Kpk Mdcat Mock Paper 2 — Solved Past Paper with Answers

Q1. Choose the word most similar in meaning to the capitalized one: AMAZEMENT:

• A. surprise✓
• B. appreciation
• C. criticism
• D. praise
• E. objection

Explanation: Amazement implies something that has an element of shock or astonishment. The word “surprise” best fits here.

Q2. Antonym of Atheist will be:

• A. Hypnotic
• B. Bane
• C. Believer✓
• D. Theorist

Explanation: Atheist means someone who denies or disbelieves in the existence of god.

Q3. Select the nearest correct meaning of the given word: FROWSY

• A. Disheveled✓
• B. Arranged
• C. Drowsy
• D. Bluish

Explanation: Dishelved means unkempt, untidy, or dirty. It is the closest in meaning to frowsy because it describes a person or thing that is not well-groomed or that is in a state of disarray.

Q4. Complete the sentences by choosing the most appropriate option, from the given lettered choices (A to D) below each:We must _ back by six o’clock.

• A. Be✓
• B. Can
• C. Has
• D. Have

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. Be is the only option that fits in well

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. When a tree fell on our house, the insurance company adjuster said he would_the damage and pay us accordingly.

• A. Transmute
• B. Undulate
• C. Wan
• D. Evaluate✓

Explanation: To evaluate is to assess the worth/ extent. (of the damage).

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 sunlight shining through the branches made a _ pattern on the tiles.

• A. Angina
• B. Basilica
• C. Filigree✓
• D. Corollary

Explanation: Filigree is a design of fine work.

Q7. In the following question, four alternative sentences are given. Choose the CORRECT option.

• A. After breaking the glass, Ruby said "Please don't tell on me".
• B. After breaking the glass Ruby said: "Please don't tell on me."
• C. After breaking the glass, Ruby said: "Please don't tell on me."✓
• D. After breaking the glass Ruby said: please don't tell on me.

Explanation: The sentence 'after breaking the glass' is another idea in the sentence hence a comma should be added between these two sentences. The rule of punctuation in quotation marks is that the full stop or comma should come within the quotation marks. 'Don't' is a contraction, which stands for 'do not'.

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. My parents _ near Lahore.

• A. Living
• B. Are living
• C. Lives
• D. Live✓

Explanation: Option A : "Living near" is incorrect as it does not agree with the subject-verb agreement.Option B : "Are living" is also incorrect as it uses the present continuous tense, which is not suitable for describing a present state.Option C : "Lives" is incorrect as it is in the third-person singular form, which does not agree with the subject "my parents," which is in the plural form Parents is a plural noun so the verb used should be singular.

Q10. Our neighbours have _ cat and _ dog.

• A. A...an
• B. A...a✓
• C. A....the
• D. An....an

Explanation: Correct answer is B

Q11. I lived on _ Main Street when I first came to town.

• A. A
• B. An
• C. The
• D. No article is required✓

Explanation: In general, no article is used with proper nouns, mass nouns where the reference is indefinite, or plural count nouns where the reference is indefinite.

Q12. Demonstrate correct use of the subject-verb agreement. I am _ tea now.

• A. taking✓
• B. takes
• C. took
• D. take

Explanation: Since Now is used , it indicates that the work is being done now. For this we use present continuous tense.

Q13. My father _ us popcorn and orange juice.

• A. Buy
• B. Will buy
• C. Bought✓
• D. Have bought

Explanation: The verb "bought" is in the past tense and indicates that the action of buying has already been completed in the past.

Q14. It’s raining cats and dogs. So there are _ cars on the road today.

• A. few✓
• B. a few
• C. a big number of
• D. a great deal of

Explanation: Few means "not many (people or things)."A few means "some (people or things)." Few cars” would imply almost no cars. 'A few cars' suggests there are not very many cars. So the first is a comparison, while the second is a quantity. Since we are comparing the number of cars on the road when it is raining with when it is not, we would use “few cars” hence the correct answer is A whereas options C and D are not logically correct because on rainy days we don’t see many cars.

Q15. Saba was sick on the bus. [The underlined prepositional phrase functions as a _ in this sentence:]

• A. Adjunct
• B. Disjunct
• C. Conjunct
• D. Adverbial✓

Explanation: Adverbials give more information about verbs and even if dropped, it won’t have a significant impact on the sentence hence D is the right answer.

Q16. ‘To the letter’ means:

• A. Cursory
• B. Enveloping a letter
• C. Precisely✓
• D. Reporting a problem

Explanation: it means with adherence to every detail.

Q17. A person who leaves his country and settles in another country is called:

• A. Emigrant✓
• B. Immigrant
• C. Migrant
• D. Aborigine

Explanation: immigrant is used in reference to the country moved to, and emigrant is used in reference to the country moved from

Q18. The cell wall of most of the bacteria have a unique macromolecule called_.

• A. Cellulose
• B. Chitin
• C. Fibres
• D. Fats
• E. Peptidoglycan✓

Explanation: A cell wall is a layer located outside the cell membrane found in plants, fungi, bacteria. Plant cell is made up of cellulose, fungi cell of chitin and bacteria cell is made up of peptidoglycan.

Q19. Which is distributed more widely in a cell?

• A. DNA
• B. RNA✓
• C. Chloroplasts
• D. Phagosomes

Explanation: (b) : RNA occurs in the nucleus as well as in the cytoplasm of the eukaryotic cells and in a prokaryotic cell, it is found in the cytoplasm. DNA is found in the nucleus, mitochondria, and chloroplast. Chloroplast and phagosomes are found only in the cytoplasm.

Q20. What is the most abundant carbohydrate in nature?

• A. Cellulose✓
• B. Starch
• C. Fructose
• D. Glycogen

Explanation: A type of carbohydrate, cellulose contains chains of glucose rings providing strength and rigidity. Cellulose forms the cell walls of plants and is the primary constituent of wood, making this organic compound the most abundant one on the surface of the Earth.

Q21. How many water molecules will be released upon the formation of a trisaccharide?

• A. 1
• B. 2✓
• C. 3
• D. 4

Explanation: A tri-saccharide is a molecule containing three monosaccharides. There is single glycosidic bond between two adjacent monosaccharides and the third monosaccharide will bind to the already bound disaccharide by forming another glycosidic bond.Thus there will be two glycosidic bonds and one water molecule will be released from each glycosidic bond.

Q22. A powerful digesting enzyme that is capable of destroying a cell's internal structure is called _

• A. Lipase
• B. DNase
• C. Phospholipase
• D. B and c✓

Explanation: A. Lipid-digesting enzyme B. DNA-digesting enzyme C. Phospholipid-digesting enzyme D. Protein-digesting enzyme Since we are talking about cell destruction, the most common mean of destroying a cell is by releasing Lysosomes. Lysomsomes are known to contain both, Lipase and Phospholipase, however since we are referring to the cell, it's internal structure can be destroyed when the phospolipid-containing cell membrane is broken down.

Q23. Which of these enzymes work best at a pH of 2.00?

• A. Sucrase
• B. Salivary amylase
• C. Pepsin✓
• D. Enterokinase

Explanation: Optimum pH of pepsin is 2.

Q24. Which one of the following cell organelles is enclosed by a single membrane?

• A. Lysosomes✓
• B. Nuclei
• C. Mitochondria
• D. Chloroplasts

Explanation: Lysosomes are small vesicles bounded by a single membrane and contain hydrolytic enzymes. Nucleus, mitochondria and chloroplasts are double membrane bound cells organelles.

Q25. The nuclear envelope is a derivative of

• A. microtubules
• B. rough endoplasmic reticulum✓
• C. smooth endoplasmic reticulum
• D. membrane of Golgi complex.

Explanation: Recent developments have shown that the nuclear membrane is derived from rough endoplasmic reticulum. During cell division, the nuclear membrane is disintegrated. The nuclear envelope transmembrane proteins are absorbed in the RER. Once the division is completed, RER reassembles the nuclear envelope.

Q26. Tobacco mosaic virus (TMV) genes are

• A. single stranded RNA✓
• B. double stranded DNA
• C. Proteinaceous
• D. double stranded RNA.

Explanation: Tobacco Mosaic Virus is a ribovirus and contains single stranded RNA. It was proved by the experiments of Frankel Conart that RNA is the genetic material in this virus. It does not contain any DNA and is composed of 6 % RNA surrounded by a hollow cylinder of portion subunits. Double stranded RNA is found in Reovirus and Tumor virus. Retroviruses have two copies of single stranded RNA.

Q27. Which of the following statements about enzymes is false?

• A. The Keq of a reaction remains unchanged in the presence of an enzyme.
• B. Enzymes speed up the rate of reaction in DNA synthesis.
• C. Harsh, acidic conditions can completely denature an enzyme.
• D. An enzyme is completely converted to product during metabolism.✓

Explanation: Enzymes are not consumed or completely converted to products during metabolism. Enzymes are catalysts that facilitate and accelerate biochemical reactions without being consumed or altered in the process. They remain unchanged after the reaction and are available to catalyze additional rounds of the same reaction.

Q28. The ability to distinguish between two separate points/objects is:

• A. Magnification
• B. Fractionation
• C. Centrifugation
• D. Resolution✓

Explanation: Scientists think of resolution as the ability to tell that two objects that are very close together are distinct objects rather than just one.Fractionation is a separation process in which a certain quantity of a mixture (gas, solid, liquid, enzymes, suspension, or isotope) is divided during a phase transition, into a number of smaller quantities (fractions) in which the composition varies according to a gradient.Centrifugation is a technique used for the separation of particles from a solution according to their size, shape, density, viscosity of the medium and rotor speed. The particles are suspended in a liquid medium and placed in a centrifuge tube. The tube is then placed in a rotor and spun at a defined speed.Magnification is the process of enlarging the apparent size, not physical size, of something

Q29. A man has to face interview, but during his first five minutes before the interview he experiences sweating, increased heart rate and respiration. Which hormone is responsible for his restlessness

• A. Adrenocorticotropic hormone
• B. Insulin and glucagon
• C. Epinephrine and norepinephrine✓
• D. Aldosterone

Explanation: Epinephrine and norepinephrine are the hormones behind your “fight-or-flight” response which involves increased heart rate and heavy breathing. thus C is the correct option.

Q30. Hypothalamus connected to pituitary gland via:

• A. Nerves
• B. Infundibulum✓
• C. Blood
• D. No connection

Explanation: Hypothalamus and the Pituitary gland is connected by the pituitary stalk, or more technically, the infundibulum

Q31. The enzyme which is found in saliva, accelerates the conversion of starch into sugar is

• A. Pepsin
• B. Thrombin
• C. Ptyalin✓
• D. Fumarase

Explanation: Amylase is the enzyme in saliva that digests starch and ptyalin is an amylase

Q32. Find mismatch

• A. Thyroid gland-T3 and T4
• B. Parathyroid gland-Calcitonin✓
• C. Pancreas-Insulin
• D. Gonads-Testes and ovaries

Explanation: The gonads are the testes in the male and the ovaries in the female.T3 and T4 are the two major hormones made by the thyroid, The most important hormone that the pancreas produces is insulin. The parathyroid gland lies just behind the thyroid gland in the neck and produces PTH which appears to work against calcitonin. Thus, option B is the correct answer

Q33. To the end of the first trimesters the embryo can now technically describe as a

• A. Zygote
• B. Infant
• C. Toddler
• D. Fetus✓

Explanation: At the beginning of the 11th week of pregnancy, or the ninth week after conception, The baby's head still makes up about half of its length. However, The baby's body is about to catch up. The baby is now officially described as a fetus.

Q34. Recombinants contains DNA from

• A. 2 different sources✓
• B. Single source
• C. 2 same sources
• D. 3 same sources

Explanation: Recombinant DNA technology is the joining together of DNA molecules from two different species. The recombinant DNA molecule is inserted into a host organism to produce new genetic combinations that are of value to science, medicine, agriculture, and industry.

Q35. The animals which eat both plant and animal foods are called

• A. Filter feeders
• B. Omnivores✓
• C. Fluid feeders
• D. Macrophagus feeders

Explanation: A. Many aquatic animals filter the water and digest the particles that they extract from it C. When food in ingested in liquid forms D. Animals which take food in the form of large pieces are microphagous feeders

Q36. Expiratory centre in medulla is:

• A. Dorsal✓
• B. Ventral
• C. Lower part
• D. All of the above

Explanation: In summary, the correct answer is "a) Dorsal." The expiratory center in the medulla is located in the dorsal (back) part of the brainstem. The other options do not accurately represent the location of the expiratory center.

Q37. When the sperm count is high, inhibin hormone release increases which:

• A. Inhibits anterior pituitary release follicle stimulating g hormone✓
• B. Increase anterior pituitary release of follicle stimulating hormone
• C. Inhibit release of luteinizing hormone
• D. Increaserelease of luteinizing hormoneave

Explanation: When the sperm count exceeds set limits,The hormone inhibits GnRH and FSH, decreasing the activity of the Sertoli cells. It inhibits the synthesis and release of the follicle-stimulating hormone in the pituitary gland and reduces the hypothalamic LH - releasing hormone content.

Q38. In the intestine, amino acids are absorbed by?

• A. None of these
• B. Capillaries✓
• C. Lacteals
• D. Both of these

Explanation: Amino acids, being water-soluble like most of the other nutrients, are absorbed by capillaries of the villus of the small intestine. The fats and fat-soluble vitamins, however, are absorbed by the lacteals.

Q39. Lock and Key Model for enzyme action propose by Emil Fischer suggests that:

• A. Enzymes are unbiased for the substrate
• B. Enzymes can modify their active sites
• C. Enzymes are restricted to one reaction type✓
• D. An enzyme can catalyze variety of reactions

Explanation: The lock and key mechanism is a metaphor to explain the specificity of the enzyme's active site and the substrate. Similar to how only a certain key fits a lock, only certain substrates can fit an enzyme's active site. When the correct substrate binds to the enzyme's active site, an Enzyme substrate complex is formed. This simply means that only one type of substrate can be acted upon by an enzyme. The statement C implies that since only one type of substrate can fit into the active site of an enzyme, the type of reaction either being catabolic or anabolic in nature is also dependent on the active site of the enzyme and the type of substrate. To further explain, consider an example of an enzyme A acting on a substrate A in a catabolic reaction. It would only be able to catalyze the catabolic reaction and not any other type of reaction such as anabolic reaction on that particular substrate. A and D, on the other hand, are the exact opposite of the above statements as enzymes are specific for the substrate.

Q40. Most enzymes have an optimum temperature of around:

• A. 30°C
• B. 40°C✓
• C. 50°C
• D. 20°C

Explanation: Most enzymes have an optimum temperature at which they function most efficiently. For many enzymes in the human body, this optimum temperature is around 37 degrees Celsius (98.6 degrees Fahrenheit), which is the normal body temperature. However, the specific optimum temperature can vary for different enzymes. Hence here we will select 40 degrees Celsius.

Q41. Carotenoids perform protective function in which of the following organism?

• A. Animals
• B. Plants
• C. Both✓
• D. None of these

Explanation: Carotenoids perform a protective function in plants. They act as pigments and antioxidants, helping to protect plant cells from damage caused by excessive light and reactive oxygen species. Moreover, carotenoid pigments, present in many eyes and photoreceptors, seem especially suited to protect against the deleterious effects of light because they absorb the dangerous short wavelength part of the light spectrum. Hence correct option is option C.

Q42. Cholesterol is:

• A. Animal sterol
• B. C27H46O
• C. 5 methyl groups
• D. All of these✓

Explanation: Cholestrol is an animal sterol which the structure shown below indicating the presence of 5 methyl groups and the molecular formula C27H46O.

Q43. Reverse transcriptase is a useful enzyme to have when

• A. RNA virus converts its RNA to DNA✓
• B. there are no host cells present
• C. nutrients are scarce
• D. spikes are forming in the new virus

Explanation: Reverse transcriptase is an enzyme that allows the conversion of RNA into DNA. It is commonly found in retroviruses, such as HIV, where it plays a crucial role in the replication of the viral genome. By converting the viral RNA into DNA, the virus is able to integrate its genetic material into the host cell's DNA and hijack the host's cellular machinery to produce new virus particles. Reverse transcriptase is also used in molecular biology research, such as in the polymerase chain reaction (PCR) technique.

Q44. Two species can avoid competition and can make better use of the environment's resources by occupying different:

• A. Adaptation
• B. Polymorphism
• C. Niches✓
• D. Specialization

Explanation: A niche is an exact position or location, so if two species occupy different niches, they will be having separate reservoirs of environmental resources. Hence, there will be no competition to survive and avail the resources. However, if they occupy different polymorphisms, adaptations, or specializations (options A, C, and D) they will still be sharing the resources which will create competition.

Q45. How many ml of oxygen are present in a litre of water?

• A. 10✓
• B. 20
• C. 40
• D. 200

Explanation: Water has a low oxygen content compared to equal volume of air. A litre of water contains less than "10 ml" of oxygen.

Q46. Which of the following combination is an example of self-replicating organelles?

• A. Mitochondria and Ribosomes
• B. Mitochondria and Chloroplast✓
• C. Mitochondria and Vacuole
• D. Mitochondria and lysosomes

Explanation: Both mitochondria and chloroplasts are self replicating as they contain their own DNA and enzymes.

Q47. The nephridia in earthworm are analogous to

• A. nematoblasts of Hydra
• B. flame cells of Planaria✓
• C. gills of prawn
• D. trachea of insects.

Explanation: Analogous organs are organs of very disparate organisms that are superficially similar but have evolved from vastly different origins. They have the same function but different structures. The nephridia in earthworm are analogous to flame cells of Planaria since both of them have excretory functions. Nematoblasts of Hydra are organs of locomotion, food capture and anchorage. Gills and trachea are organs of respiration in prawn and insects respectively.

Q48. Which of the following is an example of class by bivalvia?

• A. Anodonta✓
• B. Lolgio
• C. Limax
• D. Sepia

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

Q49. A graph plotting absorption of light of different wave lenghts by a pigment is called as:

• A. Absorption spectrum✓
• B. Spectrophotometer
• C. Carotenoids
• D. Xanthophylls

Explanation: B. It is an instrument which is used to measure relative abilities of different pigments to absorb different wavelenght of lightC. These are accessory photosynthetic red ,orange and yellow pigments present in chloroplast.D. These are yellow colour accessory pigments present in chloroplast.

Q50. The breakdown of glucose in cell yields pyruvate in the:

• A. Presence of oxygen
• B. Absence of oxygen
• C. Presence or absence of oxygen✓
• D. High Conc. of oxygen

Explanation: Based on the explanations provided, the correct answer to the question is option C) Presence or absence of oxygen.

Q51. Which cartilage is present at the end of long bones?

• A. Calcified cartilage
• B. Hyaline cartilage✓
• C. Elastic cartilage
• D. Fibrous cartilage

Explanation: Cartilage is an important component of skeleton. It consists of a firm matrix containing collagen and elastin fibres and cells in fluidfilled lacunae. Cartilage has many types. Elastic cartilage occurs in the pinna and external auditory canal of the ear, epiglottis, Eustachian tubes and tip of the nose to make these organs flexible. Fibrous cartilage is very strong yet has a degree of flexibility. It is found in the intervertebral discs where it acts as a cushion and in pubic symphysis where it allows parturition without damage to the girdle. Hyaline cartilage occurs in sternal ribs where it allows expansion of chest during inspiration. It also forms the tracheal and bronchial rings and supports larynx and nasal septum and also at the end of long bones.

Q52. The repeated protein pattern of myofibrils is called:

• A. Sarcomere✓
• B. Sarcolemma
• C. Zyomere
• D. Cross bridges

Explanation: A sarcomere is the basic functional unit of a muscle. It is the repeating unit within myofibrils, which are thread-like structures found in muscle cells. Sarcomeres are responsible for muscle contraction. They consist of overlapping filaments of actin and myosin, which slide past each other during muscle contraction, leading to the shortening of the sarcomere and the overall contraction of the muscle.

Q53. Smooth reficulum are similar in structure to:

• A. RER
• B. Golgi bodies
• C. Microfilaments
• D. Sarcoplasmic reticulum✓

Explanation: The nerve impulse is carried through the T-tubule to the adjacent sarcoplasmic reticulum (SR). thecalcium gates of the ST open releasing calcium into the cytosol, thus binding calcium ion to troponin molecules of the thin filament.

Q54. About 55% of the volume of human blood is:

• A. Plasma✓
• B. Blood cells
• C. Blood Protein
• D. A and B

Explanation: About 55% of the volume of human blood is plasma. Plasma is the liquid component of blood that makes up the majority of its volume. It contains water, electrolytes, hormones, waste products, and various proteins.

Q55. About which day in a normal human menstrual cycle does rapid secretion of LH (popularly called LH surge) normally occurs?

• A. 14th day✓
• B. 20th day
• C. 5th day
• D. 11th day

Explanation: Both LH and FSH attain a peak level in the middle of menstrual cycle (about 14 th day). Rapid secretion of LH leading to its maximum level during the mid­cycle called, LH surge, induces rupture of Graafian follicle and thereby the release of ovum (ovulation).

Q56. Freshly released human egg has:

• A. One Y chromosome
• B. One X ­chromosome✓
• C. Two X­ chromosome
• D. One X ­chromosome and one Y­ chromosome

Explanation: A freshly released human egg, also known as an oocyte, contains half of the genetic material required for the formation of a new individual. To be specific, it contains 23 chromosomes. However, all of these chromosomes are from the X chromosome group. There are no Y chromosomes in a freshly released human egg. This is because the egg always carries an X chromosome, while the sex of the resulting individual (male or female) is determined by the sperm cell that fertilizes the egg. Now, let's explain each of the options: a. One Y chromosome: This option is incorrect. There is no Y chromosome present in a freshly released human egg. b. One X chromosome: This option is correct. A freshly released human egg does indeed have one X chromosome. c. Two X chromosomes: This option is incorrect. A freshly released human egg only contains one X chromosome. d. One X chromosome and one Y chromosome: This option is incorrect. As mentioned earlier, the egg only contains one X chromosome, and the Y chromosome is not present in the egg. Correct answer: b. One X chromosome Summary: A freshly released human egg has one X chromosome. The presence of the Y chromosome or the determination of the individual's sex (male or female) is determined by the sperm cell that fertilizes the egg. The egg always contributes an X chromosome, and the sperm can contribute either an X or a Y chromosome, resulting in the genetic sex of the offspring.

Q57. Human embryo remains enclosed in:

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

Explanation: The human embryo remains enclosed in the amnion, which is a protective sac filled with amniotic fluid. The amnion is one of the fetal membranes that develop during pregnancy.The amnion is the innermost layer that directly surrounds and protects the developing embryo.

Q58. Thalassemia and sickle cell anemia are caused due to a problem in globin molecule synthesis. Select the correct statement:

• A. Both are due to a quantitative defect in globin chain synthesis
• B. Thalassemia is due to less synthesis of globin molecules✓
• C. Sickle cell anaemia is due to a quantitative problem of globin molecules
• D. Both are due to a qualitative defect in globin chain synthesis

Explanation: Sickle cell anemia is caused due to point mutation in which at the 6th position of the beta-globin chain, glutamic acid is replaced by valine. Thus, it is a qualitative defect in the functioning of globin molecules. Sickle cell anemia is caused due to point mutation in which at the 6th position of the beta-globin chain, glutamic acid is replaced by valine. Thus, it is a qualitative defect in the functioning of globin molecules. Thalassemia is caused due to either mutation or deletion which ultimately results in a reduced rate of synthesis of one of the globin chains that make up hemoglobin. Hence, it is a quantitative defect in the functioning of globin molecules.ing of globin molecules.

Q59. A normal-­visioned man whose father was colour­-blind marries a woman whose father was also colour-­blind. They have their first child as a daughter. What are the chances that this child would be colour­-blind?

• A. 100%
• B. Zero percent✓
• C. 25%
• D. 50%

Explanation: Color blindness is an X-linked disease. So, a woman whose father was color blind will be a carrier for the disease. Color blindness is an X-linked disease. So, a woman whose father was color blind will be a carrier for the disease. After looking at the crosses, the daughter born to them can be either normal or a carrier for the disease, but the possibility of color blindness is zero percent. possibility of color blindness is zero percent. Color blindness is an X-linked disease. So, a woman whose father was color blind will be a carrier of the disease. After looking at the crosses, the daughter born to them can be either normal or a carrier for the disease, but the possibility of color blindness is zero percent. So, the correct option is 'Zero percent'.

Q60. A test cross is carried out to:

• A. Determine the genotype of a plant at F2✓
• B. Predict whether two traits are linked
• C. Assess the number of alleles of a gene
• D. Determine whether two species or varieties will breed successfully or not

Explanation: A test cross is performed to determine the genotype of the F2 plant. In a typical test cross, an organism showing dominant phenotype and whose genotype is to be determined is crossed with one that is homozygous recessive for the allele being investigated, instead of self­crossing. The progenies of such a cross can easily be analyzed to predict the genotype of the test organism. Given ahead is an illustration of a test cross:

Q61. Which one of the following conditions correctly describes the manner of determining the sex?

• A. Homozygous sex chromosomes (ZZ) determine female sex in birds.
• B. XO type of sex chromosomes determine male sex in grasshopper.✓
• C. XO condition in humans as found in Turner’s syndrome, determines female sex.
• D. Homozygous sex chromosomes (XX) produce male in Drosophila.

Explanation: XO type of sex chromosomes determines male sex in grasshoppers. This type of sex­-determination comes under XX­-XO type. Its common examples are cockroaches, grasshoppers, and bugs. The female has two homomorphic sex chromosomes XX and is homogametic. It produces similar eggs, each with X­-chromosome. The male has one chromosome only and is heterogametic. It produces 2 types of sperms and gymnosperms with X and angiosperms without X. Fertilization of an egg by X­-bearing sperm yields female offspring and by no X sperm yields male offspring.

Q62. Lungs are made up of air­filled sacs, the alveoli. They do not collapse even after forceful expiration because of

• A. inspiratory reserve volume
• B. tidal volume
• C. expiratory reserve volume
• D. residual volume✓

Explanation: (d) : Residual volume is the volume of air which remains in the lungs after the most forceful expiration. This residual air enables the lungs to continue the exchange of gases even after maximum exhalation. Due to this, lungs do not collapse even after forceful expiration.

Q63. Which wave lengths are mainly absorbed by chlorophyll?

• A. Violet blue and red✓
• B. Green and blue
• C. Violet and orange
• D. Red and indigo

Explanation: Chlorophyll primarily absorbs light in the blue and red regions of the electromagnetic spectrum. The violet-blue and red wavelengths are most efficiently absorbed by chlorophyll, while green wavelengths are less effectively absorbed and are, instead, reflected, which is why chlorophyll-containing plants appear green to our eyes.

Q64. Sulphur bacteria belongs to sun group of bacteria called

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

Explanation: Sulfur bacteria belongs to gamma proteo bacteria which take part in nitrogen and sulfur cycling processes

Q65. The possible reason(s) for cyanosis, one of congenital heart disease is

• A. Formation of carboxy-hemoglobin✓
• B. The high concentration of oxyhemoglobin
• C. Low level of CO
• D. Low level of hemoglobin

Explanation: Cyanosis indicates there may be decreased oxygen attached to red blood cells in the bloodstream such as due to the formation of carboxy-hemoglobin. Carbon Monoxide has a higher affinity with hemoglobin and it doesn’t allow oxygen to bind to Hb molecules

Q66. The deficiency of which micronutrient causes goiter formation?

• A. Iron
• B. Zinc
• C. lodine✓
• D. Sodium

Explanation: Goiter is a condition in which the thyroid in neck enlarges, this happens mainly due to the lack of iodine in diet.

Q67. In humans the disease symptoms develop during the:

• A. Log phase✓
• B. Lag phase
• C. Growth phase
• D. Decline phase

Explanation: Bacterial cells divide at exponential rate during log phase, hence disease symptoms become prominent during this phase.

Q68. XO in drosophila result in sterile:

• A. Female
• B. Male✓
• C. Both (A) & (B)
• D. No effect

Explanation: XO in drosophila results in a sterile male. As XO means the absence of the second chromosome. The male has only one X chromosome and one Y chromosome, while the female has two X chromosomes. So, when offspring of drosophila carry one X chromosome from a male and one X chromosome from a female it results in a normal female but when offspring of drosophila carry one X chromosome from a female and no chromosome from a male then it results in a sterile male.

Q69. How many sperms are produced from fifty secondary spermatocyte?

• A. 200
• B. 100✓
• C. 50
• D. 150

Explanation: The secondary spermatocyte continues into meiosis II and each spermatocyte forms two sperm. So, 2x50=100.

Q70. The first successful surgery of heart was performed by Dr. Ludwig by repairing a wound on which part:

• A. Right auricle
• B. Right ventricle✓
• C. Left auricle
• D. Left ventricle

Explanation: The first successful surgery of the heart was performed by Dr. Ludwig by repairing a wound on the Right ventricle.

Q71. Which of the following is absent in C4 Plants:

• A. Calvin Cycle
• B. Bundle Sheath cells
• C. Pepco
• D. CO2 Fixation in Mesophyll✓

Explanation: CO2 fixation does occur in the mesophyll cells of C4 plants, but it follows a different pathway compared to C3 plants. C4 plants have evolved a specialized mechanism to minimize photorespiration and increase their efficiency in photosynthesis, especially under conditions of high temperature and intense sunlight. In C4 plants, the initial fixation of CO2 takes place in mesophyll cells, and the primary fixation product is a four-carbon compound called oxaloacetate (OAA). This process is catalyzed by an enzyme called phosphoenolpyruvate carboxylase (PEP carboxylase). OAA is then converted into malate or aspartate, which are transported to bundle sheath cells surrounding the vascular bundles.

Q72. Goblets cells are:

• A. Unicellular exocrine gland✓
• B. Unicellular endocrine glands
• C. Multicellular exocrine gland
• D. Multicellular endocrine glands

Explanation: The most common unicellular exocrine glands are the goblet cells (mucus secreting cells) found in the epithelium of the trachea and the digestive tube.

Q73. The first hormone to be discovered was:

• A. Secretin✓
• B. Testosterone
• C. Insulin
• D. Thyroxin

Explanation: Wm. M. Bayliss and Ernest H. Starling discovered secretin, the first hormone, in 1902. They discovered this hormone when they were studying pancreatic secretion. Secretin hormone stimulates the pancreas to secrete digestive fluid.

Q74. A condition called Goose pimples, are caused by:

• A. Overcooled body✓
• B. Bacteria
• C. Environmental changes
• D. Pollution

Explanation: The hairs in mammals act as insulating organs and reduce heat loss. Thus the heat is retained in the body to a certain extent. To increase the effect of insulation, the hairs are erected. This occurs involuntarily when the body is over-cooled. In humans, it produces Goose pimples.

Q75. In E.C.G QRS complex represent:

• A. Atrial systole
• B. Arial diastole
• C. Ventricle systole✓
• D. Ventricle diastole

Explanation: The second part of ECG is the QRS complex which features a small drop in voltage (Q) a large voltage peak ( R ) and another small drop in voltage (S). The QRS complex corresponds to the depolarization of the ventricle during ventricle systole.

Q76. The common name of rubella is:

• A. Whooping cough
• B. German measles✓
• C. African sleeping Sickness
• D. Tay Sach’s Disease

Explanation: It is also called German measles, but it is caused by a different virus than measles.

Q77. The organism developed with two heads and one trunk is called:

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

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

Q78. XX-XY type of sex determination pattern is present in which of the following organisms?

• A. Humans
• B. Butterflies
• C. Grasshopper
• D. Drosophila
• E. Both A and D✓

Explanation: The XY sex-determination system is the sex-determination system found in humans, most other mammals, some insects (Drosophila), and some plants (Ginkgo).

Q79. Otitis media is an inflammation of which part of the

• A. Brain
• B. Middle ear✓
• C. Lungs
• D. Urinary tract

Explanation: Otitis media is an inflammation of the middle ear. The eustachian tubes equalise the pressure between the middle ear cavity and the outside mucus to drain out of the middle ear cavity. Inflammation of the middle ear causes the tubes to close causing the fluid to become trapped. Bacteria travel from the back of the nose through the fluid in the eustachian tube directly into the middle ear cavity and multiply in the fluid.

Q80. How many nucleotides are in 12 mRNA codons?

• A. 12
• B. 24
• C. 36✓
• D. 48

Explanation: 12 mRna codons there are 36 nucleotides. As 3 nucleotide cob]combine to form one codon so 3 multiply by 12 gives 36.

Q81. Sarcolemma is the membrane around?

• A. Bone
• B. Joints
• C. Muscle fiber✓
• D. Heart

Explanation: The sarcolemma is the plasma membrane of the muscle cell and is surrounded by basement membrane and endomysial connective tissue. The sarcolemma is an excitable membrane and shares many properties with the neuronal cell membrane.

Q82. Which one is not an opportunistic disease related to HIV infection:

• A. Destruction of body immune system✓
• B. Recurrent pneumonia
• C. Pulmonary tuberculosis
• D. Toxoplasmosis

Explanation: People with aids have badly damaged immune systems. They get an increasing number of severe illnesses called opportunistic infections which include tuberculosis toxoplasmosis and pneumonia.

Q83. What event is thought to have contributed to the evolution of eukaryotes ?

• A. Global warming
• B. Glaciations
• C. Volcanic activity
• D. Oxygenation of the atmosphere✓

Explanation: The production and release of oxygen, by cyanobacteria and algae, lead to evolution of eukaryotic cells as they contain a membrane-bound nucleus and are the building blocks of complex multicellular organisms

Q84. Rhizobium belongs to:

• A. Beta-protobacteria
• B. Gama-protobacteria
• C. Alpha-protobacteria✓
• D. Delta-protobacteria

Explanation: Rhizobium belongs to alpha proto-bacteria, this is a fact and has to be learnt

Q85. ABO Blood groups are an example of:

• A. Multiple alleles and incomplete dominance
• B. Co dominance and incomplete dominance
• C. Incomplete dominance only
• D. Multiple alleles and co dominance✓

Explanation: The human ABO blood group system exhibits codominance. It consists of three alleles A, B, and O. Both A and B show codominance

Q86. What will be the geometrical shape of a molecule that contains two lone pairs and two bond pairs of electron in valence shell of central atom?

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

Explanation: If there are two bond pairs and two lone pairs of electrons the molecular geometry is angular or bent (e.g. H2O).

Q87. Which one of the following gas has the highest rate of diffusion at the same temperature and pressure?

• A. HCL
• B. CO2
• C. C2H2✓
• D. C2H6

Explanation: Graham Law states Rate of Diffusion ∝ 1/√(MolecularMass) Option A: HCl has molecular mass 36g Option B: CO2 has molecular mass 44g Option C: C2H2 has molecular mass 26g Option D: C2H6 has molecular mass 30g As C2H2 has lowest molecular mass, it has highest rate of diffusion.

Q88. At higher altitude, the boiling point of water is less than 100°C. This is because of:

• A. Higher atmospheric pressure
• B. Weak hydrogen bonding
• C. No change in atmospheric pressure
• D. Lower atmospheric pressure✓

Explanation: Boiling point of water is lower at higher altitudes due to the decreased atmospheric pressure

Q89. How many elements are there in the third period of the periodic table?

• A. 18
• B. 8✓
• C. 32
• D. 10

Explanation: Second and third period are called short periods and contain eight elements.The third period contains eight elements: sodium, magnesium, aluminium, silicon, phosphorus, sulphur, chlorine, and argon

Q90. When ammonium cyanide (NH4CN) salt is dissolved in water the solution will be

• A. Neutral
• B. Acidic
• C. Basic✓
• D. Both acidic and basic

Explanation: Smaller the pKa , the stronger the acid. Very strong acids have pKa less than 1, moderately strong acids have pKa in between 1 to 5 and weak acids have pKa above 5.Ka is directly proportional to the H+ concentration and Kb is directly proportional to the OH- concentration.

Q91. In the complex, potassium hexacyanoferrate (III). K3 Fe(CN6)1 the coordination of the Fe is

• A. 9
• B. 3
• C. 6✓
• D. 5

Explanation: Coordination number, also known as ligancy, is the number of atoms, ions, or molecules that a central atom or ion carries in a complex or coordination compound or in a crystal as its closest neighbours co-ordination number of Fe in K3[Fe(CN)6] 6 . Since Fe atom is surrounded by six cyanide ligands which is mono-dentate, the co-ordination number is 6.

Q92. Tertiary alcohols are not oxidized into carbonyl compounds because

• A. They contain more alkyl group
• B. They have no alpha-hydrogen✓
• C. Suitable oxidizing agent is not available
• D. None of the above

Explanation: Tertiary alcohols are not oxidized by acidified sodium or potassium dichromate(VI) solution - there is no reaction whatsoever. During oxidation,oxidizing agent is removing the hydrogen from the -OH group, and a hydrogen from the carbon atom is attached to the -OH. Tertiary alcohols don't have a hydrogen atom attached to that carbon.

Q93. Fe+2 will form the most ionic bonds with:

• A. N-3
• B. S-2✓
• C. P-3
• D. F-1

Explanation: Fe is the symbol for iron (a transition metal), and S is the symbol for sulfur (a nonmetal). When the iron atoms bond with the sulfur atoms, they create a sulfide anion with a charge of 2-, and an iron cation, with a charge of 2+, hence the (II). This compound is used in the stainless steel and iron industries. Fe + S → FeS (heat)

Q94. Which one is more reactive?

• A. HCHO✓
• B. CH3 CHO
• C. (CH3)2CO
• D. Have 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. Which of the following elements has lower first ionization energy?

• A. N
• B. O
• C. C
• D. B✓

Explanation: The first ionization decreases from beryllium to boron, and from magnesium to aluminum, as electrons from the p-block start to come into play. In the case of boron, which has an electron configuration of 1s2 2s2 2p1, the 2s electrons shield the higher-energy 2p electron from the nucleus, making it slightly easier to remove. A similar effect occurs in aluminum, which has an electron configuration of 1s2 2s2 2p6 3s2 3p1. Even though oxygen is to the right of nitrogen in period 2, its first ionization energy is slightly lower than that of nitrogen. Nitrogen has an electron configuration of 1s2 2s2 2p3, which puts one electron in each p orbital, making it a half-filled set of orbitals.Half-filled sets of p orbitals are slightly more stable than those with 2 or 4 electrons, which makes it slightly harder to ionize a nitrogen atom. Oxygen has an electron configuration of 1s2 2s2 2p4, which puts another electron in one p orbital; since this is one electron away from being half-filled, it is slightly easier to remove this additional electron.

Q96. Which one of the following ions has more electrons than protons and more protons than neutrons?

• A. D
• B. d-
• C. H-✓
• D. He

Explanation: H is Hydrogen, it’s proton number is 1 so it has 1 proton, 1 electron and no neutrons. The ion of H gains an electron to attain the negative charge so now it has 2 electrons, 1 proton and 0 neutrons

Q97. A gas decolorized alkaline KMnO4 solution but does not give any PPT with ammoniacal AgNO3

• A. Methane
• B. Ethylene✓
• C. Ethane
• D. None of the above

Explanation: Option d) "None of the above" is incorrect because ethylene (option b) decolorizes KMnO4 but does not give a precipitate with ammoniacal AgNO3. Methane (option a) and ethane (option c) are both saturated hydrocarbons with only single bonds and are not reducing agents, so they would not decolorize KMnO4 or react with ammoniacal AgNO3 to form a precipitate. Therefore, the correct answer is option b) Ethylene.

Q98. Which one of the following elements has the largest second ionization energy

• A. O
• B. F
• C. Na✓
• D. N

Explanation: Na has the largest second ionization energy as the second electron is removed from an inner shell, thus the nuclear charge acting on it is stronger and more energy is needed to remove an electron

Q99. Which of the following species has the maximum number of unpaired electrons?

• A. O2✓
• B. O+2
• C. O-2
• D. O2-2

Explanation: O2 has 2 unpaired electrons, O+2 has no unpaired electrons, O-2 has paired electrons while O2-2 also has no unpaired electrons hence the correct option is A The number of unpaired electrons in an atom or ion can be determined by examining its electron configuration. Let's analyze the given species: 1. **O2**: Molecular oxygen (O2) has a total of 16 electrons (8 electrons per oxygen atom). Its electron configuration is 1s² 2s² 2p⁴. There are two unpaired electrons in the 2p orbital. 2. **O+2**: Oxygen cation (O+2) is formed by losing two electrons from O2. Its electron configuration becomes 1s² 2s² 2p³. There is one unpaired electron in the 2p orbital. 3. **O-2**: Oxygen anion (O-2) is formed by gaining two electrons by O2. Its electron configuration becomes 1s² 2s² 2p⁶. There are no unpaired electrons. 4. **O2-2**: This is a hypothetical species, as it would mean adding two more electrons to O-2, which is not energetically favorable. If you meant O-2, please refer to the explanation for O-2 above. Based on the analysis, **O2** has the maximum number of unpaired electrons with **two unpaired electrons**.

Q100. The oxidation states of Nitrogen in NH4NO3 are

• A. -3 and +5✓
• B. +5 and-3
• C. -3 & -3
• D. Zero

Explanation: NH₄⁺ N + 4 = 1 N = 1-4 N = 3 NO3- N + 3(-2)= -1 N - 6 = -1 N = -1 + 6 N= 5

Q101. Which equation relates to the first ionization energy of bromine?

• A. Br(g) → Br-(g) + 1e
• B. Br(g) → Br+(g) + 1e-✓
• C. 1/2 Br2(g) → Br-(g) + 1e-
• D. 1/2 Br2(g) → Br+(g) + 1e-

Explanation: Refer to folllowing explanation

Q102. Which one is more soluble in water?

• A. Secondary amines✓
• B. Tertiary amines
• C. Quatemary amines
• D. All are insoluble

Explanation: Lower amines can form hydrogen bonds with water thus making them more soluble.

Q103. How many d-block elements are present in the periodic table?

• A. 40✓
• B. 23
• C. 37
• D. 30

Explanation: D-block elements are found from the third group to the twelfth group of the modern periodic table and if you count the total elements of the d-block they are 40. Hence the answer is A.

Q104. Which one of the following is most reactive?:

• A. Benzene
• B. Ethane
• C. Ethene
• D. Ethyne✓

Explanation: Ethyne, also known as acetylene, is the most reactive among the given options due to its triple bond between the carbon atoms. This triple bond is very strong and reactive, making Ethyne a very useful starting material for many organic reactions.

Q105. The decrease in atomic radii is very prominent in the _.

• A. Second group
• B. Second period✓
• C. Higher groups
• D. Higher periods

Explanation: The decrease in atomic radii is very prominent in the second period. As you go across any period the atomic number or proton number increases while electron shielding remains constant which means the nuclear attraction is increasing. Due to increased nuclear attraction, the outermost electrons on the valence shell get attracted by the nucleus hence atomic radii keep decreasing.

Q106. What is the octane number of Iso-octane?

• A. 40
• B. 100✓
• C. Zero
• D. 2

Explanation: Octane number means the ability of any fuel to resist knocking when it is ignited in a mixture of air. N-heptane is a standard liquid that is used for octane number tests but unfortunately, it is a very poor knock resistance and is thus assigned a value of 0. While iso-octane which is also called 2,2,4-trimethylpentane is a very good knock resistance and is assigned a value of 100. So the answer is B.

Q107. More energy is needed to remove an electron from _.

• A. Half filled subshell
• B. Completely Filled Subshell
• C. Partially filled subshell
• D. Both A and B✓

Explanation: Half-filled subshells and completely filled subshells have a symmetrical distribution of electrons e.g. p3 or p6. p3 is a half-filled subshell but the electron distribution is symmetrical; p6 is a completely filled subshell and electrons here are also distributed symmetrically. The more symmetrical distribution, the more stable the element is so more energy is needed to remove an electron from it. So the answer is D.

Q108. What are the shapes of subshells if the value of azimuthal quantum number 'I' is 2?

• A. Spherical
• B. Dumbbell
• C. Complicated✓
• D. All of these

Explanation: When the angular quantum number is equal to 2, the shape of the orbital gets cloverleaf or we can say it gets complicated in shape.

Q109. A crystal is made up of _.

• A. Atoms
• B. Ions
• C. Molecules
• D. All of these✓

Explanation: Every crystalline solid is made up of atoms, ions, and molecules that are arranged in an ordered and symmetrical manner, and this is repeated over the entire crystal. The smallest repeating structure of any solid crystal is a unit cell. Therefore, every crystal is made up of atoms, ions, and molecules. Hence the answer is D.

Q110. What is the formula of chloroform?

• A. CH3Cl
• B. CH2Cl2
• C. CHCl3✓
• D. CH2Cl

Explanation: Chloroform or trichloromethane is an organic compound which has a molecular formula CHCl3. The answer is C.

Q111. In Down cell, the anode is made up of _.

• A. Graphite✓
• B. Copper
• C. Iron
• D. Silver

Explanation: In a Down cell, the anode is made up of graphite. It is made up of graphite so that it does not react with chlorine which is liberated at the anode. Hence answer is A.

Q112. Which one of the following H-bond is strong?:

• A. O-H
• B. N-H
• C. F-H✓
• D. Cl-H

Explanation: This is the strongest hydrogen bond among the options, as fluorine is the most electronegative element, and its small size results in an extremely high degree of electron density and a correspondingly strong attraction to hydrogen.

Q113. Aldehydes and ketones can be obtained by the _.

• A. Reduction of alcohol
• B. Oxidation of alcohol✓
• C. Dehydration of alcohol
• D. Hydrolysis of alcohol

Explanation: Aldehydes can be obtained by the Oxidation of certain primary alcohols, while ketones can be obtained by the oxidation of certain secondary alcohols.

Q114. What is the SI unit of pressure?

• A. Nm-2✓
• B. Nm2
• C. mm of Hg
• D. atm

Explanation: Pressure:Pressure is defined as force per unit area. P = F/ A---> P = N/m^2---> P = Nm^-2 Hence, A is the correct option.

Q115. Which of the following element is present in all proteins?

• A. Sulfur
• B. Carbon
• C. Nitrogen✓
• D. Oxygen

Explanation: Chemically, proteins are complex nitrogenous organic compounds, which are associated with the concept of life itself. By chemical composition, proteins are composed of carbon, hydrogen, oxygen, and nitrogen. Some proteins also contain smaller quantities of sulfur and phosphorus. The percentage of nitrogen is fairly constant and is about 16% of the molecular weight of protein. Hence, C is the correct option.

Q116. In CCl4, all C-Cl bonds are _ but the molecule is overall _.

• A. Polar, Nonpolar✓
• B. Nonpolar, Neutral
• C. Polar, Neutral
• D. Neutral, Nonpolar

Explanation: CCl4, or carbon tetrachloride, contains only polar bonds. The molecule, however, is nonpolar because it has symmetrical geometry. These four equivalent carbon–chlorine bonds generate four dipole moments. These dipole moments cancel each other, and the molecule has no overall polarity. Hence, A is the correct option.

Q117. What is the color of iodoform precipitates?

• A. White
• B. Black
• C. Reddish
• D. Yellow✓

Explanation: This option suggests that the colour of iodoform precipitates is yellow. This statement is correct. Iodoform is a pale yellow solid, and when it precipitates during specific chemical reactions, it appears as yellowish flakes or crystals.

Q118. The molecules of solids possess _ kinetic energy?

• A. Translational
• B. Vibrational✓
• C. Both Options A & B are correct
• D. None of these options are correct

Explanation: Solids are rigid in nature as the particles of solids are held in fixed positions and cannot move freely. They can only vibrate about a mean position and thus transfer energy from one place to another. Thus, molecules of solids possess vibrational kinetic energy.Hence, B is the correct option.

Q119. Falling water of a waterfall is an example of:

• A. Reversible Reaction
• B. Spontaneous Reaction✓
• C. Endothermic Reaction
• D. All of these options are correct

Explanation: OPTION A: The reactions that do not go to completion and the products formed react to re-form the reactants are called reversible reactions. OPTION B: A spontaneous process occurs on its own, without any energy input from the outside. For example, a ball will roll down an incline; water will flow downhill; ice will melt into the water; radioisotopes will decay, and the iron will rust. Hence, B is the correct option. OPTION C: An endothermic reaction takes in energy from the surrounding and the system gains energy, the change in enthalpy, ΔH, is given a positive sign. EXAMPLES: Evaporating liquids, melting ice, dry ice, alkane cracking, thermal decomposition, etc. OPTION D: Incorrect

Q120. Which of the following undergoes "Cannizzaro reaction" ?

• A. Benzaldehyde✓
• B. Acetone
• C. Benzophenone
• D. Benzyl alcohol

Explanation: OPTION A: Aldehydes that have no a -hydrogen atoms undergo Cannizzaro’s reaction. It is a disproportionation (self-oxidation-reduction) reaction. Two molecules of the aldehyde are involved, one molecule is converted into the corresponding alcohol (the reduced product) and the other into the acid in the salt form (the oxidation product). The reaction is carried out with a 50 percent aqueous solution of sodium hydroxide at room temperature. Hence, A is the correct option. OPTION B: In order to perform the Cannizzaro reaction, there must not be any alpha hydrogen, since acetone contains alpha hydrogen that is why acetone cannot undergo the Cannizzaro reaction. OPTION C: Benzophenone is a ketone and donot undergo a Cannizzaro reaction. OPTION D: Read option A.

Q121. Shifting the position of equilibrium can be used to increase:

• A. Temperature
• B. Pressure
• C. Yield of reaction✓
• D. All of these options are correct

Explanation: Changing the position of equilibrium will cause the yield to increase towards the side that counters the change. For example, if the equilibrium position is changed towards the reactant side, more products will be formed to counter the change.

Q122. Which of the following oxidizing agents can oxidize "benzene"?

• A. KMnO4
• B. K2Cr2O7
• C. KHMnO4
• D. V2O5✓

Explanation: Vanadium pentoxide (V2O5) can be used as an oxidizing agent to oxidize benzene and its derivatives under specific conditions. V2O5 is a powerful oxidant commonly employed in organic synthesis. The oxidation of benzene by V2O5 in the presence of air produces maleic anhydride. The oxidation is carried out at 500o C. Hence, D is the correct option.

Q123. Which of following has "higher boiling"and "melting point"?

• A. Acetone
• B. 2 - Butanol✓
• C. Propane
• D. 2 - Methylpropene

Explanation: OPTION A: Acetone has a boiling point of 56.5°C and a melting point of -94.9°C. It is a relatively small molecule and lacks the ability to form hydrogen bonds, resulting in weaker intermolecular forces. OPTION B: 2-butanol has a higher molecular size and the presence of an -OH group, allowing for intermolecular hydrogen bonding. Hydrogen bonding leads to stronger intermolecular forces, resulting in higher boiling and melting points. 2-butanol has a boiling point of 99.5°C and a melting point of -114.5°C. Hence, B is the correct option. OPTION C: Propane (C3H8) is a small molecule with weak London dispersion forces between its nonpolar molecules. It has a boiling point of -42.1°C and a melting point of -187.7°C. OPTION D: 2-methyl propene (also known as isobutylene) (C4H8) is also a small molecule with weak intermolecular forces. It has a boiling point of -6.9°C and a melting point of -159.7°C.

Q124. The increase in atomic radii in _ is due to an increase in the number of shells and the screening effect.

• A. Groups✓
• B. Periods
• C. Both A & B are correct
• D. None of these are correct

Explanation: OPTION A: As we move in a group from top to bottom, the number of shells and the effective nuclear charge increases but the effect of the addition of a new shell dominates over the effect of effective nuclear charge and hence the atomic size increases from top to bottom in a group. Hence, A is the correct option. OPTION B: As we move in a period from left to right, the number of shells remains the same as the electrons are added to the same shell. However, the effective nuclear charge increases and pulls the electron cloud closer to the nucleus. As a result, the atomic size decreases over a period. OPTION C: It is an incorrect option.OPTION D: It is an incorrect option.

Q125. Which of the following solvents favor SN2 reactions?

• A. Water
• B. Ammonia
• C. Carbon tetrachloride✓
• D. Acetic acid

Explanation: OPTIONS A, B, and D: Polar Protic solvents are polar solvents that have at least 1 hydrogen that is connected directly to a particular electronegative atom such as O-H, N-H, etc., and are capable of forming hydrogen bonds with the solute. Here SN1 reactions are faster and SN2 reactions are comparatively slower. Examples of polar protic solvents are water, ethanol, ammonia, HF, acetic acid, etc. OPTION C: The SN2 reaction is favored by polar aprotic solvents. In aprotic solvents, SN2 reactions are faster whereas SN1 reactions are comparatively slow. Polar aprotic solvents are unable to form hydrogen bonds as they do not have any hydrogen atoms bonded with more electronegative atoms like O, N, and F. They do not have acidic protons. Examples of polar aprotic solvents are Acetone, Ethers as well as Chloroform. Carbon tetrachloride (CCl4) has non-polar covalent bonds between carbon and chlorine and is an aprotic solvent. Hence, C is the correct option

Q126. The number of isomers of C4H10 are:

• A. 2✓
• B. 4
• C. 6
• D. 5

Explanation: Butane has two isomers. The two chain isomers of butane (C4H10) are n-butane and isobutane. Hence, A is the correct option

Q127. What is the boiling point of "acetic acid"?

• A. 120°C
• B. 118°C✓
• C. 110°C
• D. 87°C

Explanation: Acetic acid - Latin word (acetum) means ‘vinegar’. Acetic acid is the second simplest carboxylic acid (after formic acid). Acetic acid constitutes about 4-5% of vinegar and has a characteristic smell that is recognizable in vinegar. The boiling point of acetic acid is 118o C. Hence, B is the correct option

Q128. The covalent crystals _ have giant molecules that are insoluble in all the solvents.

• A. Silicon carbide
• B. Diamond
• C. Both options A and B are correct✓
• D. None of these options are correct

Explanation: a) Silicon Carbide (SiC): Silicon carbide is a covalent crystal with a giant molecular structure. It consists of a three-dimensional network of covalently bonded atoms. Due to its strong covalent bonds, silicon carbide is insoluble in all solvents. b) Diamond: A diamond is also a covalent crystal with a giant molecular structure. It is composed of carbon atoms arranged in a tetrahedral lattice through strong covalent bonds. Like silicon carbide, diamond is insoluble in all solvents due to its robust covalent bonding. Therefore, both silicon carbide and diamond, being covalent crystals with giant molecular structures, are insoluble in all solvents, making option c) the correct answer.

Q129. Which of the following is an example of "tertiary alcohols"?

• A. 2-methyl-3-ethylpentane
• B. 3-ethyl-3-hexanol✓
• C. 2-methyl-4-hexanol
• D. Isopropyl alcohol

Explanation: Tertiary alcohols feature a hydroxyl group attached to the carbon atom, which is connected to 3- alkyl groups. 3-ethyl-3-hexanol Hence, B is the correct option. The hydroxyl carbon has three R groups.

Q130. At which temperature will "water" boil at Murree Hills?

• A. 50°C
• B. 100°C
• C. 98°C✓
• D. 67°C

Explanation: Water boils at 98 °C at Murree Hills due to external pressure of 700 torr.

Q131. In "Down Cells", the cathode is made up of:

• A. Graphite
• B. Copper
• C. Iron✓
• D. Inert material

Explanation: The Downs process is a method for the commercial preparation of metallic sodium, in which molten NaCl is electrolyzed in a special apparatus called the Downs cell.The Downs cell uses a carbon anode and an iron cathode.Hence, C is the correct option.

Q132. Under which conditions does a real gas approximate to an ideal gas?

• A. Pressure = high density = high
• B. Pressure = low density = high
• C. Pressure = hight density = low
• D. Pressure = low density = low✓

Explanation: Real gases approximate ideal gas behavior at relatively low density, low pressure, and high temperature. At high temperatures, the gas molecules have enough kinetic energy to overcome intermolecular forces, but at low temperatures, the gas has less kinetic energy and thus the intermolecular forces are more prominent. At low gas densities and low pressures, there is lots of space between molecules, but at high densities, the molecules are crowded and thus the volume of the gas particles is no longer negligible. Lower pressures mean fewer interactions and those interactions can be more easily thought of as elastic collisions. Hence, D is the correct option.

Q133. For the reaction, CO(g) + (1/2)O2(g) ⟶ CO2(g)

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

Explanation: For the reaction. CO(g)+1/2O2(g) = CO2(g) Kp<Kc

Q134. The first ionization energy of an atom depends on:

• A. Charge on nucleus
• B. Screening effect
• C. Electronic configuration
• D. All of the above✓

Explanation: Ionization energy, also called ionization potential is the amount of energy required to remove an electron from an isolated atom or molecule. This energy is usually expressed in kJ/mol. It depends on the charge of the nucleus, shielding effect, and electronic configuration.The greater the charge on the nucleus, the more tightly the outer electrons are held, thus more heat energy is required to remove an electron from the atom.The greater the shielding/screening effect on the outer electrons, the less tightly they are held by the nucleus, thus less energy is required to remove an electron.The greater the distance from the nucleus (the electronic configuration), the lesser the force of nuclear attraction and the higher the ionization energy.

Q135. Chromium compounds in which oxidation state is 6+ behaves as:

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

Explanation: Compounds of chromium which display an oxidation state of +6 are strong oxidizers. Chromium forms several commercially valuable oxygen compounds, the most important of which is chromium oxide, commonly called chromium trioxide or chromic acid, CrO3, in which chromium is in the +6 oxidation state.

Q136. Choose acids that are showing leveling effect. i) HClO4 ii)HI iii) HCI iv) HF

• A. i & iv
• B. i, iii, & iv
• C. iii & iv
• D. i, ii, & iii✓

Explanation: Leveling effect or solvent leveling refers to the effect of solvent on the properties of acids and bases. The strength of a strong acid is limited ("leveled") by the basicity of the solvent. Similarly the strength of a strong base is leveled by the acidity of the solvent Thus H2O is a differentiating solvent for HI HCL HCLO4.HF is a weak acid so it doesn't show levelling effect.

Q137. Colloidal particles can be separated by using:

• A. Ordinary filter paper
• B. Coarse filter paper
• C. Fine Filter paper
• D. Extremely fine filter paper✓

Explanation: Colloidal particles are small solid particles that are suspended in a fluid phase. Their size range is typically between 10nm. Colloidal particles can be separated by a centrifugation method using fine filter.

Q138. The number of chiral centres in a molecular of 5-bromo 3-chloro hexan-2-ol is/are:

• A. 1
• B. 3✓
• C. 2
• D. 5

Explanation: A chiral centre is an atom especially in an organic molecule that has four unique atoms or groups attached to it. To 3 carbons three different functional groups are attached therefore 3 chiral centers are present.Note. To other adjacent carbon don't confuse the fact that 2 H are attached irrespective of different functional groups so they can’t be considered chiral

Q139. Which group when attached to benzene will increase its reactivity:

• A. –NH4+✓
• B. –NH3
• C. –C≡N
• D. –COR

Explanation: Activating groups are Atoms or groups that make the benzene molecule more reactive by increasing the ring's electron density.The resonance structures suggest that the amino group increases the electron density only at ortho- and para-positions of the ring, making them more preferred to the electrophilic attack as they make the benzene more negative thus NH4+ can be used as activating group.

Q140. A particle performs uniform circular motion with angular momentum 'L'. If the frequency of the particle's motion is halved and its KE is doubled then the angular momentum becomes:

• A. L/4
• B. 4L✓
• C. 2L
• D. L/2

Explanation: This is the following solution:

Q141. A sphere of mass 2 kg and radius 5 cm rolls without slipping along a horizontal plane. The velocity of its centre of mass is 10 cm/s. The kinetic energy of the sphere is:

• A. 0.07 J
• B. 0.014 J✓
• C. 0.025 J
• D. 1.25 J

Explanation: This is the following solution:

Q142. Power developed by a person on eating 100g of ice per minute is (Latent heat of ice is 80 cal/g):

• A. 130 W
• B. 560 cal/sec
• C. 560 J/sec✓
• D. none of these

Explanation: A mass of ice eaten by the man per second. m =100/60=5/3 g/s Latent heat of ice, L = 80 cal/g. Therefore, energy required per second by the man in eating the ice, i.e., power developed by the man. = mL =5/3 x 80 cal/s 3 =5x80/3x4.2J/s=560W

Q143. A block hangs freely from the end of a spring. A boy then slowly pushes the block upwards so that the spring becomes strain free. The gain in gravitational potential energy of the block during this process is equal to:

• A. work done by the boy against the gravitational force acting on the block
• B. loss of energy stored in the spring minus the work done by the tension in the spring
• C. work done on the block by the boy plus the loss of energy stored in the spring✓
• D. work done on the block by the boy minus the work done by the tension in the spring

Explanation: Let xo be the initial extension of the spring. Then the initial energy stored in the spring is: ½kxo2 The gain in gravitational potential energy: mgh = mgxo The work done increases the gravitational potential energy and decreases the spring’s potential energy. The total energy gained = gain in the gravitational potential energy - loss in spring’s potential energy. Therefore, work done by the boy (wb) = gain in the gravitational potential energy - loss in spring’s potential From here you can see that the gain in the gravitational potential energy of the block = work done by the boy + loss in the spring’s potential energy. Therefore, option C is the correct one.

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. The angular measurement is known as _ measurement

• A. parameter
• B. area
• C. circumference✓
• D. all of these

Explanation: As θ= Angular displacement or measurement Explanation for this question will be added soon.As θ= Angular displacement or measurement S= arc length or circumference r= radius of circle Since θ= S/r Hence angular displacement is related to circumference or arc length as rhey are directly related.

Q146. A container is filled with oxygen and helium at the same temperature. The molar mass of oxygen is 32 g/mol and that of helium is 4 g/mol. What is the ratio:average speed of oxygen molecules / average speed of helium molecules

• A. 1/√8✓
• B. √8
• C. 1/8
• D. 8

Explanation: Average speed of a molecule is directly proportional to the square root of the temperature at which the gas is kept and indirectly proportional to the molar mass of the gas.FORMULA: √(8RT)/(πM), where R is the universal gas constant (8.3144 J/K mol), T stands for the temperature in kelvins, and M is the molar mass of the molecule.Since the temperature for both gases is same and 8R/π is a constant, therefore the average speed depends inversely on the molar mass of gas.- Let average speed of oxygen be v1 and average speed of helium be v2.Molar mass of oxygen (m1) = 32 g/molMolar mass of helium (m2) = 4 g/molUsing the formula:v1 / v2 = √m2/m1v1 / v2 = √4/32v1 / v2 = √1/8Therefore the ratio of average speed of oxygen molecules and helium molecules is option A ( 1 : ✓8 ).

Q147. If f1 and f2 are frequencies of two tuning forks, such that f1 < f2, then number of beats produced in one second are:

• A. f2 - f1✓
• B. f2 x f1
• C. f1 - f2
• D. f2 + f1

Explanation: If the two waves are in phase t=0, they will be in phase when the first wave has gone through exactly one more cycle than the second. This will happen at a time t=T, the period of the beat.Let n be the number of cycles of the first wave in time T, then the number of cycles of the second wave at the same time is (n-1). Hence, T = Nt1 = (n-1)T1.

Q148. A spring of force constant 800 N/m has an extension of 5 cm, the work done in extending it from 5 cm to 15 cm

• A. 16 J
• B. 8 J✓
• C. 32 J
• D. 24 J

Explanation: Work done is found using the formula = ½ x k x [(extension 1)^2 - (extension 2)^2]= ½ x 400 x [(0.15)^2 - (0.05)^2]= 8 J

Q149. System in thermodynamics is disconnected with surrounding by

• A. Pressure
• B. Universe
• C. Boundary✓
• D. Temperature

Explanation: A boundary is defined as a closed surface surrounding a system through which energy and mass may enter or leave the system whereas everything external to the system is the surroundings.

Q150. A cyclist is travelling at 15 ms-1, she applies brakes so that she doesn't collide with the wall in front of her at a distance of 18 m. Calculate the magnitude of deceleration.

• A. 6.3 ms-1✓
• B. 5.3 ms-1
• C. 13 ms-1
• D. 12.5 ms-1

Explanation: Initial velocity, u=15m/sFinal velocity, v=0m/sDistance, s=18mAcceleration, a=?Using relation, v2 −u2 =2as02 −(15)2 =2a×18−225=36aa= 36 −225 ​ =−6.25m/s2So, deceleration is 6.25m/s2 which is equal 6.3m/s2

Q151. At every point of the trajectory of projectile, which of the following quantities is always zero?

• A. Horizontal velocity
• B. Total velocity
• C. Vertical accelaration
• D. Horizontal acceleration✓

Explanation: Projectile motion can be analyzed by breaking it down into horizontal and vertical components. In the absence of air resistance, the horizontal velocity of a projectile remains constant throughout its trajectory, and there is no horizontal acceleration. The vertical motion of a projectile is affected by gravity, so there is a constant vertical acceleration throughout the motion. However, at the highest point of the trajectory, the vertical velocity of the projectile becomes zero before changing direction and starting to move downward. Therefore, neither the vertical velocity nor the total velocity is always zero throughout the trajectory. Thus, the only quantity that is always zero throughout the projectile's trajectory is the horizontal acceleration.

Q152. Infrasonic waves have a frequency of:

• A. Greater than 20000 Hz
• B. Less than 20 Hz✓
• C. 20 Hz
• D. Greater than 20 Hz

Explanation: Infrasonic waves are waves with frequencies below the human audible range i.e. 20-20000 Hz

Q153. A body of mass 5 kg, projected at an angle of 45° from the ground covers a horizontal range of 45 m. The acceleration due to gravity is g = 10 m/s^2. What is the velocity with which it was projected?

• A. 22.5 m/s
• B. 20 m/s
• C. 19.8 m/s
• D. 21.21 m/s✓

Explanation: Explanation is given below.

Q154. Two wave sources are oscillating in phase. Each source produces a wave of wavelength 𝜆. The two waves from the sources meet at point 𝑋 with a phase difference of 90°.What is a possible difference in the distances from the two wave sources to point 𝑋?

• A. 𝜆/8
• B. 𝜆/4✓
• C. 𝜆/2
• D. 𝜆

Explanation: The two given sources are in phase . A distance equal to the wavelength corresponds to a phase difference of 360,this means that they are in phase .When two things are in phase it infers that they have no phase difference. This shows us that a phase difference of 90 corresponds to a distance equal to /4.

Q155. The sound waves of frequency more than 20 khz are termed as:

• A. Supersonic
• B. Audible
• C. Infrasonic
• D. Ultrasonic✓

Explanation: Ultrasonic waves are sound waves whose frequencies are higher than those of waves normally audible to the human ear. ultrasonics, vibrations of frequencies greater than the upper limit of the audible range for humans—that is, greater than about 20 kilohertz.

Q156. The voltage in the primary and the secondary coils of a step-up transformer are 200V and 4KV respectively. If the current in the primary is 1 ampere then the current in the secondary coil will be

• A. 50mA✓
• B. 5A
• C. 500mA
• D. 1.5mA

Explanation: Explanation is giving below:

Q157. The wavelength associated with an electron is of the order of:

• A. Visible light
• B. X rays✓
• C. Radio waves
• D. Infrared

Explanation: X-rays are commonly produced by accelerating(or deccelerating) charged particles; examples include a beam of electrons in a synchrotron particle accelerator or storage ring.In addition,highly excited atoms can emit X-rays with discrete wavelengths characteristic of the energy level spacings in the atoms.The X-ray region of electromagnetic spectrum falls far outside the range of visible wavelengths.

Q158. One kilowatt-hour is commonly termed as one commercial unit of electric energy which is equal to:

• A. 3.6 x 10^5 j
• B. 3.6 x 10^6 j✓
• C. 3.6 x 10^4 j
• D. 3.6 x 10^3 j

Explanation: 1kWh=3.6 x 10^6J as a matter of fact.

Q159. One of the following is an Ohmic device:

• A. Filament bulb
• B. Semiconductor diode
• C. Transistor
• D. Copper wire✓

Explanation: Filament bulbs, thermistors and semiconductor diodes are non-ohmic materials while metals are ohmic devices or substances.

Q160. If a half wave rectifier is used to convert 50Hz AC into DC, then the number of pulses present in rectified voltage is:

• A. 25
• B. 50✓
• C. 100
• D. 75

Explanation: Rectifiers produce unidirectional and pulsating voltage from A.C. source, the number of pulses per second in the rectified voltage remains same as that of input voltage, i.e., here it is 50 Hz.

Q161. In which rectifier is the ripple factor less?

• A. Full wave✓
• B. Half wave
• C. Both A and B
• D. None of them

Explanation: Lower the value of the ripple factor higher will be the efficiency of the rectifier. As we know that half-wave rectifier is less efficient as compared to a full-wave rectifier, hence, its ripple factor is greater than that of a full-wave rectifier and its value is 1.21.

Q162. The output voltage of a rectifier is:

• A. Smooth
• B. Pulsating✓
• C. Perfectly direct
• D. Alternating

Explanation: A rectifier is used to convert alternating current to pulsating direct current not smooth direct current. Perfectly direct current will have fixed magnitude and fixed direction of current. This is not true for the output of a rectifier. Hence, option B is correct.

Q163. If λv, λx and λm represent the wavelengths of visible light, X-rays and microwaves respectively, then:

• A. λm > λx > λv
• B. λm > λv > λx✓
• C. λv > λx > λm
• D. λv > λm > λx

Explanation: The electromagnetic spectrum is generally divided into seven regions, in order of decreasing wavelength and increasing energy and frequency. The decreasing order of the wavelengths of electromagnetic waves would be; radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV) light, X-rays, and gamma-rays. Hence the correct answer would be λm>λv>λx

Q164. Which of the following statements about electromagnetic waves is/are correct? (1) X-rays in vacuum travel faster than light waves in vacuum. (2) The energy of X-ray photon is greater than that of a light photon (3) Light can be polarised but X-ray cannot.

• A. 1 and 2
• B. 2 and 3
• C. 1, 2 and 3
• D. 2 only✓

Explanation: Since X-ray is an electromagnetic wave they travel with same speed of light in the vacuum that is 3x106 m/s

Q165. A TV tower has a height of 100m. The average population density around the tower is 1000 per km2 . The radius of the earth is 6.4x106 m. × The population covered by the tower is

• A. 2x106
• B. 3x106
• C. 4x106✓
• D. 6x106

Explanation: This is the following solution:

Q166. The diode used in the circuit shown in the figure has a constant voltage drop of 0.5 V at all currents and a maximum power rating of 100 milliwatts. What should be the value of the resistor R, connected in series with the diode, for obtaining maximum current?

• A. 1.5 Ω
• B. 5 Ω✓
• C. 6.67 Ω
• D. 200 Ω

Explanation: This is the following solution:

Q167. The valence band and conduction band of a solid overlap at low temperature, the solid may be:

• A. a metal✓
• B. a semiconductor
• C. an insulator
• D. none of these

Explanation: According to band theory of solids, in the valence band and the conduction band overlap in conductors.

Q168. According to coulomb's law, the electrostatic forces of attraction between electron and nucleus are _ to its square of the radius.

• A. Directly proportional
• B. Inversely proportional✓
• C. Equal
• D. None of these options are correct

Explanation: Coulomb's law states that the force of attraction or repulsion acting along a straight line between two electric charges is directly proportional to the product of the charges and inversely to the square of the distance between them.

Q169. Which two or more of the following actions would increase the energy stored in a parallel plate capacitor when a constant potential difference is applied across the plates?

• A. Decreasing the area of the plates. Decreasing the separation between the plates
• B. Decreasing the area of the plates. Increasing the separation between the plates Inserting a dielectric between the plates
• C. Increasing the area of the plates. Decreasing the separation between the plates. Inserting a dielectric between the plates✓
• D. Increasing the area of the plates. Increasing the separation between the plates

Explanation: The energy is directly proportional to the area, so as the area increases, the energy will increaseThe energy is inversely proportional to the distance, so as the distance decreases, the energy will increaseThe energy increases if the value of k increases (that is, if a dielectric is put between the plates)

Q170. The frame of reference could be:

• A. Fixed always
• B. Not fixed always✓
• C. At rest
• D. None of these

Explanation: Option B is correct since there can be two frames of reference and they are not fixed.Option A is incorrect since the frames of reference can change depending upon the position of the observer.Option C is incorrect since the inertial frame of reference is moving at a constant velocity and the non-inertial frame of reference is accelerating.Option D is incorrect since it states none of these which is not the case.

Q171. The transverse nature of light is shown by

• A. Interference of light
• B. Refraction of light
• C. Polarization of light✓
• D. Dispersion of light

Explanation: A light wave is an electromagnetic wave which travels through the vacuum of outer space and transparent materials like glass. Electromagnetic waves are transverse waves in the sense that the plane of the wave vibrations is different from the plane of wave propagation. The electromagnetic waves in the true sense have the direction of propagation perpendicular to the direction of its electric and magnetic fields. In the case of polarized waves, the electric and magnetic fields are also at right angles to each other. Polarized light waves are electromagnetic waves in which the vibrations occur in a single plane. Light can be polarized by transmission, reflection, refraction or scattering. Using a polaroid filter, different planes of vibration of polaroid filters can be blocked due to the special material used there. Due to the polarization of light, it is evident that light is a transverse wave.

Q172. A car battery has EMF of 12 volts and internal resistance 5x 10-2 ohm. If it draws 60 ampere current, then terminal voltage of the battery will be:

• A. 5 volts
• B. 3 volts
• C. 15 volts✓
• D. 9 volts

Explanation: Here the terminal potential: V=12+Ir 12+(60×5×10−1) 12+3=15V

Q173. 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​

Q174. A metal cube with sides of length “𝑎” has electrical resistance 𝑅 between opposite faces. What is the resistance between the opposite faces of a cube of the same metal with sides of length 3𝑎?

• A. 9𝑅
• B. 3𝑅
• C. R/3✓
• D. 𝑅/9

Explanation: the resistance can be found by the relation R=pL/A p(resistivity) In this case L=a and A=a2 soR=p 1/aWhen L=3a then A=9a2So R=p 1/3a Hence 1/3 times

Q175. 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.

Q176. Tesla is unit of _ per unit area:

• A. Magnetic field lines✓
• B. Electric field lines
• C. Optical field lines
• D. Gravitational field lines

Explanation: The tesla (T) is the unit of magnetic flux density also called magnetic B-field strength. One tesla is equal to one weber per square meter. Using the equation , where E or magnetic flux density is equal to magnetic flux/ Area, (magnetic flux means magnetic field lines). Magnetic flux density (E) has units tesla and magnetic field lines have unit weber.

Q177. The resistance of a device is designed to change with temperature. What is the device?

• A. A light dependent resistor
• B. A potential divider
• C. A semiconductor diode
• D. A thermistor✓

Explanation: The resistance of a device thermistor is designed to change with temperature. The resistance of a device is designed to change with temperature. What is the device.

Q178. A cell of internal resistance 2.0Ω and electromotive force (e.m.f) 1.5V is connected a resistor of resistance 3.0Ω. What is the potential difference across the 3.0Ω resistor?

• A. 5V
• B. 1.2V
• C. 0.9V✓
• D. 0.6V

Explanation: 5 Ohms share 1.5 V, so each Ohm gets 0.3 V.So 3 Ohms gets 3 x 0.3 = 0.9 V.

Q179. Work function for a certain surface is 3.3 ev. Minimum frequency, light must have in order to eject electron from surface will be:

• A. 8 x 1014 Hz✓
• B. 3.2 x 1015 Hz
• C. 4.8 x 1015 Hz
• D. 6.4 x 1015 Hz

Explanation: The correct option is A.To calculate the minimum frequency of light required to eject an electron from a surface, we need to use the formula:f = (W/E)where f is the minimum frequency, W is the work function, and E is the energy of a photon of light.Since the work function is given as 3.3 eV, we first need to convert it to joules using the conversion factor 1 eV = 1.6 x 10^-19 J:W = 3.3 eV x 1.6 x 10^-19 J/eV = 5.28 x 10^-19 JThe minimum energy of a photon required to eject an electron is equal to the work function, so we have:E = W = 5.28 x 10^-19 JNow we can plug in these values into the formula and solve for f:f = (W/E) = (5.28 x 10^-19 J) / (6.63 x 10^-34 J s) = 7.97 x 10^14 Hzwhich is approximately equal to 8 x 10^14 Hz. As it is numerical, it can have only one answer.

Q180. The decay constant λ of a radioactive sample

• A. Decrease as the age of atoms increase
• B. Increase as the age of atoms increase
• C. Is independent of the age✓
• D. Depends on the nature of activity

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

Q181. 1 radian is equal to:

• A. 57.1 degrees
• B. 57.2 degrees
• C. 57.3 degrees✓
• D. 57.4 degrees

Explanation: 360 degrees = 2 π rads-> 1 radian= 360/2π->57.3 degrees.

Q182. In transmission from grid station, power losses are minimized by:

• A. Decreasing current
• B. Decreasing resistance.
• C. Increasing resistance
• D. Increasing voltage✓

Explanation: Efficient transmission involves reducing the currents by stepping up the voltage prior to transmission, stepping it down at the far end when the current has reached its destination.For AC power transmission, the stepping up and down of the voltage is done using transformers.

Q183. The domestic electricity supply has a frequency of:

• A. 150 Hz
• B. 100 Hz
• C. 50 Hz
• D. 25 Hz✓

Explanation: The domestic electricity supply has a frequency of 50 Hz in Pakistan.

Q184. PIV stands for :

• A. Positive inverse voltage
• B. Pawn Bh Integrated voltage
• C. Peak inverse voltage✓
• D. Peak integrated voltage

Explanation: Peak Inverse Voltage (PIV) or Peak Reverse Voltage (PRV) refer to the maximum voltage a diode or other device can withstand in the reverse-biased direction before breakdown. Also may be called Reverse Breakdown Voltage.

Q185. 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.

Q186. Which photon carries the most energy?

• A. Blue
• B. Violet✓
• C. Red
• D. Green

Explanation: VIBGYOR From left to right: Wavelength increases. Frequency decreases. Energy(hf) decreases ->-> so energy decreases from violet to red. Maximum energy is that of violet.

Q187. Which of the following series lies in the ultraviolet range:

• A. Balmer series
• B. Pashcher series
• C. Lyman series✓
• D. Brackett series

Explanation: The Lyman series lies in the UV region.Balamer series lies in visible region.Paschen series lies in the near IR region.Brackett series lies in in MID IR region.The Pfund series lies in the region far IR region.

Q188. The main difference between X rays and Y rays is:

• A. Frequency
• B. Wave length
• C. Energy
• D. Origin✓

Explanation: The main difference is of the origin. X-rays are emitted by electrons outside the nucleus whereas, the gamma rays are emitted by the excited nucleus again making the origin, the sole difference.

Q189. There are initially 400 atoms in a radioactive sample. What would be the number of atoms after 3 half - life?

• A. 400
• B. 200
• C. 50✓
• D. 25

Explanation: After each half-life the number of radioactive sample becomes half. First Half Life: 400->200 Second Half life: 200->100 Third Half life: 100->50.

Q190. While using radiation therapy, cancerous thyroid is treated with _ radioisotope:

• A. Carbon
• B. 235 Uranium
• C. Thorium
• D. Iodine - 131✓

Explanation: Radioactive Iodine(also called RAL) can be used to treat thyroid cancer.

Q191. In what form is the energy stored in a charged capacitor?

• A. gravitational
• B. electrical potential✓
• C. magnetic field
• D. potential

Explanation: Energy is stored in a form of electrostatic field between plates of capacitor. This energy can be expressed in the form of work done by the battery.

Q192. Ohm multiplied by farad is equivalent to:

• A. Time✓
• B. Charge
• C. Distance
• D. Capacitor

Explanation: The formula for charging and discharging capacitor is RC=T R: resistance C: capacitance T: time for charging/ discharging

Q193. Iodine-131 is used to trace which cancer

• A. lungs
• B. thyroid gland✓
• C. breast
• D. liver

Explanation: Your thyroid gland absorbs nearly all of the iodine in your body. Because of this, radioactive iodine (RAI, also called I-131) can be used to treat thyroid cancer.

Q194. Directions: In the following question, a number sequence is given with one term missing. Choose the correct term that will continue the same pattern and replace the question mark in the given sequence. 2,6,18,54,162,?

• A. 486✓
• B. 324
• C. 243
• D. 450

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

Q195. Directions: Read the following information and give answer. A rat runs 20' towards East and turns to right, runs 10' and turns to right runs 9' and again turns to left, runs 5' and then turns to left, runs 12' and finally turns to left and runs 6' Now, which direction is the rat facing?

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

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

Q196. In this section of logical deduction, the question consists of a brief passage (usually a report containing certain data regarding some social or economic problem), followed by certain inferences based on it. The student is required to analyze the contents (or data) of the passage and grasp the desirable facts from it. Then, student has to consider each of the given inferences in the context of the given passage. decide upon its degree of truth or falsity and then choose the hest alternative provided accordingly. The water resources of our country are very much underutilized. The main reason of this underutilization is the lack of capital and technology. A large portion of our water resources is wasted due to floods and unwise use of water for irrigation as well as domestic purposes. We can make full use of our water resources by building dams on rivers and by adopting policy of awareness among people not to waste water. Some people do not use water resources in a judicious way.

• A. Definitely true✓
• B. Probably true
• C. Data inadequate
• D. Probably false
• E. Definitely false

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

Q197. Statements: Some blankets are beds. Some pillows are blankets. All beds are pillows. Conclusions: I. Some blankets are pillows. II. Some pillows are beds. III. Some beds are blankets. Which of the following is/are most appropriate in the above scenario?

• A. Only I
• B. Only II
• C. Only II and III
• D. I, II and III✓

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

Q198. Statements: I. There is an unprecedented increase in the number of young unemployed in comparison to the previous year.II. A large number of candidates submitted applications against an advertisement for the post of manager issued by a bank.

• 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 effects of independent causes

Explanation: An increase in the number of unemployed youth is bound to draw in huge crowds for a single vacancy.

Q199. Dependent causes/ Independent causes:Statement: There has been a high increase in the incidents of atrocities against women in the city during the past few months. The police authority has been unable to nab the culprits who are committing crimes against women.

• 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 the statements I and II are independent causes✓
• D. Both the statements I and II are effects of independent causes

Explanation: There has been a high increase in the incidents of atrocities against women in the country during the past few years is a true statement. The police authority has been unable to nab the culprits committing crimes against women. It is also true.Both the sentences stated above are about the same subject but of independent causes.