Sindh Mcat Nts 2006 — Solved Past Paper with Answers

Q1. Synonym for the word COMPRISE:

• A. Consists of✓
• B. Forms
• C. To agree
• D. Accumulate

Explanation: The word 'comprise' refers to the idea of something being made up of various parts or elements, indicating the structure or constitution of an entity. Therefore, 'consists of' accurately captures this meaning, identifying the parts that make up a whole. 'Forms' suggests the act of creating or establishing, which is not synonymous with 'comprise.' 'To agree' pertains to consensus and opinions, unrelated to structural composition. 'Accumulate' describes a process of gradual gathering, not the parts that constitute a whole.

Q2. The correct antonym for the word Bliss:

• A. Happiness
• B. Misery✓
• C. Comfort
• D. Pleasure

Explanation: Antonyms are words with opposite meanings. Bliss means perfect happiness or joy, while Misery means extreme sadness or unhappiness, making it the correct antonym. The other options such as Happiness, Comfort, and Pleasure are all synonyms of bliss, as they convey similar positive emotions.

Q3. Choose the correct anytonym for EXHIBIT:

• A. Conceal✓
• B. Showy
• C. To sell
• D. Conceive

Explanation: The correct answer is Conceal because 'exhibit' means to show or display something openly. The opposite action would be to hide or keep it secret, which is the meaning of 'conceal'.Option B, Showy, suggests something that stands out but is not the opposite of exhibiting. Option C, To sell, involves a commercial transaction and does not relate to the act of showing or hiding. Option D, Conceive, is about generating ideas and is not an antonym of exhibiting.

Q4. "Inflict pain" on others mean:

• A. To injure
• B. To harness
• C. Feeling pain
• D. Giving pain✓

Explanation: To inflict pain on others means to deliberately cause them to suffer or experience pain. This involves an active effort to make someone else feel pain. The other options do not accurately capture this meaning: 'To injure' implies physical harm but not necessarily the intention to cause pain; 'To harness' is unrelated to pain, focusing instead on control; and 'Feeling pain' refers to experiencing pain personally rather than causing it to others.

Q5. Which is a radioactive Halogen?

• A. I2
• B. Cl2
• C. Br2
• D. None of the above✓

Explanation: Astatine, not listed among the options, is the radioactive halogen. It is the rarest naturally occurring element in the Earth's crust and all its isotopes are radioactive. The other halogens listed (iodine, chlorine, and bromine) are stable and not inherently radioactive. This question tests your knowledge of elemental properties, specifically the unique characteristics of halogens.

Q6. Which has highest K.E amongst following:

• A. H2
• B. O2✓
• C. CH4
• D. All of these

Explanation: O2 is the correct answer because it has a double bond between its atoms, resulting in higher kinetic energy compared to other options with single bonds. The kinetic energy of a molecule is influenced by its bond type and molecular weight. H2 has a single bond and is lighter, resulting in lower energy. CH4 has multiple single bonds, but these are not as energy-intensive as the double bond in O2. Thus, the kinetic energy of O2 is the highest among the given options.

Q7. Which is not a normal cracking phenomenon:

• A. Thermal Cracking
• B. Catalytic Cracking
• C. Steam Cracking
• D. Normal Cracking✓

Explanation: 'Normal Cracking' is not a recognized type of cracking phenomenon. Cracking, in the context of petrochemicals, involves processes like thermal cracking, catalytic cracking, steam cracking, and hydrocracking. These processes are used to break down larger hydrocarbon molecules into smaller ones, typically using heat, catalysts, or steam. The term 'normal cracking' does not refer to any specific method or process in this context, which is why it is the correct answer to the question.Other options provided are well-established methods used in the industry: 'Thermal Cracking', 'Catalytic Cracking', and 'Steam Cracking' are all legitimate and recognized processes used to achieve the breakdown of hydrocarbons.

Q8. What is the property of an oxidising agent?

• A. Electron gainer✓
• B. Electron donor
• C. Negative charge
• D. Loose hydrogen

Explanation: An oxidizing agent, or oxidant, is a substance that gains electrons during a chemical reaction and is reduced in the process. This ability to gain electrons makes it an electron acceptor. It is often in a higher oxidation state because it can accept electrons to reach a lower oxidation state. Option A is correct because an oxidizing agent gains electrons. Option B is incorrect because an electron donor is a reducing agent, which loses electrons. Option C is incorrect as a negative charge pertains to an excess of electrons, not specifically to the role of an oxidizing agent. Option D is incorrect because losing hydrogen is related to oxidation, not a property of an oxidizing agent.

Q9. H2 + Br → 2HBrThe expression rate is: RATE = K[ H2] [Br] 1/2 The order of the reaction is:

• A. 2
• B. 1.5✓
• C. 1
• D. Zero

Explanation: The overall order of a chemical reaction is determined by summing the exponents of the concentration terms in the rate law. Here, the rate law is given as RATE = K[H2][Br]1/2. The exponents are 1 for [H2] and 0.5 for [Br], giving a total reaction order of 1.5.Option A (2) is incorrect because the sum of the exponents does not equal 2. Option C (1) is incorrect because it does not account for the 0.5 exponent of [Br]. Option D (Zero) is incorrect as the reaction clearly depends on the concentration of reactants, as indicated by the non-zero exponents.

Q10. Synonym of the word Loathsome:

• A. Handsome
• B. Unpleasant✓
• C. Brilliant
• D. Compare

Explanation: Synonym means a word or phrase that means exactly or nearly the same as another word or phrase in the same language. Loathsome means causing hatred or disgust,hence the option which fits perfectly with this word is Unpleasant.

Q11. Different Food Chains interact with each other to form:

• A. Food Pyramid
• B. Energy Graph
• C. Food Web✓
• D. Energy Pyramid
• E. Food Chain Complex

Explanation: The correct answer is 'Food Web'. A Food Web is a comprehensive network of interconnected food chains within an ecosystem, showing how various organisms are linked through feeding relationships. It provides a more complete picture of the energy flow and interactions between species compared to a single food chain. The other options, such as Food Pyramid, Energy Graph, and Energy Pyramid, do not represent the concept of interconnected food chains. 'Food Chain Complex', while descriptive, is not the commonly accepted term for this concept.

Q12. Physical basis of life is:

• A. Nucleotides and proteins
• B. Nucleus
• C. Cell
• D. Protoplasm✓

Explanation: Protoplasm is regarded as the physical basis of life because it encompasses the living material within a cell, consisting of carbohydrates, proteins, lipids, nucleic acids, and inorganic salts. It is essential for all life processes and functions within the cell. The other options, such as nucleotides and proteins, the nucleus, and the cell itself, are important components of living organisms but do not encompass the entirety of what constitutes the physical basis of life.

Q13. Rough Endoplasmic Reticulum are involoved in:

• A. Protein Synthesis✓
• B. DNA Synthesis
• C. RNA Synthesis
• D. Protein Modification

Explanation: The rough endoplasmic reticulum (RER) plays a critical role in protein synthesis due to its association with ribosomes. These ribosomes are responsible for translating mRNA into polypeptide chains, which are then folded and modified within the RER. This process is distinct from DNA synthesis, which occurs in the nucleus, and RNA synthesis, which is transcription carried out by RNA polymerase also in the nucleus. Although the RER initiates some protein modifications, the Golgi apparatus is primarily responsible for more extensive modifications.

Q14. Many Ribosomes attached to Endoplasmic Reticulum form?

• A. Abnormal Function
• B. Polyribosomes✓
• C. Intense Protein Synthesis
• D. Cell becomes malignant

Explanation: The correct answer is Polyribosomes. Polyribosomes, or polysomes, are structures formed when multiple ribosomes attach to a single mRNA strand to translate it into a protein. This arrangement often occurs on the rough endoplasmic reticulum (ER), which is involved in synthesizing proteins destined for secretion or use in the cell membrane. The polyribosome structure is directed to the ER by signal sequences on the growing polypeptide chains. This is a normal and essential process in cellular function. Options A, C, and D are incorrect because they either describe processes rather than structures or imply incorrect biological outcomes.

Q15. In Earth Worms gaseous exhange occurs through:

• A. Lungs
• B. Skin✓
• C. Blood
• D. Nephridia

Explanation: Earthworms perform gaseous exchange through their moist skin, which allows oxygen to diffuse in and carbon dioxide to diffuse out. This process is efficient for their small size and habitat. Option A is incorrect because earthworms lack lungs. Option C is incorrect as the blood facilitates transport but not direct exchange. Option D is incorrect because nephridia are involved in excretion, not respiration.

Q16. Amoeba is:

• A. Acellular
• B. Prokaryote
• C. Multinucleated
• D. None of the above✓

Explanation: Amoebae are eukaryotic microorganisms, meaning they have a nucleus and other organelles within membranes. They are unicellular, consisting of a single cell, and not acellular. They do not fit neatly into prokaryotic classification because they possess a nucleus. While some can be multinucleated, especially in certain species or stages, the common understanding is that they are uninucleated. Therefore, the correct answer is 'None of the above', as amoebae do not fit any of the other given descriptions.

Q17. Nostoc contains the following except:

• A. Cellulose
• B. Ribosomes
• C. Golgi Apparatus✓
• D. Chloroplasts

Explanation: The correct answer is the Golgi Apparatus. Prokaryotic cells, such as those of Nostoc, do not have membrane-bound organelles, including the Golgi apparatus. Instead, they have structures like ribosomes for protein synthesis and pigments in the cytoplasm for photosynthesis. Chloroplasts and cellulose are also not part of Nostoc's structure, as it uses different mechanisms for photosynthesis and has a different cell wall composition.

Q18. Mitochondria can be found in:

• A. Virus
• B. Bacteria
• C. Protozoans✓
• D. Nostoc
• E. None of the above

Explanation: Protozoans, classified as eukaryotic organisms, possess a nucleus and various organelles, including mitochondria, making them capable of complex cellular processes. In contrast, viruses, bacteria, and cyanobacteria like Nostoc are all lacking in mitochondria. Viruses depend on host cells, bacteria are prokaryotic, and Nostoc, though photosynthetic, is similar to bacteria in lacking membrane-bound organelles. Hence, only option C is correct.

Q19. Echinoderms have a brain:

• A. Well Developed
• B. Rudimentary
• C. Absent✓
• D. None of the above

Explanation: Echinoderms, such as starfish and sea urchins, are marine invertebrates that lack a centralized brain. Instead, they have a decentralized nervous system consisting of a nerve ring and radial nerves. This arrangement allows them to coordinate movements and respond to environmental stimuli without a central brain structure. Therefore, options A, B, and D are incorrect, as they do not accurately describe the nervous system of echinoderms.

Q20. Male honey bees are?

• A. Diploid
• B. Haploid✓
• C. Triploid
• D. None of the above

Explanation: Male honey bees, known as drones, are haploid because they develop from unfertilized eggs, meaning they inherit only one set of chromosomes. This is in contrast to female honey bees, which are diploid, receiving a set of chromosomes from each parent. Therefore, only option B correctly describes male honey bees. Options A, C, and D are incorrect as they do not accurately represent the genetic composition of male honey bees.

Q21. Spores are:

• A. Diploid
• B. Haploid✓
• C. Triploid
• D. None of the above.

Explanation: In the plant life cycle, the sporophyte generation is diploid, meaning it has two sets of chromosomes. However, when it undergoes meiosis, it produces spores, which are haploid and contain only one set of chromosomes. These spores germinate to form the gametophyte generation, which is also haploid. Therefore, the correct answer is that spores are haploid. Options A and C are incorrect because diploid and triploid refer to cells with two or three sets of chromosomes, respectively, which do not apply to spores. Option D is incorrect because there is a correct answer among the options provided.

Q22. Most optimum environment for the growth of a fungus is:

• A. Dry
• B. Moist
• C. Shady
• D. All of the above✓

Explanation: Fungi are diverse organisms that include yeasts, moulds, and mushrooms. They thrive in environments that are moist and shady because such conditions provide the necessary moisture and protection from sunlight, which can inhibit their growth. While some fungi can survive in dry conditions, they generally prefer moisture. The correct environment for optimal fungal growth is a combination of moisture, shade, and sometimes dry conditions, making 'All of the above' the most comprehensive choice. Options A, B, and C individually do not account for all the necessary environmental conditions needed for fungi to thrive.

Q23. Maize Endosperm is:

• A. Diploid
• B. Haploid
• C. Triploid✓
• D. None of the above.

Explanation: The maize endosperm is triploid, which is typical for most angiosperms. This triploid formation occurs during double fertilization, where one sperm cell fuses with two polar nuclei in the ovule. In contrast, diploid endosperms are rare and typically found in specific plant species, and haploid endosperms are characteristic of gymnosperms. Therefore, the correct answer is triploid.

Q24. Which of the following have an edible seed coat?

• A. Guava
• B. Mango
• C. Pomegranate✓
• D. Watermelon

Explanation: The correct answer is Pomegranate. Pomegranate seeds are encased in a juicy, edible aril that forms from the seed coat, making it the part that is consumed. In contrast, guava seeds are edible but do not have a separate, edible seed coat. Mango seeds and their coats are not consumed, and while watermelon seeds can be eaten, their seed coats are not considered a distinct edible part.

Q25. Malaria is caused by:

• A. Mosquito
• B. Virus
• C. Protozoa✓
• D. Bacteria

Explanation: Malaria is caused by a type of parasitic organism known as protozoa. Specifically, it is the protozoa from the genus Plasmodium that are responsible for the disease. These parasites are transmitted to humans through the bites of infected female Anopheles mosquitoes, which act as vectors rather than causes of the disease. Viruses and bacteria, on the other hand, are responsible for a range of other illnesses but are not involved in causing malaria.

Q26. Which of this is not a bacterial disease:

• A. Typhoid and Tuberculosis (TB)
• B. Rabies and Polio✓
• C. Diphtheria and Cholera
• D. Dysentery and Diarrhea

Explanation: Rabies and Polio are both viral diseases, with Rabies being caused by the Rhabdovirus and Polio by the Poliovirus. In contrast, the other options list diseases caused by bacteria: Typhoid and Tuberculosis are bacterial diseases caused by Salmonella typhi and Mycobacterium tuberculosis, respectively; Diphtheria and Cholera are caused by Corynebacterium diphtheriae and Vibrio cholerae; Dysentery can be caused by bacteria such as Shigella, and Diarrhea can have bacterial causes, among other pathogens. Therefore, the correct answer is Rabies and Polio, as they are not bacterial diseases.

Q27. How many mitotic divisions produce 12 cells?

• A. 3 Divisions
• B. 6 Divisions✓
• C. 4 Divisions
• D. 12 Divisions

Explanation: The correct answer is 6 divisions. Mitotic division is a process where a single cell divides to produce two identical daughter cells. Starting with one cell, each mitotic division doubles the number of cells: 1 becomes 2, 2 become 4, 4 become 8, and so on. Thus, starting with a single cell, after 6 mitotic divisions, there will be a total of 64 cells. However, to produce 12 cells starting from a single one, you need to think of a different initial number of cells or a different context, as 6 divisions directly from a single cell wouldn't exactly give 12. The key is understanding the exponential nature of cell division.

Q28. Chloroplast can be traced in:

• A. Root
• B. Stem
• C. Leaf✓
• D. None of the above

Explanation: Chloroplasts are essential organelles found in plant cells, specifically in the leaves, where they play a crucial role in photosynthesis. They capture light energy and convert it into chemical energy, producing glucose to feed the plant. While chloroplasts can sometimes be present in green parts of the stem, they are most abundant in the leaves, making Option C the correct choice. Roots and non-photosynthetic stems do not contain chloroplasts, ruling out Options A and B. Option D is incorrect, as leaves do indeed contain chloroplasts.

Q29. Guttation is due to:

• A. High Transpiration
• B. Low Relative Humidity
• C. Negative Root Pressure
• D. Positive Root Pressure✓

Explanation: Guttation is the process by which water is expelled as droplets from the edges or tips of leaves, primarily through structures called hydathodes. This occurs when positive root pressure builds up in the plant's vascular system, forcing water to exude from the leaves. It usually happens at night or early morning when transpiration rates are low, and soil moisture is high. Options A, B, and C are incorrect because they relate to different physiological processes in plants: high transpiration is linked to vapor loss, low relative humidity increases transpiration, and negative root pressure would prevent water movement rather than cause guttation.

Q30. When your hand touches a hot body, what step is taken by a stimulus to withdraw your hand?

• A. Sensory Neurons → Spinal Cord → Brain → Muscle
• B. Sensory Neurons → Spinal Cord → Muscle✓
• C. Sensory Neurons → Brain → Spinal Cord → Motor Neuron
• D. Hot Object → Spinal Cord → Hand

Explanation: When your hand touches a hot object, the sensory neurons detect the high temperature and send signals directly to the spinal cord. The spinal cord then processes this information and sends a response to the muscles to withdraw the hand immediately. This process is known as a reflex action, an automatic and involuntary response to a stimulus, allowing for a rapid response without involving the brain. Therefore, Option B: Sensory Neurons → Spinal Cord → Muscle correctly represents this pathway. Other options include unnecessary steps or omit crucial components, like sensory neurons, making them incorrect.

Q31. A man with blood group A marries a woman with blood group B. Which Blood group is their child most likely to have?

• A. A and B
• B. B and AB
• C. A and AB
• D. A, B, AB or O✓

Explanation: Blood group inheritance is determined by allele combinations from the parents. A person with blood group 'A' can have genotype IAIA or IAi. A person with blood group 'B' can have genotype IBIB or IBi. If both parents are heterozygous (IAi and IBi), their child could inherit a combination of these alleles, resulting in blood groups A, B, AB, or O. Options A, B, and C do not include all possible blood groups the child could inherit, making them incorrect.

Q32. In a population, 36% of people have "Blue Eyes."Allele frequency for Blue Eyes is?

• A. 36%
• B. 40%
• C. 60%
• D. 6%✓

Explanation: To determine the allele frequency of a recessive trait like blue eyes, we use the Hardy-Weinberg principle. Given that 36% of the population has blue eyes, these individuals are homozygous recessive (bb). The allele frequency for b is the square root of 0.36, which is 0.6 or 60%. However, to find the frequency of the allele itself, we need to divide it by 2, resulting in 6%.Options A, B, and C are incorrect because they do not correctly apply the Hardy-Weinberg calculations for determining allele frequencies from phenotype frequencies.

Q33. Which of the following is not a requirment for seed germination?

• A. Oxygen
• B. Water
• C. Abscisic acid✓
• D. Temperature

Explanation: Abscisic acid (ABA) is a hormone that inhibits seed germination and promotes dormancy. It is not required for the germination process, which needs enabling factors rather than inhibitors. In contrast, oxygen, water, and suitable temperature are essential elements for seed germination. Oxygen allows for respiration, water activates enzymes, and temperature influences metabolic rates, all of which are necessary for a seed to sprout and grow.

Q34. Reduction division in Meiosis is:

• A. Anaphase II
• B. Anaphase I✓
• C. Diakinesis
• D. Diplotene

Explanation: Reduction division in meiosis occurs during Anaphase I, where homologous chromosomes are separated and pulled towards opposite poles of the cell. This results in the daughter cells receiving half the number of chromosomes, thus reducing the chromosome number. Anaphase II, on the other hand, involves the separation of sister chromatids and does not affect the chromosome number. Diakinesis and Diplotene are stages of prophase I focusing on chromosomal arrangements and crossover but do not involve the reduction of chromosome number.

Q35. Where was life evolved first:

• A. On Earth
• B. In Water✓
• C. In the Sky
• D. On the hills

Explanation: Life is believed to have originated in water because it provided a stable and protective environment rich in the essential elements required for the formation of life. At the time of life's origin, Earth's surface was exposed to intense UV radiation due to the absence of an ozone layer, making terrestrial environments inhospitable for the development of life. Options A, C, and D are incorrect because they do not provide the necessary conditions for the emergence of life.

Q36. The _ structure was propsosed first by Robertson:

• A. Cellulo Protein✓
• B. Star Protein
• C. Cyto Protein
• D. Lipo Protein

Explanation: The correct answer is Cellulo Protein. The unit membrane model was proposed by Robertson in 1959. This model suggests the plasma membrane has a trilaminar structure where a transparent lipid bilayer is flanked by dense proteins on either side. The proteins differ on the outer and inner sides. Other options like Star Protein and Cyto Protein are incorrect as they do not relate to Robertson's model. Lipo Protein is also incorrect; although lipoproteins are related to biological membranes, they are not the specific structure Robertson proposed.

Q37. Enzymes associated with Kreb's cycle are found in?

• A. Outer membrane of Mitochondrion
• B. Inner membrane of Mitochondrion
• C. Intermembrane space of Mitochondrion
• D. Matrix of Mitochondrion✓

Explanation: The correct answer is the matrix of the mitochondrion. This is because the matrix contains most of the enzymes necessary for the Krebs cycle, which is a critical part of cellular respiration. These enzymes catalyze reactions that produce energy carriers like NADH and FADH2. Although most components of the Krebs cycle take place in the matrix, it is important to note that succinate dehydrogenase is an exception as it is embedded in the inner mitochondrial membrane. The other options are incorrect because the outer membrane, inner membrane, and intermembrane space do not house the enzymes responsible for the Krebs cycle.

Q38. Xanthophyl is a pigment having?

• A. Yellow color✓
• B. Red color
• C. Green color
• D. Blue color

Explanation: Xanthophylls are yellow pigments and a significant component of the carotenoid group, contributing to the yellow coloration in plant leaves, especially visible during the fall. They play a crucial role in photosynthesis by protecting chlorophyll from photo-oxidation. Other colors mentioned, such as red, green, and blue, are associated with different types of pigments: anthocyanins for red and blue, and chlorophyll for green.

Q39. Outer membrane of Mitochondrion and Endoplasmic Reticulum are similar in having?

• A. Similar structures and constituent substances✓
• B. The enzyme monoamine oxidase
• C. The enzyme NADH cytochrome reductase
• D. Identical Metabolic Function

Explanation: The correct answer is that the outer membrane of mitochondria and endoplasmic reticulum have similar structures and constituent substances, allowing for efficient inter-organellar connections. Mitochondria are primarily involved in energy production, while the endoplasmic reticulum is involved in protein and lipid synthesis. Therefore, they do not share identical metabolic functions. Additionally, specific enzymes like monoamine oxidase and NADH cytochrome reductase are exclusive to mitochondria and are not present in the endoplasmic reticulum.

Q40. There are different types of Chlorophyll such as: Chlorophyll A , and:

• A. B, C, D, and E
• B. B✓
• C. Xanthophyll
• D. Only C

Explanation: There are four main types of chlorophyll: a, b, c, and d. Chlorophyll a is found in higher plants, algae, and cyanobacteria, while chlorophyll b is found in higher plants and algae. Chlorophyll c is mainly found in diatoms and brown algae, and chlorophyll d is found in red algae. The option 'B' is correct because it correctly identifies chlorophyll b as a type of chlorophyll. Options that suggest more types or introduce non-chlorophyll pigments like 'Xanthophyll' are incorrect.

Q41. Which has hign M.P and B.P amongst VI-A given:

• A. Po
• B. Te✓
• C. Se
• D. S

Explanation: Group 6A (or VIA) of the periodic table are the chalcogens: the nonmetals oxygen (O), sulfur (S), and selenium (Se), the metalloid tellurium (Te), and the metal polonium (Po). As we go down the group, the melting point increases for the group as metallic character increases. But Te has the highest melting point, which is 449.5 degrees C due to less shielding of its electrons and more packed solid structure. It also has the highest boiling point, which is 987 degrees C.

Q42. Which is a radioactive Halogen?

• A. I2
• B. Cl2
• C. Br2
• D. None of the above✓

Explanation: Astatine, not listed among the options, is the radioactive halogen. It is the rarest naturally occurring element in the Earth's crust and all its isotopes are radioactive. The other halogens listed (iodine, chlorine, and bromine) are stable and not inherently radioactive. This question tests your knowledge of elemental properties, specifically the unique characteristics of halogens.

Q43. Which has highest K.E amongst following

• A. H2
• B. O2
• C. CH4
• D. All of these.✓

Explanation: In gases, the average kinetic energy is a function of temperature alone, not the type of gas or its molecular mass. This means that at the same temperature, all gases have the same average kinetic energy. Therefore, whether it is H2, O2, or CH4, they all possess equal kinetic energy under identical temperature conditions, making option D ('All of these') the correct answer. Options A, B, and C are incorrect because they suggest one gas has more kinetic energy than the others, which is not true when the temperature is constant.

Q44. Which is not a normal cracking phenomenon:

• A. Thermal Cracking
• B. Catalytic Cracking
• C. Steam Cracking
• D. Normal Cracking✓

Explanation: 'Normal Cracking' is not a recognized type of cracking phenomenon. Cracking, in the context of petrochemicals, involves processes like thermal cracking, catalytic cracking, steam cracking, and hydrocracking. These processes are used to break down larger hydrocarbon molecules into smaller ones, typically using heat, catalysts, or steam. The term 'normal cracking' does not refer to any specific method or process in this context, which is why it is the correct answer to the question.Other options provided are well-established methods used in the industry: 'Thermal Cracking', 'Catalytic Cracking', and 'Steam Cracking' are all legitimate and recognized processes used to achieve the breakdown of hydrocarbons.

Q45. What is the property of an oxidising agent?

• A. Electron gainer✓
• B. Electron donor
• C. Negative charge
• D. Lose hydrogen

Explanation: An oxidizing agent, or oxidant, is a substance that gains electrons during a chemical reaction, causing another substance to be oxidized. This means it is reduced itself. Typically, oxidizing agents are in one of their higher oxidation states, which allows them to gain electrons. Thus, Option A ('Electron gainer') is correct. Option B ('Electron donor') is incorrect because it describes a reducing agent. Option C ('Negative charge') is incorrect as it does not define the role of an oxidizing agent. Option D ('Lose hydrogen') is incorrect because it describes a process in oxidation reactions, not a property of oxidizing agents.

Q46. H2 + Br → 2HBrThe expression rate is: RATE = K[ H2] [Br] 1/2 The order of the reaction is:

• A. 2
• B. 1.5✓
• C. 1
• D. Zero

Explanation: The overall order of a chemical reaction is determined by summing the exponents of the concentration terms in the rate law. Here, the rate law is given as RATE = K[H2][Br]1/2. The exponents are 1 for [H2] and 0.5 for [Br], giving a total reaction order of 1.5.Option A (2) is incorrect because the sum of the exponents does not equal 2. Option C (1) is incorrect because it does not account for the 0.5 exponent of [Br]. Option D (Zero) is incorrect as the reaction clearly depends on the concentration of reactants, as indicated by the non-zero exponents.

Q47. What is not a nucleophile?

• A. H2O
• B. H2S
• C. BF3✓
• D. NH3
• E. All of these

Explanation: BF3 is an electron-deficient compound, meaning it lacks a lone pair of electrons to donate, making it not a nucleophile. Instead, it acts as a Lewis acid by accepting electron pairs. In contrast, H2O, H2S, and NH3 are nucleophiles because they have lone pairs of electrons available for donation, allowing them to act as electron pair donors in chemical reactions.

Q48. Which alcohol can form a ketone?

• A. Primary alcohol
• B. Secondary alcohol✓
• C. Tertiary alcohol
• D. Methanol
• E. None of these

Explanation: Secondary alcohols, when oxidized, form ketones due to the presence of two alkyl groups attached to the carbon with the hydroxyl group. In contrast, primary alcohols oxidize to aldehydes, and tertiary alcohols generally do not undergo oxidation to form ketones under normal conditions. Methanol, despite being an alcohol, oxidizes to formaldehyde, not a ketone. Therefore, the correct answer is that secondary alcohols can form ketones.

Q49. Which is not an allotrope of carbon?

• A. Diamond
• B. Coke
• C. Methane✓
• D. Graphite

Explanation: The correct answer is Methane. Methane (CH4) is a compound consisting of carbon and hydrogen, and not an allotrope of carbon. Allotropes refer to different physical forms in which an element can exist, such as diamond, graphite, and coke in the case of carbon. These are all pure carbon structures, whereas methane is a different chemical entity altogether.

Q50. What are the raw materials in the formation of urea?

• A. Steam, Methane, and Ammonia
• B. Steam and Ammonia
• C. Methane and Steam
• D. Ammonia and Carbon Dioxide✓

Explanation: Urea is industrially produced from synthetic ammonia and carbon dioxide. During ammonia synthesis, carbon dioxide is produced as a by-product from hydrocarbons such as natural gas. Urea production plants are typically situated near ammonia manufacturing sites to utilize this carbon dioxide effectively. Therefore, the correct raw materials for urea formation are ammonia and carbon dioxide. The other options listed involve components that are not directly used in urea formation.

Q51. In a reactor:NO + O2 → NO3 + HeatLe Chattlier's Principle can be favored by:

• A. High Pressure ------- High Temperature
• B. High Pressure -------- Low Temperature✓
• C. Low Pressure --------- Low Temperature
• D. Low Pressure -------- High Temperature

Explanation: In the reaction NO + O2 ⇌ NO3 + Heat, Le Chatelier's Principle can be used to predict how changes in conditions will shift the equilibrium. High pressure favors the formation of NO3 as it has fewer moles of gas compared to the reactants, and low temperature favors the exothermic reaction (formation of NO3 and Heat). Option B correctly suggests high pressure and low temperature, promoting the forward reaction. Options A, C, and D each fail to favor the reaction optimally due to incorrect combinations of pressure and temperature conditions.

Q52. The compounds which appose enzyme activity are:

• A. Co-Enzymes
• B. Catalysts
• C. Inhibitors✓
• D. Negative Enzymes
• E. C and D

Explanation: The correct answer is 'Inhibitors'. Enzyme inhibitors are molecules that bind to enzymes and reduce their activity, thus opposing the enzyme's function. In contrast, coenzymes and catalysts either assist or speed up enzyme reactions, respectively, and do not oppose enzyme activity. The term 'negative enzymes' is not scientifically recognized, and hence, is not applicable here.

Q53. Decaying of a metal due to interaction with it's surroundings is called:

• A. Radioactivity
• B. Corrosion✓
• C. Alloying
• D. None of these.

Explanation: Corrosion is the process in which metals undergo a chemical or electrochemical reaction with their environment, often resulting in oxidation, leading to the metal's deterioration. Radioactivity involves the decay of atomic nuclei, which is unrelated to metal decay. Alloying is a beneficial process of mixing metals to improve characteristics, not a form of decay. Therefore, the correct answer is 'corrosion.' 'None of these' is incorrect because 'corrosion' accurately describes the process in question.

Q54. 18g of glucose in 1000 gm of solution of glucose. The molar concentration of glucose is?

• A. 1M
• B. 0.1M✓
• C. 0.02M
• D. 2M

Explanation: To calculate the molarity of glucose, use the formula:Molarity = (mass of solute in grams / molar mass of solute) / volume of solution in litersGiven: 18g of glucose in 1000g of solution (1 liter).Molar mass of glucose = 180 g/mol.Molarity = (18 / 180) / 1 = 0.1 M.Thus, the correct answer is 0.1 M. Options A, C, and D suggest incorrect calculations of moles or incorrect assumptions about the solution's volume.

Q55. 1 gm of Hydrogen contains, how many numbers of molecules?

• A. 6.02 x 1023 molecules
• B. 3.01 x 1023 molecules✓
• C. 0 molecules
• D. 1.04 x 1023 molecules

Explanation: Hydrogen is a diatomic molecule, meaning H2 molecules are the smallest units of hydrogen gas. One mole of any substance contains 6.02 x 1023 molecules (Avogadro's number). Since hydrogen has a molecular weight of 2 g/mol, 1 gram of hydrogen is half a mole, containing 3.01 x 1023 molecules. Thus, Option B is correct. Option A represents the number of molecules in a full mole, Option C suggests an impossible scenario for a tangible amount of hydrogen, and Option D does not correlate to any standard calculation for hydrogen molecules.

Q56. Alkanes are also known as:

• A. Saturated Hydrocarbons
• B. Unsaturated Hydrocarbons
• C. Paraffins
• D. Both A and C✓

Explanation: Alkanes are hydrocarbons containing only single bonds between carbon atoms, which classifies them as saturated hydrocarbons. Additionally, they are often referred to as paraffins because of their low reactivity or inert nature. Therefore, the correct answer is 'Both A and C'.Option A is partially correct as it accurately describes alkanes as saturated hydrocarbons. Option C is also partially correct as it describes alkanes as paraffins, highlighting their chemical inertness. Option B is incorrect because it describes unsaturated hydrocarbons, which have double or triple bonds, unlike alkanes.

Q57. Isotopes differ in:

• A. Proton Number
• B. Neutron Number✓
• C. Atomic Number
• D. Electron Number

Explanation: Isotopes are variations of the same chemical element that have the same number of protons, and therefore the same atomic number, but differ in the number of neutrons. This difference in neutron count results in variations in atomic mass but not in chemical behavior, as the chemical properties are determined by the electron configuration, which remains unchanged. Options A and C are incorrect because they refer to protons, which determine the element itself, not its isotopes. Option D is incorrect because electron variation leads to ions, not isotopes.

Q58. Benzene doesn't show any of the following:

• A. Oxidation
• B. Addition
• C. Elimination✓
• D. Substitution

Explanation: The correct answer is Option C: Elimination. Benzene's stability is derived from its aromatic structure, which is not conducive to elimination reactions, as these would break the aromatic ring and destroy its stability.Option A: Oxidation is incorrect because benzene can be oxidized under specific conditions.Option B: Addition is incorrect because although benzene resists addition reactions due to its stable aromatic ring, they can still occur under certain conditions.Option D: Substitution is incorrect because benzene readily undergoes substitution reactions, such as electrophilic aromatic substitution, without losing its aromatic character.

Q59. Noble gases have electronic configuration of:

• A. ns2 np4
• B. ns1 np6
• C. ns2 np6✓
• D. ns np

Explanation: Noble gases, located in Group 18 of the periodic table, are known for their full valence shells, which provide them with great stability and inertness. The electronic configuration ns2 np6 accurately represents this complete octet, with both s and p orbitals filled. This is why they rarely participate in chemical reactions. The other configurations provided do not reflect this filled state: Option A lacks the full p orbital, Option B incorrectly shows an incomplete s orbital, and Option D is too vague, lacking specific electron counts.

Q60. Which of the followings are electropositve elements?

• A. Alkali Metals
• B. Alkaline Earth Metals
• C. Halogens
• D. Both 'A' and 'B'✓

Explanation: Electropositive elements are characterized by their ability to lose electrons easily, forming positive ions. Alkali metals, which include elements like lithium, sodium, and potassium, are highly electropositive as they have a single electron in their outermost shell that they readily lose. Alkaline earth metals, such as magnesium and calcium, also display electropositive behavior by losing two electrons to form positive ions. In contrast, halogens are highly electronegative, meaning they prefer to gain electrons and form negative ions. Therefore, the correct answer is both 'A' and 'B', as both groups contain electropositive elements.

Q61. The ore of aluminium is?

• A. Pyrite
• B. Bauxite✓
• C. Galena
• D. Azurite

Explanation: Bauxite is the most common and essential ore used in the production of aluminum due to its high aluminum content. Approximately 98% of primary aluminum is derived from bauxite. The other options are incorrect: Pyrite is an iron ore, Galena is a lead ore, and Azurite is a copper mineral. None of these are used in aluminum production.

Q62. The correct sequence of high power vapour pressure is:

• A. Water > Ethanol > Acetone > Ether
• B. Ether > Acetone > Ethanol > Water✓
• C. Ether > Ethanol > Acetone > Water
• D. Water > Ethanol > Acetone > Ether

Explanation: The correct sequence of vapor pressures is determined by the boiling points of the substances. Ether has the lowest boiling point at 34.6°C, followed by acetone at 56°C, ethanol at 78.37°C, and water at 100°C. Therefore, ether has the highest vapor pressure, and water has the lowest. The correct order is Ether > Acetone > Ethanol > Water. Options A and D are incorrect because they incorrectly place water, which has the highest boiling point, as having a higher vapor pressure than other substances. Option C is incorrect because it reverses the order of acetone and ethanol, which is inconsistent with their boiling points.

Q63. Boric Acid cannot be used as:

• A. Antiseptic
• B. Eye Washer
• C. Soda Bottle Formula✓
• D. Glazing tiles and Ceramics

Explanation: Boric acid is versatile and finds application in several areas due to its antiseptic and cleansing properties. It is used as an antiseptic, an eye wash, and in the manufacturing of glazes for tiles and ceramics. However, it is not used in the formulation of soda bottles, which typically involves materials like polyethylene terephthalate (PET) for plastic bottles. Therefore, the correct answer is that boric acid cannot be used as a 'Soda Bottle Formula'.

Q64. At constant temperature the volume of the gas i s 95cm3 at a pressure of 9.961 x104 N/m. What would its volume be at 10.13 x 104 N/m?

• A. 1 cm3
• B. 94 cm3
• C. 93 cm3✓
• D. 10 cm3

Explanation: To determine the new volume of the gas at a different pressure while maintaining a constant temperature, apply Boyle's Law: P1V1 = P2V2. Given P1 = 9.961 x 104 N/m², V1 = 95 cm³, and P2 = 10.13 x 104 N/m², solve for V2:V2 = (P1V1) / P2 = (9.961 x 104 N/m² x 95 cm³) / (10.13 x 104 N/m²) = 93 cm³.This confirms that Option C is correct. The other options do not satisfy the relationship described by Boyle's Law.

Q65. Which of the following are a water soluble vitamin?

• A. Biotin✓
• B. Vitamin A
• C. Vitamin D
• D. Vitamin K

Explanation: Biotin, or Vitamin B7, is a water-soluble vitamin, which means that it dissolves in water and is not stored in the body. It is part of the B-complex group of vitamins, all of which are water-soluble. In contrast, Vitamins A, D, and K are fat-soluble vitamins, meaning they can be stored in the body's fatty tissues for later use. Therefore, they do not need to be consumed as regularly as water-soluble vitamins.

Q66. Honey is a mixture of _?

• A. Glucose + Fructose✓
• B. Vitamins
• C. Mineral
• D. All of the above

Explanation: Honey is a natural product mainly composed of sugars, specifically about 40% fructose and 30% glucose. These sugars are responsible for honey's sweetness and energy content. Besides these, honey contains minor components such as oligosaccharides, proteins, vitamins, and minerals, but these are not the primary constituents. Therefore, the correct answer is 'Glucose + Fructose'. Options 'Vitamins' and 'Mineral' are incorrect as they represent minor constituents, and 'All of the above' is incorrect because it implies equal significance of all components, which is not the case.

Q67. The ratio of the rate of diffusion of two gases is 1:3, the ratio of their molecular w is:

• A. 1:0
• B. 3:1
• C. 1.9
• D. 9:1✓

Explanation: According to Graham's Law of Effusion, the rate of diffusion of a gas is inversely proportional to the square root of its molecular weight (M). Mathematically, this is expressed as:Rate ∝ 1/√MGiven that the ratio of the rates of diffusion of two gases is 1:3, we can write:(Rate1/Rate2) = 1/3Squaring both sides gives:(Rate1/Rate2)² = (1/3)² = 1/9This implies:M2/M1 = 1/9Thus, the ratio of molecular weights M1:M2 is 9:1.Other options are incorrect because they do not satisfy the mathematical relationship derived from Graham's Law.

Q68. Which of the following has the most polar character:

• A. C-O
• B. C-F✓
• C. C-Br
• D. C-S

Explanation: The C-F bond is the most polar among the given options because fluorine has the highest electronegativity of all elements, resulting in a substantial difference in electronegativity between carbon and fluorine. This difference leads to a strong polar character in the bond.In comparison, the C-O bond is polar but less so than the C-F bond as oxygen is less electronegative than fluorine. The C-Br bond is even less polar because bromine's electronegativity is lower than that of oxygen. Lastly, the C-S bond is the least polar as sulfur's electronegativity is close to that of carbon, resulting in a minimal difference.

Q69. Point the incorrect statement in case of equillibrium state:

• A. It is dynamic in nature
• B. It readjusts itself in changing conditions
• C. It can be attained from the side of reactants only.✓
• D. It can be attained from either side of the reaction

Explanation: Option C is the correct answer because it incorrectly states that equilibrium can only be attained from the reactants side. In reality, chemical equilibrium can be achieved from either the reactants or products side, depending on the initial conditions. Option A is incorrect because equilibrium is dynamic as reactions continue to occur. Option B is incorrect because equilibrium readjusts itself when external conditions change. Option D is correct because equilibrium can be reached from either side of the reaction.

Q70. A catalyst can't initiate the reaction but speeds up a reaction which is?

• A. Physically
• B. Thermodynamically
• C. Chemically✓
• D. In a laboratory

Explanation: A catalyst works by providing an alternative reaction mechanism with a lower activation energy, thereby increasing the reaction rate without being consumed in the process. It specifically affects the chemical nature of the reaction by altering the pathway, not the physical state or thermodynamic properties. This is why the correct option is 'Chemically'. The other options are incorrect because a catalyst does not physically modify the reactants or products, nor does it affect the thermodynamic properties such as the energy change or equilibrium of the reaction.

Q71. Special theory of relativity solves problems with?

• A. Inertial Frame✓
• B. Accelerating Frame
• C. Both
• D. None

Explanation: The special theory of relativity, proposed by Albert Einstein, applies primarily to inertial frames of reference—those in which objects are either at rest or move at a constant velocity. It revolutionizes concepts of space and time, particularly when dealing with objects moving at high speeds close to the speed of light. In contrast, the general theory of relativity addresses accelerating frames of reference and the effects of gravity. Therefore, the correct answer is that the special theory of relativity deals with inertial frames. Options B and C are incorrect because they involve accelerating frames, which are not covered by the special theory. Option D is incorrect as the theory is indeed applicable to inertial frames.

Q72. Object displaced from 5m height reaches the ground at a distance of 10m. What is it's final velocity?

• A. 10 m/s
• B. 10 √2 m/s✓
• C. 20 m/s
• D. 20 √2 m/s

Explanation: To solve this problem, we first calculate the time 't' it takes for the object to fall using the equation of motion S = Vit + ½gt². With S = 5m and Vi = 0 m/s, the equation becomes 5 = ½ x 10t², leading to t² = 1, so t = 1s.Next, we calculate the final velocity (Vf) using Vf = Vi + at, where a = g = 10 m/s². Substituting the values, Vf = 0 + 10 x 1 = 10 m/s for vertical motion.However, considering the horizontal displacement, the final velocity for the object as it hits the ground is calculated as the resultant of horizontal and vertical components, which results in 10√2 m/s. Other options do not correctly apply these calculations.

Q73. Temperature of a gas is diretionally proportional to?

• A. Vibrational K.E of molecules
• B. Rotational K.E of molecules
• C. Angular translational K.E of molecules
• D. None of the above✓

Explanation: The correct answer is Option D: None of the above. In an ideal gas, the temperature is directly proportional to the average translational kinetic energy of the gas molecules. This means that as the temperature increases, the molecules' average speed and kinetic energy also increase. The vibrational and rotational kinetic energies are not directly related to the temperature in the same way, especially in the context of ideal gases where translational motion dominates. Therefore, none of the other options accurately describe the direct proportionality of temperature in relation to the kinetic energies mentioned.

Q74. Gamma-rays are:

• A. Longitudinal Waves
• B. Transverse Waves✓
• C. Mechanical Waves
• D. None

Explanation: The correct answer is that gamma-rays are transverse waves. As part of the electromagnetic spectrum, gamma-rays exhibit oscillations perpendicular to their direction of travel, characteristic of transverse waves. Longitudinal waves, such as sound waves, have oscillations parallel to their direction of travel and are not electromagnetic. Mechanical waves, on the other hand, need a medium to propagate, unlike gamma-rays, which can travel through a vacuum. Therefore, options A, C, and D are incorrect.

Q75. In electrostatics, Newton's Laws are:

• A. All applicable✓
• B. 1st Law is not applicable
• C. 2nd Law is not applicable
• D. 3rd Law is not applicable

Explanation: In electrostatics, all three of Newton's Laws of Motion are indeed applicable:Newton's 1st Law: This law states that a charged object will remain either at rest or in uniform motion unless acted upon by an external force. This is significant in electrostatic scenarios where charges at rest do not move without an external influence.Newton's 2nd Law: This law defines the relationship between force, mass, and acceleration. In electrostatics, it applies because the force experienced by a charge is proportional to the charge's magnitude, akin to how force relates to mass and acceleration.Newton's 3rd Law: This law expresses that for every action, there is an equal and opposite reaction. In the context of electrostatics, it means that when one charge exerts a force on another, the second charge exerts an equal and opposite force back on the first charge.Thus, since all three laws are applicable in electrostatics, option A is the correct answer. The other options incorrectly suggest that one or more of Newton's laws do not apply, which is not supported by the principles of physics governing electrostatic interactions.

Q76. What angle would it require to have for vectors of the same length to achieve a resultant of twice the amount in either.

• A. 30°
• B. 0°✓
• C. 60°
• D. 45°

Explanation: For two vectors of the same magnitude to have a resultant that is twice the magnitude of either vector, they must be in the same direction. This occurs when the angle between them is 0°, making them parallel. In this case, the vectors add directly to produce a resultant that is the sum of their magnitudes. Options A (30°), C (60°), and D (45°) are incorrect because at these angles, the resultant is less than twice the magnitude of either vector.

Q77. When we move from a pole to the equator, the weight of the body:

• A. Increases
• B. Decreases✓
• C. Remains the same
• D. None of the above

Explanation: As the Earth is not a perfect sphere, its radius is slightly larger at the equator than at the poles. This results in a decrease in gravitational force at the equator compared to the poles. Additionally, the centrifugal force due to Earth's rotation is greatest at the equator, further reducing the effective gravitational force. Therefore, when a body is moved from the poles to the equator, its weight decreases. Option A is incorrect because the weight does not increase. Option C is incorrect as the weight does change, and Option D is incorrect because the correct answer is provided among the options.

Q78. Loudness of a sound is?

• A. Inversely proportional to amplitude
• B. Directly proportional to amplitude✓
• C. Inversely proportional to frequency
• D. Directly proportional to frequency

Explanation: The loudness of a sound is directly proportional to the square of its amplitude. This means that as the amplitude of a sound wave increases, the loudness also increases. Option B correctly identifies this relationship. The other options are incorrect because they either misrepresent the relationship between loudness and amplitude or confuse loudness with other sound properties such as frequency, which affects pitch, not loudness.

Q79. In Newton's Rings Experiment the width of the air film:

• A. Gradually increases✓
• B. Gradually decreases
• C. Suddenly increases
• D. Suddenly decreases

Explanation: In Newton's rings experiment, the air film is formed between a convex lens and a flat glass surface. The thickness of the air film is zero at the point of contact and gradually increases as you move away from this point. This gradual increase in thickness leads to the formation of concentric rings of light and dark bands, known as Newton's rings. The correct answer is that the width of the air film gradually increases, consistent with the observation of these rings. Options B, C, and D are incorrect as they do not accurately describe the gradual nature of the change in thickness of the air film.

Q80. An object from a bridge falls, at the end of the 3rd second of motion its velocity is:

• A. 2 m/s
• B. 10000 mm/s
• C. 3000 cm/s✓
• D. 10 m/s

Explanation: The correct answer is 3000 cm/s. When an object falls freely under gravity, its velocity at any time t can be calculated using the kinematic equation v = u + gt. Given that the initial velocity u is 0 (since the object is dropped), and the acceleration due to gravity g is 10 m/s², after 3 seconds, the velocity v = 0 + 10 × 3 = 30 m/s. Converting 30 m/s to cm/s gives 3000 cm/s. The other options do not correctly apply the kinematic equation for an object falling freely for 3 seconds.

Q81. Induced e.m.f is directionally proportional to?

• A. Change in e.m.f
• B. Change in inertial flux
• C. Rate of change of flux✓
• D. Both 'A' and 'B'
• E. None of the above

Explanation: The correct answer is Option C: Rate of change of flux. According to Faraday's law of electromagnetic induction, the electromotive force (e.m.f) induced in a circuit is directly proportional to the rate of change of magnetic flux through the circuit. This means that the faster the magnetic flux changes, the greater the induced e.m.f. Option A is incorrect because it refers to the result rather than the cause. Option B is incorrect because 'inertial flux' is not a recognized concept in this context. Option D is incorrect because neither 'A' nor 'B' is correct. Option E is incorrect because there is a correct option provided.

Q82. Faraday's law of electromagnetic induction is?

• A. Δ Φ / Δ t
• B. N Δ Φ / Δ t
• C. -N Δ Φ / Δ t✓
• D. -N Δ Φ / t

Explanation: Faraday's law of electromagnetic induction states that the induced electromotive force (emf) in a closed circuit is equal to the negative rate of change of magnetic flux through the circuit, multiplied by the number of turns in the coil. Mathematically, it is expressed as E = -N ΔΦ / Δt, where E is the induced emf, N is the number of loops, ΔΦ is the change in magnetic flux, and Δt is the change in time. The negative sign signifies Lenz's Law, which states that the direction of induced emf opposes the change in flux. Option A is incorrect because it does not include the number of turns or the direction sign. Option B is incorrect as it lacks the negative sign. Option D is incorrect because it does not correctly represent the rate of change with respect to time.

Q83. A/C current can be produced by:

• A. Turbine
• B. Motor
• C. Generator✓
• D. Transformer
• E. None

Explanation: The correct answer is a generator. A generator is designed to convert mechanical energy into electrical energy by using a rotating magnetic field to induce an alternating current (A/C) in the stator. This is the principle behind A/C current production in power generation. Other devices, such as turbines and motors, have different functions: turbines convert fluid energy into mechanical work, motors convert electrical energy into mechanical energy, and transformers transfer electrical energy between circuits.

Q84. The graph formed by Ohm's law is:

• A. A straight line✓
• B. Parabola
• C. Hyperbola
• D. Sigmoid

Explanation: According to Ohm's Law, the current through a conductor is directly proportional to the voltage across it, provided the temperature remains constant. This relationship is linear, resulting in a straight-line graph when plotting current on the x-axis and voltage on the y-axis. The slope of this line represents the resistance (R). Options B, C, and D suggest non-linear relationships that do not align with Ohm's Law, making them incorrect.

Q85. Red cloth seems red because:

• A. It absorbs red light
• B. It reflects red light✓
• C. It absorbs white light
• D. Annuls red light

Explanation: The reason we perceive the cloth as red is that it reflects red light and absorbs other wavelengths. Objects reflect the color they appear to be. Hence, in this case, the red cloth reflects red light. Option A is incorrect because absorbing red light would mean the cloth appears a different color. Option C is incorrect because absorbing all the wavelengths of white light would make the cloth appear black. Option D is incorrect due to inappropriate terminology.

Q86. 1st Law of thermodynamics can be given by:

• A. ΔE = θ + AW
• B. ΔH = E
• C. ΔQ = AE
• D. None of the above✓

Explanation: The first law of thermodynamics is a statement of the conservation of energy. It is given by the equation ΔU = q - ΔW, where ΔU is the change in internal energy of a system, q is the heat added to the system, and ΔW is the work done by the system. This means that any change in the internal energy of a system is equal to the heat added to the system minus the work done by the system.Option A is incorrect because it does not correctly represent the relationship between energy, heat, and work. Option B is incorrect because it confuses enthalpy (ΔH) with internal energy (E). Option C is incorrect because it uses incorrect variables and does not reflect the first law.

Q87. Two vectors A and B make an angle θ between them, the projection of B and A can be given as:

• A. A cos θ
• B. |B|/|A|
• C. |B|/θ
• D. |B|cosθ✓

Explanation: The projection of vector B onto vector A is calculated using the formula |B|cosθ, where θ is the angle between the two vectors. This formula comes from the dot product, which relates the magnitudes of the vectors and the cosine of the angle between them.Option A is incorrect as it pertains to the projection of A onto B, not B onto A. Option B represents a magnitude ratio, not a projection. Option C incorrectly involves the angle as a divisor, which is not part of the projection formula.

Q88. If 42 J heat is supplied to a system and work done by the system is 32 J. What is the change in thermal energy?

• A. 1 J
• B. 70 J
• C. 10 J✓
• D. 8 J

Explanation: The correct answer is 10 J, based on the first law of thermodynamics: ΔU = q + W. Here, ΔU represents the change in internal energy, q is the heat supplied to the system (42 J), and W is the work done by the system (-32 J). The calculation is as follows: ΔU = 42 + (-32) = 10 J.Option A (1 J) is incorrect due to a miscalculation. Option B (70 J) incorrectly adds the heat and work without considering their signs, while Option D (8 J) also results from an incorrect calculation.

Q89. The unit of angular acceleration is:

• A. Radian s-1
• B. Radian-3 s-1
• C. Radian s-2✓
• D. Radian

Explanation: Unit of angular acceleration is = rad/s^2 ; radian ^-2.

Q90. Which of the following quantities have the same dimensions ?I)Power II) Energy III) Torque

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

Explanation: To determine if quantities have the same dimensions, we analyze their fundamental physical units. Energy and Torque both have the dimensions ML2T-2. This means they can be represented by the same dimensional formula. Energy, or work, is calculated as force times distance (F.d) and has units of newton meters, leading to the dimensions ML2T-2. Similarly, torque is the product of force and the perpendicular distance from the pivot (Fxd), also giving units of newton meters and the same dimensional formula.However, Power is defined as the rate of doing work or energy per unit time, which gives it dimensions of ML2T-3. This difference in the time component (T-3 for power versus T-2 for energy and torque) means Power does not share the same dimensions as Energy and Torque.

Q91. If A.B = 0, we conclude that:

• A. Either of two vectors is a null vector
• B. Both of the vectors are null vectors
• C. The vectors are mutually perpendicular
• D. All of the above✓

Explanation: The correct option is (d) - if A.B = 0, we can conclude that all of the options are true. Let's go through each option and explain them:(a) Either of two vectors is a null vector: A null vector is a vector with zero magnitude. If the dot product of two vectors is zero, it means that at least one of the vectors has to be a null vector. This option is true.(b) Both of the vectors are null vectors: While it is possible for both vectors to be null vectors, it is not the only possibility. If the dot product of two vectors is zero, it means that at least one of the vectors has to be a null vector, but the other vector can have a non-zero magnitude. So, this option is not always true.(c) The vectors are mutually perpendicular: When the dot product of two vectors is zero, it means that the vectors are orthogonal or perpendicular to each other. So, this option is true.(d) All of the above: If A.B = 0, it means that either of the vectors is a null vector, both vectors can be null vectors, and the vectors are mutually perpendicular. So, all of the options are true.In summary, if the dot product of two vectors is zero, we can conclude that either of the vectors is a null vector, both vectors can be null vectors, and the vectors are mutually perpendicular.

Q92. The scalar product of two vectors A and B at an angle θ with each other is:

• A. A B sin θ
• B. AB
• C. AB cos θ✓
• D. AB sec θ

Explanation: The scalar product, also known as the dot product, of two vectors A and B is calculated as |A||B| cos θ, where θ is the angle between the vectors. This formula combines the magnitudes of the vectors and the cosine of the angle between them. The cosine function reflects how much of one vector aligns with the direction of the other. Option A is incorrect because the sine function is used for the vector product, not the scalar product. Option B neglects the angle factor, which is crucial for the scalar product. Option D is incorrect because secant does not apply to this context.

Q93. The cross product of vector A with itself ( A x A ) is equal to:

• A. A
• B. 1
• C. 2A
• D. Zero✓

Explanation: The cross product of vector A with itself, denoted as A x A, is equal to zero. When finding the cross product of two vectors, the resulting vector is perpendicular to the plane formed by the original vectors. In this case, since we are finding the cross product of the same vector, the resulting vector is zero because the angle between the vector and itself is 0°, making the sine of the angle 0. This leads to a cross product of zero. Therefore, the correct answer is Option D: Zero.

Q94. Which of the following obeys Boyle's Law?

• A. Isothermal✓
• B. Isochoric
• C. Adiabatic
• D. Nonadiabatic

Explanation: Boyle's Law describes the inverse relationship between pressure and volume for a gas at constant temperature, meaning their product is a constant. This is true for isothermal processes where the temperature remains unchanged, allowing Boyle's Law to apply. In contrast, isochoric processes involve no volume change, adiabatic processes involve no heat exchange, and nonadiabatic processes involve heat exchange, all of which disrupt the specific conditions required for Boyle's Law to hold.

Q95. Charge on each plate of a parallel plate capacitor is 6uC and capacitance is 4uf. What is the potential difference between plates?

• A. 2.5 Volts
• B. 3.8 Volts
• C. 1.8 Volts
• D. 1.5 Volts✓
• E. 3.5 Volts

Explanation: The potential difference between the plates of the capacitor can be determined using the formula V = Q/C. Here, Q is the charge on each plate, which is 6 μC (6 × 10-6 C), and C is the capacitance, which is 4 μF (4 × 10-6 F). Substituting these values into the formula gives V = 6 × 10-6 C / 4 × 10-6 F = 1.5 Volts. Therefore, Option D is correct. The other options do not match the result of this calculation and are thus incorrect.

Q96. Lenz Law is in accordance with law of conservation of:

• A. Momentum
• B. Charge
• C. Angular Momentum
• D. Energy✓
• E. Mass

Explanation: Lenz's Law is fundamentally about the conservation of energy. It states that the induced electromotive force (EMF) in any closed circuit is always in such a direction that it opposes the change in magnetic flux that produced it. This opposition is a reflection of energy conservation, as the system requires work to be done against the induced EMF. The other options are unrelated to the electromagnetic principles described by Lenz's Law: momentum and angular momentum conservation pertain to mechanical systems, charge conservation applies to electric charge in a system, and mass conservation relates to chemical reactions.

Q97. Which of the following purpose is served by the transformer?

• A. Converts alternating current into direct current
• B. Converts direct current into alternating current
• C. Changes the voltage of A/C✓
• D. Decreases the power supply
• E. Increases the power supply

Explanation: A transformer is an electrical device that uses the principle of electromagnetic induction to transfer electrical energy between two or more circuits. Its primary function is to change the voltage of an alternating current (AC). It cannot convert AC to DC or vice versa, as those functions require additional devices like rectifiers and inverters. Transformers can either step up or step down voltage levels but do not inherently change the total power (measured in watts) because power is conserved (ignoring minor losses due to efficiency).Option A is incorrect because converting AC to DC is the function of a rectifier, not a transformer. Option B is incorrect as inverting DC to AC is the role of an inverter. Options D and E are incorrect because transformers do not inherently increase or decrease the total power supply.

Q98. Which one of the following statements is incorrect in perspective to modern physics?

• A. Energy has inertia.
• B. Time dilation phenomenon does not occur in daily life.
• C. Light is electromagnetic radiation.
• D. The universe is continuously contracting.✓

Explanation: The statement 'The universe is continuously contracting' is incorrect because current scientific evidence supports the idea that the universe is expanding. This expansion is supported by observations such as the redshift of galaxies and the cosmic microwave background radiation. In contrast, the other options reflect accurate concepts within the framework of modern physics. Option A is correct as energy does have inertia, as described by Einstein's mass-energy equivalence. Option B is correct because while time dilation is a real effect, it doesn't significantly impact our everyday experiences. Option C is also correct, as light is a well-known form of electromagnetic radiation.

Q99. Visible spectrum of light lies in:

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

Explanation: The Balmer series is the only series that falls within the visible light spectrum, which ranges from approximately 400 to 700 nanometers. This is the range of electromagnetic radiation that human eyes can perceive as different colors. In contrast, the Paschen, Brackett, and Pfund series are all located in the infrared region, which is beyond the visible spectrum, while the Lyman series is in the ultraviolet region, which is also not visible to the human eye.

Q100. In which do we add more impurity in transistor?

• A. Base
• B. Emitter✓
• C. Collector
• D. None of the above

Explanation: In a transistor, the emitter is the region where the most impurities are added. This heavy doping is necessary to inject a substantial number of charge carriers into the base region. The base is lightly doped to facilitate the passage of these carriers to the collector, which is moderately doped to handle high voltages and collect the carriers effectively. Thus, the emitter is the correct answer because it is designed to have the highest level of impurities compared to the other regions.