Etea Mdcat 2012 — Solved Past Paper with Answers

Q1. When you go to Karachi,please

• A. Collect a good watch for me.
• B. Acquire a good watch for me.
• C. Bring a good watch for me.✓
• D. Arrange a good watch for me.

Explanation: Collect means gather together(A number of things). OPTION B:Acquire means learn or develop (a skill,habit,or quality). OPTION C:Bring means to take or carry someone or something to a place or a person, or in the direction of the person speaking: OPTION D:Arrange means organize or make plans for(a future event).

Q2. Why have you broken this jug? The passive form of the sentence is:

• A. Why has this jug been broken by you?✓
• B. Why have this jug been broken by you?
• C. Why this jug has been broken by you?
• D. Why had that jug been broken by you?

Explanation: This sentence is in the present perfect tense.In passive voice, we use Has/Have +Object+ been +3rd form of verb+by+subject+?

Q3. Remember to brush your teeth after dinner, "she said. The indirect form of the sentence is:

• A. She told him to remember to brush his teeth after dinner.
• B. She reminded him to brush his teeth after dinner.✓
• C. She advised him to remember to brush his teeth after dinner
• D. She said to him to remember to brush his teeth after dinner.

Explanation: Indirect Speech = Reported Speech Indirect speech differs from direct speech in that we DO NOT tell exactly what another person said. We are NOT repeating what someone else said. John says: I’m a good boy. We say: John said he was a good boy.

Q4. You did not kill a lion in the forest Passive form of the sentence as:

• A. A lion is not killed by you in the forest.
• B. A lion was not killed by you in the forest.✓
• C. A lion is killed not by you in the forest.
• D. A lion has not killed by you in the forest

Explanation: This is past indefinite negative sentence.In passive voice we use Object +was/were+not+3rd form of verb+by+subject.

Q5. Mathematics …. difficult but fascinating.

• A. seems✓
• B. is seeming
• C. seemed
• D. seem

Explanation: Some nouns are deceptive; they are singular. i.e: Physics,News,Sports,Politics etc. With singular nouns, we use singular verbs. Singular verbs:goes,plays,writes Plural verbs:go,play,write.

Q6. Please come to the point; don‘t beat _ the bush.

• A. across
• B. about
• C. along
• D. round✓

Explanation: Please come to the point,don’t beat about the bush.

Q7. She has complained _ me to the principal.

• A. about
• B. from
• C. against✓
• D. over

Explanation: Against means in opposition to (someone or something).

Q8. I said to him, "Can you read this letter?"‘ Indirect form of the sentence is:

• A. I said to him whether he read that letter.
• B. I asked him if could he read this letter.
• C. I told him that he could read that letter.
• D. I asked him if he could read that letter.✓

Explanation: Indirect Speech = Reported Speech Direct speech in English is a type of speech when we retell someone’s speech as it was. We don’t change anything. John says: I’m a good boy. To tell what John said, We say: John said, “I’m a good boy.” Indirect speech differs from direct speech in that we DO NOT tell exactly what another person said. We are NOT repeating what someone else said. John says: I’m a good boy. We say: John said he was a good boy. If the Reported Speech in Direct Narration is introduced by Verbs like “ be”, “have”, “do”, or any other auxiliary Verbs like “can”, “shall”, “will”, the connective “ if ”, “ whether ” is used after the Reporting Verb or object of the Reporting verb in the Indirect Narration.

Q9. If you want to play cricket,

• A. you ought to join our club.✓
• B. you ought to join with our club.
• C. you ought joined our club.
• D. you ought to join in our club.

Explanation: you ought to join our club is the accurate one. 'Ought' to come before another verb and after the subject.

Q10. Allah, the Almighty, has blessed him_ a son.

• A. by
• B. along
• C. from
• D. with✓

Explanation: 'with' is the most suitable preposition. 'With' means ‘in the same place as someone or something’ or ‘accompanying’ As in the above statement, 'with' is used as a meaning of accompanying.

Q11. You need to go to the hospital _ possible. An erratic heartbeat can be very dangerous.

• A. as good as
• B. as long as
• C. as much as
• D. as soon as✓

Explanation: 'as soon as possible' is the most suitable option. As we use 'as soon' to show that something happens immediately.

Q12. Ghani Khan is_ of Pashto.

• A. John Keats
• B. a John Keats
• C. the John Keats✓
• D. like John Keats

Explanation: Generally, we don't use the article 'THE' with a proper noun but if the proper noun is used as a symbol as in our question, we use the article 'THE' with a proper noun.

Q13. Did he buy a car yesterday? The passive form of the sentence is:

• A. Was a car bought by him yesterday?✓
• B. Has a car been bought by him yesterday?
• C. Is a car bought by him the other day?
• D. Had a car been bought by him yesterday?

Explanation: The given sentence is from the past indefinite tense. The following rules are considered to convert active voice into passive voice Convert the object of the Active Voice Sentence into the subject of the Passive Voice Sentence. Use the helping verb was/were according to the subject of the Passive Voice sentence. Use 3rd form of the verb. Then, use the word “by”.

Q14. Choose the correct sentence out of the following:

• A. Each of them deserves praise
• B. Each one of them deserves praise
• C. Each one of them deserve praise
• D. Every one of them deserves praise.✓

Explanation: The word 'each' refers to individual things within a group of two or more. While each can be used for two or more groups, 'Every' refers to groups of at least three items. Additionally, everyone refers to the collective whole, not just the individuals.

Q15. Choose the correct sentence out of the following;

• A. The meeting does not approve in your scheme.
• B. The meeting do not approves of your scheme.
• C. The meeting does not approve of your scheme.✓
• D. The meeting does not approve about your scheme

Explanation: We use does with third-person singular pronouns i.e. when the subject is he, she, or it.

Q16. He said to me, ―May you succeed in life!"The indirect form of the sentence is:

• A. He said to me that may you succeed in life
• B. He prayed that I might succeed in life.✓
• C. He prayed that he might succeed in life
• D. He prayed that you may succeed in life

Explanation: While reporting imperative sentences we use reporting verbs like ask, request, beg, order, advise, wish, etc to match the mood of the sentence.

Q17. They arrived at about midnight

• A. because their flight was detained.
• B. because their flight was delayed.✓
• C. because their flight was derailed.
• D. because their flight was diverted.

Explanation: Here 'delayed' is suitable because in the question it is mentioned that they arrived late by actual time.

Q18. If it did not rain in time, there _ a horrible famine.

• A. would have been
• B. will be
• C. would be✓
• D. will have been

Explanation: For instance, using "would". To use "would", you could rephrase the concept as an "if-then" statement. Using "will" denotes an amount of certainty, or a high degree of confidence in the statement. But "would" statements do not essentially indicate any serious differentiation.

Q19. Glycolysis completes with the net gain of:

• A. 2 ATP✓
• B. 3 ATP
• C. 4 ATP
• D. 32 ATP

Explanation: Glyco-Glucose Lysis-Splitting The breakdown of glucose is called glycolysis. In the glycolytic pathway,4 molecules of ATP are produced.2 ATP molecules are produced when triose bisphosphate is converted to triose phosphate, and the other two are produced when phosphoenolpyruvate is converted to pyruvic acid. Hence, a total of 4 ATP molecules are formed during glycolysis. 2 molecules of ATP are utilized in glycolysis. One molecule of ATP is utilized when glucose is converted to glucose-6-phosphate and the other is utilized when fructose-6-phosphate is converted to fructose-1,6-bisphosphate So, the net gain of ATP molecules during glycolysis is 2.

Q20. Restriction enzymes are of great use in genetic engineering because:

• A. They cut DNA at the specific base level✓
• B. They cut DNA at several specific levels
• C. They help in binding the pieces of DNA
• D. They are nuclease

Explanation: Restriction enzymes are DNA-cutting enzymes. Each enzyme recognizes one or a few target sequences and cuts DNA at or near those sequences. Restriction enzymes are found in bacteria (and other prokaryotes). They recognize and bind to specific sequences of DNA, called restriction sites.

Q21. Abscisic acid promotes:

• A. Triple response
• B. Sex expression
• C. Flower initiation
• D. Leaf, flower, and fruit fall✓

Explanation: Abscisic acid is a plant hormone that acts as a plant inhibitor. It promotes the fall of various plant parts like leaves, flowers, and fruits.

Q22. Surplus amino acids in the body are broken down to form urea in:

• A. Spleen
• B. Kidneys
• C. Liver✓
• D. Pancreas

Explanation: Deamination and urea formation is a major function of the liver. Deamination of amino acids is mainly done by the liver (separation of amino group of amino acid and its conversion to ammonia). The preparation of urea from the amino acids is done by the liver. The liver converts ammonia (obtained from deamination) into urea through the ornithine cycle. So, after the damage or spoilage of the liver, the ammonia level in the animal's body is increased and the animal dies.

Q23. Lipids are chemically

• A. Acids
• B. Alcohols
• C. Ethers
• D. Esters✓

Explanation: Lipids are esters of long-chain fatty acids and alcohol.

Q24. Which of the following represents the bile salts?

• A. Bilirubin✓
• B. Biliverdin
• C. Haemoglobin
• D. Both (A) and (B)

Explanation: Bile is a fluid that is made and released by the liver and stored in the gall bladder. Bile contains mostly cholesterol, bile acids, and bilirubin (A breakdown product of red blood cells). Bile salts are a primary component of bile and are needed by the body to help break down fats, aid digestion, absorb important vitamins, and eliminate toxins.

Q25. The conversion of excess glucose into fat is known as:

• A. Glycolysis
• B. Lipogenesis✓
• C. Ketogenesis
• D. Glycogenesis

Explanation: The conversion of excess glucose into fat is known as lipogenesis.

Q26. Fatigue-free muscles are:

• A. Striped
• B. Unstriped
• C. Cardiac✓
• D. Triceps

Explanation: Cardiac muscles are involuntary muscles that do not fatigue.

Q27. Excretion of bile pigments in blood indicates:

• A. Anaemia
• B. Diabetes
• C. Rickets
• D. Jaundice✓

Explanation: Jaundice is a condition in which skin, whites of the eyes, and mucous membranes turn yellow due to high levels of bilirubin (A yellow-orange bile pigment).

Q28. An individual with contrasting alleles is called

• A. Homozygous
• B. Monoecious
• C. Heterozygous✓
• D. Dioecious

Explanation: An organism having two different alleles for a character or trait is called Heterozygous i.e. (Tt).

Q29. The color of bone marrow is:

• A. Red
• B. Yellow
• C. Orange
• D. Both (A) and (B)✓

Explanation: Many bones contain a soft tissue called bone marrow, which can be either red or yellow.

Q30. Enzymes are basically

• A. Proteins✓
• B. Carbohydrates
• C. Hydrocarbons
• D. None of the above

Explanation: Enzymes are globular proteins that speed up a biochemical reaction.

Q31. A non-connective tissue is:

• A. Areolar tissue
• B. Tendon
• C. Neuron✓
• D. Ligament

Explanation: Neurons are cells that constitute the nerve tissues.

Q32. Speech and language areas are located in:

• A. Thalamus
• B. Medulla oblongata
• C. Right cerebral hemisphere
• D. Left cerebral hemisphere✓

Explanation: The left cerebral hemisphere assists in language, logical reasoning, and comprehension.

Q33. Phytochromes are involved in:

• A. Photorespiration
• B. Photophosphorylation
• C. Photoperiodism✓
• D. Phototropism

Explanation: Phytochrome is a type of photoreceptor that plants use to detect light. They are sensitive to light for the red and far-red regions of the visible spectrum. It is only involved in photomorphogenesis responses, seed germination, bud dormancy, synthesis of gibberellin and ethylene, and photoperiodism.

Q34. A botanist who proposed the cell theory was:

• A. Schlelden✓
• B. Schwann
• C. Robert Hook
• D. Robert Brown

Explanation: The cell theory was proposed by a German botanist, Matthias Schleiden, and an English zoologist, Theodor Schwann, but in the above question, they asked about the botanist so option A is correct.

Q35. Smooth endoplasmic reticulum makes:

• A. Enzymes
• B. Protein
• C. Sugar
• D. Lipids✓

Explanation: The main function of smooth endoplasmic reticulum is to make cellular products like lipids. Which stores this lipid as adipose tissue and liver cells also process toxins.

Q36. How many atoms of oxygen in R.N.A. are greater than D.N.A.?

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

Explanation: The difference of O2 in RNA to DNA is only one oxygen and the enzymes need to recognize DNA and RNA.

Q37. Growth promoting substance in plant is:

• A. F.A.D
• B. Chlorophyll a
• C. I.A.A✓
• D. ABA

Explanation: I.A.A includes auxins which stimulate the production of root hairs and lateral roots and release saccharides from plant cell walls during the elongation which contributes to the plant growth and development.

Q38. Steroid hormones are produced by:

• A. Testes and ovaries
• B. Adrenal glands and gonads
• C. Adrenal cortex and gonads✓
• D. Gonads and thyroids

Explanation: Steroid hormones produced from the adrenal cortex are mineralocorticoids, glucocorticoids, and androgens. Steroid hormones produced by gonads are androgens, estrogens, and progesterone.

Q39. B.C.G vaccines are usually given to:

• A. Children✓
• B. Adults
• C. Special persons
• D. All of the above

Explanation: The vaccine Bacillus Calmette Guerin (BCG) is given to children, who have the risk of coming into contact with TB, where TB rates are high.

Q40. Proteins, carbohydrates, and fats form three great classes of foodstuffs commonly called:

• A. Trivirates
• B. Triumvirates✓
• C. Trisvirates
• D. All of the above

Explanation: Triumvirates means a group of three working together. Protein, carbohydrates, and fats are used for energy.

Q41. Replication of D.N.A occurs in:

• A. Inter phase✓
• B. Prophase
• C. Metaphase
• D. Anaphase

Explanation: In interphase, the synthesis or replication of DNA takes place in the nucleus i.e. each chromosome duplicates into two sister chromatids.

Q42. Regeneration of cartilage is carried on by:

• A. Collagenous fibers
• B. Blood vessels
• C. Perichondrium
• D. Matrix✓

Explanation: Matrix is a network of proteins and other molecules, which helps cells attach to, and communicate with nearby cells and plays an important role in cell growth, cell movements, and other cell functions. Matrix is also involved in repairing damaged tissues.

Q43. Nuclear mitosis occurs in the kingdom of:

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

Explanation: In nuclear mitosis, the nuclear membrane remains the same, and mitotic spindles form within the nucleus then the nuclear membrane pinches between the two clusters of daughter chromosome. Nuclear mitosis occurs only in fungi.

Q44. The sense of hearing is concerned with:

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

Explanation: The cerebrum acts as a control center for sight, smell, taste, speech, and hearing.

Q45. The largest lymphatic duct is the:

• A. Abdominal duct
• B. Thoracic duct✓
• C. Femoral duct
• D. Subclavian duct

Explanation: The largest lymphatic duct is the thoracic duct. It is approximately 40 cm in length and 5 mm in width.

Q46. In human being, the number of cranial nerves are:

• A. 8 pairs
• B. 10 pairs
• C. 12 pairs✓
• D. 31 pairs

Explanation: The nerves which arise from the brain are called cranial nerves or cerebral nerves. In human beings there are 12 pairs of cranial nerves among which three are sensory, five are motor, and four are mixed nerves.

Q47. Live attenuated vaccines are used to treat all of the following diseases except:

• A. Typhoid and plague
• B. Polio and measles
• C. Cholera and rabies✓
• D. Mumps and influenza

Explanation: Live attenuated vaccines use a weakened form of the virus, which can still grow and replicate, but does not cause illness. Inactivated vaccines contain viruses whose genetic material has been destroyed by heat, chemicals, or radiation so they cannot infect cells and replicate, but can still trigger an immune response.

Q48. All of the following are polysaccharides except:

• A. Lactose
• B. Cellulose
• C. Starch
• D. Glucose✓

Explanation: Glucose is a monosaccharide that can't be hydrolyzed.

Q49. A single ovum of a human being contains:

• A. X — chromosomes✓
• B. XX — chromosomes
• C. YY — chromosomes
• D. XY — chromosomes

Explanation: The ovum (Egg) is a haploid cell and contains an X chromosome.

Q50. In a dihybrid cross, how many homozygous offsprings can be produced?

• A. 4✓
• B. 3
• C. 2
• D. 9

Explanation: In a dihybrid cross, four homozygous offspring are produced RRYY (Round Yellow) rryy (Wrinkled Green) RRyy (Round Green) rrYY (Wrinkled Yellow)

Q51. In the human beings, the carrier of color blind is:

• A. Male
• B. Female✓
• C. Both male and female
• D. None of them

Explanation: Color blindness is an X-linked recessive trait. It is non-allelic and its carrier is female. It travels from maternal grandfather to grandson through mother. A female having one recessive gene on X-chromosome is a carrier female, while a female possessing both recessive genes on both X-chromosomes will be color-blind which is very rare.

Q52. The number of ATP formed directly by a single Krebs cycle is:

• A. One ATP✓
• B. Two ATP
• C. 32 ATP
• D. 36 ATP

Explanation: The number of ATP during a single Krebs cycle is 1. Krebs cycle occurs 2 times for one Glucose molecule.

Q53. Myoglobin combines with:

• A. Four oxygen molecules
• B. Three oxygen molecules
• C. Two oxygen molecules
• D. One oxygen molecule✓

Explanation: Myoglobin is muscle hemoglobin and has a tertiary structure.i.e.contains one polypeptide chain so it can bind with one oxygen molecule. On the other hand, hemoglobin has a quaternary structure and four polypeptide chains. So, it can bind with four oxygen molecules.

Q54. Sunken stomata are present in:

• A. Hydrophytes
• B. Xerophytes✓
• C. Mesophytes
• D. All of the above

Explanation: Sunken stomata are the stomata that are embedded into leaf layers rather than on the leaf surface. Xerophytes face the problem of shortage of water so they have sunken stomata to prevent water loss.

Q55. Which blood group transfusion can be made without risk?

• A. Group A to Group B
• B. Group AB to Group O
• C. Group A to Group O
• D. Group B to Group AB✓

Explanation: Blood transfusions are done according to the following basic principle. Antigens of the donor react with the antibodies of the recipient. Since the AB blood group is a universal recipient, it can receive blood from the B blood group.

Q56. Haemophilia affects males more than females because of:

• A. Dominant autosomes
• B. Dominant X- linked
• C. Recessive X- linked✓
• D. y- chromosome linked

Explanation: A woman can only suffer from hemophilia A or B in homozygous recessive condition whereas a man with just one recessive allele will display the trait. Thus a man has double the chances to suffer from hemophilia A and B than a woman.

Q57. Penicillin is obtained from:

• A. Penicillium notatum✓
• B. Aspergillus fumigatus
• C. Aspergillus flavus
• D. Penicillium chrysogenum

Explanation: Explanation: Penecillin is an antibiotic that is produced by the fungus Penecillium notatum. The discovery of penecillin by Alexander Fleming in 1928 was a major breakthrough in the treatment of bacterial infections. Aspergillus fumigatus is a species of fungus that can cause a variety of infections in humans, but it is not a source of penecillin. Aspergillus flavus is another species of fungus that can produce toxins that contaminate food crops, but it is not a source of penecillin. Penecillin chrysogenum is another species of fungus that can produce penecillin, but Penecillin notatum is the more commonly used species for commercial production.

Q58. Insulin is produced by:

• A. Alpha-cells
• B. Beta-cells✓
• C. Delta-cells
• D. Gamma-cells

Explanation: Beta cells are concerned with insulin production.

Q59. Chlorophyll a and b chiefly absorb:

• A. Violet blue light
• B. Orange light
• C. Blue—red light✓
• D. Red, orange light

Explanation: Chlorophyll a and b absorbs blue and red light. Blue is at the high-energy end of the spectrum, so light of this wavelength is responsible for this much excitation and explains the absorption peak in blue. Red wavelengths are lower in energy and only boost the electron to a lower energy level than can blue light. Green light is not absorbed but reflected, making the plant appear green.

Q60. The following nasal passages are composed of cartilage except:

• A. Trachea
• B. Bronchus
• C. Bronchioles✓
• D. Tracheoles

Explanation: Bronchioles lack supporting cartilage skeletons and have a diameter of around 1 mm. They are initially ciliated and graduate to the simple columnar epithelium and their lining cells no longer contain mucous-producing cells.

Q61. A set of xylem tissues are:

• A. Vessels, tracheids, parenchyma✓
• B. Sieve tubes, companion cells, fibers
• C. Parenchyma, sieve tube, vessels
• D. Fibers, companion cells, tracheids

Explanation: Xylem consists of tracheids, vessels, parenchyma, and fibers. Phloem tissue consists of conducting cells, generally called sieve elements, parenchyma cells, companion cells, fibers, and sclereids. Hence, A is the correct option.

Q62. The interval of pacemaker signals from S.A.N to A.V.N is:

• A. 01 second
• B. 0.1 second✓
• C. 02 seconds
• D. 0.2 second

Explanation: The wall between the atria and ventricles has a high resistance, so the electrical current can only pass to the ventricles through one specialized part of the septum called the atrioventricular node (AVN) - this passes on the wave of conduction to the ventricles after about 0.1s, causing a delay.

Q63. A Test cross is:

• A. Tt × Tt
• B. Tt × tt✓
• C. TT × Tt
• D. TT × TT

Explanation: A test cross is a cross between an individual with an unknown genotype with a homozygous recessive genotype. It is used to know whether the dominant trait is heterozygous or homozygous.

Q64. Carotenoid contains:

• A. Carotenes
• B. Xanthophylls
• C. Chlorouhyil – C
• D. Both (A) and (B)✓

Explanation: The carotenoids belong to the isoprenoids and their basic structure is made up of eight isoprene units, resulting in a C-40 backbone. Formally, two types of carotenoids can be discerned: Carotenes are pure hydrocarbons while xanthophylls are derivatives that contain one or more oxygen functions.

Q65. The attraction of water molecules to the xylem vessels is called:

• A. Adhesion✓
• B. Cohesion
• C. Collision
• D. Corrosion

Explanation: Adhesion is a molecular attraction between “unlike” molecules. In the case of the xylem, adhesion occurs between water molecules and the molecules of the xylem cell walls.

Q66. Tobacco is a:

• A. Long day plant
• B. Short day plant✓
• C. Day-neutral plant
• D. Intermediate plant

Explanation: Short-day plants require a long period of darkness and a short period of light to flower. These flowers in the spring season e.g., rice, tobacco, cotton. A short-day plant would flower when the dark period in its daily cycle exceeds 9 hours.

Q67. Ripening of fruits can be promoted by:

• A. Gibberellic acid
• B. Indole acetic acid
• C. Flsrcen
• D. Ethylene gas✓

Explanation: Ethylene is a plant hormone. It is also called a ripening hormone as it is responsible for the ripening of fruits. Fruit ripening is accompanied by an increased rate of respiration. Due to increased respiration, complex carbohydrates are broken down into simpler sugars and the cell wall becomes soft. It inhibits cell division.

Q68. The diameter of the human capillary is:

• A. 5 microns
• B. 6 microns
• C. 7 microns
• D. 8 microns✓

Explanation: The capillaries are about 8 to 10 microns (a micron is 0.001 mm) in diameter, just large enough for red blood cells to pass through them in a single file. The single layer of cells that form their walls are endothelial cells, like those that form the smooth channel surface of the larger vessels.

Q69. The least toxic excretory product is:

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

Explanation: According to the species, nitrogenous waste substances such as ammonia, urea, or uric acid are produced during protein metabolism. A small amount of nitrogenous waste substances are also produced during the metabolism of nucleic acids. Ammonia is the most toxic, followed by urea and then uric acid.

Q70. Organisms phenotypically similar but genotypically different are said to be:

• A. Monozygous
• B. Homozygous
• C. Heterozygous✓
• D. Multizygous

Explanation: Heterozygous – Organisms phenotypically similar but genotypically different.

Q71. Gibberellin was isolated from:

• A. An algae
• B. A fungus✓
• C. A bacterium
• D. A virus

Explanation: Gibberellins were first isolated from the fungus Gibberella fujikuroi, the cause of the foolish seedling disease of rice.

Q72. The process of bone formation is called:

• A. Calcification
• B. Chondrification
• C. Decalcification
• D. Ossification✓

Explanation: Bone ossification, or osteogenesis, is the process of bone formation. This process begins between the sixth and seventh weeks of embryonic development and continues until about age twenty-five; although this varies slightly based on the individual.

Q73. The Bicep muscle is attached to the humerus by:

• A. Tendon✓
• B. Ligaments
• C. Elastic fibers
• D. Areolar

Explanation: The biceps is attached to the arm bones by tough connective tissues called tendons.

Q74. The concentration of water molecules is inversely proportional to the:

• A. Water potential
• B. Pressure potential
• C. Solute potential✓
• D. Osmotic potential

Explanation: Osmosis occurs according to the concentration gradient of water across the membrane, which is inversely proportional to the concentration of solutes. Osmosis occurs until the concentration gradient of water goes to zero or until the hydrostatic pressure of the water balances the osmotic pressure.

Q75. The target organ for vasopressin is:

• A. Heart
• B. Liver
• C. Stomach
• D. Kidneys✓

Explanation: Vasopressin regulates the tonicity of body fluids. It is released from the posterior pituitary in response to hypertonicity and causes the kidneys to reabsorb solute-free water and return it to the circulation from the tubules of the nephron, thus returning the tonicity of the body fluids toward normal.

Q76. Thirst is controlled by:

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

Explanation: The pituitary gland releases AVP when the amount of water in the body becomes too low. It helps retain water in the body by reducing the amount of water lost through the kidneys, making the kidneys produce more concentrated urine.

Q77. Auxins inhibit the growth of:

• A. Apical buds
• B. Lateral buds✓
• C. Parthenocarpy
• D. Root growth

Explanation: Auxin inhibits the growth of lateral axillary buds (apical dominance). It inhibits the growth of lateral buds and promotes the growth of terminal buds. Hence, increasing the length of the plant.

Q78. Redox action takes place during the process of:

• A. Respiration
• B. Photosynthesis
• C. Growth
• D. Both A and B✓

Explanation: An oxidation-reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between two species. So, the redox reaction takes place in cellular respiration and Photosynthesis. Photosynthesis is a mechanism in which chlorophyll-containing plants turn carbon dioxide into sugars through a series of redox reactions in the presence of sunlight.

Q79. How many genotypes will be produced by crossing two alleles "A" and "a"?

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

Explanation: By crossing two alleles “A” and “a”, the possible genotypes are AA, Aa, and aa. Hence, three genotypes are possible.

Q80. A bacterium that converts NO2 to NO3 is:

• A. Rhizobium
• B. Bacillus
• C. Nitrosomonas
• D. Nitrobacter✓

Explanation: During the process of nitrification, Nitrobacter converts nitrite into nitrate.

Q81. Methanoic acid HCOOH has one carbon-oxygen bond of length 123 PM and another of 136 PM. The C = O and C-O bond lengths respectively would be:

• A. 136 PM, 123 PM
• B. 123 PM and 136 PM✓
• C. 136 PM, 136 PM
• D. 123 PM and 123PM

Explanation: The explanation is given below.

Q82. Choose the compound in which hydrogen bonding is not possible.

• A. CH3OCH3✓
• B. H2O
• C. CH3CH2OH
• D. CH3COOH

Explanation: A hydrogen bond is a bond between a highly electronegative atom ( F, O, N, etc ) and hydrogen. For hydrogen bonds to occur hydrogens need to be bonded to an electronegative atom such as oxygen or fluorine. Since CH3OCH3 has no O-H bonds, it cannot form H-bonds.

Q83. Benzene undergoes substitution reactions more easily than addition reactions because:

• A. of its cyclic nature
• B. of having three double bonds
• C. of aromatic character
• D. of delocalization of electrons✓

Explanation: Benzene is a very stable molecule. This stability is due to delocalization of pi electrons therefore, benzene undergoes electrophilic substitution reactions and is less reactive towards electrophilic addition reactions.

Q84. The ring test is shown by compounds having:

• A. Sulphate radical
• B. Chloride radical
• C. Nitrate radical✓
• D. None of the above

Explanation: The brown ring test is used for the detection of nitrate ions in a solution. Nitrate is formed by the ring test.

Q85. Which is the strongest acid?

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

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

Q86. Ozone is:

• A. Greenish, tasteless, light gas
• B. Blue-green, and bitter in taste
• C. Blue, poisonous, and explosive gas
• D. Purple-yellow, poisonous, and nonexplosive gas✓

Explanation: Ozone (O3) is a gas molecule composed of three oxygen atoms. Often called "smog," ozone is harmful to breathe. Ozone aggressively attacks lung tissue by reacting chemically with it. Ozone is a colourless or pale blue gas.

Q87. Rectified spirit is:

• A. 100% ethanol
• B. 95% ethanol✓
• C. 90 % ethanol
• D. 35% ethanol

Explanation: Rectified spirit also known as neutral spirits is highly concentrated ethanol that has been purified using repeated distillation in a process called rectification. Rectified spirit is 95% Ethanol + 5% Water.

Q88. Lucas Test is used to detect the presence of:

• A. Alcohols✓
• B. Phenols
• C. Amino acids
• D. Carboxylic acids

Explanation: Lucas test is used to detect the presence of alcohol.

Q89. Choose the correct statement:

• A. The human body does not produce Enzymes
• B. The human body does not produce Vitamins✓
• C. Proteins are energy source for our body
• D. Nucleic acids are building blocks for our body

Explanation: Vitamins are organic compounds which have to be obtained from the diet, either because an organism does not have the enzymes necessary to synthesize them or because it cannot produce them in sufficient quantities.

Q90. Na2B4O7 10 H20 is the formula of:

• A. Bauxite
• B. Borax✓
• C. Carborundum
• D. Colemanite

Explanation: Na2B4O7 10 H20 is the formula of Borax. (FACT)

Q91. 1 amu is equal to 1.661 × 10-24g, then 1.0 g will be equal to:

• A. 6.022 × 10^23 amu✓
• B. 6.022 × 10^-23 amu
• C. 6.022 × 10^-24 amu
• D. 6.022 × 10^24 amu

Explanation: As 1 a.m.u is equal to 1.66 x 10^-24 g conversely 1 gram is equal to 6.022 x 10^23 amu. For example: 1 carbon atom = 12 amu 1 mole of carbon = 12 g 6.022 x 10^23 C atom = 12 g 1 C atom / 12 = 1 amu 6.022 x 10^23 C atom / 12 = 6.022 x 10^ 23 amu As written above: 6.022 x 10^23 = 12g, we will right like that, 12g/12 = 6.022 x 10^23 Hence , 1g = 6.022 x 10^23

Q92. For a certain chemical reaction, the slope of the plot was determined and plotted against the concentration (a — x)2, and a straight line was obtained. It indicates that the reaction is of:

• A. First order
• B. Second order✓
• C. Third order
• D. Zero-order

Explanation: If the slope of the plot of a certain chemical reaction is determined and plotted against the concentration (a - x)^2, and a straight line is obtained, it indicates that the reaction is of second order.

Q93. One mole is the amount of substance that contains as many elementary entities as contained in:

• A. 0.12 kg of 6C12
• B. 1.2 kg of 6C12 atom
• C. 0.012 kg of 6C12 atom✓
• D. 0.12 kg of 8O16

Explanation: One mole is the amount of substance that contains as many elementary particles as 12g of C12 isotope of carbon. So, if we convert 12 g of Carbon 12 into kilograms by dividing the mass value by 1000 we will get 0.012 kg of C12.

Q94. Select the chemical method used for the determination of the reaction rate:

• A. Conductometry
• B. Polarimetry
• C. pH meter
• D. Volumetric analysis✓

Explanation: Volumetric analysis is a quantitative analytical method that is used widely. As the name suggests, this method involves the measurement of the volume of a solution whose concentration is known and applied to determine the concentration of the analyte. This method is used for determining reaction rate.

Q95. Bakelite is obtained from:

• A. Adipic acid and hexamethylenediamine
• B. Dimethyl terephthalate and ethyl glycol
• C. Neoprene
• D. Phenol and formaldehyde✓

Explanation: Bakelite is obtained from the condensation reaction of phenol and formaldehyde.

Q96. Consider the following endothermic reaction: N2(g) + O2(g) → 2NO(g). What will happen to the equilibrium if the temperature of the system is raised?

• A. The equilibrium will shift the backward
• B. The equilibrium position will suffer no change
• C. The equilibrium will shift in the forward direction✓
• D. All of the above

Explanation: In an endothermic reaction, an increase in temperature shift the equilibrium to the right which means the equilibrium will shift in the forward direction or towards the product side and increases the amount of product. And as a result, the value of Kc is increased.

Q97. Why it is so that if aromatic compounds are burned In the air, produce a very smoky flame?

• A. An aromatic compound cannot be completely converted into CO2 and other products during burning
• B. The available amount of oxygen present in the air is not sufficient to completely burn the available compound✓
• C. Aromatic compound produces compounds on burning that is of black color
• D. None of the above

Explanation: Aromatic compounds contain more carbon per weight than aliphatic and will require more oxygen to burn off all the carbon into carbon dioxide. This will require a more flow of oxygen and a higher temperature. If both of these are met, you will get a normal flame and if it is not met, you will get a smoky flame. OR Because they have an excess of carbon in them. Carbon remains unburnt due to the incomplete combustion in the limited supply of air (oxygen) which give a smoky flame.

Q98. Acetic acid reacts with methanol in the presence of an acid catalyst to give:

• A. Methyl formate
• B. Ethyl formate
• C. Methyl acetate✓
• D. Ethyl acetate

Explanation: Acetic acid is also known as ethanoic acid. So, the reaction of methanol and acetic acid yields methyl ethanoate/methyl acetate. This process is known as Esterification.

Q99. Select the strongest reducing agent:

• A. Cl^ – 1
• B. Ne
• C. Na+
• D. Ca+2✓

Explanation: Calcium ion is the strongest reducing agent because it undergoes easy oxidation by losing electrons. Metals are very good reducing agents, since they strongly tend to donate electrons when combining. From among the metals listed, choose the one that is the most reactive (that is, which is the most easily oxidized = which is the best reducer). Examining their electronegativities, as given in the “info boxes” in the relevant Wikipedia articles, will be a big help. (Hint: lowest electronegativity = highest metallic reactivity.)

Q100. CH4 on complete oxidation in the presence of Cu as catalyst under 200 atm yield:

• A. Methanol✓
• B. Formaldehyde
• C. Formic acid
• D. Carbon dioxide gas

Explanation: The complete oxidation of methane at 200atm in the presence of copper catalyst forms methyl alcohol or methanol. CH4 + [O] → CH3OH

Q101. The solids in which the molecules or ions are arranged in a regular repetitive manner are called:

• A. Amorphous solids
• B. Glassy solids
• C. Polymers
• D. Crystals✓

Explanation: The solid in which its atoms, molecules, or ions are arranged in a regular arrangement is called a crystalline solid. They are repeated in a three-dimensional pattern with a highly ordered throughout the crystal e.g. sodium chloride etc.

Q102. Compared to benzene, nitration of toluene takes place at:

• A. slower rate
• B. faster rate✓
• C. same rate
• D. depends on the conditions

Explanation: Compared to benzene, nitration of toluene takes place at a faster rate. This is because in toluene, the (-CH3) group attached to the benzene ring highly activates the benzene ring through hyperconjugation and it becomes Ortho, para director which has more reactivity towards nitration as compared to benzene.

Q103. Sodium hydroxide acts on Aluminum oxide to form:

• A. NaAlO3
• B. Na3Al2O6
• C. NaAlO2✓
• D. NaAl2O3

Explanation: When sodium hydroxide acts on aluminium oxide it forms sodium aluminate and water. NaOH + Al2O3 → NaAlO2 + H2O

Q104. The alpha bond formed between carbon and oxygen atoms in aldehyde and ketone is due to the overlap of:

• A. sp2 — sp
• B. sp2 — sp2✓
• C. sp3 — sp2
• D. sp — sp

Explanation: The carbonyl carbon in aldehyde and ketone forms sp2 hybridization, as the carbon and oxygen atoms form a sigma bond in the molecule by overlapping the sp2 hybrid orbitals.

Q105. Paper is a biodegradable material. It produces gas whose emission is environmentally objectionable. Which is that gas?

• A. CO2✓
• B. SO2
• C. CH4
• D. NO2

Explanation: When paper is burned oxygen from the air combines with carbon and hydrogen in the paper turning some of it into carbon dioxide and water vapor.

Q106. How many sigma bonds are there in CH2 = CH – CH = CH2

• A. 6
• B. 9✓
• C. 11
• D. 4

Explanation: 9 is correct. As 1st carbon makes two sigma bonds with hydrogen = 2 sigma bonds 2nd carbon makes one sigma bond with hydrogen = 1 sigma bond 3rd carbon makes one sigma bond with hydrogen = 1 sigma bond 4th carbon make two sigma bond with hydrogen = 2 sigma bonds And three sigma bonds are present between the carbons = 3 sigma bonds So, 2+1+1+2+3= 9 sigma bonds

Q107. The cracking problem of fuel combustion can be avoided by:

• A. reforming
• B. improving octane number
• C. adding TEL
• D. All of the above✓

Explanation: Option A: The conversion of straight-chain hydrocarbons into branched-chain by heating in the absence of oxygen and the presence of a catalyst is called reforming (a technique used to increase the octane number) Option B: As the octane number increases, the engine is less likely to produce knocking.i.e.burns smoothly in internal engine Option C: Tetraethyl lead is an efficient antiknock agent to increase the octane number. Hence, option D is correct.

Q108. Select the compound that will give a Positive iodoform test:

• A. Benzaldehyde
• B. 2-Pentanone✓
• C. 3-Hexanone
• D. 3-Pentanone

Explanation: In the case of carbonyl compounds, only those compounds give an iodoform test that has an alpha methyl group and give an oxidation reaction. 2-Pentanone has an alpha methyl group and gives an oxidation reaction as well.

Q109. Ethene and Ethyne can be distinguished by employing the test:

• A. Br2 in organic solvent
• B. Baeyer‘s reagent
• C. Phenyl Hydrazine
• D. Tollen‘s reagent✓

Explanation: Ethene doesn't react with Tollen's reagent while Ethyne forms white ppt.

Q110. Which is true about London forces?

• A. London forces are present in non-polar molecules
• B. London forces are present in polar molecules
• C. London forces are created between instantaneous dipole and induced dipole
• D. All of the above.✓

Explanation: London dispersion forces are present in all types of molecules but are more significant in non-polar molecules. It is a very short-lived force as it is present between instantaneous dipole and induced dipole.

Q111. The correct electronic configuration of Nickel (28) is:

• A. 1s2 2s2 2p6 3s2 3p6 3d8 4s2✓
• B. 1s2 2s2 2p6 3s2 3p6 3d7 4s2 4p1
• C. 1s2 2s2 2p6 3s2 3p6 3d6 4s2 4p2
• D. 1s2 2s2 2p6 3s2 3p6 3d6 4s1 4p3

Explanation: According to Aufbau Principle, "electrons fill lower-energy atomic orbitals before filling higher-energy ones". Hence, A is the correct option.

Q112. Select the correct equilibrium constant expression, Kc for the following reversible reaction. Ce4+(aq) + Fe2+(aq) → Ce3+(aq) + Fe3+(aq)

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

Explanation: Equilibrium constant is a constant ratio of product concentration to reactant concentration.It is only applicable to gases and aqueous solution. There is no Kc for solids.

Q113. Bohr predicted the radius of the orbit of the electron in the hydrogen atom to be: If the electron moves from n = 1 to n = 2, by how many times the radius of the orbit will increase?

• A. 2 times
• B. 3 times✓
• C. 4 times
• D. 5 times

Explanation: Since r = n^2 (0.053nm) When n = 1 r1 = 0.053nm When n = 2 r2 = 2^2 (r1) r2 = 4 r1 An increase in the radius of orbit when an electron moves from n=1 to n=2 is given as 4r1 - r1 = 3r1 ( 3 times increase)

Q114. The volume occupied by 3.2 g of oxygen at STP is:

• A. 22.4 dm3
• B. 2.24 dm3✓
• C. 11.2 dm3
• D. 16.0 dm3

Explanation: 1 mole of Oxygen= 32g The volume occupied by one mole of oxygen gas = 22.414 dm^3 The volume occupied by 3.2g of Oxygen= 32/10 = 22.414/10 Thus, the volume occupied by 3.2g of Oxygen= 2.214dm^3

Q115. Which of the following elements with a given electronic configuration has the highest ionization potential value?

• A. 1s2 2s2 2p3✓
• B. 1s2 2s2 2p4
• C. 1s2 2s2 2p6 3s1
• D. 1s2 2s2 2p6 3s2 3p3

Explanation: Ionization energy is the amount of energy required to remove an electron from an isolated gaseous atom to form a cation. Ionization energy decreases down the group because it is easy to remove electrons from large-size atoms. Similarly, the ease of removing the Electron is given as Partially filled orbital > Half filled orbital > completely filled orbital Removing an electron from a half-filled p orbital of Nitrogen is difficult. Therefore, A is the correct option.

Q116. Which one is not responsible for the formation of acid rain?

• A. CO2
• B. SO2
• C. CO✓
• D. NO2

Explanation: Acid rain is caused by the dissolution of oxides into the water molecules of rain in the atmosphere. The oxide dissolves in the water and forms acid. The acid rain is corrosive. To determine which compounds do not contribute to acid rain, we need to check which ones won't convert into acid after reacting with oxygen and moisture in the atmosphere. Carbon monoxide does not react with water to form an acid. So, it would not contribute to acid rain. Hence, C is the correct option.

Q117. Which of the following hybridization can explain the the shape of BeCl2?

• A. sp2 hybridization
• B. sp hybridization✓
• C. sp3 hybridization
• D. dsp2 hybridization

Explanation: It's very simple ….the hybridization is sp …as there are no lone pairs with beryllium and the number of bond pair are 2…hence the only hybridization that is possible for it is 'sp'. The formula is = number of bond pair + number of lone pair For any sort of molecule just put the number of lone pair and bond pair with the central atom in this simple formula you will get your answer. e.g. BeCl2 = number of lone pair+number of bond pair =0+2=2 Hence there are only two hybrid orbitals, one s and one p orbital i.e. sp hybridization, and the structure would be linear. Cl—Be—Cl

Q118. According to Millikan‘s oil drop experiment, the charge on an oil droplet is:

• A. Quantized
• B. Integral multiple of 'e‘
• C. Not less than 'e‘
• D. All of them✓

Explanation: The minimum charge that exists in the universe is equal to the charge of an electron i.e. - 1.6 × 10^-19 which is quantized. Similar is the case with an oil droplet, its charge is equal to an electron or integral multiple of electron which is quantized.

Q119. The enthalpy of the elements at 1 atm: pressure and 298 K is arbitrary given the value of:

• A. 0.1
• B. 1.0
• C. 29.8
• D. Zero✓

Explanation: The enthalpies of the elements in their standard states are arbitrarily assumed to be zero at 298K and 1 atm because the is no change involved in their formation.

Q120. Select the correct statement about lattice energy:

• A. The energy absorbed when 1 mole of ionic crystal Lattice is formed from its constituent ions in the gaseous state.
• B. The energy liberated when 1 mole of an ionic crystal Lattice is formed from its constituent ions in the gaseous state✓
• C. The energy liberated when 1 mole of an ionic crystal Lattice is split into its constituent ions in the gaseous state
• D. None of the above

Explanation: The bond formation is an exothermic process (energy is given out). Bond breaking is an endothermic process (energy is absorbed) Thus, when one mole of an ionic crystal lattice is formed, energy is liberated and not absorbed.

Q121. Which of the following compounds on treatment with NaHCO3 will liberate CO2?

• A. CH3COOH✓
• B. C2H5NH2
• C. CH3COCH3
• D. CH3CH2OH

Explanation: Only Carboxylic acids liberate Carbon dioxide on treatment with NaHCO3. CH3COOH is a carboxylic acid and liberates CO2 on treatment with NaHCO3.

Q122. Commonly used coagulant used for the purification of water is:

• A. Ca(NO3)2
• B. MgCl2
• C. Al2(SO4)3✓
• D. Ca(OH)2

Explanation: In water treatment, coagulants are used to remove a wide variety of hazardous materials from water, ranging from organic matter and pathogens to inorganics and toxic materials, like arsenic, chemical phosphorous, and fluoride. Aluminum sulfate is the most commonly used inorganic chemical for coagulation in wastewater treatment.

Q123. Which compound is formed when Ammonium hydroxide is added to silver chloride?

• A. [Ag (NH3)2 ] Cl✓
• B. [Ag (NH3)}Cl
• C. [Ag (NH3)4) Cl
• D. [Ag (NH3)6] Cl

Explanation: Silver chloride is a white crystalline solid with molecular formula AgCl. It is well known for its low solubility in water. Ammonium hydroxide (NH4OH)commonly known as ammonia or ammonia water is a solution of ammonia in water. Silver chloride reacts with ammonium hydroxide and yields diamine, silver chloride, and water. Silver chloride is sparingly soluble in ammonia but dissolves in an excess of concentrated ammonia solution due to Le Chatelier's principle. Even though silver chloride very small solubility product value, some free silver ions are present in the solution, which in addition to concentrated ammonia solution effectively consumes the free silver ion, as ammonia which is a good σ-electron pair donor ligand combines with the silver ion. Silver chloride reacts with ammonium hydroxide and yields diamine, silver chloride, and water.

Q124. Which one is a spontaneous chemical reaction?

• A. Zn + Cu2+ → Zn+2 + Cu✓
• B. Zn2+ + Cu → Cu2+ + Zn
• C. 2 Fe (OH)3 → 2 Fe + 3/2 O2 + 3 H2O
• D. 2NaCl → 2Na + Cl2

Explanation: A chemical reaction that is exothermic and has an increasing disorder is certain to result in a spontaneous reaction. Since the reaction is exothermic, ΔH is negative. Since the disorder increases, ΔS is positive. The oxidation of Zn(s) into Zn2+ and the reduction of Cu2+ to Cu(s) occur spontaneously. In other words, the redox reaction between Zn and Cu2+ is spontaneous.

Q125. Which one of the following will give an ionic product?

• A. CH3CH2OH + PCI5 →
• B. CH3CH2OH + Na →✓
• C. CH3CH2OH + PCI3 →
• D. CH3CH2OH + 5oCl →

Explanation: When sodium reacts with alcohol it leads to the formation of sodium alkoxide which is salt and leads to the evaluation of hydrogen gas.

Q126. Which of the following can function as Lewis acid?

• A. CN
• B. NH3
• C. CH3 – O – CH3
• D. I+✓

Explanation: Lewis acid is defined as an electron pair acceptor. I+ (iodine cation) can act as a Lewis acid because it has an incomplete octet in its valence shell. Lewis acids are electron pair acceptors, meaning they have an electron-deficient center that can accept lone pair electrons from a Lewis base.

Q127. All amino acids found in proteins are:

• A. ɑ-amino acids✓
• B. β-amino acids
• C. Both ɑ and β
• D. None of the above

Explanation: All the amino acids that constitute proteins and are coded in the genome are alpha-amino acids; Although hundreds of amino acids exist in nature, by far the most important is the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code.

Q128. Which is a trimer of ethyne?

• A. PVC
• B. Benzene✓
• C. Toluene
• D. Teflon

Explanation: Benzene is a cyclic trimer of ethyne. Trimer is also a polymer that has 3 constituent units or monomers.

Q129. Which is NOT true about amino acids?

• A. They have two functional groups
• B. They show both acidic and basic characteristics
• C. They are the basic units of proteins
• D. They do not exist in solid state✓

Explanation: This is called a zwitterion. This is the form that amino acids exist in even in the solid state. Due to its existence in the form of zwitterion, there exists a very strong intermolecular attraction which is responsible for the high melting point of amino acids.

Q130. Which is the least polar molecule?

• A. HF
• B. HI✓
• C. HCI
• D. HBr

Explanation: To investigate the polarity of diatomic molecules, we investigate the difference, if any, in the electronegativities of the elements of the two atoms. Generally, the greater the difference, the greater the polarity of the molecule. In HI, the electronegativity of the Hydrogen atom is 2.2 and the electronegativity of the Iodine atom is 2.66, so the electronegativity difference is 0.46.

Q131. Ketones are prepared by the oxidation with Na2Cr2O7 and H2SO4 of:

• A. Primary alcohol
• B. Secondary alcohol✓
• C. Tertiary alcohol
• D. All of the above

Explanation: On oxidation of secondary alcohol gives ketones. On reduction of ketones gives secondary alcohols. CH3-CH(OH)-CH3+[O] reacts with acidified K2Cr2O7 gives,CH3-CO-CH3+H2O (acetone)

Q132. Which of the following is a condensation polymer?

• A. Nylon 6,6✓
• B. Teflon
• C. Polypropylene
• D. Orlon

Explanation: Condensation polymers are any kind of polymers whose process of polymerization involves a condensation reaction (i.e. a small molecule, such as water or methanol, is produced as a byproduct). Several synthetic condensation polymers discussed include nylon, kevlar, polyester, Bakelite, melamine, polycarbonates, polyurethanes, and epoxies.

Q133. Which of the following statement is NOT true?

• A. Condyloid joint is triaxial✓
• B. Synovial fluid reduces friction
• C. Coronal suture is for parietal and frontal bone articulation
• D. Synostosis is a bony joint

Explanation: Condyloid joints, also known as ellipsoid joints, are composed of an egg-shaped bone known as a condyle that fits into a similarly shaped cavity. Hence is not a ball and socket kind of structure that is known as axial.

Q134. The ionization potential of Hydrogen atom is:

• A. 13.6 V✓
• B. 1.36 V
• C. 10.2 V
• D. 4.3 V

Explanation: The ionization potential is the quantity of energy that an isolated, gaseous atom in the ground electronic state must absorb to discharge an electron, resulting in a cation. The ionization potential of hydrogen atom is 13.6eV (2.18 × 10−18 joule).

Q135. In which of the following compounds hydrogen bonding is possible?

• A. PH3
• B. CH4
• C. NH3✓
• D. SiH4

Explanation: Any molecule which has a hydrogen atom attached directly to an oxygen or nitrogen is capable of hydrogen bonding. Hydrogen bonds also occur when hydrogen is bonded to fluorine, but the HF group does not appear in other molecules.

Q136. Sucrose sugar is considered as:

• A. Monosaccharide
• B. Oligosaccharides✓
• C. Polysaccharides
• D. All of the above

Explanation: Sucrose is a disaccharide made of glucose and fructose. It's commonly known as “table sugar” but it can be found naturally in fruits, vegetables, and nuts. However, it's also produced commercially from sugar cane and sugar beets through a refinement process. Here the most suitable answer is B.

Q137. Forces controlling the reactions are proportional to the product of the active masses (concentration) of chemicals. The above statement is of:

• A. Raoult‘s Law
• B. Le Chatlier‘s principle
• C. The law of conservation of energy
• D. The law of mass action✓

Explanation: The law of mass action states the rate of a chemical reaction is directly proportional to the product of the reactant concentration values. This law gives a formula for the equilibrium constant. Kc={C}^c {D}^d / {A}^a {B}^b

Q138. The sum of mole fractions of solute and solvent is always equal to:

• A. 0.1
• B. 10.0
• C. 1.0✓
• D. Zero

Explanation: The sum of mole fractions of solute and solvent is equal to one.

Q139. An Azeotropic mixture of two miscible liquids boils at a lower temperature than its components when:

• A. The system shows a negative deviation from Raoult‘s law.
• B. The system shows a positive deviation from Raoult‘s law✓
• C. The system perfectly obeys Raoult‘s law
• D. Both (A) and (B)

Explanation: An azeotrope is a binary mixture of two or more liquids that boils at a constant temperature at a given pressure and shows the same concentration and composition in both the liquid and vapor phases. Example: Benzene and Toluene form suitable azeotropes when mixed with water. When a solution shows a positive deviation from Roult’s law, the intermolecular forces present are weaker than those present in the ideal solution. The total vapor pressure of the solution is greater than the total vapor pressure of the ideal solution. Also, the vapor pressure of each component is greater than predicted by Roult’s law. Hence, the azeotropic mixture of two liquids boils at a lower temperature than either of them.

Q140. The ratio of output voltage V0 to the voltage difference Vin between the positive (+) input and negative (-) input of a pump is (where Vin=V+ – V – :

• A. Current gain
• B. Voltage gain✓
• C. Open-loop gain
• D. Close-loop gain

Explanation: The ratio between output and input voltage is voltage gain.

Q141. The resistance of light dependant resistance LDR:

• A. Increases with light
• B. Decreases with light✓
• C. Decreases with darkness
• D. None of the above

Explanation: Resistance of an LDR is inversely proportional to the intensity of light. In other words, with an increase in light intensity, the resistance of LDR decreases. When an LDR is kept in a dark place, its resistance is high, and, when the LDR is kept in the light its resistance will decrease.

Q142. The maximum kinetic energy of an electron ejected from a metal by a photon depends on:

• A. The photon‘s frequency only
• B. The metal work function✓
• C. The intensity of incident light
• D. None of the above

Explanation: The maximum kinetic energy of an electron ejected from a metal by a photon depends on the wavelength, frequency of the incident photon, and the work function of the metal.

Q143. A spring system executes simple harmonic motion. If a load is added to it then the time period of the spring-mass system will be:

• A. increased✓
• B. decreased
• C. the same
• D. halved

Explanation: The period of a spring-mass system is proportional to the square root of the mass and inversely proportional to the square root of the spring constant.

Q144. The diode that converts electrical energy into light energy is called:

• A. Solar cell
• B. Photodiode
• C. Vacuum diode
• D. Light emitting diode✓

Explanation: Light emitting diode converts electrical energy into light energy.

Q145. Which arrangement of the photons is in their decreasing energy?

• A. x rays > i.r. > u.v. > visible
• B. x rays > u.v. > visible > i.r.✓
• C. u.v. > x rays > visible> i.r.
• D. i.r. > visible > x rays> u.v.

Explanation: As we move down Energy, Frequency, and Momentum increase and Wavelength decrease.

Q146. The colors in the soap bubble are due to:

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

Explanation: The effect produced due to the superposition of two sets of light waves is called interference of light. The colors in the soap bubble are due to interference.

Q147. An object in a satellite orbiting around the earth is weightless because:

• A. g = 0
• B. No force acts on it✓
• C. Its motion is free fall
• D. It is far away from the earth

Explanation: The sense of weightlessness in orbiting satellites is because of the lack of any contact forces. The only force that acts upon objects in space is the force of gravity, which acts at a distance; but as there is no counter-force, we do not experience the sensation of weight over there. The counter or force-of-contact is missing because everything that floats in space does so due to the acceleration due to gravity being the same. Thus, both the object and the satellite have the same value of g, which is again equal to the centripetal acceleration of the satellite. These two neutralize each other, causing everything to appear weightless.

Q148. The expression for binding energy is:

• A. EB=fh
• B. EB=[(ZMP+ N Mn} – ZMA]C2✓
• C. EB= ZMPC2+ N Mn ZMA C2
• D. EB= ZMP+ NMn – MC2

Explanation: FACT

Q149. The half-life of the given sample is 44 years. The sample will reduce to 50% of the original value after:

• A. 22 years
• B. 88 years
• C. 11 years
• D. None of the above✓

Explanation: As the half-life of the sample is 44 years, it will take 44 years to reduce to 50% of its original value.

Q150. The time rate of change of magnetic flux has the same dimensions as that of:

• A. Current
• B. Resistance
• C. Magnetic induction
• D. Potential difference✓

Explanation: The explanation is given below.

Q151. The transverse nature of light is verified with the phenomenon of:

• A. Interference
• B. Polarization✓
• C. Diffraction
• D. Dispersion

Explanation: Transverse waves are waves whose vibration is perpendicular to the direction of propagation of waves. Light is a transverse wave. This means the vibrating electric field is perpendicular to the direction of propagation of light. Light can be either polarized or unpolarized. The light is polarized when the vibration of an electric field is in a specific direction. The light is unpolarized when the vibration of the electric field is not in a specific direction. Unpolarized light can be polarized. When an unpolarized light is passed through a polarizer, the light gets polarized. Polarizer has a plane of transmission in a specific direction. So, when the unpolarized light is passed through a polarizer, the transmitted light has the plane of the electric field in a specific direction. This makes the light polarized. Thus, the transverse nature of light was confirmed by the phenomenon of the polarization of light.

Q152. If a soap bubble is charged:

• A. Its size decreases
• B. Its size increases✓
• C. No change
• D. None of them

Explanation: On charging a soap bubble, there will be either a positive charge or a negative charge, and the charged particles will be distributed on the soap bubble which causes them to repel from each other due to electrostatic force. Due to its repulsive force between like charges the size will increase.

Q153. An electric current of 1 A is passing through a cross section of the coil in 1 second. How many electrons are involved in providing a current of 1A? The charge on 1 electron is 1.602x10 – 19 C.

• A. 3.21 × 10^18
• B. 2.2 × 10^16
• C. 1.602 × 10^19
• D. 6.42 × 10^18✓

Explanation: As we know, I = ne 1 A = n x 1.6 x 10^-19C n = 1 / 1.6 x 10^-19 n = 6.25 x 10^18

Q154. The uncertainty recorded in the radius of a sphere is 1.6%. The uncertainty in the area of that sphere is:

• A. 4.8%
• B. 3.2%✓
• C. 1.6%
• D. 0.8%

Explanation: We should use a decimal form to solve, To convert a percentage to a decimal, divide by 100 As, 1.6/ 100 = 0.016 We know the area of a sphere, A = 4π r2 Putting the value, A = (4)(3.14)(0.016)2 A= (4)(3.14)(0.000256) A = (12.56)(0.000256) A = 0.00322 A= 3.2 * 10^-3 A = 3.2%

Q155. An ideal transformer steps up or steps down:

• A. Energy
• B. AC voltage✓
• C. DC voltage
• D. Power

Explanation: An ideal transformer steps up or steps down AC voltage using the principle of electromagnetic induction. A changing current in the primary coil induces an emf in the secondary coil.

Q156. Three equal resistors connected in parallel have equivalent resistance R/3. When they are connected in series then the equivalent resistance is:

• A. R/3
• B. R
• C. 2R
• D. 3R✓

Explanation: As the resistors are connected in series then the equivalent resistance is 3R.

Q157. Which one of the following is not a vector quantity?

• A. Electric field intensity
• B. Gravitational field intensity
• C. Magnetic induction
• D. Electromotive force✓

Explanation: The physical qualities which can be described by their magnitude and directions are called vector quantities. The physical quantities which can be described by their magnitude only are called scalar quantities. So, an electromotive force is a scalar quantity. Because work has only magnitude, not direction.

Q158. Lenz‘s law is a particular form of the law of conservation of:

• A. Charge
• B. Current
• C. Energy✓
• D. Magnetic field

Explanation: Lenz’s law is a particular form of the law of conservation of energy. According to the diagram below when the N-pole of a bar magnet is approaching the coil, the magnetic flux linking the coil increases and the end of the coil towards the bar magnet becomes N-pole. Now the two N-poles oppose each other. Due to this opposition, the mechanical energy is converted into electrical energy. Thus, Lenz’s law is consistent with the law of conservation of energy.

Q159. The number of significant figures in the measurement x = 10.00300 are:

• A. 7✓
• B. 8
• C. 5
• D. 3

Explanation: The number of accurately known digits and the first doubtful digit are called significant figures. So, there are 7 significant figures. Zero after decimal to the right is significant because it shows the least count of the measuring instrument.

Q160. Two equal, anti-parallel, and nonconcurrent forces are:

• A. Couple✓
• B. Couple arm
• C. Collinear forces
• D. Torque

Explanation: Two equal, anti-parallel, and nonconcurrent forces are called a couple. The couple produces only angular acceleration. It produces pure rotational motion.

Q161. The minimum number of forces that keep the body in equilibrium is:

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

Explanation: Consider a particle having just one line of force acting on it. This force results in the acceleration of the particle disturbing its equilibrium. Consider a particle having two lines of forces acting on it. The forces are in opposite directions but of equal magnitude. They cancel each other resulting in equilibrium.

Q162. A ball of mass 5 kg is dropped from a height of 78.4 m. The time taken by the ball to hit the ground is:

• A. 2s
• B. 4s✓
• C. 8s
• D. 16s

Explanation: Data: mass = 5kg Height= 78.4m Acceleration = a = g = 9.8 m/s2 U = 0 m/s , Time taken by the ball to hit the ground=? Solution: According to 2nd equation of motion: S = ut + ½ gt2 78.4 = 0*t + ½ *9.8*t2 78.4 = 0 + 4.9 * t2 78.4 = 4.9 * t2 78.4 / 4.9 = t2 16 = t2 Taking square root on both sides of equal 4 = t So, the time taken by the ball to hit the ground is 4s.

Q163. In electromagnetic waves, the electric and magnetic vectors are:

• A. Parallel✓
• B. Anti parallel
• C. Perpendicular
• D. None of the above

Explanation: The two components of the electromagnetic wave are the electric and magnetic fields. The electric field is formed due to the flow of voltage and the magnetic field from the flow of current. The electric and magnetic fields are parallel to each other.

Q164. The negative gradient of electric potential is also called:

• A. Potential energy
• B. Electric field intensity✓
• C. Electric potential difference
• D. Electron-volt

Explanation: E = - ∆V/d Where the negative sign indicates that Electric field intensity is along decreasing potential.

Q165. The centripetal force acting on a body rotating in a circle of radius ‗r‘ is ‗F‘. If the body moves in a circle of radius half of the initial value keeping other quantities constant, then the percentage change in the centripetal force is:

• A. 300%
• B. 100%✓
• C. 400%
• D. 200%

Explanation: The initial centripetal force is F=(mv^2)/r. The final centripetal force is F^'=(mv^2)/(r/2)=2F. The percentage change in the centripetal force is (F^'-F)/F ×100 =(2F-F)/F × 100=100%

Q166. Which one of the following properties of electromagnetic waves does not change in a vacuum?

• A. Speed✓
• B. Wavelength
• C. Frequency
• D. All of the above

Explanation: Electromagnetic waves travel at a constant speed of 3 × 10^8m/s. c = f λ Speed remains constant as it is medium-dependent.

Q167. MRI works on the principle of:

• A. Beats
• B. Interference
• C. Resonance✓
• D. Standing waves

Explanation: The MRI machine is a large, cylindrical (tube-shaped) machine that creates a strong magnetic field around the patient and sends pulses of radio waves from a scanner. Some MRI machines look like narrow tunnels, while others are more open. The strong magnetic field created by the MRI scanner causes the atoms in your body to align in the same direction. Radio waves are then sent from the MRI machine and move these atoms out of the original position. As the radio waves are turned off, the atoms return to their original position and send back radio signals. These signals are received by a computer and converted into an image of the part of the body being examined. This image appears on a viewing monitor. When the frequency of an externally applied periodic force on a body is equal to its natural frequency, the body readily begins to vibrate with an increased amplitude, this is resonance.

Q168. The waveform of sinusoidal voltage, its frequency and phase can be found by:

• A. CRO✓
• B. Diode
• C. Transistor
• D. Radio

Explanation: CRO is used to measure the waveform of sinusoidal voltage which is saw tooth voltage waveform.

Q169. When a neutral body is rubbed and it becomes positively charged, it must have:

• A. Lost electrons✓
• B. Lost protons
• C. Gained protons
• D. Gained electrons

Explanation: When a neutral body loses an electron, it becomes a positive ion due to an imbalance of the electron-proton ratio.i.e.has more protons than electrons. The size of the cation is smaller than the size of the original atom because usually there is a loss of shell during the loss of an electron.

Q170. When a charged particle enters a uniform magnetic field, there is a change in:

• A. Kinetic energy
• B. Magnitude of velocity
• C. Direction of velocity✓
• D. All of these

Explanation: Since the force on the charge is always normal to the velocity of the charge so, the field does not work on the particle and the magnitude of velocity remains the same. So, kinetic energy is the same, whereas velocity changes direction because the magnetic field causes charged particles to deflect.

Q171. If two forces P and Q are such that |P + Q| = |P — Q|, then the angle between P and Q is:

• A. 0 degree
• B. 30 degree
• C. 90 degree✓
• D. 180 degree

Explanation: If we solve the question by vectors, Magnitude of P+Q=magnitude of P-Q P^2+Q^2+2PQcosx=P^2+Q^2–2PQcosx where x is the angle between the two quantities Therefore, 4PQcosx=0 Cosx=0 Therefore x=90 degree

Q172. Two blocks of masses 1.0 kg and 3.0 kg placed in contact are acted upon by a force of 40 N. The acceleration of 1.0 kg mass will be:

• A. 40 ms^-2
• B. 10 ms^-2✓
• C. 30 ms^-2
• D. 50 ms^-2

Explanation: As the bodies are in contact, the acceleration of the 1kg mass will be the total acceleration because in that case, those 2 masses will act like one big mass. Acceleration will be: F=(m1+m2)a a=F/(m1+m2) =>a=40/(1+3) =>a=10m/s^2

Q173. A body in equilibrium must not have:

• A. Kinetic energy
• B. Velocity
• C. Momentum
• D. Acceleration✓

Explanation: A body at equilibrium must have an acceleration of 0m/s2.

Q174. Sound waves cannot be:

• A. Polarized✓
• B. Reflected
• C. Refracted
• D. Diffracted

Explanation: A polarized wave vibrates in a single plane in space. Since sound waves vibrate along their direction of propagation, they cannot be polarized.

Q175. The spring constant of a spring is k. If the spring is cut into two halves then the spring constant of one of the halves is:

• A. k + 2
• B. k/2
• C. 2k✓
• D. k

Explanation: Here hooks law is applied as follows: F = -kx. The proportional constant k is called the spring constant. It is a measure of the spring's stiffness. When a spring is stretched or compressed, so that its length changes by an amount x from its equilibrium length, then it exerts a force F = -kx in a direction towards its equilibrium position. As; When a spring is cut into two pieces force has to be applied to increase the length of each piece by the same amount. So the spring constant of each piece will be 2k. Other options are wrong because they don't follow Hooke's law. F=KL K=F/L K is inversely proportional to L. So when it is cut into two equal parts its length decreases to half & simultaneously spring constant increases to 2K. (HENCE PROOVED).

Q176. A force of 6 N acts horizontally on a stationary mass of 2 kg for 4 s. The kinetic energy in Joule is:

• A. 12
• B. 144✓
• C. 72
• D. 48

Explanation: Initial velocity=0 Applied force=6N Mass of body=2kg Time interval=4s To find the K.E of the body Concept: The question is completely based on newtons sec law of motion. As per this law force is defined as the rate of change of linear momentum. F=dP/dt Momentum is defined as the product of mass and velocity. P=m×v The formula of K.E is given by K E= 1/2mv^2 Calculation: Find velocity F=dP/dt F=m×dv/dt F=m(v-u)/4 6=2(v-0)/4 V=24/2 V= 12m/s K.E=1/2mv^2 K=1/2×2×(12)2 K.E= 144J

Q177. A person travels a distance x = 20t+2At2, where A is a constant. The acceleration of the person is:

• A. A/4ms^– 2
• B. 4/A ms^– 2
• C. 4ms^-2
• D. 4Ams^– 2✓

Explanation: X= 20t+2At2 Differentiating w.r.t "t", DX/ft=V=20+4At (v=velocity) Now again differentiating w.r.t "t" dv/dt=a=4A. (a=acceleration) acceleration=4A Hence the acceleration of the person is 4A.

Q178. In the nuclear reaction 11 Na24 12Mg24 + X, the particle X is;

• A. Electron✓
• B. Positron
• C. Proton
• D. Neutron

Explanation: A is the correct option.

Q179. The angular displacement made by the minute hand of a watch after 5.0 minutes is:

• A. 30 degree✓
• B. 120 degree
• C. 180 degree
• D. 360 degree

Explanation: It takes an hour (60 minutes)for the minute's hand to turn a full circle or achieve an angular rotation of 2πradian. Solution: There are 60/5=12 periods of five minutes In an hour. Meaning that five- a minute rotation accounts for 1/12 of 2π, the rotation of a minute's hand in an hour. 2π.1/12=π\6 rad so the minute's hand shall see an angular displacement of π\6 radians. π\6 rad=30 degrees.

Q180. The intensity of a wave is:

• A. Directly proportional to the amplitude
• B. Directly proportional to (amplitude)2✓
• C. Inversely proportional to amplitude
• D. Inversely proportional to (amplitude)2

Explanation: The intensity of a wave is proportional to the square of its amplitude (I∝A^2).

Q181. Conversion of alternating current into direct current is called:

• A. Rectification✓
• B. Amplification
• C. Oscillation
• D. Regeneration

Explanation: The conversion of alternating current into direct current is called rectification.

Q182. Which of the following pairs have the same units and dimensions?

• A. Resistance and resistivity
• B. Conductivity and resistivity
• C. Electromotive force and potential difference✓
• D. Resistivity and temperature coefficient of resistivity

Explanation: Electromotive force (EMF) is equal to the terminal potential difference when no current flows. EMF and terminal potential difference (V) are both measured in volts, however, they are not the same thing. EMF (ϵ) is the amount of energy (E) provided by the battery to each coulomb of charge (Q) passing through.

Q183. The activity of the radioactive material can be expressed in the units of:

• A. Curie
• B. Becquerel
• C. Tesla
• D. Both (A) and (B)✓

Explanation: A material's radioactivity is measured in becquerels (Bq, international unit) and curies (Ci, U.S. unit).

Q184. The work function of a metal is 6.63 eV. The threshold frequency of the metal is:

• A. 1.6 × 10^15 Hz✓
• B. 1.6 × 10^12 Hz
• C. 6.63 × 10^-34 Hz
• D. 1.6 × 10^-19 Hz

Explanation: w=hv W=work function h=planks const V=threshold frequency V=w/h = 6.6×1.6×10^-19/6.6×10^-34 =1.6×10^-19×10^34 =1.6X10^15Hz

Q185. The birds sitting on an overhead transmission line suffer no harmful effects because:

• A. Their bodies have high resistance
• B. Their feet are good insulators
• C. There is a negligible potential difference between their feet✓
• D. Wires are insulated

Explanation: A bird is not affected practically because both of its legs are at the same potential thus, current cannot flow through its body.

Q186. Which of the following are Ohmic materials?

• A. Semiconductors
• B. Tungsten filament
• C. Thermistor
• D. Metals✓

Explanation: The many substances for which Ohm's law holds are called ohmic. These include good conductors like copper and aluminum and some poor conductors under certain circumstances. Ohmic materials have a resistance R that is independent of voltage V and current I. All metals are ohmic conductors and all semiconductors are non-ohmic materials.

Q187. Optical fibers guides:

• A. Current
• B. Light✓
• C. Sound
• D. Voltage

Explanation: Optical fiber is the technology associated with data transmission using light pulses traveling with a long fiber which is usually made of plastic or glass.

Q188. A hunter aiming a bird in a tree should aim:

• A. A little above the bird✓
• B. A little below the bird
• C. Exactly at the bird
• D. Very high

Explanation: Due to gravity because any projectile weapon we use is going to be affected by gravity. Even a fast-moving bullet is still pulled down as it travels. So, a hunter should always aim a bird a little higher.

Q189. The velocity of the projectile at its maximum height is:

• A. Zero✓
• B. Minimum
• C. Maximum
• D. In between maximum and minimum

Explanation: In projectile motion, at the maximum point, the velocity of the projectile becomes zero.

Q190. Hook‘s law correlates the:

• A. Force and displacement
• B. Force and extension
• C. Force and compression
• D. Stress and strain✓

Explanation: Hooke's law states that the strain of the material is proportional to the applied stress within the elastic limit of that material. Stress/Strain = Constant

Q191. Two forces of magnitude 20 N and 10 N act at a point then which one of the following cannot be their possible sum?

• A. 30 N
• B. 10 N
• C. 35 N✓
• D. 15 N

Explanation: If we add 20+10 it becomes 30 If we subtract 20-10 it becomes 10 The number that lies between 10 and 30 is 15 So, 35 is not their possible sum.

Q192. When a force is applied to a body, several effects are possible. Which one of the following effects could not occur?

• A. The body speeds up
• B. The body rotates
• C. The body changes direction
• D. Mass of body decreases✓

Explanation: The intrinsic properties of the body such as color, density, and mass do not change with the application of force.

Q193. The shortest wavelength of radiation in Paschen series is:

• A. RH/9
• B. 9/RH✓
• C. 9 RH
• D. 9 + RH

Explanation: Paschen series is the series of lines in the spectrum of the hydrogen atom which correspond to transitions between the state with principal quantum number n = 3 and successive higher states.

Q194. The part of the electromagnetic spectrum in which Lyman series lies is:

• A. Visible region
• B. Infrared region
• C. Ultraviolet region✓
• D. X-rays

Explanation: The Lyman series is a hydrogen spectral series of transitions and resulting ultraviolet emission lines of the hydrogen atom as an electron goes from n ≥ 2 to n= 1, so the Lyman series has the highest energy. As we move from the Lyman series to the Pfund series, energy decreases. Lyman series lies in ultraviolet region.

Q195. The first law of thermodynamics has a statement which implies that:

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

Explanation: The first law of thermodynamics states that energy can neither be created nor destroyed but can be changed from one form to another. ∆Q = ∆U + W

Q196. The sinusoidal AC in a circuit is I = 50 sin (20 t). The peak value of the current is:

• A. 100 A
• B. 25 A
• C. 50 A✓
• D. 20 A

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

Q197. Current in the semiconductors is caused by the movement of:

• A. Protons
• B. Electrons only
• C. Holes only
• D. Both electrons and holes✓

Explanation: Current flow in a semiconductor arises from the motion of charge carriers in both the conduction and valence bands. The mobile charges in the conduction band are electrons and those in the valence band are holes.

Q198. Darwin observed and collected thousands of specimens of diverse:

• A. Fauna of South America
• B. Flora of South America
• C. Fauna and flora of South America✓
• D. Fauna and anti flora of North America

Explanation: Charles Darwin was born in Shrewsbury, in Western England, in 1809. He joined ’ the expedition on Beagle to the South American coastline. He observed and collected thousands of specimens of diverse fauna and flora of South America. He noticed that the fauna and flora of the different regions of the continent had a definite South American stamp, very distinct from the life forms of Europe. Furthermore, the South American fossils that Darwin found, though different from modem species, were distinctly South American in their resemblance to the living plants and animals of that continent.

Q199. Archaeopteryx possessed both _ as well as _ characters:

• A. Reptilian, amphibians
• B. Reptilian, Avain✓
• C. Fishes, Avain
• D. Mammalian, Avain

Explanation: Archaeopteryx (pronounced ar-kee-OP-ter-iks) is a genus of avian dinosaurs that lived during the Late Jurassic period, approximately 150 million years ago. It is one of the most important fossils ever discovered, as it provides a direct link between dinosaurs and birds.

Q200. The idea of inheritance of acquired characteristics was given by:

• A. Lamarck✓
• B. Darwin
• C. Aristotle
• D. Lyell

Explanation: Lamarck believed that organisms can change over time through the inheritance of acquired characteristics. Theories proposed by other scientists are mentioned under their name.