Etea Mdcat 2006 — Solved Past Paper with Answers

Q1. "Browned off " means:

• A. grilled properly
• B. bored
• C. discouraged✓
• D. cleaned

Explanation: "Browned of" means to be annoyed, irritated or dissatisfied. The closest word to this in option provided is discouraged which is the correct option.

Q2. "Blow great trumpet / hom" refers to:

• A. boast✓
• B. violent flow of winds
• C. celebrate enthusiastically
• D. eruption of war

Explanation: Blowing ones own trumpet refers to talking about your own achievements in a way to depict that you are too proud. Hence boast is the correct as it refers to being too proud and showing off your achievements.

Q3. Many ancient civilizations …………… on the banks of major rivers.

• A. dashed
• B. flourished
• C. sprawled✓
• D. succeeded

Explanation: Sprawl refers to spreading out over a large area. The ancient civilisations sprawled on the banks of major rivers.

Q4. Which one is an auxiliary?

• A. With
• B. On
• C. Do✓
• D. For

Explanation: The only auxiliary verb here is do.

Q5. "Homicide"

• A. is a poison
• B. means killing members of one's species
• C. means "munder"✓
• D. means "the murderer of one's own family

Explanation: Homicide means murder.

Q6. She dresses with great—--------------- and that is how she impresses people.

• A. pride
• B. outrageousness
• C. ostentation✓
• D. panache

Explanation: Ostentation is characterized by pretentious or showy display; designed to impress. Hence option C is correct.

Q7. It is very difficult to relax while working with their new boss because he is a hard

• A. worker
• B. hearted
• C. taskmaster✓
• D. nut crack

Explanation: Taskmaster is a person who imposes a harsh or onerous workload on someone.So this word is most suitable to be used in this sentence.

Q8. AUTOCRACY is the govemment of

• A. One person with absolute power✓
• B. lawyers fraternity
• C. Elected representatives of the masses
• D. intelligentsia

Explanation: Autocracy a system of government by one person with absolute power. Hence option A is correct.

Q9. 'The Bottom line is that we cannot ignore the cultural aspect in education'. The underlined expression means:

• A. most important thing✓
• B. the last line in a essay
• C. conclusion
• D. Trend

Explanation: Bottom line is a noun meaning the fundamental and most important factor. Hence, option A is correct.

Q10. His fondness _ makes his writings difficult to understand because most readers don't know the knewly invented words.

• A. archaic words
• B. sking
• C. advanced words
• D. Neologism✓

Explanation: Neologism means a newly coined word or expression. Hence D is most appropriate answer.

Q11. The building with numerous arhes looked _ in the midnight.

• A. Brightly
• B. Splendidly
• C. mysteriously
• D. magnificent✓

Explanation: (Option A , B& C) Brightly, Splendidly and mysteriously are adverbs where as here the word being used is such that it would describe the building (and how it looks in the moonlight). Hence, the appropriate word should be an adjective i.e. magnificent.

Q12. The air we —------------ today has many harmful elements in it.

• A. Breathe✓
• B. are breathing
• C. breath
• D. have breathed

Explanation: Breathe is a verb we use for the process of inhaling and exhaling. Breath is a noun that refers to a full cycle of breathing. Breathe is a verb to be used here.

Q13. In time of war, government do things which are E.pedient. The underlined word means

• A. Endorsed by war council
• B. Concominant✓
• C. Need of hour
• D. Usefull but not necessarily right

Explanation: Expedient means an action that is convenient and useful but may be morally inappropriate. Concomitant means something associated and accompanied by something else. For example, memory loss is a natural concomitant of old age.

Q14. The man sitting next to me on the plane was nervous because he _ before.

• A. had not flown✓
• B. did not fly
• C. has not flown
• D. has not been flown

Explanation: The use of “was” in the first part of the sentence and the word “before” at the end suggest it to be a past sentence. So we can rule out the second last option as it uses present perfect tense. The last option is incorrect itself as “been” is only used with perfect continuous tense. It will be wrong to use “ has been flown”, the correct structure for this will be, “has been flying”. Simple past tense is not a very suitable option as well. The correct use of tense here will be the past perfect tense. Past perfect tense states an action that happened ( had never flown ) before another action took place ( his first flight ). So this implies that he had not flown before his first flight. Now the complete sentence will be as follows: “The man sitting next to me on the plane was nervous because he had not flown before”.

Q15. The role of bacterial population in the large intestine of man is to;

• A. break down of cellulose
• B. synthesize some vitamins✓
• C. produce intestinal juice
• D. absorb water and mineral salts

Explanation: The large intestine is home to trillions of bacteria which are majorly involved in the production of vitamins (vit B1, B9, B7, B2, b5, vitamin K) and controlling growth of harmful bacteria.

Q16. The social organization of howling monkeys was studied by:

• A. Allen
• B. Thorpe
• C. schjeldeup-ebbc
• D. Carpenter✓

Explanation: A field study of the behaviour and social relations of black howling monkeys (Alouatta caraya) was done by Carpenter.

Q17. A cell fails to detoxity the waste substances produced in it because it does not possess enough:

• A. lysosomes
• B. ribosome
• C. rough endoplasmic reticulum
• D. smooth endoplasmic reticulum✓

Explanation: The cell organelle responsible for the detoxification of waste substances is the smooth endoplasmic reticulum. The main functions of the smooth ER include synthesis of lipids/steroid hormones, detoxification of harmful metabolic byproducts and the storage and metabolism of calcium ions within the cell.

Q18. Vertebrate with one occipital condoyle is:

• A. pigeon✓
• B. frog
• C. monkey
• D. rabbit

Explanation: Occipital condyle is a rounded knob-like structure that is present at the base of the skull which articulates with the first vertebra. It helps animals to move their heads. Mammals and amphibians have two occipital condyles, reptiles and birds have only one. As monkeys and rabbits are mammas and frog is an amphibian, they all have 2 Ocs whereas a pigeon is a bird so it has one OC which is why it is the correct answer.

Q19. The flower of family gramineae (poaceae contains two scales below-ovary, which are called:

• A. glumes
• B. lemma & palea
• C. lodicules✓
• D. rochilla

Explanation: Gramineae/Poaceae is a large family of monocotyedenous plants commonly known as grasses. Lodicules are scales present below the ovaries of grass flower. A glume is a bract below a spikelet in the inflorescence of grasses or the flowers of sedges. There are two other types of bracts in the spikelets of grasses: the lemma and palea

Q20. The opening between right atrium and right ventricle is guarded by

• A. semi lunar valve
• B. tricuspid valve✓
• C. bicuspid valve
• D. semicircular valve

Explanation: The opening between the right atrium and right ventricle is guarded by the tricuspid valve.

Q21. The total of all the allele in a population is called:

• A. genetic drift
• B. genotype
• C. gene pool✓
• D. gene mutation

Explanation: The total of all the alleles in a population is known as the gene pool of that population.

Q22. Which one of the following in glycolysis is a hydrogen carrier?

• A. ADI
• B. PGAL
• C. DPGA
• D. NAD✓

Explanation: Option D is correct as NAD is the hydrogen carrier in glycolysis that assists in oxidation reactions and gets reduced in the process to form NADH.

Q23. The cells that play vital role in the differentiation of various body parts are called:

• A. Ectodermal cells
• B. Mesodermal cells✓
• C. Endodermal cells
• D. All of the above

Explanation: The mesoderm is a germ layer that arises during gastrulation and is present between the endoderm and the ectoderm. The mesoderm is responsible for the formation of several critical structures and organs within the developing embryo including the skeletal system, the muscular system, the excretory system, the circulatory system, the lymphatic system, and the reproductive system so various body parts arise from the mesodermal cells.

Q24. Alternation of generations in plants is regarded a mechanism for:

• A. Achieving haploidy
• B. Promoting survival✓
• C. Producing diploidy
• D. Having no significance

Explanation: Plants alternate between the diploid sporophyte and haploid gametophyte, and between asexual and sexual reproduction. Which is known as alternation of generations. This ability of the plants helps them to adapt to different environments. The alternation of generations allows for both the dynamic and volatile act of sexual reproduction and the steady and consistent act of asexual reproduction. Plants are sessile. They don't move. By employing an alternation of generations they have better chances of increasing their number and hence are important for their survival.

Q25. The individual with hare-lip shows which of the following condition?

• A. Cleft palate✓
• B. Polydactyly
• C. Hard-palate
• D. Microcephaly

Explanation: The individual with Hare Lip shows a cleft palate which is an opening in the upper lip when developing facial structures in an unborn baby don’t close up completely.

Q26. Receptors sensitive to smell are

• A. Mechanical
• B. chemical✓
• C. photoreceptors
• D. georeceptors

Explanation: Receptors sensitive to smell are chemoreceptors called olfactory receptors.

Q27. Which hormone prepares the body for situations of stress and emergency?

• A. Adrenaline✓
• B. Non adrenaline
• C. Thyroxin
• D. Insulin

Explanation: Adrenaline triggers the body's fight-or-flight response. This reaction causes air passages to dilate to provide the muscles with the oxygen they need to either fight danger or flee. Adrenaline also triggers the blood vessels to contract to re-direct blood toward major muscle groups, including the heart and lungs.

Q28. Which of the following type of cytochromes is common in photosynthesis and respiration?

• A. Cyt “O”
• B. Cyt “a3”
• C. Cyt “b”✓
• D. Cyt “c”

Explanation: A membrane-bound cytochrome f-b complex participates in both respiratory and photosynthetic elevtron transport.

Q29. Anticodon of AUG will be:

• A. TAC
• B. UAC✓
• C. AUG
• D. CCA

Explanation: Anticodons are as follow: A = U( in case of RNA) A=T ( in case of DNA) C=G( same in both cases)

Q30. Which of these is a freshwater sponge?

• A. Sycon
• B. Leucosolenia
• C. Spongilla✓
• D. Euplectella

Explanation: Spongilla is a genus of freshwater sponges, not an example of a sponge.

Q31. In earthworms many Enzymes are present

• A. Typhlosole
• B. Intestinal caeca
• C. Esophagus
• D. Pharyngos mass✓

Explanation: Pharynx: It’s a thick-walled, pear-shaped chamber, which extends to the 4th segment. It is differentiated from the buccal chamber by a dorsal groove where the brain of an earthworm is present. The dorsal part of the pharynx has a pharyngeal bulb, which is made up of muscle fiber, connective tissues, blood vessels, and salivary glands. Salivary glands are unicellular and known as chromophils. Chromophil cells secrete saliva which contains proteolytic enzymes protease which converts protein to amino acids. Mucin is the other enzyme present, which makes the food soft.

Q32. Fibrinogen is a protein produced by

• A. Gallbladder
• B. Liver✓
• C. Kidneys
• D. Lungs

Explanation: Fibrinogen is a protein produced by the liver. This protein helps stop bleeding by helping blood clots to form.

Q33. All the flowers come at the same level due to equal size of their pedicels in

• A. corymbs
• B. umbel✓
• C. catkin
• D. panicle

Explanation: The pedicel is a stalk or stem that supports a single flower. It connects the single flower to the inflorescence. It is usually seen in pedicellate flowers (e.g., Roses). The flowers without pedicels are called sessile flowers (e.g., Sunflower).In an umbel, each of the pedicels initiates from about the same point at the tip of the peduncle, giving the appearance of an umbrella-like shape.

Q34. A living tissue which in addition to its regular fianction also provides support to plants is:

• A. Xylem
• B. Collenchyma✓
• C. Sclerenchyma
• D. Parenchyma

Explanation: Collenchyma is living tissue that provides support to the plant as it has extra cellulose deposited in its cell wall the cell wall is non-lignified.

Q35. The control centre of speech is:

• A. Medulla oblongata
• B. Diencephalom
• C. Cerebrum✓
• D. Cerebellum

Explanation: The largest part of the brain, the cerebrum initiates and coordinates movement and regulates temperature. Other areas of the cerebrum enable speech, judgment, thinking and reasoning, problem-solving, emotions, and learning.

Q36. Filter feeders extract food particles from:

• A. Water✓
• B. Soil
• C. Air
• D. Blood

Explanation: Filter feeders primarily extract food particles from water. They possess specialized structures or mechanisms to filter out and capture small organisms or organic particles suspended in the water column. These organisms include various types of plankton, algae, or other microscopic organisms present in aquatic environments. Examples of filter feeders in water include baleen whales, certain species of fish, and many types of invertebrates like clams, mussels, and krill. Filter feeders do not typically extract food particles from soil or air. Soil contains organic matter and nutrients, but filter feeders are not adapted to extract food from this medium. Instead, organisms that feed on soil, such as earthworms, nematodes, and various microorganisms, employ different mechanisms like ingestion and decomposition to derive nutrients from organic matter in the soil. Similarly, while some organisms extract small particles from the air, they are not generally referred to as filter feeders. Airborne particles are usually captured through mechanisms such as trapping or sticking to surfaces like hairs or mucus membranes found in the respiratory systems of animals or the surface of plants. These particles may include pollen, dust, or spores. Examples of organisms that capture particles from the air include certain insects, like mosquitos, which feed on pollen or nectar, and some birds that catch flying insects in flight. Finally, the option of blood is not applicable to filter feeders. Filter feeders are not specialized to extract food particles directly from blood. Blood is a fluid found within the circulatory system of animals and is primarily used to transport nutrients, oxygen, and waste products throughout the body. Filter feeders do not target blood as a food source, and their feeding mechanisms are not adapted to extract nutrients from it. In summary, filter feeders primarily extract food particles from water, while soil, air, and blood are not typical sources of nutrition for these organisms.

Q37. On the basis of which of the following ratio we can prove law of independence assortment?

• A. 9:3:3:1✓
• B. 9:3:4
• C. 1:2:1
• D. 2:11

Explanation: The law of independent assortment is related to the inheritance of 2 unlinked traits whose alleles assort independently of each other at the time of meiosis, giving rise to genetic variation. To prove this a dihybrid cross, of two heterozygotes, is carried out for two distinct traits. By drawing a punnet square as shown we can find out the ratio. The ratios given in B, C, and D do not fit this scenario.

Q38. Photorespiration accurs when:

• A. Stomata are opened
• B. Day is humid
• C. Concentration of CO2 inside the leaf is high
• D. Concentration of O2 inside leaf is high✓

Explanation: Respiratory activity which occurs in plants during the daytime is called photorespiration. Factors that cause photorespiration are hot and dry climates as well as closed stomata. Due to the hot and dry climate stomata close to prevent water loss. Due to closed stomata level of CO2 falls as it is consumed and O2 rises as it isn't let out into the atmosphere, increasing O2 concentration and promoting photorespiration.

Q39. In geneaction the gene that mark the expression of another gene is formed as

• A. Hypostatic
• B. Epistatic✓
• C. Hemistatic
• D. Neostatic

Explanation: Epistatic is the gene that masks the expression of an allele at a separate locus.

Q40. Green house effect is NOT produced by the abundance of the gas called

• A. Methane
• B. CO2
• C. Nitrous oxide
• D. Sulphur dioxide✓

Explanation: The greenhouse effect is how heat is trapped close to Earth's surface by “greenhouse gases.” These heat-trapping gases can be thought of as a blanket wrapped around Earth, keeping the planet toastier than it would be without them. Greenhouse gases include CO2, methane, nitrous oxide, and water vapor which are options A, B & C respectively. Option D is SO2 which is an atmospheric pollutant produced by volcanic eruptions and combustion engines. It is mainly responsible for acid rain, not the greenhouse effect hence is the wrong option.

Q41. The step in glycolysis in which energy transfer is not involved is:

• A. Glucose phosphate → fructose diphosphate
• B. Fructose diphosphate → DAP✓
• C. PGAL→ PGAP
• D. PGAP→ PGA

Explanation: Energy transfer here occurs by the transfer of phosphate group from one compound to another.

Q42. Which one among the following is in fact a fruit, but is available in a vegetable shop?

• A. Capsicum annum✓
• B. Solanum Tuberosum
• C. Medicago denticulata
• D. Bauhinia variegata

Explanation: A Capsicum annum is Chilli pepper (fruit). B Solanum Tuberosum is Potato (Vegetable). C Medicago denticulata is Burr medic (A plant). D Bauhinia variegata is an orchid tree (flowering plant). So correct answer is A.

Q43. How much energy will be fixed by the primary carnivores?

• A. 2317 Kcal
• B. 232 kcal
• C. 1564 kcal
• D. None of above.✓

Explanation: 80-90% of energy is lost by each organism as we move up trophic levels. However, we are not aware of how many herbivores or primary carnivores so we cannot estimate how much energy will be fixed in primary carnivores.

Q44. The word SEISMOLOGY stands for:

• A. An instrument for detecting earthquakes
• B. Study of sea creatures
• C. A branch of Astrology
• D. A scientific study of earthquakes✓

Explanation: Seismology is the study of earthquakes.

Q45. Blood cells are produced by:

• A. Liver
• B. Spleen
• C. Bone marrow✓
• D. Heart

Explanation: Blood cells are produced in (red) bone marrow from stem cells. Red blood cells are destroyed in the liver or spleen (options A & B).

Q46. Organs of locomotion in earth worm are:

• A. Papillae
• B. Setae✓
• C. Pseudopodia
• D. Cuticle

Explanation: Organs of locomotion in earth worms are setae. Setae are present on parapodia on the body wall or embedded in sacs.

Q47. Gonorrhea is a sex disease caused by:

• A. Bacteria✓
• B. Virus
• C. Parasite
• D. None of above

Explanation: Gonorrhea is caused by a gram-positive bacteria called Neisseria gonorrhoeae. Options B and C are viruses and parasites and hence are wrong as bacteria is the correct answer here.

Q48. Which of the following is an inactive enzyme without its cofactor?

• A. Coenzyme
• B. Apoenzyme✓
• C. Holoenzyme
• D. Denatured enzyme

Explanation: Apoenzyme is an inactive enzyme without its cofactor.

Q49. Laiba is trying to determine the percentage of protein in bears because she is a

• A. Biochemist✓
• B. Microbiologist
• C. Physiologist
• D. Mycologist

Explanation: Laiba is a biochemist who is trying to determine the percentage of protein, a biomolecule, in beans. Moreover, a biochemist deals with the branch of science concerning the chemical processes taking place within an organism.

Q50. Which of these are carriers of genetic information?

• A. rRNA
• B. mRNA
• C. DNA✓
• D. Nucleotides

Explanation: A DNA molecule is a double helix carrying the genetic information of an organism. It encodes all the genetic instructions involved in the growth and development of an individual. Genes, which are fragments of DNA, are basic hereditary units.

Q51. Genome of which of the following consists of a single molecule of DNA?

• A. HAV
• B. HBV✓
• C. HCV
• D. HIV

Explanation: HBV has a single circular double-stranded DNA genome.

Q52. Lithotripsy is a technique to:

• A. Remove kidney stones without surgery✓
• B. Remove kidney stones with surgery
• C. Treat kidney with medicines
• D. Remove appendix

Explanation: Lithotripsy involves the treatment of stones in the kidneys or ureters by using high-energy shock waves, breaking the stones which can then be passed by urine. It is a non-invasive, nonsurgical method and is highly effective for kidney stones that are very large to be passed in the urine.

Q53. Which one of the following plants feeds on water mites?

• A. Nepenthes
• B. Utricularia
• C. Dionea
• D. Sundew✓

Explanation: Drosera or sundew is a carnivorous plant found in moist, acidic, and nutrient-deficient soils. Such places are home to mosquitos and other insects and drosera feed on these to fulfill their nitrogen needs.

Q54. Goiter is caused by a deficiency of

• A. Sodium in water
• B. Calcium in water
• C. lodine in water✓
• D. Sugar in water

Explanation: Goitre is characterized by an enlarged thyroid gland which appears as a lump or swelling in front of the neck. It is caused due to the deficiency of Iodine in the diet. Iodine is naturally present in drinking water. Other sources of iodine include fish, shrimp, seaweed, iodized salt, etc.

Q55. Which one of the following is found in plant cells only?

• A. Peroxisomes
• B. Lysosomes
• C. Glyoxisomes✓
• D. Ribosomes

Explanation: Glyoxisomes are specialized organelles found only in plants. These contain enzymes for the glyoxylate cycle, through which fats are converted into carbohydrates (gluconeogenesis). These are found in germinating seeds and are responsible for fat metabolism.

Q56. Neuron that carries messages from sense organ to the central nervous system is:

• A. Afferent neuron✓
• B. Efferent neuron
• C. Associative neuron
• D. Interneuron

Explanation: Afferent neurons, also known as sensory neurons are responsible for establishing a link between the sensory organ and the central nervous system by conducting impulses toward the brain and spinal cord.

Q57. Corpuscular animals are active during:

• A. Night
• B. Day
• C. Twilight✓
• D. Spring

Explanation: The animals which are active during the twilight period are called crepuscular animals.

Q58. Red tides in oceans are produced by:

• A. Diatoms
• B. Dinoflagellates✓
• C. Water molds
• D. Myxomycota

Explanation: The rapid increase in the population of red dinoflagellate (a type of algae), causes the sea to appear red, which is responsible for the occurrence of red tides.

Q59. The cartilage present in trachea is:

• A. Fibrous
• B. Hyaline✓
• C. Elastic
• D. Neurotic

Explanation: Hyaline cartilage is found at the ends of long bones and in the nose at the larynx and trachea.

Q60. Rabbits, pabulus, rats grasshoppers and grasses constitute a

• A. Habitat
• B. Biome
• C. Community✓
• D. Population

Explanation: A community is a group or association of populations of two or more different species occupying the same geographical area at the same time.

Q61. Size of the flower of chrysanthemum may be enlarged by removing

• A. All leaves
• B. A few leaves
• C. All branches except one
• D. All floral bud except one✓

Explanation: To achieve the largest size of chrysanthemum flowers, it is made sure there is only one terminal bud at the top of each stem. If there are several buds, all other buds growing alongside the big bud at the very top are carefully removed. This will ensure that the largest flower will develop at the end of each stem that has been trained.

Q62. A peptide bond is formed between:

• A. An aldehyde group and an amino group
• B. An aldehyde group and an ester group
• C. An aldehyde group and a carboxyl group
• D. A carboxyl group and an amino group✓

Explanation: A peptide bond is formed between a carboxyl group and an amino group.

Q63. The opening and closing of stomata are controlled by which of the following factor(s)?

• A. Sugar✓
• B. pH
• C. Potassium
• D. All of the above

Explanation: Starch-sugar interconversion hypothesis of stomata opening and closing (a) During the daytime: According to this theory, the CO2 released in respiration is utilized in the process of photosynthesis, which makes the medium of the guard cell alkaline. Due to this high pH, the starch produced at night is converted into sugar in the presence of the enzyme phosphorylase. Sugar is soluble in water and consequently increases the osmotic pressure of the guard cells. Therefore, the cells become turgid. In this state, the thin outer wall of the guard cell stretches outward and opens the stomata. (b) During the night: During the night, the CO2 produced in respiration is not utilized and diffuses into the cytoplasm of guard cells. It makes the medium of the guard cells acidic (low pH). At this low pH, the sugar made during the daytime is also converted into starch. Starch, being insoluble in water, reduces the osmotic pressure of the guard cell. Consequently, water moves from guard cells to the attached subsidiary cells. It makes the guard cells flaccid and, therefore, the stomata close.

Q64. At constant temperature, as the pressure of a gaseous mixture in equilibrium increases, the equilibrium constant

• A. remains constant✓
• B. increase
• C. decrease
• D. varies

Explanation: Changing the pressure of a gaseous mixture has no effect on the equilibrium constant, as the equilibrium constant only changes if there is a change in temperature. As it is mentioned in the question that the temperature is constant, the value of equilibrium will remain the same.

Q65. Na+ is isoelectronic with:

• A. Mg
• B. He
• C. Fe
• D. Ne✓

Explanation: Isoelectronic means that two species have the same number of electrons. Na+ has 10 electrons as it has lost one electron to become an ion. Mg has 12, Fe has 26, He has 2, and Ne has 10. So Ne and Na+ both have 10 electrons, which means they are isoelectronic.

Q66. Fruit juices are often sold in aluminum cans. What is the most important reason?

• A. Aluminium can be recycled
• B. Aluminium is light
• C. Aluminium is cheaper
• D. Aluminium is resistant to corrosion✓

Explanation: It is because aluminium is resistant to corrosion by organic acids.

Q67. Consider the following equation: N2+O2 _ 2NO. The partial pressure (ln atm) of N2 under normal atmospheric pressure

• A. 0.05
• B. 0.25✓
• C. 0.35
• D. 0.45

Explanation: Partial pressure = moles of substance/total moles * total pressure =moles of N2/total moles * total pressure =1/4 * 1 atm = 0.25

Q68. Compounds that tend to donate electron pairs are known as Lewis bases or nucleophiles. Which one of the following is not a Lewis base?

• A. CH3-NH2
• B. PH3
• C. AICI3✓
• D. H2O

Explanation: A Lewis base is a species with the ability to donate an electron pair, so they must have a lone pair of electrons. Option C is correct as AlCl3 is a Lewis acid due to the valence shell of Aluminium being open, i.e., there is an incomplete octet.

Q69. Which of the following reagents can be used to identify Ni+2 ions in solution?

• A. Ethylenediamine
• B. potassium ferrocyanide
• C. dimethylglyoxime✓
• D. potassium permanganate

Explanation: To test for Ni+2 ions, dimethyl glyoxime is used. When adding dimethyl glyoxime to a solution along with ammonium hydroxide, a bright red precipitate is formed, which indicates the presence of Ni2+ ions in the solution. This is a factual recall.

Q70. Which one of the following molecules does not contain nitrogen?

• A. Aniline
• B. Pyridine
• C. Hydrazine
• D. Naphthalene✓

Explanation: Option D is correct as it is an aromatic hydrocarbon containing two fused benzene rings with the formula C10H8 hence it does not contain nitrogen.

Q71. What product is obtained when methyl magnesium chloride reacts with ammonia?

• A. Methane✓
• B. Methylamine
• C. Ethylamine
• D. Methyl chloride

Explanation: Methane is the correct option, as Grignard reagent (CH3MgCl) is basic in nature, so it will accept H+ from NH3 forming CH4 and H2NMgCl.

Q72. Which of the following cannot be displaced from their salt solution by cell?

• A. Ag
• B. AU
• C. Al
• D. Zn✓

Explanation: More reactive metals can displace less reactive metals from their salt soution. Zinc cannot be displaced from its salt solution by a cell as it is more reactive than copper, whereas silver, gold, and platinum can be displaced from their salt solution as they are less reactive than copper.

Q73. For the atomic numbers given below, which pair of elements will have the same chemical properties?

• A. 13,22
• B. 3,11✓
• C. 4,24
• D. 2,4

Explanation: Option B is correct as the elements with atomic numbers 3 and 11 are Lithium and sodium, respectively which are both in the same group, hence they have the same chemical properties. Elements in the same group have the same number of valence electrons and thus have similar chemical properties.

Q74. 74g of calcium hydroxide will yield OH ions:

• A. 178
• B. 34g✓
• C. 51g
• D. 40g

Explanation: 74g of Ca(OH)2 = 1 mol of Ca(OH)2, as the molecular mass of Ca(OH)2 is 74. Ca2+ + 2OH- ------> Ca(OH)2 As shown by the equation, 1 mol of Ca(OH)2 yields 2 moles of OH- So from 74 g of Ca(OH)2, 17 x 2 = 34 g of OH will be produced.

Q75. Which of the following pairs has the same electronic structure?

• A. Ar & C✓
• B. Ca & Ar
• C. Mg and Na
• D. Ag & Sn

Explanation: Argon has 18 electrons. The chloride ion also has 18 electrons.

Q76. Which one of the Grignard reactions below could give rise to CH3CH3CH(OH)CH2CH3?

• A. Propane and methyl Grignard
• B. Methyl ethyl ketone and methyl
• C. Propanaldehyde and ethyl Grignard✓
• D. None of these

Explanation: The addition of Grignard reagent to aldehydes leads to the production of secondary alcohol, and the addition of ketone leads to the production of tertiary alcohol. As the alcohol produced in the question is secondary, the correct option would be the one with the reaction of aldehyde with grignard reagent, hence option C. Option A is incorrect as alkanes do not directly react with grignard to form alcohol; grignard reacts with alcohol to produce alkane. Option B is incorrect, as with ketone, a tertiary alcohol is formed, which is not the case in the question.

Q77. In glass manufacturing process, annealing is done for the prevention of

• A. Air bubbles✓
• B. impurities
• C. Strain
• D. Shining

Explanation: Annealing is done to prevent air bubbles. The melting temperature is increased so that the viscosity decreases, which in turn facilitates bubble removal.

Q78. If 28.0g nitrogen gas is reacted with 8.0g of hydrogen gas to form ammonia, the limiting reactant among the two will be:

• A. N2✓
• B. H2
• C. both (a) & (b)
• D. No of these

Explanation: The limiting reagent is the reactant that is completely used up in a reaction and thus determines when the reaction stops.

Q79. The unit f Kc or the system N2O4 g ----------- 2NO2 g

• A. dimension (i.e., with no unit)
• B. mole dm3
• C. mole dm-3✓
• D. mole2 dm3

Explanation: Option c is the correct option.

Q80. What is the trade name of tetralluoroethylene polymer?

• A. Polystyrene
• B. Bakelite
• C. Nylon
• D. teflon✓

Explanation: PTFE (Polytetrafluoroethylene) is also known as Teflon.

Q81. In a closed room of 1000m 'a perfume boiler is opened up. The room develops a smell. This is due to which property of gases?

• A. diffusion✓
• B. viscosity
• C. density
• D. none of the above

Explanation: Diffusion is the net movement of gases from a region of higher concentration to a region of lower concentration. Gases spread due to diffusion down the diffusion gradient.

Q82. The emf of a galvonic cell can be calculated from:

• A. The size of the electrode
• B. The pH of the solution
• C. The amount of metal in the anode
• D. The values of the half cell✓

Explanation: For a galvanic cell, emf can be calculated by standard reduction potentials for two half cells. Emf is independent of pH except for the reactions involving H+ or OH- ions. Emf is independent of shape and size of electrodes,distance between electrodes and the amount of electrolyte.

Q83. Which of the following is NOT correct in case of carboxylic acids?

• A. they are polar molecules
• B. they form H-bonds
• C. they are stronger than mineral acids✓
• D. they have higher boiling points than their corresponding alcohols

Explanation: Mineral acids are stronger acids than carboxylic acids because mineral acids are completely ionized, whereas carboxylic acids are partially ionized.

Q84. The total energy of a H-atom in its ground state is:

• A. -Ve✓
• B. +Ve
• C. Zero
• D. None

Explanation: In the hydrogen atom, the force we are primarily referring to is the attractive force acting between the nucleus and the electron and this is obviously electrical in nature We know for a fact from Coloumb’s Law, that the electrostatic force between two like charges is positive in sign, while that between two unlike charges is negative in sign; Hence negative force means that it is attractive in nature; Therefore, this negative force vector and its multiplied value with the displacement vector (which is always considered positive since the nucleus is the origin) gives the value of the electron’s energy in the negative sign hence option A is correct.

Q85. When ethanol is treated with fehling's solution. It gives a precipitate of:

• A. Cu
• B. CuO
• C. Cu2O✓
• D. Cu2 O + Cu2 O3

Explanation: Fehling solution is reduced by aldehydes and a red precipitate of Cu2O is obtained.

Q86. The Cl Atom attached to benzene ring is:

• A. m-directing
• B. o-directing
• C. o -& p -directing & deactivating✓
• D. o -& p -directing & activating

Explanation: Chlorine has a lone pair, so it can donate electrons to the benzene ring. Chlorine has high electronegativity, so it can withdraw the electron density from the ring. Chlorine increases electron density at the ortho and Para positions and decreases at the meta position, so it is ortho-para-directing.

Q87. Acetic anhydride is obtained from acetyl chloride in the reaction with:

• A. P2O5
• B. H2SO4
• C. +CH3 COONa✓
• D. CH3COOH

Explanation: Acetyl chloride reacts with sodium acetate to give acetic anhydride.

Q88. Which form of matter possesses a higher magnitude of internal energy?

• A. Gaseous matter
• B. Solid matter
• C. Liquid matter
• D. all have same magnitude✓

Explanation: Internal energy is defined as the sum of kinetic and potential energies associated with the random motion of atoms in a substance, and consequently, it depends on temperature and the state of matter. As can be seen from the image, it can be deduced that Temperature effects the kinetic energy of atoms, while change of state effects their potential energy. Hence, as substance changes from Solid to liquid and from liquid to gas, its particles move apart, potential energy increases, and internal energy increases.

Q89. A bottle of dry NH3 and a bottle of dry HCI connected through a long tube are opened simultaneously of both ends. The white NHCl ring formed will be

• A. at the center of the tube
• B. near the NH3 bottle
• C. near the HCI bottle✓
• D. throughout the length of the same tube

Explanation: When connecting the two bottles, the two gases will diffuse into each other. The rate of diffusion is inversely proportional to the square root of molecular mass. Considering the molecular masses (NH3 = 17 and HCl = 36.5), HCl, being the heavier gas, will diffuse slower (cover less distance), while the lighter gas NH3 will diffuse faster (cover more distance). So the white ring of NH4Cl (formed by the reaction of two gases) will be closer to the HCl bottle. This case is explained in option C. A, B, and D do not fit the relation between rate of diffusion and Molecular mass.

Q90. When β -particle is emitted from lead(82Pb212), the mass number and charge number of bismuth formed are

• A. 83Bi212✓
• B. 81Bi210
• C. 85Bi210
• D. None of these

Explanation: The reaction that occurs when a β- particle is emitted is as follows: Hence, on emission of a β- particle from the nucleus, the mass number remains the same, while the proton number increases by one. and (In the given question statement, the proton number is. Considering the proton number of lead, option A is the most suitable, as by increasing the proton number by 1, we get 83. Option B and C proton numbers are wrong.

Q91. Acetadeftyde on oxidation by Na, Cr,O/H SO, gives:

• A. CH3COOH✓
• B. C2H5OH
• C. OHC.OHC
• D. None of above

Explanation: An aldehyde on oxidation with an oxidizing agent (such as one given in qs) gives its respective carboxylic acid. A is a carboxylic acid.

Q92. Which is the correct formula of ammonium carbamate?

• A. H2NCONH2
• B. NH4COONH4
• C. H2NCOONH2
• D. NH2COONH4✓

Explanation: Ammonium carbamate is a salt formed by the reaction of ammonia with carbon dioxide or carbamic acid. It has formula [NH₄][H₂NCO₂]. The reaction for its formation is 2NH 3 + CO 2 → [NH 2CO 2][NH 4]

Q93. Uncertainly principle can be expressed as:

• A. Apax-h
• B. AEA-h
• C. both (a) and (b)✓
• D. None

Explanation: The uncertainty principle arises from the wave-particle duality. A quite accurate measurement of one observable involves a relatively large uncertainty in the measurement of the other It is expressed in terms of a particle's momentum and position, i.e. p x=h and can alternatively be expressed in terms of Energy and time, i.e., E T=h, so option C is correct.

Q94. The equilibrium constant for a reaction N2 (g)+O2 ------ 2NO is 4 x 10 at 2000 k in the presence of a catalyst. Equilibrium is attained 10 times faster. The equilibrium constant in the presence of a catalyst at 2000 k

• A. 10×10
• B. 4x10
• C. 40 x 10✓
• D. 4x10

Explanation: Equilibrium constant for a reaction depends on temperature and is constant for a particular reaction at a particular temperature. It is not effected by the presense of a catalyst. Hence even in the presence of a catalyst its value remains same which is option C. The remaining options are wrong in this case.

Q95. The lowest vapor pressure is exerted by:

• A. Water
• B. Kerosene oil
• C. Mercury✓
• D. rectified spirit

Explanation: Vapor pressure is inversely proportional to the strength of intermolecular forces. Hence, as the order of increasing intermolecular forces increases, Kerosene oil <rectified spirit <water and mercury So the order of increasing vapour pressure will be Kerosene oil > distilled spirit >water >mercury So mercury will have the lowest vapor pressure among the givens.

Q96. 1 atomic mass unit (amu) in terms of energy is nearly equal to:

• A. 931 KeV
• B. 931 MeV✓
• C. 39 MeV
• D. 139 Kev

Explanation: The mass-energy equivalence concept is mathematically represented by the famous equation: E=mc2 Using this equation, we will convert 1 atomic mass unit (amu) to its energy equivalent 1 amu = 1.66054x10 -27 kg C is the speed of light in m/s, which is equal to 3 x 108 m/s E =mc2 E = 1.66054x10 -27 * (3X10 8)2 =1.49x10 -10 J CONVERTING THE ENERGY FROM JOULE TO ELECTRON VOLT 1MeV=1.6X10-13 J So 1.49 x 10-10/ 1.6 x 10-19 = 931 MeV

Q97. Which of the following reaction show nucleophilic substitution of alkyl halideR-X?

• A. RX+H
• B. RH+HX✓
• C. 2RX+2Na-R-R+2NX
• D. R-X Mg-RMX

Explanation: The reaction of RX with KCN is a neucleophilic substitution reaction, as CN is a nucleophile that attacks the electrophilic carbocation.

Q98. A metal form strong base salts and stable carbonates. The metal is:

• A. Transition metal
• B. Alkali metal✓
• C. Alkaline earth metal
• D. None of above

Explanation: Group 1 elements form strong bases, hence form strong base salts, and have stable carbonates due to the low polarising power of metal cations (which is due to their large cationic size and low charge). Group 1 elements are called Alkali metals (option B) The remaining options A and C do not fit the given criteria precisely

Q99. Which of the following oxy acids of chlorine is least oxidizing in nature"?

• A. HOCl✓
• B. HCIO2
• C. HClO3
• D. HClO4

Explanation: The oxidizing power of oxy acids of halogens increases as the oxidation number of the halogen in the compound increases. HOCl has the lowest oxidation number of Chlorine in it (+1), so it is the least oxidizing agent. Oxidation numbers for chlorine in B, C, and D are HClO2 = +3, HClO3 = +5, and HClO4 = +7, which are all higher than +1, so A is the correct option.

Q100. Which one is non-polar but contains polar bonds:

• A. HCl
• B. HF
• C. H2O
• D. CO2✓

Explanation: HCl, HF, and H2O is polar and contains polar bonds. (options A, B, and C). CO2 (option D) contains polar bonds as O is more electronegative than C, so electrons are unequally shared, but due to its symmetry, the dipoles are cancelled and the molecule is non-polar.

Q101. Which of the following is correct?

• A. Molecularity of a reaction is same as the order of reaction
• B. In some cases molecularity of a reaction is the same as order of reaction✓
• C. Molecularity of a reaction is more than order of reaction
• D. All are correct

Explanation: Molecularity of a reaction is sometimes same as the order of reaction, because order of reaction is experimentally derived. It is not necessary that molecularity is always same sa that of order of reaction.

Q102. O2 gas is chemically inert at room temperature because:

• A. Atoms in the O2 molecules are held by multiple bonds✓
• B. 0-0 bonds are strong
• C. The amount of metal in the anode
• D. All of the above

Explanation: Atoms in an Oxygen molecule are held together by a double bond. O-O single bonds have a bond length of 1.48 angstrom, while O-O double bonds have a bond length of 1.21 angstrom. Double bonds are stronger because they hold the atoms closer together and make them difficult to break. Hence, more energy is required to break multiple bonds as compared to single bonds. Oxygen-to-oxygen double bonds are strong and hence cannot be easily broken under ordinary conditions. It requires at least 495 kJ/mol of energy to cause an oxygen molecule to dissociate into monoatomic oxygen. As such, a large amount of energy is not readily available, so it makes the oxygen molecule stable over a wide range of temperatures.

Q103. 2% solution by weight of sodium chloride solution is prepared. The molality of the solution is:

• A. 0.34 molal✓
• B. 0.25 molal
• C. 2 molals
• D. 0.02 mol

Explanation: 2% solution by weight means 2 grams of NaCl is dissolved per 100 grams of water. No. of moles = given mass/ molar mass = 2/58.5 = 0.034 Molality = no of moles / mass of solution in kg = 0.034/0.1= 0.34 Molal

Q104. For a reversible reaction to reach on equilibrium state the reaction said to be carried out in

• A. Glass vessel
• B. Iron vessel
• C. Open vessel
• D. closed vessel✓

Explanation: At equilibrium, the rate of forward reaction equals the rate of reverse reaction. There is no net change in the concentration of the substances involved. This must happen in a closed vessel so that no reactant or product is allowed to escape and the total concentration of the reaction mixture remains constant. If any of the reactants or products manage to escape, the reaction will no longer be in equilibrium.

Q105. Which of the following is a cycloalkane?

• A. C6H14
• B. C6H12✓
• C. C6H10
• D. C6H0

Explanation: C6H12 follows the formula CnH2n, which is the general formula for cycloalkanes. Cycloalkanes have two Hydrogen atoms less than their parent alkane. Cycloalkanes share the same general formula with alkenes.

Q106. The uncertainty principle can be expressed as:

• A. Apax-h
• B. AEA-h
• C. both (a) and (b)✓
• D. None

Explanation: The uncertainty principle arises from the wave-particle duality. A quite accurate measurement of one observable involves a relatively large uncertainty in the measurement of the other It is expressed in terms of a particle's momentum and position, i.e. p x=h and can alternatively be expressed in terms of Energy and time, i.e., E T=h, so option C is correct.

Q107. Reason for alkali metals to be soft is that

• A. They are less metallic in nature
• B. There is only one valency
• C. They do not having tightly packed structures✓
• D. They have high IE

Explanation: Alkali metals have lower densities. They have a large atomic size with only one valence electron. Therefore, they have weaker metallic bonds between atoms. The close packing of atoms is weak. Hence, they are soft. The softness of alkali metals increases as you move down the group.

Q108. If water samples are taken from a sea, river, cloud, lake, or snow, they will be found to contain hydrogen and oxygen in the ratio of 1:8 by weight. This indicates the law of:

• A. Definite proportion✓
• B. Multiple proportion
• C. Reciprocal proportion
• D. None of above

Explanation: The law of constant composition states that a given chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source or method of preparation. A sample of H₂O from any source will have hydrogen and oxygen in a ratio of 1:8 by mass. (Mass ratio in H2O = 2:16 = 1:8).

Q109. If the pressure and temperature (k) of two liters of CO2 are doubled the volume of CO2 would become:

• A. 5 liters
• B. 4 liters
• C. 8 liters
• D. 2 liters✓

Explanation: As PV=nRT or V =nRT/P Using P’=2P and T’=2T, we get V’= 2nRT/2P V’= nRT/P V’= V So , the volume will be 2 litres.

Q110. How many atoms are contained in one mole of Ca(OH)2?

• A. 5 x 6.02 x 1023 atoms✓
• B. 30 x 6.02 x1023
• C. 3x x 6.02 x 1023
• D. 6 x 6.02 x 1023

Explanation: The number of atoms in one mole of substance can be calculated by No. Of atoms = atomicity X Avogadro's no. As a molecule of Ca(OH)2 contains 5 atoms (1Ca, 2O, and 2H), its atomicity is 5. So number of atoms in one mole of Ca(OH)2 will be 5 x 6.022 x 1023 atoms.

Q111. Lowering in vapour pressure is the highest for:

• A. 0..2M urea
• B. 0.1 M Glucose
• C. 0.1 M MgSO4
• D. 0.1 M BaCl2✓

Explanation: The higher the vanthoff factor, the greater the lowering of vapor pressure. The highest van der hoff factor is for BaCl2On dissociation, it gives 3 moles of ions (2 chloride and one barium). So the highest lowering of vapor pressure will be for BaCl2.

Q112. The oxidation number of chlorine in Ca(ClO3)2

• A. -1
• B. +3
• C. +5✓
• D. -6

Explanation: This has to be calculated The oxidation state of Ca is +2, and oxygen is -2, so: (+2) + (2x) + (6 x -2) = 0; calculating this gives x = +5

Q113. Fast neutrons can be slowed down by collisions with:

• A. Electrons
• B. Protons✓
• C. Phonons
• D. Photons

Explanation: A nuclear reactor is a device in which nuclear reactions are initiated,maintained,and controlled.It works on the principle of controlled chain reactions and provides energy at a constant rate.The moderator in a nuclear reactor slows down fast-moving secondary neutrons produced during fission.These moderators are rich in protons.When fast-moving neutrons collide head-on with the protons of moderator substances,their energies are interchanged, and thus the neutrons are slowed down.

Q114. CH3CH2l reacts with dry Ag2O to give

• A. Diethyl ether
• B. Ethane
• C. Ethanal
• D. Ethanol✓

Explanation: The reaction that takes place is as follows: 2C2H5Br + Ag2O ----------- C2H5OC2H5 + 2AgBr

Q115. The constancy of the e/m ratio of electrons shows that:

• A. Electron mass is 1/87th of proton
• B. Electron are universal particles of all matter✓
• C. Electrons are produced in discharge
• D. None of the above

Explanation: The constancy of the e/m ratio for electrons despite variations in the gas present in the discharge tube or in the material of the cathode shows that electrons are universal constituent particles. Electrons are present in all elements in their standard state, and the individual properties of electrons are the same for every element.

Q116. Which one of the following acids has the highest PH value?

• A. HCl(aq)
• B. HNO3 (aq)
• C. HF (aq)✓
• D. H2SO4(aq)

Explanation: As the pH of an acid increases, the strength of the acid decreases. Acid strength describes the tendency of an acid to dissociate (split into its ionic constituents in an aqueous solution). HF has the highest pH (about 3). It is a weak acid as it fails to completely dissociate in aqueous solution as the bond between H+ and F- is very strong since F is highly electronegative. HCl has a very low pH (close to 1). HNO3 also has a Low pH around 1.6. H2SO4 pH is around 2.3. HCl has the lowest pH as it is the strongest acid. It completely dissociates in an aqueous solution.

Q117. When a wave is reflected while entering from rarer medium to a denser medium, then at the boundary, the reflected wave undergoes a phase change of

• A. 0°
• B. 180°✓
• C. 90°
• D. 45°

Explanation: When the transverse wave travels from the rarer medium to the denser medium, it gets reflected from the denser medium, where a phase change of π radian or 1800 occurs.

Q118. The magnitude of the resultant of two forces is F. The magnitude of each force id F. The angle between the forces must be:

• A. 20°
• B. 60°
• C. 120°✓
• D. 45°

Explanation: If we know the magnitude of two forces and the angle between them, we can find the magnitude of the resultant force by applying the following formula: R=√A2+B2+2ABcosθ​ Given that the two forces are of equal magnitude =F and the resultant of these forces =F F=√F2+F2+2F2cosθ F2=2F2(1+cosθ) cosθ=−1/2 θ=120∘ Final answer:120∘

Q119. The maximum KE of an emmitted photoelectrons depends on:

• A. intensity of the incident light
• B. frequency of the incident light✓
• C. temperature of the photosensitive surface
• D. None of the above

Explanation: The maximum KE of emitted photoelectrons depends on the frequency of incident light This can be represented by the photoelectric equation Ek = hf + w Where Ek is the maximum kinetic energy of emitted photoelectrons, h is the Planck's constant, f is the frequency of incident light and w is the work function For a given material, w remains constant, so the maximum kinetic energy is dependent on the frequency.

Q120. The half-life of a radioactive source is 2.3 days. Its decay constant per day will be:

• A. 0.1
• B. 0.2
• C. 0.3✓
• D. 2.3

Explanation: T1/2 = 0.693/λ. Where T1/2= half life and λ= decay constant When half life= 2.3 days So λ = 0.693/T1/2 = 0.693/2.3 =0.30 per day

Q121. The first law of thermodynamics can be expressed mathematically as:

• A. Δθ= Δu + Δw✓
• B. Δθ =Δ u
• C. Δθ =Δw
• D. None

Explanation: First law of thermodynamics states “ energy can neither be created nor destroyed, it can only be altered/changed into different forms”. Δθ= Δu + Δw is one of the mathematical expression for first law of thermodynamics which explains that heat supplied to the system(Δθ) is equal to change in internal energy of the system(Δu) plus work done by the system on the surrounding(Δw).

Q122. The frequency of the fundamental mode of a string stretched by a tension / and having mass m and length l is given by:

• A. f=½ √T/ml
• B. f= 1/2l √Txl/m✓
• C. f- 1/2l√T/m
• D. f=1/2√T/m

Explanation: Explanation for this question will be added soon.

Q123. What will be the effect on the speed of transverse waves on a string if the tension in the string remains constant but the diameter of the string becomes double?

• A. Remains constant
• B. Becomes Half✓
• C. becomes double
• D. Becomes four times

Explanation: As v=sqrt(T/d), Where T is tension and d is linear density of the string Also,d=m/l(mass per unit length) And mass is directly proportional to Area which is directly proportional to square of diameter Thus,doubling diameter quadruples the linear density. As v=1/sqrt(d), The speed will be cut in half by doubling diameter.

Q124. A laser is a device that can produce:

• A. Intense beam of light
• B. Coherent beam of light
• C. Monochromatic beam of light
• D. All of the above✓

Explanation: A laser is a device that produces an intense, coherent, and monochromatic beam (made of rays) of light. Laser light is different from typical light sources as the beam produced is coherent and monochromatic. Coherent refers to the fact that all the light rays in the beam are in phase, i.e., the troughs of all the light waves in the beam line up together, as do all the crests. Laser light is monochromatic, which means all of the light produced by the laser is of a single wavelength.

Q125. A particle is moving in a circle of radius r with a constant angular speed . Its acceleration directed towards the center of the circle is:

• A. w/r
• B. w2/r
• C. w2r✓
• D. wr2

Explanation: The formula for angular acceleration is a= = w2r R Centripetal acceleration = V2/r, whereby V=rW, thus (rW)2 / r is = w2 r

Q126. A string passes over a smooth pulley and carries a 3kg mass at one end and a 5kg mass at the other end. The acceleration of the masses is:

• A. 2.45m✓
• B. 0.25 ms
• C. 0.25 ms
• D. 2.8 ms

Explanation: F=ma F is resultant force Force by 3 kg mass is 3 x 9.81 = 29.43 N BY 5 kg mass is 5 x 9.81 = 49.05 N The resultant force is 49.05-29.43 = 19.62N 19.62/8 (total mass ) =2.45 ms^-2

Q127. Rest mass energy of an electron is:

• A. 0.511 MeV✓
• B. 1 MeV
• C. 8.0x10 J
• D. None of above

Explanation: Eo=moc^2 Where, c2= velocity of light which is 3×10^8 m/s mo=rest mass of an electron which is 9.11×10−31 kg Eo=rest mass energy Put value of rest mass of an electron and velocity of light in above equation, We get, Eo=9.11×10−31 × (3×10^8)^2 Solve this we get, Eo=8.91×10^−14 J We can convert joule into eV, as our options are also in eV. We know that, 1J=1.6×10−19 eV Eo= (8.91×10^−14) / (1.6×10^−19 eV) Eo =0.511MeV

Q128. As compared to a stationary clock, a moving dock clicks: rate as stationary clicks

• A. Slower✓
• B. faster
• C. Same
• D. Clicks negative time

Explanation: According to Einstein’s Special Theory of Relativity, Time for a moving reference frame actually slows down compared to a “stationary” observer. This works in principle no matter what kind of clock is used, e.g., a wrist watch, crystal oscillator, atomic clock, an hourglass filled with sand, or even a clock made from bouncing light in a mirror setup (which served as Einstein’s original thought experiment). All of this is possible because time itself slows, regardless of how it is measured. According to Einstein’s theory, the amount that time slows is more pronounced the faster an object travels through space (especially as its velocity gets closer to the speed of light); however, at typical speeds encountered in our everyday lives, there is essentially no change in time due to Relativity. For clocks that move at a constant speed, the time change (time dilation) is constant, whereas when clocks are being accelerated (whether linearly or in a gravitational field), the amount of time dilation is governed by Einstein’s General Theory of Relativity. Both Einstein’s Special Theory of Relativity and General Theory of Relativity have been confirmed in every single experiment performed (within the margins of error), except they aren’t compatible with Quantum Mechanics.

Q129. The net change in entropy in the Carnot cycle is:

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

Explanation: The Carnot Cycle is a thermodynamic cycle that consists of four subsequent reversible processes: isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression.Entropy does not change during adiabatic processes because dQ is 0.

Q130. Which of the following has the high energy photon?

• A. Visible light
• B. X-rays
• C. Ultraviolet light
• D. γ-rays✓

Explanation: Gamma rays have the highest energy.

Q131. Two boats moving parallel in the same direction:

• A. Will be pulled towards each other✓
• B. Will be pulled towards each other
• C. Will have no effect on each other
• D. None

Explanation: As the speed of water between the ships is greater than outside them, pressure between them gets reduced, and pressure outside is greater, so the excess pressure pushes the ships closer to each other, therefore they get attracted to each other and are pulled towards each other.

Q132. A well-stoppered thermos flask containing some ice cubes is an example of:

• A. closed system
• B. open system
• C. isolated system✓
• D. None of above

Explanation: Thermoflask will not allow the exchange of matter and energy with the surrounding environment. Hence, it is an example of an isolated system.

Q133. Two parallel wires are carrying current in opposite directions. These two wires

• A. will attract each other
• B. will repel each other✓
• C. will have no effect on each other
• D. None of the above

Explanation: If two parallel wires carry current in opposite directions, they repel each other, whereas if two parallel wires carry current in the same direction, they attract each other.

Q134. The applied force that the solid can withstand without breaking is called:

• A. Stiffness of solids
• B. Strength of solid✓
• C. Ductility of solids
• D. Toughness of solid

Explanation: Strength measures how much stress can be applied to an element before it deforms permanently or fractures.

Q135. As the temperature of the black body increases, the wavelength of maximum intensity radiation increases:

• A. will shift towards the longer wavelength
• B. will shift towards the shorter wavelength✓
• C. will not change
• D. None of these

Explanation: As the temperature of the blackbody increases, the peak wavelength decreases (Wien's Law). The intensity (or flux) at all wavelengths increases as the temperature of the blackbody increases.

Q136. The decay of one radioactive atom per second is equal to

• A. one Becquerel
• B. One curie✓
• C. One-half life
• D. None of above

Explanation: One becquerel is the quantity of a radioactive element in which there is one atomic disintegration per second.

Q137. If a shell explodes in the air, its fragments fly in different directions. The total momentum of the fragments

• A. Increase
• B. decreases
• C. remains constant✓
• D. none of the above

Explanation: Initially the shell will be stationary and hence have zero momentum. After explosion the fragments of shell will fly apart in different directions and the sum of their momenta will also be equal to zero so as to obey Law of conservation of momentum. The law of conservation of momentum states that the total linear momentum of an isolated system remains constant. Since the momentum before and after are both zero, options A and B are wrong (as they talk about an increase or decrease in momentum). Option C says it remains constant, which is the correct answer.

Q138. IF a material particle starts motion with speed equal to the speed of light, then mass of the moving particle will:

• A. Remain constant
• B. Become zero
• C. become equal to rest mass of particle
• D. Become infinite✓

Explanation: Using the formula for mass dilation When an object travels at v = c, the factor becomes equal to zero. Dividing mo by zero leads to mass becoming equal to infinity.

Q139. The range of a projectile is the same for two angles that are mutually exclusive:

• A. orthogonal
• B. supplementary
• C. complementary✓
• D. sum is 45°

Explanation: The range of the projectile is equal for angles whose sum is equal to 90.

Q140. The vectoral form of centripetal force is:

• A. Fe = mv2/r
• B. Fe=(mv2/r)^γ✓
• C. Fe=(mv2/r2)^γ
• D. Fe=(mv2/r2)^γ

Explanation: Magnitude of centripetal force Fc=mv2/r For vector form, we multiply it with unit vector ^r to get Fc = (mv)2/r)^γ

Q141. A 50-m coil carries a current of 2 amperes. The energy stored in a magnetic field is:

• A. 10 joule
• B. 0.1 joule✓
• C. 0.01 joule
• D. 1.0 joule

Explanation: Using the formula for energy stored in magnetic field of a coil (E = ½ × L × I²) E = ½ × L × I² E = ½ × (50 × 10-3) × (2)² = 0.1 J

Q142. A body of mass 1 kg is suspended from a balance in the elevator, which is accelerating downward with an acceleration of 4ms-1 the reading of the balance will be:

• A. 9.8 N
• B. 13.8 N
• C. 5.8 N✓
• D. Zero

Explanation: Reading = mg - ma = (1)(9.8) - (1)(4) =9.8 - 4 =5.8N

Q143. The radio waves of constant amplitude are called:

• A. Modulated waves
• B. Carrier waves✓
• C. Standing waves
• D. Rectified waves

Explanation: Such waveforms are used in modulation. Modulation is the process of converting data into radio waves by adding information to an electronic or optical carrier signal. A carrier wave is the continuous electromagnetic radiation of constant amplitude and frequency that is given out by a transmitter.

Q144. The resolving power of the lens can be improved by using

• A. Lens of short focal length
• B. Lens of large focal length
• C. Light of short wavelength✓
• D. Light of large wavelength

Explanation: Resolution depends on the wavelength of the light source. The smaller the wavelength, the greater the resolution. Hence, option D is wrong, and option C is the correct answer here. It is independent of focal length, so options A and B are wrong.

Q145. If the length of second pendulum becomes four times, then its time period will become:

• A. Four times
• B. Two times✓
• C. Half
• D. one fourth

Explanation: Using the formula for simple pendulum

Q146. A close surface contains equal and opposite charges. The net electric flux through the close surface is

• A. maximum
• B. minimum
• C. Zero✓
• D. positive as well as negative

Explanation: The surface has an equal number of positive and negative charges, so the net charge will be zero. Guass’s law suggests that Ф = net charge / ∈₀, by using Q = 0, then Ф = 0. Hence, C is the correct option.

Q147. Critical angle of a medium depends upon the:

• A. Speed of light
• B. wavelength of light
• C. Refractive index of the medium✓
• D. intensity of light

Explanation: The critical angle is the angle of incidence, which corresponds to an angle of refraction of 90 degrees when light travels from a denser to a rarer medium.

Q148. The phase change of 180 is equivalent to a path difference:

• A. λ/2✓
• B. λ
• C. 2λ
• D. 4λ

Explanation: A change of phase of 180 degrees, or ,π is equivalent to a path difference of λ/2.

Q149. The unit of conductance is

• A. Ohm
• B. Ohm-meter-1
• C. Ohm - meter
• D. mho✓

Explanation: The SI unit for conductance is siemen or mho. This is also written as 1/ohm or ohm-1. Ohm is the unit of resistance while ohm-meter is the unit of electrical resistivity.

Q150. At what place will the motion of the bob of the simple pendulum be the slowest?

• A. At poles of earth
• B. At equator of earth✓
• C. Anywhere on the surface of earth
• D. None of these

Explanation: The value of “g” is lowest at the equator. As T = 2π √L/g, so the Time period will be maximum hence the it would take more time to complete one oscillation.

Q151. If the resultant of two vectors each of magnitude A is the ,angle between the vectors will be:

• A. 30°
• B. 45°
• C. 60°
• D. 120°✓

Explanation: It is given that two vectors are equal in magnitude i.e. if A and B are two vectors then ∣A∣=∣B∣. It is also mentioned that the magnitude of resultant is equal to the magnitude of either of them i.e. ∣A∣=∣B∣=∣A+B∣…… Eq(1)

Q152. The current gain of a transistor having a collector current of 10 mA and a base current of 40 A is:

• A. 2.5
• B. 25
• C. 250✓
• D. 2500

Explanation: Current gain is the ratio of the change in the collector current to the change in the emitter current in a transistor. Mathematically α=△Ic/△Ie. Current gain = 1X10 -3 / 4X10 -6 =250

Q153. LASER light is the result of

• A. Spontaneous emission
• B. Ordinary emission
• C. Absorption of radiation
• D. Stimulated emission✓

Explanation: Laser stands for Light Amplification by Stimulated Emission of Radiation. Laser light utilizes stimulated emission. Stimulated emission requires the presence of a photon. An “incoming” photon stimulates a molecule in an excited state to decay to the ground state by emitting a photon. The stimulated photons travel in the same direction as the incoming photon. As a result a coherent, monochromatic and intense beam of laser light is created. For stimulated emission to be the dominant process, the excited state population must be larger than the lower state population. This is achieved by excitation of the lasing atoms or molecules - this is called PUMPING.

Q154. If there are coplanar forces acting on a body to keep it in equilibrium, then these forces are:

• A. Concurrent✓
• B. Non-concurrent
• C. Parallel
• D. Anti-parallel

Explanation: “A group of forces acting on an object is called a coplanar system of forces if the line of action of all the forces lies in the same plane.” A coplanar force system is considered a concurrent coplanar force system if the line of action of all the forces passes through the same point. For the given case of three forces, when three or more coplanar forces are acting at a point and the vector diagram closes, there is no resultant. The forces acting at the point are in equilibrium. When three or more coplanar forces are acting at a point and the vector diagram closes, there is no resultant. The forces acting at the point are in equilibrium.

Q155. The dimensions of angular acceleration are:

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

Explanation: Explanation: α = Δ ω/ Δ t α = T-1/T α = T-1-1 α = T-2

Q156. The resistance of the three arms of the balanced wheat stone bridge is 50 ohms. The resistance in the 4 ohm range is:

• A. 25ohm
• B. 50 ohm✓
• C. 75 ohm
• D. 100 ohm

Explanation: X= RQ/P X= 50x50/50 = 50 ohms

Q157. Which of the following is a conservative field?

• A. Gravitational field
• B. Electric field
• C. Magnetic field
• D. All such fields✓

Explanation: The field in which work is done independently of the path followed is called the conservative field. Gravitational fields, electric fields, and magnetic fields are some examples.

Q158. Newton's rings are formed due to:

• A. Diffraction of light
• B. Interference of light✓
• C. Polarisation of light
• D. Reflection of light

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

Q159. The number of photoelectrons emitted per second from the metal surface depends upon

• A. Intensity of light✓
• B. Frequency of light
• C. Wavelength of light
• D. Speed of light

Explanation: According to Planck's quantum theory, the intensity of the incident beam is directly related to the number of photons in the beam. If the intensity of the beam increases, the number of photons will also increase. As the number of photons incident on the metal surface increases, the number of photoelectrons emitted from the metal will also increase.

Q160. The process in which heat neither enters nor leaves the system but still changes the temperature of the system is

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

Explanation: Adiabatic is a process in which heat neither enters nor leaves a system, but the temperature of the system still changes.

Q161. The transition from n = 4,5,6,.......... To n+3 in hydrogen spectrum gives

• A. Balmer series
• B. Lyman series
• C. Paschen series✓
• D. Pfund series

Explanation: When an electron transitions from a higher energy state to a lower energy state, it releases electromagnetic radiation that falls into certain series. The series are determined by what level of n the e transitions to, such that: Transitions ending in n = 1 fall into the Layman series, while transitions ending in n = 2 fall into the Balmar series. Those transitions that end in n = 3 fall into the Paschen series.

Q162. The applied force which the solid can withstand without breaking is called

• A. Stiffness of solids
• B. Strength of solid✓
• C. Ductility of solids
• D. Toughness of solid

Explanation: Strength measures how much stress can be applied to an element before it deforms permanently or fractures.

Q163. If the moveable mirror is displaced through distance of 0.05 mm, 200 fringes are observed shifted. The wavelength of light used is:

• A. 5x100
• B. 5x10m
• C. 500 nm✓
• D. 50mm

Explanation: This question deals with a Michaelson interferometer. The Michelson interferometer produces interference fringes by splitting a beam of light so that one beam strikes a fixed mirror and the other a movable mirror. When the reflected beams are brought back together, an interference pattern results. For a Michaelson interferometer: nλ=2Δx λ = 2Δx/n λ = 2* 0.05/200 = 0.0005 mm or 5x10-4 mm 1 mm = 1x10 +6 nm 5x10-4 mm = 5x10 +2 nm or 500 nm

Q164. The resultant of a 6N force and an 8N force acting at right angles to each other is of the magnitude:

• A. 14 N
• B. 2N
• C. 10N✓
• D. 48 N

Explanation: When two forces are acting at right angles to each other, the resultant can be calculated by using the Pythagorean Theorem. One of the forces represents the base (B) of a right-angled triangle, and the other force represents the perpendicular (P). The result of the forces is the hypotenuse (H). Acc to Pythagoras' theroem, H2= P2+ B2 H2= 6X6 + 8X8 H2= 36+64 H2=100 Taking sq root, H=10N which is the resultant.

Q165. An important site for formation of glycoproteins and glycolipids is

• A. Vacuole
• B. Golgi apparatus✓
• C. Plastid
• D. Lysosome.

Explanation: Eukaryotic cells contain a unique cluster of membrane vesicles known as the Golgi apparatus. It principally performs the function of packaging materials. The newly synthesized proteins are handed over to the Golgi apparatus which is causes the addition of carbohydrates, lipid or sulphates moieties to the proteins. Golgi apparatus is an important site for the formation of glycoproteins and glycolipids.

Q166. Which one of the following is not considered as a part of the endomembrane system?

• A. Golgi complex
• B. Peroxisome✓
• C. Vacuole
• D. Lysosome

Explanation: While each of the membranous organelles is distinct in terms of its structure and function, many of these are considered together as an endomembrane system because their functions are coordinated. The endomembrane system include endoplasmic reticulum (ER), Golgi complex, lysosomes and vacuoles. Since the functions of the mitochondria, chloroplast and peroxisomes are not coordinated with the above components, these are not considered as part of the endomembrane system.

Q167. The figure below shows the structure of a mitochondrion with its four parts labelled A, B, C and D. Select the part correctly matched with its function.

• A. D (outer membrane) – gives rise to inner membrane by splitting
• B. B (inner membrane) – forms infoldings called cristae✓
• C. C (crista) – possesses single circular DNA molecule and ribosomes
• D. A (matrix) – major site for respiratory chain enzymes

Explanation: Each mitochondrion is a double membrane­ bound structure with the outer membrane and the inner membrane dividing its lumen distinctly into two aqueous compartments, i.e., the outer compartment and the inner compartment. The inner compartment is called the matrix. The outer membrane forms the continuous limiting boundary of the organelle. The inner membrane forms a number of infoldings called the cristae towards the matrix. The cristae increase the surface area. The two membranes have their own specific enzymes associated with the mitochondrial function.

Q168. The plasma membrane consists mainly of:

• A. Phospholipids embedded in a protein bilayer
• B. Proteins embedded in a phospholipid bilayer✓
• C. Proteins embedded in a polymer of glucose molecules
• D. Proteins embedded in a carbohydrate bilayer.

Explanation: Plasma membrane consists of lipids (20-­40%), proteins (60­-80%), carbohydrates (1-­5%) and water . Lipid molecules possess both hydrophobic and hydrophilic ends and are thus arranged in the form of lipid bilayer. The most common lipids of the bilayer are phospholipids. Protein molecules occur at places both inside (intrinsic proteins) and on the outer side (extrinsic proteins) of the phospholipid bilayer.

Q169. The main area of various types of activities in a cell is the:

• A. Plasma membrane
• B. Mitochondrion
• C. Cytoplasm✓
• D. Nucleus

Explanation: Cytoplasm is a granular, crystallo-­colloidal complex that forms the living protoplasm of a cell excluding its nucleus. It consists of proteins, nucleic acids, fats, carbohydrates, vitamins, minerals, waste metabolites, and all the organelles. It is the main area for various types of activities of a cell like respiration, nutrition, storage, etc.

Q170. Which one of the following has its own DNA?

• A. Mitochondria✓
• B. Dictyosome
• C. Lysosome
• D. Peroxisome

Explanation: Mitochondria have their own DNA. They are double-membraned organelles found in eukaryotic cells responsible for producing energy through cellular respiration.