Sindh Mcat Nts 2012 Lumhs — Solved Past Paper with Answers

Q1. Identify the word or phrase that needs to be changed for the sentence to be correct:One of tiger from the circus has got loose. No error.

• A. Tiger✓
• B. From
• C. Has got
• D. Loose
• E. No error

Explanation: The correct answer is Option A: 'Tiger.' The sentence requires the definite article 'the' before 'tiger' to correctly refer to a specific tiger from the circus. This is because the sentence implies that we are talking about a particular tiger that is already known within the context. The other options are correct as they are: 'From' is the correct preposition to indicate the origin, 'has got' is an acceptable expression to indicate the present perfect tense, and 'loose' accurately describes the state of the tiger. The option 'No error' is incorrect because there is indeed an error in the sentence regarding the missing article.

Q2. Identify the word or phrase that needs to be changed for the sentence to be correct:I prefer to read rather then to sit listening to the radio. No error.

• A. I prefer
• B. Read
• C. Then✓
• D. To the
• E. No error

Explanation: The correct answer is Option C: 'Then'. The sentence uses 'then', which is incorrect in this context. The word 'than' should be used because it sets up a comparison between 'reading' and 'listening to the radio'. 'Then' is used to indicate a sequence of events or time, which is not the case here. The other options are incorrect because the words and phrases are used correctly in their respective contexts.

Q3. Complete the sentences by choosing the most appropriate word, from the given lettered choices (A to E) below each.Children are _ the stairs.

• A. Running up and down✓
• B. Runs up and down
• C. Up and down running
• D. Up running and down running
• E. Up and down

Explanation: The correct answer is Option A: 'Running up and down'. This phrase correctly uses the present participle 'running' to describe the continuous action of the children. It matches the plural subject 'children' without adding unnecessary complexity or incorrect verb forms.Option B is incorrect because 'runs' is a singular form of the verb, which does not agree with the plural subject 'children'. Option C is incorrect because the phrase 'up and down running' disrupts the natural order needed to clearly convey the action. Option D is incorrect due to its redundant and awkward structure, making it grammatically unsound. Option E lacks a verb, leaving the sentence incomplete and thus incorrect.

Q4. Complete the sentences by choosing the most appropriate word, from the given lettered choices (A to E) below each.The spark set the carpet _ fire.

• A. In
• B. Up
• C. Of
• D. Out
• E. On✓

Explanation: The correct answer is 'on'. The phrase 'on fire' means that something is burning. This is a common expression in English to describe when something is ignited or ablaze. Other options like 'in', 'up', 'of', and 'out' do not form a grammatically correct or commonly used phrase to describe this action:'In fire' is not a recognized phrase.'Up fire' is also incorrect; although 'up in flames' is a valid expression, it does not fit this context.'Of fire' fails to convey the action of catching fire.'Out fire' would imply extinguishing a fire, which is the opposite of the intended meaning.

Q5. Choose the lettered word or phrase that is most nearly opposite in meaning to the word in capital letters.PEACEFUL:

• A. Passive
• B. Quarrelsome✓
• C. Loving
• D. Hearty
• E. Endless

Explanation: The word 'peaceful' describes a state of tranquility and absence of conflict. The correct opposite is 'quarrelsome,' indicating a tendency to argue or create conflict. 'Passive' suggests inaction, which isn't directly opposed to peaceful. 'Loving' conveys affection, similar to peacefulness. 'Hearty' implies vigor and enthusiasm, which doesn't conflict with peaceful. 'Endless' refers to duration, unrelated to the state of being peaceful or quarrelsome.

Q6. Choose the lettered word or phrase that is most nearly opposite in meaning to the word in capital letters.CONSTRUCT:

• A. Build
• B. Create
• C. Mould
• D. Destroy✓
• E. Submit

Explanation: The word 'CONSTRUCT' means to build or create something. Therefore, its opposite would be 'destroy', which means to ruin or demolish what has been built. The other options are either synonyms or unrelated: 'Build', 'Create', and 'Mould' are related to making or forming, whereas 'Submit' involves presenting or yielding, making 'Destroy' the correct opposite.

Q7. Fill in the blank:We finished the report but forgot to turn it _:

• A. Out
• B. Away
• C. In✓
• D. On

Explanation: The correct preposition is 'in' because the phrase 'turn in' is commonly used to describe the action of submitting something, such as a report or an assignment. The other options do not convey the appropriate meaning in this context. 'Out' suggests distribution, 'Away' implies distancing or storing, and 'On' indicates attachment, none of which relate to submission.

Q8. Choose the correct option:

• A. Despite being tried his best to persuade people to give up smoking, he could not attain success.
• B. Despite of his best trying to to persuade people to give up smoking, he could not attain success
• C. Despite trying his best to persuade people to give up smoking, he could not attain success.✓
• D. In spite of being tried his best to persuade people to give up smoking, he could not attain success.

Explanation: Option C is the correct choice because it uses the conjunction 'despite' correctly and maintains a logical and grammatically correct sentence structure. The phrase 'trying his best to persuade' correctly follows 'despite'.Option A is incorrect due to the unnecessary and incorrect use of 'being'.Option B is incorrect because 'despite of' is a grammatical error, and the repetition of 'to' is a typographical mistake.Option D is incorrect because 'being' is not needed and disrupts the grammatical flow of the sentence.

Q9. Choose the word most similar in meaning to the capitalized one.RESPONSIBLE:

• A. Accountable✓
• B. Dividable
• C. Unable
• D. Simple
• E. Creative

Explanation: The word Accountable is the correct choice because it implies an obligation or readiness to accept responsibility. When someone is accountable, they are answerable for their actions, similar to how someone responsible would be. Dividable, on the other hand, pertains to something that can be divided and does not relate to responsibility. Unable is about lacking capability, which contrasts with being responsible. Simple describes something uncomplicated, while Creative pertains to imaginative thinking, both of which are unrelated to the concept of responsibility.

Q10. Choose the word most similar in meaning to the capitalized one.FAST:

• A. Slow
• B. Lazy
• C. Relevant
• D. Quick✓
• E. Still

Explanation: The correct answer is 'Quick' because both 'fast' and 'quick' describe something occurring at a rapid pace. 'Slow' and 'still' are antonyms of 'fast', while 'lazy' and 'relevant' are unrelated in terms of meaning.

Q11. Sundew is an example of _.

• A. Autotrophic plant
• B. Parasitic plant
• C. Saprophytic plant
• D. Carnivorous plant✓
• E. Extinct plant

Explanation: Sundews (Drosera spp.) are carnivorous plants known for their sticky tentacles that trap insects. This adaptation allows them to thrive in nutrient-poor environments by supplementing their diet with the nutrients obtained from their prey. While they are capable of photosynthesis, their carnivorous behavior is what sets them apart. Other plant types, like autotrophic plants, rely solely on photosynthesis, parasitic plants derive nutrients from host plants, saprophytic plants decompose organic matter, and extinct plants no longer exist.

Q12. Respiratory organs in fish are called _.

• A. Lungs
• B. Skin
• C. Gills✓
• D. Tracheal system
• E. Stomata

Explanation: Fish gills are specialized organs that enable them to breathe underwater. They function by extracting oxygen from water and expelling carbon dioxide. The gills are located on both sides of a fish's head, protected by bony covers called opercula. Unlike lungs, which are used by land-dwelling vertebrates, or tracheal systems used by insects, gills are uniquely adapted for aquatic respiration. Other options like skin or stomata are related to different organisms or processes and do not apply to fish.

Q13. Pick the odd one out:

• A. Aorta
• B. Arteries
• C. Capillaries
• D. Veins
• E. Nephron✓

Explanation: The correct answer is Nephron. Nephrons are the structural and functional units of the kidney involved in the filtration of blood and urine formation. In contrast, the aorta, arteries, capillaries, and veins are all types of blood vessels with specific roles in the circulatory system. The aorta and arteries carry oxygenated blood from the heart, capillaries facilitate exchange between blood and tissues, and veins return blood to the heart. Thus, nephron is the odd one out as it pertains to the urinary system, not the circulatory system.

Q14. Flame cells are the _ organs in planaria.

• A. Reproductive
• B. Respiratory
• C. Digestive
• D. Locomotory
• E. Excretory✓

Explanation: Flame cells are specialized excretory cells found in simple freshwater invertebrates like flatworms, rotifers, and nemerteans. These cells are part of the protonephridia system and function similarly to kidneys by removing waste materials from the organism's body. This makes them excretory organs. Other options, such as reproductive, respiratory, digestive, and locomotory, refer to different systems that do not involve the function of flame cells.

Q15. Snail moves with the help of _.

• A. Foot✓
• B. Cilia
• C. Flagella
• D. Pseudopodia
• E. Shell

Explanation: Snails move using a muscular organ called the foot. This foot is adapted to create a gliding motion, facilitated by muscular contractions and mucus secretion. This allows the snail to move smoothly over surfaces. The other options refer to different structures that are not applicable to snails: cilia and flagella are involved in cellular movement in other organisms; pseudopodia are used by amoebas; and the shell serves as protection, not for movement.

Q16. Which one of the following is not true?

• A. True joints of elbow & knee are hinge joints
• B. The joint cavity is fitted with lubricating synovial fluid✓
• C. Bones of the skull are connected through fixed joints
• D. Hips & shoulder joints are the examples of ball and socket joints
• E. Cells of bones are called osteoblasts

Explanation: The correct answer is Option B: 'The joint cavity is fitted with lubricating synovial fluid'. This statement is not true for all joints. Only synovial joints feature a joint cavity filled with synovial fluid, which reduces friction and allows for smooth movement. Other joint types, such as fixed joints (like those in the skull) and hinge joints (like those in the elbow and knee), do not have synovial fluid-filled cavities. Option A is correct because hinge joints indeed allow movement in one plane. Option C is correct because the bones of the skull are immovably connected by fixed joints. Option D is correct because hips and shoulders are examples of ball and socket joints. Option E is correct because osteoblasts are indeed bone-forming cells.

Q17. Almost all the prokaryotes belong to the kingdom:

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

Explanation: The correct answer is Monera. This kingdom is specifically characterized by prokaryotic organisms, which are unicellular and lack a defined nucleus. Bacteria, the most common prokaryotes, belong to this kingdom. The other options, such as Fungi, Plantae, Animalia, and Protista, consist of eukaryotic organisms, which have complex cellular structures, including a defined nucleus, distinguishing them from prokaryotes.

Q18. The biological catalysts are called:

• A. Proteins
• B. Carbohydrates
• C. Vitamins
• D. Minerals
• E. Enzymes✓

Explanation: Enzymes are specialized proteins that function as biological catalysts, facilitating and accelerating various biochemical reactions by reducing the activation energy necessary. Although enzymes are proteins, not all proteins have catalytic functions, which differentiates enzymes from the broader category of proteins. Carbohydrates and minerals serve different roles in the body, such as energy provision and structural integrity, and are not involved in catalysis. Vitamins can act as coenzymes, enhancing enzyme function, but they do not act as catalysts themselves.

Q19. The chromosomes with equal arms resembling the letter ‘v’ are called:

• A. Telocentric
• B. Sub-metacentric
• C. Metacentric✓
• D. Acrocentric
• E. Autosomes

Explanation: Metacentric chromosomes are characterized by having the centromere located in the middle, which results in two arms of equal length, creating a 'v'-shaped appearance. This is distinct from other chromosome types such as telocentric, where the centromere is at one end, and sub-metacentric or acrocentric, where the arms are of unequal length. Autosomes refer to any non-sex chromosomes and do not specify the shape based on centromere position.

Q20. A viral reproductive cycle that culminates in death of best cell is known as:

• A. Lysogenic cycle
• B. Lytic cycle✓
• C. Krebs cycle
• D. Glycolysis
• E. Electron Transport Chain

Explanation: The lytic cycle is a viral reproductive cycle characterized by the infection of a host cell, replication of the viral genome, and the production of new viral particles. This cycle culminates in the lysis, or bursting, of the host cell, releasing new viruses to infect other cells. The lysogenic cycle, in contrast, involves the integration of viral DNA into the host's genome, allowing the virus to remain dormant until it enters the lytic phase. The Krebs cycle, glycolysis, and the electron transport chain are all metabolic pathways within cellular respiration, unrelated to viral cycles.

Q21. Bacilli bacteria are _ shaped.

• A. Spherical
• B. Spring
• C. Rod✓
• D. Screw
• E. Comma

Explanation: Bacilli bacteria are rod-shaped. The term 'bacilli' is derived from the Latin word for 'stick,' which reflects their elongated form. Other bacterial shapes include cocci (spherical), spirilla (spiral), spirochetes (screw-like), and vibrios (comma-shaped). The different shapes relate to variations in bacterial structure and movement.

Q22. _ is a typical protozoan that has both animal and plant like characteristics.

• A. Virus
• B. Euglena✓
• C. Ulva
• D. Paramecium
• E. Amoeba

Explanation: The correct answer is Euglena, which is a unicellular organism that exhibits both plant and animal traits. Euglena has chloroplasts that allow it to perform photosynthesis, similar to plants, and it also moves using a flagellum, a feature common in animal-like protists. In contrast, viruses are not living organisms and do not exhibit such characteristics. Ulva is an algae, not a protozoan, and does not have animal-like traits. Paramecium and Amoeba are both protozoans but lack the ability to perform photosynthesis, which is a plant-like characteristic.

Q23. Penicillin is produced by _.

• A. Bacteria
• B. Virus
• C. Algae
• D. Fungi✓
• E. Protozoa

Explanation: Penicillin is produced by the Penicillium mold, which is classified as a fungus. This mold was discovered to have antibiotic properties by Alexander Fleming in 1928. Fungi are unique in their ability to produce penicillin, setting them apart from other microorganisms such as bacteria, viruses, algae, and protozoa that do not produce this antibiotic. Bacteria are often the target of antibiotics rather than the producers, viruses lack the capability to produce substances like antibiotics, algae are more focused on photosynthesis, and protozoa are single-celled organisms without the metabolic capabilities for antibiotic production.

Q24. The segmented worms belong to the phylum _.

• A. Annelida✓
• B. Nematoda
• C. Porifera
• D. Mollusca
• E. Arthropoda

Explanation: Segmented worms belong to the Phylum Annelida, which is characterized by their segmented body structure. This phylum includes earthworms, leeches, and marine polychaetes. Unlike annelids, Nematoda are roundworms with unsegmented bodies; Porifera are simple, non-segmented sponges; Mollusca includes unsegmented mollusks like snails and clams; and Arthropoda, although segmented, consists of insects and crustaceans, not worms.

Q25. _ are exclusively marine invertebrates.

• A. Arthropods
• B. Echinoderms✓
• C. Protozoans
• D. Nematoda
• E. Platyhelminthes

Explanation: The correct answer is Echinoderms. This group is exclusive to marine environments and includes species such as sea stars, sea urchins, and sand dollars, all of which require saltwater to survive. In contrast, arthropods, protozoans, nematodes, and platyhelminthes can be found in a range of environments, including terrestrial and freshwater, and are not restricted to marine settings.

Q26. The botanical name of “brinjal” is:

• A. Solanum melongena✓
• B. Datura alba
• C. Solanum nigrum
• D. Solanum tuberosum
• E. Cestrum nocturnum

Explanation: The correct botanical name of brinjal, also known as eggplant, is Solanum melongena. This plant belongs to the nightshade family, Solanaceae, which includes several other well-known plants. The other options listed are either different species within the same family, such as Solanum nigrum (black nightshade) and Solanum tuberosum (potato), or entirely different plants such as Datura alba and Cestrum nocturnum.

Q27. Pyruvic acid is the end product of _.

• A. Krebs cycle
• B. Glycolysis✓
• C. Photosynthesis
• D. Anaerobic respiration
• E. Electron Transport Chain

Explanation: The correct answer is Glycolysis. Glycolysis is a sequence of enzymatic reactions that occurs in the cytoplasm of cells, where one molecule of glucose is broken down into two molecules of pyruvic acid. This process also results in the net gain of two ATP molecules and two NADH molecules. The other options describe different stages or processes in cellular respiration or photosynthesis that do not produce pyruvic acid as an end product. The Krebs cycle further processes pyruvate, anaerobic respiration can use pyruvate but does not produce it as an end product, the electron transport chain is involved in ATP production, and photosynthesis is unrelated to pyruvate production.

Q28. Wines and beers are formed due to _ process.

• A. Aerobic respiration
• B. Hydrolysis
• C. Hydrogenation
• D. Fermentation✓
• E. Decarboxylation

Explanation: The process of fermentation is essential in the production of wines and beers. During fermentation, yeast, a type of fungus, metabolizes sugars present in the grains or fruits, converting them into alcohol and carbon dioxide. This process does not require oxygen, making it an anaerobic process. Aerobic respiration, on the other hand, requires oxygen and is used primarily for energy production within cells, not alcohol production. Hydrolysis, hydrogenation, and decarboxylation are unrelated chemical processes that do not contribute to the formation of wines and beers.

Q29. Which one of the following genotypes cannot occur amongst the spring from a mating between a person of blood group A and a person of blood group B?

• A. AA✓
• B. AB
• C. A
• D. B
• E. O

Explanation: In a mating scenario between a person with blood group A and a person with blood group B, the possible genotypes for their offspring are AO, BO, AB, or OO, depending on the alleles each parent contributes. For genotype AA, the child would need to receive an A allele from both parents. However, since one parent is blood group B, they can only contribute a B or O allele, not an A allele. Therefore, AA is not a possible genotype. Other genotypes such as AB, A (AO), B (BO), and O (OO) are possible based on the combinations of alleles contributed by the parents.

Q30. A fruit flies, the gene for wing type is located on an autosomal chromosome. The allele for wild type wings is dominant over the allele for vestigial wings. If a homozygous dominant male fly is crossed with a female with vestigial wings. What percentage of their female progeny is expected to have wild type wings?

• A. 0%
• B. 25%
• C. 50%
• D. 75%
• E. 100%✓

Explanation: The male fruit fly is homozygous dominant for wild type wings, meaning he carries two dominant alleles. The female fly has vestigial wings, indicating she carries two recessive alleles. When crossed, each female progeny will receive one dominant allele from the father and one recessive allele from the mother, resulting in a heterozygous genotype. Because the wild type allele is dominant, all female progeny will exhibit the wild type wing phenotype. Therefore, 100% of the female progeny are expected to have wild type wings. Options A, B, C, and D are incorrect because they do not match the results of this genetic cross, where the presence of at least one dominant allele results in the wild type phenotype.

Q31. The first ever cloned sheep was named as _.

• A. Silly
• B. Dolly✓
• C. Jolly
• D. Honey
• E. Tommy

Explanation: Dolly the sheep was the first mammal to be cloned from an adult somatic cell, using a technique known as somatic cell nuclear transfer. Born in 1996 at the Roslin Institute in Scotland, Dolly was named after the singer Dolly Parton. Her successful cloning was a groundbreaking achievement in biotechnology and raised important ethical debates about cloning. The other names mentioned, such as Silly, Jolly, Honey, and Tommy, have no connection to this scientific breakthrough.

Q32. Darwin’s Theory was based on all of the following points except:

• A. Over reproduction
• B. Struggle for existence
• C. Variations and heredity
• D. Survival of the fittest
• E. Use and disuse of organs✓

Explanation: Darwin’s theory of natural selection is based on key principles such as over reproduction, the struggle for existence, variations and heredity, and survival of the fittest. These components describe how natural selection leads to evolution. However, the idea of 'use and disuse of organs' is not part of Darwin's theory; it is associated with Lamarck's theory of evolution. Lamarck proposed that traits developed or diminished through use or disuse could be passed on to offspring, which Darwin’s theory does not support. Thus, the correct answer is 'Use and disuse of organs', as it is the element not included in Darwin’s theory.

Q33. The decomposers of an ecosystem are:

• A. Parasites only
• B. Bacteria only
• C. Fungi only
• D. Bacteria and Fungi✓
• E. Producers only

Explanation: The correct answer is 'Bacteria and Fungi'. Decomposers, such as bacteria and fungi, are essential in breaking down dead organisms and recycling nutrients back into the ecosystem. They decompose organic material, returning vital nutrients to the soil. The other options are incorrect: parasites rely on living hosts and do not decompose dead matter, and producers are involved in creating energy-rich compounds, not decomposition.

Q34. The frozen soil in Tundra is called _.

• A. Ice soil
• B. Snow soil
• C. Frigid soil
• D. Permafrost✓
• E. Frosted soil

Explanation: The term 'permafrost' is used to describe soil that remains continuously frozen for at least two years, which is a common feature of the tundra biome. Unlike other types of cold soil, permafrost does not thaw completely during the summer months, although the top layer, known as the active layer, may melt. The other options are incorrect as they either refer to temporary conditions or lack the permanent frozen aspect inherent to permafrost.

Q35. _ are responsible for secondary sexual characteristics in male.

• A. Cortisol
• B. Androgens✓
• C. Thyroid glands
• D. Glucagon
• E. Aldosterone

Explanation: Androgens, with testosterone being the primary one, are responsible for the development of secondary sexual characteristics in males. These characteristics include a deeper voice, growth of facial, axillary, and pubic hair, and increased muscle mass. The other options are hormones that have different functions: Cortisol is involved in stress response, the thyroid gland regulates metabolism, Glucagon controls blood sugar levels, and Aldosterone manages electrolyte and water balance.

Q36. A rope-like structure, which connects embryos to the placenta is called _.

• A. Spinal cord
• B. Umbilical cord✓
• C. Optical fiber
• D. Vocal cord
• E. Spindle fiber

Explanation: The umbilical cord is a vital structure that connects the developing embryo to the placenta, allowing nutrients and oxygen to be delivered from the mother to the embryo and waste products to be removed. The other options are unrelated to this function: the spinal cord is part of the nervous system, optical fibers are used in telecommunications, vocal cords are used for producing sound, and spindle fibers are involved in cell division.

Q37. The strong contractions of uterus muscles are controlled by a hormone called _.

• A. Cortisol
• B. Progesterone
• C. Insulin
• D. Testosterone
• E. Oxytocin✓

Explanation: Oxytocin is the hormone responsible for stimulating strong contractions of the uterus during childbirth. It also promotes the production of prostaglandins, which further enhance these contractions. In contrast, cortisol is involved in stress response, progesterone helps maintain pregnancy, insulin regulates blood sugar levels, and testosterone is related to male characteristics. None of these hormones directly control uterine contractions during labor.

Q38. Which one is not the component of the nucleotide of DNA?

• A. H3PO4
• B. Sugar (Deoxyribose)
• C. N - bases
• D. Sugar (ribose)✓
• E. None of these options

Explanation: The correct answer is Sugar (ribose). DNA nucleotides contain deoxyribose sugar, not ribose. Ribose is found in RNA nucleotides. The other components listed, such as H3PO4 (phosphate group), deoxyribose, and nitrogenous bases, are all components of DNA nucleotides.

Q39. “Crossing over” takes place in _ stage.

• A. Leptotene
• B. Zygotene
• C. Diplotene
• D. Pachytene✓
• E. Diakinesis

Explanation: The correct answer is Pachytene. During this stage of meiosis, homologous chromosomes are fully paired, and genetic material is exchanged between non-sister chromatids through a process called 'crossing over,' resulting in increased genetic diversity. Chiasmata are formed at the sites of crossover. In Leptotene, chromosomes are just beginning to condense. In Zygotene, synapsis begins but no crossover occurs. During Diplotene, the synaptonemal complex dissolves, and chiasmata become visible as chromosomes begin to separate. Finally, in Diakinesis, chromosomes are fully condensed and prepared for separation, with chiasmata still present but no new crossing over occurs.

Q40. The hemoglobin of a person with sickle-cell anemia differs from normal molecules of hemoglobin by one:

• A. Monosaccharide, fructose
• B. Disaccharide, sucrose
• C. Fatty acid, glutamic acid
• D. Lipid, oleic acid
• E. Amino acid, valine✓

Explanation: The correct answer is Option E. In sickle-cell anemia, the hemoglobin molecule has a single amino acid substitution where valine is replaced for glutamic acid at the sixth position of the beta chain. This substitution causes hemoglobin molecules to stick together, forming rigid structures that distort red blood cells into a sickle shape. This change results in the reduced ability of red blood cells to transport oxygen efficiently. The other options mention various molecules and acids that are unrelated to the protein structure of hemoglobin and the specific mutation that characterizes sickle-cell anemia.

Q41. For a reaction: H2 + I2 ⇌ 2HI, there will be no effect on equilibrium, if:

• A. Temperature is lowered
• B. Concentration of the reactants is raised
• C. Pressure is lowered✓
• D. Temperature is raised
• E. Concentration of the product is raised

Explanation: The correct answer is C: Pressure is lowered. According to Le Chatelier's Principle, a change in pressure affects equilibrium only if there is a difference in the number of moles of gas on either side of the reaction. In this case, the reaction H2 + I2 ⇌ 2HI involves 2 moles of gas on both sides, so changing the pressure has no effect on the equilibrium position.Lowering or raising the temperature (options A and D) can shift the equilibrium position depending on whether the reaction is exothermic or endothermic. Changing the concentration of reactants or products (options B and E) will also shift the equilibrium to counteract the change, in accordance with Le Chatelier's Principle.

Q42. PCl5 ⇌ PCl3 + Cl2, the number of moles of Cl2 produced will be _? If one mole of PCl5 is heated at 250 C in a vessel having a capacity of 10 dm3 . At 250 C, Kc = 0.041.

• A. 0.041 moles
• B. 0.465 moles✓
• C. 4.65 moles
• D. 4.1 moles
• E. 46.5 moles

Explanation: To find the number of moles of Cl2 produced, we use the equilibrium constant expression: Kc = [PCl3][Cl2]/[PCl5]. Assume x moles of Cl2 are produced. At equilibrium, the concentration of Cl2 and PCl3 will be x/10, and of PCl5 will be (1-x)/10. Substituting these in the expression, we get 0.041 = (x/10)(x/10)/((1-x)/10), solving this gives x = 0.465 moles. Therefore, the correct answer is 0.465 moles. Other options are incorrect as they don't satisfy the equation derived from the equilibrium constant.

Q43. The end point of an acid-base titration is often detected by means of a/an _.

• A. Catalyst
• B. Flame
• C. PH paper
• D. Litmus paper
• E. Indicator✓

Explanation: The correct answer is 'Indicator.' In an acid-base titration, an indicator is used to show the end point of the reaction, usually through a color change. This color change signifies that the amount of acid equals the amount of base in the solution. Other options such as catalyst, flame, pH paper, and litmus paper do not serve this specific purpose. Catalysts and flames are not used for detection, while pH paper and litmus paper are not precise enough for identifying the exact end point in a titration.

Q44. The pH of 0.004 mol dm3 HCl fully dissociated at 25 C will be:

• A. 4 x 10-3
• B. 1
• C. 24
• D. 2.40✓
• E. 0.60

Explanation: The pH of a solution is determined by the negative logarithm of the hydrogen ion concentration: pH = -log[H+]. Here, the concentration of HCl is 0.004 mol dm-3. Since HCl fully dissociates in water, the concentration of H+ ions is also 0.004 mol dm-3. Therefore, the pH is calculated as -log(0.004), which equals 2.40.Option A (4 x 10-3) is the concentration itself, not the pH. Option B (1) and Option E (0.60) suggest a much higher concentration of HCl. Option C (24) is outside the normal pH scale.

Q45. The number of atoms in 9.2 g of Na will be:

• A. 6.02 x 1023 atoms
• B. 2.408 x 1023 atoms✓
• C. 9.2 x 1023 atoms
• D. 23 atoms
• E. 9.2 atoms

Explanation: To find the number of atoms in 9.2 g of Na, first calculate the number of moles of Na. The atomic mass of sodium (Na) is approximately 23 g/mol. Thus, the number of moles in 9.2 g of Na is 9.2 g / 23 g/mol = 0.4 moles. Since one mole of any substance contains Avogadro's number of atoms, which is 6.02 x 1023 atoms/mole, multiplying 0.4 moles by 6.02 x 1023 atoms/mole gives 2.408 x 1023 atoms. Therefore, Option B is correct. The other options are incorrect as they misinterpret the relationship between mass, moles, and atomic number.

Q46. PV = K represents:

• A. Boyle’s Law✓
• B. Avogadro’s Law
• C. Charles’s Law
• D. Graham’s Law
• E. Dalton’s Law

Explanation: Boyle’s Law describes the inverse relationship between pressure and volume of a gas at constant temperature, which is mathematically represented as PV = K. This means as the pressure increases, the volume decreases, and vice versa, while temperature remains constant. Avogadro’s Law involves the relationship between gas volume and moles, Charles’s Law involves volume and temperature, Dalton’s Law involves partial pressures, and Graham’s Law involves the rates of diffusion, none of which are represented by PV = K.

Q47. What volume does a 400 cm3 sample of a gas at 700 torr occupy when the pressure is changed to 2 atm?

• A. 140000 cm3
• B. 184 cm3✓
• C. 0.0184 cm3
• D. 140 cm3
• E. 0.00184 cm3

Explanation: To solve this problem, use the formula for Boyle's Law: P1V1 = P2V2, where P is the pressure and V is the volume. First, convert all pressure units to the same system. Here, 2 atm = 1520 torr. Use the equation (700 torr)(400 cm3) = (1520 torr)(V2). Solve for V2 to find that V2 = 184 cm3. Therefore, the correct answer is 184 cm3. All other options result from incorrect calculations or unit conversions.

Q48. “In an atom no two electrons can have the same set of four quantum numbers.” This statement is commonly known as:

• A. Heisenberg’s Uncertainty Principle
• B. Pauli’s Exclusion Principle✓
• C. Aufbau Principle
• D. Hund’s Rule
• E. (n+l) Rule

Explanation: The correct answer is Pauli’s Exclusion Principle. This principle asserts that no two electrons in the same atom can possess an identical set of four quantum numbers (n, l, ml, ms). This restriction ensures that electrons within an atom are uniquely identified by their quantum states. In contrast, Heisenberg’s Uncertainty Principle relates to the limits of measuring certain pairs of physical properties simultaneously, Aufbau Principle describes the sequence of orbital filling, Hund’s Rule addresses the distribution of electrons in degenerate orbitals, and the (n+l) Rule is used to determine the order of filling orbitals based on their energy levels. None of these principles directly relate to the uniqueness of quantum numbers for electrons in an atom.

Q49. The geometry of BF3 molecule is:

• A. Tetrahedral
• B. Linear
• C. Octahedral
• D. Planar trigonal✓
• E. Square planar

Explanation: The correct answer is that the BF3 molecule has a planar trigonal geometry. This is because the central boron atom forms three bonds with fluorine atoms, and there are no lone pairs on the boron atom. This arrangement leads to a 120-degree angle between the bonds, creating a planar triangular shape. Other options such as tetrahedral, linear, octahedral, and square planar do not fit the molecular structure of BF3 because they involve different numbers and arrangements of surrounding atoms and lone pairs.

Q50. Complete the following equation:4Be9 + 2He4 → ? + 0n1

• A. 6C12✓
• B. 6C14
• C. 7N14
• D. 8O16
• E. 11Na23

Explanation: The correct answer is 6C12 because it conserves both the atomic number (4 from Be + 2 from He = 6 for C) and the mass number (9 from Be + 4 from He = 13, and 12 from C + 1 from n = 13). The other options fail to maintain this balance, either exceeding or falling short of the correct atomic and mass numbers.

Q51. 1s2, 2s2, 2p6, 3s2 ,3p5 is an electronic configuration of:

• A. Na
• B. K
• C. Cl✓
• D. I
• E. S

Explanation: The electronic configuration provided is 1s2 2s2 2p6 3s2 3p5, which totals to 17 electrons. This matches the atomic number of chlorine (Cl), making it the correct answer. Sodium (Na) has only 11 electrons, potassium (K) has 19 electrons, iodine (I) has 53 electrons, and sulfur (S) has 16 electrons. Thus, none of these match the given configuration.

Q52. The average rate of a chemical reaction can be expressed as the:

• A. Concentration of reactants minus the concentration of products
• B. Concentration of products and reactants multiplied by the time required for the reaction
• C. Change in concentration of products or reactants divided by the change in time✓
• D. Change in time divided by change in concentration of products or reactants

Explanation: The correct answer is that the average rate of a chemical reaction is expressed as the change in concentration of products or reactants divided by the change in time. This definition reflects how quickly a reaction progresses. Option C correctly captures this relationship. Option A describes a concentration difference without considering time, Option B incorrectly proposes multiplying concentrations and time, and Option D inverts the correct relationship, making it incorrect.

Q53. The amount of heat (qv) at constant volume is equal to

• A. Change in internal energy (ΔE)✓
• B. Change in enthalpy (ΔH)
• C. Ideal gas constant
• D. PΔV
• E. Pressure (P)

Explanation: At constant volume, the relationship between heat (ΔQ), internal energy (ΔU), and work (W) is given by the first law of thermodynamics: ΔQ = ΔU + W. Since work done on a system at constant volume is zero (W = PΔV = 0), the equation simplifies to ΔQ = ΔU. Therefore, the heat added to the system at constant volume is equal to the change in internal energy.Option A is correct because it accurately reflects this relationship. Option B is incorrect because ΔH is associated with constant pressure, not volume. Options C, D, and E are unrelated to the concept of heat transfer at constant volume.

Q54. The color of transition metal complex ions is due to _.

• A. Splitting of d-orbitals✓
• B. Impurities
• C. Adsorption
• D. Loss of electrons
• E. Formation of new bonds

Explanation: The color of transition metal complex ions is primarily due to the splitting of d orbitals in a process called crystal field splitting. When light is absorbed, electrons are excited from a lower-energy d orbital to a higher-energy d orbital, resulting in a d–d transition. This absorption of light at specific wavelengths gives rise to the characteristic colors. Other factors such as impurities, adsorption, electron loss, and bond formation can influence color but are not the primary cause in transition metal complexes. Incorrect options like impurities, adsorption, electron loss, and bond formation do not directly explain the color in this context.

Q55. When methylbenzene is treated with bromine in the presence of a catalyst, a mixture of two monobromo isomers is formed. What are the structures of these two isomers?

• A. Ortho-bromotoluene and meta-bromotoluene
• B. Meta-bromotoluene and para-bromotoluene
• C. Ortho-bromotoluene and para-bromotoluene✓
• D. Ortho-bromotoluene and ortho-bromotoluene
• E. Para-bromotoluene and para-bromotoluene

Explanation: The correct answer is Ortho-bromotoluene and para-bromotoluene. The methyl group (-CH3) on the benzene ring acts as an ortho-para directing group, meaning it directs incoming substituents (like bromine in this case) to the ortho (positions 2 and 6) and para (position 4) positions on the ring. Thus, when methylbenzene (toluene) is treated with bromine in the presence of a catalyst, bromine substitutes at these positions, forming ortho-bromotoluene and para-bromotoluene as the two monobromo isomers.Other options are incorrect because they either suggest meta substitution, which is not favored by the -CH3 group, or imply duplication of the same isomer, which does not align with the formation of two distinct isomers.

Q56. The crystals of CuSO4 . 5H2O are:

• A. Colorless
• B. Blue✓
• C. Yellow
• D. Green
• E. Crimson red

Explanation: Copper(II) sulfate pentahydrate is well-known for its bright blue crystalline form. This color is due to the water molecules in the crystal lattice which affect the light absorption of the copper ions. Other options like colorless, yellow, green, and crimson red are incorrect as they do not match the characteristic color of copper(II) sulfate pentahydrate. For example, a colorless appearance would suggest the absence of hydration, while yellow and green are typical of other metal compounds.

Q57. Tetraethyl leads (Pb(C2H5)4 ) is used as _ in gasoline.

• A. Purifier
• B. Knock inhibitor✓
• C. Preservative
• D. Catalyst
• E. Propellant

Explanation: Tetraethyl lead (Pb(C2H5)4) is used as an anti-knock agent or knock inhibitor in gasoline. Its primary function is to reduce engine knocking, which allows the engine to run more smoothly and efficiently. By raising the temperature and pressure at which auto-ignition occurs, it increases the fuel's octane rating, optimizing engine performance. The other options are incorrect as they do not describe the function of tetraethyl lead: it is not used to purify, preserve, catalyze, or propel gasoline.

Q58. The polymerization of three acetylene molecules in the presence of organo nickel yields _.

• A. Vinyl acetylene
• B. Ethane
• C. Cyclohexane
• D. Plastic
• E. Benzene✓

Explanation: The polymerization of three acetylene molecules in the presence of organo nickel catalysts results in the formation of benzene. This process is known as trimerization, where three molecules of acetylene (C2H2) combine to form a benzene ring (C6H6). This specific reaction highlights the ability of acetylene to form aromatic compounds under the right conditions.Other options such as vinyl acetylene, ethane, cyclohexane, and plastic do not accurately describe the outcome of this particular reaction. Vinyl acetylene might be related to polymerization in some contexts, but not in this specific scenario. Ethane and cyclohexane do not relate to this reaction, and 'plastic' is too broad and generic to be correct.

Q59. All of the following are electrophilic substitution reactions of benzene except:

• A. Halogenation
• B. Nitration
• C. Sulphonation
• D. Alkylation
• E. Hydrogenation✓

Explanation: Hydrogenation of benzene is not an electrophilic substitution reaction. Instead, it is an electrophilic addition process where hydrogen is added to the double bonds of benzene, converting it into cyclohexane. In contrast, halogenation, nitration, sulphonation, and alkylation all involve the substitution of a hydrogen atom on the benzene ring with another group, making them electrophilic substitution reactions.

Q60. The given structure is an example of

• A. Primary propyl alcohol
• B. Secondary butyl alcohol
• C. Tertiary butyl alcohol✓
• D. Quaternary alcohol
• E. none of these

Explanation: The correct answer is Tertiary butyl alcohol. In the structure, the hydroxyl group (-OH) is bonded to a carbon atom that is connected to three other carbon atoms, characteristic of tertiary alcohols. The term 'butyl' indicates a four-carbon chain, which aligns with the structure.Option A is incorrect because primary alcohols have the hydroxyl group attached to a carbon atom connected to only one other carbon atom. Option B is incorrect because secondary alcohols have the hydroxyl group on a carbon atom connected to two other carbon atoms. Option D is incorrect as quaternary alcohols do not exist; a quaternary carbon cannot form a bond with a hydroxyl group. Option E is incorrect because the structure corresponds to one of the given options.

Q61. SN2 reactions are:

• A. Two steps bimolecular nucleophilic substitution reaction
• B. One step bimolecular nucleophilic substitution reaction✓
• C. Two steps unimolecular nucleophilic substitution reaction
• D. One step unimolecular nucleophilic substitution reaction
• E. Elimination reaction

Explanation: The correct answer is B - one step bimolecular nucleophilic substitution reaction. In SN2 reactions, 'SN' stands for nucleophilic substitution and '2' refers to the bimolecular nature, meaning two molecules are involved in the rate-determining step. These reactions are concerted, meaning the nucleophile's attack and the leaving group's departure occur simultaneously in a single step. Option A is incorrect because SN2 reactions do not involve two steps. Option C is wrong since SN2 is not unimolecular. Option D is incorrect as SN2 involves two species, not one. Option E is irrelevant as elimination reactions differ from substitution reactions.

Q62. The general formula of ester is:

• A. R-CHO
• B. R-O-R
• C. R-COOH
• D. R-X
• E. R-COOR✓

Explanation: The correct answer is R-COOR. Esters are characterized by the presence of a carbonyl group (C=O) adjacent to an ether linkage (O-R). The general formula for an ester is R-COOR′, where R is an alkyl or aryl group, and R′ is also an alkyl or aryl group but not a hydrogen atom. If R′ were a hydrogen atom, the compound would instead be a carboxylic acid. The other options represent different organic compounds: R-CHO is an aldehyde, R-O-R is an ether, R-COOH is a carboxylic acid, and R-X is a halide.

Q63. A dipolar charged but over all electrically neutral ion is called _.

• A. Positive ion
• B. Negative ion
• C. Zwitterion✓
• D. Ion
• E. Polar molecule

Explanation: A zwitterion is a unique type of molecule that contains both positive and negative charges but is overall electrically neutral. This occurs because the charges are localized at different parts of the molecule, balancing each other out. For example, amino acids in their isoelectric point form zwitterions. The other options are incorrect because:Positive ion: These are cations with a net positive charge, not neutral.Negative ion: These are anions with a net negative charge, not neutral.Ion: This term generally refers to charged species, which may not be neutral.Polar molecule: While polar molecules have charge separation, they are not considered zwitterions as they do not have full charges localized within the molecule.

Q64. What is the correct IUPAC name of an organic compound with the molecular formula CH3CH2COOH?

• A. Methanoic acid
• B. Ethanoic acid
• C. Propanoic acid✓
• D. Butanoic acid
• E. Pentanoic acid

Explanation: The IUPAC name for the organic compound CH3CH2COOH is Propanoic acid. This is because it has a three-carbon chain, indicated by the prefix 'prop-', and contains a carboxylic acid functional group (-COOH). Methanoic acid, Ethanoic acid, Butanoic acid, and Pentanoic acid have different numbers of carbon atoms in their main chains, making them incorrect for this particular molecular formula.

Q65. For a chemical A → B, the threshold energy of reaction is 51 K.J/mol. The average internal energy of A is 27 K.J/mol. Calculate the activation energy of A?

• A. 19 K.J/mol
• B. 24 K.J/mol✓
• C. 30 K.J/mol
• D. 34 K.J/mol
• E. 37 K.J/mol

Explanation: The threshold energy for the reaction A → B is 51 K.J/mol, which is the minimum energy needed for the reaction to take place. The reactant A has an initial internal energy of 27 K.J/mol. The activation energy is the additional energy required to reach the threshold energy from the current energy level of A. Therefore, the activation energy is calculated by subtracting the internal energy from the threshold energy: 51 K.J/mol - 27 K.J/mol = 24 K.J/mol. Hence, the correct answer is 24 K.J/mol.Other options are incorrect because they either underestimate or overestimate the energy needed, failing to accurately subtract the internal energy from the threshold energy.

Q66. CaH2 is an example of:

• A. Ionic hydride✓
• B. Covalent hydride
• C. Complex hydride
• D. Borderline hydride
• E. Polymeric hydride

Explanation: CaH2 is an ionic hydride because it consists of calcium, a metal, forming an ionic bond with hydrogen. The metal donates electrons to hydrogen, resulting in the formation of Ca2+ and H- ions. This characteristic distinguishes ionic hydrides from covalent hydrides, which involve non-metals. Complex hydrides are defined by the presence of complex anions, which is not the case for CaH2. Borderline hydrides are typically associated with elements from groups 11 and 12, not calcium. Lastly, polymeric hydrides involve polymeric structures, unlike the simple ionic structure of CaH2.

Q67. The formula of bleaching powder is:

• A. 2CaSO4.2H2O
• B. (CaSO4)2 . H2O
• C. Ca(OCl)Cl✓
• D. MgSO4.7H2O
• E. none of these

Explanation: The correct formula for bleaching powder is Ca(OCl)Cl, which is known as calcium oxychloride. It is commonly used in water treatment and as a disinfectant. The other options are incorrect as they represent various other compounds: Option A, 2CaSO4.2H2O, is gypsum; Option B, (CaSO4)2 . H2O, is plaster of Paris; Option D, MgSO4.7H2O, is Epsom salt. Option E, 'none of these', is incorrect because the correct answer is provided in option C.

Q68. The d block elements are also called as:

• A. Inner transition elements
• B. Outer transition elements✓
• C. Alkali metals
• D. Alkaline earth metals
• E. Halogens

Explanation: The d-block elements are known as outer transition elements because they occupy the central section of the periodic table and possess partially filled d orbitals. This differentiates them from the f-block elements, which are referred to as inner transition elements due to their position in the lanthanide and actinide series. Alkali metals, alkaline earth metals, and halogens are located in different groups and have distinct properties not associated with the d-block elements.

Q69. Aqua regia (Royal water) is used as a solvent for:l

• A. Alkali metals
• B. Halogens
• C. Oxygen family
• D. Boron family
• E. Gold and noble metals✓

Explanation: Aqua regia, a mixture of concentrated nitric acid and hydrochloric acid, is known for its ability to dissolve noble metals, particularly gold and platinum. This property arises because the mixture provides both a source of chloride ions and an oxidizing environment, which together break down the stable surface of these metals. The other options, including alkali metals, halogens, the oxygen family, and the boron family, do not require such a powerful solvent as they either react with other chemicals or do not dissolve in acidic mixtures.

Q70. Silver mirror is formed in

• A. Tollen’s Test✓
• B. Fehling Test
• C. Baeyer’s Test
• D. Cannizzaro Reaction
• E. Grignard reagent

Explanation: Tollens' test, also known as silver-mirror test, is a qualitative laboratory test used to distinguish between an aldehyde and a ketone. It exploits the fact that aldehydes are readily oxidized (see oxidation), whereas ketones are not

Q71. The operations of a transistor requires:

• A. That the emitter be heated
• B. That the base be heated
• C. That the collector be heated
• D. That the collector be enclosed in a vacuum
• E. None of these✓

Explanation: Transistors are solid-state devices that operate through semiconductor materials, and they do not require heating or vacuum conditions. None of the options provided correctly describe a requirement for their operation. Heating the emitter, base, or collector is not necessary, and while some electronic devices like vacuum tubes require a vacuum, transistors do not. Therefore, the correct answer is 'None of these.'

Q72. The conversion of photon into electron - positron pair is called

• A. Compton effect
• B. Photoelectric effect
• C. Pair production✓
• D. Annihilation of matter
• E. Synthesis

Explanation: The correct answer is Pair Production. This process involves the conversion of a photon into an electron-positron pair, typically occurring near an atomic nucleus to conserve momentum. The other options describe different phenomena: the Compton effect involves scattering, the photoelectric effect involves electron emission from a material, annihilation of matter involves particle-antiparticle collisions, and synthesis is not related to subatomic particle interactions.

Q73. According to Bohr’s model for the hydrogen atom:The total energy of an electron remains constant as long as it remains in the same orbit.The total energy of the electron remains constant as it jumps into the other orbit.The total energy of an electron keeps on changing as long as it remains in the same orbit.

• A. I only✓
• B. II only
• C. III only
• D. I or III only
• E. I, II and III

Explanation: According to Bohr's model for the hydrogen atom, the total energy of an electron remains constant as long as it stays in the same orbit (Statement I). When an electron transitions between orbits, it absorbs or emits energy as photons, corresponding to the difference in energy levels between the orbits. Therefore, statement II is incorrect as the electron's energy does not remain constant when it jumps to another orbit. Similarly, statement III is incorrect because the energy of an electron does not change while it is in the same orbit.

Q74. The atoms of same element with same atomic numbers but different atomic masses are called:

• A. Metals
• B. Isotopes✓
• C. Isomorphs
• D. Isobars
• E. Non-metals

Explanation: Isotopes are atoms of the same element that have identical atomic numbers but differ in their atomic masses due to varying numbers of neutrons. This is the defining characteristic of isotopes. In contrast, isobars are elements with the same mass number but different atomic numbers. Metals and non-metals are broad categories based on physical and chemical properties, and isomorphs relate to the crystal structure of compounds, not atomic variations.

Q75. Neutrons penetrate matter readily chiefly because they:

• A. Occupy no more than one tenth of the volume of electrons
• B. Occupy no more than one tenth of the volume of protons
• C. Have a smaller mass than protons
• D. Are electrically neutral✓
• E. Are needlike in shape

Explanation: Neutrons are able to penetrate matter readily because they are electrically neutral. This neutrality means they are not affected by the electric fields within atoms, unlike charged particles such as electrons or protons. As a result, they can pass through matter without being deflected or absorbed. Other options, such as comparisons of volume, mass, or shape, do not accurately contribute to the neutrons' penetrative ability because these characteristics are not as influential as their lack of charge.

Q76. Efficiency of a Carnot engine working between 150˚C and 25˚C is:

• A. 50%
• B. 100%
• C. 23.6%
• D. 29.4%✓
• E. 98%

Explanation: The efficiency of a Carnot engine is calculated using the formula: E = 1 - (T2/T1), where T1 and T2 are the temperatures of the hot and cold reservoirs, respectively, in Kelvin. To convert Celsius to Kelvin, add 273.15 to the Celsius temperature. For this question: T1 = 150˚C + 273.15 = 423.15K T2 = 25˚C + 273.15 = 298.15K. Therefore, E = 1 - (298.15/423.15) = 0.304 or 29.4%. Option A (50%) is incorrect because it results from a miscalculation or misunderstanding of the formula. Option B (100%) is not feasible for a Carnot engine under practical conditions. Option C (23.6%) is incorrect as it does not follow the correct application of the formula. Option D (29.4%) is correct as it accurately represents the calculated efficiency. Option E (98%) is far too high and does not align with the calculated values.

Q77. In an isobaric process:

• A. Pressure is constant✓
• B. Volume is constant
• C. Temperature is constant
• D. No heat enters or leaves the system
• E. None of the given options

Explanation: An isobaric process is defined by constant pressure throughout the process. The prefix 'iso-' means constant, and '-baric' relates to pressure, so together they describe a process where the pressure does not change. Option A is correct because it directly identifies this characteristic. Option B incorrectly refers to a process with constant volume, which is actually 'isochoric'. Option C suggests constant temperature, known as 'isothermal'. Option D describes an adiabatic process, where no heat exchange occurs, which is unrelated to isobaric processes. Lastly, option E is incorrect because option A accurately describes the isobaric condition.

Q78. proton is placed midway between two parallel metallic plates which are 0.2 meters apart. The plates are connected to a 80V battery. It’s electric intensity will be:

• A. 400 N/C✓
• B. 700 N/C
• C. 800 N/C
• D. 900 N/C
• E. 600 N/C

Explanation: The electric field (E) between two parallel plates is given by the formula E = V/d, where V is the voltage across the plates and d is the separation between them. In this problem, V = 80V and d = 0.2 meters. Substituting these values into the formula gives E = 80 / 0.2 = 400 N/C, making Option A correct.Other options provide incorrect electric field values based on incorrect calculations or assumptions about voltage and distance. Always ensure to substitute the correct values into the formula for accurate results.

Q79. The number is electric lines of force passing through a surface is called:

• A. Electron volt
• B. Magnetic flux
• C. Electric flux✓
• D. Capacitor
• E. Charge

Explanation: The correct answer is Electric flux, which is a measure of the number of electric field lines passing through a given surface. It's calculated using the formula ϕ=E . This concept is specific to electric fields. The other options are incorrect: Electron volt is a unit of energy, Magnetic flux pertains to magnetic fields, Capacitor is a component used to store charge, and Charge is a property of matter, not a measure of field lines.

Q80. KWh equals to:

• A. 36 x 105 Joules✓
• B. 360 x 105 Joules
• C. 0.36 x 105 Joules
• D. 0.036 x 105 Joules
• E. 360 Joules

Explanation: 1 kilowatt hour (kWh) is a measure of energy that equates to the energy consumed by a 1 kilowatt (kW) power source operating for 1 hour. Mathematically, this is calculated as:1 kWh = 1 kW × 1 hour = 1000 watts × 3600 seconds = 3.6 x 106 Joules or 36 x 105 Joules.Option A correctly reflects this conversion. Options B, C, D, and E are incorrect because they do not match this calculation. Option B scales the energy by an incorrect factor, while options C, D, and E represent values that are significantly smaller than the correct energy amount.

Q81. The Ohm’s Law relates _ and _.

• A. Charge … time
• B. Energy … charge
• C. Voltage … current✓
• D. Distance … charge
• E. Resistance … length

Explanation: Ohm's Law is a fundamental principle in electronics and electrical engineering that relates the voltage (V), current (I), and resistance (R) in an electrical circuit. The law is represented by the equation V = IR, where voltage is the product of current and resistance. Hence, Ohm's Law directly relates voltage and current. The other options are incorrect because they refer to different concepts that do not directly pertain to Ohm's Law. For example, 'Charge … time' refers to the definition of current, while 'Resistance … length' relates to the physical properties of conductors, not directly to Ohm's Law.

Q82. A 3-cm length of wire is moved at right angles across a uniform magnetic field with a speed of 2.0 m/s . If the flux density is 5.0 teslas, what is the magnitude of the induced e.m.f?

• A. 0.03 V
• B. 0.3 V✓
• C. 0.6 V
• D. 10 V
• E. 20 V

Explanation: E=BVLE=5*2*0.03E=0.3V

Q83. When a transformer is connected to 120-volt ac, it supplies 3000 V to a device. The current through the secondary winding then is o.06 A and the current through the primary is 2 A. The number of turns in the primary winding is 400. The number of turns in the secondary winding is:

• A. 16
• B. 30
• C. 1000
• D. 2000
• E. 10000✓

Explanation: Turns(primary)/V(primary)=Turns(secondary)/V(secondary)400 turns / 120 V = X turns / 3000 VX = 3000 * 400 / 120 = 10,000 turns

Q84. The Ammeter is used to measure:

• A. current✓
• B. power
• C. voltage
• D. unknown resistance
• E. Pressure

Explanation: The correct answer is 'current'. An ammeter is a device used to measure the flow of electric current in a circuit. It is connected in series with the circuit whose current you wish to measure. Other options such as 'power', 'voltage', 'unknown resistance', and 'pressure' are incorrect because they are measured by different devices or methods: power is calculated, voltage is measured by a voltmeter, resistance by an ohmmeter, and pressure by devices like barometers.

Q85. Galvanometer works on the principle of:

• A. Magnetic torque✓
• B. Ohm’s Law
• C. Pascal’s Law
• D. Boyle’s Law
• E. Coulomb's Law

Explanation: A galvanometer operates on the principle of magnetic torque. When a current flows through a coil situated in a magnetic field, the interaction between the magnetic field and the current results in a torque that causes the coil to rotate. The deflection of the coil is directly proportional to the current, thus allowing the measurement of current intensity. This differs from Ohm’s Law, which relates voltage and current in a circuit, and from Pascal’s, Boyle’s, and Coulomb’s Laws, which deal with fluid mechanics, gas laws, and electrostatic forces, respectively, none of which involve the magnetic principles utilized in a galvanometer.

Q86. The maximum distance in horizontal direction of a projectile is called:

• A. Range✓
• B. Height
• C. Trajectory
• D. Position
• E. Length

Explanation: The maximum horizontal distance a projectile covers from its launch point to the point it lands is called the range. This is a key concept in physics that helps us understand projectile motion. The other options are incorrect as they refer to different aspects of projectile motion: Height is the maximum vertical distance, Trajectory is the entire path of the projectile, Position is a specific point on that path, and Length is a generic term not specific to projectile motion.

Q87. The vertical component of acceleration of a projectile:

• A. Is less than the gravitational acceleration
• B. Is equal to the gravitational acceleration✓
• C. Is more than the gravitational acceleration
• D. Has no relation with the gravitational acceleration

Explanation: The vertical component of acceleration of a projectile is solely determined by gravity, providing a constant acceleration of approximately 9.8 m/s² downward. This means that the vertical acceleration is always equal to the gravitational acceleration, as stated in Option B. Options A and C are incorrect as they suggest variations in acceleration beyond the influence of gravity. Option D is incorrect because it disregards the significant impact of gravity on the vertical motion of a projectile.

Q88. Torque depends on:

• A. Force and speed
• B. Force and moment arm✓
• C. Velocity and time
• D. Force and time
• E. Displacement and force

Explanation: Torque, often referred to as rotational force, is the measure of the tendency of a force to rotate an object about an axis, fulcrum, or pivot. It is calculated as the product of the force and the moment arm, which is the perpendicular distance from the axis of rotation to the line of action of the force. Thus, the correct answer is Force and moment arm. Other factors such as speed, velocity, time, and displacement are not involved in the calculation of torque. Speed and velocity describe motion, time refers to duration, and displacement is a measure of change in position, none of which are required to determine torque.

Q89. Jumping of paratroops from helicopters is an example of _ equilibrium.

• A. static
• B. neutral
• C. dynamic✓
• D. unstable
• E. none of these

Explanation: When paratroopers jump from helicopters, they initially accelerate due to gravity. However, once air resistance builds up and balances the gravitational force, they stop accelerating and fall at a constant velocity. This state, where forces are balanced but motion continues, is called dynamic equilibrium. Other options like static and neutral equilibrium imply either no motion or different types of balance that don't apply to this scenario, while unstable equilibrium suggests a propensity to move away from equilibrium upon disturbance, which is not the case here.

Q90. The average density of earth is:

• A. 5.98 x 1024 kg/m3
• B. 6.67 x 10-11 kg/m3
• C. 5.5 x 103 kg/m3✓
• D. 6.38 x 108 kg/m3
• E. 8.096 x 106 kg/m3

Explanation: The average density of Earth is approximately 5.5 x 103 kg/m3. This value is derived from the mass and volume of the Earth and is crucial for understanding its structure and geophysical properties. Option A refers to the mass of the Earth, Option B is the gravitational constant, and Options D and E are arbitrary values not related to Earth's average density.

Q91. 1 British Thermal Unit = _ Joules

• A. 564
• B. 684
• C. 1000
• D. 1055✓
• E. 769

Explanation: The correct answer is 1055 Joules. The British Thermal Unit (BTU) is a traditional unit of heat; it is approximately equal to 1055 Joules. This conversion is important in fields involving energy calculations. Options A (564), B (684), C (1000), and E (769) are incorrect as they do not match the standard conversion factor of 1 BTU to Joules.

Q92. Fossil fuels include:

• A. Atom
• B. Sup
• C. Water
• D. Coal, gas, crude oil✓
• E. Wind

Explanation: The correct answer is Coal, gas, crude oil. Fossil fuels are formed from the remains of ancient plants and animals, making them carbon-rich and suitable for energy production. Coal, natural gas, and crude oil are the primary types of fossil fuels used globally to generate electricity and power vehicles. The other options are incorrect: 'Atom' refers to the smallest unit of matter, 'Sup' appears to be unrelated, 'Water' is used for hydroelectric power but is not a fossil fuel, and 'Wind' is a renewable energy source.

Q93. Newton’s rings may be observed if you place a curved glass surface on a flat grass surface. A thin film of air is wedged between the glass surface. Looking down, one can see several rings around the point where the two glass surfaces touch. Newton’s rings are produced by:

• A. Interference✓
• B. Diffraction
• C. Polarization
• D. Absorption
• E. Shadows

Explanation: Newton's rings occur due to the interference of light waves reflected between a spherical glass surface and a flat glass surface. The varying thickness of the air film between the surfaces creates constructive and destructive interference, leading to alternating bright and dark rings. Diffraction, on the other hand, involves the bending of light around obstacles and does not create the concentric ring pattern. Polarization involves the alignment of light waves, unrelated to the pattern formation. Absorption refers to the uptake of light energy by a material and does not produce visible rings. Lastly, shadows are simply areas where light is obstructed, not patterns of interference.

Q94. An object is placed at a distance of 60 cm from a concave lens of focal length 30 cm, position of image will be:

• A. 20 cm✓
• B. -20 cm
• C. 60 cm
• D. 30 cm
• E. 15 cm

Explanation: To determine the position of the image formed by a concave lens, use the lens formula: \(\frac{1}{f} = \frac{1}{v} - \frac{1}{u}\), where \(f\) is the focal length, \(v\) is the image distance, and \(u\) is the object distance. For a concave lens, the focal length is negative, so \(f = -30\) cm and \(u = -60\) cm (since the object is on the same side as the lens). Plugging in these values: \(\frac{1}{-30} = \frac{1}{v} - \frac{1}{-60}\). Solving this equation gives \(v = -20\) cm, indicating the image is 20 cm from the lens on the same side as the object. This matches option A (20 cm). The negative sign in option B (-20 cm) would imply incorrect interpretation of the image's position, as concave lenses form virtual images on the same side as the object.

Q95. The time period of simple pendulum whose length is 88.2 cm will be: (g = 9.8 m/s^2)

• A. 2.5 s
• B. 2 s
• C. 1.884 sec✓
• D. 3 s
• E. 1 s

Explanation: The time period of a simple pendulum is calculated using the formula T = 2π√(l/g), where 'l' is the length of the pendulum and 'g' is the acceleration due to gravity. Given l = 88.2 cm = 0.882 m and g = 9.8 m/s², substituting these values gives T = 2π√(0.882/9.8), which results in a time period of approximately 1.884 seconds. Therefore, the correct answer is option C.Option A (2.5 s) and Option D (3 s) are overestimations of the time period, likely due to incorrect calculations. Option B (2 s) is a close approximation but not precise. Option E (1 s) underestimates the time period, indicating an error in calculation.

Q96. Dimension of volume is:

• A. LT-1
• B. LT-2
• C. L3✓
• D. L2
• E. L4

Explanation: The dimension of volume is L3 because volume is a measure of the space occupied by an object, calculated by multiplying three lengths together, such as in the formula for the volume of a cube, which is length × width × height (L × L × L = L3).Option A (LT-1) is incorrect because it represents a dimension of velocity. Option B (LT-2) is incorrect because it represents a dimension of acceleration. Option D (L2) is incorrect because it represents a dimension of area, and Option E (L4) is incorrect because it does not represent a standard physical quantity.

Q97. The components of vector along x- axis and y-axis are also known as:

• A. Position vectors
• B. Null vectors
• C. Rectangular components✓
• D. Free vectors
• E. Position and negative vectors

Explanation: Vectors in a 2D coordinate system can be broken down into two perpendicular components: one along the x-axis and one along the y-axis. These are called 'rectangular components' or 'Cartesian components' because of their alignment with the axes of a rectangle or Cartesian plane. Other types of vectors, such as position vectors, null vectors, free vectors, and the incorrectly named 'position and negative vectors,' do not specifically describe this breakdown into x and y components. Position vectors locate points in space, null vectors have no magnitude, free vectors can be repositioned in space, and the term 'position and negative vectors' is not standard in vector analysis.

Q98. A is parallel to B then A.B =

• A. zero
• B. AB✓
• C. -AB
• D. A/b
• E. none

Explanation: The dot product of two vectors A and B is given by the formula A·B = |A| |B| cos(θ), where θ is the angle between the vectors. For parallel vectors, θ = 0°. The cosine of 0° is 1, so the dot product simplifies to |A| |B|, or AB.Option A is incorrect because a dot product of zero indicates perpendicular vectors, not parallel ones. Option C is incorrect as it suggests a negative product which would apply if the vectors were anti-parallel. Option D is not a valid mathematical expression for a dot product. Option E is incorrect as the dot product for parallel vectors is not 'none'.

Q99. Momentum is defined as:

• A. Work x time
• B. Mass x acceleration
• C. Mass x velocity✓
• D. Velocity x time
• E. Force x time

Explanation: Momentum is defined as the product of an object's mass and its velocity, represented by the formula: momentum = mass x velocity. This is fundamental in physics as it relates to how much motion an object has. Option C is correct. Option A (Work x time) is unrelated to momentum as work is related to energy transfer. Option B (Mass x acceleration) describes force, not momentum. Option D (Velocity x time) lacks mass, a necessary component for calculating momentum. Lastly, Option E (Force x time) describes impulse, which affects momentum but does not define it.

Q100. Sliding friction is slightly _ the limiting frictionI. more thanII. less thanIII. equal than

• A. I only
• B. II only✓
• C. III only
• D. I or III only
• E. I, II and III

Explanation: The correct answer is II only: 'less than.' Limiting friction is the maximum frictional force that must be overcome to start an object moving. Once the object starts moving, the friction decreases slightly, and this is known as sliding friction. Sliding friction is less than limiting friction because once the object is in motion, the micro-welds or interlocking between surfaces are broken, reducing resistance. Options I and III are incorrect because sliding friction is neither more than nor equal to limiting friction.