the end of protein synthesis.Stop codons are important for ensuring that proteins are the correct length. If a protein is not the correct length, it may not be functional. REMEMBER THEM ASUGA[ u go away]UAA [ u are away]UAG [ u are gone]

Q71. The tissue culture method occur in the following sequence:

• A. Sterilization -> media preparation -> inoculation -> callus development -> plantlets
• B. Media preparation -> sterilization -> inoculation -> callus development -> plantlets
• C. Media preparation -> inoculation -> sterilization -> callus development -> plantlets✓
• D. Inoculation -> sterilization -> media preparation -> callus development -> plantlets

Explanation: The correct sequence of the tissue culture method is: Media preparation -> Inoculation -> Sterilization -> Callus development -> Plantlets. Media preparation is the first step where nutrients are provided for growth. Inoculation involves introducing the inoculum into the prepared media. Sterilization is critical to ensuring a contaminant-free environment, which is necessary before callus development. Callus development involves the growth of undifferentiated cells, eventually leading to the formation of plantlets. Other options are incorrect because they misplace the crucial steps in the process.

Q72. A condition in which the artery is thickened and blocked by cholesterol is called;

• A. Arteriosclerosis
• B. Atherosclerosis✓
• C. Thrombosis
• D. Embolism

Explanation: Atherosclerosis is a condition that specifically involves the buildup of cholesterol and plaque on the artery walls, leading to thickening and potential blockage. This process can significantly narrow the arteries, impeding blood flow and leading to serious health issues such as heart disease and stroke.While arteriosclerosis refers to the general stiffening and thickening of arteries, it doesn't specifically denote cholesterol buildup as a cause. Thrombosis involves blood clot formation, and embolism involves the movement of a clot to a different location, neither of which are directly caused by cholesterol accumulation.

Q73. Oligosaccharides are involved in the formation of:

• A. Secreted proteins
• B. Blood clotting factors
• C. Antibodies
• D. All of the above✓

Explanation: The correct answer is All of the above because oligosaccharides are involved in the modification and functionality of secreted proteins, blood clotting factors, and antibodies. In secreted proteins, oligosaccharides assist in folding and stability, crucial for their extracellular roles. For blood clotting factors, they ensure proper interaction and stabilization necessary for clot formation. Antibodies utilize oligosaccharides to enhance antigen binding and immune system activation. Thus, oligosaccharides are essential for the proper function of a wide range of proteins.

Q74. A slowly progressive disease of the brain that is characterized by the impairment of memory and eventually by disturbance in reasoning, planning, language and perception is one of the following?

• A. Alzheimer's disease✓
• B. Meningitis
• C. Cerebrovascular accident (CVA)
• D. Malignant

Explanation: The correct answer is Alzheimer's disease. Alzheimer's disease is a chronic neurodegenerative disease that typically starts slowly and progressively worsens. It primarily affects memory and other important cognitive functions such as reasoning, language, and perception.Meningitis is incorrect because it is an acute inflammation of the protective membranes covering the brain and spinal cord, usually caused by an infection.Cerebrovascular accident, or stroke, is incorrect because it is a sudden, not progressive, interruption of blood flow to the brain, often resulting in immediate and severe neurological symptoms.Malignant is incorrect as it refers to cancerous growths and is not applicable to a chronic neurodegenerative disease like Alzheimer's.

Q75. The most abundant lymphocytes are:

• A. C–cells
• B. A & B cells
• C. B & C cells
• D. B & T cells✓

Explanation: The most abundant lymphocytes are B and T cells, which play critical roles in the immune system. B cells are responsible for producing antibodies, aiding in the identification and neutralization of pathogens. T cells have diverse roles, including attacking infected or cancerous cells and coordinating the immune response. Other options mention C-cells, which are not lymphocytes but rather thyroid cells, and A cells, which are not recognized in the context of lymphocytes.

Q76. The number of cortical nephrons are:

• A. 70–80%
• B. 80–90%✓
• C. 60–70%
• D. 60–80%

Explanation: Approximately 80%-90% of all nephrons in the human kidney are cortical nephrons. These nephrons are characterized by their glomeruli being located in the outer cortex of the kidney and having relatively short loops of Henle that do not extend deep into the medulla. This makes them the most abundant type of nephrons in the kidney. The other options underestimate the proportion of cortical nephrons in the kidney.

Q77. The outer tissue of cambium develops in to:

• A. Xylem
• B. Phloem✓
• C. Cortex
• D. Epidermis

Explanation: The cambium is a layer of actively dividing cells in plants that contributes to secondary growth by producing new cells. On its outer side, the cambium generates phloem, which is essential for transporting sugars and nutrients throughout the plant. In contrast, xylem forms on the inner side of the cambium and is responsible for water and mineral transport. The cortex is a separate tissue, formed from the primary meristem, and the epidermis originates from the apical meristem, not the cambium.

Q78. The 1st symptom of Leaf curl disease of cotton infection appear within:

• A. 1 – 2 weeks
• B. 2 – 3 weeks✓
• C. 3 – 4 weeks
• D. 4 – 5 weeks

Explanation: The correct answer is 2 – 3 weeks. Leaf curl disease symptoms in cotton typically become visible within this timeframe due to the pathogen's incubation period. Options 1 – 2 weeks and 3 – 4 weeks are incorrect because the symptoms generally do not manifest that quickly or take that long to appear. Option 4 – 5 weeks is also too late for the initial appearance of symptoms. Recognizing the typical progression of plant diseases can help determine the correct answer.

Q79. The mutation that occurs in an egg or sperm cell, or those that occur just after fertilization, are called _ mutation.

• A. New
• B. De novo✓
• C. Drift
• D. Both (a) & (b)

Explanation: The correct answer is De novo mutation. These mutations occur in the germ cells or immediately after fertilization and are not inherited from the parents. The term 'de novo' means 'from the new', highlighting their origin as a new genetic change. Option A, 'New', is a general term and not specific enough. Option C, 'Drift', refers to genetic drift and not the type of mutation described. Option D incorrectly combines options that are not both correct.

Q80. The hydrated cations of first transition series that imparts a blue color:

• A. Cr2+, Co2+, Cu2+✓
• B. Cu2+, Zn2+, Ti4+
• C. Ti3+, Zn2+, Cu2+
• D. Cr3+, Ti4+, Cu2+

Explanation: The correct answer is Option A: Cr2+, Co2+, Cu2+. These transition metal ions possess unpaired d-electrons, allowing for d-d electronic transitions. When light passes through a solution containing these ions, specific wavelengths are absorbed, and others are emitted, giving rise to their characteristic blue color. Option B is incorrect because Zn2+ has a fully filled d-orbital, preventing d-d transitions. Option C is incorrect because Zn2+ does not exhibit color due to its filled d-orbital, even though Ti3+ and Cu2+ can be colored. Option D is incorrect because Ti4+ lacks d-electrons, thus cannot contribute to color, despite Cr3+ and Cu2+ being potentially colored.

Q81. Select the correct order of the acids strength?

• A. CH3COOH >> CHCl2COOH > CH2ClCOOH
• B. CHCl2COOH > CH2ClCOOH > CH3COOH✓
• C. CH3COOH > CHCl2COOH > CH2ClCOOH
• D. CHCl2COOH >> CH2COOH > CH2ClCOOH

Explanation: The acidity of carboxylic acids is influenced by the presence of electron-withdrawing groups. These groups stabilize the carboxylate ion by delocalizing the negative charge via inductive effects, thereby increasing acidity. In the given options, CHCl2COOH is the strongest acid because it has two chlorine atoms, which significantly withdraw electrons, enhancing the acid strength. CH2ClCOOH, with one chlorine, is less acidic than CHCl2COOH but more acidic than CH3COOH, which lacks electron-withdrawing groups and is thus the weakest acid. Option B correctly identifies this trend, while the other options incorrectly order the acids or introduce non-existent compounds.

Q82. Which is not correct about the manufacture of ammonia by Haber – Process? The break opening of the nitrogen triple bond (N = N) to form N2H2 in first step of the reaction is taken as:

• A. Very difficult step
• B. Highly unstable product
• C. Highly endothermic✓
• D. None of the above

Explanation: The Haber process involves the synthesis of ammonia (NH3) from nitrogen (N2) and hydrogen (H2) gases. The forward reaction is exothermic, meaning it releases heat. The breaking of the nitrogen triple bond (N≡N) to form N2H2 is not highly endothermic in this context. Instead, the entire process moves towards equilibrium and is managed to maximize ammonia production. The incorrect option is C, as the forward reaction in the Haber process is exothermic, contrary to what the term 'highly endothermic' would suggest.

Q83. Carbon monoxide can be converted by hydrogenolysis to alkanes by the process known as:

• A. Contact process
• B. Fischer-Tropsch (FT) process✓
• C. Fermentation process
• D. Haber-Bosch process

Explanation: The Fischer-Tropsch process is the correct answer because it involves the conversion of carbon monoxide and hydrogen into hydrocarbons, including alkanes, through a series of chemical reactions that require a catalyst. This process is a type of hydrogenolysis, where hydrogen is used to break bonds and form new products. The other options are unrelated to the conversion of carbon monoxide into alkanes: the Contact process produces sulfuric acid, the Fermentation process converts sugars into alcohol or acids, and the Haber-Bosch process synthesizes ammonia from nitrogen and hydrogen.

Q84. How much phosphorus is required by an adult man per day?

• A. 500 mg
• B. 400 mg
• C. 800 mg✓
• D. 1800 mg

Explanation: Phosphorus is crucial for numerous bodily functions, including the formation of bones and teeth, and it plays a role in how the body uses carbohydrates and fats. The recommended daily intake for phosphorus for a healthy adult is between 800mg and 1200mg. Option C, 800 mg, falls within this range, making it the correct answer. Options A and B (500 mg and 400 mg) are below the recommended intake and could potentially lead to deficiency, while Option D (1800 mg) is above the recommended range and could pose health risks if consumed regularly.

Q85. How many sodium ions (Na+) will be pumped out, when IO-postassium ions (K+) are transported inward of resting member potential.

• A. 5
• B. 10
• C. 15✓
• D. 20

Explanation: The Na+/K+ pump, also known as Na+/K+-ATPase, is crucial in maintaining the resting membrane potential of cells by actively transporting ions against their gradients. It moves 3 sodium ions out of the cell for every 2 potassium ions it brings in. For the inward transport of 10 potassium ions, the pump will export 15 sodium ions to maintain this specific ratio. Options A, B, and D do not reflect this ratio and therefore are incorrect.

Q86. At absolute zero the molecules of hydrogen gas will have:

• A. Only translational motion
• B. Only vibrational motion
• C. Only rotational motion
• D. All motion is ceased✓

Explanation: At absolute zero, which is 0 Kelvin or -273.15°C, all molecular motion ceases. This is because absolute zero represents the lowest possible temperature, where thermal energy is nonexistent, thus halting all forms of motion, including translational, vibrational, and rotational. This is why option D is correct. The other options are incorrect because they suggest that some form of motion still occurs, which is not the case at absolute zero.

Q87. A dilute hydrochloric acid is added to a flask containing time stone a gas is produced which is dissolved in time water in a test tube a white precipitate is formed the precipitate is of:

• A. CaSO4
• B. CaCO3✓
• C. CaCl2
• D. MgCO3

Explanation: In this reaction, dilute hydrochloric acid reacts with a carbonate compound, releasing carbon dioxide gas (CO2). This gas dissolves in water to form carbonic acid (H2CO3), which subsequently reacts with calcium ions to precipitate calcium carbonate (CaCO3), a white solid. This explains why CaCO3 is the correct answer. The other options are incorrect because:CaSO4: Forms with sulfuric acid, not hydrochloric acid.CaCl2: Soluble in water, does not precipitate.MgCO3: Although it can form a precipitate, it does not match the described reaction sequence.

Q88. 2XeF6 + SiO2 --> 2XeOF4 + SiF4 Consider the above chemical reaction. If 122.6 g of XeF6 reacts with 60 g of SiO2 to form the products. Select the limiting reagent and amount of SiF4 formed: (XeF6 245.3 amu, SiO2 = 60 amu, SiF4 = 104 amu)

• A. XeF6, 25.5 g✓
• B. SiO2, 26 g
• C. XeF6, 52 g
• D. SiO2, 52 g

Explanation: To solve this problem, first calculate the moles of each reactant. For XeF6, with a molar mass of 245.3 g/mol, 122.6 g is equivalent to 0.4986 moles. For SiO2, with a molar mass of 60 g/mol, 60 g is equivalent to 1 mole. The balanced equation shows that 2 moles of XeF6 react with 1 mole of SiO2. Since we have fewer moles of XeF6 compared to the stoichiometric requirement, XeF6 is the limiting reagent.Knowing this, we can calculate the amount of product formed. According to the stoichiometry of the reaction, 2 moles of XeF6 produce 1 mole of SiF4. Therefore, 0.4986 moles of XeF6 will produce 0.2493 moles of SiF4. The mass of SiF4 produced is 0.2493 moles multiplied by its molar mass of 104 g/mol, resulting in 25.5 g of SiF4.Therefore, the correct answer is that XeF6 is the limiting reagent, and 25.5 g of SiF4 is formed.The other options are incorrect because they either misidentify the limiting reagent or incorrectly calculate the amount of SiF4 formed.

Q89. Ethanal reacts with CH3CH2Mg Br the product formed is:

• A. CH3CH2OH
• B. CH3CH2CHO
• C. CH3CH(OH)CH2CH3✓
• D. CH3CH2CH2OH

Explanation: The correct answer is CH3CH(OH)CH2CH3. In this Grignard reaction, the ethyl group from the Grignard reagent (CH3CH2MgBr) adds to the carbonyl carbon of ethanal (CH3CHO), forming a secondary alcohol after hydrolysis. The process involves the nucleophilic attack of the Grignard reagent on the carbonyl carbon, followed by protonation during the workup step. Options A, B, and D are incorrect as they either represent unreacted starting materials or products with incorrect structures not formed in this reaction.

Q90. Which is not true about Grignard reagent?

• A. They are highly reactive compounds.
• B. They are very stable compounds and can be isolated easily.✓
• C. They have synthetic importance.
• D. They are represented by the general formula RMgX.

Explanation: The correct answer is They are very stable compounds and can be isolated easily. This statement is false because Grignard reagents are highly reactive and sensitive to moisture and air, which makes them unstable and difficult to isolate. They are usually prepared and used immediately in situ. Conversely, the other options are true: Grignard reagents are highly reactive, important for synthetic applications, and are represented by the formula RMgX.

Q91. Choose reaction that is not correct?

• A. Option A: Acetic acid reacts with sodium to form sodium acetate and hydrogen gas.
• B. Option B: Acetic acid reacts with ethanol in the presence of sulfuric acid to form ethyl acetate and water.
• C. Option C: Acetic acid reacts with phosphorus pentoxide to form acetic anhydride.
• D. Option D: Acetic acid reacts with ammonia to form acetyl chloride and water.✓

Explanation: The correct answer is Option D. Acetic acid does not react with ammonia to form acetyl chloride and water; instead, it usually forms ammonium acetate. Options A, B, and C describe well-established reactions: A is the reaction with sodium forming sodium acetate, B is esterification with ethanol forming ethyl acetate, and C is dehydration with phosphorus pentoxide forming acetic anhydride.

Q92. XYZ are the elements in the same short period of the periodic table the oxide of X is amphoteric the Exide of Y is basic and the Exide of Z is acidic what is the order of increasing atomic number for these elements?

• A. XYZ
• B. XZY
• C. YXZ✓
• D. ZXY

Explanation: In a given period of the periodic table, the nature of oxides changes from basic to amphoteric to acidic as you move from left to right. This corresponds to increasing atomic numbers. Therefore, the correct order of increasing atomic number for these elements is Y (basic oxide), X (amphoteric oxide), Z (acidic oxide), making the sequence YXZ. Option C is correct. The other options do not follow this trend, thereby making them incorrect.

Q93. In which of the following reaction hydrogen acts as oxidizing agent.

• A. H2 + Cl2 --> 2HCl
• B. C2H4 + H2 --> C2H6
• C. 2Na + H2 --> 2NaH✓
• D. N2 + 3H2 --> 2NH3

Explanation: In the correct reaction, 2Na + H2 --> 2NaH, sodium (Na) is oxidized, as it loses electrons to form Na+, while hydrogen (H2) is reduced to form H−. Therefore, in this reaction, H2 acts as an oxidizing agent by gaining electrons. In the other reactions, H2 is either oxidized or acts as a reducing agent.

Q94. The correct order of the reactivity of hydrocarbon given below is:

• A. C2H4 > C2H2 > C6H6✓
• B. C6H6 > C2H4 > C2H2
• C. C2H4 > C2H4 > C6H6
• D. C2H2 > C6H6 > C2H4

Explanation: In electrophilic addition reactions, the reactivity order is C2H4 (alkene) > C2H2 (alkyne) > C6H6 (benzene). Alkenes are more reactive due to the relative ease of forming a carbocation intermediate. Alkynes, though reactive, are less so than alkenes because of the stronger π bonds. Benzene is least reactive in addition reactions owing to its aromatic stability and resonance, making it favor substitution reactions over addition.

Q95. How many oxygen atoms are present in 278g of Hydrated Ferrous Sulphate?(FeSO4.7Hz 0 = 278 any)

• A. 6.023 x 1023
• B. 6.525 x 1024✓
• C. 2.408 x 1023
• D. 6.023 x 1022

Explanation: The chemical formula for hydrated ferrous sulfate is FeSO4·7H2O, which includes 4 oxygen atoms from the sulfate ion (SO4) and 7 oxygen atoms from the 7 water molecules (7H2O), resulting in a total of 11 oxygen atoms per formula unit.Multiplying the number of oxygen atoms by Avogadro's number (6.023 x 1023) gives the total number of oxygen atoms in one mole of the compound: 11 x 6.023 x 1023 = 6.625 x 1024 oxygen atoms.Thus, Option B is correct. Options A, C, and D do not account for the correct total number of oxygen atoms in the compound when multiplied by Avogadro's number, leading to incorrect results.

Q96. The compound Aldehyde hydrazone is:

• A. A compound formed by the reaction of an aldehyde with hydrazine.✓
• B. A compound formed by the reaction of an aldehyde with water.
• C. A compound formed by the reaction of an aldehyde with an amine.
• D. A compound formed by the reaction of an aldehyde with hydrogen cyanide.

Explanation: Aldehyde hydrazones are organic compounds derived from the reaction of aldehydes with hydrazine (NH2-NH2) or its derivatives. This reaction involves the addition of hydrazine across the carbonyl group of the aldehyde, resulting in the formation of a hydrazone with the general structure RH > CH = N-NH2, where RH represents the organic group attached to the carbonyl carbon of the aldehyde.Option A is correct as it accurately describes this reaction and the resulting compound. Option B is incorrect because a reaction with water forms a hydrate. Option C is incorrect because an aldehyde reacting with an amine forms an imine. Option D is incorrect because a reaction with hydrogen cyanide forms a cyanohydrin.

Q97. Which is the correct IUPAC name of the compound given below?

• A. Acetophenon
• B. Phenylethanone✓
• C. Phenyl ethanal
• D. Phenylacetate

Explanation: The correct IUPAC name for the compound is 'Phenylethanone'. This compound is a ketone with a phenyl group attached to the carbonyl group, which replaces one of the methyl groups in acetone. Option B is correct because it accurately represents the structure of the compound. Option A 'Acetophenon' is incorrect due to a spelling error, as the correct term is 'Acetophenone'. Option C, 'Phenyl ethanal', refers to an aldehyde, not a ketone. Option D, 'Phenylacetate', describes an ester, which does not match the ketone structure of the given compound.

Q98. Chromium compounds in which oxidation state of chromium is 2+ behaves as a:

• A. Strong oxidizing agent
• B. Strong reducing agent✓
• C. Very weak oxidizing agent
• D. Very weak reducing agent

Explanation: The correct answer is that chromium compounds in which the oxidation state of chromium is 2+ behave as strong reducing agents. This is due to their ability to easily donate electrons, thereby reducing other substances and becoming oxidized themselves to higher oxidation states such as +3, +4, or +6.Option A, a strong oxidizing agent, is incorrect because chromium in the +2 state is more likely to be oxidized than to oxidize other substances. Option C, a very weak oxidizing agent, is incorrect for similar reasons, as it downplays the reducing capability of chromium(II). Option D, a very weak reducing agent, underestimates the reducing strength of chromium in this state, which can effectively donate electrons in chemical reactions.

Q99. Primary amines on treatment with alkyl halide yield;

• A. Secondary amine
• B. Tertiary amine
• C. Quaternary ammonium salt
• D. Mixture of (a), (b) & (c)✓

Explanation: When primary amines are treated with alkyl halides, they undergo a series of nucleophilic substitution reactions. Initially, secondary amines are formed. If the reaction continues, tertiary amines can be generated, and with further reaction, quaternary ammonium salts are produced. Thus, the process often results in a mixture of secondary, tertiary amines, and quaternary ammonium salts, depending on the reaction conditions and stoichiometry. The mixture is due to the stepwise alkylation of the amine.Option A is incorrect because the reaction doesn't necessarily stop at the secondary amine stage. Option B is incorrect as it represents an intermediate, not the complete product mixture. Option C is also incorrect as it is just one of the potential products, not accounting for the others formed during the reaction progression.

Q100. The total energy of a hydrogen atom in its ground state is:

• A. Zero
• B. Negative✓
• C. Positive
• D. None of the above

Explanation: The energy of a hydrogen atom in its ground state is negative, approximately -13.6 eV. This negative value indicates that the electron is bound to the nucleus, requiring energy input to free it. The Schrödinger equation and the Bohr model both support this result, with the ground state corresponding to the principal quantum number n = 1. The other options are incorrect: a zero or positive energy would suggest the electron is not bound to the nucleus, contrary to the nature of a ground state electron.

Q101. Choose reaction that does not require ZnCl3 catalyst:

• A. A) CH3CH2OH + HCl --> CH3CH2Cl + H2O
• B. B) CH3CH2OH + HBr --> CH3CH2Br + H2O
• C. C) CH3CH2OH + HI --> CH3CH2I + H2O
• D. D) Both B & C✓

Explanation: The correct answer is Option D The reaction of ethanol with HBr generally does not require a ZnCl2 catalyst because HBr is a more reactive acid than HCl. In contrast, the reaction with HCl typically needs the catalyst for the reaction to proceed efficiently, as seen in the Lucas test.

Q102. Select the correct reaction of the following:

• A. SnO + 4NaOH --> Sn(OH)4 + 2Na2O
• B. SnO + 4NaOH --> Na4Sn (OH)4
• C. SnO + 2NaOH --> Na2Sn (OH)4
• D. None of the above✓

Explanation: The correct reaction for SnO and NaOH is: SnO + 2NaOH → Na2SnO2 + H2O. In this reaction, tin(II) oxide reacts with sodium hydroxide to produce sodium stannate(II) and water. Option A is incorrect because it suggests an unbalanced reaction with incorrect products. Option B proposes a product that is not chemically feasible. Option C suggests an incorrect product formation that does not occur. Therefore, 'None of the above' is the correct choice as none of the given equations accurately represent the reaction.

Q103. Choose the true statement regarding the reaction given below2Na(g) + Cl2(g)--> 2NaCl(s)

• A. Chloride is oxidized and sodium is reduced
• B. Chlorine acts as an oxidizing agent and sodium as a reducing agent✓
• C. Chlorine acts as a reducing agent
• D. None of the above

Explanation: In the reaction 2Na(s) + Cl2(g) ⟶ 2NaCl(s), sodium (Na) is oxidized to Na+, losing electrons, and thus acts as the reducing agent. Chlorine (Cl₂) is reduced by gaining electrons to form Cl⁻, acting as the oxidizing agent. Therefore, the correct answer is Option B. Options A and C incorrectly describe the roles of chloride and chlorine, and Option D is incorrect because Option B is the accurate description of the reaction.

Q104. What are the values of principal quantum number and azimuthal quantum number for the last electron in Chlorine atom?

• A. 1.6
• B. 1.3
• C. 3.1✓
• D. 6.1

Explanation: The electronic configuration of chlorine is [Ne]3s23p5, indicating that the last electron is in the 3p subshell. The principal quantum number (n) for this electron is 3, corresponding to the third energy level. The azimuthal quantum number (l) is 1 for the p orbital. Options A, B, and D are incorrect because they do not match the quantum numbers for chlorine's last electron.

Q105. Kp = Kc (RT)△n in the equation if △n < 0 then:

• A. Kp = Kc
• B. Kp < Kc✓
• C. Kp > Kc
• D. Kp < 0

Explanation: Kp and Kc are equilibrium constants for reactions involving gases. Kp is used when partial pressures are involved, while Kc is used for molar concentrations. The relationship between them is given by the equation Kp = Kc (RT)△n, where △n is the change in moles of gases. When △n < 0, it implies that the number of moles of gaseous products is less than the number of moles of gaseous reactants, making (RT)△n a fraction. Thus, Kp < Kc. Option B is correct. Option A is valid when △n = 0, making Kp = Kc. Option C occurs when △n > 0, which makes Kp > Kc. Option D is incorrect as equilibrium constants cannot be negative.

Q106. Shown below are portion of orbital diagrams representing the ground state electronic configuration of certain elements. Which of them obeys the Pauli‘s exclusion principle and Hund‘s rules?

• A. Option A
• B. Option B
• C. Option C
• D. Both option B and C are correct✓

Explanation: Options A and D are incorrect because two electrons with the same spin are not added to the same orbitals.

Q107. Chemical shift in NMR spectroscopy is expressed as delta (δ) or tan (t) scale. Choose the correct relationship between δ and t:

• A. δ = 10 – t✓
• B. δ = 10 + t
• C. t = δ – 10
• D. t = 10 – δ

Explanation: In NMR spectroscopy, δ (delta) represents the chemical shift, while t is another scale used to express the same concept. The correct relationship between these two scales is δ = 10 – t. This means that to convert from the t scale to the δ scale, you subtract the tan value from 10. The other options are incorrect because they either add instead of subtract, reverse the roles of δ and t, or suggest a subtraction that doesn't reflect the true relationship.

Q108. Choose the correct statement:DDT an insecticide is considered as:

• A. Very unstable molecule having a half-life of 1⁄2 to 1 year
• B. Unstable molecule having a half-life of 2 to 5 years
• C. Stable molecule having a half-life of 5 to 8 years
• D. Very stable molecule having a half-life of 10 to 15 years✓

Explanation: The correct answer is Option D: 'Very stable molecule having a half-life of 10 to 15 years.' DDT (Dichlorodiphenyltrichloroethane) is a highly stable pesticide with a long environmental half-life, often cited between 2 and 15 years. This persistence is a significant reason for its controversial use and eventual ban in many countries due to environmental and health concerns. The other options underestimate DDT's stability and half-life, making them incorrect.

Q109. Select meta directing group of the following?

• A. –OH
• B. –NR2
• C. –CN✓
• D. –OR

Explanation: The correct answer is –CN. The –CN group is a meta-directing group because it withdraws electron density from the benzene ring, particularly from the ortho and para positions, reducing their reactivity to electrophilic substitution. This makes the meta position relatively more reactive. Other groups like –OH, –NR2, and –OR are electron-donating groups, thus directing substitution to the ortho and para positions.

Q110. The osmotic pressure of dilute solution is given below by relationship:

• A. π = iCRT
• B. π = RCT/M✓
• C. π = nRT/V
• D. π = PV = nRT

Explanation: The correct relationship for the osmotic pressure of a dilute solution is given by the equation π = RCT/M. This equation shows that osmotic pressure is directly proportional to the temperature (T) and molar concentration (C) of the solute, and inversely proportional to the molar mass (M). The formula accounts for the behavior of the solution as it approaches ideal conditions, where R is the ideal gas constant.Option A is incorrect because it includes the van 't Hoff factor, which is not needed for non-electrolyte dilute solutions. Options C and D are incorrect as they refer to the ideal gas law, which is not applicable for calculating osmotic pressure in solutions.

Q111. Choose the one which is not an assumption of collision theory of reaction rate:

• A. For chemical reaction to occur molecule / particles must collide
• B. For reacting molecules / particles must possess a certain minimum amount of energy, the activation of energy
• C. Every collision is not productive✓
• D. For hydrogen molecule formation from atoms require specific orientation

Explanation: Actually, collision theory assumes:Only a fraction of collisions are effective, due to orientation and energy requirements.If interpreted literally as “every collision is unproductive,” it contradicts collision theory, because some collisions are productive.

Q112. A neutron with K.E equal to 0.04ev is called?

• A. Slow neutron✓
• B. Thermal neutron
• C. Fast neutron
• D. Both (a) and (b)

Explanation: Neutrons are categorized based on their kinetic energy. A slow neutron has kinetic energy below about 1 eV, which includes 0.04 eV, thereby classifying it as a slow neutron. Thermal neutrons specifically have an energy of about 0.025 eV, often in thermal equilibrium at room temperature, which does not match 0.04 eV. Fast neutrons, on the other hand, have much higher energies in the range of a few MeV, making them far more energetic than 0.04 eV. Hence, the correct answer is Option A: Slow neutron.

Q113. Radiation damages living organism is primarily due to:

• A. Excitation phenomena
• B. Ionization
• C. Photoelectric effect
• D. Heating
• E. All of them✓

Explanation: The correct answer is All of them.Radiation can harm living organisms through a combination of mechanisms: excitation can cause energy release that damages cellular structures, ionization creates reactive ions that can disrupt DNA and proteins, the photoelectric effect results in electron ejection that compromises molecular integrity, and heating can denature proteins.While each mechanism individually can cause harm, their combined effects often lead to more severe damage. The extent of damage depends on factors like radiation type and dose. Each incorrect option describes a real mechanism of radiation damage, but on their own, they do not encompass the full scope of radiation's impact on biological organisms.

Q114. Pka values of some acids are given below:Choose the weaker acid?

• A. HClO4 (–10)
• B. HBr (–9)
• C. H2SO4 (–3)✓
• D. HCl (–7)

Explanation: The strength of an acid is inversely related to its pKa value: the lower the pKa, the stronger the acid. In this question, we are looking for the acid with the highest pKa value, indicating weaker acidic strength. Among the given options, H2SO4 has a pKa of -3, which is higher than the pKa values of the other acids provided (all of which are more negative). This makes it the weakest acid in this list, although it is still generally considered a strong acid in broader terms. HClO4, HBr, and HCl all have lower pKa values, making them stronger acids.

Q115. The water formed in the combustion analysis is usually absorbed by:

• A. Mg (NO3)2
• B. Mg (ClO4)2✓
• C. Mg (OH)2
• D. Mg (ClO2)2

Explanation: The correct answer is Mg (ClO4)2, or magnesium perchlorate, which is widely used in combustion analysis as a drying agent due to its hygroscopic properties. It effectively absorbs moisture from its surroundings, making it ideal for removing water formed during combustion processes. Other compounds listed, such as magnesium nitrate, magnesium hydroxide, and magnesium chlorite, do not possess the same level of hygroscopic ability and are not typically used for this purpose.

Q116. When small amount of ammonia is added to CUSO4 solution in water, blue PPt of [Cu(H2O)4(OH)2] is formed. The blue PPt dissolves on addition of excess of ammonia. The product formed is:

• A. [Cu(H2O)2 (NH3)2 (OH)2]
• B. [Cu(NH3)4 (OH)2]
• C. [Cu (NH3)4 (H2O)2]2+✓
• D. [Cu (NH3)3 (H2O)3]2+

Explanation: Ammonia acts as a ligand in this reaction, replacing water molecules in the coordination sphere of the copper ion, forming [Cu(NH3)4(H2O)2]2+, a complex ion known as tetraamminediaquacopper (II). The ammonia molecules do not act as hydroxides in this context, hence options B and D are incorrect. Option A is incorrect due to the wrong ligand arrangement. The correct complex is stable and soluble, explaining the dissolution of the blue precipitate.

Q117. Graphite is one of the allotropic form of Carbon it is:

• A. Isotropic
• B. Anisotropic
• C. good conductor of electricity
• D. Both (b) & (c)✓

Explanation: Graphite is one of the allotropic forms of carbon, and it is known to be anisotropic and a good conductor of electricity. Anisotropic refers to a material that exhibits different properties or behaviors in different directions. In the case of graphite, it has a layered crystal structure with strong covalent bonds within each layer, but weak forces between the layers. As a result, graphite has different properties along different crystallographic directions. Graphite's ability to conduct electricity is due to its unique structure. Within each layer of graphite, carbon atoms are arranged in a hexagonal lattice, forming strong covalent bonds. However, between the layers, there are weaker van der Waals forces, which allows for the easy movement of electrons along the layers. This property makes graphite an excellent electrical conductor.

Q118. If one Faraday was to be 30,230 coulombs instead of 96,500 coulombs then charge on an electron is:

• A. 1.5 x 10–19C
• B. 1 x 10–19C
• C. 0.5 x 10–19C✓
• D. 6.02 x 10–19C

Explanation: The correct answer is 0.5 x 10-19C. A Faraday represents the total charge of one mole of electrons. Given that the new value of one Faraday is 30,230 C, you can find the charge of a single electron by dividing 30,230 C by Avogadro's number (6.02 x 1023), which yields 5.0 x 10-20 C, equivalent to 0.5 x 10-19 C. Other options do not correctly apply this division and thus represent incorrect values for the charge of a single electron.

Q119. In the CH3CH2C = CH + H2O ->?

• A. CH3CHO + CH3CHO
• B. CH3CH2CH2CH2 – OH
• C. CH3CH2CH2COOH
• D. CH3CH2COCH3✓

Explanation: The correct answer is D:CH3CH2COCH3. When water is added to an alkyne, it typically undergoes a hydration reaction resulting in the formation of aldehydes or ketones. In this case, the terminal alkyne undergoes hydration to form a ketone. Options A, B, and C suggest products that are not typically formed under these reaction conditions. Option A suggests aldehyde formation from a non-terminal alkyne, which is incorrect. Option B suggests alcohol formation, and option C suggests carboxylic acid formation, both of which are incorrect for this reaction.

Q120. Which statement is correct for three way catalytic converter:

• A. Reduces emission of unburnt HC‘s
• B. Reduces pollutants
• C. Oxidize pollutant like CO
• D. All of the above✓

Explanation: The correct statement is ALL OF THE ABOVE. A three-way catalytic converter is a device that is used to reduce emissions from internal combustion engines. It does this by using a catalyst to speed up chemical reactions that convert harmful pollutants into less harmful substances. The three main pollutants that a three-way catalytic converter reduces are: Nitrogen oxides (NOx): These are formed when nitrogen and oxygen in the air react at high temperatures. NOx can cause respiratory problems and contribute to smog. Carbon monoxide (CO): This is a colorless, odorless gas that is produced when fuel is not burned completely. CO can reduce the amount of oxygen in the blood, which can lead to headaches, dizziness, and even death. Hydrocarbons (HC): These are compounds that contain hydrogen and carbon. HC can contribute to smog and can also be harmful to human health. A three-way catalytic converter uses a combination of platinum, palladium, and rhodium to speed up the reactions that convert these pollutants into less harmful substances. The catalyst works by providing a surface on which the reactions can occur more easily. The three-way catalytic converter is a very effective way to reduce emissions from internal combustion engines. It can reduce NOx emissions by up to 90%, CO emissions by up to 95%, and HC emissions by up to 99%.

Q121. Which of the following are components of homeostatic mechanism;

• A. Receptor, Regulators, Effectors
• B. Receptors, Integrator, Effectors✓
• C. Sensors, Brain, Effectors
• D. All of the above

Explanation: The correct answer is Receptors, Integrator, Effectors. These are the three core components of a homeostatic mechanism:Receptor: Detects external changes and sends this information to the integrator. For example, temperature sensors in the skin detect changes in body temperature.Integrator: Often the brain, it processes the information from receptors and decides on the necessary response. It determines whether the current state deviates from the set point.Effector: Receives instructions from the integrator and acts to bring the system back to its set point. For instance, sweat glands act to cool the body down.Options containing 'Regulators' or 'Brain' are incorrect as they either use non-specific terms or imply a specific organ not universally applicable to all homeostatic processes.

Q122. The electronic transition that is involved in the visible region is:

• A. σ - σ
• B. d – d✓
• C. π - π
• D. π - σ

Explanation: d-d transitions are electronic transitions that occur between the molecular orbitals that are mostly metallic in character; specifically between the d-orbitals of a transition metal complex. When electronic transitions occur between these orbitals, the color observed is complementary to the wavelengths absorbed in the visible region.

Q123. A water sample contains 3.8 x 103g of mercury per kilo gram of the sample. What is the concentration of mercury in parts per million?

• A. 3.8 ppm✓
• B. 38 ppm
• C. 0.38 ppm
• D. 380 ppm

Explanation: The concentration of mercury is calculated by the formula:ppm = (mass of solute / mass of solution) x 106Given that you have 3.8 x 103g of mercury per kilogram of the sample, first convert this to the same units: 3.8 x 103 g/kg is equivalent to 3.8 g/kg. Since 1 kg equals 1,000,000 mg, the concentration is (3.8 / 1000) x 106 = 3.8 ppm.Other options are incorrect due to calculation errors or misinterpretation of the conversion factor to ppm.

Q124. Select the reaction when the supply of air is very limited;

• A. CH4 + 2O2 → CO2 + 2H2O + heat
• B. 2CH4 + 3O2 → 2CO2 + 4H2O + heat
• C. CH3 – CH3 + 7O2 → CO2 + 6H2O + heat
• D. 2CH4 + 2O2 → 2CO + 4H2O + heat✓

Explanation: When oxygen supply is limited, combustion is incomplete, leading to the formation of carbon monoxide (CO) and water (H2O). Option D correctly reflects this situation, as methane reacts with a limited amount of oxygen to produce CO and H2O. The other options (A, B, and C) depict complete combustion scenarios, which occur when there is an ample oxygen supply, resulting in carbon dioxide (CO2) and water.

Q125. The main components of lipstick are:

• A. Mixture of non-volatile oil and solid wax
• B. Mixture of volatile oil and wax
• C. Fats and wax
• D. Fats, oil, and wax✓

Explanation: The correct answer is D: 'Fats, oil, and wax'. Lipsticks typically contain a blend of waxes (like beeswax and carnauba wax) to provide shape and stability, oils (such as castor oil and various vegetable oils) for moisture and ease of application, and fats for texture. Other options are incorrect as they either omit a crucial component or include components not typically used in lipstick formulations.

Q126. Which of the following solution will have

• A. 1 molar solution of urea✓
• B. 1 molar solution of glucose
• C. 1 molar solution of sodium chloride
• D. 1 molar solution of magnesium chloride

Explanation: The correct answer is the 1 molar solution of urea. Urea is a non-electrolyte, meaning it does not dissociate into ions in solution. This makes it contribute to solution properties as a single particle per molecule, unlike electrolytes that increase the number of particles by dissociating into ions.Glucose, similar to urea, is a non-electrolyte and does not dissociate, but the question may be looking for the option that contrasts with electrolytes like NaCl and MgCl2. Sodium chloride dissociates into two ions, and magnesium chloride dissociates into three ions, increasing their effective concentration in terms of particle number, thus affecting colligative properties differently.

Q127. The spin states of a nucleus of an atom in absence of applied magnetic field have:

• A. Different energies
• B. Equal energies✓
• C. Zero energies
• D. High energies

Explanation: In the absence of an applied magnetic field, the spin states of a nucleus of an atom have equal energies. Each spin state corresponds to a possible orientation of the nuclear spin angular momentum, but without the influence of an external magnetic field, these states remain at the same energy level. When an external magnetic field is applied, the energy levels split, a phenomenon known as nuclear Zeeman splitting. This splitting occurs because the magnetic field interacts with the magnetic moment associated with the nuclear spin, resulting in different energy levels.The incorrect options fail to acknowledge that, without an external magnetic field, the energy levels remain equal. Option A suggests different energies, which only occurs when a magnetic field is present. Option C claims zero energies, overlooking the inherent energies due to nuclear spin. Option D suggests high energies, which is inaccurate as the energy levels without a magnetic field are typically low.

Q128. The Sulphur Bacteria which obtain energy by oxidizing H2S instead of water is called:

• A. Alpha proteobacteria
• B. Beta proteobacteria
• C. Gamma proteobacteria✓
• D. Delta proteobacteria

Explanation: The correct answer is Gamma proteobacteria. This group includes chemolithotrophic sulfur bacteria, which are capable of oxidizing H2S to obtain energy. This oxidation process releases energy that the bacteria utilize for growth and reproduction. These bacteria play a crucial role in the environment by participating in the sulfur cycle and have potential applications in biotechnology.In contrast, Alpha proteobacteria and Beta proteobacteria typically use organic compounds for energy, and Delta proteobacteria are more commonly associated with sulfur compound reduction rather than oxidation.

Q129. The ground state energy of H-atom is 13.6 eV. The energy needed to lonize H-atom from its second excited state is:

• A. 1.51 eV✓
• B. 3.4 eV
• C. 13.6 eV
• D. 12.1 eV

Explanation: The energy required to ionize a hydrogen atom from a given state is the difference between the energy of that state and the energy of the ionized state (0 eV). The ground state energy of hydrogen is -13.6 eV. The energy of the second excited state (n=3) is given by the formula E = -13.6/n² eV, which results in an energy of -1.51 eV. Therefore, the energy required to ionize the hydrogen atom from the second excited state is 1.51 eV. Options B, C, and D do not correctly describe the energy required from the second excited state.

Q130. The path traced by beta particles in air is:

• A. Straight
• B. Erratic✓
• C. Circular
• D. Elliptical

Explanation: The path traced by beta particles in air is erratic. This is because beta particles are high-speed electrons emitted during radioactive decay. As they travel, they collide with air molecules, causing them to scatter and lose energy, resulting in a zigzag or erratic path.Option A, Straight, is incorrect because constant collisions with air molecules prevent beta particles from maintaining a straight trajectory over any significant distance.Option C, Circular, and Option D, Elliptical, are incorrect as they describe paths influenced by strong magnetic fields, which beta particles do not experience under normal atmospheric conditions.

Q131. Read the statement carefully and choose the correct option.

• A. 0.693/k✓
• B. 0.693/2k
• C. log2/k
• D. In2/k

Explanation: The half-life of a first-order reaction is given by the formula t1/2 = 0.693/k, where k is the rate constant. This formula comes from integrating the rate law for a first-order reaction. Option A correctly represents this relationship. Option B incorrectly introduces a factor of 2 in the denominator, which is not part of the standard equation. Option C suggests using a logarithmic term that is not the natural logarithm, and option D uses 'In' instead of the correct notation 'ln', which refers to the natural logarithm.

Q132. What is the concentration moles/liter of nitric acid solution having PH of 4?

• A. 0.0001 mol/L✓
• B. -4
• C. 10-4 mol/L
• D. 10-10

Explanation: To determine the concentration of nitric acid in moles per liter with a pH of 4, we apply the formula: pH = -log[H+]. Rearranging gives [H+] = 10-pH. Substituting pH = 4 yields [H+] = 10-4 = 0.0001 mol/L. Since HNO3 dissociates completely in solution, the concentration of HNO3 is equal to the concentration of H+ ions. Thus, the correct concentration is 0.0001 mol/L.Option B (-4) is incorrect because pH cannot be a negative concentration. Option C (10-4) is mathematically correct but usually expressed as 0.0001 mol/L for clarity. Option D (10-10) would relate to a much higher pH value, unsuitable for this question.

Q133. Ethoxy ethane when treated with conc: H2SO4 it produces:

• A. Carbocation
• B. Oxonium ion✓
• C. Carbanion
• D. Oxalate ion

Explanation: When ethoxy ethane is treated with concentrated H2SO4, the oxygen atom in ethoxy ethane donates a lone pair to the hydrogen ion from the acid, forming an oxonium ion. This ion is characterized by the oxygen atom having three bonds and a positive charge.Other options, such as carbocation and carbanion, involve charged carbon species, which are not relevant to this reaction. The oxalate ion is an entirely different anion not involved in the formation of an oxonium ion.

Q134. What is the formula of Dichloro-Bis-ethylenediamine cobalt (II)?

• A. [Co(en)2Cl2]✓
• B. [Co(en)2Cl2]2–
• C. [Co(ebn)2Cl2]1–
• D. [Co(en)2Cl2]1+

Explanation: The correct formula for Dichloro-Bis-ethylenediamine cobalt (II) is [Co(en)2Cl2]. This complex is neutral, with cobalt in the +2 oxidation state, two ethylenediamine ligands acting as bidentate ligands, and two chloride ions. The other options incorrectly suggest charges or use incorrect ligands (e.g., 'ebn' instead of 'en'). Option B and D suggest incorrect charges, while Option C uses an incorrect ligand abbreviation.

Q135. Lithium reacts with air to form:

• A. Li2O
• B. Li2N
• C. Li2O2 + Li2CO3
• D. Both (a) & (b)✓

Explanation: Lithium reacts with the oxygen in the air to form lithium oxide (Li2O) and with nitrogen to form lithium nitride (Li3N). These reactions occur when lithium is heated in the air, and both products are formed as a result of these reactions. Therefore, the correct answer is 'Both (a) & (b)', indicating that both lithium oxide and lithium nitride are produced.Option A and Option B are partially correct because they only consider one aspect of the reaction. Option C is incorrect because Li2O2 and Li2CO3 are not the direct products of lithium reacting with air.

Q136. What will be the shape of a molecule which contains two sigma bond pairs and one lone pair?

• A. Linear
• B. V shape✓
• C. Tetragonal
• D. Triangular

Explanation: The correct molecular shape for a molecule with two sigma bond pairs and one lone pair is V shape or bent. According to VSEPR theory, the presence of a lone pair results in a repulsion that alters the ideal trigonal planar shape into a bent shape, with bond angles less than 120 degrees.Option A is incorrect because linear geometry is typical of molecules with two bonding pairs and no lone pairs, resulting in 180-degree angles.Option C, tetragonal, is incorrect because it involves four bonding pairs, not two.Option D, triangular, is incorrect as it refers to trigonal planar geometry with no lone pairs, which is not applicable here due to the lone pair present.

Q137. Which of the following electronic configuration is/arecorrect?(i) 23Na 1s22s22P63s1(ii)29Cu [Ar] 4s13d10(iii)24Cr [Ar] 4s23d4

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

Explanation: The electron configuration for sodium (23Na) is correctly given as 1s22s22p63s1. Copper (29Cu) also follows the expected pattern of [Ar] 3d10 4s1, which is an exception to the expected filling order due to the stability of a fully filled d sublevel. However, chromium (24Cr) is an exception that does not follow the typical filling order; its electron configuration is [Ar] 3d5 4s1 due to the stability associated with a half-filled d sublevel. Therefore, only statements I and II have correct configurations, making option C the correct choice.

Q138. Which of the following is spontaneous reaction?

• A. Zn + Cu²+ → Zn²+ + Cu✓
• B. Fe + H2O → Fe2+ + OH-
• C. 2H2 + O2 → 2H2O
• D. Ag+ + Cl- → AgCl

Explanation: The correct answer is the reaction Zn + Cu²+ → Zn²+ + Cu. This reaction is spontaneous because it has a positive standard cell potential (E°). The reduction potential of Cu²+ (+0.34V) is greater than that of Zn²+ (-0.76V), indicating that Cu²+ is a stronger oxidizing agent than Zn²+. Therefore, Cu²+ can oxidize Zn, making the reaction spontaneous.The other options are incorrect because they do not meet the criteria for spontaneity under standard conditions. Option B involves Fe and water, which do not react spontaneously. Option C (2H2 + O2 → 2H2O) is not spontaneous without external energy input, and Option D (Ag+ + Cl- → AgCl) does not lead to a positive cell potential under standard conditions.

Q139. Choose atom that is not having a spin quantum number 1/2:

• A. C13
• B. N15
• C. F19
• D. O16✓

Explanation: The correct answer is O16. O16 has an even number of nucleons (8 protons and 8 neutrons), leading to a nuclear spin quantum number of 0. In contrast, C13, N15, and F19 each possess an odd number of nucleons, giving each a nuclear spin quantum number of 1/2.

Q140. Select the correct option.

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

Explanation: The hypothalamus is the region of the forebrain in the floor of the third ventricle, linked with the thalamus above and the pituitary gland below. It contains several important centres controlling body temperature, thirst, hunger, and eating, water balance, and sexual function. It is also closely connected with emotional activity and sleep, and functions as a centre for the integration of hormonal and autonomic nervous activity through its control of the pituitary secretions.

Q141. Excess of BaSO4 was dissolved in pure water at 250C. If its Ksp = 1 x 10–10 what is the Conc: of Ba2+ ions in water?

• A. 10–10
• B. 10–20
• C. 10–5✓
• D. 10–6

Explanation: The solubility product constant (Ksp) for BaSO4 at 25°C is given as 1 x 10–10. The dissolution of BaSO4 in water is represented by the equation:BaSO4 (s) ⇌ Ba2+ (aq) + SO42– (aq)According to the solubility product expression, Ksp = [Ba2+][SO42–]. Assuming the solubility of BaSO4 is x, we have [Ba2+] = x and [SO42–] = x.Therefore, Ksp = x2 = 1 x 10–10. Solving for x gives x = 10–5. This means the concentration of Ba2+ ions in water is 10–5 M, making Option C the correct choice.Options A, B, and D lead to incorrect values for the solubility product, hence they are incorrect.

Q142. The total energy of a particle executing S.H.M. is:

• A. Inversely proportional to the square of the amplitude
• B. Directly proportional to the amplitude
• C. Zero
• D. Directly proportional to the square of the amplitude✓

Explanation: In simple harmonic motion (S.H.M.), the total energy is a constant sum of kinetic and potential energies, and is given by the formula E = (1/2)mω2A2. Here, E is the total energy, m is the mass, ω is the angular frequency of the oscillation, and A is the amplitude.This equation shows that the total energy is directly proportional to the square of the amplitude, which means that if the amplitude is doubled, the total energy increases by a factor of four.Incorrect options: The energy is not inversely proportional to the square of the amplitude (Option A), nor is it directly proportional to the amplitude (Option B). Option C, stating the energy is zero, is incorrect as the energy in S.H.M. is always a positive value, never zero.

Q143. A weight suspended from an ideal spring oscillates up and down with a period T. If the amplitude of the oscillation is doubled, the period will be:

• A. T✓
• B. 1
• C. 2T
• D. T/2

Explanation: The period of a simple harmonic oscillator, such as a weight on an ideal spring, is given by the formula T = 2π√(m/k), where m is the mass and k is the spring constant. The formula shows that the period T is independent of the amplitude of oscillation. Therefore, even if the amplitude is doubled, the period remains the same. Consequently, the correct answer is T. Option B is incorrect as periods are not represented by unitless integers. Option C is incorrect as the period does not double with amplitude. Option D, T/2, is incorrect as the period does not halve.

Q144. A heat engine:

• A. Converts heat input to an equivalent amount of work✓
• B. Converts work to an equivalent amount of heat
• C. Takes heat in, does work, and loses energy as heat
• D. Uses positive work done on the system to transfer heat from a low temperature reservoir to a high temperature reservoir

Explanation: A heat engine is a device that operates on the principle of converting heat energy into mechanical work, often by using a working substance like steam or gas. The engine absorbs heat from a high-temperature reservoir, does work, and expels some heat to a low-temperature reservoir, making it an essential part of many machines, such as steam engines, petrol engines, and diesel engines.Option A is correct because it accurately describes the core function of a heat engine. Option B is incorrect because it describes a heat pump or refrigerator's function, where work is used to move heat against its gradient. Option C, while partially correct, does not highlight the conversion of heat energy to work as the primary purpose. Option D correctly describes a heat pump, not a heat engine.

Q145. If 50 KV is the applied potential in ax X-ray tube then the minimum wavelength of X-rays produced is:

• A. 0.2 nm
• B. 2 nm
• C. 0.02 nm✓
• D. 2 Å

Explanation: To find the minimum wavelength of X-rays produced in an X-ray tube, we use the formula: 𝝺min = hc/qeV, where:h is Planck’s constant (6.626 x 10-34 Js)c is the speed of light (3 x 108 m/s)q is the charge of an electron (1.6 x 10-19 C)V is the applied voltage (50 x 103 V)Plugging in these values, we get:𝝺min = (6.626 x 10-34 Js * 3 x 108 m/s) / (1.6 x 10-19 C * 50 x 103 V) = 0.0248 nm, which rounds to 0.02 nm.The other options are incorrect because they result from incorrect calculations or unit conversions.

Q146. Two projectiles are in flight at the same time. The acceleration of one relative to the other:

• A. Is always 9.8 m/s2
• B. Can be as large as 19.8 m/s2
• C. Can be horizontal
• D. Is zero✓

Explanation: The correct answer is that the acceleration of one projectile relative to the other is zero. This is because both projectiles are subject to the same gravitational force, which provides them with an identical acceleration of 9.8 m/s2 downwards. Therefore, when considering one projectile in relation to the other, there is no difference in acceleration—hence, it is zero.Other options suggest incorrect scenarios: 9.8 m/s2 as a relative acceleration is incorrect because it doesn't account for the fact that both projectiles experience this equally, effectively canceling out any relative difference. 19.8 m/s2 is misleading as it suggests a scenario not possible under uniform gravitational influence. Lastly, horizontal acceleration is not applicable as gravity only affects vertical motion.

Q147. In Compton scattering from stationary electrons the largest change in wavelength occurs when the photon is scattered through:

• A. 00
• B. 450
• C. 900
• D. 1800✓

Explanation: The largest change in wavelength occurs when the photon is scattered through 180 degrees because the photon is reflected directly back in the direction from which it came. At this angle, the photon transfers the maximum amount of energy to the electron, leading to the largest possible increase in its wavelength.In Compton scattering, the change in wavelength is given by the formula: Δλ = (h/mc)(1 - cosθ), where θ is the scattering angle. The term (1 - cosθ) reaches its maximum value at θ = 180°.Option A (0 degrees) results in no change in wavelength because the photon continues in its original path. Option B (45 degrees) and Option C (90 degrees) do result in changes in wavelength, but these changes are not as large as at 180 degrees.

Q148. If the potential difference across a resistor is doubled:

• A. Only the current is doubled✓
• B. Only the current is halved
• C. Only the resistance is doubled
• D. Only the resistance is halved

Explanation: The correct answer is that only the current is doubled. According to Ohm’s law (V = IR), the current through a resistor is directly proportional to the potential difference across it, provided the resistance remains constant. Therefore, if the potential difference is doubled, the current must also be doubled to maintain this relationship. The resistance of the resistor does not change with variations in potential difference or current, as it is an inherent property of the material.

Q149. Nuclear fusion in the sun is increasing in supply of:

• A. Hydrogen
• B. Helium✓
• C. Nucleons
• D. Positrons

Explanation: Nuclear fusion in the sun involves the transformation of hydrogen into helium. This process increases the supply of helium as hydrogen nuclei (protons) are fused to form helium nuclei. Although nucleons are involved in this process, they are not increased in number, just rearranged. Positrons are indeed produced in small amounts during fusion, but they do not represent an increasing supply as helium does.

Q150. The functional group region in infra-red spectrum lies between:

• A. 500 – 1300 cm–1
• B. 600 – 1500 cm–1
• C. 1500 – 4000 cm–1✓
• D. 2500 – 3500 cm–1

Explanation: The functional group region in an infrared spectrum ranges from 1500 to 4000 cm-1. This is where the characteristic absorption peaks of various functional groups, such as -OH, -NH, and C=O, are typically observed. Option A (500 – 1300 cm-1) and Option B (600 – 1500 cm-1) fall within the fingerprint region, which is known for the unique absorption patterns of entire molecules rather than specific functional groups. Option D (2500 – 3500 cm-1) is a subset of the functional group region, but it doesn't cover the entire range where functional groups can be detected, making Option C the most accurate choice.

Q151. In stationary waves:

• A. There is no net transfer of energy✓
• B. Energy is evenly distributed at all points
• C. Phase is the same for all points
• D. Both (a) & (b)

Explanation: In stationary waves, there is no net transfer of energy because the waves are confined, oscillating back and forth within a fixed region. This causes energy to transfer between nodes and antinodes without progressing through the medium. The correct option, therefore, is that there is no net transfer of energy. Option B is incorrect because energy is not evenly distributed; it varies with position. Option C is incorrect because the phase is not uniform; it changes across the wave. Option D is incorrect because it inaccurately suggests both A and B are correct.

Q152. If each vector have unit magnitude than A. A is:

• A. Zero
• B. One✓
• C. Negative One
• D. Two

Explanation: The correct answer is 'One'. When two vectors each have unit magnitude, the dot product is calculated as the cosine of the angle between them. If the vectors are aligned, the angle is 0 degrees, and the cosine of 0 degrees is 1. Thus, the dot product is 1. Options 'Zero', 'Negative One', and 'Two' are incorrect because they do not reflect the properties of the dot product for unit vectors.

Q153. In a purely resistive circuit the current:

• A. Leads the voltage by one-half of a cycle
• B. Leads the voltage by one-fourth of a cycle
• C. Lags the voltage by one-half of a cycle
• D. Is in phase with the voltage✓

Explanation: In a purely resistive circuit, the current and voltage are in phase with each other. This means both reach their maximum and minimum values simultaneously, with no phase shift between them.The reason is that resistance, unlike reactance, does not cause any delay or advancement in the phase of the current relative to the voltage. Therefore, Options A, B, and C are incorrect as they suggest a phase difference, which does not occur in purely resistive circuits. Option D is correct as it accurately describes the in-phase relationship, where the electrical energy is entirely converted into heat without any storage or delay.

Q154. The number of ejected photoelectrons increases with increase.

• A. Increase in intensity of light✓
• B. Increase in wavelength of light
• C. Increase in frequency of light
• D. Never

Explanation: The correct answer is that the number of ejected photoelectrons increases with an increase in the intensity of light. In the photoelectric effect, the intensity of light is proportional to the number of photons hitting a surface per unit time. Therefore, higher intensity means more photons are available to eject more photoelectrons. While frequency and wavelength affect the energy per photon and the ability to eject photoelectrons, they do not directly influence the number of electrons ejected. Thus, increasing the intensity leads to more ejected photoelectrons, assuming the frequency is above the threshold required to overcome the material's work function.

Q155. The number of loops in the standing waves is directly dependent on:

• A. Wavelength
• B. Frequency✓
• C. Velocity
• D. Speed

Explanation: The correct answer is Frequency. The number of loops in a standing wave is directly related to its frequency, as frequency determines how many complete wave cycles fit into a given length. Wavelength does affect the spacing of nodes and antinodes, but the count of loops is a function of frequency. Velocity and speed describe wave propagation characteristics but do not determine the number of loops in the standing wave.

Q156. In Einstein‘s universe what is the fourth dimension:

• A. Distance
• B. Speed
• C. Time✓
• D. Energy

Explanation: Einstein's theory of relativity introduced the revolutionary concept of spacetime, where the three dimensions of space are intertwined with the dimension of time, forming a four-dimensional continuum. This framework allows for the description of events based on four coordinates: three for space and one for time. Time, as the fourth dimension, is integral to understanding how objects move and interact in the universe, particularly under the influence of gravity.The incorrect options can be explained as follows: Distance and speed are related to spatial movement, but they do not represent dimensions in spacetime. Energy, while crucial in Einstein's theories, is not a dimension but rather a quantity that links mass through relativity.

Q157. A.C and D.C have the same:

• A. Effect in charging battery✓
• B. Effect in charging capacitor
• C. Heating effect through a resistance
• D. Effect passing through an inductance

Explanation: The correct option is Effect in charging battery. Both AC and DC can charge a battery, but typically AC is converted to DC for this purpose. The important factor is that the charging mechanism manages the voltage and current appropriately. While AC and DC currents have different characteristics, the end result of charging the battery—restoring its stored energy—can be achieved with both, given the right conditions.Option B is incorrect because capacitors react differently to AC and DC; they charge and discharge continuously with AC. Option C is incorrect because while both AC and DC cause heating, the effect depends on how the AC is measured (RMS value). Option D is incorrect as inductances behave differently under AC, where they induce a current due to the changing magnetic field, unlike the constant field from DC.

Q158. The number of ejected photoelectrons increases with increase. is strong electrolyte?

• A. Ca(OH)2
• B. SiCl4
• C. KCl✓
• D. SrCl2

Explanation: KCl is a strong electrolyte because it fully dissociates into ions (K+ and Cl-) in water, allowing efficient conduction of electricity. Ca(OH)2 is a weak base and weak electrolyte, which means it does not fully dissociate into ions. SiCl4 does not dissociate at all in water, making it a non-electrolyte. SrCl2 was incorrectly described; it is a strong electrolyte as it also fully dissociates in solution.

Q159. X-rays are widely used as a diagnostic tool in medicine because of its:

• A. Particle property
• B. Cost of X-ray unit is low
• C. High penetrating power✓
• D. It is not electromagnetic waves

Explanation: X-rays are a type of electromagnetic radiation with high frequency and energy, which grants them significant penetrating power. This characteristic is essential for medical diagnostics, as it allows X-rays to pass through the body and produce images of bones and other internal structures. This ability to create detailed images is why they are widely used in medicine.Options A and D are incorrect because X-rays are electromagnetic waves, not particles. Option B is misleading as the cost of X-ray machines is not low; their diagnostic utility justifies their expense.

Q160. To obtain greater dispersion by a diffraction grating:

• A. The slit width should be increased
• B. The slit width should be decreased
• C. The slit separation should be increased
• D. The slit separation should be decreased✓

Explanation: The correct answer is to decrease the slit separation. In a diffraction grating, narrower slit separation results in larger angular separation between different diffraction orders. This larger angular separation increases the dispersion, allowing different wavelengths of light to be spread out more effectively. Conversely, increasing the slit separation reduces the angular spread and thus decreases dispersion. Increasing or decreasing the slit width primarily affects the intensity and sharpness of the diffraction pattern, not the dispersion.

Q161. The unit ―henry‖ is equivalent to:

• A. Volt-second/ampere✓
• B. Volt/second
• C. Ohm
• D. Ampere volt/second

Explanation: The unit "henry" (H) is used to measure inductance in the International System of Units (SI). It is defined as the inductance of a circuit in which an electromotive force of one volt is induced when the current through the circuit changes at a rate of one ampere per second. Thus, the unit "henry" is equivalent to "volt-second/ampere." This reflects the relationship between electromotive force, current change rate, and inductance. Other options provided, such as "volt/second," "ohm," and "ampere volt/second," do not accurately describe inductance. "Volt/second" pertains to the rate of change of electric potential, "ohm" is the unit for resistance, and "ampere volt/second" does not correspond to a recognized unit in this context.

Q162. A total charge of 100C flows through a 12W bulb in a time of 50 second. What is the potential difference across the bulb during this time?

• A. 0.12V
• B. 2.0V
• C. 6.0V✓
• D. 24V

Explanation: The correct answer is 6.0V, determined by using the formula P = VI, where P is power, V is voltage, and I is current. Given the power of the bulb is 12W and the current is calculated from the charge and time as 2A (100C / 50s), we find V = 12W / 2A = 6V. This satisfies the power equation perfectly.Option A (0.12V) is incorrect because it implies an unrealistically low power. Option B (2.0V) is incorrect because the resulting power equation doesn't match the conditions. Option D (24V) is incorrect because it suggests a current that would only transfer 25C, not the given 100C.

Q163. Becquerel is the unit of:

• A. Decay constant
• B. Half life
• C. Mean life
• D. Activity✓

Explanation: The Becquerel (Bq) is the standard unit for measuring radioactivity, specifically the activity of a radioactive substance. It quantifies the number of radioactive decays per second, making it a measure of the substance's activity. This is distinct from the decay constant, half-life, and mean life, which relate to probabilities and time intervals rather than direct decay rates.Option A, the decay constant, is a probability measure indicating decay likelihood; Option B, half-life, is a time measure for decay processes; and Option C, mean life, is an average time measure for decay. Only Option D, activity, correctly identifies what is measured by Becquerels, highlighting the rate of decay events per second.

Q164. The changing electric flux in a certain region of space produces:

• A. An electric field
• B. Magnetic field
• C. Both A and B✓
• D. None of the above

Explanation: Faraday's law of electromagnetic induction states that a changing electric flux will result in the induction of a magnetic field. This principle is fundamental in electromagnetism, describing how electric and magnetic fields are interrelated. The correct choice is that both a magnetic and an induced electric field can result from changing fluxes, but not directly from changing electric flux alone. Therefore, the correct answer is that a changing electric flux produces a magnetic field, with the potential to also indirectly influence electric fields through electromagnetic induction processes. Options A and D are incorrect because they don't accurately describe the relationship between electric flux and the fields it influences.

Q165. A laser beam can be sharply focused because it is:

• A. Highly coherent
• B. Plane polarized
• C. Intense
• D. Highly directional✓

Explanation: A laser beam is sharply focused primarily because it is highly directional. This means the light emitted is concentrated along a narrow path, maintaining intensity over distance with minimal spreading due to diffraction. This is in contrast to ordinary light sources, which tend to spread out significantly.While coherence is a defining feature of lasers, making the light waves consistent in phase, it is not the primary reason for the beam's focusability. Plane polarization involves the orientation of light waves and does not affect the beam's focus. Lastly, while intensity refers to the power of the laser, it doesn't influence the beam's directionality or focus.

Q166. A charged capacitor stores 10 C at 40 V.. Its stored energy is:

• A. 400 J
• B. 4 J
• C. 0.2 J
• D. 200 J✓

Explanation: The energy stored in a capacitor can be calculated using the formula U = 0.5 * Q * V, where U is the energy, Q is the charge, and V is the voltage. Given Q = 10 C and V = 40 V, the calculation is U = 0.5 * 10 C * 40 V = 200 J. Therefore, the correct answer is 200 J. The other options (400 J, 4 J, and 0.2 J) are incorrect because they do not follow the correct application of the formula.

Q167. A hydrogen atom that has lost its electron is moving east in a region where the magnetic field is directed from south to north. It will be deflected:

• A. Up✓
• B. Down
• C. North
• D. South

Explanation: The hydrogen atom, which is effectively a proton in this context since it has lost its electron, is moving east in a magnetic field directed from south to north. To find the direction of the magnetic force acting on the proton, we can use the right-hand rule. For a positive charge like a proton, point your right thumb in the direction of the velocity (east), and your fingers in the direction of the magnetic field (north). The direction in which your palm pushes will indicate the direction of the magnetic force, which is upwards in this case. Therefore, the correct answer is up.Option B (down) is incorrect because the right-hand rule does not support this direction. Option C (north) is incorrect as the force does not act along the direction of the magnetic field but rather perpendicular to it. Option D (south) is also incorrect for the same reason; the magnetic force is not directed south based on the right-hand rule.

Q168. The colour of thin films is a result of:

• A. Dispersion
• B. Absorption of light
• C. Scattering of light
• D. Interference of light✓

Explanation: The correct answer is interference of light. The colors seen in thin films result from the interference of light waves reflected from the top and bottom surfaces of the film. Depending on the thickness of the film and the wavelength of the incoming light, certain wavelengths constructively interfere, while others destructively interfere, creating the vivid colors observed. This is different from dispersion, absorption, or scattering, which do not account for the distinct color patterns seen in thin films.

Q169. Read the statement carefully and choose the correct option.

• A. 80Hz✓
• B. 800Hz
• C. 8000Hz
• D. 50Hz

Explanation: The reactance (XL) of an inductor is calculated using the formula XL=2πfL. Given the inductance (L) of 1 henry and the reactance (XL) of 500 ohms, the equation becomes 500Ω=2πf(1H). Solving for the frequency (f), we find f = 500Ω/2π ≈ 79.577Hz. Therefore, the closest choice is 80Hz.Other options like 800Hz, 8000Hz, and 50Hz are incorrect as they do not satisfy the equation with the provided values. Specifically, 800Hz and 8000Hz would lead to higher reactance values, while 50Hz would give a much lower reactance.

Q170. A vector of magnitude 20 is added to a vector of magnitude 25. The magnitude of this sum might be:

• A. Zero
• B. 3
• C. 12
• D. 45✓

Explanation: The magnitude of the sum of two vectors can be determined using the triangle law of vector addition. This law states that if two vectors are represented as sides of a triangle, then the sum of the two vectors can be represented by the third side of the triangle.In this case, if a vector of magnitude 20 is added to a vector of magnitude 25, the magnitude of the sum could be anywhere between ∣20−25∣=5 (if the two vectors are in opposite directions) and 20+25=45 (if the two vectors are in the same direction).Out of the given options, the closest one to the potential range of magnitudes is: 45However, it's important to note that the exact magnitude of the sum will depend on the relative directions of the two vectors. The magnitude will be smaller if they are opposing and larger if they are aligned.

Q171. The time period of a simple pendulum is 2 seconds. If its length is increased by 4 times, then its period becomes:

• A. 16 sec
• B. 12 sec
• C. 8 sec
• D. 4 sec✓

Explanation: The formula for the period of a simple pendulum is T = 2π √(l/g). The period is directly proportional to the square root of the length. Therefore, if the length is increased by 4 times, the period becomes √4 times the original period, which is 2 times. Hence, the original period of 2 seconds becomes 4 seconds. The other options are incorrect because they miscalculate the effect of the increased length on the period.

Q172. A moving charged particle is surrounded by?

• A. 1 field
• B. 3 fields✓
• C. 2 fields
• D. 4 fields

Explanation: A moving charged particle is surrounded by three fields:Electric Field: This field arises due to the charge of the particle itself and affects other charges in its vicinity.Magnetic Field: Generated due to the movement of the charge. The interaction between charge and motion creates this field.Gravitational Field: The mass of the particle generates a gravitational field, albeit usually very weak compared to the other two fields.Option A (1 field) is incorrect because it ignores the presence of the magnetic and gravitational fields. Option C (2 fields) is incorrect as it overlooks the gravitational field. Option D (4 fields) is incorrect because there isn't an additional field present beyond the electric, magnetic, and gravitational fields mentioned.

Q173. Water flows from a 6.0cm diameter pipe into 8.0cm diameter pipe. The speed in the 6.0cm pipe is 5.0m/s. the speed in the 8cm pipe is:

• A. 2.8m/s✓
• B. 3.7m/s
• C. 6.6m/s
• D. 8.8m/s

Explanation: The problem can be solved using the continuity equation, which states that A1V1 = A2V2, where A is the cross-sectional area of the pipe. For circular pipes, A = πr2, so:For the 6.0 cm diameter pipe, r1 = 3 cm, and for the 8.0 cm diameter pipe, r2 = 4 cm.Substituting these into the equation:π(3)2 × 5.0 = π(4)2 × V245 = 16V2V2 = 45/16 = 2.8 m/sThe correct answer is 2.8 m/s. The other options are incorrect as they do not satisfy this calculation based on the continuity equation.

Q174. The infrared spectra commonly referred to as IR spectra is usually expressed as:

• A. Wavelength
• B. Wavenumber
• C. Frequency
• D. All of the above✓

Explanation: The correct answer is All of the above. Infrared spectra can be expressed in terms of wavelength, wavenumber, or frequency, each offering distinct advantages in different contexts:Wavelength: Useful for comparing spectra from different sources or under varying conditions.Wavenumber: Ideal for calculations related to molecular vibrations, providing a unit independent of sample physical properties.Frequency: Relevant for speed-related calculations of IR radiation.While each unit is valid, the context and specific requirements of the analysis determine the most appropriate choice. Hence, IR spectra are commonly expressed using any of these units.

Q175. A particle, held by a string whose other end is attached to a fixed point C, moves in a circle on a horizontal frictionless surface. If the string is cut, the angular momentum of the particle about the point: C.

• A. Increases
• B. Decreases
• C. Remains constant✓
• D. Changes direction but not magnitude

Explanation: Angular momentum is a conserved quantity in the absence of external torques. When the string is cut, the particle continues to move tangentially to its circular path. Since there is no external force or torque acting on the particle with respect to the fixed point C, the angular momentum remains constant.Option A is incorrect because without external torque, angular momentum cannot increase. Option B is incorrect for the same reason—it cannot decrease. Option C is correct because it reflects the principle of conservation of angular momentum. Option D is incorrect because while the particle's trajectory changes, the concept of angular momentum about a point doesn't involve changes in direction without external torque.

Q176. An electron has charge (e) and mass (m). A proton has charge e and mass 1840m. A "Proton volt" is equal to:

• A. A✓
• B. B
• C. C
• D. D

Explanation: The problem defines a "Proton volt" as the energy gained by a proton (charge qp​=+e) when it moves through an electric potential difference of 1 volt (ΔV=1 V).1 Proton volt=(charge of proton)×(1 V)=1eV.

Q177. The rotational inertia of a disk about its axis is 0.70 Kg. m2. When a 2.0-kg weight is added to its rim, 0.40m from the axis, the rotational inertia becomes:

• A. 0.38 kg – m2
• B. 0.54 kg – m2
• C. 0.86 kg – m2
• D. 1.02 kg – m2✓

Explanation: The correct answer is 1.02 kg – m2. The initial rotational inertia of the disk is 0.70 kg m2. When a 2.0 kg mass is added at a radius of 0.40 m, the additional moment of inertia is calculated using Im = m × r2. Substituting the values gives Im = 2.0 kg × (0.40 m)2 = 0.32 kg m2. Adding this to the original inertia results in a total of 1.02 kg m2. The other options underestimate the impact of the added mass, leading to incorrect calculations of the total rotational inertia.

Q178. Which of the following is closest to a yard:

• A. 0.01 m
• B. 0.1 m
• C. 1 m✓
• D. 100 m

Explanation: The correct answer is 1 meter because a yard is approximately 0.9144 meters, making 1 meter the closest option. A yard is a unit of length used in the imperial system, and when converted to the metric system, it measures just under one meter. The other options are either too small (0.01 m and 0.1 m) or too large (100 m) to be considered close to a yard.

Q179. You stand on a spring scale on the floor of an elevator. Of the following, the scale shows the highest reading when the elevator:

• A. Moves upward with increasing speed✓
• B. Moves upward with decreasing speed
• C. Remains stationary
• D. Moves downward with increasing speed

Explanation: The correct answer is that the scale shows the highest reading when the elevator moves upward with increasing speed. This is because the elevator's upward acceleration adds to the gravitational force, increasing the normal force exerted on the scale. In physics terms, the apparent weight is the sum of the gravitational force (mg) and the force due to acceleration (ma), resulting in a higher reading on the scale.In contrast, moving upward with decreasing speed indicates downward acceleration, reducing the normal force. Remaining stationary results in no additional forces beyond gravity, reflecting your true weight. Moving downward with increasing speed causes downward acceleration, further decreasing the normal force and the scale reading.

Q180. A wheel starts from rest and has an angular acceleration of 4.0 rad/s2. When it has made 10 rev its angular velocity is:

• A. 16 rad/s
• B. 22 rad/s✓
• C. 32 rad/s
• D. 250 rad/s

Explanation: To find the final angular velocity ωf, use the rotational kinematics equation: ωf = ωi + 2aθ. Given that the initial angular velocity ωi is 0 rad/s (since the wheel starts from rest), a is 4 rad/s2, and the angular displacement θ is 62.83 rad (10 revolutions), we calculate:ωf = 0 + √(2 * 4 * 62.83) = 22.41 rad/s.Thus, the correct answer is 22 rad/s.Options A, C, and D are incorrect because they result from incorrect applications of the formula or assumptions, leading to miscalculations.

Q181. Signal from a remote control to the device operated by it, travels with the speed of:

• A. Sound
• B. Supersonic
• C. Ultrasonic
• D. Light✓

Explanation: The correct answer is that the signal from a remote control travels at the speed of light. This is because remote controls typically use infrared radiation, which is a form of light. Infrared radiation is part of the electromagnetic spectrum and travels at the same speed as light, approximately 299,792 kilometers per second in a vacuum.Sound and ultrasonic waves travel much slower than light, at about 340 meters per second in air. Supersonic refers to speeds faster than sound but not approaching the speed of light. Hence, these options are incorrect for describing how remote control signals travel.

Q182. Which of the following electromagnetic waves has the smallest wavelength?

• A. X-rays
• B. Gamma rays✓
• C. Microwaves
• D. Ultraviolet rays

Explanation: Gamma rays have the smallest wavelength of all electromagnetic waves, making them the highest in energy. They are positioned at the extreme end of the electromagnetic spectrum. X-rays, while also having short wavelengths, are longer than gamma rays. Microwaves and ultraviolet rays have significantly longer wavelengths compared to gamma rays, with microwaves being one of the longest in the spectrum.

Q183. The temperature coefficient of resistance of a semiconductor is:

• A. Positive
• B. Negative✓
• C. Imaginary
• D. Zero

Explanation: The temperature coefficient of resistance for a semiconductor is negative, indicating that its resistance decreases as temperature increases. This is because higher temperatures provide energy to electrons, pushing them into the conduction band and increasing the number of charge carriers, thus reducing resistance. In contrast, metals have a positive coefficient because increased atomic vibration at higher temperatures hinders electron flow, increasing resistance. Insulators, with negligible charge carriers, show little change in resistance with temperature, and thus might be considered to have a zero coefficient. The concept of an imaginary coefficient is not applicable in this context.

Q184. Angle that a body traverses at the centre of a circle in two turns is:

• A. 180 degrees
• B. 360 degrees
• C. 540 degrees
• D. 720 degrees✓

Explanation: A full turn around a circle is 360 degrees or 2π radians. For two complete turns, multiply the angle of one turn by 2, resulting in 720 degrees or 4π radians. The correct answer is 720 degrees.Option A (180 degrees) is incorrect because it represents only a half turn. Option B (360 degrees) is incorrect because it represents only one turn. Option C (540 degrees) is incorrect because it represents one and a half turns.

Q185. Two tuning forks of frequencies 256Hz and 260Hz are sounded together the time interval between two consecutive maximum sound heard by a listener is:

• A. 0.5 Sec
• B. 2 Sec
• C. 1 Sec
• D. 0.25 Sec✓

Explanation: The beat frequency is determined by the difference between the two frequencies: Δf = 260 Hz - 256 Hz = 4 Hz. The time interval between consecutive maximum sounds, or beats, is the reciprocal of the beat frequency. Thus, T = 1/Δf = 1/4 s-1 = 0.25 seconds. Options A, B, and C are incorrect as they do not match the calculation based on the beat frequency.

Q186. Intrinsic semi-conductor can be converted into extrinsic semi-conductor by adding:

• A. Trivalent impurity
• B. Pentavalent impurity
• C. Pentavalent or trivalent impurities✓
• D. None of the above

Explanation: Intrinsic semiconductors, like silicon (Si) and germanium (Ge), have equal numbers of electrons and holes. By adding a small amount of impurity, known as doping, the semiconductor's electrical properties can be modified, turning it into an extrinsic semiconductor. Trivalent impurities, such as boron (B), create a p-type semiconductor by introducing holes, while pentavalent impurities, such as phosphorus (P), create an n-type semiconductor by providing additional electrons. Therefore, both types of impurities can convert intrinsic semiconductors to extrinsic ones, which is why Option C is correct. Option A and Option B are partially correct but do not encompass the full solution, and Option D is incorrect as both impurity types are valid.

Q187. A 30-cm long string, with one end clamped and the other free to move transversely, is vibrating in its second harmonic. The wavelength of the constituent traveling waves is:

• A. 10 cm
• B. 30 cm
• C. 40 cm✓
• D. 120 cm

Explanation: The correct answer is 40 cm. For a string fixed at one end and free at the other, the second harmonic corresponds to one full wavelength fitting within the length of the string. Since the string is 30 cm long, the wavelength of the constituent traveling waves is 60 cm, which matches Option C. Other options either understate or overstate the wavelength based on incorrect assumptions about the harmonic pattern.

Q188. An object of mass 1 g is whirled in a horizontal circle of radius 0.5m at a constant speed of 2m/s. The work done on the object during one revolution is:

• A. 0 J✓
• B. 1 J
• C. 2 J
• D. 4 J

Explanation: The work done on an object is calculated by the product of the force component in the direction of motion and the displacement. In circular motion at constant speed, the centripetal force is always perpendicular to the displacement, resulting in zero work done. This is because work is only done by forces that have a component in the direction of displacement, which is not the case here.Option A is correct because it recognizes that the perpendicular nature of centripetal force results in zero work done. Options B, C, and D incorrectly suggest that non-zero work is done, misunderstanding the role of force direction in work calculation.

Q189. A mass accelerates uniformly when the resultant force acting on it is:

• A. Zero
• B. Constant but not zero✓
• C. Increases uniformly with respect to time
• D. Both (a) & (c)

Explanation: A mass accelerates uniformly when the resultant force acting on it is constant but not zero. This is because a constant, non-zero force ensures a steady, unchanging acceleration as per Newton's second law (F = ma). If the force is zero, the mass either remains in its current state of motion or at rest, indicating no acceleration. If the force increases uniformly, the acceleration will also increase, resulting in non-uniform acceleration. Option D is incorrect as it combines two mutually exclusive scenarios.

Q190. In Young‘s double slit experiment both the separation between the slits and the distance between the slits and the screen are halved; then the fringe width is:

• A. Halved
• B. Unchanged✓
• C. Doubled
• D. Zero

Explanation: In Young's double-slit experiment, the fringe width is calculated using the formula:wavelength * distance_to_screen / distance_between_slitsIf both the distance between the slits and the screen and the separation between slits are halved, they cancel each other's effect in the formula. Therefore, the fringe width remains unchanged.Option A (Halved) is incorrect because the changes cancel each other out. Option C (Doubled) is incorrect for the same reason. Option D (Zero) is incorrect because halving distances does not make the fringe width zero. Therefore, the correct answer is Option B: Unchanged.

Q191. In pure inductance, the average power dissipated is:

• A. 1
• B. Greater than 1
• C. Less than 1 but greater than zero
• D. Zero✓

Explanation: In a purely inductive circuit, the average power dissipated is zero. This is because the current and voltage are 90 degrees out of phase, resulting in a zero product when calculating average power over a complete cycle. The energy stored in the magnetic field is returned to the circuit, so no net power is dissipated.Option A, B, and C are incorrect because they suggest that power is dissipated, which contradicts the nature of pure inductance where energy is conserved and cycled back into the system.

Q192. As a loop of wire with a resistance of 10Ω moves in a constant non-uniform magnetic field, it loses kinetic energy at a uniform rate of 4.0 ms/s. The induced current in the loop is:

• A. 0 mA
• B. 2 mA
• C. 2.8 mA✓
• D. 20 mA

Explanation: The induced current in the loop is 2.8 mA. The rate of loss of kinetic energy is equal to the power dissipated in the loop, which is given by the formula: P = I2R, where P is the power dissipated, I is the induced current, and R is the resistance of the loop.Given that the rate of power dissipation (P) is 4.0 mW and the resistance (R) is 10 Ω, we calculate the current as:I = sqrt(P/R) = sqrt(4.0/10) = 2.8 mA.Therefore, option C is correct. Options A, B, and D are incorrect as they do not correctly apply the formula to find the induced current.

Q193. Two objects, P and Q have the same momentum. Q has more kinetic energy than P if it:

• A. Weighs more than P
• B. Is moving faster than P✓
• C. Weighs the same as P
• D. Is moving slower than P

Explanation: To determine which object has more kinetic energy when two objects have the same momentum, examine their speeds. Momentum (p = mv) being equal means that a heavier object (Q) must be moving slower than a lighter object (P) to maintain the same momentum. However, kinetic energy (KE = (1/2)mv2) is more affected by speed than mass because velocity is squared in the formula. Therefore, if Q is moving faster, it will have more kinetic energy despite potentially having less mass. This makes option B correct. Options A and D are incorrect because they imply Q is moving slower, which would result in less kinetic energy. Option C is incorrect because the same mass and momentum imply the same speed and kinetic energy.

Q194. A child riding on a large merry-go-round travels a distance of 3000m in a circle of diameter of 40m. The total angle through which she revolves is:

• A. 50 rad
• B. 75 rad
• C. 150 rad✓
• D. 314 rad

Explanation: The following is the solution:The diameter of the merry-go-round is 40mr=40/2=20mCircumference of the merry-go-round is 2πr=2×22/7×20=880/7=125.71 mThe distance he covered was 3000m so, 3000/125.71=23.86 or 24 approx hence he covered 24 times the merry-go-round for 1 cover=360° for 24 times=360×24=8640° =150rad.

Q195. The value of work done by the spring force may be:

• A. All of these✓
• B. Zero
• C. Positive
• D. Negative

Explanation: The work done by the spring force can be positive, negative, or zero depending on the direction of motion and position of the particle. When the particle moves towards the mean position from an extreme position, the work done is positive because the force and displacement are in the same direction. Conversely, when moving from the mean position to an extreme position, the work done is negative as the force opposes the motion. However, over a complete cycle, the net displacement is zero, and thus the net work done is zero. Therefore, all options are possible, making 'All of these' the correct answer.

Q196. In water pipes _ is used to detect leakages.

• A. Radiation✓
• B. Light
• C. Current
• D. None of these options are correct

Explanation: Radiation is used to detect leakages in water pipes due to its ability to penetrate materials and reveal hidden defects. Specifically, radioactive tracers can be introduced into the water system, and their movement can be tracked with specialized detectors to identify leak locations. This method provides accurate results in pinpointing leaks.Other options such as light and current are ineffective for this purpose. Light cannot reveal leaks in opaque materials like pipes, and current doesn't change significantly with the presence of leaks, making these methods unsuitable for leak detection.

Q197. Stationary waves are result of _ travelling in opposite direction waves.

• A. Identical✓
• B. Different
• C. Any of Option A or B
• D. Stationary waves cannot be formed

Explanation: Stationary waves, or standing waves, are formed when two waves of the same amplitude and frequency travel in opposite directions along the same medium and interfere with each other. This interference results in a pattern of nodes (points of no motion) and antinodes (points of maximum motion), creating a wave pattern that appears to be standing still. This phenomenon is crucial in musical instruments, where the vibration of strings or air columns produces sound.Option A is correct because it accurately describes the condition for forming stationary waves: two identical waves traveling in opposite directions. Option B is incorrect because different waves cannot produce the consistent interference pattern needed for stationary waves. Option C is incorrect because it implies that both identical and different waves can form stationary waves, which is not true. Option D is incorrect because it falsely claims that stationary waves cannot be formed.

Q198. When the source is at the center of the circle and the observer is moving on the circumference of the circle, sound heard by the observer is:

• A. Increasing
• B. Decreasing
• C. Same✓
• D. Different

Explanation: The radius(distance between observer and source) of the circle is the same at every point of the circumference. Hence, the observer moving along the circumference of the circle will experience no change in frequency since there is no change in the distance.

Q199. 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 provides a mathematical description of force as it relates to mass and acceleration, forming the basis for understanding interactions between objects. From these interactions, Newton's third law can be derived, stating that for every action, there is an equal and opposite reaction. Newton's first law does not offer this mathematical basis, as it focuses solely on the state of motion without external forces. The option suggesting they are unrelated is incorrect, as Newton's laws collectively describe motion and force interactions. Thus, the correct answer is option B.

Q200. Molecular theory for metals is also called as:

• A. Electron pool theory
• B. Valence bond theory
• C. Band Theory✓
• D. None of these options are correct

Explanation: The molecular theory for metals is called band theory. Band theory is a quantum mechanical model that explains the behavior of electrons in solids by grouping them into energy bands. In metals, the delocalization of valence electrons allows them to move freely, offering an explanation for various metallic properties such as electrical conductivity, reflectivity, and melting points.Other options, like electron pool theory and valence bond theory, fail to encompass the full range of metallic properties. Electron pool theory is more simplistic and less comprehensive, while valence bond theory is tailored to covalent bonding in molecules rather than metals.