Kpk Mdcat Mock Paper 1 — Solved Past Paper with Answers

Q1. Choose the correct option:

• A. A
• B. B
• C. C✓
• D. D

Explanation: This option is correct as everything is placed under right category as described above.

Q2. Choose the word most similar in meaning to the given word: REAL

• A. Copied
• B. Idea
• C. Original✓
• D. Given

Explanation: C is correct option because Word Real is an adjective in nature having similar meaning as genuine authentic actual. So the correct synonym for real is original.

Q3. Complete the sentences by choosing the most appropriate option, from the given lettered choices (A to D) below each: The house _ before we moved in.

• A. Paint
• B. Painted
• C. Has painted
• D. Was painted✓

Explanation: The key to solving these questions is reading them in your head filling in each option and then deciphering which option fits in well. The sentence here is clearly in the past tense hence Option D is the correct option as it indicates the house was painted.

Q4. In each of the following questions, four alternative sentences are given.Choose the CORRECT option.

• A. Norma had put the button unit besides her on the couch.
• B. Norma put an button unit besides her on the couch.
• C. Norma put the button unit besides hers on the couch.
• D. Norma put the button unit beside her on the couch.✓

Explanation: The phrase "beside her" is used in the sentence to indicate the location of the button unit in relation to Norma. "Beside" means next to or by the side of someone or something. In this case, it suggests that Norma placed the button unit in close proximity to herself, likely on the couch within reach. The phrase provides spatial information and helps to specify the position of the button unit in relation to Norma.

Q5. Each sentence below has a blank indicating that something has been omitted. Choose the word that best fits in with the meaning of the sentence as a whole.Though the apprentice was a highly proficient IT professional, he had little or no _ in designing educational software.

• A. Creativity✓
• B. Prospect
• C. Configuration
• D. Competition

Explanation: The first word, “Though,” is an opposition indicator. The beginning of the sentence speaks positively about the IT professional. We must find a word that gives us a negative idea about him. Choice A, creativity, is the appropriate word though it is positive word but no or little makes it negative. The other choices are incorrect because their words are not appropriate to give us that opposite feeling.

Q6. Each sentence below has a blank indicating that something has been omitted. Choose the word that best fits in with the meaning of the sentence as a whole.The foreman’s clemency, particularly in being candid, had its _, one of which was _workmanship.

• A. Damages ... intolerable
• B. Ambiguities ...superior
• C. Shortcomings ...shoddy✓
• D. Occurrences ...attractive

Explanation: The words that best fit the sentence are Shortcomings ... shoddy.Shortcomings fits because it describes deficiencies or weaknesses resulting from the foreman's clemency.Shoddy fits because it describes poor quality workmanship, which is one of the consequences mentioned.In this sentence, the foreman's leniency (clemency) in being candid (honest or straightforward) had negative consequences. One of these consequences was shortcomings, meaning deficiencies or weaknesses. One such weakness was shoddy workmanship, meaning poor quality. This fits the context provided where the foreman's positive trait (clemency) resulted in negative outcomes (poor workmanship).

Q7. Select the most suitable synonym for the given word: CAPACIOUS

• A. Ample✓
• B. Cramped
• C. Stagnant
• D. Dormant

Explanation: Capacious is synonymous to roomy, having a generous amount of space.

Q8. In the following question, four alternative sentences are given. Choose the CORRECT one.

• A. In my experience, the awakening of that clear judgemeent as to what the college is for, is not as difficult as is often supposed.
• B. In my experience, the awakening of a clear judgement as for what the college is for,is not as difficult as is often supposed.
• C. In my experience, the awakening of a clear judgement as to what the college is for, is not as difficult as is often supposed.✓
• D. In my experience, the awakening of a clear judgement as to what the college is for, is not as much as difficult as often supposed.

Explanation: The best way to solve this question is to read each option in your head and then decide which one sounds the best and fits in well. In Option A, the spelling of judgement is incorrect. In Option B, there is no space left after the comma which is the wrong punctuation. In Option D, as much as is unnecessary text and can be removed.

Q9. I'm now going to give you 10 _ tips for running a really successful website.

• A. Invaluable✓
• B. Valueless
• C. Unworthy
• D. Unprofitable

Explanation: Option A: Invaluable is defined as something extremely useful; indispensable. Since these tips will help create a successful website, they are extremely helpful and thus important, making them invaluable. Option B : Valueless: This answer is incorrect as the tips provided for running a successful website are likely to be valuable and useful for website owners. Option C : Unworthy: This answer is incorrect as the tips provided for running a successful website are likely to be worthy of consideration for website owners looking to improve their website's performance. Option D : Unprofitable: This answer is incorrect as the tips provided for running a successful website may not necessarily be focused on generating profits, but rather on improving the website's overall performance and user experience.

Q10. His bag was quite _ so I easily carried it to his room.

• A. Cheap
• B. Heavy
• C. Light✓
• D. Short

Explanation: Since the bag was light, it was easy to carry.

Q11. Demonstrate the control of tenses and sentence structure in the following sentence: I _ (eat) an apple.

• A. Eat
• B. Eaten
• C. Eating
• D. Ate✓

Explanation: ‘Eaten’ [Option B] and eating[option C] requires helping verbs before them [e.g am/have]. As these helping verbs are not given in the sentence so these options are eliminated. Option D: ‘ate’ is the past tense of ‘eat’ which is most appropriate choice.

Q12. Comprehend key vocabulary This medicine is _ from plants.

• A. Deprived
• B. Derived✓
• C. Derisive
• D. Derivative

Explanation: i.e derive which means to obtain or deduce something

Q13. Choose the correct sentence from the following options:

• A. Shahid battered Anwar down submission.
• B. Shahid battered Anwar into submission✓
• C. Shahid down battered Anwar into submission.
• D. Shahid was battered Anwar down submission.

Explanation: Option B is correct because it has the most correct sentence structure. It should be into submission not down submission, according to the correct use of grammar. There are only two options having this proper use(B and C). Option C has a major grammatical flaw: “Shahid down battered Anwar” hence it can not be our answer.

Q14. Anum asked me, "Did you see the drama on television last night?" [Choose the correct indirect speech]

• A. Anum asked me whether I saw the drama on television the earlier night.
• B. Anum asked me whether I had seen the drama on television the earlier night.
• C. Anum asked me did I see the drama on television the last night.
• D. Anum asked me whether I had seen the drama on television the last night.✓

Explanation: Interrogative sentences beginning with an auxiliary verb are changed into indirect speech using the connective if or whether. The reporting verb said (or any other word used as the reporting verb) changes to asked, queried, questioned, demanded of, or enquired of in the indirect speech. Note that of is used after enquired and demanded only when the reporting verb has an object. So D will be the correct option

Q15. Choose the word opposite in meaning to "VOCIFEROUS"

• A. Silent✓
• B. Boisterous
• C. Blatant
• D. Noisy

Explanation: ociferous means expressing or characterized by vehement opinions; loud and forceful. Boisterous means noisy, cheerful and energetic. Blatant means have done openly and unashamedly. So the correct option is A as it is the opposite of Vociferous.

Q16. Which way shall we go? [The underlined word is:]

• A. Demonstrative adjective
• B. Interrogative pronoun
• C. Interrogative adjective✓
• D. Exclamatory adjective

Explanation: Interrogative adjectives are such adjectives that modify the noun, are always followed by a noun, and can’t stand alone. It included which, what, and who. Since in the above question “which” is followed by a noun, the correct answer is C.

Q17. My mother offered me milk. But for my life, I could not drink it. [The underlined expression means:]

• A. However hard I may try✓
• B. Because of my life
• C. For the sake of my life
• D. During my life

Explanation: My mother offered me milk. But for my life, I could not drink it. [The underlined expression means:] However hard I may try

Q18. Choose the related word for Broom on the analogy of; Water : Splash.

• A. Whisper
• B. Gush
• C. Swish✓
• D. Screech

Explanation: Water makes a splashing sound whereas a broom makes a swish sound as of a whip cutting the air, hence C is the right answer.

Q19. In which model do proteins float in membrane-like iceberg in sea:

• A. Lock and key model.
• B. Induced fit model.
• C. Fluid mosaic model.✓
• D. Lotka volterra model.
• E. All of these.

Explanation: As per the fluid mosaic model cell membranes have proteins as icebergs in a sea of lipids (lipid). Hence option C is correct.

Q20. Which of the following are not polymeric?

• A. Proteins
• B. Polysaccharides
• C. Lipids✓
• D. Nucleic acids

Explanation: In summary, "c) Lipids" are not polymeric, while "a) Proteins," "b) Polysaccharides," and "d) Nucleic acids" are polymeric substances composed of repeating monomeric units.

Q21. What are the components of a nucleotide?

• A. purine, pyrimidine and phosphate
• B. purine, sugar and phosphate
• C. nitrogen base, sugar and phosphate✓
• D. pyrimidine, sugar and phosphate

Explanation: (c) : A nucleotide is an organic compound consisting of a nitrogen­ containing purine or pyrimidine base linked to a sugar (ribose or deoxyribose) and a phosphate group.

Q22. A segment of DNA has 120 adenine and 120 cytosine bases. The total number of nucleotides present in the segment is

• A. 120
• B. 240
• C. 60
• D. 480.✓

Explanation: (d) : According to Chargaff’s rules, the amount of adenine is always equal to that of thymine, and the amount of guanine is always equal to that of cytosine i.e.,A = T (120) and G = C (120), therefore, the total no. of nucleotides would be 120 × 4 = 480.

Q23. _ fats are solid at room temperature.

• A. Animal✓
• B. Plant
• C. All
• D. None

Explanation: Animal fatty acids are saturated fatty acids and have higher melting points. Hence they are solid at room temperature.

Q24. A → B → C → D → E Accumulation of “E” will control the above pathway through:

• A. Feedback mechanism
• B. Feedback activation
• C. Positive feedback
• D. Feedback inhibition✓

Explanation: Cell have limited space thus product should be produced according to need. The excess cause storage disorders. Thus upon accumulation of end products, the pathway is inhibited from first step and this is called feedback inhibition and vice versa.

Q25. Which of these enzymes works best at a pH of 9.70?

• A. Arginase✓
• B. Pancreatic lipase
• C. Catalase
• D. Chymotrypsin

Explanation: Arginase Works at a pH of 9.70.

Q26. Which of the following cell organelles is responsible for extracting energy from carbohydrates to form ATP?

• A. Ribosome
• B. Chloroplast
• C. Mitochondrion✓
• D. Lysosome

Explanation: Mitochondria are miniature biochemical factories where food stuffs or respiratory substrates are completely oxidised to carbon dioxide and water. The energy liberated in the process is initially stored in the form of reduced coenzymes and reduced prosthetic groups.The latter soon undergo oxidation and form energy rich ATP. ATP comes out of mitochondria and helps perform various energy requiring processes of the cell like muscle contraction, nerve impulse conduction, biosynthesis, membrane transport, cell division, movement, etc. Because of the formation of ATP, the mitochondria are called power houses of the cell.

Q27. Microtubules are the constituents of

• A. centrioles, spindle fibres and chromatin
• B. centrosome, nucleosome and centrioles
• C. cilia, flagella and peroxisomes
• D. spindle fibres, centrioles and cilia.✓

Explanation: The correct answer is d) Spindle fibers, centrioles, and cilia. Microtubules are constituents of these structures, playing vital roles in cell division, chromosome movement, and cellular movement.

Q28. Which one of the following are the correct pairing of a body part and the kind of muscle tissue that moves it?

• A. Biceps of the upper arm – Smooth muscle fibres
• B. Abdominal wall – Smooth muscle
• C. Iris – Involuntary smooth muscle✓
• D. Heart wall – Involuntary unstriated muscle

Explanation: Smooth muscles are called involuntary muscles because the action of these muscles is controlled by the autonomic nervous system i.e. it is not under the control of the animal’s will. The iris of the eyes consists of smooth involuntary muscles. The abdominal wall also has smooth muscles. The biceps of the upper arm are made of skeletal muscles while the heart wall consists of cardiac muscle

Q29. sarcolcmma is primarily made up of:

• A. Lipoprotein✓
• B. Glycolipids
• C. Glycoprotein
• D. Nucleoproteins

Explanation: Since sarcolemma is the membrane of muscle cells, so its chemical compostion is hpoproteins.

Q30. Sertoli cells are found in:

• A. Ovaries and secrete progesterone
• B. Adrenal cortex and secrete adrenaline
• C. Seminiferous tubules and provide nutrition to germ cells✓
• D. Pancreas and secrete cholecystokinin

Explanation: Sertoli cells are specialized cells found in the seminiferous tubules of the testes. They play a crucial role in supporting and nourishing the developing germ cells (sperm cells) during spermatogenesis, which is the process of sperm production. Sertoli cells provide physical support, produce essential proteins and growth factors, regulate hormone levels, and create a suitable microenvironment for the maturation of sperm cells.

Q31. When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe?

• A. Falling CO2 concentration
• B. Rising CO2 and falling O2 concentration
• C. Falling O2 concentration
• D. Rising CO2 concentration✓

Explanation: (d): Excess CO2 mainly stimulates the respiratory center of the brain and increases the inspiratory and expiratory signals to the respiratory muscles. O 2 does not have a significant direct effect on the respiratory center of the brain in controlling respiration.

Q32. Which of the following is derived from Latin word VENUME which means poisonous?

• A. Bacteria
• B. Fungi
• C. Virus✓
• D. Malaria

Explanation: The word virus is derived from LATIN word VENUME which means poisonous.

Q33. Avidin is a protein that

• A. binds egg white with biotin✓
• B. binds egg white with egg albumin
• C. both a and b
• D. this protein do not belong to egg white

Explanation: Avidin is a glycoprotein that combines specifically with biotin, a vitamin.

Q34. Cells which kills cells that display foreign motifs on their surface are

• A. Platelets
• B. Cytotoxic T cells✓
• C. Antigens
• D. Red blood cell

Explanation: T cells are direct fighters of foreign invaders. Also called cytotoxic T cell and cytotoxic T lymphocyte.

Q35. Amphibians are poikilotherms, therefore they use to hibernate in

• A. Winter✓
• B. Summer
• C. Autumn
• D. Spring

Explanation: Poikilotherm is an organism with a variable body temperature that is usually slightly higher than the temperature of its environment : a cold-blooded organism—called also heterotherm.Poikilothermic animals include types of vertebrate animals, specifically some fish, amphibians, and reptiles, as well as many invertebrate animals.Poikilothermic,or cold blooded animals face a risk of death due to cold or freezing over the winter so they go into hibernation during winter season.

Q36. Purkinje fibres are connected with the impulse conducting system of

• A. Heart✓
• B. Brain
• C. Skin
• D. Nephron

Explanation: The Purkinje fibers are located in the inner ventricular walls of the heart, just beneath the endocardium in a space called the subendocardium. The Purkinje fibers are specialized conducting fibers composed of electrically excitable cells. It is the extension of the autonomic nervous system and first discovered by Jan Avenglesta Purkine in 1839.

Q37. Some marine fishes possess salt excreting organs known as

• A. Thyroid gland
• B. Pituitary gland
• C. Adrenal gland
• D. Rectal gland✓

Explanation: The rectal gland, The salt gland is an organ for excreting excess salts. It is found in the cartilaginous fishes subclass elasmobranchii (sharks, rays, and skates), seabirds, and some reptiles.

Q38. Diphtheria vaccines is an example of:

• A. Inactivated vaccine
• B. Toxoid vaccine✓
• C. Subunit vaccine
• D. Live, attenuated vaccine

Explanation: Toxoid vaccines contain a toxin or chemical made by the bacteria or virus. They make you immune to the harmful effects of the infection, instead of to the infection itself. Examples are the diphtheria and tetanus vaccines.

Q39. A bacterium which has a group of two or more flagella inserted at one pole of the cell

• A. Monotrichous
• B. Peritrichous
• C. Lophotrichous✓
• D. Amphitrichous

Explanation: There are four types of flagellar arrangements based on the number and placement of flagella on the cell. These are, 1. Monotrichous - A single flagellum extends from one end of the cell. 2. Amphitrichous - A single flagellum or multiple flagella extend from two ends of the cell. 3.Lophotrichous - Tufts of flagella extend from one end or both ends of the cell. 4. Peritrichous - Multiple flagella randomly distributed over the entire bacterial cell. Thus, the correct answer is 'Lophotrichous.'

Q40. Opossum and koala bear belongs to sub-class

• A. Prototheria
• B. Eutheria
• C. Metatheria✓
• D. Monotremata

Explanation: Opossums and koala bears belong to subclass metatheria.

Q41. DNA polymerase III works always in

• A. 5 - 2' direction
• B. 5'- 3' direction✓
• C. 3'- 5 direction
• D. 2 - 5 direction

Explanation: DNA polymerase can only make DNA in the 5’ to 3’ direction.

Q42. Which factor is not involved in release of Oxytocin in females:

• A. Stretching of uterus
• B. Stretching of Cervix
• C. Low level of testosterone✓
• D. Low level of progesterone

Explanation: As testosterone is the sex hormone of males, low secretion of luteinizing hormone (LH) and follicle-stimulating hormone cause low levels of testosterone.

Q43. A heterozygote fruit fly has more florescent pigments in their eyes than a wild homozygote fruit fly, this is an example of:

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

Explanation: When the phenotypic expression of heterozygotes becomes more intense than the homozygous state of the dominant allele, is called over-dominance. So, the above example is an example of Over dominance.

Q44. Vomit centre is located in:

• A. Pons
• B. Mid brain
• C. Cerebellum
• D. Medulla✓

Explanation: The Medulla oblongata is the posterior portion of the brain. Special reflexes such as heart beat, respiratory movement, salivary secretion, swallowing, vomiting, coughing, and sneezing are located in the medulla oblongata.

Q45. Which of the following is the suitable vector to be incorporated with the large external DNA fragment?

• A. Small size vector✓
• B. Large size vector
• C. Large size vector with no origin of replication.
• D. Small size vector with no origin of replication.

Explanation: In molecular cloning, a vector is a DNA molecule used as a vehicle to artificially carry foreign genetic material into another cell, where it can be replicated and/or expressed. A vector containing foreign DNA is termed recombinant DNA. A small size is the suitable vector to be incorporated with the large external DNA fragment because it should be small in size so that it can easily integrate into the host cell. It should be capable of inserting a large segment of DNA. It should possess multiple cloning sites.

Q46. If black and white true breeding mice are mated and they result is all gray offspring, what inheritance pattern would this be indictive of ?

• A. Dominance
• B. Co dominance
• C. Multiple alleies
• D. Incomplete dominance✓

Explanation: Codominance means that no allele can block or mask the expression of the other allele. While incomplete dominance is a condition in which a dominant allele does not completely mask the effects of a recessive allele so the correct option is D as black and white parents produce gray offsprings

Q47. Calcium ions bind with the troponin molecule and cause them to:

• A. Extend
• B. Move slightly✓
• C. Contract
• D. Remain in the same position

Explanation: When the muscle is required to contract, calcium ions bind with troponin molecule and cause them to move slightly.This has the effect of displacing the tropomycin and exposing the binding sites for the myosin head.

Q48. All of the following protect the body against entrance of germs except:

• A. Tears
• B. Mucus membrane
• C. WBCs
• D. Ciliated cells
• E. RBCs✓

Explanation: Option E is correct.RBCs have no role in immunity. RBCs (red blood cells) do not protect the body against the entrance of germs. RBCs are responsible for carrying oxygen to the tissues and carbon dioxide away from the tissues. They do not have the ability to engulf or kill germs.

Q49. During muscles relaxation the calcium ions are

• A. Released from sarcoplasmic reticulum into Sarcoplasm
• B. Forced back from the sarcoplasm to sarcoplasmic reticulum✓
• C. Further Forced from sarcoplasmic reticulum into sarcoplasm
• D. Neither released more nor forced back but remain constant

Explanation: When muscles relax, the calcium ions are forced / pumped back from the sarcoplasm into the sarcoplasmic reticulum so that the globular head can remove itself from the acting binding site

Q50. Venous flower basket belong to which group of organisms:

• A. Angiosperms
• B. Sponges✓
• C. Marine Algae
• D. Fungus like protists

Explanation: Venous flower basket belong to sponges ( phylum porifera).

Q51. Which of the following is not the part of first line of defense?

• A. Sebum
• B. Perspiration
• C. Interferon✓
• D. Epidermis

Explanation: The first line of defense is formed by external barriers, such as skin and mucous membranes. The second line of defense is provided by phagocytes, natural killer cells, antimicrobial proteins, and inflammatory response. Important antimicrobial proteins include lysozyme, complement proteins, and interferons. Interferons are small proteins, secreted by virally infected cell lymphocytes. They create anti-viral resistance in healthy uninfected body cells. The adaptive immune system forms the third line of defense of the body. It depends on two types of lymphocytes called B-cells and T-cells.

Q52. In which of the following the female workers are sterile ?

• A. Ants
• B. Honeybee✓
• C. Baboon
• D. Parrots

Explanation: The worker bee and the queen bee are both female but only the queen bee can reproduce. All drones are male. Worker beans clean the hive, collecting Pollen and nectar to feed the colony and they take care of the offsprings. The drones only job is to mate with the queen with the queen

Q53. The usual position of the two centrioles in relation to each other is at right angle in:

• A. Higher plant cells
• B. Lower plant cells
• C. Animals cells
• D. Both (B) &(C)✓

Explanation: Only lower plant cells and animal cells have centrioles at right angle to each other so correct option is D

Q54. Of 100 ml of arterial blood, oxygen provided to the tissues is:

• A. 2ml
• B. 3ml
• C. 4ml
• D. 5ml✓

Explanation: 6 mL of oxygen is delivered, at tissue level in normal conditions so option D is correct

Q55. Enzymes work by lowering the _ of the reactions they catalyse:

• A. Kinetic energy
• B. Activation energy✓
• C. Heat energy
• D. Potential energy

Explanation: Activation Energy is the minimum amount of energy that the reacting species must possess in order to undergo a specified reaction. Enzymes speed up reactions by lowering this energy and hence the reaction occurs faster by the virtue of more reactants being capable of initiating and taking part in the reaction due to the lowered energy threshold. Kinetic energy (KE) of an object is the energy that it possesses due to its motion. Heat energy is the result of the movement of tiny particles called atoms, molecules or ions in solids, liquids and gases. Potential energy is energy that is stored – or conserved - in an object or substance. This stored energy is based on the position, arrangement or state of the object or substance. You can think of it as energy that has the 'potential' to do work.

Q56. First stable compound during Calvin cycle is:

• A. 3-phosphoglycerate✓
• B. Glyceraldehyde 3 - phosphate
• C. 1, 3 bisphosphoglycerate
• D. Ribulose bisphosphate

Explanation: The first stable compound in the Calvin cycle is a 3 carbon compound namely 3 phosphoglyceric acid (PGA). Hence the Calvin cycle is also called as C3 cycle. This compound is produced by carbon dioxide fixation reaction catalyzed by ribulose 1, 5 bisphosphate carboxylase/ oxygenase (RUBISCO) enzyme, which carboxylates one molecule of five carbon atom-containing compound, ribulose 1, 5 bisphosphate (RUBP) into two molecules of the three carbon atom-containing compound 3 PGA.

Q57. Which of the following is a copper containing protein in electron transport chain?

• A. Plastoquinone
• B. Cytochrome - C
• C. Plastocyanin✓
• D. Ferredoxin

Explanation: It serves as an electron transfer agent between the cytochrome complex which follows Photosystem II and the entry point to Photosystem I of the non-cyclic electron transfer process. The electron transport chain is a series of electron transporters embedded in the inner mitochondrial membrane that shuttles electrons from NADH and FADH2 to molecular oxygen. In the process, protons are pumped from the mitochondrial matrix to the intermembrane space, and oxygen is reduced to form water.

Q58. This theory says that “mitochondria and chloroplasts are, in effect, ancient bacteria which now live inside the larger cells”:

• A. Darwin’s theory of evolution
• B. Lamarckism
• C. Neo - darwinism
• D. Endosymbiont theory✓

Explanation: The endosymbiotic theory states that some of the organelles in today's eukaryotic cells were once prokaryotic microbes. They eventually lost their cell wall and much of their DNA because they were not of benefit within the host cell. Mitochondria and chloroplasts cannot grow outside their host cell. The illustration of the prokaryotic microbes penetrating into the now called eukaryotes is presented below:

Q59. The complete, mature and infection virus particle is known as:

• A. Venome
• B. Genome
• C. Virion✓
• D. Capsid

Explanation: Viruses are a small obligate intracellular parasite, containing either RNA or DNA surrounded by a virus protein coat. A complete virus particle is called a Virion. The main function of the virion is to deliver its DNA or RNA genome into the host cell so that the genome can be expressed in the host cell. So, the correct answer is 'Virion'.

Q60. Photophosphorylation takes place in the _ of the chloroplasts:

• A. Stroma
• B. Granum✓
• C. Inner membrane
• D. Outer membrane

Explanation: Photophosphorylation takes place in the thylakoid membrane of the chloroplasts. The thylakoid membrane is a membrane system within the chloroplast that contains chlorophyll and other pigments involved in capturing light energy during the light-dependent reactions of photosynthesis. The chloroplast is an organelle with various compartments, including the stroma, thylakoid membrane, and granum. The thylakoid membrane, where photophosphorylation occurs, is located within the chloroplast and is organized into stacks called grana (singular: granum). The grana contain the thylakoid discs where the light-dependent reactions of photosynthesis, including photophosphorylation, take place.

Q61. Regarding structure of the human heart, Chordae Tendinae are present in:

• A. Atria
• B. Pulmonary valve
• C. Ventricles✓
• D. Aortic valve

Explanation: The chordae tendinae (tendinous cords), colloquially known as the heartstrings, are tendon-resembling fibrous cords of connective tissue that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart. Hence are placed in the ventricles, as shown in the diagram below:

Q62. Vertebrates belong to phylum chordata because:

• A. They have a vertebral column
• B. The brain is enclosed by the skull
• C. The embryos have gills
• D. The body develops from three germinal layers✓

Explanation: Chordates, including vertebrates, undergo embryonic development with three primary germinal layers: ectoderm, mesoderm, and endoderm. These layers give rise to different tissues and organs, enabling the complex body development seen in chordates.

Q63. Each air-sac consists of several microscopic single layered structures called:

• A. Bronchioles
• B. Windpipe
• C. Bronchi
• D. Alveoli✓

Explanation: Alveoli are tiny air sacs in your lungs that take up the oxygen you breathe in and keep your body going. Although they're microscopic, alveoli are the workhorses of your respiratory system. People have an average of 480 million alveoli in their lungs, located at the end of bronchial tubes.

Q64. Which of the following structure primarily helps in attachment of bacteria on various surfaces?

• A. Pilli✓
• B. Flagella
• C. Both A and B
• D. None of these

Explanation: Flagella help in locomotion whereas pilli help in attachment.

Q65. A chemical component that is NOT found in all viruses is _.

• A. Protein
• B. Lipids✓
• C. DNA
• D. RNA

Explanation: Lipid envelope is the chracteristic of only some viruses, who also gain it by their host cells after they cause it to burst. The only necessary features in all viruses are protien coat and nucleic acids.

Q66. Sperms are produced in:

• A. Urethra
• B. Sperm dust
• C. Pancreas
• D. Testes✓

Explanation: Explanation for this question will be added soon.

Q67. What does ATP provide during photosynthesis?

• A. Mechanical energy
• B. Physical energy
• C. Chemical energy✓
• D. All of these

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

Q68. The wishbone of birds comes from the

• A. pelvic girdle
• B. skull
• C. hind limbs
• D. pectoral girdle/clavicles.✓

Explanation: The wishbone, known in anatomy as the furcula, is a sternum bone found in birds which is shaped like the letter Y. It is used as an attachment point for the wing muscles. It is so named because of a tradition:Two people pull on each side of such a bone, and when it breaks, the one who gets the larger part is said to have a wish granted. The fork shaped bone is formed from wo clavicles fused with the inter clavicle.

Q69. It length of myofibril from one Z-line to the next:

• A. Plasma membrane
• B. Sarcomere✓
• C. Sarcoplasm
• D. Sarcolemma

Explanation: The length of myofibril from one Z-line to the next is known as sarcomere

Q70. Antibodies are manufactured in:

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

Explanation: Option D is correct.Antibodies are manufactured in B lymphocytes. B lymphocytes are a type of white blood cell that are responsible for the body's humoral immune response. The humoral immune response is the part of the immune system that fights off infection by producing antibodies. Antibodies are proteins that bind to specific antigens, which are molecules found on the surface of foreign invaders. When an antibody binds to an antigen, it triggers a cascade of events that ultimately leads to the destruction of the foreign invader. B lymphocytes are produced in the bone marrow. When a B lymphocyte encounters an antigen for the first time, it becomes activated. The activated B lymphocyte then divides and produces a clone of cells that all produce the same antibody. These cells are called plasma cells. Plasma cells secrete antibodies into the blood and lymph fluid.

Q71. 50 secondary spermatocytes and 50 secondary oocytes will give rise to

• A. 50 sperms and 50 ova
• B. 100 sperms and 50 ova✓
• C. 200 sperms and 50 ova
• D. 50 sperms and 100 ova

Explanation: Each secondary spermatocyte gives rise to 2 sperm and each secondary oocyte gives rise to 1 ova and 1 polar body. The polar body is ruptured and is used as a source of nutrition, so only one ova is produced by 1 secondary oocyte. In short, each secondary spermatocyte will produce 2 sperms so 50 secondary spermatocytes will produce 100 sperms (2*50). At the same time, each secondary oocyte will give only one Ova so 50 secondary oocytes = 50 ova.

Q72. The genotypes of a husband and wife are IAIB and IAi. Among the blood types of their children, how many different genotypes and phenotypes are possible?

• A. 3 genotypes; 4 phenotypes
• B. 4 genotypes; 3 phenotypes✓
• C. 4 genotypes; 4 phenotypes
• D. 3 genotypes; 3 phenotypes

Explanation: If the genotypes of husband and wife are IAIB and IAi respectively, then the probabilities of genotypes and phenotypes among their children can be worked out as:Genotype: IAIA IAi IAIB IBiPhenotype: A A AB BThus, there are four possible genotypes, IAIA, IAi, IAIB, and IBi, and three possible phenotypes, A, AB, and B among the children.

Q73. The partial pressure of oxygen in the alveoli of the lungs is

• A. equal to that in the blood
• B. more than that in the blood✓
• C. less than that in the blood
• D. less than that of carbon dioxide.

Explanation: (b) : The partial pressure of oxygen in alveolar air is 104mmHg whereas it is 40mmHg in deoxygenated blood and 95mm Hg in oxygenated blood.

Q74. Name the pulmonary disease in which alveolar surface area involved in gas exchange is drastically reduced due to damage in the alveolar walls.

• A. Pneumonia
• B. Asthma
• C. Pleurisy
• D. Emphysema✓

Explanation: (d) :Emphysemais an inflation or abnormal distension of the bronchioles or alveolar sacs of the lungs. Many of the septa between the alveoli are destroyed and much of the elastic tissue of the lungs is replaced by connective tissue. As the alveolar septa collapse, the surface area for gas exchange is greatly reduced. There is loss of elasticity in the walls of bronchioles or alveolar sacs. As a result the alveolar sacs remain filled with air even after expiration. The exhalation becomes more difficult. The lungs remain inflated. Major causes of emphysema are cigarette smoking and the inhalation of smoke or other toxic substances over a period of time.

Q75. Lipid bilayer makes the membrane differently permeable barrier that allows the transport of

• A. lonic materials
• B. Polar materials
• C. Non-polar materials✓
• D. Glycoproteins

Explanation: Lipids,proteins and carbohydrates are responsible for functional diversity of the membranes. Lipid bilayer makes the membrane differentially permeable barrier that allows the transport of non-polar materials across it and prevents ionic materials.

Q76. _ enzyme needs a primer for the initiation of its function

• A. RNA polymerase
• B. DNA polymerase✓
• C. Primase
• D. Ligase

Explanation: The synthesis of a primer is necessary because DNA polymerases, can only attach new DNA nucleotides to an existing strand of nucleotides. The primer therefore serves to prime and lay a foundation for DNA synthesis.

Q77. Male having Downs syndrome have sex chromosomes:

• A. XXY
• B. XY✓
• C. XYY
• D. XYYY

Explanation: In Down’s syndrome , the affected person contains an extra autosomal chromosome number 21 (trisomy 2n+1). Male having this syndrome have XY sex chromosomes. They have 3 21st chromosome.

Q78. In nitrogen fixing bacteria, the nitrogenase complex is sensitive to:

• A. O2✓
• B. CO2
• C. NO2
• D. NO3

Explanation: Nitrogen fixing bacteria contain an enzyme complex known as Nitrogenase which catalyses the conversion of nitrogen gas to ammonia. The nitrogenase complex is sensitive to oxygen. Oxygen will make the enzyme irreversibly inactive. So, the nitrogen-fixing bacteria needs to protect the nitrogenase enzyme from oxygen.

Q79. An autoimmune disorders in which stiffness and inflammation of vertebrae occurs is called as:

• A. Lupus
• B. Scleroderma
• C. Ankylosis spondylotis✓
• D. Juvenile dermatomyositis

Explanation: An autoimmune disorder in which stiffness and inflammation of vertebrae occur is called Ankylosis spondylitis.

Q80. Common name of the Loligo pealeii is:

• A. Squid✓
• B. Laligo
• C. Slug
• D. Oyster

Explanation: Squid is the common name of Loligo pealeii.

Q81. Piriformis syndrome is associated with which of the following disorder:

• A. Arthritis
• B. Sciatica✓
• C. Spondylosis
• D. Disc slip

Explanation: Sciatica refers to pain, weakness, numbness, or tingling in the leg. It is caused by injury to or pressure on the sciatic nerve. The sciatic nerve starts in the lower spine and runs down the back of each leg.Common causes of sciatica include; slipped disc, piriformis syndrome (a pain disorder involving the narrow muscle in the buttocks), pelvic injury or fracture, and tumors.

Q82. For which purpose myeloma cells (cancerous B.lymphocytes) are used in the production of monoclonal antibodies?

• A. Increased rate of cell division
• B. Immunization with antigen✓
• C. To avoid contamination
• D. As nutrient in media

Explanation: Multiple myeloma cells are abnormal plasma cells (a type of white blood cell) that build up in the bone marrow and form tumors in many bones of the body. They are produced for immunization with antigen as Vaccines contain weakened or inactive parts of a particular organism (antigen) that triggers an immune response within the body.

Q83. If medulla oblongata of a person brain is damaged which of the following process will be disturbed?

• A. Thinking
• B. Sleep
• C. Thirst
• D. Swallowing✓

Explanation: Medulla oblongata is the structure found in the human brain. The major function of Medulla oblongata is to control automatic function (that is not in human control) breathing, respiration, and heartbeat. It also helps in body secretion, reflexes, swallowing, coughing and sneezing actions.

Q84. The experiments by Hershey and Chase helped confirm that DNA was the hereditary material on the basis of the finding that :

• A. Radioactive phage were found in the pellet
• B. Radioactive cells were found in the supernatant
• C. Radioactive sulfur was found inside the cell
• D. Radioactive phosphorus was found in the cell✓

Explanation: The experiments by Hershey and Chase helped confirm that DNA was the hereditary material as radioactive phosphorus was found in the cell.The Hershey-Chase experiments were not the first studies to oppose the prevailing theory in the early 1900s that genetic material was composed of proteins. In 1944, nearly a decade before Hershey and Chase’s work, scientists published sound evidence that genes were made of DNA rather than protein so it was confirmed by presence of phosphorus.

Q85. If one of the following components is missing , bacteria can not increase the number of its plasmid copies.

• A. Antibiotic resistance gene
• B. Origin of replication✓
• C. Cloning site
• D. Ligases enzymes

Explanation: An essential feature of bacterial plasmids is their ability to replicate as autonomous genetic elements in a controlled way within the host. Therefore, they can be used to explore the mechanisms involved in DNA replication and to analyze the different strategies that couple DNA replication to other critical events in the cell cycle therefore they can replicate to increase the number of plasmid.

Q86. If in solution some bacteria infected by a certain phages had somehow developed the ability to make a particular amino acid that was not in their genes before. What would be the possible explanation to his new ability ?

• A. Induction
• B. Transformation
• C. Transduction✓
• D. Conjugation

Explanation: Transduction is the process by which a virus transfers genetic material from one bacterium to another. Viruses called bacteriophages are able to infect bacterial cells and use them as hosts to make more viruses with new genes.

Q87. Which one of the following is the correct oxidation state of Mn in KMnO4?

• A. -6
• B. 7✓
• C. 9
• D. 10

Explanation: Since the oxidation state of potassium and oxygen are +1 & -2 respectively. So, KMnO4 1 + Mn + 4(-2) =0 1 + Mn - 8 = 0 Mn - 7 = 0 And Mn = 7 Thus, oxidation state of Mn is +7 in KMnO4.

Q88. Quantum number which describes the orientation of orbitals in three dimensional space is

• A. Spin quantum number
• B. Azimuthal quantum number
• C. Magnetic quantum number✓
• D. Principal quantum number

Explanation: Magnetic Quantum Number (m) : Gives the orientation of the orbital in space; in other words, the value of m describes whether an orbital lies along the x-, y-, or z-axis on a three-dimensional graph, with the nucleus of the atom at the origin. m can take on any value from −ltol. Hence option C is correct.

Q89. Substance that has sharp melting point in the following is:

• A. Gemstone
• B. Coal tar
• C. Glass
• D. Diamond✓

Explanation: Each carbon atom is covalently bonded to four other carbon atoms in diamond. A lot of energy is needed to separate the atoms. This is because covalent bonds are strong. This is the reason why diamond has a high melting point.

Q90. Which of the following pairs is an example of completely immiscible liquids?

• A. Alcohol and water
• B. Alcohol and ether
• C. Water and ether
• D. Carbon disulphide and water✓

Explanation: CS2 Insoluble in water and more dense (10.5 lb / gal) than water. Hence sinks in water.

Q91. The number of isomers of pentane is

• A. 2
• B. 4
• C. 5
• D. 3✓

Explanation: Pentane (C5H12) is an organic compound with five carbon atoms. Pentane has three isomers that are n-pentane, Iso-pentane (methyl butane) and neopentane (dimethylpropane). Therefore three isomers can be drawn from pentane.

Q92. The compound which has the higher boiling point in the following is

• A. Methyl chloride
• B. Methyl iodide✓
• C. Methyl bromide
• D. Both a and b

Explanation: For the same alkyl group the boiling points of haloalkanes are in the order RCl < RBr < RI, because with the increase in the size of halogen atom the magnitude of van der Waal forces of attraction increases. Hence the order of boiling points is Methyl chloride (CH3Cl) < methyl bromide (CH3Br) < methyl iodide (CH3I).

Q93. Which one of the following is addition polymer

• A. Nylon
• B. PVC
• C. Polythene
• D. Both PVC and Polythene✓

Explanation: In addition polymerization (sometimes called chain-growth polymerization), a chain reaction adds new monomer units to the growing polymer molecule one at a time through double or triple bonds in the monomerOn the other hand, condensation polymerization is a process that involves repeated condensation reactions between tri-functional or bi-functional monomers with elimination of small molecules.

Q94. Which one is more reactive

• A. HCHO✓
• B. CH3 CHO
• C. (CH3)2CO
• D. Hace equal reactivity

Explanation: Aldehydes are usually more reactive toward nucleophilic substitutions than ketones because of both steric and electronic effects. In aldehydes, the relatively small hydrogen atom is attached to one side of the carbonyl group, while a larger R group is affixed to the other side. In ketones, however, R groups are attached to both sides of the carbonyl group. Thus, steric hindrance is less in aldehydes than in ketones. Electronically, aldehydes have only one R group to supply electrons toward the partially positive carbonyl carbon, while ketones have two electron‐supplying groups attached to the carbonyl carbon. The greater amount of electrons being supplied to the carbonyl carbon, the less the partial positive charge on this atom and the weaker it will become as a nucleus.

Q95. For exothermic reversible reaction activation energy for forward direction depends upon

• A. Temperature
• B. Nature of reactant✓
• C. Nature of product
• D. Both Temperature and Nature of reactant

Explanation: For exothermic reversible reaction activation energy for forward direction depends upon nature of reactant.

Q96. As the polarizing power of cation increases thermal stability of carbonates

• A. Increases
• B. Decreases✓
• C. Not dependent
• D. Depends upon pressure

Explanation: As the polarizing power of the cation increases, it polarizes the carbonate (anion). The nucleus of the cation attracts electrons of anion causing a decrease in its thermal stability.

Q97. Which ions are used as catalyst in the reaction between persulfate ions and iodide ions?

• A. Lead
• B. Iron✓
• C. Copper
• D. Chromium

Explanation: Fe 2+ and Fe3+ ions are used as catalysts in this reaction since both the reactants are negatively charged, they repel each other, leading to a high activation energy

Q98. Which one is stronger nucleophile?

• A. C2H5O
• B. C2H5S✓
• C. Both are equally strong
• D. None of the above

Explanation: C2H5S- is the stronger nucleophile due to the positive inductive effect from the alkyl group and since sulfur has more electrons than oxygen, it is attracted toward the center of a positive charge.

Q99. C4H11N gives the type of isomerism

• A. Metamerism✓
• B. Optical isomerism
• C. Tautomerism
• D. None

Explanation: It gives metamerism which is when compounds having the same molecular formula but different alkyl groups on either side of functional groups

Q100. Hydration of hydrocarbon give carbonyl compound, the general formula of that hydrocarbon is

• A. CnH2n+2
• B. CnH2n
• C. CnH2n-2✓
• D. Both CnH2n and CnH2n-2

Explanation: Alkynes on hydration in presence of H2SO4 and HgSO4 yield carbonyl compound through enol All alkynes except ethyne give ketones while ethyne gives aldehyde.

Q101. Consider reversibility in free radical substitution reaction of alkane then Kc value is smallest for

• A. Initiation step
• B. Propagation step
• C. Termination step✓
• D. All same

Explanation: The Kc is smallest for termination step as in this step two radicals join together to form a species and the reversible reaction is not highly favored. Termination step Kc = [ CH3Cl] /[CH3°] [Cl°] Kc <1 Thus termination step has smallest Kc.

Q102. SiO2 is the only oxide that reacts with:

• A. HClaq
• B. KOHaq✓
• C. Steam
• D. SO3

Explanation: KOH(aq)- Silicon dioxide is acidic but will only react with strong bases of hot concentrated KOH/NaOH due to its strong and extensive covalent bonds.

Q103. Students were heating CaCO3 in an open container to produce CO2 gas, CaCO3(s) ⟶ CaO(s) + CO2(g) If we increase pressure on this system the:

• A. Equilibrium will shift towards right
• B. Equilibrium will shift towards left
• C. Equilibrium will not be disturbed
• D. System does not obey equilibrium rules✓

Explanation: Chemical equilibrium is the state in which both reactants and products are present in concentrations that have no further tendency to change with time. It is attained in a closed system. A closed system is one in which nothing new is added to a system and nothing is removed from a system. This means concentration will not change with time and the system will remain in equilibrium. Hence, there cannot be chemical equilibrium in an open system as mass and heat escapes from the open system can not be used reversibly and there is no fixed mass in an open system.

Q104. Initially one mole each N2 and O2 were made to react as,If at equilibrium 0 ∙ 25 moles of O2 is present the equilibrium concentration of NO will be:

• A. 0.50 moles
• B. 0.125 moles
• C. 1.50 moles✓
• D. 1.75 moles

Explanation: N2(g) + O2(g) 2NO(g) As from the balance chemical equation it is clear that 1 mole O2 gives 2 mole NO so as 0.25 mole O2 left so 0.75 mole consumed so it will give 1.50 mole NO. 2x0.75-1=1.50

Q105. The type of isomerism present in the compound given, is:

• A. Structural
• B. Optical
• C. Stereo✓
• D. None of the above

Explanation: Stereoisomers are isomers that have the same composition (that is, the same parts) but that differ in the orientation of those parts in space. There are two kinds of stereoisomers: enantiomers and diastereomers. The two conditions must be met for compounds to show Stereoisomerism(geometric isomerism) 1- There should be a C-C double bond to restrict free rotation of attached groups. 2- The two groups attached to the same C must be different.

Q106. The volume of 𝐶𝑂2 produced by heating 33.5𝑔 𝐿𝑖2𝐶𝑂3 at room temperature and atmospheric pressure is (𝑀𝑟 𝐿𝑖2𝐶𝑂3 = 67𝑔/𝑚𝑜𝑙):

• A. 22.4 𝑑𝑚3
• B. 12.0 𝑑𝑚3✓
• C. 11.2 𝑑𝑚3
• D. 24.0 𝑑𝑚3

Explanation: moles of Li2CO3= mass/Mr =33.5/67 = 0.5 Moles of CO2: moles of Li2CO3 1 : 1 Hence moles of CO2 =0.5 0.5 × 24= 12dm3 Molar volume at ROOM temperature and pressure is 12 dm³ while molar volume at STANDARD temperature and pressure is 22.4 dm³.

Q107. The compound which can form hydrogen bond with water is:

• A. CH3–O-CH3
• B. CH3 –CH2 –OH✓
• C. CH3 –CH2–NH2
• D. None of the above.

Explanation: Option B contains OH that can interact with the water to form a hydrogen bond with water. Hydrogen bonding occurs when hydrogen has a covalent bond to an atom that is more electronegative than it. The more electronegative atom pulls the shared electrons unequally towards it, creating a polar bond.

Q108. Choose the molecule that could not be represented by single electronic structure formula:

• A. CH4
• B. H2O
• C. SO2✓
• D. O2

Explanation: C is the correct option as the electronic structure of the SO2 molecule is best represented as a resonance hybrid of two equivalent structures

Q109. 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.

Q110. Stable electronic configuration of Cu(29) is:

• A. [Ar] 4S2 3d4
• B. [Ar] 4S0 3d10
• C. [Ar] 4S1 3d10✓
• D. [Ar] 4S2 3d7 4p2

Explanation: It is a transition element. Copper (Cu) is a chemical element, a reddish, extremely ductile metal of Group 11 (IB) of the periodic table that is an unusually good conductor of electricity and heat. Due to the interelectronic repulsions one electron present in 4s enters to 3d subshell. We can write a stable electronic configuration of copper is written as 1s22s22p63s23p63d104s1. There is additional stability because of the completely occupied 3d subshell and half-filled 4s subshell.orThe electronic configurations of copper (and chromium) are unique since without filling the 4s orbitals, electrons entered into 3-d orbitals. Copper has an atomic number of 29 hence 29 electrons are fulfilled by option C as well.

Q111. The proton acceptor is:

• A. NH3✓
• B. BF3
• C. HCl
• D. H+

Explanation: Weak Bronsted bases which are proton acceptors, usually consist of molecules or ions. They react with water, remove a proton from it, and generate OH- ions. Take the examples of NH3: NH3(aq) + H2O(aq) ---> NH4+(aq) + OH- (aq)

Q112. Select alkene of the following hydrocarbons:

• A. C5 H22
• B. C5 H10✓
• C. C5 H8
• D. C4 H10

Explanation: The general formula for alkenes is CnH2n, where n=5 is the formula for alkene C5H10

Q113. The oxidation state of carbon in Na2C2 is:

• A. +4
• B. +2
• C. –1✓
• D. –4

Explanation: We know that the charge of Na is always +1, and the overall charge on the Na2C2 molecule is 0. We can equate this to form2(+1) + 2x = 02x = -2x(Charge on C) = -1

Q114. Choose atom that having spin quantum number ½

• A. 12C
• B. 15N✓
• C. 16O
• D. 32S

Explanation: The spin is a quality of particles, it tells us the angular momentum (½) of an electron of a substance. Since momentum is a vector quantity, the spin quantum number can be both positive and negative. This question asks which atom has a ½ spin number, the positive and negative spins of atoms with an even number of electrons will cancel out, thus only an atom with an odd number of electrons has a spin of ½ which is B.

Q115. A tertiary carbon is bonded directly to:

• A. 2 Hydrogens
• B. 2 Carbons
• C. 3 Carbons✓
• D. 4 Carbons

Explanation: A tertiary carbon by definition is a carbon that is bonded to 3 other carbons.

Q116. Which of the following compounds will react with methyl magnesium Iodide followed by acid hydrolysis to give ethyl alcohol?

• A. Ethylene
• B. Acetone
• C. Acetaldehyde
• D. Formaldehyde✓

Explanation: The reaction of methylmagnesium iodide with formaldehyde followed by hydrolysis with aqueous acid yields ethyl alcohol.

Q117. 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.

Q118. 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

Q119. 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.

Q120. 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

Q121. 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.

Q122. 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.

Q123. Hydrogen bonding do not exist in the molecule of:

• A. Hydrogen✓
• B. Proteins
• C. Carbohydrates
• D. Ammonia

Explanation: 2 H bonded together contain only London dipole forces of attraction as Hydrogen bonding only occurs with strong electronegative atoms like Fluorine, Oxygen and Nitrogen (NOF rule)

Q124. Which statement is incorrect about ionization energy?

• A. Ionization energy depends upon the magnitude of nuclear charge
• B. Ionization energy depends upon the atomic radius
• C. Ionization energy depends upon the shielding effect
• D. Ionization energy does not depend upon the penetration effect of the inner orbital✓

Explanation: Option D is incorrect because the penetration effect refers to the ability of inner orbital electrons to occupy the same space as outer electrons, leading to increased electron-electron repulsion and higher ionization energy.

Q125. Rain water becomes acidic, when the pH-value of rain water becomes _

• A. Greater than 6
• B. Greater than 6.5
• C. Less than 5.6
• D. Less than 5✓

Explanation: Normal clean rain has a pH value between 5.0 - 5.5, which is slightly acidic, however when rain combines with nitrogen oxides or SO2, it becomes more acidic has the pH drops below 5.0. Therefore the answer is D.

Q126. How many molecules are present in 0.20 g of Hydrogen gas? Select the correct option.

• A. 0.20 x 3.01 x 1023✓
• B. 0.20 x 2.016
• C. 0.70 x 6.02 x 1023
• D. 1.008 x 6.02 x 1023

Explanation: One gram of hydrogen contains one mole of hydrogen as its atomic weight is 1, one mole is 6.02 x 1023 atoms. Since hydrogen is diatomic the amount of molecules would be 3.01 x 1023, therefore the answer would be 3.01 x 1023, which will then be multiplied by 0.20.

Q127. 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.

Q128. 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.

Q129. 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.

Q130. 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°.

Q131. Which is the correct product formed when monohydric alcohol reacts with sodium metal?

• A. Alkene
• B. Sodum alkoxide✓
• C. Alkane
• D. Ether

Explanation: When alcohols react with metals a salt is formed,the reaction when a monohydric alcohol reacts with sodium metal results in the production of sodium alkoxide and hydrogen gas, hence the answer is B.

Q132. Thermal processing of industrial waste material aims at:

• A. Burning of waste material in pits
• B. Converting the solid waste into useful products by thermal treatment✓
• C. Energy recovery from organic matter prior to its final disposal
• D. Size reduction and compaction by thermal process

Explanation: The primary function of thermal treatment is to convert the waste to a stable and usable end product. Therefore the answer will be B.

Q133. Which of the following titrants would most likely be used as ths‘ own indicator in acid medium?

• A. K2Cr2O3
• B. Iodine
• C. KMnO4✓
• D. H2O2

Explanation: KMnO4 acts as an oxidising agent in acidic mediums only.

Q134. Chlorosis is caused by the deficiency of:

• A. Magnesium✓
• B. Iron
• C. Phosphorus
• D. Potassium

Explanation: Chlorosis is typically caused when leaves do not have enough nutrients to synthesise all the chlorophyll they need. It can be brought about by a combination of factors including: a specific mineral deficiency in the soil of Mg2+

Q135. How many different values can m, assume in the electron sub-shell designated by quantum number n=5, l=4?

• A. 4
• B. 5
• C. 6
• D. 9✓

Explanation: 'n' is referred to as the principal quantum number and 'l' is the azimuthal quantum number. l=4 means the azimuthal quantum number is associated with 5g. Since 'g' has 9 subshells 'm' will be -4, -3, -2, -1, 0, +1, +2, +3, +4.

Q136. Which one of the following salts will produce an alkaline solution when dissolved in water?

• A. NH4CI
• B. NaNO3
• C. Na2CO3✓
• D. Na2SO4

Explanation: Na2CO3 will form an alkaline solution because its formed by the reaction of a strong base NaOH and a weak acid H2CO3. Therefore the answer will be C.

Q137. Which one of the following compounds will show covalent bonding?

• A. CaF2
• B. MgO
• C. KCI
• D. H2✓

Explanation: Covalent bond is a chemical bond that involves the sharing of electrons,options A, B and C all show ionic bonds, therefore the correct answer will be D.

Q138. You are required to test the presence of NH4+ Ion in water. Which of the following reagent will solve your problem?

• A. Imethylglyoxime
• B. Tollen‘s reagent
• C. Nessler‘s reagent✓
• D. Magneson reagen

Explanation: Nessler’s reagent can be used to detect the presence of NH4+ ions in water as brown ppt is formed. Therefore the correct answer will be C.

Q139. Ethylene diamine tetra acetate ion (EDTA) is a polydentate ligand, it bonds to central metal atom through:

• A. Two of its atoms
• B. Three of its atoms
• C. Four of its atoms
• D. Six of its atoms✓

Explanation: When this ion bonds to a metal atom, the two N atoms, and four of the O atoms, are used. In this complex, a single EDTA4- ion forms 6 bonds to the Fe atom (i.e., 2 Fe-N bonds and 4 Fe-O bonds). The coordination number of 6 results in an octahedral structure.

Q140. Given the reaction: C3H6 + 5O2 → 3CO2 + 4H2O At STP, how many litres of O2 are needed to completely burn 5.0 litres of C3H6?

• A. 5
• B. 10
• C. 10.5
• D. 15
• E. 25✓

Explanation: Consider that no. of moles of reactants = the volume of the reactants. As the molar ratio between C3H6 and O2 is 1:5, the volume ratio is also the same. For 1L of C3H6 we need 5L of O2. Since the volume of C3H6 is 5L now, to burn this, we require 25L of O2. All other options are incorrect because they do not follow the exact mole-volume relationship required in this case.

Q141. Law of Conservation of Momentum states that total linear momentum of system remains constant if:

• A. Balanced external forces are applied to a system.
• B. No external force is applied to a system.✓
• C. Only linear force is applied in a system is zero.
• D. Sum of external forces are applied to a system is zero.

Explanation: This is a statement of the conservation of linear momentum, thus, it is a fact. For the sake of explanation, an external force would disturb the equilibrium of the system and produce an acceleration in the objects being tested.

Q142. In an inelastic collision, Momentum is _ and Kinetic Energy is _ respectively.

• A. Not conserved ; not conserved
• B. conserved ; not conserved✓
• C. Conserved ; conserved
• D. Not conserved ; conserved

Explanation: B is the answer as momentum is always conserved in a closed system however if we talk about the kinetic energy, it isn’t conserved as it is converted to other forms of energy hence the overall energy is conserved but kinetic energy, solely, isn’t.

Q143. A bullet of mass 20g leaves the gun with a velocity of 200 m/s. If the mass of gun is 2kg then the speed of recoil of the gun is:

• A. 2000 m/s
• B. 2 m/s✓
• C. 20 m/s
• D. 200 m/s
• E. 100 m/s

Explanation: The principle of conservation of momentum states that the total momentum of an isolated system remains constant. Here, the gun and the bullet together form a system. So, the momentum of the gun and the bullet before firing will be equal to the momentum of the gun and the bullet after firing. Initial momentum = Final momentum (mass of gun) x (velocity of gun) = (mass of bullet) x (velocity of bullet) + (mass of gun) x (velocity of recoil) Substituting the values, we get: (2 kg) x 0 m/s = (0.02 kg) x (200 m/s) + (2 kg) x (velocity of recoil) Solving for the velocity of recoil, we get: velocity of recoil = - (0.02 kg) x (200 m/s) / (2 kg) = -2 m/s The negative sign indicates that the recoil is in the opposite direction to the direction of the bullet. So, the magnitude of the speed of the recoil of the gun is 2 m/s.

Q144. A car at rest starts moving with linear uniformly increasing velocity. After 20 seconds, it attains the maximum velocity of 80 m/s. What is the distance covered during this time interval?

• A. 200 m
• B. 400 m
• C. 800 m✓
• D. 1600 m

Explanation: The acceleration of the car is constant as it undergoes uniformly increasing velocity. Let the initial velocity of the car be u = 0 m/s, and final velocity be v = 80 m/s. The time taken to achieve this velocity is t = 20 s.Using the formula for uniformly accelerated motion, we have:v = u + atwhere a is the acceleration. Rearranging the equation, we get:a = (v - u)/t = 80 m/s / 20 s = 4 m/s2To find the distance covered by the car during the given time interval, we use the formula:s = ut + (1/2)at2where s is the distance traveled. Substituting the given values, we get:s = (1/2)(4 m/s2)(20 s)2 = 800 mTherefore, the correct answer is C) 800 m.

Q145. An object is thrown vertically upward with a velocity of 20 m/s. How much time it will take to reach the highest point?

• A. 2 sec✓
• B. 4 sec
• C. 1 sec
• D. Insufficient information

Explanation: The body is thrown vertically upwards with velocity of 20 m/s , it means initial velocity is 20 m/s. And if it is thrown upwards it will come to rest, So, final velocity is 0 m/s. The gravitational force is applied in the opposite direction of motion, so we will take acceleration as - 10 m/s². Using first equation of motion:

Q146. An object is falling down with a speed of 20 m/s. After 3 seconds its velocity will be _ m/s (g = 10 m/s2).

• A. 05
• B. 50✓
• C. 55
• D. 95

Explanation: v=u+atv=20+10(3)v=20+30=50 m/s.Hence B.

Q147. A paratrooper is falling down with uniform velocity and also rotating with a constant angular velocity of 0.2 rad/sec. The body satisfies _.

• A. The first condition of equilibrium but not second
• B. Second condition of equilibrium but not first
• C. The first and second conditions of equilibrium✓
• D. Neither the first nor the second condition of equilibrium

Explanation: First condition of equilibrium: The condition states that a body will be in equilibrium if the resultant of all the forces acting on it is zero. Sindh Textbook for Class XI P145 Second condition of equilibrium: The body is said to be in rotational equilibrium, if the vector sum of the torques acting on it is zero. This is second condition of equilibrium Sindh Textbook for Class XI P149 Body satisfies the first and second law of equilibrium. The first law states that for an object to be in equilibrium forces acting on it must be equal and opposite, since the paratrooper is falling with a uniform velocity, this means this is true. The angular velocity is also constant, which implies that torque acting on the paratrooper clockwise is equal to the torque acting anticlockwise.

Q148. A car of mass 1200 kg initially at rest has been accelerated to a speed of 8 m/s in 16 meters. Average acceleration of the car is _ m/s2? And force is _ N?

• A. 1.5 and 1500
• B. 2.5 and 2400
• C. 3.5 and 3500
• D. 2 and 2400✓

Explanation: m=1200kg v=8m/s d=16m v2=u2+2as (8)2=(0)2+2(a)(16) 64=32a a=2m/s2 F = ma = 1200×2 =2400N

Q149. A car starts from rest and moves with constant acceleration. During the 4th second of its motion, it covers a distance of 21 meters. The acceleration of the car is _ m.

• A. 04
• B. 06✓
• C. 08
• D. 16

Explanation: Formula for nth second: Sn= u + ½ a (2n-1) initial velocity, u, is taken as zero as, according to the question, the car starts from rest. n=nth second a= acceleration produced S= distance covered 21=0 + ½ × a× (2×4 -1) 21= ½ × a× (2×4 -1) 21= ½ × a× (8 -1) 21= ½ × a× 7 21= 7/2 a 21×2 = 7a 42/7 = a 6= a Acceleration (a) produced by the car = 6 ms‐² P.s. in the question acceleration unit is m. It should be m/s²

Q150. A wire of resistance 4 is bent into a circle. The resistance between the ends of a diameter of the circle is:

• A. 4Ω
• B. 1 Ω✓
• C. 1/4 Ω
• D. 1/16 Ω

Explanation: When a wire of resistance 4R is bent in the form of circle, then the resistance of each segment across the diameter becomes 2R. Equivalent resistance between A and B: +1/Rb (in parallel combination) ∴ 1/RAB = 1/(2R) +1/(2R) 1/RAB = 2/(2R) ⟹ RAB=R Here is the link from where you understand this MCQ:

Q151. The state of thermal equllibrium between two systems is determined by equality of:

• A. Pressure
• B. Volume
• C. Temperature✓
• D. Mass

Explanation: Thermal equilibrium occurs when two bodies are in contact with each other and can freely exchange energy which occurs when they have the same temperature.The state of equilibrium between two systems is determined by the balance of forces or factors that influence each system, ensuring that there is no net change or movement between them. This can involve factors like pressure, temperature, concentration, and more, depending on the specific context of the systems in question.

Q152. Half cell reaction standard reduction potential, Eo= Fe2+ 2e- → Fe –0.41Cu2+ 2e- → Cu 0.34 Ni2+ 2e- → Ni -0.25 Zn2+ 2e- → Zn -0.76Referring to the table above which metal could be used to prevent iron from corrosion?

• A. Cu only
• B. Zn only✓
• C. Cu & Ni only
• D. Ni and Zn only

Explanation: Zn is the only element in the table which has its E0 value more negative then Iron, hence it will prevent iron from corroding by forming a layer of zinc carbonate.

Q153. 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.

Q154. 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.

Q155. 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

Q156. 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

Q157. 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.

Q158. For transformer, if Ns/Nr = 2 : 1 then Ip/Is =

• A. 1:2
• B. 2:1✓
• C. 4:1
• D. 1:1

Explanation: Explanation is given below:

Q159. Astronomers calculate speed of distant stars and galaxies using which of the following phenomena:

• A. Beats
• B. Interference
• C. Superposition principle
• D. Doppler effect✓

Explanation: Astronomers can measure the rotation speed in spiral galaxies by obtaining spectra of either stars or gas, and looking for wavelength shifts produced by the Doppler effect. Remember that the faster something is moving toward or away from us, the greater the shift of the lines in its spectrum.

Q160. In a full-wave bridge rectification, the number of diodes used are:

• A. 1
• B. 2
• C. 3
• D. 4✓

Explanation: The full-wave rectifier circuit consists of 4 diodes arranged in a tetrahedral connection. When we have the upper side of the AC supply as positive, the current flows through D1 to the load and returns through D2 at the temporary negative terminal of the AC supply. When the bottom side of the AC supply is positive, due to the constant change in polarity, the current, conventionally, flows through D3 to the load and returns to the supply by passing through D4. It reaches the supply at the now negative terminal of the AC supply which is the upper side of the supply.

Q161. The number of diodes in bridge rectifier is

• A. 4✓
• B. 3
• C. 2
• D. 5

Explanation: It is a fact that a bridge rectifier has 4 diodes. It is also called a full wave rectifier.

Q162. What is the instantaneous power dissipated through a resistor of resistance 10 ohm if it is connected to an AC source of frequency 15 Hz at 1/180 sec if peak value is 20 V?

• A. 10 W✓
• B. 100 W
• C. 40 W
• D. Cannot be determined

Explanation: UsingVo = V sin(2𝜋ft) = 20 x sin (2𝜋 x 15 x 1/180) = 10 VUsingP = v2/ R = 102 / 10 = 10 W

Q163. Which one of the following is not electromagnetic in nature.

• A. X-rays
• B. Gamma rays
• C. Cathode rays✓
• D. Infrared rays

Explanation: Cathode ray is made up of electrons, so it is not an electromagnetic wave. They are deflected neither by the electric field nor by the magnetic field.

Q164. Which of the following has zero average value in a plane electromagnetic wave:

• A. kinetic energy
• B. magnetic field
• C. electric field
• D. both (b) and (c)✓

Explanation: In an electromagnetic wave, the average value of the electric field or magnetic field is zero, because electromagnetic waves are sinusoids and the average of a sinusoid over 1 period is zero.

Q165. A current carrying solenoid is cut into a ratio 1:3 such that both are independently connected with the same source of current. Now if the magnetic field of the first part is “BA” while the second part respectively is “BB” then what is true?

• A. BA=3BB
• B. BA=(BB)/3
• C. BA=BB✓
• D. BA=4BB

Explanation: Magnetic field in solenoid is independent of length and cross section area; B= 𝛍 nI n=I/L n= number of turns I=current L=length B magnetic flux density 𝛍= magnetic Constant Even if solenoid is cut in any ratio; n would still remain the same because magnetic field in solenoid is independent of length and cross section area .If n remains same so will be the magnetic field

Q166. The region that lies between IR and UV regions is called:

• A. Radio waves
• B. None of these
• C. X ray region
• D. Visible light✓
• E. All of these

Explanation: The visible light region falls between the ultraviolet (UV) and infrared (IR) regions on the electromagnetic spectrum. The UV region has a wavelength in the range of 100-400 nm whereas the IR region has a wavelength in the range of 760-1 million nm. The narrow range of 400-700 nm represents rays in the visible light range; rays of wavelengths visible to the human eye.

Q167. Magnetic force on a charged particle is:

• A. QvBl
• B. None of these
• C. QvB cosθ
• D. QvB sinθ✓

Explanation: When a charge moves through a magnetic field, a force is applied on it which is given by:F = QvB sinθQvBl is the motional EMF produced when a conductor moves through a static magnetic field.

Q168. An electron is moving along the axis of a solenoid carrying a current. Which of the following is a correct statement about the magnetic force acting on the electron?

• A. The force acts radially inwards
• B. The force acts radially downwards
• C. The force acts in the direction of motion
• D. No force acts✓

Explanation: The electron will be accelerated along the axis The electron path will be circular about the axis The electron will experience a force at 450 to the axis and hence execute a helical path The electron will continue to move with uniform velocity along the axis of the solenoid. Therefore F=0.

Q169. The motional EMF depends upon

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

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

Q170. The cyclotron frequency of an electron projected with velocity' perpendicular to a magnetic field B is given by

• A. f= mB/πC
• B. f= 2πeB/m
• C. f= eB/2πm✓
• D. f= 2πc/mB

Explanation: Correct option is C.Cyclotron frequency=f=qB/2πm​

Q171. An electron is projected horizontally from south to north in uniform horizontal magnetic field acting from west to east. The direction along which it will be deflected is:

• A. Northwards
• B. Southwards
• C. Vertically upwards✓
• D. Vertically downwards

Explanation: Apply the rule as shown in the following image . By this we get downward direction .But keep in mind we use the right hand rule for positive charge.In case of a negative charge we will take opposite conclusions so the direction of force (deflection) would be vertically upward in case of an electron.

Q172. An electron is moving along the axis of a solenoid carrying a current. Which of the following is a correct statement about the electromagnetic force acting on the electron?

• A. The force acts perpendicular to its motion
• B. The force acts anti-parallel to its motion
• C. The force acts in the direction of motion
• D. No force acts✓

Explanation: This is the following solution.

Q173. The magnetic lines of force are directed in a manner that they:

• A. Originate at south pole and terminate at north pole
• B. Pass through the magnet
• C. Originate at north pole and terminate at south pole✓
• D. Go away from both the poles

Explanation: Option A: This is incorrect. The magnetic lines of force originate at the north pole and terminate at the south pole. Option B: This is correct. The magnetic lines of force are continuous, so they must pass through the magnet. They do not pass through the magnet in a straight line, but rather they form loops that go around the magnet. Option C: The magnetic lines of force are directed in a manner that they originate at the north pole and terminate at the south pole. This is because the north pole of a magnet is a region where the magnetic field lines are pointing outwards, and the south pole of a magnet is a region where the magnetic field lines are pointing inwards. The magnetic lines of force are continuous, so they must pass through the magnet. They do not pass through the magnet in a straight line, but rather they form loops that go around the magnet. The magnetic lines of force do not go away from both the poles. If they did, then the magnetic field would be zero everywhere outside the magnet. However, the magnetic field is not zero outside the magnet. It is strongest near the poles of the magnet, and it decreases as you move away from the poles. Option D: This is incorrect. The magnetic lines of force do not go away from both the poles. If they did, then the magnetic field would be zero everywhere outside the magnet. However, the magnetic field is not zero outside the magnet. It is strongest near the poles of the magnet, and it decreases as you move away from the poles.

Q174. In the direction indicated by an electric field line:

• A. The electric field strength must increase
• B. The electric field strength must decrease
• C. The potential must decrease✓
• D. None of these

Explanation: c) The potential must decrease:This option suggests that in the direction indicated by an electric field line, the electric potential must decrease. This is generally true. Electric field lines point in the direction of decreasing electric potential. Therefore, when following the direction of an electric field line, you are moving from a region of higher potential to a region of lower potential.

Q175. Which of the following physical phenomena connot be described only by the wave theory of the electromagnetic radiation?

• A. Diffractions
• B. Interference
• C. Photoelectric effect✓
• D. Polarization

Explanation: The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material.

Q176. Which of the following is the same unit as the farad?

• A. Ωs
• B. Ωs–1
• C. Ω–1s✓
• D. Ω–1 s–1

Explanation: Farad is defined as charges held per unit of volt across the capacitor. Charges are current x time. So farad is the current x time over volt, or time over ohm.

Q177. Which experimental teachnique reduces the systematic error of the quantity being investigated?

• A. Adusting an ammeter to remove its zero error before measuring a current✓
• B. Measuring several internodal distance on a standing wave to find the mean Internodal distance.
• C. Measuring the diameter of a wire repeatedly and calculating the average.
• D. Timing a large number of oscillations to find a period.

Explanation: Systematic error means that measurements of the same thing will vary in predictable ways. Systematic errors in experimental observations usually come from the instruments which are used in measuring. So, zero error is recognized as the systematic error. Thus adjusting an instrument to remove its zero error before measuring something is the best experimental technique to reduce the systematic error of the quantity being investigated.

Q178. In a ripple tank, 40 waves pass through a certain point in 1 second. If the wavelength of the wave is 5 cm, then speed of the wave is:

• A. 0.5 ms-1
• B. 1 ms-1
• C. 1.5 ms-1
• D. 2 ms-1✓

Explanation: Use the formula “v=fλ” As it is known that 40 waves pass through the point in 1 second so frequency is 40.Wavelength is 5cm which can be converted to 0.05m as all options are having units in ms-1(metres per second). v=(0.05)(40)v=2ms-1

Q179. In which process the entire heat supplied to the gas is converted to the internal energy of the gas?

• A. Isochoric process✓
• B. Isobaric process
• C. Isothermal process
• D. Adiabatic process

Explanation: Formula for internal energy can be written as “ΔU=q+w”.For all the heat energy to be converted to internal energy work done(w) should be 0.Formula for work done is W=PΔV,so for it to be zero there should be no change in volume(volume should be constant),which is true for isochoric processes.

Q180. The internal energy of a system during an isothermal process:

• A. Decreases
• B. Increases
• C. Become zero
• D. Remain constant✓

Explanation: In an isothermal process the internal energy remains constant so the temperature remains constant. In an Isobaric process,the pressure remains constant. In adiabatic processes, the heat transfer is zero.In an isoenthalpic process, the enthalpy remains constant.

Q181. If the potential at a point which is 1m from a charge is 1 volt, then the potential at a point which is 2m from the same charge will be:

• A. 2 V
• B. 1 V
• C. 0.5 V✓
• D. 3 V

Explanation: Electric potential is given by V=kQ/r. As V is inversely proportional to r so by doubling the R(1m to 2m) the eclectic potential will become half(1 V-> 0.5 V).

Q182. The values of electric intensity will _ due to the presence of dielectric medium:

• A. Increase
• B. Increase exponentially✓
• C. Decrease
• D. Remain same

Explanation: The strength of the electric field is reduced due to the presence of dielectric. If the total charge on the plates is kept constant, then the potential difference is reduced across the capacitor plates.

Q183. The slope of distance - time graph will always be:

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

Explanation: The slope of the distance time graph will always be positive because distance can never decrease.

Q184. At what angle of projection of a projectile the range becomes half of its maximum value?

• A. 15✓
• B. 20
• C. 30
• D. 40

Explanation: R=Vi2(sin 2θ)/gAt given condition:Maximum range= Rmax= vi2θ/g. For the maximum range, sin2θ=1 which is possible if we put the angle as 45 degrees but to get half of the maximum range we should take θ such that sin2θ is equal to 0.5. It is known that sin 30=0.5 so if we put θ as 15 we will get sin2(15)=sin 30=0.5.

Q185. If we drop an object, it’s initial velocity is zero. How far will it fall in time ‘t’?

• A. 9.8 t^2
• B. 4.9 t^2✓
• C. 0.49 t^2
• D. 98 t^2

Explanation: Use the kinematics, straight line motion formula : s= u +½ at^2 s= 0 + ½ x 9.8x t^2 s= 4.9t^2

Q186. The newton-second is the unit of:

• A. Work
• B. Power
• C. Impulse✓
• D. velocity

Explanation: Impulse is the change in momentum. The formula for change in momentum is Force into the interaction period which is basically a particular time period. The unit of force is N and for time is s hence the unit for impulse is Ns. Another possible answer would be momentum but the important point to be noted here is the difference between momentum and the change in momentum.

Q187. A 1.75 m tall weight-lifter raises a weight of mass 50 kg to a height of 0.5 m above its head. How much work is being done by it? (g = 10 ms-2)

• A. 2125 J
• B. 2500 J
• C. 50 J
• D. 1125 J✓

Explanation: Work done = Force x parallel distance Force = mg : 50kg x 10 N/kg = 500 NDistance = 1.75m + 0.5m = 2.25 mW.D= 2.25m x 500 N = 1125 J

Q188. What is the speed of 2.0 kg metallic bob at the mean position of a simple pendulum, when released from its extreme position 0.5m high? (g = 10 ms-2)

• A. 3.16 ms-1✓
• B. 10 ms-1
• C. 100 ms-1
• D. 50 ms -1

Explanation: At the extreme displacement, the potential energy, (PE= mgh = 2x10x0.5= 10J) is equal to the total energy of the system.At the mean position, we have all the potential energy being converted to kinetic energy= KE =10 J = ½ mv210J = 1/2mv2mv2=20 -> 2v2 =20 -> v2= 10, hence v =3.16 ms-1

Q189. When the speed of your car is halved, by what factor does its kinetic energy decreases?

• A. ½
• B. ¼✓
• C. ⅛
• D. ⅙

Explanation: KE=½ mv2KE= ½ m(½v)2KE=⅛ mv2As it can be seen, the fraction reduces from 1/2 to 1/8 which means the Kinetic Energy decreased by 4 times or 1/4.

Q190. Which one of the following force is non-conservative:

• A. Frictional force✓
• B. Gravitational force
• C. Electric force
• D. Elastic spring force

Explanation: Frictional force is non conservative fields while elastic string force, electric, magnetic, and gravitational fields are constants. Non-conservational simply means energy is lost to the surroundings and does not get recycled.

Q191. The earth rotates on its axis once a day. Suppose, by some process the earth contracts so that it’s radius is only half as large as at present, then how long the earth will take to complete it’s rotation?

• A. 24 hours
• B. 18 hours
• C. 6 hours✓
• D. 12 hours

Explanation: Here we assume that the mass of earth remains the same, moment of the inertia of the earth rotating about its axis is : I=⅖ MR^2-------eq1 Angular velocity of the earth is: ω=2pi/T-------eq 2 When the radius is reduced to half, The new moment of inertia is I=2/5MR^2=2/5M(R/2)^2----eq3 New time period is T’ an angular velocity is: ω’=2pi/T’ Applying the law of conservation of angular momentum, we get: Iω=I’ω’ From eq 1,2,3, and 4 we get (2/5MR^2)*(2pi/T)=[2/5M(R/2)^2]*(2pi/T’) ->T’=T/4 But T=24 hrs T=24/6=6 hrs

Q192. Which surface will absorb more light?

• A. Yellow painted
• B. Blue painted
• C. White painted
• D. Black painted✓

Explanation: Dark, rough, and dull surfaces absorb radiation better than light, smooth, and shiny surfaces. Black surfaces have greater absorptivity,and hence,they absorb most of the light falling on it.

Q193. A set of Atoms in an excited state decays:

• A. In any general state with lower energy✓
• B. In any state when excited by electric field
• C. In any state when excited by magnetic field
• D. None of these options are correct

Explanation: As we know, atoms are stable in the ground state, when they move to another level by gaining energy, they get excited and are ready to lose energy to get back to the ground state. This shows, generally excited state atoms decay to any of the states with lower energy. Hence,the correct option is A in any general state with lower energy which is more stable than the excited state.

Q194. What is the number of spectral series in the hydrogen spectrum?

• A. Four
• B. Three
• C. Five✓
• D. One

Explanation: The five spectral series are Lyman, Balmer, Paschen, Brackett and Pfund. In the Lyman series, the electron falls back to n = 1. The spectral lines obtained are in the UV region of the electromagnetic spectrum. In the Balmer series, the electron falls back to n = 2 and the spectral lines obtained are in the visible region of the EM spectrum. Paschen, Brackett, and Pfund spectral lines are obtained in the Infrared region of the EM spectrum.

Q195. 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.

Q196. 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.

Q197. 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.

Q198. 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

Q199. 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.

Q200. 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.