Uhs Mdcat 2011 — Solved Past Paper with Answers

Q1. She managed to _ a ticket for the cricket match.

• A. Procure✓
• B. Obscure
• C. Improvise
• D. Preclude

Explanation: Procure means to obtain (something).It is obvious that Procure will be best choice.

Q2. Things have got out of hand; we must take steps to _ the situation.

• A. Rectify✓
• B. Pacify
• C. Purify
• D. Testify

Explanation: Rectify means to correct, put right.When things go wrong we make them right thus Rectify is the correct word.

Q3. George Orwell’s Animal Farm is a stinging _ on the Russian revolution.

• A. Myth
• B. Satire✓
• C. Fallacy
• D. Legend

Explanation: As the word stinging suggests this must be something not so good for history thus the word Satire correctly follows.

Q4. All the _ and ceremony of the royal wedding were telecast on the national television circuit.

• A. Festival
• B. Romp
• C. Pomp✓
• D. Happiness

Explanation: Pomp is a celebration or festive display.From the information above it is clear that Pomp is the word best suited in the sentence given above.

Q5. Select the incorrect segment:The patient’s blood analysis shows that there is a big number of amorphous cells which are quiet unidentifiable.

• A. Patient’s
• B. Of
• C. Which
• D. Quiet✓

Explanation: The right word that should be used at this place is QUITE which means absolutely. QUEIT refers to not saying anything which is not the word required here .

Q6. Select the incorrect segment:The police, in their investigation, used coercive measure to get a favorable statement from the accused.

• A. Measure✓
• B. To
• C. From
• D. The accused

Explanation: It should be "measures" (plural), not measure (singular).

Q7. Select the incorrect segment:Your argument is simply abstruse as there is no clarity of thought and coherence in ideas and it also lack vision.

• A. Is
• B. Of
• C. In
• D. Lack✓

Explanation: The incorrect segment is: "it also lack vision."Explanation:The subject "it" is singular, so the verb should also be singular."Lack" is incorrect because it is the base form of the verb, while the correct form should be "lacks" to match the singular subject.Corrected sentence:"Your argument is simply abstruse as there is no clarity of thought and coherence in ideas, and it also lacks vision."

Q8. The workers were raising much hue and cry when their demands were turned away.

• A. Raising
• B. Much
• C. Demands
• D. Away✓

Explanation: The correct phrasal verb to be used here is 'turned down' and not turned away. It means to reject something.

Q9. The disease is uncurable without the judicious use of antibiotics.

• A. Uncurable✓
• B. Without
• C. Judicious
• D. Use

Explanation: "Uncurable" is not a word. The correct word is "Incurable".

Q10. The younger sister hopes to emulate her elder sister’s sporting achievement as she is putting up hectic effort.

• A. To
• B. Sister’s
• C. Achievement
• D. Up✓

Explanation: According to rules regarding Phrasal verbs,the correct form is 'putting in' and not 'putting out'.Putting in means make a formal offer.

Q11. Choose the correct sentence from the following options:

• A. The government should accrue taxes for strengthen the economy of the country.
• B. The government should accrue taxes in strengthen the economy of the country
• C. The government should accrue taxes to strengthen the economy of the country.✓
• D. The government should accrue taxes by strengthen the economy of the country.

Explanation: By comparing all four sentences ,you notice there is only one difference i.e. PREPOSITION and for fact the best suited is 'to strengthen'.

Q12. Choose the correct sentence from the following options:

• A. I remember going to British Museum one day.
• B. I remember to go to British Museum one day.
• C. I remember to go to the British Museum one day.
• D. I remember going to the British Museum one day.✓

Explanation: "I remember going to the British Museum one day": This sentence is the correct sentence. It is grammatically correct and idiomatic. The word "to" is used as a preposition to show the direction of movement, and the verb "go" is in the past tense to show that the speaker is remembering an event that happened in the past.

Q13. Select the NEAREST CORRECT MEANING of the given word:MUSE

• A. Wander
• B. Fonder
• C. Robust
• D. Ponder✓

Explanation: Some common synonyms of muse are meditate, ponder, and ruminate. All these words mean "to consider or examine attentively or deliberately”

Q14. Select the NEAREST CORRECT MEANING of the given word:FECKLESS

• A. Useless
• B. Careless✓
• C. Dauntless
• D. Fearless

Explanation: Feckless means to be irresponsible, lacking initiative or strength of character.

Q15. Select the NEAREST CORRECT MEANING of the given word:MOSAIC

• A. Pattern✓
• B. Mortal
• C. Ordinary
• D. Musical

Explanation: A mosaic is a pattern or image made of small pieces.

Q16. Select the NEAREST CORRECT MEANING of the given word:INSCRUTABLE

• A. Immoral
• B. Unethical
• C. Enigmatic✓
• D. Unaccountable

Explanation: Inscrutable means impossible to understand or interpret, blank.

Q17. Select the NEAREST CORRECT MEANING of the given word:JUXTAPOSE

• A. Justify
• B. Compare✓
• C. Expose
• D. Jettison

Explanation: Juxtapose means to compare or contrast.

Q18. Select the NEAREST CORRECT MEANING of the given word:LACERATING

• A. Landing
• B. Tearing✓
• C. Flagging
• D. Lactating

Explanation: Lacerating means to make deep cuts.

Q19. Select the NEAREST CORRECT MEANING of the given word:EMPATHY

• A. Fictitious
• B. Facility
• C. Ability✓
• D. Felicity

Explanation: Fictitious means not real or true; imaginary or fabricated. A facility is a place or amenity built for a specific purpose. Ability means the talent or skill to do something. Felicity is intense happiness.Empathy is the ability to understand and share the feelings of another. Therefore, "ability" is the closest choice.

Q20. Select the NEAREST CORRECT MEANING of the given word:EVANESCENT

• A. Evident
• B. Permanent
• C. Event
• D. Transitory✓

Explanation: Evanescent means fading or short-lived.

Q21. Select the NEAREST CORRECT MEANING of the given word: SIDLE

• A. Sneak✓
• B. Sift
• C. Siege
• D. Sieve

Explanation: To sidle means to walk in a furtive, unobtrusive, or timid manner, especially sideways or obliquely.

Q22. Select the NEAREST CORRECT MEANING of the given word:DISSONANCE

• A. Inconsistency✓
• B. Expansion
• C. Perceptible
• D. Rapport

Explanation: Dissonance means lack of harmony or agreement.

Q23. An association between two organisms benefiting both is called:

• A. Commensalism
• B. Parasitism
• C. Predation
• D. Symbiosis✓

Explanation: Option A is incorrect because Commensalism is relationship in which one organism is benefited other is neither benefited nor harm.Option B is incorrect because Parasitism is relationship in which a parasite live with host body get food and shelter and in return cause disease.Option C is incorrect because Predation is a relationship in which an animal feed on other animal and the animal feed is predator and animal that is caught and eaten is prey.Option D is correct since An association between two beneficial organisms is called symbiosis.

Q24. In aquatic ecosystem, human activities may accelerate the process of:

• A. Eutrophication✓
• B. Photosynthesis
• C. Decomposition
• D. Recycling

Explanation: Option A is correct since Eutrophication is the process in which the water body has an enriched amount of nutrients and thus more life and decaying bodies which cause smell. And this process is enhanced by human activities like use of washing powders and fertilizers.Option B is incorrect because Photosynthesis is the process by which plants prepare their food by using sunlight and this process cannot be accelerated by human activities.Option C is incorrect because Decomposition is process of decaying dead matter and done by bacteria human activities have no role.Option D is incorrect because Recycling is process by which old things are reused.

Q25. Beri Beri is due to:

• A. Metabolic disorder
• B. Chemical causes
• C. Nutritional deficiency✓
• D. Mental Illness

Explanation: Option A is incorrect since a metabolic disorder occurs when the metabolism process fails whereas beri beri is caused by deficiency of vitamin B1.Option B is incorrect since chemical diseases happens due to diseases, injuries, aging, chronic stress and poor nutrition whereas beri beri is caused by deficiency of vitamin B1.Option C is correct since Beri beri is nutritional disorder caused by deficiency of Vitamin B1.Option D is incorrect since mental illness are disorders that affect your mood, thinking and behavior whereas beri beri is caused by deficiency of vitamin B1.

Q26. The natural heat energy trapped underground is:

• A. Geothermal energy✓
• B. Thermal energy
• C. Electric energy
• D. Solar energy

Explanation: Option A is correct since Geothermal energy is natural heat trapped underground.Option B is incorrect because Thermal energy is only heat energy.Option C is incorrect because Electric energy is due to potential difference between two points.Option D is incorrect because Solar energy is energy of sunlight.

Q27. Which of the following is the lowest level of biological organization with respect to others?

• A. Multicellular organisms✓
• B. Biosphere
• C. Species
• D. Population

Explanation: Option A is correct since Multicellular organism level is the lowest that consist only one organism.Option B is incorrect because Biosphere is the thin layer of earth where all types of life exist, it is highest level.Option C is incorrect because Specie is very similar , potentially interbreeding organisms it is next to organism level.Option D is incorrect because Population is members of one species inhibiting the same area and it is next to specie level.

Q28. When an electron pair is shared between two atoms:

• A. Two covalent bonds are formed
• B. Hydrogen bond is formed
• C. Single covalent bond is formed✓
• D. Ionic bond is formed

Explanation: Option A is incorrect because Two covalent bonds are formed by the sharing of two electron pairs.Option B is incorrect because Hydrogen bond is the weak interaction between partially positive hydrogen atom and partially negative atom, mainly oxygen.Option C is correct since A single covalent bond is formed by the sharing of one electron pair means 2 electrons.Option D is incorrect because Ionic bond is formed by the electrostatic interaction of two oppositely charged ions.

Q29. The first microbe to have the genome completely sequenced which was published on July 28th, 1995 was:

• A. Hyphomicrobium
• B. Haemophilus aquaticus
• C. Haemophillus malariae
• D. Haemophillus infulenzae✓

Explanation: H. influenzae was the first free-living organism to have its entire genome sequenced.

Q30. An activated enzyme consisting of polypeptide and a cofactor is known as:

• A. Amylase
• B. Apoenzyme
• C. Holoenzyme✓
• D. Coenzyme

Explanation: Option A is incorrect because Amylase is the enzyme that breakdown carbohydrates.Option B is incorrect because Apoenzyme is the enzyme with its cofactor removed it is non functional.Option C is correct since Holoenzyme is an activated enzyme consisting of polypeptide and a cofactor.Option D is incorrect because Coenzyme is a type of cofactor that loosely attached to the protein part.

Q31. _ forms weak linkages with enzymes and their effect can be neutralized completely or partly by an increase in the concentration of the substrate.

• A. Only competitive Inhibitors
• B. Reversible inhibitors✓
• C. Irreversible inhibitors
• D. Both reversible and irreversible inhibitors

Explanation: The explanation is as follows: (PTB, Chapter 3)

Q32. In prokaryotic cell wall, strengthening material is:

• A. Cellulose
• B. Silica
• C. Chitin
• D. Peptidoglycan✓

Explanation: Peptidoglycan is a complex polymer made of sugars and amino acids that forms a rigid layer around prokaryotic cells. It provides strength, maintains shape, and protects the cell from bursting due to osmotic pressure.

Q33. The entire cell wall of bacteria is often regarded as a single huge molecule or molecular complex called_:

• A. Capsule
• B. Secondary wall
• C. Slime capsule
• D. Sacculus✓

Explanation: The sacculus is the rigid layer that forms the outermost part of the cell wall in bacteria. It is made up of peptidoglycan, a polymer of sugars and amino acids. The sacculus is responsible for providing the cell with shape and strength. It also helps to protect the cell from the environment and from attack by the host immune system.

Q34. Krebs cycle takes place in:

• A. Dictyosomes
• B. Mitochondrial matrix✓
• C. Lysosomes
• D. Vesicles of endoplasmic reticulum

Explanation: The Krebs cycle takes place in the mitochondrial matrix, which is the innermost compartment of the mitochondria. It is the site where various reactions of the Krebs cycle occur, leading to the complete oxidation of acetyl-CoA derived from glycolysis.

Q35. Chemically, viruses are made up of

• A. Nucleic acid only
• B. Protein only
• C. Nucleic acid and protein✓
• D. Lipoproteins

Explanation: The correct answer is option C, which states that viruses are made up of both nucleic acid and protein. This dual composition is crucial for their functionality. The nucleic acid, which can be either DNA or RNA, houses the genetic information necessary for the virus to replicate and infect host cells. The protein components, primarily the capsid, protect the nucleic acid and facilitate the virus's interaction with host cells.Options A and B are incorrect as they only consider one component of viral structure, neglecting the essential presence of the other. Option D is misleading because while some viruses do have a lipid envelope, it is not a characteristic applicable to all viruses, making nucleic acid and protein the fundamental components.

Q36. Widespread epidemic disease, influenza is caused by:

• A. DNA virus
• B. RNA enveloped virus✓
• C. DNA enveloped virus
• D. RNA virus

Explanation: Influenza is caused by an enveloped RNA virus.

Q37. When the division of cells is in three planes, the arrangement is known as:

• A. Diplococcus
• B. Sarcina✓
• C. Streptococcus
• D. Staphylococcus

Explanation: Option A is incorrect because Division in one plane that form a pair of coocci is called diplococcus.Option B is correct since Division in three planes produces an arrangement called sarcina that is a cube of 8 cocci.Option C is incorrect because Streptococcus is division in one plane and has more than 2 cocci.Option D is incorrect because Staphylococcus is arrangement in which cocci are arranged in irregular , often grape like cluster.

Q38. Bacterial ‘death rate’ is equal to ‘birth rate; in:

• A. Lag phase
• B. Log phase
• C. Death phase
• D. Stationary phase✓

Explanation: Option A is incorrect because Lag phase is phase of no growth and bacteria prepare themselves for division.Option B is incorrect because Log phase is the phase of rapid growth, bacteria divide at exponential rate.Option C is incorrect because Death phase is phase in which bacteria start dying, and death rate is more than reproduction rate.Option D is correct since At stationary phase bacterial death rate is equal to reproduction rate.

Q39. Trypanosoma is a human parasite causing:

• A. African sleeping sickness✓
• B. European sleeping sickness
• C. Indonesian sleeping sickness
• D. American sleeping sickness

Explanation: Parasitic flagellates cause diseases. For example Trypanosoma is a human parasite causing African sleeping sickness. It is transmitted by the bite of infected tsetse fly.

Q40. The feeding stage of slime mold is a:

• A. Gastrozoid
• B. Sporozoite
• C. Plasmodium✓
• D. Merozote

Explanation: Usually, plasmodial slime molds exist as a plasmodium. It is a diploid multinucleated cytoplasmic mass enveloped by a slime sheath. At times unfavorable to growth, such as during drought the Plasmodium develops many sporangia

Q41. Drug obtained from fungus used for lowing blood cholesterol is:

• A. Lovastatin✓
• B. Cyclosporin
• C. Ergotin
• D. Griseofulvin

Explanation: Option A is correct since Lovastatin is obtained from fungus and used for lowering blood cholesterol level. Option B is incorrect because Cyclosporin is used to prevent transplantation rejection and it is obtained from soil fungus. Option C is incorrect because Ergotin is used to relieve one kind of headache migraine. Option D is incorrect because Griseofulvin is used to inhibit fungal growth.

Q42. Fungi store surplus food in the form of:

• A. Cellulose
• B. Glycogen✓
• C. Starch
• D. Both B and C

Explanation: Option A is incorrect because Fungi do not store food in form of cellulose.Option B is correct since Fungi store surplus food usually as lipid droplet or glycogen form.Option C is incorrect because Fungi do not store food in form of starch .Plants store food in form of starch.Option D is incorrect because Fungi do not store food in form of starch.

Q43. The ecological role of fungi as decomposers is paralleled only by:

• A. Prions
• B. Algae
• C. Bacteria✓
• D. Viruses

Explanation: Option A is incorrect because Prions are infectious proteins that cause infection in humans and cows. Option B is incorrect Algae have no role in decomposition. Option C is correct because The ecological role of fungi as decomposers is paralleled only by bacteria.Option D is incorrect because Viruses have no role in decomposition.

Q44. “Vascular System absent"; gametophyte dominant, sporophyte attached to gametophyte; "homosporous” are distinguishing characters of:

• A. Psilopsida
• B. Pteropsida
• C. Angiosperms
• D. Bryophyta✓

Explanation: The distinguishing characters "Vascular System absent; gametophyte dominant, sporophyte attached to gametophyte; homosporous," are indicative of the bryophyte group known as liverworts (Hepatophyta). Liverworts are non-vascular plants, meaning they lack a true vascular system for the transport of water and nutrients. Instead, they rely on diffusion for these processes. The sporophyte generation is physically attached to the gametophyte. The sporophyte typically consists of a capsule (containing spores) and a seta (stalk) and remains dependent on the gametophyte for nutrients and support.

Q45. Which of the following features differentiate angiosperms from gymnosperms?

• A. Pollens disperse by air
• B. Haploid microspores
• C. Ovaries✓
• D. Pollen tubes

Explanation: Angiosperms have ovaries, which are structures that enclose and protect the seeds. Ovaries are part of the flower and develop into fruits after fertilization. Gymnosperms lack true ovaries. Instead, the seeds are exposed on the surface of cone scales. Gymnosperms include conifers, cycads, ginkgos, and gnetophytes.

Q46. In Pakistan, the furniture wood is mainly obtained from the members of family:

• A. Rosaceae
• B. Solanaceae
• C. Minosaceae
• D. Fabaceae✓

Explanation: The Fabaceae family, commonly known as the legume or pea family, includes a diverse group of plants, many of which have economic importance as sources of timber. Timber-producing species within the Fabaceae family are often valued for their hardwood, which is used in construction, furniture making, and various other applications.

Q47. Which of the following is the exclusive character of mammals?

• A. Homeothermic
• B. Poikilothermic
• C. Hair✓
• D. Four chambered heart

Explanation: Hair is a defining characteristic of mammals. Most mammals have hair or fur covering some or all of their bodies. This feature distinguishes them from other animal groups.

Q48. Overactivity of the sympathetic nervous system causes:

• A. Disturbance of Vision
• B. Constipation
• C. Decrease in Blood Pressure
• D. Increase in Heart Rate✓

Explanation: The sympathetic nervous system responds to dangerous/stressful situations by pumping blood at a faster rate to the muscles.

Q49. Which structures respond when they are stimulated by an impulse coming through the motor neuron?

• A. Receptors
• B. Responses
• C. Effectors✓
• D. Transduction

Explanation: After a stimulus is received, the central nervous system responds by sending a response via a motor neuron, which transports the signal to the effector, which carries out the action.

Q50. Respiratory centre is located in:

• A. Cerebrum
• B. Cerebellum
• C. Medulla✓
• D. Hypothalamus

Explanation: The medulla is responsible for, among other things, the controlling of involuntary activities, such as heartbeat, respiration, etc.

Q51. A neurological condition characterised by involuntary tremors, diminished motor activity, and rigidity is called:

• A. Epilepsy
• B. Parkinson’s Disease✓
• C. Alzheimer’s Disease
• D. Cerebellar Tumours

Explanation: Parkinson’s Disease is characterized by shaking, stiffness, and lack of balance and coordination, all of which fulfill the requirements of the question.

Q52. A type of cell in human testes which produces testosterone is called:

• A. Interstitial Cells✓
• B. Germ Cells
• C. Sertoli Cells
• D. Spermatocytes

Explanation: In the testes, interstitial cells are present in the connective tissue surrounding the sperm producing tubules, and are respnsible for the production and secretion of testosterone.

Q53. Breakdown of the endometrium during menstruation is due to:

• A. Increase in the level of LH
• B. Decrease in the level of progesterone✓
• C. Increase in the level of FSH
• D. Increase in the level of estrogen

Explanation: If fertilization doesn't occur, the corpus luteum starts to degenerate, leading to a decrease in progesterone production. This decrease in progesterone levels triggers a breakdown of the endometrial lining. Without the support of progesterone, the blood vessels in the endometrium constrict, leading to reduced blood flow to the tissue. This causes the superficial layers of the endometrial lining to slough off, resulting in menstruation. So option B is correct.

Q54. Oogonia are produced in the germ cells of:

• A. Both Uterus and Cervix
• B. Cervix
• C. Uterus
• D. Ovary✓

Explanation: Oogonia are produced by primordial germ cells during fetal development, in large numbers in the ovary.

Q55. Which of the following diseases can be prevented through vaccination?

• A. AIDS and Cancer
• B. Malaria and AIDS
• C. Typhoid and Cancer
• D. Measles and Mumps✓

Explanation: Measles and mumps, both can be prevented by a joint two-dose vaccine, i.e. the MMR vaccine.

Q56. Newly produced cells/individuals which are identical in each other are known as:

• A. Genetically Modified
• B. Transgenic Animals
• C. Transgenic Bacteria
• D. Clones✓

Explanation: Cells/individuals which are genetically identical to each other are called clones.

Q57. Which of the following is a blood borne disease?

• A. Hepatitis✓
• B. Cholera
• C. Influenza
• D. Candidiasis

Explanation: Hepatitis B and Hepatitis C are blood borne diseases, which can be transferred to other individuals by blood contact.

Q58. The control of pests has traditionally meant regulation by natural enemies, predators, parasites and pathogens. This type of control is known as:

• A. Cultural Control
• B. Biological Control✓
• C. Pesticides Control
• D. Insecticides Control

Explanation: Control of pests by means of introducing natural predators or diseases affecting the pests comes under the umbrella of biological control.

Q59. Which of the following organelles is concerned with the cell secretion?

• A. Ribosomes
• B. Golgi Apparatus✓
• C. Lysosomes
• D. Mitochondria

Explanation: The golgi body is responsible for cell secretion and acts by sorting and separating substances into different vesicles.

Q60. Which of the following contains peptidoglycan cell wall?

• A. Penicillium
• B. Bacterium✓
• C. Adiantum
• D. Polytrichum

Explanation: Bacteria have cell walls that contain peptidoglycan, a unique structural molecule that distinguishes them from fungi, plants and other organisms.

Q61. The inner membrane of mitochondria is folded to form finger like structure called:

• A. Cristae✓
• B. Vesicle
• C. Matrix
• D. Cisternae

Explanation: The cristae in mitochondria help to maximize the speed of ATP synthesis, and the more cristae present, the faster the ATP production.

Q62. Interior of chloroplast is divided into the heterogeneous structure, embedded in the stroma known as:

• A. Grana✓
• B. Thylakoids
• C. Stroma
• D. Cisternae

Explanation: The correct answer is Grana. Grana are integral structures within chloroplasts, consisting of stacks of thylakoids where the light-dependent reactions occur. These are embedded in the stroma, the fluid matrix that supports the chloroplast's functions. Thylakoids are the individual units that compose grana but are not the matrix. Stroma is indeed the matrix but not the heterogeneous structure described in the question. Cisternae belong to the Golgi apparatus, thus unrelated to chloroplast structure and function.

Q63. In which phase of the cell division is the metabolic activity of the nucleus is high?

• A. Mitosis
• B. Interphase✓
• C. Meiosis
• D. Cell Cycle

Explanation: The period of life cycle of cell (cell cycle) between two consecutive divisions is termed as the interphase or misleadingly called resting phase. It is the period of great biochemical activity and can further be divided into G1-phase, S-phase and G2-phase. G1 (Gap 1) is the period of extensive metabolic activity, in which cell normally grows in size, specific enzymes, are synthesized and DNA base units are accumulated for the DNA synthesis.

Q64. Luteinizing hormone triggers:

• A. Cessation of oogenesis
• B. Breakdown of oocytes
• C. Ovulation✓
• D. Development of zygote

Explanation: Luteinizing hormone (LH) is a hormone produced by the anterior pituitary gland. It plays a crucial role in the female reproductive system by triggering ovulation. Ovulation is the process in which a mature follicle in the ovary releases an egg (oocyte) into the fallopian tube, where it can potentially be fertilized by sperm. Hence, option C is correct.

Q65. Syphilis is a sexually transmitted disease which is caused by:

• A. HIV / AIDS
• B. Pseudomonas Pyogenes
• C. Treponema Pallidum✓
• D. Neisseria

Explanation: The bacteria responsible for causing syphilis is treponema pallidum.

Q66. Muscle is made up of many cells, which are referred to as:

• A. Myofilaments
• B. Myofibrils
• C. Sarcolemma
• D. Muscle Fibers✓

Explanation: Muscle fibers are long cells that combine to coordinate the movement of different parts of the body.

Q67. The length of myofibril from one Z-band to the next is known as:

• A. Sarcomere✓
• B. Sarcolemma
• C. Sarcoplasm
• D. Muscle Fiber

Explanation: Sarcomeres are the basic unit of muscle tissue and are present between two Z-lines in a muscle.

Q68. The Ca++ ions released during a muscle fiber contraction attach with:

• A. Myosin
• B. Actin
• C. Troponin✓
• D. Tropomyosin

Explanation: During muscle contraction, Ca++ ions are released from the sarcoplasmic reticulum and bind specifically to troponin, a regulatory protein attached to the actin filaments. This binding causes a conformational change in troponin that moves tropomyosin, another protein, away from the myosin-binding sites on actin. This exposure allows the myosin heads to attach to actin, initiating muscle contraction. Myosin and actin are crucial for the contraction process, but they do not directly bind with calcium ions. Tropomyosin is involved in the regulation process, but does not interact directly with calcium ions either.

Q69. A muscle condition resulting from the accumulation of lactic acid and ionic imbalance is:

• A. Tetany
• B. Muscle Fatigue✓
• C. Cramp
• D. Tetanus

Explanation: As the muscles keep working constantly, they run out of oxygen, which leads to them respiring anaerobically, which in turn causes lactic acid buildup, thus causing the muscles to fatigue.

Q70. The pigment which stores oxygen in muscles is:

• A. Hemoglobin
• B. Myoglobin✓
• C. Myosin
• D. Actinomyosin

Explanation: Myoglobin is a protein present in muscles, which has one oxygen-binding site, and its function is to supply muscles constantly with oxygen.

Q71. Neurosecretory cells are present in which part of brain:

• A. Hypothalamus✓
• B. Midbrain
• C. Pons
• D. Cerebellum

Explanation: Neurosecretory muscles are present in the hypothalamus of the brain, where they function to produce hormones like ADH, which are then stored in the pituitary gland.

Q72. Which of the following is the function of glucagon hormone?

• A. Glycogen to Glucose✓
• B. Glucose to Glycogen
• C. Glucose to Lipids
• D. Glucose to Proteins

Explanation: Glucagon is a hormone released by the pancreas, which helps maintain blood sugar levels. It does this by converting glycogen into glucose, thus increasing blood sugar.

Q73. Addison’s disease is caused due to destruction of:

• A. Adrenal Cortex✓
• B. Pituitary Adrenal Axis
• C. Adrenal Medulla
• D. Hypothalamus

Explanation: Addison’s Disease emerges as a result of destruction of the adrenal cortex, which leads to metabolic disturbances such as weakened muscle action and loss of salt. Stresses that would normally be overcome (e.g., cold) lead to collapse and death.

Q74. Which group of hormones is made up of amino acids and their derivatives?

• A. Vasopressin and ADH
• B. Epinephrine and Norepinephrine✓
• C. Estrogen and Testosterone
• D. Insulin and Glucagon

Explanation: Epinephrine and norepinephrine are both amino acid-derived hormones and thus are relatively small, as compared to peptide hormones, which are proteins.

Q75. The thymus gland is involved in the maturation of:

• A. Platelets
• B. B-Lymphocytes
• C. Eosinophils
• D. T-Lymphocytes✓

Explanation: The thymus gland is involved in the maturation of T cells, a type of white blood cell that plays a vital role in the immune system. T cells are responsible for cell-mediated immunity, which is a type of adaptive immunity that helps the body fight off infection.

Q76. In passive immunity which of the following component are injected into blood?

• A. Antigens
• B. Immunogens
• C. Serum
• D. Immunoglobulins✓

Explanation: Immunoglobulins provide passive immunity as the body does not have to produce antibodies; instead, the injected antibodies offer a few months of protection.

Q77. Mucous membranes are part of body defense system and they offer:

• A. Physical Barriers✓
• B. Mechanical Barriers
• C. Chemical Barriers
• D. Biological Barriers

Explanation: Mucous membranes act as physical barriers by trapping pathogens and preventing them from entering the body.

Q78. Immediate protection is obtained from:

• A. Passive Immunity✓
• B. Active Immunity
• C. Vaccination
• D. Natural Activity Immunity

Explanation: Passive immunity can be obtained immediately by injecting antitoxins, as in the case of tetanus. Unlike active immunity, which takes time to put into action.

Q79. The immunity in which T-cells recognize the antigens or micro-organisms is known as;

• A. Tissue Grafting
• B. Phagocytosis
• C. Cell Mediated Immunity / Response✓
• D. Hormonal Immunity / Response

Explanation: In cell-mediated immunity, antibodies are not involved; rather, T-cells or macrophages recognize the antigen and destroy it.

Q80. Oxidative phosphorylation, the synthesis of ATP in the presence of O₂, occurs in:

• A. Mitochondrial inner membrane✓
• B. Cytoplasm
• C. Outer membrane of mitochondria
• D. Stroma of the chloroplast

Explanation: Oxidative phosphorylation, which is the process of synthesizing ATP using oxygen, takes place on the inner membrane of mitochondria. This membrane houses the electron transport chain and ATP synthase, which together produce most of the cell’s ATP. The other options are incorrect because the cytoplasm carries out glycolysis (not oxidative phosphorylation), the outer mitochondrial membrane serves only as a protective barrier, and the chloroplast stroma is involved in photosynthetic reactions, not in oxygen-dependent ATP production. Thus, the correct site of oxidative phosphorylation is the mitochondrial inner membrane.

Q81. Glycolysis is the breakdown of glucose into two molecules of:

• A. Glycerate
• B. Lactic Acid
• C. Pyruvate✓
• D. Succinic Acid

Explanation: Glycolysis is the breakdown of glucose into two molecules of pyruvate. During glycolysis, which takes place in the cytoplasm of the cell, one molecule of glucose (a six-carbon sugar) is enzymatically transformed into two molecules of pyruvate (each containing three carbon atoms). This process involves a series of enzyme-catalyzed reactions and results in the production of a small amount of ATP and NADH, which are then used in subsequent stages of cellular respiration to generate more ATP.

Q82. Before entering the Krebs cycle, the pyruvate is first decarboxylated and oxidized into:

• A. Acetyl-CoA✓
• B. Oxaloacetate
• C. Lactic acid
• D. Citric acid

Explanation: Before entering the Krebs cycle, pyruvate is decarboxylated and oxidized into acetyl-CoA by the pyruvate dehydrogenase complex. This reaction releases one molecule of CO₂ and generates NADH. The acetyl-CoA formed then enters the Krebs cycle to combine with oxaloacetate, forming citric acid. Other options like oxaloacetate, lactic acid, and citric acid are related to cellular respiration but occur at different stages or under different conditions. Thus, the correct answer is Acetyl-CoA.

Q83. Some electron from the second primary acceptor may pass back to chlorophyll molecules by electron carrier system, yielding ATP. This process is called:

• A. Phosphorylation
• B. Photophosphorylation
• C. Non-Cyclic Phosphorylation
• D. Cyclic Phosphorylation✓

Explanation: In cyclic photophosphorylation, electrons released from the reaction center of Photosystem I (PSI) are cycled back to the chlorophyll molecules through an electron carrier system, ultimately leading to the generation of ATP. Cyclic photophosphorylation is particularly important in certain types of photosynthetic bacteria and in the light reactions of photosynthesis in the chloroplasts of some plants. It allows the cell to generate ATP without the simultaneous production of NADPH and oxygen.

Q84. Z-scheme is used for:

• A. Non-Cyclic Photophosphorylation✓
• B. Cyclic Photophosphorylation
• C. Both Cyclic and Non-Cyclic Photophosphorylation
• D. Oxidative Phosphorylation

Explanation: The Z-scheme is a concept in photosynthesis that describes the electron flow through the photosystems during the light-dependent reactions. However, it is associated with cyclic and non-cyclic photophosphorylation.Non-cyclic photophosphorylation is the process in which light energy is used to generate both ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate) by linear electron flow. The Z-scheme illustrates the flow of electrons between two photosystems, Photosystem II (PSII) and Photosystem I (PSI), and other electron carriers in a zigzag or Z-shaped pattern.

Q85. The common vectors used in recombinant DNA technology are:

• A. Probes
• B. Palindromes
• C. Plasmids✓
• D. Prions

Explanation: Plasmids are small, circular, double-stranded DNA molecules, which are used in DNA recombinant technology by modifying the plasmid and then introducing them into cells.These are self replicating and often contains drugs resistance,heavy metal resistance genes on them.These vectors are used to produce insulin in E.coli.

Q86. The enzyme used to isolate gene from DNA is:

• A. Helicase
• B. Reverse Transcriptase
• C. Restriction Enzyme✓
• D. DNA Polymerase

Explanation: Restriction enzymes are used to separate DNA molecules at specific points, and can be used to separate specific genes.So far 400 such enzymes have been identified of which 20 are used frequently in Recombinant DNA technology

Q87. Which one of the following enzymes is temperature insensitive?

• A. DNA Polymerase I
• B. Taq Polymerase✓
• C. DNA Polymerase III
• D. RNA Polymerase

Explanation: Taq polymerase is an enzyme used in DNA synthesis and proves to be most active at 70 to 80 degree Celsius, and can function even near 100 degree celsius.It is obtained from an archaeobacteria Thermus Aquaticus which is found in hot springs.Taq polymerase has its application in PCR.

Q88. When chromosomes uncoil, the nucleoli are reformed and two nuclei are the two poles of the cell; stage is known as:

• A. Prophase
• B. Metaphase
• C. Telophase✓
• D. Anaphase

Explanation: Telophase is the fifth and final phase of mitosis, the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. Telophase begins once the replicated, paired chromosomes have been separated and pulled to opposite sides, or poles, of the cell.The nucleolus reappears during telophase as part of the reversal of prophase events; it reforms from the remnants of the previous nucleolus and other membrane vesicles that are reassembling into a new nuclear envelope around the separated daughter chromosomes. This process re-forms two new nuclei, each with its own decondensed chromosomes, nuclear membrane, and nucleolus, preparing the cell for interphase.

Q89. Mental retardation, short stature, broad face and squint eyes are the symptoms of:

• A. Down’s syndrome✓
• B. Klinefelter’s syndrome
• C. Turner’s syndrome
• D. XYZ syndrome

Explanation: In Down's syndrome, there are three copies, either complete or partial, of chromosome 21. The characteristics of Down's syndrome include low muscle tone, short stature, a flat nasal bridge, and a protruding tongue. People with Down syndrome have a higher risk of some conditions, including Alzheimer's disease and epilepsy.

Q90. Chiasmata formation takes place during the process which is known as:

• A. Crossing Over✓
• B. Attachment
• C. Pairing
• D. Leptotene

Explanation: The chiasma is a structure that forms between a pair of homologous chromosomes by crossover recombination and physically links the homologous chromosomes during meiosis.Chiasmata are X-shaped structures that physically link homologous chromosomes together during meiosis I, forming at the precise sites where genetic recombination (crossing over) has occurred between non-sister chromatids. This complex process begins with programmed DNA breaks and the formation of a synaptonemal complex between homologous chromosomes, followed by the exchange of genetic material in the pachytene stage of prophase I. Chiasmata become visible during the subsequent diplotene stage and hold the chromosomes paired until they separate during anaphase I, contributing to genetic diversity and ensuring proper chromosome segregation.

Q91. Healing of a wound and repair is the phenomenon which takes place by the process of:

• A. Mitosis✓
• B. Meiosis
• C. Cell Growth
• D. Mitosis & Meiosis

Explanation: Mitosis is important for three main reasons: development and growth, cell replacement, and asexual reproduction.Mitosis heals wounds by producing new, identical cells through cell division to replace damaged or lost cells, a process called epithelization in the skin. After an injury, the body triggers mitosis, causing cells in the epidermis (outer skin layer) to divide and multiply, migrating to cover the injured area. This increases the cell count, fills in the gaps left by destroyed cells, and reconstructs the damaged tissue, leading to complete or partial repair of the wound.

Q92. Which one of the following is the main cause of cancer?

• A. Mutation✓
• B. Controlled cell division
• C. Regulated mitosis
• D. Haploid division

Explanation: Cancer is caused by changes (mutations) to the DNA within cells. The DNA inside a cell is packaged into a large number of individual genes, each of which contains a set of instructions telling the cell what functions to perform, as well as how to grow and divide.Cancer arises from genetic mutations that disrupt a cell's normal growth and division, leading to uncontrolled proliferation and potential spread. These mutations can occur in proto-oncogenes, turning them into oncogenes that drive growth, or in tumor suppressor genes that lose their ability to slow or stop cell growth. DNA repair genes can also be affected, preventing the correction of other mutations, which accumulate over time.

Q93. The covalent bond formed between two monosaccharides is called:

• A. Glycosidic Bond✓
• B. Hydrogen Bond
• C. Peptide Bond
• D. Disulphide

Explanation: A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group.

Q94. The bond formed between glucose and fructose form sucrose is:

• A. 1,4 Glycosidic Linkage
• B. 1,2 Glycosidic Linkage✓
• C. 1,6 Glycosidic Linkage
• D. 1,3 Glycosidic Linkage

Explanation: In a sucrose molecule, the 1 carbon of glucose is connected to the 2 carbon of fructose, so this bond is called a 1,2 glycosidic linkage.

Q95. In an amino acid in which the R-group is H, its name will be:

• A. Alanine
• B. Glycine✓
• C. Leucine
• D. Valine

Explanation: The simplest of the amino acids, glycine, has just a hydrogen atom in the position of the R-group.

Q96. Fatty acid are the organic compounds containing hydrogen, oxygen and one of the following are:

• A. –COOH✓
• B. –NH2
• C. Acyl
• D. Sucrose

Explanation: A fatty acid consists of a straight chain of an even number of carbon atoms, with hydrogen atoms along the length of the chain and at one end of the chain and a carboxyl group (―COOH) at the other end. It is that carboxyl group that makes it an acid (carboxylic acid).

Q97. Liposomes are used in gene therapy against:

• A. Hypercholesterolemia
• B. Coronary Artery Angioplasty
• C. Cystic Fibrosis✓
• D. Severe Combined Immunodeficiency Syndrome (SCID)

Explanation: Gene therapy using liposomes is used to treat cystic fibrosis. Liposomes are microscopic vesicles of lipoproteins, used to deliver the normal gene into the patient's cells.In a patient of Cystic Fibrosis,the mucus produced is generally thick.Cystic fibrosis patients lack a gene that codes for the transmembrane carriers of the chloride ion. Patients often die due to numerous infections of the respiratory tract.An in vivo method of treatment is being tried. Liposomes-microscopic vesicles that spontaneously form when lipoproteins are put into a solution have been coated with the gene needed to cure cystic fibrosis

Q98. Genetically engineered cells are introduced into bone marrow cells in the treatment of:

• A. Hypercholesterolemia
• B. Severe Combined Immunodeficiency Syndrome (SCID)✓
• C. Cystic Fibrosis
• D. Coronary Artery Angioplasty

Explanation: Gene therapy for SCID involves the removal of bone marrow stem cells from the patient. These cells are injected with the with a retrovirus which carries the normal gene into the cells. The stem cells are returned to the patient, and they start producing the needed enzyme.It is an example of ex-vivo gene therapy.

Q99. Which one of the following is depleting and causing thinning of ozone?

• A. Chlorine
• B. Bromine
• C. Chlorofluorocarbon✓
• D. Carbon

Explanation: Thinning in the ozone layer is caused by increasing concentrations of ozone-depleting chemicals – chlorofluorocarbons or CFCs (compounds with chlorine and/or fluorine attached to carbon) and to a lesser extent halons (similar compounds with bromine or iodine).

Q100. The typical environment of a particular organism population community is called:

• A. Niche
• B. Ecosystem
• C. Habitat✓
• D. Biosphere

Explanation: A habitat is a place where an organism makes its home. A habitat meets all the environmental conditions an organism needs to survive.

Q101. Excessive enrichment of water with nutrients by human activity by which large amount of living organic matter grows is called:

• A. Archeotrophication
• B. Eutrophication✓
• C. Enrichment
• D. Low Trophication

Explanation: Eutrophication is characterized by excessive plant and algal growth due to the increased availability of one or more limiting growth factors needed for photosynthesis.

Q102. In an ecosystem, mycorrhizae is an example of:

• A. Symbiosis✓
• B. Predation
• C. Commensalism
• D. Parasitism

Explanation: Mycorrhiza is a mutualistic relationship between fungal hyphae and roots of higher plants.

Q103. Successive stages of eating and being eaten by which recycling of materials and flow of energy takes place is called:

• A. Food Chain✓
• B. Food Web
• C. Trophic Level
• D. Food Link

Explanation: A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another; the levels in the food chain are producers, primary consumers, higher-level consumers, and finally decomposers. These levels are used to describe ecosystem structure and dynamics.

Q104. The sex of individuals of the generation always depends on one of the parents who is:

• A. Heterogametic✓
• B. Homogametic
• C. Isogametic
• D. Isomorphic

Explanation: The sex of the offspring depends on the parent who is heterogametic(XY) i.e. the father. If the parents contributes X chromosome to the zygote then the child will be a girl and if Y chromosome is contributed a boy will be born.

Q105. Which of the following will be hemophilic?

• A. XHXh
• B. XHXH
• C. XhY✓
• D. XHY

Explanation: A is a carrier (heterozygous) female. The dominant H allele prevents the recessive h allele from being expressed. B is a homozygous dominant female and does not have the disease. C is a male with a recessive h allele. Since there is no corresponding allele on the Y-chromosome, he will be hemophilic. D is a male with a dominant H allele. He will not be hemophilic.

Q106. Which of the following is an example of an X-linked recessive trait in humans?

• A. Hypophospatemic Rickets
• B. Color Blindness✓
• C. Baldness
• D. Beard Growth

Explanation: The gene responsible for color blindness is located on the X chromosome. In other words, red-green color blindness is an X-linked recessive condition. If a female inherits one normal color vision gene and one mutated gene, she won't be red-green color blind, because it's a recessive trait.

Q107. Which trait in human in an example of multiple alleles?

• A. Eye Colour
• B. Skin Colour
• C. ABO-Blood Group✓
• D. Rh-Blood Group

Explanation: The human ABO blood type is a good example of multiple alleles. Humans can have red blood cells that are of type A (IA), type B (IB), or type O (i). These three different alleles can be combined in different ways following Mendel's Laws of Inheritance.

Q108. When a gene pair at one locus interacts with another gene at another locus, the interaction is called:

• A. Dominance
• B. Multiple Alleles
• C. Pleitropy
• D. Epistasis✓

Explanation: Epistasis is when a gene at one locus alters the phenotypic expression of a gene at a second locus.

Q109. The combination of a pentose sugar with a base result in a compound is known as:

• A. Nucleotide
• B. Nucleoside✓
• C. Nucleic Acid
• D. Polynucleotide

Explanation: Nucleosides are the structural subunit of nucleic acids such as DNA and RNA. A nucleoside, composed of a nucleobase, is either a pyrimidine (cytosine, thymine or uracil) or a purine (adenine or guanine), a five carbon sugar which is either ribose or deoxyribose.

Q110. An enzyme and substrate react through a special feature or site present in the enzyme:

• A. Binding site
• B. Active site✓
• C. Catalyst site
• D. Inhibition site

Explanation: The correct answer is the active site. This is the region on the enzyme where the substrate binds and is transformed into products through a reaction. The active site is specifically shaped and charged to complement the substrate, allowing the reaction to proceed efficiently. Other options, such as the binding site and inhibition site, refer to different functions or regions of the enzyme that do not directly facilitate the enzymatic reaction.

Q111. In mass spectrometer, detector or collector measures the:

• A. Masses of isotopes
• B. Percentages of isotopes
• C. Relative abundances of isotopes✓
• D. Mass numbers of isotopes

Explanation: Mass spectrometers measure the relative abundances of isotopes of an element. Mass spectrometers are analytical instruments used to measure the mass-to-charge ratio of ions. One of the key applications of mass spectrometry is determining the relative abundances of isotopes in a sample. The basic principle involves ionizing a sample, then separating and detecting ions based on their mass-to-charge ratio. Since isotopes of an element have different masses, the mass spectrometer can distinguish between them, allowing scientists to determine the relative abundance of each isotope in a given sample.

Q112. How many 'Cl' (chlorine) molecules are in two moles of chlorine?

• A. 2 × 6.02 × 10-23 molecules
• B. 35.5 × 6.02 × 1023 molecules
• C. 2 × 1023 molecules
• D. 2 × 6.02 × 1023 molecules✓

Explanation: 1 mole of any molecule has 6.02x 1023 molecules (avogadro’s constant), so 2 moles of chlorine would have 2 x 6.02 x 1023 molecules.

Q113. Melting point of water is higher than petrol, because intermolecular forces in water are:

• A. Weaker than petrol
• B. Stronger than petrol✓
• C. Same as in petrol
• D. Negligible

Explanation: Melting and boiling points depend on the intermolecular strengths of a molecule, higher the boiling and melting point stronger the intermolecular forces. Hence melting point of water is higher than petrol because water has stronger intermolecular forces than petrol.

Q114. DNA molecule is double stranded, in which two chains of DNA are twisted around each other by:

• A. Hydrogen bonds✓
• B. Vander Waal's force
• C. Covalent bonds
• D. Dative bonds

Explanation: The 2 chains of nucleotides forming the DNA molecule are connected together and twisted around by hydrogen bonds between the 2 chains.

Q115. The elements for which the value of ionisation energy is low, can:

• A. Gain electrons readily
• B. Gains electron with difficulty
• C. Lose electrons less readily
• D. Lose electrons readily✓

Explanation: Ionisation energy is the minimum energy required to remove the most loosely bound electron of an isolated neutral gaseous atom or molecule. So low ionisation energy means the element can lose electrons more readily.

Q116. The nature of cathode rays in discharge tube:

• A. Depends on the nature of gas taken in the discharge tube
• B. Depends upon the nature of cathode in discharge tube
• C. Is independent of the nature of the gas in discharge tube✓
• D. Depends upon the nature of anode in the discharge tube

Explanation: Cathode rays in the discharge tube are the electrons produced due to ionisation of gas and that emitted by cathode due to collision of positive ions and are hence independent of nature of the gas in discharge tube.

Q117. The ability of an atom in a covalent bond to attract the bonding electrons is called:

• A. Ionization energy
• B. Ionic bond energy
• C. Electronegativity✓
• D. Electron affinity

Explanation: Electronegativity is the correct answer because it describes the tendency of an atom to attract and hold onto shared electrons in a covalent bond. Ionization energy and electron affinity relate to energy changes involving electrons but do not describe this attraction in a bond. Ionic bond energy refers to ionic interactions, not covalent bonds.

Q118. The paramagnetic character of a substance is due to:

• A. Bond pairs of electrons
• B. Lone pairs of electrons
• C. Unpaired electrons in atom or molecule✓
• D. Paired electrons in valence shells of electrons

Explanation: Paramagnetism is due to the presence of unpaired electrons in the material, so most atoms with incompletely filled atomic orbitals are paramagnetic.

Q119. Lattice energy of an ionic crystal is the enthalpy of:

• A. Combustion
• B. Dissociation
• C. Dissolution
• D. Formation✓

Explanation: The lattice energy of an ionic crystal is the enthalpy of formation.In the context of ionic compounds, the lattice energy is the enthalpy change associated with the formation of one mole of the ionic compound from its constituent ions in the gaseous state. It represents the energy released when gaseous ions come together to form a solid crystal lattice.

Q120. In Standard Enthalpy of Atomization, heat of the surrounding:

• A. Remains unchanged
• B. Increases
• C. Increases than decreases
• D. Decreases✓

Explanation: The enthalpy of atomization is the enthalpy change that accompanies the total separation of all atoms in a chemical substance. It is an endothermic process since it takes in energy to ‘atomise’ hence, decreasing the heat of surrounding.

Q121. Mole fraction of any compound is the ratio of moles of all components in a:

• A. Compound
• B. Solution✓
• C. Molecule
• D. Solid

Explanation: Mole fraction is the ratio of moles of a particular component to the total number of moles of a solution.

Q122. Molarity is defined as the number of moles of any substance dissolved:

• A. Per dm3 of water✓
• B. In one gram of water
• C. Per m3 of water
• D. In 100 ml of water

Explanation: Molarity is the number of moles of any substance dissolved in 1 dm3 of water.

Q123. In an electrolytic cell, a salt bridge is used in order to:

• A. Pass the electric current
• B. Mix solution of two half-cells
• C. Prevent the flow of ions
• D. Allow movement of ions between two half-cells✓

Explanation: A salt bridge is used to connect the oxidation and reduction half-cells of a galvanic cell (voltaic cell), a type of electrochemical cell. It maintains electrical neutrality within the internal circuit, preventing the cell from rapidly running its reaction to equilibrium.The cations, positive ions, flow toward the cathode to replace the cations that are being picked up at the electrode. The anions, negative ions, flow toward the anode to balance the positive charge of the cations that are released from the electrode.

Q124. In all oxidation reactions, atoms of an element in a chemical species lose electrons and increase their:

• A. Oxidation states✓
• B. Reductions
• C. Electrode
• D. Negative charges

Explanation: Since an atom loses an electron, their oxidation state becomes more positive (increases).

Q125. In 'AgCl' solution, some salt of NaCl is added, 'AgCl' will be precipitated due to:

• A. Solubility
• B. Electrolyte
• C. Unsaturation effect
• D. Common ion effect✓

Explanation: NaCl dissolves forming Na+ and Cl- ions, Cl- act as a common ion and decreases the solubility of AgCl, hence precipitating AgCl.

Q126. ‘Ka’ for an acid is higher, the stronger is the acid; relate the strength of an acid with ‘pKa’:

• A. Higher pKa, weaker the acid
• B. Lower pKa, stronger the acid
• C. pKa has no relation with acid strength
• D. Both “Higher pKa, weaker the acid” & “Lower pKa, stronger the acid”✓

Explanation: pKa = -log Ka, higher the Ka means lower the pKa. Since higher Ka means stronger acid, then lower pKa also means stronger acid and vice versa.

Q127. It is experimentally found that a catalyst is used to:

• A. Lower the activation energy✓
• B. Increase the activation energy
• C. Lower the pH
• D. Decrease the temp of the reaction

Explanation: A catalyst reduces the activation energy of a chemical reaction by providing an alternate route.

Q128. According to collision theory of bimolecular reaction in gas phase, the minimum amount of energy required for an effective collision is known as:

• A. Heat of reaction
• B. Rate of reaction
• C. Has no effect on the reaction
• D. Energy of activation✓

Explanation: The minimum energy with which molecules must be moving in order for an effective collision to result in a chemical reaction is known as the activation energy or the energy of activation.

Q129. Carbon exists as allotropes, which are different crystalline or molecular forms of the same substance. Graphite and diamond are allotropes of carbon. Diamond is a non-conductor whereas graphite is a good conductor because:

• A. Graphite has a layered structure
• B. In graphite, all valence electrons are tetrahedrally bound
• C. In graphite one of valence electron is free to move✓
• D. Graphite is soft and greasy bound

Explanation: Graphite conducts electricity whereas diamond does not because in diamond the carbon atoms are bonded to other carbon atoms and all the valence electrons are bonded. whereas in graphite each carbon atom is only bonded to three other atoms. Therefore, there are delocalized (free) electrons in graphite due to 1 free valence electron in each carbon atom, which can move and carry a charge so graphite conducts electricity.

Q130. The diagram below is a plot of melting points of elements of second period against their atomic numbers. Lithium and fluorine are placed at the extreme ends of the plot, on the basis of melting points where will you place Carbon among the empty slots on the plot?

• A. 1
• B. 2
• C. 4
• D. 3✓

Explanation: Carbon has the highest melting point, due to it having 4 strong covalent bonds which require a lot of energy to break.

Q131. When elements of group II-A (alkaline earth metals) are exposed to air, they quickly become coated with a layer of oxide. What is the purpose of this oxide layer?

• A. The oxide layer exposes the metal to Atmospheric attack
• B. The oxide layer increases the reactivity of metal
• C. The oxide layer protects the metal from further atmospheric attack✓
• D. The oxide layer gives the metal a shiny silvery appearance

Explanation: The oxide layer can not react with air, and makes a physical barrier between air and metal.

Q132. In silicon dioxide each silicon atom is tetrahedrally bonded to four oxygen atoms and each oxygen atom is bonded to two silicon atoms. The ratio of silicon to oxygen atoms is:

• A. 2:2
• B. 1:2✓
• C. 2:1
• D. 1:4

Explanation: Ratio of silicon to oxygen atoms in silicon dioxide is 1:2 (SiO2).

Q133. Hydrogenation of unsaturated oils is done by using:

• A. Finely divided nickel✓
• B. Finely divided iron
• C. Vanadium pentaoxide
• D. Copper

Explanation: The hydrogenation of unsaturated oils is done under high temperature and pressure with nickel used as a catalyst.

Q134. Pick the correct statement:

• A. Chelates are usually more stable than ordinary complexes✓
• B. Ordinary complexes are more stable than chelates
• C. Monodentate ligands form the chelates complexes
• D. Chelates have no ring structures

Explanation: Chelate ligands can form a ring with central metal. Therefore it can regulate electrons within a ring. Because of this there is more force of attraction between the central metal ion and the chelating agent, therefore, they are more stable than ordinary complexes.

Q135. In contact process, the catalyst used for the conversion of Sulphur dioxide to Sulphur trioxide is:

• A. Magnesium oxide
• B. Aluminum oxide
• C. Silicon dioxide
• D. Vanadium pentoxide✓

Explanation: Vanadium pentoxide or Vanadium(V) oxide is used as a catalyst.

Q136. The unpolluted natural rainwater is slightly acidic due to the reaction of rain water with:

• A. Sulphur dioxide
• B. Oxides of nitrogen
• C. Carbon dioxide✓
• D. Hydrogen present in air

Explanation: Unpolluted rain has a slightly acidic pH of 5.6, because carbon dioxide and water in the air react together to form carbonic acid, a weak acid. Also note that unpolluted air would not have A and B, hence C is the correct choice.

Q137. In the Haber process for manufacturing of ammonia, Nitrogen is taken from:

• A. Proteins occurring in living bodies
• B. Ammonium salts obtained industrially
• C. Air✓
• D. Minerals containing nitrates

Explanation: In the Haber process, Nitrogen is obtained from the air, which contains about 78% nitrogen gas. The air is compressed and then passed through a catalyst bed along with hydrogen gas at a high temperature and pressure. The nitrogen gas reacts with hydrogen gas in the presence of an iron catalyst to form ammonia gas. Haber process is an important industrial process for the production of ammonia, which is a key component in the manufacture of fertilizers, explosives, and other chemical compounds.

Q138. In comparison with oxygen gas, a strong triple bond is present between two nitrogen atoms in a molecule and therefore nitrogen gas is:

• A. Highly reactive gas
• B. Completely inert like noble gases
• C. Very less reactive gas✓
• D. Moderately reactive gas

Explanation: Nitrogen (N₂) has a strong triple bond (N≡N) with very high bond energy (~946 kJ/mol), making it chemically stable and less reactive under normal conditions. However, it is not completely inert like noble gases — it can react under specific conditions (e.g., lightning, high temperature, or with catalysts in the Haber process).

Q139. The compound with an atom, which has unshared pair of electrons is called:

• A. Nucleophile✓
• B. Electrophile
• C. Protophile
• D. None of the given options

Explanation: Nucleophiles contain an unshared pair of electrons, and they look for a positive ‘centre’ to bond with.

Q140. 1-chloropropane and 2-chloropropane are isomers of each other, the type of isomerism in these two is called:

• A. Cis-trans isomerism
• B. Chain isomerism
• C. Position isomerism✓
• D. Functional group isomerism

Explanation: Positional isomers are constitutional isomers that have the same carbon skeleton and the same functional groups but differ from each other in the location of the functional groups on or in the carbon chain. The position of chlorine atom differs in both the compounds and they have the same carbon skeleton and same functional groups.

Q141. Benzene in the presence of AlCl3 produces acetophenone when reacts with:

• A. Acetyl chloride✓
• B. Acetic acid
• C. Ethyl benzene
• D. Ethanoic acid

Explanation: The benzene reacts with acetyl chloride in presence of anhydrous aluminum chloride to form acetophenone.

Q142. The substitution of a '-H' by '-NO2' group in benzene is called:

• A. Nitration✓
• B. Ammonolysis
• C. Sulphonation
• D. Reduction of benzene

Explanation: Nitration reactions are the addition of a nitro group into an organic compound. So addition of NO2 group in a benzene ring would also be a nitration reaction.

Q143. When purely alcoholic solution of sodium/potassium hydroxide and halogenoalkanes are reacted an alkene is formed, what is the mechanism of reaction?

• A. Elimination✓
• B. Dehydration
• C. Debromination
• D. Reduction of benzene

Explanation: Halogenoalkanes also undergo elimination reactions in the presence of sodium or potassium hydroxide forming an alkene.

Q144. The organic compound carbon tetrachloride is used as:

• A. Lubricant
• B. Solvent✓
• C. Oxidant
• D. Plastic

Explanation: Carbon tetrachloride (CCl4) is used as a solvent in industries.

Q145. An alcohol is converted to an aldehyde with same number of carbon atoms as that of alcohol in the presence of K2Cr2O7/H2SO4 the alcohol is:

• A. CH3Cl(CH)2OH
• B. CH3CH2CH2OH✓
• C. (CH3)3COH
• D. (CH3)3CHOH

Explanation: (B) is a PRIMARY alcohol and would be oxidised to an aldehyde with the same number of carbon atoms.

Q146. Which of the following is a secondary alcohol?

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

Explanation: Carbon atom that carries the -OH group is attached to two alkyl groups.

Q147. Which enzyme is involved in the fermentation of glucose:

• A. Zymase✓
• B. Invertase
• C. Urease
• D. Diastase

Explanation: Zymase is the enzyme that catalyses the fermentation of sugar into ethanol and carbon dioxide.

Q148. Relative acidic strength of alcohol, phenol, water and carboxylic acid is:

• A. Carboxylic acid > Alcohol > Phenol > Water CH3
• B. Carboxylic acid > Phenol > Water > Alcohol✓
• C. Phenol > Carboxylic acid > Alcohol > Water
• D. Water > Alcohol > Phenol > Carboxylic acid

Explanation: The acidity of a molecule depends on the stability of its ions after releasing the H+, the more stable the negative ion is the more acidic a molecule is. The acidity of a carboxylic acid is higher than alcohols and phenols. Because of the carboxylate ion, the conjugate base of a carboxylic acid is stabilized by two equivalent resonance structures in which the negative charge is effectively delocalized between two more electronegative oxygen atoms. For phenols, the phenoxide ion obtained after the removal of a proton is stabilized by resonance (in the benzene ring) whereas the alcohol ion obtained after the removal of a proton from alcohols is destabilized by the +I Effect of the alkyl group attached. Therefore, phenol is a stronger acid than alcohols, On the other hand, alcohol is a weaker acid than water because electron releasing alkyl group in alcohol increases the electron density of oxygen, and hence the polarity of the O−H bond in ethanol decreases which results in the decreasing acidic strength, Hence, acidic strength increases in the order given above.

Q149. Consider the following reaction:R―CHO + 2[Ag(NH3)2]OH → R―COONH4 + 2Ag + 2NH3 + H2O. This reaction represents one of the following tests?

• A. Fehling's test
• B. Benedict's test
• C. Ninhydrin's test
• D. Tollen's test✓

Explanation: First indication; [Ag(NH3)2]OH is the Tollen’s reagent. Second indication; reacts with an aldehyde to form silver (silver mirror test for aldehydes).

Q150. In the below reaction, the nucleophile is:

• A. CN-✓
• B. HCl
• C. Cl
• D. OH

Explanation: CN- breaks away from HCN in a heterolytic manner where CN- gets the lone pair also leaving behind H+. CN- acts as a nucleophile and attacks the partial positive carbon atom in HCHO.

Q151. Which one of the following compounds belongs to the homologous series of aldehydes?

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

Explanation: Homologous series is a family of hydrocarbons with similar chemical properties who share the same general formula. So for aldehydes RCHO is the general formula and HCHO would be the first member of homologous series of aldehydes, CH3CHO and CH3CH2CHO would be the 2nd and 3rd respectively.

Q152. The products of the reaction given below are:CH3COOH + PCl5 → ?

• A. CH3COCl + POCl3 + HCl✓
• B. CH3COCl + POCl2 + HCl
• C. CH3Cl + POCl3 + HCl
• D. CH3COCl + POCl3 + H2

Explanation: The reaction of a carboxylic acid (acetic acid in this case) and PCl5 produces an acyl chloride (CH3COCl in this case) along with POCl3 and HCl.

Q153. CH3CN +H2O + HCl → A + B In the reaction given above, A and B are:

• A. Acetic acid and acid amide
• B. Acetic acid and methyl chloride
• C. Acetic acid and ammonia
• D. Acetic acid and ammonium chloride✓

Explanation: The acid-catalyzed hydrolysis of a nitrile (CH3CN) first produces an amide, which is then further hydrolyzed to a carboxylic acid (acetic acid. A). The nitrogen from the nitrile combines with the acid (HCI) and water to form an ammonium salt (ammonium chloride, B).

Q154. Consider the following reaction:CH3COOH + Mg (metal) → ?What product will form?

• A. Magnesium formate
• B. Magnesium acetate✓
• C. Magnesium ion
• D. Carboxylate ion

Explanation: Carboxylic acids react with active metals to form hydrogen and metal carboxylates, without changing the carbon chain. So CH3COOH (acetic acid) would make magnesium acetate.

Q155. The ―NH―CO is called:

• A. Amide group
• B. Amino group
• C. Protein linkage
• D. Peptide linkage✓

Explanation: -NH-CO- is a peptide linkage bond, done when 2 amino acids are joined together.

Q156. Which one of the following is an alpha amino acid?

• A. Glycine✓
• B. Serine
• C. Glutamine
• D. Lysine

Explanation: The amino acids having amino and carboxyl group attached to the same carbon, i.e, alpha-carbon atom is called alpha-amino acids.

Q157. Which of the following has an amino R-group?

• A. Lysine✓
• B. Proline
• C. Valine
• D. Alanine

Explanation: Lysine has an amino in it’s R-group chain i.e.NH2.

Q158. At intermediate value of pH, amino acids form Zwitter ions containing:

• A. ―NH3+ and COO-✓
• B. ―NH3 and COO-
• C. ―NH3+ and COOH
• D. ―NH3 and COOH

Explanation: Intermediate value means under neutral conditions. So in that circumstance amino acids produce NH3+ and COO- zwitter ions.

Q159. When hexane dioic acid is heated with hexamethylene diamine, the compound formed is:

• A. Polypeptide
• B. Addition polymer
• C. Ester
• D. Nylon 6,6✓

Explanation: Nylon-6,6 is made by polymerising hexanedioic acid and hexamethylene diamine (adipic acid).

Q160. A polymer in which the number of amino acid residue is greater than 100 or molecular mass is greater than 1000, is known as:

• A. Protein
• B. Polypeptide✓
• C. Dipeptide
• D. Tripeptide

Explanation: The correct answer is Polypeptide. Polypeptides are chains of amino acids that are longer than 100 residues or have a molecular mass greater than 1000. Unlike proteins, which are functional and often consist of multiple polypeptides folded into a specific shape, a polypeptide is simply a long chain of amino acids. Option A, Protein, is incorrect because while proteins are made of one or more polypeptides, the question specifies the polymer itself, not its functional form. Option C, Dipeptide, is incorrect as it only consists of two amino acids, far less than 100. Option D, Tripeptide, is similarly incorrect because it only consists of three amino acids.

Q161. Aspartic acid is an acidic amino acid, which has chemical formula:

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

Explanation: Aspartic acid has an α-amino and α-carboxyl plus a side chain CH2-COOH, i.e. H2N-CH( CH2-COOH )-COOH, which matches structure C.

Q162. Glucose and fructose are common examples of:

• A. Pentoses
• B. Hexoses✓
• C. Heptoses
• D. Butoses

Explanation: Hexoses are simple sugars with 6 carbon atoms with the chemical formula C6H12O6. Glucose and fructose are both hexoses with different structural formulas.

Q163. The reaction between fats and caustic soda is called:

• A. Hydrogenolysis
• B. Fermentation
• C. Carboxylation
• D. Saponification✓

Explanation: Saponification is a process that involves the conversion of fat, oil, or lipid (fats in this case) into soap and alcohol by the action of aqueous alkali (caustic soda in this case).

Q164. Macromolecules are described as large molecules built up from small repeating units known as:

• A. Monomers✓
• B. Isomers
• C. Metameres
• D. Tautomer

Explanation: A macromolecule is a very large molecule. That are composed of many covalently bonded atoms. Macromolecules are polymers of smaller molecules called monomers.

Q165. Polyvinyl chloride is an example of:

• A. Addition polymer✓
• B. Condensation polymer
• C. Biopolymer
• D. Thermosetting polymer

Explanation: Polyvinyl chloride (PVC) is an addition polymer of chloroethene and has a general formula of (C2H3Cl)n.

Q166. Terylene, a polyester is an example of:

• A. Biopolymer
• B. Lipids
• C. Condensation polymer✓
• D. Addition polymer

Explanation: PolyESTERS (polymers of esters) are mostly made by condensation polymerisation reactions, making them condensation polymers.

Q167. The suspected liver carcinogen which also has negative reproduction and developmental effects on humans is:

• A. Iodoform
• B. Bromoform
• C. Tropoform
• D. Chloroform✓

Explanation: Chloroform is a carcinogen, causing liver and kidney cancer after oral exposure, and has negative effect on reproduction and development of humans (and animals).

Q168. Peroxyacetyl nitrate is an irritant to human beings and it effects:

• A. Nose
• B. Stomach
• C. Ears
• D. Eyes✓

Explanation: Peroxyacetyl nitrates (PANs) have many adverse effects in the human body such as reduced respiratory function (including emphysema and impaired breathing) and eye irritation.

Q169. When the dimensions of both sides of an equation are equal, then the equation is said to be:

• A. Simultaneous
• B. Homogeneous✓
• C. Instantaneous
• D. Quadratic

Explanation: A dimension equation is said to be homogeneous, only and only if dimensions of equations are same on both sides.

Q170. Radian is a unit of angular displacement that can also be measured in degrees. How many radians are equal to one degree?

• A. 180/π
• B. π/180✓
• C. 2π/180
• D. π/57.3

Explanation: One radian is equal to 180/π degrees. Thus, to convert from radians to degrees, multiply by 180/π, hence option B is correct one.

Q171. An elevator is moving upwards with constant velocity of ‘v’. What is the weight of a person of a mass ‘m’ inside the elevator during upward motion?

• A. mg + mv
• B. mg✓
• C. mg ― mv
• D. Zero

Explanation: The weight of an object is defined as the force of gravity on the object and is calculated as the mass times the acceleration of gravity, w = mg. This does not change when the elevator is moving because it doesn't effect the mass of the person and the gravitational acceleration.

Q172. An object having spherical shape of radius ‘r’ experiences a retarding force F from a fluid of coefficient of viscosity ‘η’ when moving through the fluid with speed ‘v’. What is the ratio of retarding force to speed?

• A. 6πη r2
• B. 6πη/r2
• C. 6πη r✓
• D. 6πη/r

Explanation: Retarding force=6πη r v. ratio of retarding force to speed (v) would be (6πη r v)/v which equals 6πη r.

Q173. When the drag force is equal to the weight of the droplet, the droplet will fall with:

• A. High Speed
• B. Low Speed
• C. Certain acceleration
• D. Constant Speed✓

Explanation: When the downward (weight) and upward (drag) forces are equal in a falling body, the body is said to be in terminal velocity, which means that the body falls with a constant speed since there is no resultant force acting on it.

Q174. A simple pendulum length ‘L’ with bob of mass ‘m’ is slightly displaced from its mean position so that it string makes an angle ‘θ’ with vertical line as shown in the figure. Then bob of pendulum released. What will be the expression of torque with which the bob starts to move towards the mean position?

• A. mgL
• B. mgL sin θ✓
• C. 0
• D. mgL cos θ

Explanation: Torque is the rate of change of angular momentum of an object T=force*radius*sinθ, in this case, force is the weight of the pendulum (mg) and radius is the length of the string.

Q175. The density of blood is:

• A. Less than water
• B. Nearly equal to water✓
• C. Greater than water
• D. Three times that of water

Explanation: Density of water is 1000 kg per metre cube, and the density of blood is 1060 kg per metre cube, making them nearly equal.

Q176. A monochromatic light of wavelength ‘λ’ is used to produce the diffraction pattern through a single slit of width X. Which one of the following represents the intensity distribution across the screen?

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

Explanation: Monochromatic light passing through a single slit has a central maximum and many smaller and dimmer maxima on either side.

Q177. For interference of light waves to take place, the required condition is:

• A. The path difference of the light waves from the two sources must be large
• B. The interfering waves must be non-coherent
• C. The light waves may come from different sources
• D. The light waves must come from two coherent sources✓

Explanation: For light waves to successfully interfere the sources of the waves must be coherent, which means they emit identical waves with a constant phase difference and the waves should be monochromatic (single wavelength).

Q178. The property of bending of light around an obstacle and spreading of light waves into a geometric shadow of an obstacle is called:

• A. Diffraction of Light✓
• B. Polarization of Light
• C. Quantization of Light
• D. Interference of Light

Explanation: The phenomenon of bending of light around the corners of obstacles in the path of light and spreading into the regions of geometrical shadow is known as diffraction.

Q179. The normal human eye can focus a sharp image of an object on the eye if the object is located at certain distance called:

• A. Least Point
• B. Near Point✓
• C. Far Point
• D. Distinct Point

Explanation: Near point is the point nearest the eye at which an object is accurately focused on the retina at full accommodation, making a sharp image.

Q180. A source of sound wave emits waves of frequency ‘f’. If ‘v’ is speed of sound waves, then what will be the wavelength of the waves:

• A. v/f✓
• B. vf
• C. (v-uo) / f
• D. (v−uo) f

Explanation: Formula wavelength=velocity/frequency.

Q181. The spectrum of a star’s light is measured and the wavelength of one of the lines as the sodium’s line is found to be 589 nm. The same line has the wavelength of 497 nm when observed in the laboratory. This means the star is:

• A. Moving away from the earth✓
• B. Moving towards the north
• C. Stationary
• D. Revolving around the planet

Explanation: When the wavelength of star was measured it resembled to the wavelength of sodium having wavelength 589 nm and when the sodium line was observed in the lab, its wavelength was calculated it came out to be 497nm . this means the wavelength had increased and it increases when star moves away.

Q182. What is the period of the mass-spring system during SHM if the ratio of mass to spring constant is ¼?

• A. π✓
• B. 2 π
• C. 1/π
• D. ½ π

Explanation: T=2 π √(m/k). Where m/k is ¼. After replacing values T=2 π √(1/4) which equals to π.

Q183. The waveform of SHM is given in the figure. At what time/times displacement is equal to zero?

• A. T/4 only
• B. 3T/4
• C. 0, T/4, 3T/4 and T
• D. 0, T/2 and T✓

Explanation: As seen on the graph displacement is 0 on points A,C and T (at the end) which are times 0, T/2 and T.

Q184. A wire is stretched by a force that causes an extension. The energy is stored in it only when:

• A. The extension of wire is proportional to force applied✓
• B. The cross-section area of the wire remains constant
• C. The wire is not stretched beyond its elastic limit
• D. The weight of wire is negligible

Explanation: The energy stored in the wire is potential energy, when the wire is extended proportionally to the force applied PE=½ kx2. (c) is not a valid answer because the wire would still hold potential energy even when its stretched beyond its elastic limit.

Q185. Which of the following statements is correct:

• A. Elasticity is that property of body which enables body to regain its original dimension
• B. Elasticity is that property of a body that does not allow it to return to its original shape
• C. Elasticity is that property of a body that allows it to retain its original shape and dimension after the stress is removed✓
• D. Elasticity is that property of a body that obeys Hooke’s law

Explanation: Elasticity is the ability of a deformed material body to return to its original shape and size when the forces causing the deformation are removed.

Q186. Which of the following is the expression of root mean square speed of a gas having n number of molecules contained in the container?

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

Explanation: Root mean square speed of a gas = square root ((sum of squares of all molecules)/number of molecules).RMS value can be calculated by taking a mean of the sum of the square of the speeds of all molecules present in a container

Q187. For a gas of volume V in its equilibrium state, if the pressure does change with time then total kinetic energy of gas is constant because:

• A. Collisions between gas molecules occur
• B. Collisions between gas molecules occur linearly
• C. Collisions must be elastic✓
• D. Collisions must be inelastic

Explanation: Elastic collisions conserve total kinetic energy and momentum, hence total kinetic energy of the gas remains unchanged.If the pressure is changing with time and collisions are elastic, it implies that the average kinetic energy of the gas molecules, and hence the temperature, remains constant. This is because in elastic collisions, there is no net loss or gain of kinetic energy.It's important to note that this statement applies to ideal gases under the specific conditions mentioned. Real gases may exhibit deviations from ideal behavior, especially at high pressures and low temperatures.

Q188. Which of the following is the proper way to study the sinusoidal waveform of the voltage?

• A. Voltage is connected to X input and the time base is switched off
• B. Voltage is connected to Y input and the time base is switched on✓
• C. Voltage is connected to Y input and the time base is switched off
• D. Voltage is connected to X input and the time base is switched on

Explanation: Voltage should be connected to Y and time base switched on.

Q189. The electron gun in a cathode ray oscilloscope contains:

• A. Filament, cathode, grid, anodes✓
• B. Cathode, anode, capacitor, screen
• C. Emitter, base, collector
• D. Resistance, capacitor, inductor

Explanation: The beam of the electrons is provided by an electron gun which consists of an indirectly heated cathode, a grid and three anodes.

Q190. In which of the following, the change in internal energy is more?

• A. In system A
• B. In system B
• C. Cannot be predicted
• D. Change is zero in both. (both are cyclic)✓

Explanation: In a cyclic process, the system undergoes a series of changes and returns to its initial state. The change in internal energy ΔU for the entire cyclic process is zero because the internal energy is a state function, and it depends only on the initial and final states, not on the path taken.

Q191. Pressure volume graph of two systems 'A' and 'B' are plotted under isothermal and adiabatic conditions. Which of the following observation of graph represents the two systems?

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

Explanation: Adiabatic expansion and compression are characterized by a more rapid change in pressure and volume. Isothermal expansion and compression are characterized by a slower change in pressure and volume compared to adiabatic processes. the specific path on the PV diagram depends on the particular conditions and constraints of the process. The key difference lies in the rate at which the changes in pressure and volume occur. The isothermal process has a more gradual change, while the adiabatic process has a more rapid change.

Q192. Which of the following curve is an isotherm?

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

Explanation: In the context of thermodynamics and gas behavior, an "isotherm" refers to a curve or line on a graph representing a process that occurs at constant temperature. The term "isotherm" is commonly associated with the pressure-volume (PV) diagram for ideal gases.For an ideal gas undergoing an isothermal process, the relationship between pressure (P) and volume (V) is given by the equationPV=nRT, where nRT are constants in isothermal process (no temperature change) On a PV diagram, this relationship corresponds to a hyperbolic curve.

Q193. If 2 A current passes through a resistor when connected to a certain battery. If the resistance is replaced by double the resistance, then the current will become:

• A. 2 A
• B. 4 A
• C. 6 A
• D. 1 A✓

Explanation: Formula V/I=R, V remains constant so if the resistance is doubled then current would be halved, V / 0.5 I=2R. Since initial current was 2A the new current would be 1A.

Q194. In a Helium-Neon laser, population inversion of _ atoms is achieved which emits radiations, when they are stimulated to fall at a lower level.

• A. Neon
• B. Helium
• C. Helium and Neon✓
• D. Chromium

Explanation: In a Helium-Neon laser, population inversion of C. Helium and Neon atoms is achieved which emit radiations, when they are stimulated to fall to a lower energy level.

Q195. Three resistors each having value 'R' are connected as shown in figure. What is the equivalent resistance between 'X' and 'Y'?

• A. 3R✓
• B. R
• C. R/3
• D. R3

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

Q196. If the number of turns of a solenoid circular coil is doubled, but the current in the coil and radius of the coil remain the same, then what will be the magnetic flux density produced by the coil?

• A. Magnetic flux density will be halved
• B. Magnetic flux density increases by different amount at different points
• C. Magnetic flux density remains unchanged✓
• D. Magnetic flux density will be doubled

Explanation: When the number of turns N is doubled but the solenoid length L also doubles, the magnetic flux density B=μ0(NI/L) remains the same. Therefore, there is no change in B.

Q197. Two long parallel wires Wire 1 and Wire 2 repel each other as shown in the figure. What could be the reasons?

• A. Both carry current in same direction
• B. Both carry current in opposite direction✓
• C. Wire 1 has current, but Wire 2 has no current
• D. Wire 2 has current, Wire 1 has no current

Explanation: Two parallel wires have currents travelling in opposite directions, the magnetic fields generated by those currents between the wires will both point in the same direction (use right hand grip rule). Thus, wires would repel each other.

Q198. The diagram shows a wire, carrying a current 'I', placed between the poles of a magnet. In which direction does the force on the wire act?

• A. Upwards
• B. Downwards✓
• C. Towards the ‘N’ pole of the magnet
• D. Towards the ‘S’ pole of the magnet

Explanation: We can determine the direction of the force on the current-carrying wire using Fleming's Left-Hand Rule.Step-by-step explanation:Magnetic field direction (B):It is from the North (N) pole to the South (S) pole (left to right).Current direction (I):The current is going upwards (as shown by the arrow labeled I).Force direction (F):By Fleming's Left-Hand Rule:First finger = Magnetic field (left to right),Second finger = Current (upwards),Thumb = Force (direction of motion).When you align your left hand as per this rule, the thumb points out of the page (towards you).

Q199. Wavelength of X-rays is the order of:

• A. 10-6 m
• B. 10-10 m✓
• C. 10-13 m
• D. 100 m

Explanation: X-ray wavelength is in range of 10−11 m to 10−8 m.

Q200. Laser beam can be used to generate three-dimensional image of object in a process called:

• A. Computed technology
• B. Computed tomography
• C. Holography✓
• D. Computerized axial tomography

Explanation: Holography is a technique based on wave interference to record and form three-dimensional images. Lasers offer a practical way to produce sharp holographic images because of their monochromatic and coherent light for pronounced interference patterns.

Q201. Which of the following is true for Lasers?

• A. Electrons are emitted
• B. Stimulated emission of electrons is needed
• C. Coherent monochromatic light is emitted✓
• D. There is a population inversion of photons

Explanation: A and B are incorrect because photons are emitted. D is incorrect because population inversion of atoms is achieved. C is correct because it is true that a laser emits coherent and monochromatic light.

Q202. Three resistors of resistance R1, R2, and R3 are connected as shown in the figure.The equivalent resistance is:

• A. Option A
• B. Option B
• C. Option C
• D. Option D
• E. None of the above✓

Explanation: (All options are wrong) R2 and R3 are connected in parallel, so their total resistances would be RT=(R2R3)/(R2+R3). And then R1 is connected in series so the equivalence resistance would be the sum of R1 and the total resistance in the parallel resistors, which would be R1+((R2R3)/(R2+R3)) which equals to (R1R2+R2R3+R3R1)/(R2+R3).

Q203. What is meant by spontaneous emission of electrons in solids?

• A. Electrons being emitted by the solids through photoelectric effect when irradiated with electromagnetic radiation
• B. Incident electrons colliding with electrons in solids and releasing doubling the number of incident electrons
• C. Electrons in solids are emitted without any external stimulus through radiation
• D. Excited electrons going back to lower energy states immediately by releasing energy.✓

Explanation: Spontaneous emission is the process in which a molecule, an atom or a subatomic particle transits from an excited energy state to a lower energy state (e.g., its ground state) and emits a quantized amount of energy in the form of a photon.

Q204. When electrons lose all their kinetic energy in the first collision, the entire kinetic appears as an X-ray photon of energy:

• A. K.E. = eV✓
• B. K.E. = hλmin/c
• C. K.E. = hc/λmin
• D. K.E. = h/λmax

Explanation: According to the photoelectric equation:(KE)max = Energy of incident photon - Work functionOnly A is correct because eV is one way of representing (KE)max. Options B, C, and D do not denote (KE)max.

Q205. The characteristic X-ray spectrum is due to:

• A. The absorption of neutrons by target material
• B. The bombardment of target material by protons
• C. The bombardment of target material by electrons✓
• D. The bombardment of target material by alpha particles

Explanation: The characteristic x-rays are obtained due to the transition of electron from inner orbits of the atoms, so the target is bombarded by electrons.

Q206. The ionizing capability of gamma rays is:

• A. Equal to alpha and beta particle
• B. Less than alpha but greater than beta particles
• C. Less than both alpha and beta particles✓
• D. Less than beta but greater than alpha particles

Explanation: Ionizing capability is the strongest in alpha particles then beta particles and weakest in gamma rays.

Q207. The half-life of a radioactive element is:

• A. Inversely proportional to square of decay constant
• B. Directly proportional to square of decay constant
• C. Directly proportional to decay constant
• D. Inversely proportional to decay constant✓

Explanation: Formula for half life is T= 0.693/λ, so half life in inversely proportional to decay constant.

Q208. The transformation of a neutron into proton in the nucleus, gives rise to emission of:

• A. Beta particles✓
• B. Gamma particles
• C. Alpha particles
• D. X-rays

Explanation: Option A is correct because the transformation of a neutron into a proton in the nucleus gives rise to the emission of a beta (β) particle. This process is known as beta decay. In beta decay, a neutron inside the nucleus undergoes a transformation where it is converted into a proton, emitting a beta particle in the process. The beta particle can be either a beta-minus (β-) particle, which is an electron (e⁻), or a beta-plus (β+) particle, which is a positron (e⁺).

Q209. The ratio of the rate of decay of a parent atom to the number of radioactive nuclei present at that time is equal to:

• A. Half-life of radioactive element
• B. Mean life
• C. Decay constant of radioactive element✓
• D. Activity of radioactive element

Explanation: Let the initial number of atoms at time t=0 be N0.Let N be the number of atoms at any instant t.λ is the disintegration constant.We can write that:dN/dt = −λNλ = -dN/dt / N

Q210. Which one of the following particles is emitted as a result of the following nuclear reaction?Ra226 → Rn222

• A. Beta
• B. Alpha✓
• C. Gamma rays
• D. One alpha and one beta

Explanation: Alpha particle has mass of 4 amu. And the mass number is reduced by 4 amu (from 226 to 222) hence indicating an alpha particle was emitted.

Q211. Which of the following is used to estimate the circulation of blood in a patient?

• A. Carbon-14
• B. Carbon-12
• C. Phosphorus-3
• D. Sodium-24✓

Explanation: Salt solutions containing compounds of sodium-24 are injected into the bloodstream to help locate obstructions to the flow of blood and estimate the circulation of blood flow.

Q212. For the radiotherapy of a patient, it is required to double the absorbed dose in gray. What step must be taken?

• A. Energy must be quadrated
• B. Energy must be halved
• C. Energy must be raised four times
• D. Energy must be doubled✓

Explanation: According to formula D=E/m, if the dose needs to be doubled the energy must be doubled.

Q213. 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.

Q214. 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.

Q215. 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.

Q216. 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'.

Q217. Change the voice of the statement;"Work hard."

• A. Let the work be hard
• B. Work be hard
• C. Let you work be hard
• D. You are advised to work hard✓

Explanation: - The original sentence "Work hard" is an imperative sentence, which is a command or instruction.- To convert it to a declarative sentence (a statement), we need to add a subject and a verb. Hence, the correct declarative sentence is "You are advised to work hard".

Q218. Convert into Passive Voice"She spoke to the official on duty."

• A. The official on duty was spoken to by her.✓
• B. The official was spoken to by her on duty.
• C. She was spoken to by the official on duty.
• D. She was the official to be spoken to on duty.

Explanation: - The original sentence "She spoke to the official on duty" is in active voice, where the subject "she" performs the action of speaking.- To convert it to passive voice, we need to make the official on duty the subject, and the action (speaking) is performed on them. Hence, the correct passive voice construction is "The official on duty was spoken to by her".

Q219. Convert into Passive Voice;"The doctor advised the patient not to eat rice."

• A. The patient was advised by the doctor not to eat rice.✓
• B. The patient was advised by the doctor that he should not eat rice.
• C. The patient was being advised by the doctor that he should not rice by the doctor.
• D. The patient has been advised not to eat rice by the doctor.

Explanation: This option uses the passive voice to report the original sentence, maintaining the same meaning and tense. The phrase "was advised" indicates the patient received the advice, and "not to eat rice" is the content of the advice.

Q220. Convert into Passive Voice;''I cannot accept your offer."

• A. Your offer cannot be accepted by me.✓
• B. I cannot be accepted by your offer.
• C. The offer cannot be accepted by me.
• D. Your offer cannot be accepted.

Explanation: The correct answer is Option A: 'Your offer cannot be accepted by me.' This conversion maintains the meaning of the original active voice sentence, 'I cannot accept your offer,' by making 'your offer' the subject of the passive sentence. The verb phrase 'cannot be accepted' correctly uses the passive voice, and 'by me' specifies the agent.Option B is incorrect because it changes the meaning, implying that 'I' is being accepted, which is not the case in the original sentence.Option C, while similar in construction, uses 'The offer' instead of 'Your offer,' which alters the original intent slightly.Option D removes the agent entirely, losing the specific information about who cannot accept the offer, which is essential for accurately conveying the original sentence's meaning.