Kpk Mdcat Mock Paper 3 — Solved Past Paper with Answers

Q1. Choose the correct spelling:

• A. Exantuated
• B. Axantuated
• C. Accenchuated
• D. Accentuated✓

Explanation: To "accentuate" means to “make more noticeable and prominent” and its correct spelling is given in Option D.

Q2. The headmaster _ to speak to you.

• A. Wants✓
• B. Is wanting
• C. Was wanting
• D. Want

Explanation: “The headmaster wants to speak to you” in Option A sounds most appropriate because "headmaster" is a singular noun so we should complement it with a singular verb - eliminating Option D. The tense is simple present indicated by the verb "speak", hence the present continuous form "is wanting" in Option B is also incorrect. while the past tense form in Option C is also incorrect.

Q3. Identify the errors and choose the correct option: I hope this letters finds in the best of your spirits.

• A. I hope this letter will find you in good of high spirits.
• B. I hope this letter finds you in the best of your spirit.✓
• C. I hope letter finds you in the best of spirits.
• D. I hope the letter found in greatest of sprite.

Explanation: There are two grammatical errors in the sentence above. An object (pronoun/noun) should be used to correctly identify the entity to whom the letter is sent. Option A is incorrect since it makes use of the future tense – indicated by “will find” – while the person will be reading the letter in the present. Option C and Option D are incorrect since they lack the determiner “this” which is necessary to indicate that the letter being mentioned is specific in nature (i.e. the letter that is being read currently). By elimination, Option B is correct.

Q4. He was _ in bed all day yesterday.

• A. Laying
• B. Lying✓
• C. Lieing
• D. Lied

Explanation: Lying in bed is correct. Both “laying” and “lying” are the present participles of the verbs “lay” and “lie.” Lay” is a transitive verb that refers to putting something in a horizontal position, while“lie” is an intransitive verb that refers to being in a flat position. Lieing in bed is not an option as the spelling is wrong.

Q5. He said to me, "Why have you come late?"[Indirect form of the sentence is:]

• A. He asked me why I had come late✓
• B. He asked me why I came late.
• C. He asked me why I have come late
• D. He told me as to why I had come late

Explanation: Reported or indirect speech is usually used to talk about the past, so we normally change the tense of the words spoken. We use reporting verbs like 'say', 'tell', and 'ask', and we may use the word 'that' to introduce the reported words. When the reporting verb is in the past tense (said) and the direct speech is in the past indefinite tense, then the indirect speech will change into the past perfect tense and if the sentence is interrogative, reporting verbs are used– asked, enquired, etc. Thus, Option A is the correct answer.

Q6. It has been raining continuously _ last night.

• A. Since✓
• B. For
• C. From
• D. With

Explanation: We use "for" with a period in the past, present, or future. For refers to periods, e.g. 3 years, 4 hours, ages, a long time, months, years.We use "since" with a point in time in the past. For example: "They’ve lived in Oxford for a couple of months." "They’ve lived in Oxford since 2004."

Q7. 'CHUCKLE‘ mean:

• A. Bouquet of flowers
• B. Displeasing manner
• C. Suppressed laughter✓
• D. Religious movement

Explanation: Chuckling is a form of laughter that is done in a quiet manner.

Q8. 'ARABLE‘ means:

• A. Not grown since long
• B. Recently ploughed field
• C. Watered the night before
• D. Fit for cultivation✓

Explanation: Arable refers to land suitable for growing crops.

Q9. Choose the correct sentence.

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

Explanation: In this corrected sentence: "Does" is the correct auxiliary verb used with a singular subject to form a question in the present tense. "your" is the possessive pronoun, indicating that the train belongs to the person being addressed. "train" is the noun representing the mode of transportation. "leave" is the main verb, representing the action of the train departing or starting its journey. "before eight o'clock" is a prepositional phrase indicating the time when the action (leaving) is happening. With the "Does" correction, the sentence now asks whether the person's train departs or starts its journey before 8 o'clock. It is grammatically correct and properly formed.

Q10. I keep the butter in the fridge. Select the correct passive voice:

• A. In the fridge the butter is kept by me.
• B. By me is the butter dept in the fridge.
• C. The butter is kept by me in the fridge.✓
• D. Dept in the fridge by me is the butter.

Explanation: A verb is in the passive voice when the subject of the sentence is acted on by the verb. For example, in “The ball was thrown by the pitcher,” the ball (the subject) receives the action of the verb, and was thrown is in the passive voice.

Q11. Fire destroyed the top floor of the building:

• A. The top floor of the building got destroyed by fire
• B. By fire was destroyed the top floor of the building.
• C. Destroyed by fire was the top floor of the building.
• D. The top floor of the building was destroyed by fire✓

Explanation: Option D has the correct punctuation, grammar and past tense hence it is correct. The rest of the options are incoherent hence incorrect.

Q12. Select the correct sentence:

• A. He does not know the reason of her absence.
• B. He does not know the reason around her absence.
• C. He does not know the reason for her absence.✓
• D. He does not know the reason about her absence.

Explanation: The preposition for is used both after and before reason. Therefore, the grammatically correct sentence is "He does not know the reason for her absence". Reason can also followed by a clause beginning with why or that.

Q13. An 'ELEGY‘ is a poem written:

• A. In the memory of a little child
• B. On the sighting of an old tutor
• C. In the love of dear sweetheart
• D. On the death of someone dear✓

Explanation: An elegy is a form of poetry in which the poet or speaker expresses grief sadness, or loss and is traditionally written in response to the death of a person or group. Therefore the answer is D.

Q14. (Fix this) Select the correct sentence:

• A. Certainly she is the best person for the job.
• B. She is the best person for the job certainly.
• C. She is certainly the best person for the job.✓
• D. The best person certainly she is for the job.

Explanation: This sentence is grammatically correct and has a natural flow. "Certainly" is placed directly before "the best person", which makes it clear that it's modifying that phrase.

Q15. The culpable child _ some words to her mother for pardoning his delinquency.

• A. Mumbled✓
• B. Showy
• C. Rude
• D. Crazy

Explanation: 'Mumbled' is to say something indistinctly and quietly, making it difficult for others to hear. So, the correct sentence is, "The culpable child mumbled some words to her mother for pardoning his delinquency."

Q16. SPOT THE ERROR: In the following sentences, some segments of each sentence are underlined. Your task is to identify that underlined segment of the sentence, which contains the mistake that needs to be corrected. Thrifty housewives preserved their homegrown vegetables and fruits in canning, pickling or drying them for use during the cold weather.

• A. In✓
• B. Or
• C. For
• D. The

Explanation: A is incorrect, it should be by instead.

Q17. Indolence gives vent to _ disposition in human life.

• A. Static✓
• B. Enthusiastic
• C. Energetic
• D. Filthy

Explanation: Indolence refers to laziness or a lack of motivation or effort. When a person is indolent, they tend to be inactive or lethargic, resulting in a static disposition.

Q18. Bacteria living in the gut, forms the associationof:

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

Explanation: The human gut microbiome includes trillions of commensal bacteria that offer substantial benefits to the host, including aiding digestion, promoting the development of the immune system, and occupying niches that would otherwise be available to pathogens

Q19. "Foraminifers" helps to determine the,

• A. Generation time
• B. Geological age✓
• C. Ecological time
• D. Physiological age

Explanation: The geological time scale relates stratigraphy rock layers) to periods. Foraminifera are geologically short-lived and some forms are only found in specific environments. Therefore, a paleontologist can examine the specimens in a small rock sample like those recovered during the drilling of oil wells and determine the geologic age and environment when the rock formed.

Q20. Basidiomycota is also called as:

• A. Club-mosses
• B. Club-fungi✓
• C. Sac-fungi
• D. Bread mold

Explanation: Basidiomycota is a large and diverse phylum of fungi that includes jelly and shelf fungi; mushrooms, puffballs, and stinkhorns; certain yeasts; and rusts and smuts. Most species reproduce sexually with a club-shaped spore-bearing organ (basidium) that usually produces four sexual spores (basidiospores). They are also known as club fungi because of their club-shaped basidia. They are an important group with about 16,000 known species.

Q21. Termites cut wood with the help of enzyme produced by

• A. Trichonella
• B. Tripanosoma
• C. Trichonympha✓
• D. Trichina

Explanation: Although termites are insects that eat wood, they are not capable of digesting wood on their own. Endosymbionts that live within the intestines of the termite assist in converting the wood into nutrients that the termite can digest. One of the several types of endosymbionts that live inside the termite is single-celled organisms called Trichonympha (protozoa). Trichonympha has the enzymes needed to convert cellulose in wood into starches and sugars that the termite can use as nutrients.

Q22. CSF Is found in between:

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

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

Q23. Incubation period of ―"HCV" is:

• A. 2-6 weeks
• B. 4-10 weeks
• C. 4-20 weeks✓
• D. 4-26 weeks

Explanation: Hepatitis C is a viral infection that affects the liver. It causes inflammation and swelling, which damages the liver tissues over time. Hepatitis C is caused by a virus that spreads through contact with blood. Transmission occurs when the blood of an infected person enters the body of an uninfected person. Worldwide, transmission commonly occurs in medical settings with unsterilized equipment. An incubation period is the time between infection or contact with the agent and the onset of symptoms or signs of infection. The hepatitis C (HCV) window period is usually 4–20 weeks from the time of exposure. After 6 months, most people will have developed enough antibodies for an HCV test to detect. In rare cases, however, antibodies can take up to 9 months to develop.

Q24. Osteopenia starts at the age of:

• A. 30-40
• B. 30-35
• C. 40-45
• D. 50-60✓

Explanation: Osteopenia is a clinical term used to describe a decrease in bone mineral density (BMD) below normal reference values. Lower BMD indicates we have fewer minerals in our bones than we should, which makes bones weaker. Osteopenia is more common in people older than 50, especially women. Osteopenia isn’t as severe as osteoporosis, a disease that weakens bones so much that they can break more easily. Up until about age 30, a healthy person builds more bone than he or she loses. But after age 35, bones begin to break down faster than they build up. Some things can make bone loss happen more quickly, leading to osteopenia, such as medical conditions such as hyperthyroidism, hormonal changes during menopause, poor nutrition, especially a diet too low in calcium or vitamin D, and unhealthy lifestyle choices, such as smoking, drinking too much alcohol or caffeine, and not exercising.

Q25. The interval between two successive division of bacteria is called:

• A. Ecological time
• B. Population time
• C. Growth time
• D. Generation time✓

Explanation: Generation time is the time it takes for a population of bacteria to double in number or the interval between two successive divisions in bacteria. For many common bacteria, the generation time is quite short, 20-60 minutes under optimum conditions.

Q26. Most disease symptoms appear during.

• A. Lag phase
• B. Log phase✓
• C. Die
• D. Generation time

Explanation: After the lag phase, bacterial cells enter the exponential or log phase. This is the time when the cells are dividing by binary fission and doubling in numbers after each generation time. Metabolic activity is high as DNA, RNA, cell wall components, and other substances necessary for growth are generated for division. In humans, the disease symptoms develop during the log phase because the bacterial production attains such a high level which damages the tissues.

Q27. Endotoxins are released only when bacteria

• A. Excrete
• B. Reproduce
• C. Decline phase✓
• D. Stop phase

Explanation: At the decline phase, bacterial growth decreases exponentially and many bacteria begin dying due to lack of nutrients or unfavorable changes in body conditions. Endotoxins are components of bacterial gram-negative membranes that are released to the external environment when a bacterial cell dies. Bacteria don't excrete endotoxins as waste material.

Q28. The osmotic pressure of dilute solution is given by the formula:

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

Explanation: The formula for the osmotic pressure of a dilute solution is:π = CRT Where,C = Molar concentration of soluteR = Universal gas constantT = Absolute temperatureπ = osmotic pressure

Q29. Select the test used for the estimation of glucose in blood and urine?

• A. Tollen's reagent test
• B. Fehling's solution test
• C. Benedict solution test
• D. All of the above✓

Explanation: The tests mentioned in Options A, B, and C can all be used to detect the presence of glucose in blood and urine.

Q30. Basidiocarp is formed in the:

• A. Secondary mycelium
• B. Primary mycellum
• C. Tertiary mycelium✓
• D. Pathogenic parasites

Explanation: Basidiocarp, in fungi, is a large sporophore, or fruiting body, in which sexually produced spores are formed on the surface of club-shaped structures (basidia). Basidiocarps are found among the members of the phylum Basidiomycota. The tertiary mycelium is simply an organized mass of secondary mycelium. It is a morphologically complex tissue and forms structures such as the typically mushroom-shaped basidiocarps commonly seen in nature.

Q31. Any DNA molecule having foreign DNA is called:

• A. Mutant
• B. Recombinant✓
• C. Crossing over
• D. All of the above

Explanation: Recombinant DNA is the hybrid DNA made by two or more DNA molecules joined together. So B is the correct option.

Q32. Light absorbing pigments in photosystem I is:

• A. P 600
• B. P 680
• C. P 700✓
• D. P 760

Explanation: Photosystem I has chlorophyll a molecule which absorbs maximum light of 700 nm and is called P700, whereas reaction center of photosystem II has P680

Q33. In Eukaryotes, DNA replication proceeds at the rate of:

• A. 50 base pairs per seconds✓
• B. 40 base pairs per seconds
• C. 20 base pairs per seconds
• D. 30 base pairs per seconds

Explanation: DNA replicates at a rate of 50 nucleotides per second.

Q34. Fatty acids are:

• A. Linsaturated dicorboxylic acid
• B. Long chain alkanoic acid✓
• C. Aromatic carboxylic acid
• D. Aromatic dicarboxylic acid

Explanation: Alkanoic acids are alkane-derived organic compounds that contain the carboxylate (-COOH) functional group and fatty acids are carboxylic acids with long hydrocarbon chains.

Q35. Which of the following is an enzyme lacking disease?

• A. PKU✓
• B. Alkaptunuria
• C. Anuria
• D. Dluria

Explanation: Phenylketonuria occurs when parents pass the defective phenylalanine hydroxylase (PAH) gene that causes this disorder on to their children. This gene helps create the enzyme needed to convert phenylalanine to tyrosine. Phenylketonuria is a disorder of amino acid metabolism that occurs in infants born without the ability to normally break down an amino acid called phenylalanine. Phenylalanine, which is toxic to the brain, builds up in the blood.

Q36. Coelentrates have hydrostatic skeletion except:

• A. Coral✓
• B. Sea anemone
• C. Hydra
• D. Jelly fish

Explanation: Corals produce a hard exoskeleton formed of CaCO3 , it is secreted by epidermal cells that take lime from sea water.

Q37. Lungs are _ in srcin.

• A. Ectodermal
• B. Endodermal✓
• C. Mesodermal
• D. Preformed

Explanation: Endoderm cells give rise to certain organs, among them the colon, the stomach, the intestine, the lungs, the liver, and the pancreas. The ectoderm on the other hand eventually forms certain outer linings of the body.

Q38. The particular array of chromosomes that an individual possessed is called its:

• A. Genotype
• B. Phenotype
• C. Karyotype✓
• D. Genome

Explanation: "A karyotype is an individual's complete set of chromosomes. The term also refers to a laboratory-produced image of a person's chromosomes isolated from an individual cell and arranged in numerical order. A karyotype may be used to look for abnormalities in chromosome number or structure. Reference: Karyotype - National Human Genome Research Institute

Q39. Changes in gene frequencies in small population by chance is called:

• A. Gene pool
• B. Genetic drift✓
• C. Gene mutation
• D. Gene flow

Explanation: Genetic drift is a mechanism of evolution, it refers to random fluctuations in the frequencies of alleles from generation to generation due to chance of events, therefore the answer will be B.

Q40. Number of chromosomes in Tobacco is:

• A. 45
• B. 48✓
• C. 46
• D. 47

Explanation: Tobacco is an allopolyploid species (n=24 in a gamete) , hence the answer will be (2x24) that is B.

Q41. Urea formation occurs in:

• A. Kidney
• B. Liver✓
• C. Spleen
• D. Lungs

Explanation: b) Liver:This option states that urea formation occurs in the liver. This statement is correct. The liver is the primary site of urea formation in the body. It is an essential part of the process known as the urea cycle, where toxic ammonia (a byproduct of protein metabolism) is converted into urea, a less toxic compound. Urea is then transported to the kidney for excretion in urine.

Q42. Which is not correct about polyvinyl chloride?

• A. It is used in large scale production of cable insulator
• B. It is a copolymer✓
• C. It is a homopolymer
• D. It is used in the manufacturing of pipes

Explanation: b) It is a copolymer:This option states that polyvinyl chloride is a copolymer. This statement is not correct. PVC is not a copolymer; it is a homopolymer. A homopolymer is a type of polymer that is composed of repeating units of a single monomer. In the case of PVC, the repeating unit is vinyl chloride (CH2=CHCl).

Q43. Bone is surrounded by a membrane called:

• A. Perichondrium
• B. Prostomium
• C. Perimycium
• D. Periosteum✓

Explanation: The tough, thin outer membrane covering the bones is called periosteum.

Q44. Vernalization is the conversion of:

• A. Spring variety to the winter variety
• B. Winter variety to the spring variety✓
• C. Winter variety to the summer variety
• D. Summer variety to the winter variety

Explanation: The term vernalization originated from the Latin word Vernalis, which means “of the spring”. Vernalization is the artificial exposure of plants (or seeds) to low temperatures to stimulate flowering or enhance seed production. It is the conversion of the winter variety into the spring variety by low-temperature treatment. By satisfying the cold requirement of many temperate-zone plants, flowering can be induced to occur earlier than normal or in warm climates lacking the requisite seasonal chilling. Knowledge of this process has been used to eliminate the normal two-year growth cycle required of winter wheat. By partially germinating the seed and then chilling it to 0° C (32° F) until spring, it is possible to cause winter wheat to produce a crop in the same year.

Q45. A condition of excessive thirst due to diabetes is called:

• A. Polyuria
• B. Glycusuria
• C. Polyphagia
• D. Polydipsia✓

Explanation: Polydipsia is a medical name for the feeling of extreme thirstiness. Polydipsia is an early symptom of diabetes mellitus and diabetes insipidus. Diabetes mellitus causes polydipsia because your blood sugar levels get too high and make you feel thirsty, regardless of how much water you drink. Diabetes insipidus occurs when your body’s fluid levels are out of balance.

Q46. Implantation of zygote takes place in the:

• A. 2nd week✓
• B. 3rd week
• C. 7th week
• D. 5th week

Explanation: Implantation is the process of the blastocyst embedding into the endometrial lining of the uterus, which typically occurs in Week 2 of development. For implantation to occur, the blastocyst must completely hatch from the zona pellucida once the conceptus enters the uterine cavity

Q47. The smallest gametophyte is present in:

• A. Adiantum
• B. Funaria
• C. Marchantia
• D. Angiosperms✓

Explanation: Angiosperms, also called flowering plants, are about 300,000 species of flowering plants, the largest and most diverse group within the kingdom Plantae. The smallest and least complex gametophytes are those of flowering plants.

Q48. A protist that forms sea-weeds is:

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

Explanation: The brown algae comprise the class Phaeophyceae, golden-brown algae that range from small filamentous forms to large, complex seaweeds. These organisms are important as food and as habitat for many aquatic animals. Kelps (large brown seaweeds), for example, create a kelp forest that serves as a habitat for small marine animals.

Q49. Best known "Apicomplex" is the:

• A. Obligate parasites
• B. Facultative parasite
• C. Malarial parasites✓
• D. Pathogenic parasites

Explanation: Apicomplexan, also called sporozoan, are protozoan of the (typically) spore-producing phylum Apicomplexa. All apicomplexans are parasitic and lack contractile vacuoles and locomotor processes.Malaria is caused by a single-celled parasite of the genus Plasmodium. The malarial parasite, plasmodium, is the best-known apicomplexa. All Plasmodium species share a similar life cycle. It has two parts—in the first, the parasite infects a person (or a vertebrate host), and in the second, it is transmitted from the malaria patient (or infected vertebrate host) to another host by an insect vector.

Q50. Misuse of cannabis results in:

• A. Psychosis✓
• B. Euphoria
• C. Paranoia
• D. Photophobia

Explanation: Cannabis is a plant that has uses as a recreational and medicinal drug. Psychosis is a symptom that involves a disconnection from reality. When people experience psychosis, they may have symptoms such as delusions, hallucinations, and disordered thinking. Psychosis is one of the most common adverse effects due to the abuse of cannabis.

Q51. Outer wall of guard cells is:

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

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

Q52. The larva of balanoglossus (Hemichordate) is called:

• A. Bipinnaria
• B. Radiolaria
• C. Tornaria✓
• D. Trochophore

Explanation: Balanoglossus is a genus of ocean-dwelling acorn worms (Enteropneusta). Many hemichordates such as acorn worms have a larval stage in their life cycle; the larvae, called tornariae, swim using microscopic hairs called cilia. The tornaria larva resembles the bipinnaria larva of echinoderms.

Q53. The only human disease caused by VIROID is

• A. Hepatitis A
• B. Hepatitis B
• C. Hepatitis C
• D. Hepatitis D✓

Explanation: Viroids are infectious particles smaller than any of the known viruses, they cause numerous virulent plant diseases and are different in viruses due to their lack of the protein coat of a virus. The only human disease they cause is Hepatitis D (FACT).

Q54. Which of the following animal is included in deuterostome?

• A. Mytilus
• B. Chaetopterus
• C. Penguin✓
• D. Jelly fish

Explanation: Deuterostomes are organisms whose anus develops before the mouth in early embryonic development. Penguins are aquatic flightless birds that are categorized as Deuterostomes.

Q55. Heterospory occur in:

• A. Selaginella✓
• B. Equisetum
• C. Lycopodium
• D. Lepidodendron

Explanation: The phenomenon of the development of two types of spores (differing in size, structure, and function) by the same species is known as heterospory. Selaginella is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser club mosses. All species of Selaginella are heterosporous; that is, they produce spores of two sizes, the larger designated as megaspores and the smaller as microspores. The megaspores develop into female gametophytes and the microspores into male gametophytes.

Q56. The person is over weight of the body mass index is between:

• A. 15 to 24.9
• B. 17.5 to 24.9
• C. 18.5 to 24.9
• D. 25 to 29.9✓

Explanation: Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. It is a measure of whether you're a healthy weight for your height.For most adults, a BMI of:less than 18.5 means you’re underweight18.5 to 24.9 means you’re a healthy weight25 to 29.9 means you’re overweight30 to 39.9 means you’re obese40 or above means you’re severely obese

Q57. "Photo-phosph-rylation" is:

• A. ATP synthesis by food energy
• B. ATP synthesis by solar energy✓
• C. ATP synthesis by source of water
• D. ATP synthesis by source of NADH2

Explanation: It is the process of utilizing light energy to convert ADP to ATP.

Q58. Saponification of a fat:

• A. Always results in the formation of soaps.✓
• B. Results in the formation of esters.
• C. Results in the formation of waxes.
• D. Results in the formation glycerol and soap.

Explanation: Upon cooling of the dissolved mixture, solid soap was observed at the end of the process. Saponification is a process involving the hydrolysis of fats on its reaction with alkali, thereby leading to the formation of salts of fatty acids and glycerol. The salts of fatty acids are known as soap.

Q59. A special protein carrier in plasma membrane is:

• A. Catalase
• B. Lipase
• C. Permease✓
• D. Arginase

Explanation: Permease is a protein carrier found in the plasma membrane of cells. It assists in the transport of specific molecules across the membrane by facilitating their movement.

Q60. Phagocytosis, pinocytosis and autophagy are the functions of:

• A. Golgi-Apparatus
• B. Lysosomes✓
• C. Peroxisomes
• D. Glyoxisomes

Explanation: Lysosomes perform phagocytosis, pinocutosis and autophagy as they contain enzymes to digest foreign material and casue cell death.

Q61. Spiders belong to class:

• A. Crustacean
• B. Myriapoda
• C. Arachnida✓
• D. Hexapoda

Explanation: Spiders belong to the class of arachnida which is a class of joint legged invertebrate animals. Therefore the answer is C.

Q62. The gills are covered by operculum in

• A. Bony fishes✓
• B. Cartllaginous fishes
• C. Lung fishes
• D. Jawless fishes

Explanation: The operculum is a hard, plate-like bony flap that covers the gills of a bony fish protecting the gills and also serves a role in respiration. Hence the answer will be A.

Q63. Thalassaemia major is also known as:

• A. Sickle cell anemia
• B. Cooley‘s anemia✓
• C. Mycocystic anemia
• D. Nutritional anemia

Explanation: Thalassaemia major is also known as cooley's anemia.

Q64. The organs of excretion in crustacean are :

• A. Coxal glands✓
• B. Flame cells
• C. Malpighian tubules
• D. Nephridia

Explanation: Crustaceans are members of the subphylum Crustacea (phylum Arthropoda), a group of invertebrate animals consisting of some 45,000 species distributed worldwide. Coxal glands, in certain arthropods such as crustaceans, are a pair of excretory organs consisting of an end sac where initial urine is collected, a tubule where secretion and reabsorption may take place, and an excretory pore at the base (coxa) of one of the legs.

Q65. Sunken-stomata are found in the leaves of:

• A. Hydrophytes
• B. Xerophytes✓
• C. Mesophytes
• D. Glbberellins

Explanation: Xerophytes are plants that have adapted to life in a dry habitat (salt marsh, saline soil, or desert) by forming mechanisms to prevent water loss or to store available water. Examples of xerophytes are cacti, succulents etc. Sunken stomata are an example of those mechanisms, they prevent water loss and decrease transpiration.

Q66. Which of the following animals is not ectothermic?

• A. Salamander
• B. Great white shark
• C. Polar bear✓
• D. Butterfly

Explanation: Polar bears are endothermic animals. Endotherms, so-called warm-blooded animals, are those that maintain a constant body temperature independent of the environment. The endotherms primarily include birds and mammals; however, some fish are also endothermic.

Q67. Embryonic mass can generate all of the following except:

• A. Amnion
• B. Chorion✓
• C. Yolk sac
• D. Allantois

Explanation: The embryonic mass is the mass of cells inside the embryo that will eventually give rise to the definitive structures of the fetus. It cannot generate the chorion, which forms the placenta.

Q68. A hormone that prevents senescence In leaves is:

• A. Abscisic acid
• B. Cytokinin✓
• C. Seisomonasty
• D. Demonasty

Explanation: Senescence is the aging of individual cells within an organism. The organism itself is still alive and metabolizing energy, but its cells no longer divide to create new cells, which is necessary for growth and repair. Hence, the individual cells remain alive but in a state of dormancy. Cytokinins are plant hormones that influence growth and the stimulation of cell division. Cytokinins also act in conjunction with auxin (another plant hormone) to retard senescence. During leaf senescence, cytokinins reduce sugar accumulation, increase chlorophyll synthesis, and prolong the leaf photosynthetic period.

Q69. The chloroplast size is about.

• A. 1-2 µm
• B. 2-4 µm
• C. 4-6 µm✓
• D. 6-8 µm

Explanation: Chloroplasts are a type of plastid. They are chlorophyll-containing organelles within the cells of plants and green algae that are the site of photosynthesis, the process by which light energy is converted to chemical energy, resulting in the production of oxygen and energy-rich organic compounds. They are enclosed in a chloroplast envelope, which consists of a double membrane with outer and inner layers, between which is a gap called the intermembrane space. Chloroplasts have a diameter of about 4 - 6 micrometers.

Q70. The blood flow in milliliters/ minute during exercise to the skin is:

• A. 1500 ml
• B. 1600 ml
• C. 1800 ml
• D. 1900 ml✓

Explanation: Skin blood flow plays a major role in the distribution of thermal energy during exercise. When we exercise, our body temperature increases and carries the blood toward the skin’s surface, causing us to sweat and cool off. This natural body mechanism can lead to a flushed, red face, which can be especially more noticeable in fair-skinned individuals. The blood flow to the skin during exercise is 1900 ml/min. orMore oxygen is required by the cells as the rate of respiration increases, thus the blood flow to the skin increases as well.REFERENCE: KPK BIOLOGY BOOK

Q71. The enlarged lining epithelium cells connected with groups of developing spermatozoa in testes is:

• A. Somatic cells
• B. Sertoli cells✓
• C. Stem cells
• D. Totipotent cells

Explanation: Sertoli cells are the epithelial supporting cells of the seminiferous tubules. They are derived from the epithelial sex cords of the developing gonads.

Q72. Which of the following play role in Biorhythm?

• A. MSH
• B. LH
• C. ADH
• D. Melatonin✓

Explanation: Melatonin is a hormone involved in many biological and physiological regulations in the body. It is an effective hormone for human biorhythm (circadian rhythm) as the main role of this hormone is to maintain the biological clock and to adjust the body rhythm.

Q73. Hypothalamus is a part of:

• A. Diencephalon✓
• B. Myelencephalon
• C. Telencephalon
• D. Metencephalon

Explanation: The hypothalamus is a region of the forebrain located below the thalamus, forming the basal portion of the diencephalon.

Q74. Accessory pigments are:

• A. Red-Yellow-Green
• B. Red-Orange-Blue
• C. Orange-Blue-Green
• D. Red-Orange-Yellow✓

Explanation: Accessory Pigments are the source of much of the RED-ORANGE-YELLOW coloration that we see in plant leaves.

Q75. The product of light dependent reactions are:

• A. RUBP + ATP
• B. RUBP + PGAL
• C. NADPH + ATP✓
• D. PGAL + ATP

Explanation: The two products of light dependent reaction of photosystem are ATP and NADPH. The light reaction is the first stage of the photosynthesis process in which solar energy is converted into chemical energy in the form of ATP and NADPH. The three products of the light reaction of photosynthesis are ATP, NADPH, and O2.

Q76. Chlorophyll is protected from intense light by:

• A. Phytochrome
• B. Phytokinin
• C. Phytocyanin
• D. Carotenoids✓

Explanation: Some carotenoids protect chlorophyll from intense light by absorbing and dissipating excessive light energy, rather than transferring energy to chlorophyll.

Q77. Human arm is homologous with:

• A. Sea flipper
• B. Octopus Tntade
• C. Bird wing
• D. Both A and C✓

Explanation: Anatomically, the human arm, the flippers of seals, and the wings of the birds are the forelimbs containing similar bones. These forelimbs have a common origin and similar anatomical features but have been modified to perform different functions. Flippers allow the seal to swim, birds fly using their wings and humans perform a variety of functions using the arms. Such structures are homologous to each other.

Q78. A specific nudeotide sequence on DNA molecule to which RNA polymerase attaches to initiate transcription of mRNA from a gene is called:

• A. Poly genes
• B. Genome
• C. Promoter✓
• D. Pletoropy

Explanation: The first step in transcription is initiation, when the RNA pol binds to the DNA upstream (5′) of the gene at a specialized sequence called a promoter.

Q79. The bone dissolving cells are called:

• A. Osteoclast✓
• B. Osteoblasts
• C. Osteocytes
• D. Fibroblast

Explanation: Bone-dissolving cells called osteoclasts are derived from a type of immune cells called macrophages. They are necessary for the maintenance and renewal of bones.Osteoclasts are specialized cells found in bone tissue and are a crucial component of the skeletal system. They are responsible for bone resorption, which is the process of breaking down and removing old or damaged bone tissue. Osteoclasts are large, multinucleated cells derived from monocytes, a type of white blood cell. They are primarily located on the surface of bone and contain specialized structures called ruffled borders, which directly interact with the bone surface. When bones need to be remodeled or repaired, or when calcium needs to be released into the bloodstream, osteoclasts are activated. They secrete enzymes and acids that dissolve the mineralized matrix of the bone, breaking it down into its constituent minerals and collagen fibers. This process creates small cavities known as resorption pits. After osteoclasts have completed their work, osteoblasts, another type of bone cell, come in and begin the process of bone formation, filling in the resorption pits with new bone tissue. This dynamic balance between osteoclasts and osteoblasts is essential for maintaining bone health, density, and strength throughout a person's life. Any disruption in this balance can lead to conditions like osteoporosis, where bone resorption outpaces bone formation, resulting in weaker and more brittle bones.

Q80. Appendix is vestigial in man but may play role in:

• A. Digestion
• B. Excretion
• C. Immunity✓
• D. Movement

Explanation: The appendix has been found to play a role in mammalian mucosal immune function. It is believed to be involved in extrathymically derived T-lymphocytes and B-lymphocyte mediated immune responses and is also said to produce early defenses that help prevent serious infections in humans. Therefore the answer is C.

Q81. The birds excrete:

• A. Ammonia
• B. Urea
• C. Uric acid✓
• D. Acetic acid

Explanation: Nitrogenous waste is excreted in the form of uric acid in birds.

Q82. Microvilli are also called:

• A. Leaf veins
• B. Cristae✓
• C. Capillaries
• D. Leaf midribs

Explanation: Microvilli, also known as a brush border for their appearance, are mostly found in the small intestine. They are also called 'cristae'

Q83. Stroma of chloroplasts carries the fixation of

• A. N2
• B. O2
• C. CO2✓
• D. NH3

Explanation: The stroma contains the necessary enzymes for carbon fixation.

Q84. Which one of the following is a sex-linked inheritance?

• A. Baldness✓
• B. Albinism
• C. Eye colour
• D. Myopia

Explanation: Males with higher testosterone levels have a dominant baldness gene, whereas females with lower testosterone levels have a recessive baldness gene. So baldness has sex linked inheritance.

Q85. The valve between left ventricle and aorta is called:

• A. Semi lunar valve✓
• B. Blcuspid valve
• C. Tricuspid valve
• D. Pulmonary valve

Explanation: The term semilunar refers to the aortic valve and the pulmonary valve, tricuspid is the valve between the right atrium and ventricular and bicuspid between left atrium and ventricular. Hence the answer will be A.

Q86. Select mineral that is considered as a macronutrient.

• A. Phosphorus✓
• B. Zinc
• C. Iron
• D. Iodine

Explanation: Calcium, sodium, magnesium, phosphorus and potassium are sometimes included as macronutrients because they are required in relatively large quantities compared with other vitamins and minerals.

Q87. Which of the following ions can act both as bronsted acid and base in solvent water

• A. CN–
• B. SO4 –2
• C. CHO3-
• D. PO4-3✓

Explanation: Phosphate ions act as Bronsted-Lowry acids or bases depending on the situation. With O- in water, H2PO4- will act as an acid, whereas with HBr, it will act as a base

Q88. Molar extinction coefficient (ε) a constant in Beer- Lambert law is the characteristics of the:

• A. Solute
• B. Solvent
• C. Concentration
• D. All of the above✓

Explanation: Under defined conditions of solvent, pH, and temperature the molar absorption coefficient for a particular compound is a constant at the specified wavelength. Furthermore, it is used to calculate concentration using A = εLcWhere A is the amount of light absorbed by the sample for a particular wavelength,ε is the molar extinction coefficient, L is the distance that the light travels through the solution, and c is the concentration of the absorbing species per unit volume. Hence, it is a characteristic of concentration, as well as solute, and solvent.

Q89. The energy difference between adjacent energy levels of the hydrogen atom:

• A. Increases with increasing energy
• B. Decreases with increasing energy✓
• C. First increases and then decreases with increasing energy
• D. First decreases and then increases with increasing energy

Explanation: As energy levels increase, the energy difference between adjacent ones decreases due to the trend of decreasing energy from the energy equation for each Bohr orbit for hydrogen-like species

Q90. Choose reactants whose reaction product is ester:

• A. CH3COOH and CH3OCH3
• B. CH3COOH and C2H5OH✓
• C. CH3COOH and CH3CHO
• D. CH3COOH and CH3COCH3

Explanation: When primary alcohol is treated with a carboxylic acid in the presence of sulphuric acid a compound is formed. This compound has a sweet smell. The compound obtained is called an ester. The chemical reaction occurring in the formation of the ester is known as an esterification reaction.

Q91. Choose the IUPAC name of the following compound: CH3 | CH3 — CH — CH2 — CH = CH2

• A. 4- Methyl-1-Pentene✓
• B. 2- Methyl-3- Pentene
• C. 2- Methyl-2- Pentene
• D. 4,4-Dirnethyl-2-Pentene

Explanation: According to the IUPAC system of naming compounds, the methyl group is the substituent that will have secondary importance because there is a double bond which is of primary importance that is why we'll give the double bond the smallest carbon number possible which is carbon 1 from the left side.Iupac for naming alkene: The longest carbon chain containing the carbon-carbon double bond is selected as the parent alkene. The suffix 'ane' of the alkane is replaced by 'ene'. If a double bond occurs twice or thrice in the parent chain the alkene is called diene or triene respectively. All the other options are incorrect according to the IUPAC nomenclature.

Q92. Which is the strongest acid?

• A. CH3COOH
• B. CH2CICOOH
• C. CHCl2COOH
• D. CCl3COOH✓

Explanation: An electron-withdrawing group increases the acidity of carboxylic acid. It disperses negative charge by inductive/ resonance effect and stabilizes the carboxylate ion. An electron-withdrawing group draws electrons away from a reaction center. When this center is an electron-rich carbanion or an alkoxide anion, the presence of the electron-withdrawing substituent has a stabilizing effect. Examples of electron-withdrawing groups are. · halogens (F, Cl).This acid has the shortest carbon chain and the most chlorine atoms which are more electron-withdrawing than hydrogen hence making the molecule more acidic.

Q93. Choose the type of hybridization of carbon atoms in cyclopropane and the bond angle C–C–C.

• A. Sp3, 109.5*
• B. Sp3, 60*✓
• C. Sp2, 120*
• D. Sp2, 107*

Explanation: Cyclopropane has carbons with four bonds, hence they are SP3, but with bond distances less than normal alkanes and C-C-C bond angles of 60 degrees and H-C-H angles of 120 degrees. They are a special case as usually SP3 hybridization displays 109.5-degree angles

Q94. Hemiacetal containing both

• A. Alcohol and aldehyde functional groups
• B. Alcohol and ether functional groups✓
• C. Aldehyde and ether functional groups
• D. Alcohol and carboxylic acid functional groups

Explanation: Hemiacetal is a molecule made up of a core carbon atom connected to four groups: –OR, –OH, –R, and –H. Acetal is a molecule made of a core carbon atom that is attached to two –OR groups, a –R group, and a –H group. RHC(OH)OR' is the general formula for a hemiacetal.orHemiacetals are formed from the combination of alcohols and aldehydes and display at least one hydroxyl group from the alcohol and have an ether functional group with oxygen connecting 2 carbons

Q95. Carbylamine test is given by:

• A. Primary amines✓
• B. Secondary amines
• C. Tertiary amines
• D. All of these

Explanation: Only primary amines give the carbylamine test. Hoffmann's carbylamine test/ Isocyanide test: Aliphatic or aromatic primary amines on heating with chloroform and alcoholic KOH give foul smelling alkyl isocyanides or carbylamines. This test is not given by secondary or tertiary amines.

Q96. Which of the following compounds does not give iodoform test on reaction with I2 and NaOH?

• A. Propanone
• B. Ethanol
• C. Butanone
• D. 2-Propanol✓

Explanation: Compounds containing either CH3C∣HOH or CH3C∣=O group, on reaction with NaOH and I2 form yellow coloured iodoform. This is called the iodoform test.

Q97. Which of the following substitutents is an Ortho and Para director and ring deactivating?

• A. –OH
• B. –NH2
• C. –Cl✓
• D. –OCH3

Explanation: The substituents which are deactivating but ortho para directing in aromatic substitutions are -NO , -CHO, -F , -Cl, -Br , -CH = CHCHO, - C6H5, - COCl, -NH3

Q98. Which of the following compounds undergo nitration most readily?

• A. Benzene
• B. Toluene✓
• C. Benzoic acid
• D. Nitrobenzene

Explanation: Toluene undergoes nitration about 25 times faster than benzene.The methyl group in toluene is an activating group. It increases the electron density in ortho and para positions and hence, an electrophile readily attacks the position. The presence of an ortho para directing group increases the rate of reaction, Hence, nitration of toluene is faster than benzene.

Q99. N2(g) + 3H2 (g) ------> 2NH3(g), △H= 46.1 kj/mole For the reaction above which statement is true about the equilibrium constant (Keq):

• A. Keq Increases with increase in temperature✓
• B. Keq decreases with increase in temperature
• C. Keq decreases with ncrease in pressure
• D. Keq increases with decrease in pressure

Explanation: The value of △H is positive which means the reaction is endothermic and heat is absorbed. So if we increase the temperature, the equilibrium will favour the right hand side i.e more products will be formed.

Q100. Which of following functional groups are deactivating and not ortho, para directing?

• A. –R
• B. –COR✓
• C. –NH2
• D. NR2

Explanation: Ortho and para directing grps release electrons to the benzene ring increasing the chemical reactivity of the benzene ring towards electrophiles. Meanwhile meta directing grps withdraw the electrons from the benzene ring towards themselves decreasing their availability towards electrophiles. Therefore the answer will be B.

Q101. Primary amines on treatment with alkyl halide yield;

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

Explanation: Primary amines on treatment with alkyl halide yield a mixture of secondary amine, tertiary amine, and quaternary ammonium salt. The reaction is a nucleophilic substitution reaction, in which the nitrogen atom of the amine attacks the halogen atom of the alkyl halide. The reaction can be represented by the following equation: RNH2 + R'X → RNHR' + HX In the first step of the reaction, the nitrogen atom of the amine donates a pair of electrons to the halogen atom of the alkyl halide. This forms a new bond between the nitrogen atom and the alkyl group, and it also releases the halide ion. The halide ion is then removed from the solution. In the second step of the reaction, the nitrogen atom of the amine can react with another molecule of alkyl halide. This forms a new bond between the nitrogen atom and the second alkyl group, and it also releases another halide ion. The halide ion is then removed from the solution. The reaction can continue in this way to form a tertiary amine or a quaternary ammonium salt. The exact product that is formed depends on the concentration of the amine and the alkyl halide. The reaction of primary amines with alkyl halides is a very important reaction in organic chemistry. It is used to synthesize a variety of secondary, tertiary, and quaternary amines. The reaction is also used to make drugs, dyes, and other organic compounds.

Q102. Choose group that cause solubility of the dye in acids.

• A. –OH
• B. –NH2✓
• C. –SO2H
• D. –COOH

Explanation: Amines are used in making azo dyes and nylon apart from medicines and drugs. They are widely used in developing chemicals for crop protection, medication, and water purification. They also find use in products of personal care. Ethanol amines are the most common type of amine used in the global market.

Q103. What is the number of hydrogen atoms in 5 moles of water?

• A. 3.0115 × 1024
• B. 6.023 × 1024✓
• C. 6.023 x 1023
• D. 5.0 x 1023

Explanation: 5 moles of water contains 5 moles of H2, therefore contains 10 moles of H atoms. The number of atoms in one mole of a substance is given by Avogadro's constant, which is 6.02x1023. Thus the number of hydrogen atoms in 5 moles of water = 10x(6.02x1023) = 6.02x1024 H atoms.

Q104. In themain postulates of Bohr atomic theory the angular momentum of electron in hydrogen atom is given by the relationship.

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

Explanation: Angular momentum of an electron by Bohr is given by mvr or nh/2π (where v is the velocity, n is the orbit in which electron is, m is mass of the electron, and r is the radius of the nth orbit).

Q105. The reduction of aldehydes and ketones in the presence of zinc amalgam and HCl is termed as:

• A. Grignard reduction
• B. Clemmenson reduction✓
• C. Wolf-kishner reduction
• D. Friedel-craft reduction

Explanation: The Clemmensen reduction is a reaction that is used to reduce aldehydes or ketones to alkanes using hydrochloric acid and zinc amalgam. The Clemmensen reduction is named after a Danish chemist, Erik Christian Clemmensen.

Q106. Aiman in laboratory dissolve 4g of NaOH in 250ml of water. The molarity of this solution is:

• A. 0.4M✓
• B. 4M
• C. 0.2M
• D. 0.1M

Explanation: M = 4/40 / 250/1000 = 0.4, where 4g is the amount of NaOH, 40 is the grams per mole of NaOH, 250mL is the amount of water and 1000 is the number of ml in a liter. The most common way to express solution concentration is molarity (M), which is defined as the amount of solute in moles divided by the volume of solution in liters: M = moles of solute/liters of solution.

Q107. Which of the following is not a ferromagnetic substance?

• A. Iron
• B. Cobalt
• C. Nickel
• D. Barium✓

Explanation: Nickel is one of only four metals that are ferromagnetic, meaning they are attracted to magnets and are magnetic themselves. The others are iron, cobalt and gadolinium.

Q108. Milk sugar is pasteurized by heating for 15 seconds at the temperature of:

• A. 60 oC
• B. 71 oC✓
• C. 50 oC
• D. 80 oC

Explanation: Pasteurization of milk, requires temperatures of about 63 °C (145 °F) maintained for 30 minutes or, alternatively, heating to a higher temperature, 72 °C (162 °F), and holding for 15 seconds.

Q109. Which one of the following is most ionic?

• A. NaCl
• B. MgCl2
• C. KCl✓
• D. AlCl3

Explanation: Both KCl and NaCl has one valence electron but since K has larger size than Na therefore it will be easy to remove electron from K then from Na. Moreover according to Fajan rule the ion with low charge denstiy and greater size will form ionic bond and that is the case with KCl in the given opt

Q110. The compound used in borax bead test for the detection of basic redicals to form colored bead is:

• A. H2BO2
• B. (C2H5)3BO3
• C. Ca2B6O115H2O
• D. Na2B4O710H2O✓

Explanation: Per one molecule of borax, there are 10 molecules of water of crystallization. Hence, metaborate is formed in the borax bead test.

Q111. Milk of magnesia is used for treatment of acidity in stomach, its formula is:

• A. Mg(OH)2✓
• B. MgSO4
• C. Ca(OH)2
• D. CaSO4

Explanation: Milk of magnesia, also known as magnesium di-hydroxide or magnesium hydroxide, is a chemical compound with the formula Mg(OH)2.

Q112. Which of the following ions play important role in the transportation of carbon dioxide?

• A. Sodium
• B. Potassium
• C. Bicarbonate✓
• D. Chloride

Explanation: The majority of carbon dioxide is transported as bicarbonate ions. This is because erythrocytes have a high activity of carbonic anhydrase, an enzyme that catalyzes the reaction between carbon dioxide and water.

Q113. Which of the following compound is assigned the octane number of 100?

• A. n-heptane
• B. n-octane
• C. 2,3,3-trimethyl pentane (D) 2,2,4-trimethyl
• D. 2,2,4-trimethyl pentane✓

Explanation: Isooctane (2,2,4-trimethyl pentane ) exhibits excellent knock resistance and thus is assigned a value of 100.

Q114. The major product of acid catalysed dehydration of 3- pentanol is:

• A. 1-pentane
• B. 3-Pentene✓
• C. 2-Methyle butane
• D. 3-Methyle butane

Explanation: Explanation is given below.

Q115. Which of the following compound will react most readily with bromine in CCl4?

• A. 1-pentane
• B. 2-pentane
• C. 2-Methyle-1- butane✓
• D. 3-Methyle-1- butane

Explanation: Which is 2-Methyl-1-butene NOT 2-Methyl-1-butane Halogen addition is electrophilic addition and increasing order of reactivity towards halogen addition is Alkane < Alkyne < Alkene Alkynes are less reactive than alkene towards addition of halogen, the intermediate formed in case of alkyne is less stable. In alkenes, more substituted alkeness are reactive towards Br2/Cl2. "2-methyl-1-butane" is a hydrocarbon compound with the molecular formula C7H16. It is an example of an alkane, which is a type of hydrocarbon with only single bonds between carbon atoms. When you mention "in CCl4," I assume you're referring to the compound being dissolved or present in carbon tetrachloride (CCl4), which is a nonpolar solvent commonly used in organic chemistry. In a solution of "2-methyl-1-butane in CCl4," the hydrocarbon will dissolve and mix with the carbon tetrachloride. Since both compounds are nonpolar in nature, they will be compatible and form a homogeneous mixture. Carbon tetrachloride is often used as a solvent in NMR (nuclear magnetic resonance) spectroscopy to dissolve organic compounds for analysis. Keep in mind that "2-methyl-1-butane" refers to a specific arrangement of carbon atoms in the hydrocarbon molecule, where there is a methyl (CH3) group attached to the second carbon atom in the chain, and the longest continuous carbon chain contains four carbon atoms. The compound is also known by the name "isohexane."

Q116. Select the strongest acid The pKa values are given:

• A. HI, pKa=10
• B. HCN, pKa=9.4
• C. H2SO4, pKa = 1.8✓
• D. HNO3, pKa = 3.0

Explanation: Simply pKa value indicates how easily the acid loses a proton. If pKa value is high, then the acid is weak while pKa value low means the stronger acid. pKa value indicates the strength of the acid.

Q117. The smaller the value of pKb:

• A. The weaker the base
• B. The stronger the base✓
• C. The stronger the acid
• D. None of the above

Explanation: Pkb is a negative base-10 logarithm of the base dissociation constant kb of a solution, it is used to determine the strength of a base/alkaline solution,the smaller the value of pkb the stronger the base, therefore the answer is B.

Q118. In which of the following pairs are both substances normally crystalline?

• A. Copper and diamond✓
• B. Copper and glass
• C. Copper and rubber
• D. Diamond and glass

Explanation: Diamond is a crystal that is transparent to opaque and generally isotropic, native copper is a polycrystal. Therefore the answer will be A.

Q119. Which one of the following is strongest acid?

• A. CH3COOH
• B. CH3 CH2 COOH
• C. C6H5CG2COOH
• D. FCH2COOH✓

Explanation: D is the correct optionas it contains a halogen which have strong electron withdrawing effects.

Q120. The total energy of a hydrogen atom in its ground state is:

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

Explanation: The total energy of a hydrogen atom in its ground state can be calculated using the Schrödinger equation, which is a fundamental equation in quantum mechanics. The ground state of a hydrogen atom refers to the lowest energy state that the electron can occupy. In the Bohr model of the hydrogen atom, the ground state energy can be expressed as: E = -13.6 eV / n2 Where: E is the energy of the ground state in electron volts (eV), n is the principal quantum number, which is equal to 1 for the ground state. Plugging in the values: E = -13.6 eV / (12) = -13.6 eV So, the total energy of a hydrogen atom in its ground state is approximately -13.6 electron volts.

Q121. For all adiabatic processes:

• A. The entropy of the system does not change
• B. The entropy of the system increases
• C. The entropy of the system decreases
• D. The entropy of the system does not decrease✓

Explanation: Essential conditions for the adiabatic process to take place are: i) System is perfectly insulated from surrounding. ii) The process must be carried out rapidly so that the system has sufficient time to exchange heat with the surroundings. Adiabatic processes are characterized by an increase in entropy, or degree of disorder, if they are irreversible and by no change in entropy if they are reversible. Adiabatic processes cannot decrease entropy.

Q122. Phosphodiester linkage is formed between.

• A. Two nucleotide bases
• B. Amino acid
• C. Two sugar
• D. Nucleotides and phosphates✓

Explanation: In the polynucleotide, adjacent nucleotides are joined by a phosphodiester linkage, which consists of a phosphate group that links the sugars of two nucleotides. This bonding results in a repeating pattern of sugar-phosphate units called the sugar-phosphate backbone. (Note that the nitrogenous bases are not part of the backbone.) Complementary nitrogenous bases are held together by hydrogen bonds.

Q123. The shape of SnCl2 is:

• A. Linear
• B. Tetrahedral
• C. Angular✓
• D. Trigonal Planar

Explanation: SnCl2 (Tin dichloride) has a bent or V-shaped geometry, which is an example of an angular or non-linear shape. The molecule has a central tin atom that is bonded to two chlorine atoms. The two bond pairs of electrons repel each other, resulting in a bent shape. The bond angle is approximately 119 degrees. This bent shape is due to the lone pair of electrons present on the tin atom. The lone pair occupies a greater amount of space compared to the bond pair, resulting in the distortion of the molecule. In contrast, the linear shape is a molecular geometry in which the atoms of the molecule are arranged in a straight line, like in HCl or CO2. Tetrahedral shape is a molecular geometry that has four atoms attached to a central atom, like in CH4 or CCl4. Trigonal shape is a molecular geometry that has three atoms attached to a central atom, like in BF3.

Q124. Which is not true about Grignard reagent?

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

Explanation: The statement that is not true about Grignard reagents is They are very stable compounds and can be isolated easily. Grignard reagents are highly reactive compounds and must be handled with care. They are typically prepared in situ, just before they are used, and they cannot be isolated.

Q125. Select the true statement about the amorphous solids:

• A. Amorphous substances have a sharp melting point
• B. Amorphous substances do not have fixed a melting point✓
• C. Amorphous substances have proper geometrical shapes
• D. The particles in amorphous substances are arranged in an orderly manner

Explanation: An amorphous solid does not have a sharp melting point but melts over a range of temperatures. For example, glass on heating first softens and then melts over a temperature range.

Q126. Both NaNO3 an CaCO3 crystallize in Rhombohedral forms therefore they are:

• A. Allotropes
• B. Polymorphous
• C. Isomorphous✓
• D. None of these

Explanation: Two or more substances having the same crystal structure called isomorphous.

Q127. Pure water freezes at 0 oC and boils at 100 oC at standard conditions. Calcium chloride was added to pure water. What do you expect about its freezing point and boiling point?

• A. No change in its freezing point and boiling point
• B. Freezing point increases and boiling point decreases.
• C. Freezing point increases and boiling point increases
• D. Freezing point decreases and boiling point increases✓

Explanation: The presence of impurities in a substance lowers the melting point but increases the boiling point of the substance.

Q128. Equal volume of different gases under same condition of temperature and pressure contain the same number of particles. The above statement is of:

• A. Avogadro‘s law✓
• B. Graham‘s Law
• C. Dalton‘s law
• D. Hund‘s rule

Explanation: Avogadro's law states that under the same conditions of temperature and pressure, equal volumes of different gases contain an equal number of molecules.

Q129. Sodium chloride crystal structure is:

• A. Hexagonal
• B. Body centered cubic
• C. Face centered cubic✓
• D. Tetragonal

Explanation: Explanation diagram is given below.

Q130. An acid is a substance which accepts:

• A. An electron pair✓
• B. Proton
• C. An electron
• D. Pair of proton

Explanation: By Bronsted-Lowery concecpt an acid is a substance which lose a proton. By Lewis concept an acid is a substance which accepts An electron pair.

Q131. Choose the compound in which hydrogen bonding is not possible:

• A. H2O
• B. HCl4
• C. CH3COOH
• D. CH3OCH3✓

Explanation: Due to the presence of methyl groups that bounds to oxygen there is less tendency of hydrogen bonding in ethers.Also, it does not have hydrogen attached to oxygen, so it cannot form hydrogen bonds with itself. The carboxylic acid, alcohol and water being polar show H-bonding. Option A is correct.

Q132. Which one of the following does not exist?

• A. HBO2
• B. HFO2
• C. H3PO3
• D. HBrO2✓

Explanation: HBrO2(aq) is bromous acid and HIO2(aq) is iodous acid. Like many of the oxyacids, the molecules of HBrO2 (hydrogen bromite) and HIO2 (hydrogen iodide) are unlikely to exist in nature as they would likely decompose into oxides and water vapour when trying to isolate them from their respective acid solutions.

Q133. Which of the following is not a nucleophile?

• A. NH3
• B. HO
• C. HC = CH
• D. Br2✓

Explanation: The electron rich part of the double bond causes a dipole to form meaning that bromine becomes electron deficient and therefore becomes the electrophile (hence electrophillic addition) hence the answer is D. Rest of the options are incorrect as they have lone pair of electrons or an electron rich double bond (in case of alkenes) which makes them nucleophiles.

Q134. To distinguish among primary, secondary and tertiary alcohols which of the following tests is used?

• A. Benedicts reagent
• B. Tollen‘s reagent
• C. Lucas test✓
• D. None of the above

Explanation: The lucas test is used to differentiate between primary, secondary and tertiary alcohols,an oily layer of alkyl halides separates out in these reactions. With the oily layer being formed immediately in tertiary alcohols, in 5 - 10mins in secondary and only on heating in primary. Therefore the answer is C.

Q135. Which one of the following compound participates in hydrogen bonding?

• A. CH3
• B. CH3 OCH3
• C. CH3NH3✓
• D. C6 H5 OCH3

Explanation: Hydrogen bonding is possible when a hydrogen atom is bonded to another electronegative atom like O,F,N etc therefore the answer will be C.

Q136. The bond angle between H-C-H bond in ethane is:

• A. 109.5✓
• B. 120
• C. 90
• D. 107.5

Explanation: Ethane, C2H6, has a geometry related to that of methane. The two carbons are bonded together, and each is bonded to three hydrogens. Each H-C-H angle is 109.5° and each H-C-C angle is 109.5°.

Q137. Conc. HCI is added to a metal salt and then subjected to flame test on platinum wire. It Imparts crimson color to the flame. Which metal salt it is?

• A. Sodium
• B. Potassium
• C. Strontium✓
• D. Calcium

Explanation: Strontium displays a red flame when it undergoes the flame test with acid and platinum wire

Q138. Which of the following misnamed?

• A. Aniline
• B. Methyl naphthalene
• C. Carboxyl benzene✓
• D. Benzene sulphonic acid

Explanation: When a carboxyl group is added to a Benzene ring, it is called Benzoic acid.Thus Option C is the right answer.

Q139. Which of the following structure has a bond formed by an overlap of sp2 hybrid orbital with that of sp2 hybrid orbital?

• A. HC = CH
• B. H2C = CH2✓
• C. H2C = C= CH2
• D. CH2 = CHCH3

Explanation: The C-C sigma bond in ethylene is formed by the overlap of an sp2 hybrid orbital from each carbon. The overlap of hybrid orbitals or a hybrid orbital and a 1s orbtial from hydrogen creates the sigma bond framework of the ethylene molecule.

Q140. What are the units of the ratio: specific latent heat of vaporization of water/ specific heat capacity of water

• A. K✓
• B. 1/K
• C. K^2
• D. no unit

Explanation: Explanation

Q141. Moon is revolving around the earth, work done by the earth on the moon is

• A. positive
• B. zero✓
• C. negative
• D. none of these

Explanation: B. The formula for work done on a body is; W = F × d cos θWhere,F = the force of gravitation applied by the earth.d = displacement between the two bodiesθ = the angle between F and dWhen the moon revolves around the earth, there is a 90° angle between the displacement of the moon and the gravitational force exerted by the earth.Putting θ = 90° in the equation,W = F × d cos But, Cos 90° = 0So, W = 0

Q142. Can we see magnetic flux lines?

• A. Yes
• B. No✓
• C. Depends on strength of field
• D. Only when the field is large

Explanation: Magnetic flux lines are imaginary lines drawn solely for a better understanding of magnetic flux.

Q143. Spectral lines is like a _ of absorbed or emission energy in a spectrum

• A. charged pattern
• B. fingerprint pattern✓
• C. discharged pattern
• D. None of these

Explanation: Fingerprints are patterns specific to each person, therefore they can be used to identify individuals. Similarly, spectral lines act as fingerprints that allow us to identify and distinguish the matter within galaxies and heavenly bodies. By studying the light emitted from certain celestial bodies, spectral lines tell us about the presence of certain atoms and elements present within that body.

Q144. Michelson interferometer can be used to measure:

• A. speed of sound
• B. wavelength of sound
• C. speed of light
• D. wavelength of light✓

Explanation: Michelson's Interferometer uses the phenomena of interference to measure the wavelength of light from a source.

Q145. In stationary waves:

• A. There is not transfer of energy
• B. Energy is constant at all points
• C. Phase is the same for all points
• D. Both (a) & (b)✓

Explanation: In a stationary wave, there is no net transfer of energy. This is because the energy is alternately transferred from one point to another, but it does not travel in any particular direction. The energy is also constant at all points in a stationary wave. This is because the energy is evenly distributed between the two waves that are interfering to create the stationary wave.

Q146. If each vector have unit magnitude than ⃗A. ⃗A is:

• A. South
• B. One✓
• C. North
• D. West

Explanation: The answer is one. The dot product of two vectors is a scalar quantity that represents the product of the magnitudes of the two vectors and the cosine of the angle between them. If each vector has a unit magnitude and the angle between them is 0 degrees, then the dot product is equal to one. Here is the formula for the dot product of two vectors: A⃗.B⃗=|A⃗||B⃗|cosθ where: A⃗ and B⃗ are the two vectors |A⃗| and |B⃗| are the magnitudes of the two vectors θ is the angle between the two vectors If each vector has a unit magnitude, then |A⃗| = |B⃗| = 1. If the angle between the two vectors is 0 degrees, then cosθ = 1. Therefore, the dot product is equal to 1.

Q147. In a purely resistive circuit the current:

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

Explanation: The answer is (d), is in phase with the voltage. In a purely resistive circuit, the current and voltage are in phase with each other. This means that the current reaches its peak at the same time as the voltage, and the current troughs at the same time as the voltage troughs. The reason for this is that the resistance in a purely resistive circuit does not cause any phase shift between the current and voltage. The resistance simply converts the electrical energy from the voltage source into heat energy.

Q148. The number of ejected photoelectrons increases with increase.

• A. In intensity of flight✓
• B. In wavelength of light
• C. In frequency of light
• D. Never

Explanation: The number of ejected photoelectrons increases with an increase in the intensity of light. This phenomenon is explained by the photoelectric effect, where photons of light (quanta of electromagnetic energy) interact with a material, causing the ejection of electrons from the material's surface. The intensity of light refers to the number of photons striking the material per unit area per unit time. When the intensity of light increases, more photons are incident on the material, leading to a greater number of photoelectrons being emitted.

Q149. Which is strong electrolyte?

• A. Ca(OH)2
• B. SiCI4
• C. KCl✓
• D. SrCl2

Explanation: KCl is a strong electrolyte. A strong electrolyte is a substance that completely dissociates into ions when dissolved in water. This means that all of the molecules of the substance break apart into ions, which are then free to move around in the solution. Strong electrolytes are good conductors of electricity because the ions can carry the charge.

Q150. A total charge of 100C flows through a 12W bulb in a time of 50 second. What is the potential difference across the bulb during this time?

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

Explanation: The potential difference (voltage) across a device can be calculated using Ohm's Law: V=I×R where: V is the potential difference (voltage) across the device, I is the current flowing through the device, R is the resistance of the device. In this case, we have a 12W (watt) bulb. The power P in watts can be related to current I and resistance R by the formula: P=I 2 ×R Given that the power of the bulb is 12W and the current flows for 50 seconds (which implies a total charge of 100C), we can solve for the resistance R: 12W=I2 ×R Since Q=I×t (where Q is the charge, I is the current, and t is time), and we're given that Q=100C and t=50s, we can solve for I: I= Q/t= 100C / 50s=2A Now we can substitute I=2A into the power equation to find R: 12W=(2A)2 ×R R= 12W / 4A2 =3Ω Now that we have the resistance R and the current I, we can calculate the potential difference V using Ohm's Law: V=I×R=2A×3Ω=6V So, the correct answer is: 6.0V

Q151. Becquerel is the unit of:

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

Explanation: The Becquerel (Bq) is the unit of radioactivity or activity. It measures the rate at which a radioactive substance undergoes decay. One Becquerel represents one decay event per second. This unit is named after Henri Becquerel, a physicist who discovered radioactivity.

Q152. The changing electric flux in a certain region of space produces:

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

Explanation: A changing electric flux does indeed produce a magnetic field, as explained by Faraday's law. However, it doesn't directly produce an electric field. The relationship between changing electric flux and induced magnetic field is significant and described by electromagnetic induction. When the magnetic flux through a circuit changes, a nonconservative electric field is induced, which drives current through the circuit. So, changing electric flux produces magnetic ifeld which produces electric field. Hence, option C is correct.

Q153. A hydrogen atom that has lost its electron is moving east in a region where the magnetic moving east in a region where the magnetic fields directed from south to north. It will be deflected:

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

Explanation: A hydrogen atom that has lost its electron is moving east in a region where the magnetic field is directed from south to north will be deflected south. This is because the moving electron will experience a magnetic force that is perpendicular to both its direction of motion and the direction of the magnetic field. The direction of the magnetic force can be determined using Fleming's left-hand rule. According to Fleming's left-hand rule, the thumb points in the direction of the current, the index finger points in the direction of the magnetic field, and the middle finger points in the direction of the force. In this case, the current is in the east direction, the magnetic field is in the north direction, and the force is in the south direction. So, the hydrogen atom will be deflected south.

Q154. The colour of thin films is a result of:

• A. Dispersion
• B. Absorption of light
• C. Scattering of light
• D. None of the above✓

Explanation: The answer is (d). The color of thin films is not a result of any of the options listed. The color of thin films is a result of interference. This means that the light waves reflected from the top and bottom surfaces of the film interfere with each other, and the colors you see are due to the interference patterns that are produced. The colors that you see depend on the thickness of the film, the wavelength of the light, and the angle of incidence of the light. If the thickness of the film is a multiple of half the wavelength of the light, then constructive interference occurs, and you see a bright color. If the thickness of the film is an odd multiple of quarter the wavelength of the light, then destructive interference occurs, and you see a dark color. This is why thin films can appear to be different colors depending on the angle of view. As you rotate the thin film, the thickness of the film changes, and the colors that you see change. However, none of these processes are the primary reason why thin films appear to be different colors. The color of thin films is a result of interference, which is a different process altogether.

Q155. Water flows from a 6.0cm diameter pipe into 8.0cm diameter pipe. The speed in the 6.0cm pipe is 5.0m/s. the speed in the 8cm pipe is:

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

Explanation: GIVEN: Diameter of 1st pipe= 6.0cm r1=d/2= 6/2=3 Diameter of 2nd pipe=8.0 cm r2=d/2=8/2=4 V1=5.0m/s REQUIRED: V2=? SOLUTION: A1V1 = A2V2 (A=𝛑r2) 𝛑 r12 . v1 = 𝛑 r22. v2 32. 5 = 42 . v2 45=16.v2 v2=45/16 v2=2.8m/s

Q156. From the following, which one particle belongs to lepton group:

• A. Neutrinos✓
• B. Protons
• C. Neutrons
• D. Mesons

Explanation: Neutrinos are subatomic particles that belong to the family of elementary particles known as leptons. They are among the most abundant particles in the universe and play a crucial role in various astrophysical and particle physics phenomena. Key characteristics of neutrinos include: 1. Electrically neutral: Neutrinos have no electric charge, which means they do not interact with electromagnetic forces. They are only influenced by weak nuclear forces and gravity. 2. Very low mass: Neutrinos have extremely low mass compared to other elementary particles. While their exact masses are not yet precisely determined, they are much lighter than electrons and other charged particles. 3. Nearly massless and relativistic: Neutrinos are known to travel very close to the speed of light, which makes them nearly massless and relativistic. 4. Three types (flavors): There are three known types or flavors of neutrinos: electron neutrinos (νe), muon neutrinos (νμ), and tau neutrinos (ντ). Each type is associated with a specific charged lepton (electron, muon, and tau, respectively). 5. Oscillation: Neutrinos can undergo a phenomenon called neutrino oscillation, where they can change from one flavor to another as they travel through space. This discovery proved that neutrinos have mass and provided insight into the fundamental properties of these elusive particles. Neutrinos are produced in various astrophysical processes, such as nuclear reactions in the Sun and other stars, supernovae explosions, and cosmic ray interactions. They can travel vast distances through space without much interaction with matter, making them challenging to detect. Neutrino detectors are specially designed to capture and study neutrinos. They use large volumes of materials, such as water or liquid argon, to detect the very rare interactions of neutrinos with other particles. Neutrino research provides valuable insights into the fundamental nature of matter, the early universe, and astrophysical phenomena that involve high-energy processes. Lepton is an elementary particle of half-integer spin (spin 1⁄2) that does not undergo strong interactions .There are six leptons in the present structure, the electron, muon, and tau particles and their associated neutrinos. The rest are Hadrons. Hadron is a subatomic particle of a type including the baryons and mesons, which can take part in the strong interaction.

Q157. An electron in a hydrogen atom makes a transition from an energy level with energy E1, to one with energy E2 and simultaneously emits a photon. The wavelength of the emitted photon is:

• A. hc/(E1 – E2)✓
• B. h/(E1 – E2)
• C. h/c(E1 – E2)
• D. (E1 – E2)/hc

Explanation: But as per ptb, the energy change is given by ∆E=E2-E1 ∆E=hv ∆E=hc/λ E2- E1=hc/λ λ =hc/E2- E1 Ans

Q158. A student measures a current as 0.05 A. Which of the following correctly expresses this result?

• A. 50 mA✓
• B. 50 MA
• C. 500 mA
• D. 500 MA

Explanation: 0.05 A can be written as 50 mA so option A is correct.

Q159. In a nuclear fission reaction, what molecules are produced?

• A. Neutrons✓
• B. Protons
• C. Electrons
• D. Alpha particles

Explanation: When a nucleus fissions, it splits into several smaller fragments. These fragments, or fission products, are about equal to half the original mass. Two or three neutrons are also emitted.

Q160. On the ground, the gravitational force on a satellite is W. What is the gravitational force on the satellite when at a height R/50, where R is the radius of the earth?

• A. 1.04W
• B. 1.02W
• C. 0.50W
• D. 0.96W✓

Explanation: Gravitational force has formula,F=GMm/R2Where G is constant, M is mass of earth ,m is mass of object and R is distance between earth's center and objectOn ground Force= GMm/R2Because distance equals to radius of earthIn given orbit,Force=GMm/(R+R/50)²Taking LCM of R+R/50, we get 51R/50GMm/(51R/50)²GMm/(2601 R²/2500) = GMmx2500/2601R²Equating both these equations:GMm x 2500/2601R²=GMm/R2All the constants will be canceled and we will be left with;2500/2601 = 0.96WSo right option will be D

Q161. If a wave can be polarized, it must be:

• A. An electromagnetic wave
• B. A stationary wave
• C. Transverse wave✓
• D. A longitudinal wave

Explanation: Transverse waves which include all electromagnetic waves such as light, radio waves, and x-rays can be polarized, hence the answer will be C.

Q162. In the nuclear reaction shown below what is the value of coefficient? 92U235+0n1…. 56Kr89+γon1 + 200MeV

• A. 0
• B. 1
• C. 2
• D. 3✓

Explanation: In the fission reaction uranium absorbs a neutron and forms a barium and krypton nucleus which are extremely unstable and they instamtaneously release three neutrons between themselves becoming barium144 and krypton89, therefore the answer is D.

Q163. The vectors A and B are such that |A + B| = |A – B|, then the angle between the two vectors is:

• A. 00
• B. 600
• C. 900✓
• D. 1800

Explanation: Explanation is given in picture

Q164. A zirconium nucleus,is a ß-emitter. The product nucleus is also a ß-emitter. What is the final resulting nucleus of these two decays?

• A. 100Sr38
• B. 100Mo42✓
• C. 98Zr40
• D. 100Zr40

Explanation: In beta decay, mass number reamins the same but proton number increases by 1. Since there are 2 beta decays, proton number will be increased by 2.Zirconium has 40 protons so proton number will increases from 40 t0 42. Thus option B is correct.

Q165. A racing car accelerates uniformly through three gear changes with the following average speeds: 20 ms-1 for 2.0s ;40ms-1 for 2.0 s and 60 ms-1 for 6.0s. What is the overall average speed of the car?

• A. 12 ms1
• B. 13.3 ms-1
• C. 40 ms-1
• D. 48 ms1✓

Explanation: To find the overall average speed we first must find the distance traveled in each gear change, distance=speedxtime (20x2), (40x2), (60x6) Average speed = total distance traveled/time =40+80+360/10 =48 therefore the answer is D

Q166. A generator produces 100 kW of power at a potential difference of 10KV. The power is transmitted through cables of total resistance 5Q. How much power is dissipated in the cables?

• A. 50 W
• B. 750 W
• C. 500 W✓
• D. 1000 W

Explanation: P = 100kWV = 10kVPower dissipated has formula,P = I²RWe have to find current first,We know,P = VII = P / VI = 100kW / 10kVI = 10 ANow finding power,P = I² RP = 10 x10 x 5P = 500 WSo, C option is right

Q167. Read the statement and choose the correct option:

• A. A
• B. B
• C. C
• D. D✓

Explanation: The formula for power is force x velocity so option D is correct.

Q168. Ultraviolet rays differ from the X-rays such that ultraviolet rays _

• A. Cannot be diffracted
• B. Cannot be polarized
• C. Have a low frequency
• D. Do not affect a photographic plate✓

Explanation: Ultraviolet rays do affect photographic plates.

Q169. The first law of thermodynamics is a statement which implies that:

• A. No heat enters or leaves the system
• B. The temperature remains constant
• C. All work is mechanical
• D. Energy is conserved✓

Explanation: The first law of thermodynamics states that energy can neither be created nor destroyed, it is converted from one form to another, therefore the answer will be D

Q170. The function of a main transformer is to convert:

• A. one direct voltage to another direct voltage of different magnitude.
• B. one alternating voltage to another alternating voltage of different magnitude.✓
• C. a high value alternating voltage to low value direct voltage.
• D. A high value alternating current to low value direct voltage

Explanation: A transformer converts a high voltage low current alternating current to a low voltage high current one and vice versa. Therefore the answer will be B.

Q171. If a hole is bored through the center of the earth and a pebble is dropped in it, then it will:

• A. Stop at the center of the earth
• B. Drop to the other side
• C. Execute SHM✓
• D. None of the above.

Explanation: The pebble would fall down to the other side and in a ideal situation would oscillate between the two ends in simple harmonic motion. Therefore the answer would be C.

Q172. The minimum frequency of incident light required to emit photoelectrons from the metal surface is called:

• A. Critical frequency
• B. Threshold frequency✓
• C. Work function
• D. None of the above

Explanation: This minimum frequency is also called the threshold frequency, and the value of ν0​\nu, start subscript, 0, end subscript depends on the metal. For frequencies greater than ν0​\nu, start subscript, 0, end subscript, electrons would be ejected from the metal.

Q173. If two cars are moving with velocity 10 m/s and 5m/s in opposite direction to each other, then their relative velocity with respect to one another will be:

• A. 5m/s
• B. 10m/s
• C. -5m/s
• D. 15m/s✓

Explanation: The relative velocity of the two cars with respect to one another can be found by adding their velocities. Since they are moving in opposite directions, we need to subtract the velocity of one car from the other: Relative velocity = velocity of first car - velocity of second car = 10 m/s - (-5m/s) = 10 m/s + 5 m/s = 15 m/s

Q174. Which among the following phenomenon shows particle nature of light?

• A. Photoelectric effect✓
• B. Interference
• C. Polarization
• D. Matter waves

Explanation: Photoelectric Effect: The phenomenon in which an incident ray of light is ejected from the surface of a metal when light is incident on it, is called the Photoelectric Effect. In photoelectric effect, the light causes electrons to be released on the surface of a metal. When light energy strikes the metal surface, it does so in the form of energy packets. This proves the particle nature of light. Interference: When two waves from different coherent sources interfere with one another such that the phenomenon of superposition ensues and the resultant wave is formed either with a higher, lower, or the same amplitude, we call it interference of light. Interference is a phenomenon caused by the wave nature of light. Polarization: When light waves are transformed from an unpolarized state (where the direction of vibration is in many planes) to a polarized state (where the direction of vibrations for all waves is in the same plane), we call it polarization. Polarization explains the wave nature of light. Matter Waves: The exhibition of wave behavior by elementary particles or atoms results in a matter wave.

Q175. For ideal step up transformer Ps_Pp.

• A. equal to✓
• B. greater than
• C. less than
• D. none of these

Explanation: power remain same.

Q176. The resistance of a conductor at absolute zero ( 0 K) is

• A. Almost zero✓
• B. Almost infinite
• C. No prediction at all
• D. May increase or decrease

Explanation: At absolute zero i.e, 0K which is also the minimum temperature, the Resistance of the conductor becomes minimum but not exactly zero.

Q177. During adiabatic expansion internal energy decreases by 2J, then work done in this process is

• A. 2J✓
• B. 1J
• C. -1J
• D. -2J

Explanation: In an adiabatic process, the net of a system remains 0. The equation for heat is given by;Q = ΔU + WAs the heat energy is 0;0 = ΔU + WTherefore, W = -ΔUThere is a 2J decrease in the internal heat U, which can be written as -2J, with the negative signrepresenting the decrease. Thus, by the equation, work done is +2J.

Q178. If system changes from a state Pl Vl to P2V2 by two paths then quantity which remains unchanged is

• A. dQ
• B. dW
• C. dQ-dW✓
• D. dQ+dW

Explanation: In a thermodynamic process, the internal energy (ΔU = ΔQ - ΔW) is a state function, therefore it depends only on the initial and the final points of the system, thus remaining unchanged.

Q179. The radiations all around us are called _ radiations

• A. natural
• B. artificial
• C. both a or b✓
• D. no radiation is around us

Explanation: Humans come into contact with radiation on a daily basis. These radiations are both natural, such as the rays from the sun, and artificial, such as those from our TV screens or kitchen stoves. This radiation that we experience on a daily basis is known as background radiation

Q180. A.C and D.C have the same:

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

Explanation: The correct option is "Effect in charging battery." Charging a battery with both AC and DC currents can have a similar effect in terms of replenishing the battery's energy storage. However, the charging process and efficiency might vary between AC and DC due to factors such as the battery chemistry, charging circuitry, and voltage regulation. It's important to note that while the overall effect of charging a battery can be similar, the underlying mechanisms and technical considerations might differ between AC and DC charging methods.

Q181. X-rays are widely used as a diagnostic tool in medicine because of its:

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

Explanation: X-rays are a type of electromagnetic radiation that can pass through most objects, including the human body. When x-rays hit human tissue, they produce an image that can be used to detect medical conditions. An X-ray procedure and x-ray equipment are used to diagnose and treat medical conditions, as they can: Diagnose broken bones – one of the most common uses for this type of medical imaging. Detect other medical conditions, such as tumors, internal bleeding, or cancer detection (such as breast cancer). X -rays have high penetrating power. X -rays have high frequencies of the range 10 power 16 Hz to 10 power 20 Hz. According to Planck's equation for energy of a photon, E=hυ E= Energy of photon h=planck's constant=6.63×10-34 Js υ=Frequency of photon in Hertz Hence, energy of a photon, E is directly proportional to the frequency of a photon,υ E∝υ Now,since X-rays have high frequency, consequently they have high energy. And therefore high penetrating power. ∴ X-rays have high penetrating power because of their high frequency.

Q182. A charged capacitor stores 10 C at 40 V. Its stored energy is:

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

Explanation: .

Q183. A vector of magnitude 20 is added to a vector of magnitude 25. The magnitude of this sum might be:

• A. Zero
• B. 3
• C. 12
• D. 47✓

Explanation: The magnitude of the sum of two vectors can be determined using the triangle law of vector addition. This law states that if two vectors are represented as sides of a triangle, then the sum of the two vectors can be represented by the third side of the triangle. In this case, if a vector of magnitude 20 is added to a vector of magnitude 25, the magnitude of the sum could be anywhere between ∣20−25∣=5 (if the two vectors are in opposite directions) and 20+25=45 (if the two vectors are in the same direction). Out of the given options, the closest one to the potential range of magnitudes is: 47 However, it's important to note that the exact magnitude of the sum will depend on the relative directions of the two vectors. The magnitude will be smaller if they are opposing and larger if they are aligned.

Q184. The time period of a simple pendulum is 2 seconds. If its length is increased by 4 times, then its period becomes:

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

Explanation: T=2π √ l/g T∝ √ l As we know that T1 is 2s so, l=1m If the length is increased by 4 times T1/T2 = √ l1/l2 2s/T2= √ 1m/4m 2s/T2=1/2 BY CROSS MULTIPLICATION T2=4 sec

Q185. A moving charged particle is surroundes ??

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

Explanation: A moving charged particle is surrounded by 2 fields, one is an electric field due to charge and the other is a magnetic field due to the motion of the charges.

Q186. The infrared spectra commonly referred to as IR spectra is usually expressed as:

• A. Wave length
• B. Wave number
• C. Frequency
• D. All of the above✓

Explanation: The answer is (d). Infrared spectra, commonly referred to as IR spectra, are usually expressed as wavelength, wavenumber, or frequency. Wavelength: This is the distance between two consecutive peaks in the spectrum. Wavelengths of infrared radiation range from about 700 nanometers (nm) to 1 millimeter (mm). Wavenumber: This is the reciprocal of the wavelength, and it is expressed in units of reciprocal centimeters (cm-1). Wavenumbers are often used in IR spectroscopy because they are independent of the physical properties of the sample, such as its temperature and pressure. Frequency: This is the number of waves that pass a given point in space per unit time. Frequencies of infrared radiation range from about 1013 to 1014 hertz (Hz). The choice of which unit to use depends on the specific application. Wavelength is often used when comparing spectra from different sources, such as different materials or different conditions. Wavenumber is often used when calculating the energies of molecular vibrations, which are related to the wavenumber of the IR absorption. Frequency is often used when calculating the speed of IR radiation, which is related to the frequency of the radiation. In general, IR spectra can be expressed in any of the three units, but wavelength, wavenumber, and frequency are the most common.

Q187. When released from a height a ball falls 5m in 1s. In 4s after release the ball will fall:

• A. 40m
• B. 80m✓
• C. 20m
• D. 100m

Explanation: Since, s = ut + ½ at² u = 0, a = g t = 4s g ≈ 10 ms-²Then, s = (0)(4) + ½ (10)(4)² s = 0 + ½ (10)(16) s = ½ (160) s = 80m

Q188. If the momentum of a body decreases by 20% the percentage decrease in K.E will be:

• A. 44%
• B. 36%✓
• C. 28%
• D. 20%

Explanation: Momentum p = mvIf momentum is decreased by 20%, the resulting new value is 80% of the original p-p' P - 0.2p = mv - m0.2v P - 0.2p = (m) (v) (0.8) K.E = ½ mv² = ½ m (0.64v²) K.E = 36%

Q189. An organ pipe is open at both ends at its fundamental frequency. Neglecting any end effects, what wavelength is formed by this pipe in this mode of vibration, if the pipe is two meter long?

• A. 2m
• B. 4m✓
• C. 6m
• D. 8m

Explanation: For an open pipe at both ends, the fundamental frequency is given by: f = v/2LWhere v is the speed of sound and L is the length of the pipe.We can rearrange this equation to solve for the wavelength (λ): λ = 2LSubstituting the given value of L = 2m, we get: λ = 2 (2) = 4mTherefore, the wavelength formed by this pipe in its fundamental frequency is 4m.

Q190. Balmer series lies in that region of electromagnetic wave spectrum, which is known as:

• A. Visible region✓
• B. Ultraviolet region
• C. Invisible region
• D. lnfra-red region

Explanation: The Balmer series corresponds to the set of spectral lines in the emission spectrum of hydrogen atoms that result from electron transitions within the atom involving the principal quantum number "n" ranging from 3 to higher levels down to n = 2. These transitions result in the emission of photons with specific energies. The Balmer series is located in the visible region of the electromagnetic spectrum, which ranges from approximately 400 to 700 nanometers (nm). It includes colors that are visible to the human eye.

Q191. Which one of the following pair is of isobars?

• A. 126 C and 146 C
• B. 614 C and 714N✓
• C. 42 He and 31H
• D. Both A and C

Explanation: Isobars have different atomic number but same atomic mass. This option clearly shows elements having same atomic mass but different atomic number.

Q192. A radioactive isotope 'W' decays to 'X' which decays to 'Y' and 'Y' decays to 'Z' as represented by the figure below What is the change in the atomic number from 'W' to 'Z'?

• A. Increase by 3
• B. Increase by 5
• C. Decrease by 3✓
• D. Decrease by 5

Explanation: The explanation for this question will be added soon!

Q193. Wave nature and particle nature of photon is linked by:

• A. Rest mass of photon
• B. Wavelength of photon
• C. Light speed
• D. Momentum of photon✓

Explanation: Particle nature and wave nature of electromagnetic waves and electrons is called dual nature or wave particle dualism. According to this wave particle dualism, a wave can also exhibit particle behavior and at the same time, a particle can also exhibit wave nature. Momentum of a photon is considered in both the particle and wave nature of a photon.

Q194. In the following question, various terms of an alphabet sequence are given with one or more terms missing as shown by (?). Choose the missing term.Z, ?, T, ?, N, ?, H, ?, B

• A. W, Q, K, E✓
• B. W, R, K, E
• C. X, Q, K, E
• D. X, R, K, E

Explanation: The explanation of this question will be added soon.

Q195. Directions: Read the following information and give answer. Ghulam Rasool is shorter than Ali but taller than Kamran. Naeem is shorter than Kamran. Jameel is taller than Naeem. Ali is taller than Jameel. Who among them is the tallest?

• A. Ali✓
• B. Naeem
• C. Kamran
• D. Jameel

Explanation: By arranging the statements in decreasing order we get; Ali > Ghulam Rasool > Kamran> Naeem Ali >Jameel > Naeem So, Ali is tallest of them all.

Q196. Statement: The increasing population of our nation will lead to the depletion of many essential resources. Conclusion: I. Population of our nation can be controlled. II. The nation will not be able to provide a decent living to its citizens.

• A. Only conclusion I follows.
• B. Only conclusion II follows.✓
• C. Either conclusion I or II follows.
• D. Both conclusion I and II follows.
• E. None of these.

Explanation: Only conclusion II follows as the nation will not be able to provide a decent living to its citizens because of the increasing population of our nation.

Q197. STATEMENTS: I. The dialogue between Jinnah and Gandhi failed. Il. Indian National Congress and Muslim League tried to join hands, so they will be united.

• A. Statement I is the cause and statement II is its effect.
• B. Statement II is the cause and statement I is its effect.
• C. Both statements I and II are independent causes
• D. Both statements I and II are the effects of independent cause.✓

Explanation: Gandhi and Jinnah were unable to reach a decision regarding Pakistan hence the dialogue failed. In order to show a united front to the British as they believe that would help them achieve independence INC and ML tried to join hands(work together). Thus both these statements are effects of independent causes

Q198. Statements: All flowers are trees. No fruit is tree. Conclusions: I. No fruit is flower. II. Some trees are flowers. Which of the following is/are most appropriate in the above scenario?

• A. Only I
• B. Only II
• C. I and II✓
• D. I and II are inappropriate

Explanation: The explanation for this question will be given later.

Q199. Statement: There is an unprecedented increase in the migration of villagers to urban areas as repeated crop failure has put them into a precarious financial situation.Courses of Action:I. The villagers should be provided with an alternate source of income in their villages which will make them stay put.II. The migrated villagers should be provided with jobs in the urban areas to help them survive.

• A. Both of the courses of action follow
• B. None of the courses of action follow
• C. Only course of action I follows✓
• D. Only course of action II follows

Explanation: Increased migration would add to the burden on the city's infrastructure. So, attempts should be made to make the villagers feel comfortable in the villages themselves, the only course of action I follows.