Etea Mdcat 2011 — Solved Past Paper with Answers

Q1. We need _ guidelines to start with.

• A. a few✓
• B. any
• C. little
• D. some

Explanation: In this sentence, 'a few' is the correct choice as it indicates a known number of guidelines to start with. 'Any' implies an indefinite number, 'little' conveys a small quantity which is not suitable, and 'some' suggests an unspecified amount. Therefore, 'a few' is the most appropriate option in this context.

Q2. The authorities have _ that the plane to Beirut was hijacked over the Indian Ocean.

• A. Assured
• B. Confirmed✓
• C. Committed
• D. Ensured

Explanation: Confirmed means when the truth or validity of something is attested to. In the context of this sentence, 'confirmed' makes the most sense. Assured means characterized by certainty or security; to be guaranteed Committed means dedicated to something. Ensured means to make sure of something.

Q3. She has let _ her house fully furnished to a Korean couple.

• A. out✓
• B. at
• C. up
• D. in

Explanation: The phrasal verb 'let out' means to allow someone to use a room, building, etc. in exchange for money. It is the most suitable option for this sentence. Let at is not a phrasal verb. Let up means to relax one's efforts. Let in means to allow something to enter.

Q4. Your _ too long you had better go to the hairdresser today:

• A. Hair is✓
• B. Hair are
• C. Hairs are
• D. Hairs is

Explanation: Hair is an uncountable noun so it will be used in the singular form. The verb used with hair will also be singular so the correct option is 'hair is'.

Q5. I have no _ to listen to the budget speech.

• A. Trouble
• B. Convenience
• C. Patience✓
• D. Perseverance

Explanation: Patience is the ability to wait, or to continue doing something despite difficulties, or to suffer without complaining or becoming annoyed.Trouble means difficulty or problems.Convenience is the state of being able to proceed with something without difficulty.Perseverance is persistence in doing something despite difficulty.Out of the given options, patience is the most suitable word here.

Q6. You can always count on me. I will not let you _.

• A. Alone
• B. Down✓
• C. Off
• D. Through

Explanation: The phrase 'let you down' means to disappoint or fail to support someone, making Option B the correct choice. 'Alone' suggests solitude, which is unrelated to the context. 'Off' could imply separation or a different action, and 'through' implies seeing something to completion, neither of which fit the sentence.

Q7. Styles _ popular in the 1950s are reappearing in high fashion boutiques.

• A. what have been
• B. which have been
• C. that have been
• D. that were✓

Explanation: The correct answer is 'that were' because it accurately uses the past tense to describe styles that were popular in the 1950s. The relative pronoun 'that' is used correctly to introduce a defining clause describing the styles. The other options either use incorrect relative pronouns or verb tenses that do not align with the historical timeframe indicated in the sentence.

Q8. Waeem _ him MD for many years, but he is rather unhappy with his salary.

• A. is working in
• B. is serving
• C. is working for
• D. has been working✓

Explanation: The correct answer is 'has been working' because it uses the present perfect continuous tense, which is appropriate for actions that started in the past and continue into the present, especially when expressing dissatisfaction with a current situation. The other options do not convey this ongoing duration.

Q9. Tahira as well as her brother _ responsible for the loss and they must be made to make up for it:

• A. is✓
• B. are
• C. were
• D. have been

Explanation: The correct answer is Option A: 'is'. When a sentence uses 'as well as', the verb should agree with the first subject. Here, 'Tahira' is the first subject and it is singular, so the correct verb is 'is'. 'Are' would be correct if the subject were plural, 'were' is the past tense which does not fit the present context, and 'have been' is incorrect for a singular subject.

Q10. She _ her parents. They must be worried about her health.

• A. Had better call✓
• B. Had better called
• C. Had better to call
• D. Better call

Explanation: The correct answer is Option A: 'She had better call her parents.' The phrase 'had better' is used to give advice or suggest that something should be done. It is always followed by the base form of the verb. Option B is incorrect because it uses the past tense 'called,' which is not used after 'had better.' Option C is incorrect because 'had better' should not be followed by 'to.' Option D is incorrect because 'better' alone does not convey the advice meaning without 'had.'

Q11. He _ before the interview board.

• A. was afraid to appear
• B. was afraid of appearing✓
• C. was afraid of appearance
• D. feared appearance

Explanation: was afraid of appearing: This is the correct choice. It indicates a fear of the action of appearing before the interview board, which fits well in this context.

Q12. He said, "If I were you, I would protest." This can be indirectly reported as:

• A. If he had been me, he would have protested✓
• B. He advised us to protest
• C. If he were me, he would protest
• D. If he had been I, he would have protested

Explanation: In converting direct speech to reported speech, pronouns and verb tenses must be adjusted. The original statement, 'If I were you, I would protest,' when reported indirectly becomes, 'He said that if he had been me, he would have protested.' This involves changing 'I' to 'he,' and 'were' to 'had been,' as well as 'would protest' to 'would have protested,' to reflect the hypothetical condition in the past. Option A is correct. Options B, C, and D either change the meaning or do not correctly apply the rules of indirect speech.

Q13. _ in the world.

• A. our's is not one of the quickest response system
• B. our is not one of the quickest response system
• C. ours is not one of the quickest response system✓
• D. our is not one of the quickest response system

Explanation: The correct answer is Option C: 'ours is not one of the quickest response system.' The word 'ours' is a possessive pronoun that correctly indicates ownership or relation without needing an additional noun. 'Our's' is not a correct form, as possessive pronouns do not include an apostrophe. 'Our' requires a noun to follow (e.g., 'our system') in order to be grammatically correct, which is why Options A, B, and D are incorrect.

Q14. A good businessman should not be unscrupulous while making profits The underlined word means:

• A. unprincipled✓
• B. careless
• C. illegal
• D. miserly

Explanation: The word unscrupulous refers to a lack of moral principles or being unethical, as highlighted in Option A, which is unprincipled. The other options are incorrect because: 'careless' refers to negligence rather than ethics; 'illegal' relates to breaking laws, not necessarily lacking principles; and 'miserly' describes someone who is stingy, not someone who is unprincipled.

Q15. "Cynic' and _ are synonyms:

• A. Skeptic✓
• B. Secret
• C. Solitary
• D. Truthful

Explanation: The word 'cynic' refers to a person who doubts or questions the sincerity or motives of others, often believing that humans are motivated by self-interest. The correct synonym is 'skeptic', which also denotes a person who questions or doubts accepted opinions. The other options do not align with this meaning: 'secret' is unrelated to questioning or doubting, 'solitary' pertains to being alone, and 'truthful' relates to honesty rather than skepticism.

Q16. 'Professional' and '_' are antonyms.

• A. Unemployed
• B. Entrepreneur
• C. Amateur✓
• D. Capitalist

Explanation: The opposite of a professional person is someone who is incompetent and engages in an activity on an unpaid basis. This fits the definition of 'amateur', therefore option 'C' is the right answer.

Q17. Secrets leak when the _ are many.

• A. Enemies
• B. Ill-wishers
• C. Confidants✓
• D. Detractor

Explanation: A confidant is a person whom one can entrust his/her secrets to. Having many confidants means that the secrets are beheld by many people and consequently, there is a greater chance of betrayal and disclosure of secrets. Thus, this is the correct answer.

Q18. The guard looked at me _ and then asked me to identify myself.

• A. Dangerously
• B. Hurriedly
• C. Suspiciously✓
• D. Nervously

Explanation: The correct answer is 'suspiciously' because a security guard's role involves being observant and cautious about potential threats or unusual behavior. When a guard asks someone to identify themselves, it is often due to a suspicion that needs to be verified, making 'suspiciously' the most appropriate choice. The other options do not fit the context: 'dangerously' suggests a threat, 'hurriedly' implies urgency, and 'nervously' suggests anxiety, none of which are typical of a guard's professional behavior in this scenario.

Q19. She tried to _ my question, but i persisted in having an answer.

• A. Refrain
• B. Evade✓
• C. refuse
• D. deny

Explanation: Evade means to escape or avoid something. So option B is correct.

Q20. Her _ lasted for one month. They were the longest wedding celebrations in that area.

• A. rituals
• B. matrimonial
• C. nuptials✓
• D. rites

Explanation: Here, ‘nuptials’ fits the best. Option ‘B’ could also be considered, but only if it was a matrimonial marriage instead of only matrimonial, because it makes no sense.

Q21. Which of the following diseases is NOT caused by bacteria?

• A. tetanus
• B. small pox✓
• C. tuberculosis
• D. diptheria

Explanation: Smallpox is caused by a virus, the variola virus, not a bacterium. Tetanus is caused by a bacterium called Clostridium tetani. Tuberculosis is caused by a bacterium called Mycobacterium tuberculosis. Diphtheria is caused by strains of bacteria called Corynebacterium diphtheriae.

Q22. Round worms, which have body cavities that are partially lined with mesoderm, are classified as:

• A. Acaelomate
• B. ceolomates
• C. Pseudocoelomates✓
• D. Deuterostomes

Explanation: A pseudocoelomate is an organism with a body cavity called a pseudocoelem that is not derived from the mesoderm, as in a true coelom, or body cavity. In invertebrates, the pseudocoelom is filled with fluid that lies between the mesoderm layer of the external body wall and the endoderm layer of the gut. But this is not a true coelem as it originates from the blastocoel, not the archenteron of Gastrula, which is the true site of origin of coelem. Roundworms in the phylum Aschelminthes are pseudocoelemates.

Q23. The hypothesis of Ronald Ross relating to malaria was:

• A. Plasmodia are the cause of malaria.
• B. Bad air is involved in the spread of malaria.
• C. Mosquitoes are possible carriers of Plasmodium.✓
• D. Malaria is caused by bad air coming from marshy places.

Explanation: Ronald Ross's hypothesis and subsequent research demonstrated that mosquitoes, particularly the Anopheles species, are vectors for the Plasmodium parasite, which leads to malaria. This was a groundbreaking discovery because it identified the mosquito as the carrier rather than attributing the disease to environmental factors like bad air, as suggested by the miasma theory. The other options incorrectly focus on outdated or already known aspects of malaria transmission, rather than Ross's specific contribution.

Q24. Crustaceans are the only arthropods that have:

• A. chitin in their exoskeleton
• B. chlicitae
• C. three pairs of legs
• D. two pairs of antennae✓

Explanation: Crustaceans are the only arthropods with two pairs of antennae, so option D is correct. All arthropods have chitin in their exoskeleton. Chelicerae are mouth parts present in some arthropods like arachnids, horseshoe crabs, and sea spiders, but they are absent in crustaceans. Crustaceans have five pairs of legs, not three.

Q25. A cloned baby sheep "Dolly" was attributed to

• A. Four Parents
• B. Three Parents
• C. Two parents
• D. One Parent only✓

Explanation: Cloning is a mode of asexual reproduction through which genetically identical copies of an organism are produced. 'Dolly' the sheep was cloned from one adult somatic cell and is therefore attributed to one parent only.

Q26. In spiders, the organs that contain the silk glands are called

• A. spinneret✓
• B. Carapace
• C. Medriporite
• D. Tube feet

Explanation: Spiders, which belong to the phylum Arthropoda, are predators who trap their prey by producing silk threads. The spinneret is the silk-producing organ in spiders.

Q27. Which of the following bird structures are especially adapted to support flight?

• A. Cloacas
• B. Bills
• C. Gizzard
• D. chest muscles✓

Explanation: The shape of the sternum and chest muscles aid birds in flight.

Q28. Which of the following is composed of lipids?

• A. Some hormones✓
• B. Enzymes
• C. Skin terdons
• D. insulin

Explanation: Steroid hormones are derived from lipids. They include testosterone, estrogen, and cortisol, among others.

Q29. The rate of breathing of a child of 5 years is about:

• A. 44 times/minute
• B. 40 times/minute
• C. 25 times/minute✓
• D. 20 times/minute

Explanation: The breathing rate decreases with age. Some average breathing rates are given below: 2-5 years= 25–30 breaths/min 5-12 years= 20 to 25 breaths /min >12 years= 15 to 20 breaths/min Option C is most suitable here, as 25 breaths/min falls between the first two age groups given.

Q30. The middle lamella of the cell wall is composed of:

• A. Cellulose
• B. pectin✓
• C. Lignin
• D. Murein

Explanation: The middle lamella is made up of pectin in the form of calcium and magnesium pectates. It is present between the primary cell walls of two cells and cements them together.

Q31. Nicotine in tobacco:

• A. Decreases the heart rate
• B. Decreases the blood pressure
• C. Block the transport or oxygen✓
• D. Paralyzes cells

Explanation: Nicotine causes your blood vessels to constrict or narrow, which limits the amount of blood that flows to your organs. Over time, the constant constriction results in blood vessels that are stiff and less elastic. Constricted blood vessels decrease the amount of oxygen and nutrients your cells receive.

Q32. Stream of chloroplasts carries the fixation of:

• A. Nitrogen
• B. Oxygen
• C. Carbon monoxide
• D. Carbon dioxide✓

Explanation: Chloroplasts are the site of photosynthesis in plant cells, where carbon dioxide (CO2) is fixed into organic molecules. The process involves light-dependent reactions in the thylakoid membranes and light-independent reactions in the stroma. The enzyme Rubisco facilitates the fixation of CO2 into glucose during the Calvin Cycle.Option A (Nitrogen): Nitrogen fixation is carried out by specialized bacteria, not chloroplasts.Option B (Oxygen): Oxygen is released as a byproduct of photosynthesis, not fixed.Option C (Carbon monoxide): Carbon monoxide is not involved in the photosynthetic process and is harmful to plants.

Q33. The valves between the right atrium and right ventricle is called:

• A. bicuspid valve
• B. tricuspid valve✓
• C. pulmonary valve
• D. semi lunar valve-

Explanation: The valve between the right atrium and the right ventricle is the tricuspid valve.

Q34. Anthocyanins are various types of colorful pigments present in the:

• A. Chloroplasts
• B. Chromoplasts
• C. Leucoplasts
• D. Vacuoles✓

Explanation: Anthocyanins are found in the cell vacuole, mostly in flowers and fruits, but also in leaves, stems, and roots

Q35. Anti-bodies are produced by:

• A. Red blood cells
• B. Platelets
• C. B-lymphocytes✓
• D. Hormones

Explanation: B-lymphocytes: B-lymphocytes, also called B-cells, are a type of white blood cell that plays a central role in the adaptive immune response. When a pathogen (like a virus or bacteria) enters the body, B-cells recognize specific antigens (molecules on the surface of the pathogen) and produce antibodies. These antibodies are proteins that bind to the antigens and help neutralize or destroy the pathogen. B-cells are essential for the immune system's ability to remember and respond to previously encountered pathogens, leading to immunity. In summary, antibodies are produced by B-lymphocytes as part of the adaptive immune response, which helps the body fight off infections and provides immunity against future encounters with the same pathogen.

Q36. Phage virus secretes an enzyme called "lysozyme" form its

• A. Head region
• B. Tail region✓
• C. Neck region
• D. Capsule region

Explanation: The phage virus uses its tail region to secrete lysozyme, an enzyme essential for breaking down the bacterial cell wall during the penetration phase of infection. This allows the phage to inject its genetic material into the host cell. The head region primarily stores genetic material, the neck region acts as a connector, and the capsule region is not applicable in this context. Therefore, the correct answer is the tail region.

Q37. Much of mechanical digestion takes place in the

• A. oesophagus
• B. mouth
• C. stomach✓
• D. duodenum

Explanation: The correct answer is the stomach. The stomach is crucial for mechanical digestion as it churns and mixes the food, breaking it down into smaller pieces and converting it into a semi-liquid form known as chyme. This process is essential for the subsequent stages of digestion. In contrast, the oesophagus is merely a passage for food, the mouth begins mechanical digestion but does not complete it, and the duodenum primarily focuses on chemical digestion and absorption rather than mechanical breakdown.

Q38. H.I.V contains

• A. two RNAs✓
• B. a single R.N.A
• C. D.N.A and R.N.A
• D. D.N.A

Explanation: HIV contains two identical RNAs enclosed within capsid

Q39. The amount of energy in food is measured as:

• A. ATP
• B. Calories✓
• C. ADP
• D. Carbohydrates

Explanation: Amount of energy in food is measured in calories.

Q40. The inheritable form of immunity through mother's milk is:

• A. active immunity
• B. innate immunity
• C. passive immunity✓
• D. acquired immunity

Explanation: Passive immunity refers to the transfer of antibodies from one individual to another, providing immediate but temporary protection. In the context of mother's milk, antibodies are passed from the mother to the infant, offering protection against infections until the infant's immune system matures. Active immunity, on the other hand, involves the body actively producing antibodies in response to an infection or vaccination. Innate immunity is the body's first line of defense present at birth, not specifically transferred from mother to child through milk. Acquired immunity is developed over time as the body encounters different antigens, which is a different process from the passive transfer of antibodies.

Q41. Which of the following is NOT an innate behavior?

• A. A mammal sucking milk
• B. A dog looking for its food dish✓
• C. A worm moving away from bright light
• D. A spider spinning a web

Explanation: The correct answer is Option B: 'A dog looking for its food dish.' This behavior is learned because dogs associate the dish with food through experience. In contrast, the other behaviors listed are innate, meaning they are instinctive and do not require learning or experience. A mammal sucking milk, a worm moving away from bright light, and a spider spinning a web are all actions that animals perform without prior learning, driven by instinctual responses.

Q42. Entamoeba belongs to the phylum:

• A. sporozoa
• B. sarcodina✓
• C. mastigophora
• D. microspora

Explanation: Entamoeba belongs to the subphylum Sarcodina, which includes protozoans that move and feed using temporary projections of their cell bodies called pseudopodia. This is unlike Sporozoa, which are non-motile and known for their spore-forming stages; Mastigophora, which use flagella for movement; and Microspora, which are spore-forming unicellular parasites.

Q43. A non-specific defense reaction to tissue damage caused by injury or infection is known as:

• A. active immunity
• B. inflammatory response✓
• C. c
• D. d

Explanation: Inflammation is a response triggered by damage to living tissues. The inflammatory response is a defence mechanism that evolved in higher organisms to protect them from infection and injury.defense

Q44. Nuclear mitosis occurs in the kingdom of

• A. Monera
• B. Protista
• C. Plantae
• D. Fungi✓

Explanation: In the kingdom Fungi, nuclear mitosis is a distinctive feature. Unlike other kingdoms, the mitotic spindle forms inside the nuclear envelope, which remains intact during mitosis. This is known as intranuclear mitosis. In contrast, in the kingdom Monera, organisms are prokaryotic and do not perform mitosis. Protista includes eukaryotic organisms that undergo mitosis, but not specifically nuclear mitosis. In the kingdom Plantae, the nuclear envelope breaks down during mitosis, and the spindle fibers form in the cytoplasm, not within the nucleus.

Q45. The protein that helps other cells resist viral infection is

• A. Penicillin
• B. Histamine
• C. Interferon✓
• D. Antigens

Explanation: Interferons are a group of signaling proteins made and released by host cells in response to the presence of viruses. They allow communication between cells to trigger the protective defenses of the immune system that eradicate pathogens or tumors. The other options are not correct: Penicillin is an antibiotic for bacterial infections, Histamine is involved in allergic responses, and Antigens are molecules that trigger immune responses, not proteins that directly resist viral infections.

Q46. Rust and smut belong to the phylum

• A. zygomycota
• B. ascomycota
• C. basidiomycota✓
• D. deuteromycota

Explanation: Rust and smut diseases are caused by fungi that belong to the phylum Basidiomycota. These fungi are known for producing complex fruiting bodies and are significant plant pathogens. The other options, Zygomycota and Ascomycota, include fungi that play different roles in the ecosystem, such as decomposing organic matter or forming mutualistic relationships. Deuteromycota, meanwhile, is an outdated classification for fungi with unknown sexual stages and does not specifically cater to rust and smut pathogens.

Q47. A network of tubules that runs through compact bone is called the

• A. Haversian canal✓
• B. Periosteum
• C. Marrow
• D. Joint

Explanation: The correct answer is the Haversian canal. These canals are part of the microscopic structure of compact bone and facilitate the transportation of blood vessels and nerve fibers throughout the dense bone structure, communicating with osteocytes. The other options are not networks of tubules: the periosteum is a tissue layer on bones, marrow is the soft tissue inside bones, and a joint is where bones connect, allowing for movement.

Q48. Club-mosses are also called

• A. Psilopsida
• B. Sphenopsida
• C. Lycopsida✓
• D. Pleropsida

Explanation: The correct answer is Lycopsida. Club-mosses belong to the class Lycopsida, which is a group of vascular plants that have microphylls and reproduce using spores. The other options, such as Psilopsida and Sphenopsida, refer to different classes of plants within the plant kingdom. Pleropsida is not a valid classification.

Q49. Hormones produced from cholestrol are called

• A. Protein hormones
• B. Non-steroid hormones
• C. Steroid hormones✓
• D. Peptide hormones

Explanation: Steroid hormones are synthesized from cholesterol and include key hormones such as testosterone, estrogen, cortisol, and aldosterone. These hormones play crucial roles in various bodily functions including metabolism, inflammation, and sexual characteristics. On the other hand, protein and peptide hormones, such as insulin and oxytocin, are made from amino acids and do not originate from cholesterol. This distinguishes them clearly from steroid hormones. Non-steroid hormones is a broader category that includes both protein and peptide hormones, further differentiating them from cholesterol-derived steroid hormones.

Q50. Lycopersicum esculenium is commonly known as

• A. Gram
• B. Tomato✓
• C. Potato
• D. Red pepper

Explanation: The correct answer is Tomato. Lycopersicum esculentum is the scientific name for the tomato plant, which is part of the nightshade family Solanaceae. The other options are different species: Gram (chickpea) is a legume, Potato is Solanum tuberosum, and Red pepper is Capsicum annuum, all unrelated to the tomato's scientific designation.

Q51. The rate of metabolism is regulated by:

• A. PTH (Parathyroid Hormone)
• B. Thyroxine✓
• C. Aldosterone
• D. Calcitonin

Explanation: Thyroxine is the hormone secreted by the thyroid gland that plays a key role in regulating the body's metabolism. It influences how the body converts nutrients into energy and impacts processes such as digestion, heartbeat, and muscle function. PTH, aldosterone, and calcitonin serve different purposes: PTH is important in calcium regulation, aldosterone regulates sodium and potassium balance, and calcitonin helps manage calcium levels, not overall metabolism.

Q52. Plant cells synthesize sugar in the;

• A. Thylakoid
• B. Grana
• C. Stroma✓
• D. Christa

Explanation: Plant cells synthesize sugar in the stroma of chloroplasts. The stroma contains the enzymes necessary for the Calvin cycle, which is the process that converts carbon dioxide and other compounds into glucose. The thylakoids and grana are involved in the light-dependent reactions that produce ATP and NADPH, which are then used in the stroma for sugar synthesis. Christa is unrelated to chloroplasts and pertains to mitochondrial structure.

Q53. The process of cell division result in:

• A. two daughter cells✓
• B. sister chromatids
• C. mitosis
• D. unregulated growth

Explanation: Cell division Mitosis or meiosis results in the formation of daughter cells from the division of the parent cell.

Q54. Chlorophyll II is protected from intense light by

• A. plant hormones
• B. carotenoids✓
• C. plant enzymes
• D. water present in mysophyll tissue

Explanation: Carotenoids are the photoprotective pigments that absorb light of high intensity and transfer the energy to chlorophyll for photosynthesis, thereby playing an important role in photosynthesis.

Q55. Malphigian tubules convert nitrogenous waste into:

• A. urine
• B. ammonia
• C. uric acid✓
• D. urea

Explanation: Malphigian tubules are specialized excretory organs found in insects like cockroaches. They convert nitrogenous waste into uric acid, a compound that can be excreted with minimal water loss. This is particularly advantageous for water conservation in terrestrial environments. Option C is correct because uric acid is the end product of nitrogenous waste processing in these tubules. Option A (urine) and Option D (urea) involve more water for excretion, which is not as efficient in conserving water. Option B (ammonia) is highly toxic and requires a lot of water to be excreted safely, making it unsuitable for organisms relying on Malphigian tubules.

Q56. Chlorosis in plants is caused by the deficiency of:

• A. nitrogen
• B. magnesium
• C. potassium
• D. both a and b✓

Explanation: Chlorosis is the yellowing of leaves due to a lack of chlorophyll, often caused by nutrient deficiencies. Nitrogen is a vital component of chlorophyll, and magnesium is part of the chlorophyll molecule. Therefore, deficiencies in nitrogen and magnesium can both result in chlorosis. Potassium, while important for various plant functions, does not directly affect chlorophyll production, so its deficiency does not typically cause chlorosis.

Q57. The changes in the biochemical composition and physiology occurring at regular intervals in 24 hours is termed as:

• A. geoannual rhythm
• B. lunar rhythm
• C. circadian rhythm✓
• D. tidal rhythm

Explanation: Circadian rhythms are intrinsic 24-hour cycles that affect physiological, mental, and behavioral functions in living organisms. These rhythms align with the Earth's rotation, resulting in predictable changes in response to light and dark cycles. The incorrect options are:Geoannual rhythm: Relates to yearly changes, not daily.Lunar rhythm: This rhythm is based on the moon's phases, approximately 29 days long.Tidal rhythm: These rhythms are dictated by tidal patterns, typically occurring over about 12 hours, not 24 hours.

Q58. The earlyis fall of leaves and fruits in plants in caused by the deficiency of:

• A. phosphorus✓
• B. potassium
• C. magnesium
• D. nitrogen

Explanation: The correct answer is phosphorus. Phosphorus is essential for the development of roots, flowers, seeds, and fruit. Its deficiency can lead to poor structural integrity and premature abscission, or the dropping of leaves and fruits. Potassium helps in the overall plant health and resistance to stresses but does not specifically prevent early leaf and fruit fall. Magnesium is crucial for chlorophyll production and photosynthesis but does not prevent abscission. Nitrogen is important for growth and green coloration but not directly involved in the prevention of early leaf and fruit drop.

Q59. The organism developed with two heads and one trunk is called:

• A. Identical twins
• B. Dizygotic twins
• C. Fraternal twins
• D. Siamese twins✓

Explanation: Siamese twins or also known as Conjoined twins. It is a very rare condition in which twins are joined side to side at the pelvis and part or all of the belly (abdomen) and chest but with separate heads. Such twins develop when an early embryo only partially separates to form two individuals.

Q60. Hydathodes are

• A. hormones secreting glands
• B. water secreting glands✓
• C. nectar secreting glands
• D. enzymes secreting glands

Explanation: Hydathodes are holes in leaf magrin through which water is secreted out during guttation.

Q61. A Punnet square is used to determine the

• A. result of mitosis
• B. result of meiosis
• C. actual outcome of a cross
• D. probable outcome of cross✓

Explanation: A punnett square is always used to determine the POSSIBLE OUTCOME of a cross and never an actual one because an actual one can never be determined priorly.

Q62. The number of chromosomes of tobacco plant are

• A. 43
• B. 1.29
• C. 0.43
• D. 24✓

Explanation: The total number of chromosomes present in a tobacco plant is 24, therefore option 'D' is correct.

Q63. During replication, which sequence of nucleotides would bond with the DNA sequence TATGA

• A. AUAGA
• B. ATACA
• C. UAUGU
• D. ATACT✓

Explanation: Nucleotides are the building blocks of nucleic acids, i.e., DNA and RNA. A nucleotide consists of a sugar molecule attached to a phosphate group and a nitrogen-containing base. The bases used in DNA are adenine (A), cytosine (C), guanine (G), and thymine (T). While in RNA, thymine (T) is replaced by uracil (U). The bases present on the two strands of DNA pair through hydrogen bonds in a specific manner. Following the above rules, T is complementary to A A is complementary to T T is complementary to A G is complementary to C A is complementary to T Thus the strand complementary to the strand containing TATGA bases should contain ATACT bases.

Q64. All the following are growth hormones, except

• A. phytohormones✓
• B. Gibberllin
• C. auxins
• D. cytokinesis

Explanation: All plant hormones are collectively known as growth hormones. They include growth promoters, e.g., auxins, cytokinins, gibberellins, etc. as well as growth inhibitors such as abscisic acid, etc. All of the options except option ‘A’ are growth hormones; thus, option ‘A’ is the correct answer. This division is further explained by the following diagram:

Q65. In grapes and mangoes, the INFLORESCENCE is

• A. panicle✓
• B. multiparous cyme
• C. capitulum
• D. umbel

Explanation: A panicle is a branched inflorescence in which each branch has more than one flower. Major examples of plants having such inflorescences are grapes and mangoes. They are shown below, respectively.

Q66. A cross between dissimilar individuals to bring together their best characteristics is called

• A. Genetic Engineering
• B. Hybridization✓
• C. Inbreeding
• D. Sequencing

Explanation: Hybridization involves the crossing of dissimilar individuals to bring together the best of both parents in the offspring. It leads to variation among species. From the above statements, the definition of hybridization corresponds to the statement of the question. Thus, option ‘B’ is correct.

Q67. Organisms that contain genes from other organism are called

• A. mutagenic
• B. transgenic✓
• C. glones
• D. sequencing

Explanation: An organism whose genome has been altered by the introduction of one or more foreign DNA molecules from another species by artificial means. This explanation corresponds to the statement of the question. Thus, option ‘B’ is the correct answer.

Q68. The ozone layer present in the

• A. troposphere
• B. stratosphere✓
• C. mesosphere
• D. atmosphere

Explanation: Ozone Layer: It is a thin part of Earth's atmosphere that absorbs almost all of the sun's harmful ultraviolet light. EARTH’S ATMOSPHERIC LAYERS: Earth's atmosphere has a series of layers, each with its own specific traits. Moving upward from ground level, these layers are called the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. The Ozone layer is around 15–30 km above the earth's surface. From the above diagram, we know that this region lies in the stratosphere. Thus, option ‘B’ is correct.

Q69. An inherited characteristic that increases an organism's ability to survive and produce in its specific environment is called

• A. Radiation
• B. Adaptation✓
• C. Vestigial organ
• D. Speciapion

Explanation: Inheritance characteristics refer to traits that are passed from parent to offspring during reproduction. Adaptation is any heritable trait that helps an organism, such as a plant or animal, survive and reproduce in its environment.

Q70. C.F.C gases are produced from

• A. burning of coal✓
• B. burning of charcoal
• C. automobile engines
• D. refrigeration and air conditioning

Explanation: Chloroflorocarbons are nontoxic, nonflammable chemicals containing atoms of carbon, chlorine, and fluorine. They react with the ozone and destroy it, making the layer thinner and allowing ultraviolet (UV) radiation to pass through it and fall on the earth's surface. This UV radiation can cause skin cancer and other ailments in humans and also affect plants and animals. The main source of CFC production is Coal combustion i.e. burning of coal. Among the given options, option A is correct because, unlike the rest, CFCs are released into the atmosphere, not produced.

Q71. The area where ultra voilet radiations are intense is the

• A. Alphine forests
• B. Boreal forests
• C. Arctic tundra
• D. Alpine tundra✓

Explanation: Among all the options, alpine tundra is at the highest elevation (about 12000 ft and above), and it has the most sunlight hours. Thus, the UV level in the alpine tundra is the highest.

Q72. A woman is homozygous for A negative blood type. A man has an AB-negative blood type. What is the probability that tha couples child will be type B negative?

• A. 0%✓
• B. 25%
• C. 50%
• D. 75%

Explanation: There is zero possibility that their offspring will have a B-negative blood type

Q73. A bird's wings are homologous to

• A. fishes tail fin
• B. dog's front legs✓
• C. mosquitoes wings
• D. alligator's claws

Explanation: Homologous Organs: These organs have similar anatomical structures but perform different functions. They are the result of divergent evolution. A human's arm, a dog's leg, a bird's wing, and a whale's flipper are all homologous. The same bones are found in each structure; they only differ in their size and shape.

Q74. All of the following are derived from mesoderm except:

• A. Muscles
• B. Liver✓
• C. Gonads
• D. Blood vessels

Explanation: GERM LAYERS: A germ layer is a group of cells in an embryo. There are 3 germ layers: the endoderm (inner layer), the ectoderm (outer layer), and the mesoderm (middle layer). All the parts mentioned are formed by mesoderm except for the liver, which is a product of endoderm.

Q75. The diameter of Histone is

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

Explanation: A histone is a protein that provides structural support to a chromosome. It is composed of mostly positively charged amino acid residues such as lysine and arginine. Histone is approximately 2 nm wide.

Q76. What is the most important source of water pollution in Pakistan?

• A. Industries
• B. Transportation
• C. Mining Industry
• D. Agricultural and municipal wastage✓

Explanation: Contamination of water bodies is called water pollution. Pakistan is an agricultural country. The root cause of water pollution in Pakistan arises here. The farmers use tons of water for their fields and crops and then dump all the contaminated water into lakes and rivers. In addition to that, the municipal committees are least bothered about the pollution caused by the garbage they throw in the water bodies. The industries also play a role in this, but the formerly mentioned points are the main causes of destruction. Thus, we will go for option D.

Q77. The number of nitrogenous bases common in both DNA and RNA are

• A. 2
• B. 3✓
• C. 5
• D. 4

Explanation: Building blocks of nucleic acids, i.e., DNA and RNA. A nucleotide consists of a sugar molecule attached to a phosphate group and a nitrogen-containing base. The bases used in DNA are adenine (A), cytosine (C), guanine (G), and thymine (T). In RNA, thymine (T) is replaced by uracil (U). Thus, adenine, cytosine, and guanine are common in DNA and RNA.

Q78. The genetic potential for one type of cell from a multicellular organism to generate a whole new organism is called

• A. unipotent
• B. multipotent
• C. totipotent✓
• D. pluripotent

Explanation: Totipotent is an immature cell that is capable of giving rise to any cell type or even a complete embryo.

Q79. Which sequence correctly describes the route sperm take through the human male reproductive system?

• A. Vas deferens, urethra, epididymis
• B. Epididymis, vas deferens, urethra✓
• C. Epididymis, urethra, vas deferens
• D. Urethra, epididymis, vas deferens

Explanation: The correct sequence of sperm transport is: Epididymis → Vas deferens → Urethra. Sperm is stored and matured in the epididymis, then it travels through the vas deferens during ejaculation, and finally exits the body through the urethra. The other options are incorrect because they either misplace the sequence or start with an incorrect part of the pathway.

Q80. In chlorophyll 'a', the group attached to prophyrine ring is

• A. hydroxyl group
• B. methyl group✓
• C. carboxyl group
• D. aldehyde group

Explanation: Chlorophyll 'a' is an essential pigment in photosynthesis, and its structure includes a porphyrin ring. Attached to this porphyrin ring is a methyl group (CH3). This is a distinguishing feature of chlorophyll 'a' as opposed to chlorophyll 'b', which has a formyl group instead. The hydroxyl, carboxyl, and aldehyde groups are not part of chlorophyll 'a's core structure.

Q81. The anion size are larger than its atomic size because:

• A. The addition of an electron increases the volume of the electron cloud
• B. It increases the effective nuclear charge
• C. The repulsion between electrons increases with the addition of electrons✓
• D. The attraction between electrons and the nucleus increases

Explanation: The correct answer is that the repulsion between electrons increases with the addition of electrons. When an anion is formed, an extra electron is added to the atom. This leads to increased electron-electron repulsion, which outweighs the attraction between the nucleus and the electrons, causing the electron cloud to expand and making the anion larger than its parent atom. Option A is incorrect because the volume increase is due to repulsion, not just more space. Option B is incorrect because the effective nuclear charge remains the same. Option D is incorrect because the net attraction does not increase; rather, the repulsion is the dominant factor.

Q82. Which one would you class it as more metallic in character?

• A. As
• B. Bi✓
• C. C
• D. Sb

Explanation: Metallic character refers to an element's ability to lose electrons. It increases as you move down a group in the periodic table because the atomic radius becomes larger, allowing for easier electron loss due to increased shielding and decreased ionization energy. Conversely, metallic character decreases across a period from left to right as the effective nuclear charge increases, holding electrons more tightly. In this question, bismuth (Bi) is the most metallic because it is further down the group compared to arsenic (As) and antimony (Sb), and it is also more metallic than carbon (C), which is a non-metal. This makes Bi the element with the highest tendency to lose electrons among the given options.

Q83. Hydration energy is the heat evolved or absorbed when:

• A. one mole of gaseous ions is dissolved in one mole of water
• B. one mole of ions in solid state is dissolved in one mole of water.
• C. one mole of gaseous ions is dissolved in water to give infinitely dilute solution✓
• D. one mole of ions in solid state is dissolved to form concentrated solution

Explanation: Hydration energy is defined as ‘the energy released when one mole of gaseous ions dissolves in water to give an infinitely dilute solution’. Infinitely dilute solution can be defined as the term in which a solution contains so much solvent that if one adds more solvent to it, there will be no change in the concentration of the solution. Attraction occurs between the water molecules and the ions of the solute, and the solute particles interact only with the solvent, not each other. Hydration energy is always negative, meaning it is exothermic and energy is always released.Option A is incorrect as an excess amount of water is required.

Q84. The behavior of PbCl and PbCl2 respectively are:

• A. ionic and covalent✓
• B. covalent and ionic
• C. covalent and coordinate covalent
• D. ionic and coordinate covalent

Explanation: The correct answer is 'ionic and covalent'. PbCl₂ is ionic because lead is in a +2 oxidation state, leading to electron transfer and ionic bond formation with chlorine. In contrast, PbCl4 is covalent because lead is in a +4 oxidation state, which increases its polarizing power, favoring electron sharing and covalent bond formation. Options B, C, and D are incorrect as they either reverse the bond types or incorrectly identify the bond types in PbCl₂ and PbCl4.

Q85. Select the correct order in ionic behavior:

• A. AlF3 > AlBr3 > AlCl3 >> AlF3
• B. AlCl3 > AlF3 > AlBr3 > AlI3
• C. AlCl3 > AlBr3 > AlI2 > AlF3
• D. AlF3 > AlCl3 > AlBr3 > AlI3✓

Explanation: The order of ionic character is determined by the size of the halide ions. According to Fajan's rule, smaller anions like F- lead to more ionic character, while larger anions like I- lead to more covalent character. Thus, AlF3 with the smallest fluoride ion is the most ionic, followed by AlCl3, AlBr3, and finally AlI3, which is the least ionic due to the large size of the iodide ion.Options A, B, and C incorrectly order the compounds, either by overlooking the size trend or by making typographical errors.

Q86. Select the most stable covalent hycride:

• A. BiH3
• B. NH3
• C. HF✓
• D. SbH3

Explanation: The most stable hydride will have the greatest electronegativity difference since the bond energy will then also be the greatest. Fluorine is the most electronegative element so it's electronegativity difference with hydrogen will be the greatest and it will be most stable as there will be greatest electrostatic attraction between hydrogen and fluorine

Q87. Potassium is found in nature as carnallite, its composition is:

• A. KAlSi3O8
• B. KCl·MgCl2·6H2O✓
• C. KCl
• D. KCl·Al2O3·2H2O

Explanation: Carnallite is a hydrated potassium magnesium chloride mineral with the chemical formula KCl·MgCl2·6H2O. It contains both potassium and magnesium ions, distinguishing it from other potassium minerals like sylvite (KCl) that do not contain magnesium or water of crystallization. Option B accurately represents the chemical composition of carnallite. The other options either omit important components or include incorrect elements.

Q88. Fajan's rule states that small, highly charged ions tend to form more:

• A. ionic compounds
• B. polymeric compounds
• C. covalent compounds✓
• D. coordination compound

Explanation: Fajan's rule explains that small, highly charged ions have high polarizing power due to their charge density. This leads to greater distortion of the electron cloud of the anion, increasing the covalent character of the bond. Hence, they tend to form covalent compounds. Option A, ionic compounds, is incorrect because such ions form bonds with significant covalent character rather than purely ionic bonds. Option B, polymeric compounds, is unrelated to Fajan's rule, which focuses on the nature of individual ionic bonds, not polymerization. Option D, coordination compounds, involves complex formation and ligand interactions, which are not directly addressed by Fajan's rule.

Q89. Beryllium, a member of alkaline earth metal, is almost as hard as:

• A. calcium
• B. Potassium
• C. iron✓
• D. magnesium

Explanation: The Mohs scale of mineral hardness is used to compare the scratch resistance of different minerals. Beryllium has a Mohs hardness of 5.5, making it relatively hard among metals. Iron, with a hardness of 4, is the closest in hardness to beryllium among the options provided. Calcium, potassium, and magnesium all have significantly lower hardness values, making them incorrect choices when comparing their hardness to beryllium.

Q90. Select the correct statement:

• A. Cholera, typhoid, and tetanus are well-known diseases caused by viruses.
• B. Dinoflagellates, euglenoids and slime moulds are placed under kingdom Monera
• C. Members of kingdom Protista are primarily aquatic✓
• D. Dinoflagellates are the chief 'producers' in the oceans

Explanation: The kingdom Protista consists of a diverse group of eukaryotic microorganisms, many of which are found in aquatic environments. Protists can be found in freshwater, marine habitats, and even moist terrestrial environments. They include various organisms such as algae, protozoa, and slime moulds.

Q91. Refratory bricks used for furnace lining are formed by mixing and drying:

• A. MgO and clay✓
• B. MgCO3 and clay
• C. MgSO4 and clay
• D. MgCO3 and CaCO3

Explanation: Refractory materials can withstand high temperatures. Refractory bricks are used in lining furnaces, kilns, fireboxes, and fireplaces. They are made by mixing MgO and clay.

Q92. The electronegativity of the [1]A element first decreases and then increases. This behavior is due to poor shielding of:

• A. S electron
• B. p - electron
• C. d- electron✓
• D. f - electron

Explanation: Electronegativity is the tendency of an atom to attract electrons. In group 1 elements, as we go down the group, the atomic size increases due to the addition of electron shells, which generally decreases electronegativity. However, the presence of d electrons, which are less effective at shielding the nuclear charge, can cause variations. These d electrons have a higher energy level and are more dispersed, leading to poor shielding and causing a temporary increase in electronegativity. The other options are incorrect because s and p electrons provide more effective shielding, and f electrons typically affect elements outside the context of group 1.

Q93. Sodium tetrabora e Na2B4O7.10H2O is

• A. Colemanite
• B. Borax✓
• C. Diaspore
• D. bauxite

Explanation: The given formula, Na2B4O7.10H2O is that of borax.

Q94. The above reaction is slow at the start but speeds up after some time. This is because of:2.41 (s) + NaOH (aq) + 2H2O ------- 2NaAlO2 + 3H2

• A. The reaction is exothermic and the heat generated speeds up the reaction
• B. The hydrogen liberated during the reaction acts as a catalyst
• C. The protective oxide layer of the aluminum dissolves and the meal surface is exposed to the reactant✓
• D. Sodium aluminate is highly soluble; therefore, it helps the reaction move in the forward direction

Explanation: Aluminium has a protective coat, due to which it initially reacts slowly. After a while, this coat dissolves, causing the reaction to speed up due to the increased exposed surface area of aluminum. The generation of heat increases the temperature. So if the reaction was exothermic, an increase in temperature would cause the reaction to move in a backward direction. A catalyst cannot be consumed or produced in a reaction, and hydrogen gas is being produced here, so it cannot be a catalyst. Solubility is not related to the speed of reaction.

Q95. Sodium carbonate, when fused with sand, forms sodium silicate, which is commonly known as

• A. Soda glass
• B. Water glass✓
• C. Jinna glass
• D. Pyrex glass

Explanation: Sodium silicate is commonly known as water glass, or soluble glass. It gets its name because it is essentially glass (silicon dioxide) in water. As the water evaporates, the solution solidifies into a glassy solid. It's formula is Na2SiO3. Soda glass is a mixture of Na2SiO3 and CaSiO3. There is no such thing as Jinna glass. Pyrex glass was originally made of borosilicate glass, which is very resistant to thermal shock. Currently, Pyrex is made of soda-lime glass. It can withstand abrupt changes in temperature and does not break on heating.

Q96. Silicones are resisted to chemical attack and are used as

• A. Painta✓
• B. Venshes
• C. Water proofing fabrics
• D. All of the above

Explanation: Silicon is used in Paints as it improves adherence, waterproofing and resistance to chemicals.

Q97. Select the oxide, which is in the solid state at room temperature:

• A. N2O5✓
• B. N2O
• C. NO2
• D. N2O3

Explanation: N2O5 is solid at room temperature.

Q98. Group 5th elements arsenic and antimony are considered as:

• A. metallic
• B. Non-metallic
• C. metalloids✓
• D. transition elements

Explanation: These two are Metalloids because they do not conduct electricity but are metals.

Q99. The formula for mustard gas is:

• A. (C2H2Cl2)2S
• B. (C2H4Cl2)2S
• C. (C2H3Cl2)2S
• D. (C2H4Cl)2S✓

Explanation: The correct formula for mustard gas is (C2H4Cl)2S. Mustard gas is a sulfur mustard with each carbon chain containing one chlorine atom, which is characteristic of its chemical structure. Option A is incorrect because it has two chlorine atoms per carbon, which is not the case for mustard gas. Option B is also incorrect as it suggests two chlorine atoms per carbon chain, unlike mustard gas. Option C is wrong because it indicates three hydrogen atoms per carbon, differing from the actual chemical structure of mustard gas.

Q100. All gases below are monoatomic except:

• A. H✓
• B. He
• C. Ne
• D. Xe

Explanation: Hydrogen is the only gas listed that is diatomic, meaning its molecules consist of two atoms (H2). The other gases, helium (He), neon (Ne), and xenon (Xe), are all noble gases and exist as single, monoatomic entities. This is due to their stable electron configurations, which do not easily form compounds or molecules under standard conditions.

Q101. Choose the correct name of Ba₂XeO:

• A. Barium Xenate
• B. Barium Xenthate
• C. Barium Prexenate
• D. Barium Perxenthate✓

Explanation: The correct name for Ba2XeO is Barium Perxenthate. The prefix 'per-' indicates a high oxidation state of xenon, which is consistent with the structure of the compound. The other options either use incorrect prefixes or are not recognized terms in chemical nomenclature.

Q102. The electronic configuration of Cu(29) is:

• A. 1s2 2s2 2p6 3s2 3p6 3d10 4s1✓
• B. 1s2 2s2 2p6 3s2 3p6 3d9 4s2
• C. 1s2 2s2 2p6 3s2 3p6 3d8 4s2
• D. 1s2 2s2 2p6 3s2 3p6 3d9 4s2

Explanation: Cu(29)= 1s2 2s2 2p6 3s2 3p6 4s1 3d10

Q103. The oxidation power of halogen depends upon:

• A. energy of dissociation
• B. electron affinity of atoms
• C. hydration energies of lons
• D. all of the above✓

Explanation: The halogens D are good oxidizers The oxidizing power of halogens in an aqueous medium depends on their electron affinity, bond dissociation energy, and heat of hydration.

Q104. All compounds are organic except

• A. (H₂N)2CO
• B. NH4CNO✓
• C. CH₂NO₂
• D. CH4

Explanation: The correct answer is ammonium cyanate (NH4CNO), which is not considered an organic compound as it lacks carbon-hydrogen (C-H) bonds, a fundamental characteristic of organic chemistry. In contrast, urea (H₂N)₂CO, CH₂NO₂, and methane (CH4) all contain C-H bonds, thus categorizing them as organic compounds. The absence of C-H bonds in ammonium cyanate distinguishes it as inorganic.

Q105. The oxidation number of cobalt in [Co(en)2H2O(CN)]2+:

• A. 2
• B. 3✓
• C. 4
• D. 5

Explanation: The charge on EN is 0. The charge on the water is 0, the charge on CN is -1, and the charge on the complex is +2. For the central atom, consider that the oxidation number of Co is x. Therefore, the oxidation number of Co is +3.

Q106. Ammonium hydroxide was added to a salt solution, and a deep blue color was obtained. The solution contains ions of:

• A. Zn2
• B. Cu2✓
• C. Fe
• D. Ba+2

Explanation: Reaction is CuSO4+2NH4OH—---> (NH4)2SO4 +Cu(OH)2 The solution contains Cu2+ ions.

Q107. The color of coordination compound bisdimethylglyoxime nickel (11) is:

• A. red✓
• B. blue
• C. orange
• D. black

Explanation: Nickel bis(dimethyl glyoximate) is the coordination complex with a bright red colour.

Q108. Choose the compound tetraamine aqua chloro cobalt (III) chloride:

• A. Co(NH3)4H2O(Cl2-2)Cl3-3
• B. Co+2(NH3)4H2O(Cl2-2)Cl3-3
• C. Co(NH3)4H2O(Cl2-2)Cl3-3
• D. [Co(NH3​)4​(H2​O)Cl]Cl2✓

Explanation: Tetraammineaquachlorocobalt (III) chloride →[Co(NH3​)4​(H2​O)Cl]Cl2

Q109. The conversion of carbonate to urea is:

• A. Slow and exothermic
• B. Fast and exothermic
• C. Slow and endothermic✓
• D. Fast and endothermic

Explanation: The correct answer is that the conversion of carbonate to urea is slow and endothermic. This means that the reaction takes place over a prolonged period and absorbs heat energy from its surroundings. The reaction requires energy input to break bonds in the reactants and form new bonds in the product. The incorrect options either wrongly describe the energy change as exothermic or incorrectly describe the reaction speed as fast.

Q110. Vehicular emissions, that are the major environmental concern, is

• A. CO2✓
• B. CO
• C. Low hydrocarbons
• D. All of them

Explanation: CO2 is the major vehicular emission responsible for causing the greenhouse effect and environmental pollution.

Q111. Tetraethyl lead (C2H2)4Pb is used as an antoknock agent and abandoned because of its hazardous product during the combustion of fuel. The hazardous product is

• A. CO2
• B. CO
• C. Lead✓
• D. Free radica ethyne (C2H2)

Explanation: TEL can cause chronic lead poisoning, and hence its hazardous product is lead.

Q112. Select the formula of 2-methyl pentane:

• A. C3H12
• B. C5H16
• C. C6H12
• D. C6H14✓

Explanation: The formula for 2-methyl pentane is C6H14.

Q113. In the reforming process, open-chain hydrocarbons are converted into:

• A. Polymers
• B. Branched-chain hydrocarbons✓
• C. Ring hydrocarbons
• D. Branched and ring hydrocarbons

Explanation: Reforming is also called AROMATIZATION and is a process in which open-chain hydrocarbons are converted into branched-chain hydrocarbons

Q114. An organic compound after fusion with sodium gives a white precipitate when concentrated nitric acid and then silver nitrate solution are added to the filtrate. The compound is likely to be

• A. CH3CH2CHO
• B. CH3CH2CH2OH
• C. CH3CH2COOH
• D. CH3CH2CH2Br✓

Explanation: This is called Lalaigne’s test, which is done for the detection of halogens. While all the other options given do not have halogens.

Q115. Ethyne has a total of:

• A. one sigma bond, two pi bonds
• B. one sigma bond, four pi bonds
• C. two sigma bonds, four pi bonds
• D. three sigma bonds, two pi bonds✓

Explanation: Hence ethyne has one sigma bond formed by carbon carbon over lapping and the other two sigma bonds are formed by carbon hydrogen overlapping while two pi bonds are formed by side to side overlapping of py and pz orbitals.

Q116. Choose the correct option:

• A. Please bring litre of milk from nearest milk shop
• B. Please bring a litre of milk from the nearest milk shop✓
• C. Please bring a litre of milk from nearest milk shop
• D. Please bring the litre of milk from the nearest milk shop

Explanation: "Please bring a litre of milk from the nearest milk shop."This option correctly uses the indefinite article "a" before "litre of milk" and the definite article "the" before "nearest milk shop," making it grammatically correct; "Please bring a litre of milk from the nearest milk shop."This option is the best because it correctly uses the indefinite article "a" for "litre of milk" and the definite article "the" for "nearest milk shop," ensuring grammatical correctness and clarity.

Q117. carbon-carbon double bond as compared to a single bond is:

• A. Less susceptible to oxidation
• B. More susceptible to oxidation✓
• C. Equally susceptible to oxidation
• D. All of these

Explanation: A carbon-carbon double bond represents unsaturation, while a single carbon-carbon bond represents saturated hydrocarbons, alkanes that are generally unreactive; alkenes, on the other hand, are more reactive and hence more susceptible to oxidation than alkanes.

Q118. Which of the following is a nucleophil?

• A. AICI3
• B. CN✓
• C. H3O
• D. BF3

Explanation: AlCl3, H3O+ and BF3 are electrophiles, while CN is a nucleophile.

Q119. Select the most stable carbonium ion:

• A. +CH3
• B. +CH3CH₂
• C. (CH3)2 +CH
• D. (CH3)3C+✓

Explanation: Option D represents a tertiary carbonium ion, which is much more stable than primary or secondary carbonium ions.

Q120. Water is said to be permanently hard when it contains:

• A. carbonates of Ca2+ and Mg2+ ions
• B. Bicarbonates of Ca2+ and Mg2+ ions
• C. sulphates of Na+ and Mg2+ ions
• D. chlorides of Ca2+ and Mg2+ ions✓

Explanation: The presence of soluble salts of calcium and magnesium, i.e., sulfates and chlorides of calcium and magnesium, causes permanent hardness in the water.

Q121. A buffer solution containing H2CO3 and NaHCO3 is to be prepared to maintain a pH of 7.00. What must be the ratio NaHCO3 in order to realize such a pH if Ka of carbonic HCO3 acid is 4.3 x 107?

• A. 43
• B. 48
• C. 0.43
• D. 4.3✓

Explanation: pH=pKa+ Log NaHCO3/H2CO3 7=4.3*10^-7+ Log NaHCO3/H2CO3 Log NaHCO3/H2CO3=7 NaHCO3/H2CO3=10^7 NaHCO3=10^7* H2C03 NaHCO3=10^7*4.3^-7 NaHCO3=4.3

Q122. A sample containing aluminum weighing 10.0g yielded 2.0g of aluminum sulphide. What is the percentage of aluminum (atomic mass 27.0) in the sample? Sulphur (atomic mass 32.0) =

• A. 2.0 X27/150 x100✓
• B. 2.0/10 X 2 X 27/150 X 100
• C. 2.0/10 X 27/1500 X 100
• D. 2.0/10 X 150/3 X 27 X 100

Explanation: Mass of aluminum in formula: 2×27=54 gMolar mass of Al₂S₃: 2×27+3×32=54+96=150 g54/150x100=36%

Q123. Choose the region of the spectrum which would be used to determine the structure of crystalline solids:

• A. visible
• B. infrated
• C. X rays✓
• D. ultraviolet

Explanation: To determine the structure of crystalline solids, the spacing between the atoms of crystal (i.e. in the order of 10¹⁰ or degree angstroms Å) should correspond to the wavelength of the region of the spectrum used. Its wavelength is on the order of 10⁻¹² to 10⁻⁸.This wavelength range corresponds to the spacing between atoms of crystal. Thus, option C is correct.

Q124. The temperature at which domains of the ferromagnetic substance disorient is:

• A. critical temperature
• B. absolute temperature
• C. Curie Temperature✓
• D. normal temperature

Explanation: Ferromagnetic MATERIALS can be permanently magnetized. Curie Temperature: The temperature at which the ferromagnetic element starts to lose its magnetism and becomes paramagnetic. Understanding the above-stated facts, option ‘C’ is the correct answer.

Q125. .Which one of the following most closely resembles an ideal gas?

• A. Xe
• B. H2
• C. CO2
• D. He✓

Explanation: Helium is an inert gas that exists as a single atom, resulting in the lowest conceivable van der Waals dispersion forces. It occupies an approximately negligible volume and possesses a very tiny mass. It is also highly compressible. Because of all of these properties, helium is the most ideal gas. Properties of Ideal Gas: The particles of gas have negligible volume and mass. They are equally sized. They are compressible. They are always in motion, colliding elastically within a container with no energy loss. They take the shape of the container. They behave inertly, i.e., they do not have intermolecular forces.

Q126. According to molecular orbital theory, which of the following is most unstable molecule?

• A. He2+
• B. H2-
• C. H2+
• D. H2-2✓

Explanation: MOLECULAR ORBITAL THEORY: It states that all the atoms tend to combine together and form molecular orbitals. It is basically a method for describing the electronic structure of molecules using quantum mechanics. The number of electrons present in all four options is shown below : We know that, greater the number of electrons present in an atom, the more unstable it is. Here, H₂⁻² has the maximum number of electrons. Thus, it is most unstable.

Q127. How many grams of waster are produced in burning 2.24dm of hydrogen at STP?

• A. 180g
• B. 81g
• C. 1.8g✓
• D. 0.18g

Explanation: The solution for this question is given below:

Q128. 50 cm of KOH solution was titrated against 1.0M HCIusing phenolphthalein as an indicator. The acid used was found to be 7,5 cm. the concentration of KOH solution is:

• A. 0.15 M✓
• B. 1.5 M
• C. 0.75
• D. None

Explanation: The calculations are shown below : The chemical equation used in this titration is : HCl+KOH→KCl+H₂O In this chemical reaction, the molar ratio between HCl and KOH is 1:1. So, moles of HCl = moles of KOH Mʜᴄʟ × Vʜᴄʟ = Mᴋᴏʜ × Vᴋᴏʜ Mʜᴄʟ × Vʜᴄʟ ----------------- = Mᴋᴏʜ Vᴋᴏʜ (placing values) 1 × 7.5 ------------ = Mᴋᴏʜ 50 Mᴋᴏʜ = 0.15M

Q129. Choose the least inert gas:

• A. Helium
• B. Neon
• C. argon
• D. Xenon✓

Explanation: All of the noble gases are completely inert except for xenon. Under normal conditions, xenon is non-reactive, but at extreme temperatures and pressures, it covalently bonds to fluorine, oxygen, nitrogen, and carbon. Three fluorides of xenon are known: XeF2, XeF4, and XeF6 Although it has a complete outer shell, due to its highly reactive behavior, xenon is considered the least inert gas. Thus, Option ‘D’ is correct.

Q130. Uranium-235 decays to thoriun+ 234 by the process of

• A. fission
• B. beta decay
• C. alpha radiation✓
• D. gamma radiation

Explanation: URANIUM-238 : Mass number : 238 Atomic number : 92 THORIUM-234 : Mass number : 234 Atomic number: 90 From above, it is clear that mass number decreases by 4 and atomic number decreases by 2. That’s exactly what happens in alpha decay so option ‘C’ is the right answer.

Q131. The hydrolysis of an ester proceeds most slowly under the conditions of:

• A. high acidity
• B. high basicity
• C. neutrality✓
• D. high temperature

Explanation: An ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group (−OH) is replaced by an alkoxy group (−O−R). The hydrolysis of esters is catalyzed by either an acid or a base. The first step involved in this reaction is the breakage of the C=O bond . In case of an acid, the proton from the acid attacks on it and breaks it and in case of base, a hydroxide ion attacks and forms a new species. In a neutral solution, there is no species to break the bond. Thus, in a neutral solution, the hydrolysis is too slow, and as a result, it is normally avoided.

Q132. If an atom exists in the excited state n = 5, the maximum number of transitions that take place are:

• A. 6
• B. 5
• C. 10✓
• D. 3

Explanation: To solve such a question, here’s an amazing trick! We know that n is 5. Step 1: From the ‘n’ value, start counting backwards. i.e. 5 4 3 2 1 Step 2 : Now drop the ‘n’ value and add the rest of the numbers, i.e. 4+3+2+1 = 10 That’s your answer!

Q133. Which one of the following is strongest acid?

• A. FCH COOH✓
• B. CH3COOH
• C. CICH COOH
• D. C6H5CH,COOH

Explanation: Electronegativity increases the acidity by increasing the ionic character of O-H. Electronegativity decreases in the order F > Cl > Br, and hence the acidic effect also decreases in the same order. Here and overall, fluorine is the most electronegative element. Thus, it is most acidic.

Q134. The situation in which the excited state i.e. metastable state contains morestate,i.e., thestate, electrons than the ground is called:

• A. ionized state
• B. stimulations
• C. population inversion✓
• D. all of these

Explanation: GROUND STATE: The ground state of an electron, the energy level it normally occupies, is the state of lowest energy for that electron. METASTABLE STATE: It is a particular excited state of an atom that has a longer lifetime than the ordinary excited states and that generally has a shorter lifetime than the ground state. Population inversion occurs when more electrons in a particular situation are in a higher-energy state than in a lower-energy state. Hence, option C is correct.

Q135. Which one of the following would you suggest to locate the position of the double bond between carbon atoms in an organic compound?

• A. Addition of bromine water
• B. Addition of HI
• C. Oxidation with ozone✓
• D. All of the above

Explanation: Ozonolysis, i.e., oxidation with ozone, is the method used to point out the position of a double bond in an organic compound. Thus, option ‘C’ is the correct answer.

Q136. Most of the oxides of non-metals combine with water to form:

• A. hydrogen gas
• B. salt and water
• C. a base
• D. An acid✓

Explanation: Non-metals are the elements that form negative ions by accepting or gaining electrons. Oxides of non-metals combine with water to form acids. For example, sulfur and nitrogen are non-metals. Their oxides are sulfur dioxide and nitrogen oxide, respectively. When they combine with water, they form sulfuric acid and nitric acid. These are responsible for acid rain.

Q137. In which of the following atoms, the Is orbital is the smallest in size?

• A. bromine
• B. chlorine
• C. fluorine
• D. iodine 200✓

Explanation: For all elements in general, the higher the atomic number, the smaller the 1s orbital. The 1s orbital is closest to the nucleus. Therefore, it is mostly in the nucleus’s positive electrostatic field. The greater the atomic number, the greater the number of electrons in the outer shells, and thus, the greater the electrostatic force between the nucleus and electrons. Now, among all the halogens, iodine has the highest atomic number (127). Thus, the first orbital of iodine is the smallest.

Q138. The highest oxidation state of manganese-3s72 3p 3d5+4S2 in its compounds is:

• A. +2
• B. +5
• C. +7✓
• D. +8

Explanation: The highest oxidation state of manganese in its compounds is +7. In this oxidation state, manganese forms compounds like potassium permanganate (KMnO4), which is a powerful oxidizing agent commonly used in various chemical processes and laboratory applications.

Q139. The bleaching action of bleaching powder is due to "available chlorine". It is the amount of chlorine

• A. that is required for the preparation of bleaching powder
• B. site free when excess of sulphuric acid is added to the bleaching powder
• C. that is required for the generation of hypochlorine✓
• D. Both B and C

Explanation: The bleaching action of bleaching powder is due to the release of "available chlorine" when it comes into contact with an acidic substance, like sulfuric acid. When bleaching powder (calcium hypochlorite, Ca(ClO)2) is treated with an acid, it decomposes to release hypochlorous acid (HClO) and calcium sulfate (CaSO4). Hypochlorine acid is the active bleaching agent responsible for its bleaching properties.

Q140. The angle subtended at the centre of a sphere by its surface area is equal to:

• A. 4/3 π radian
• B. 4/3 π steradian
• C. 4 π radian
• D. 4 π streradian✓

Explanation: One steradian is the solid angle of a sphere subtended by a portion of the surface whose area is equal to the square of the sphere’s radius. The complete surface area of a sphere= 4πr² so the total solid angle about a point = 4πr²/r² = 4π steradian The steradian is the unit of solid angles. It is used in 3D geometry. Whereas the radian is used in planar geometry so options A and C are ruled out as we are dealing with a 3D cone here. (The mention of surface area in the question implies that 3D geometry is involved)

Q141. MLT are are the dimersions of

• A. strain
• B. refractive index
• C. magnification
• D. All of these✓

Explanation: The given dimensions indicate a dimensional quantity. Strain = change in length/original length [L]/[L] =1 so it is dimensionless Refractive index = velocity of light in medium 1/ velocity of light in medium 2 [LT-1]/[LT-1]=1 so it is dimensionless Magnification=Image length/ Object length [L]/[L] = 1 so it is dimensionless As all these quantities have no dimensions, option D is correct.

Q142. The magnitude of the resultant of two forces is 2F. If the magnitude of each force is F. Than the angle between these forces is:

• A. 0°✓
• B. 90°
• C. 120°
• D. 180°

Explanation: Both vectors have the same magnitude, F, and the resultant is F+F = 2F. If two vectors have the same direction, then the resultant vector is the algebraic sum of the two vectors, as in this case. The vectors must therefore also have the same direction, making the angle between them 0°. The resultant is at it's greatest value when the angle between the vectors is 0°. Options B and C are incorrect, as in these cases their resultant would be a value less than 2F. Option D is incorrect as vectors are in opposite directions when angle between them is 180° so the resultant is the algebraic difference between the two, F-F = 0.

Q143. Axis equal to:

• A. 4
• B. Zero✓
• C. 2
• D. 1

Explanation: From the given diagram: i x j= k j x k= i k x i= j j x i = -k k x j= -i i x k= -j Now to solve the given expression, k x j= -i so j x -i = 0 , since these two vectors are perpendicular and the dot product of two perpendicular vectors is 0.

Q144. Three vactors of equal magnitude are acting on the three sides of an equilateral triangle. The magnitude of their resultant is:

• A. zero✓
• B. 3
• C. √3
• D. 1.73

Explanation: The three vectors act as shown in the diagram above. According to the head-to-tail rule, the resultant is obtained by joining the head of the last vector to the tail of the first vector. Therefore, the resultant vector obtained is zero.

Q145. The physical quantity which produces angular acceleration in the body is

• A. Force
• B. Moment of inertia
• C. Impulse
• D. Torque✓

Explanation: Torque is a measure of the force that can cause an object to rotate about an axis. Just as force is what causes an object to accelerate in linear kinematics, torque is what causes an object to acquire angular acceleration

Q146. The point at which an applied force produces linear motion but no rotatory Motion is:

• A. Mid-point
• B. Center of gravity✓
• C. Optical center
• D. Pole

Explanation: The point at which an applied force produces linear motion but no rotational motion is the "center of gravity." The center of gravity is the point within an object or system where the weight is evenly distributed in all directions. When an applied force is directed through the center of gravity, it results in pure linear motion without causing the object to rotate.When an external force is applied to an object, it causes translational (linear) motion when applied through the center of gravity. However, if the force is applied away from the center of gravity, it can create both linear motion and rotational motion, causing the object to pivot or rotate.The center of gravity is a critical concept in physics, particularly in mechanics and the study of equilibrium. It plays a role in determining stability, balance, and the response of an object to applied forces.

Q147. A ball is thrown vertically upward with a velocity of 98 m/s. if it takes 10 seconds to reach the highest point then the acceleration of the ball is:

• A. 9.8 m/s²
• B. 980 m/s
• C. 98 m/s²
• D. -9.8 m/s✓

Explanation: Using the first equation of motion: v = u + at final velocity(v) =0m/s initial velocity (u) =98m/s time (t) = 10 acceleration (a) = ? 0=98+10a -98=10a a=-9.8m/s²

Q148. A man throws a ball vertically upward in the compartment of an accelerated train. The ball will fall:

• A. ln front of him
• B. In his hand
• C. Behind him✓
• D. Beside him

Explanation: At the time of throwing the ball, it inherits velocity of platform at that moment . And, the horizontal velocity of the ball is constant in the air, because no acceleration in horizontal direction for ball. However, the train is accelerating in forward direction then from frame of train, the ball has horizontal component of acceleration in backward direction.

Q149. A bomber drops a bomb when it is vertically above the target. It misses the target because of the:

• A. Vertical component of the velocity of bomber
• B. Force of gravity
• C. Acceleration of the bomber
• D. Horizontal component of the velocity of bomber✓

Explanation: When a bomber drops a bomb, the bomb will follow a projectile trajectory influenced by both the vertical and horizontal components of the bomber's velocity. The force of gravity acts vertically downward and affects the vertical motion of the bomb, causing it to fall towards the ground.However, the horizontal component of the bomber's velocity determines the horizontal distance the bomb will travel before hitting the ground. If the bomber's horizontal velocity is not aligned with the target, the bomb will miss the target horizontally.

Q150. The property of the moving object by virtue of which it exerts force on the object that tries to slop it is:

• A. inertia of the body✓
• B. quantity of motion in the body
• C. Acceleration of body
• D. All of these

Explanation: Inertia means resistance to change. It is the property of the body by virtue of which it cannot change by itself its state of rest or of uniform motion unless an unbalanced external force acts on it. The quantity of motion is called momentum. Momentum and acceleration do not try to stop a body; they are only used to describe motion, so only option A is correct.

Q151. The dot product of force and velocity is equal to:

• A. power✓
• B. impulse
• C. couple
• D. Momentum

Explanation: Velocity=distance/time Force x velocity can also be written as force x distance or time force x distance = work done so the formula can be written as Work done/time, which is the formula for power, Impulse = force x time Couple = force x distance Momentum = mass x velocity

Q152. The escape velocity from the earth gravitational field depends upon:earth's

• A. rotation of earth
• B. mass of body
• C. radius of earth✓
• D. mass of earth

Explanation: Escape velocity, Ve​ =√( 2GM/R) Acceleration due to gravity, g= GM/R², which is always constant. Plugging this value of g in the first equation: Ve= √2gR , where R is the radius of the earth . From the above equation, we see escape velocity is dependent upon is gravitational acceleration and radius of the earth so option C is correct.

Q153. If the velocity of a body becomes half, the kinetic energy of the body will become:

• A. one fourth✓
• B. double
• C. four times
• D. half

Explanation: Kinetic energy=1/2mv² where m is mass of body and v us it's velocity so kinetic energy is directly proportional to v² So if velocity is reduced by ½ then kinetic energy is reduced by (½)²=¼ so kinetic is reduced by one fourth.

Q154. The angular velocity for the daily rotation of the earth is

• A. π/3 radian hr-1
• B. π/6 radian hr-1
• C. π/12 radian hr-1✓
• D. 12 radian hr-1

Explanation: The angular velocity (ω) is the scalar measure of rotation rate. In one complete rotation, angular distance travelled is 2π and time is time period (T). Angular velocity is given by the following formula: ω=2π/T The time period for one complete rotation of the Earth is 24 hours so ω=2π/24 =π/12

Q155. The weight of a pilot when diving down in a jet plane with an acceleration of 9.8m/s2 will become

• A. Double
• B. Half
• C. Negative
• D. Zero✓

Explanation: Weight of pilot = Original Weight + Apparent Weight = mg+(-ma) a= 9.8ms-2 So weight of pilot = 0

Q156. The Geostationary satellites are

• A. stationary
• B. Rotating with the speed of earth✓
• C. rotating very fastly
• D. rotating very slowly

Explanation: Geostationary satellites remain at the same position with respect to the Earth, so that they scan the same place in a better way. Therefore, the relative velocity of geostationary satellite with respect to the spinning motion of the Earth is 0 m/s.

Q157. ML-1T-1 are the dimension of

• A. angular momentum
• B. power
• C. impulse
• D. viscosity✓

Explanation: The dimensions ML-1T-1 indeed correspond to viscosity. The correct explanation for option D is as follows:Viscosity is a property of fluids that measures their resistance to flow. It determines how easily a fluid can be deformed under the influence of shear stress. The dimensions ML-1T-1 represent viscosity, where:M represents massL represents lengthT represents time In the context of the dimensions ML-1T-1, viscosity is proportional to mass divided by the product of length and time. This indicates that viscosity involves the interactions between mass, length, and time in the context of fluid flow.

Q158. Two meter high tank is full of water. A hole is made in the middle of the tank. The speed of efflux is

• A. 4.9 m/s
• B. 9.8 m/s
• C. 4.42 m/s✓
• D. 3.75 m/s

Explanation: The speed of efflux is equal to the velocity gained by the fluid in falling through the distance (h1-h2) under the action of gravity. Using Bernoulli's equation

Q159. The quantity which specifies the displacement as well as the direction of motion in Simple harmonic motion is

• A. Phase angle
• B. Angular frequency
• C. Path difference
• D. Amplitude✓

Explanation: Amplitude specifies displacement and direction of SHM.

Q160. The magnitude of the periodic force, which is the simple pendulum exerts on the suspension point, depends upon

• A. length of the pendulum✓
• B. time period of vibration of pendulum
• C. mass of the bob of pendulum
• D. value of 'g'

Explanation: Periodic force depends only on the length of a simple pendulum.

Q161. When the pressure in the medium increases, the speed of sound in that medium:

• A. decreases
• B. increases
• C. does not change✓
• D. sometime decreases, some time increases

Explanation: Speed of sound does not depend on pressure of gas.

Q162. The number of loops in stationary waves depends upon:

• A. velocity of waves
• B. wavelength of waves
• C. nature of the medium
• D. frequency of waves✓

Explanation: No. of loops in stationary waves depend on frequency of waves.

Q163. When the light passes from air to glass, it suffers a change in the

• A. wavelength of light
• B. speed of light
• C. frequency of light
• D. Both A and B✓

Explanation: Both the wavelength and speed of light change when light passes from air to glass.

Q164. When the light is moving from rare medium to denser medium on reflection it suffers a phase change of:

• A. 180°✓
• B. 120°
• C. 90°
• D. 0°

Explanation: When a light wave passes from a rarer medium to a denser medium, there will be a phase change of 180°.

Q165. We can hear sound around the corner but cannot see because of:

• A. interference
• B. diffraction✓
• C. polarization
• D. dispersion

Explanation: The diffraction of sound waves around a corner is noticeable. Therefore, sound can be heard around corners but cannot be seen.

Q166. The powers of the objective and eye piece of telescope are 0.5 diopter and 10 diopter respectively. The magnifying power of telescope is:

• A. 0.5
• B. 10
• C. 20✓
• D. 0.05

Explanation: Magnifying power of telescope = focal length of objective/focal length of eyepiece = power of eyepiece/ power of objective Power of objective = 0.5 D Power of eyepiece = 10 D Magnifying Power of telescope = power of eyepiece/ power of objective = 10/0.5 = 20

Q167. At constant temperature when the volume of the given mass of gas is doubled its density becomes:doubled,temperature,At a

• A. double✓
• B. one fourth
• C. four times
• D. half

Explanation: At constant temperature, if the pressure of the gas is doubled, the density is also doubled.

Q168. The process adlabalic processthat is performed quickly is:

• A. isobaric process
• B. adlabalic process✓
• C. isothermal process
• D. isochoric process

Explanation: The adiabatic process is performed quickly when the system is perfectly insulated from the surrounding environment.

Q169. For all irreversible process, the entropy of the system:

• A. decreases
• B. remains constant
• C. is zero
• D. increase✓

Explanation: The entropy of the universe increases in an irreversible process, such as the transfer of heat from a hot object to a cold object.

Q170. The wave nature of an electron is illustrated by

• A. photoelectric effect
• B. compton effect
• C. penetrating effect
• D. diffraction✓

Explanation: The wave nature of an electron is illustrated by its electron diffraction, as explained by davisson germer experiment.

Q171. The potential gradient between two charged plates having separation of 0.5cm and a potential difference of 12 volts is:

• A. 240 NC-1
• B. 24 NC-1
• C. 2.4 NC-1
• D. 2400 NC-1✓

Explanation: As we know, Potential gradient is given by E= -dV/dR So, 12/0.005 = 2400 V/m= 2400 N/C

Q172. Ohm x Farad is equivalent to:

• A. Second✓
• B. Weber
• C. Henry
• D. Tesla

Explanation: The product of Ohm (unit of resistance) and Farad (unit of capacitance) results in the unit of time, which is the second. Therefore, option a is correct.

Q173. A wir of uniform cross section A, length I and resistance R is cut into two equal pieces. The resistivity of each piece will be

• A. the same✓
• B. one fourth
• C. double
• D. one half

Explanation: Resistivity remains constant, it is a constant value.

Q174. Two metallic conductors have the same value of resistivity These conductors can be differentiated from the values of their:

• A. Temperature coefficient✓
• B. Resistance
• C. Conductance
• D. Conductivity

Explanation: When two metallic conductors have the same value of resistivity, we can differentiate them based on their temperature coefficient. The temperature coefficient of a conductor tells us how its resistance changes with temperature. Different metals have different temperature coefficients, which means their resistance will change at different rates as the temperature changes. By comparing the temperature coefficients of the two conductors, we can determine how their resistances will vary with temperature.

Q175. The total driving force of a battery to draw current through a circuit is called:

• A. voltage of battery
• B. power of battery
• C. e.m.f of battery✓
• D. all of these

Explanation: EMF is the source of voltage in a battery responsible for flow of charges through a circuit.

Q176. Two metallic wires lying parallel, If the current in these wires is flowing in the same direction, the wires will

• A. attract each other✓
• B. repel each other
• C. have no force of attraction or repulsion
• D. remain stationary

Explanation: Parallel wires with current in the same direction exert attractive forces on eachother.

Q177. The SI unit of magnetic flux is Weber, which is equal to:

• A. NmA-1✓
• B. Nm2 A-1
• C. NAm-¹
• D. NmA-2

Explanation: The unit of magnetic flux is Weber, which is equal to J/A, which is then equal to Nm/A-1.

Q178. If an electron and a proton are projected with the same velocity normal to a magnetic field, which one will suffer greater deflection?

• A. proton
• B. electron✓
• C. both will suffer greater defection
• D. None of these

Explanation: The deflection is inversely proportional to mass, so for an electron and a proton moving with the same velocity, an electron with lighter mass will deflect more, while a proton with heavier mass will deflect less.

Q179. The motional E.M.F depends upon:

• A. Strength of magnetic field
• B. Speed of the conductor
• C. Length of conductor
• D. All answers are correct✓

Explanation: The factors on which motional emf depends are the magnetic field and velocity and length of the rod. Thus option D is the correct answer.

Q180. voltxsecond is equal to:

• A. gauss
• B. weber
• C. henry✓
• D. tesla

Explanation: Henry is the unit of inductance, which is equal to 1 volt*sec/ampere, which is the voltage across a conductor directly proportional to the rate of change of current.

Q181. The counter torque produced in the moving coil of generator is called:

• A. resotoring torque
• B. defelection torque
• C. back motor effect
• D. all of these✓

Explanation: When the current I passes through the coil, the coil experiences torque, which rotates the coil through an angle alpha. Due to deflection, suspension wire twist gives the restoring force; if the restoring force is CQ while the deflection torque is BIAN Cos alpha, then BIAN Cos alpha=CQ. Hence, all of the options represent the same counter torque produced in the generator.

Q182. The inductor has an inductance of 0.5 is connected to 50 hertz ac source, what is the inductive reactance of the inductor?

• A. 94.2
• B. 1.57
• C. 157✓
• D. 9,421

Explanation: Inductive reactance is the opposition offered by the inductor in the AC circuit to the flow of AC current. Inductive reactance= = wL = 2pifL = 2*3.14*50*0.5= = 157 ohm

Q183. In RLC series circuit when the frequency of AC source is very low, the circuit an:

• A. resistive circuit
• B. capacitive circuit✓
• C. inductive circuit
• D. resonant circuit

Explanation: At low frequencies, the series circuit is capacitive as Xc>Xl, but at higher frequencies, the series circuit is inductive as Xl>Xc. With the decrease in frequency, it becomes more capacitive, i.e., the current decreases, and it changes from inductive to capacitive.

Q184. Which of the following makes the motion of a perpetual motion machine a physical impossibility?

• A. fist law of thermodynamics
• B. second law of thermodynamics✓
• C. third law of thermodynamics
• D. None of these

Explanation: As the second law of thermodynamics states, the more energy is transformed, the more is wasted. And for a perpetual motion machine to work, it has to have the energy that was never wasted, which makes it a physical impossibility.

Q185. The process of combining low frequency signal with high frequency carries waves is called:

• A. rectification
• B. amplification
• C. modulation✓
• D. magnification

Explanation: Modulation is the process of combining low-frequency signals with high-frequency carrier waves to convert data into radio waves. While rectification is the conversion of AC current into DC current, amplification simply means.

Q186. The ratio of volumetric strain to volumetric stress called:

• A. compressibility✓
• B. young's modulus
• C. bulk's modulus
• D. shear's modulus

Explanation: Compressibility is the ratio of volumetric strain to volumetric stress. It is the inverse of bulk's modulus. Its SI unit is the pascal. Strain: A force tending to pull or stretch something to an extreme or damaging degree Stress is a quantity that describes the magnitude of the forces that cause deformation (strain).

Q187. The substance that undergoes plastic deformation until it breaks is:

• A. ductile substance✓
• B. brittle substance
• C. plastic substance
• D. all of these

Explanation: The substance which undergoes plastic deformation until it breaks is a DUCTILE SUBSTANCE. Therefore, option 'A' is correct.

Q188. The process by which the potential barrier of the deplection region can be increased or decreased is called:

• A. Amplification
• B. Biasing✓
• C. Modulation
• D. Doping

Explanation: Biasing is the application of DC voltage to set up certain operating conditions. It either increases or decreases the strength-barrier potential of the junction. A forward bias reduces the strength of the potential barrier, whereas a reverse bias strengthens the potential barrier. This corresponds to the statement of the question, and thus option B is the correct option.

Q189. The color of light emitted by light emitting diode depends upon:

• A. forward voltage
• B. reverse current
• C. forward current
• D. type of semiconductor✓

Explanation: LEDs are semiconductors that convert electrical energy into light energy. The color of the emitted light depends on the type of semiconductor material. Depending on which LEDs can be classified into three wavelengths: ultraviolet, visible, and infrared, Among the above options, options ‘A, ‘B, and C’ have nothing to do with the color of light emitted by LEDs. Therefore, they are eliminated.

Q190. The combination of AND and NOT gates is called:

• A. NAND gate✓
• B. NOR gate
• C. OR gate
• D. XOR gate

Explanation: A NAND gate is a combination of AND and NOT gates. Option ‘A’ corresponds to the statement of the question.

Q191. If the temperature of the black body doubles, the intensity of radiation from it will become:

• A. double
• B. four times
• C. six times
• D. sixteen times✓

Explanation: BLACK BODY: A blackbody is a theoretical or model body that absorbs all radiation falling on it, reflecting or transmitting none. It is a hypothetical object that is a “perfect” absorber and “perfect” emitter of radiation over all wavelengths. Stefan-Boltzmann Law: It relates the total energy emitted (E) to the absolute temperature (T). E ∝ T⁴ We know that the intensity of the radiation from a black body is directly proportional to its energy. Thus, it can be concluded that if we increase the temperature of the black body by 2 (i.e., we double it), the intensity increases by 2⁴ i.e. it increases 16 times). Thus, option ‘D’ is the correct answer.

Q192. The scattering angle for which the Compton shift in wavelength is equal to Compton wavelength is:

• A. 0=90°✓
• B. 0=0"
• C. 0=45°
• D. 0=180°

Explanation: COMPTON’S EFFECT: It is the scattering of a high-frequency photon after a collision with an electron, which results in a decrease in the wavelength of the photon. The change in wavelength is called Compton’s shift and is given by: λ′−λ=hmₒc(1−cosθ). The factor hmₒc is known as compton’s wavelength. The compton’s shift and compton’s wavelength will be equal when the factor (1−cosθ) is equal to 1. Now cos should be equal to 1, and for that, θ should be 90°. Thus, option ‘A’ is the right answer.

Q193. The uncertainty in energy of a photon that is emitted from an atom radiating for 10 seconds is:

• A. 4x10 joul
• B. 4x107 ev✓
• C. 6.6x10 ev
• D. 4x10 joul

Explanation: HEISENBERG’S UNCERTAINTY PRINCIPLE : The uncertainty in the energy (ΔE) times the uncertainty in the time (Δt) is greater or equal to planck’s constant (h). i.e ΔE . Δt = h h ΔE = --- Δt (placing values) 6.62 × 10⁻³⁴ ΔE = ----------------- 1 × 10⁻⁸ ΔE = 6.62 × 10⁻²⁶ Joules 6.62 × 10⁻²⁶ ΔE = ------------------ 1.6 × 10⁻¹⁹ ΔE = 4 × 10 ⁻⁷ eV

Q194. When the voltage of the target in the X-ray tube increases, then the

• A. penetrating power of x-ray increases
• B. intensity of x-rays increases✓
• C. wavelength of x-rays increases
• D. all of these

Explanation: X-RAY TUBE: An X-ray tube is a vacuum tube that converts electrical input power into X-rays. The increase in x-ray tube voltage increases the amount of radiation coming out, i.e., the intensity of X-rays increases. Also, the average photon energy increases (i.e., the wavelength decreases).

Q195. The frequency of light having wavelength 3×10 cm is

• A. 1x10
• B. 3.0x107
• C. 1x10¹0
• D. 1x1013✓

Explanation: We know that v = f λ v --- = f λ (placing values) 3 × 10⁸ f = ------------------ 3 × 10⁻³ × 10⁻² f = 1 × 10¹³

Q196. When a radioactive atom decays and its mass number decreases by 4 and charge number decreases by 2, the atom will emit

• A. Alpha radiation✓
• B. Beta radiation
• C. Gamma radiation
• D. X radiation

Explanation: Alpha radiations are doubly positively charged helium nuclei. When such radiation is emitted from a radioactive element, its mass number decreases by 4 and its atomic number decreases by 2.

Q197. One disintegration per second is equal to

• A. one curie
• B. one Becquerel✓
• C. one half life
• D. all of these

Explanation: In radioactivity, activity is defined as disintegrations per second. The SI unit of Activity is Becquerel (Bq). Thus, 1 disintegration per second is equal to 1 Bq.

Q198. A fission reaction can be produced by:

• A. fast neutrons✓
• B. slow neutrons
• C. thermal neutrons
• D. all of these

Explanation: Fission occurs when a neutron bumps into a larger atom, forcing it to excite and split into two smaller atoms, known as fission products. Elements with odd atomic masses are more fissile (prone to fission) because the extra neutron adds the energy required to fission the resulting nucleus. U-238 has even more atomic mass. Thus, because of the large amount of energy needed, U-238 can only undergo fission when fast-moving neutrons strike it.

Q199. The correct expression for the coulomb's force is:

• A. F-1=1/4πe0 x q1q2/r2 x r
• B. F = 1/4πe0 x q1q2/r2 x r✓
• C. F-1 = 1/4πe x q1q2/r2 x r
• D. F = 1/4πe x q1q2/r2 x r

Explanation: According to the expression of coulomb’s law, the magnitude of Coulomb’s force is directly proportional to the product of two point charges and inversely proportional to the square of the distance between them.

Q200. In oogamy, fertilization involves:

• A. A small non­-motile female gamete and a large motile male gamete
• B. A large non-­motile female gamete and a small motile male gamete✓
• C. A large non-­motile female gamete and a small non-motile male gamete
• D. A large motile female gamete and a small non­-motile male gamete

Explanation: Oogamy is the sexual reproduction involving the formation and subsequent fusion of a large, usually stationary, non-motile, female gamete and a small, motile male gamete. The female gamete may contain nourishment for the development of the embryo, which is often retained and protected by the parent organism. Therefore, option B is correct.A. The female gamete is large, not small, and the male gamete is small, not large.C. The female gamete is non-motile, but the male gamete is motile.D. The female gamete is non-motile, and the male gamete is motile.