Sindh Mcat Nts 2011 Duhs And Jsmu — Solved Past Paper with Answers

Q1. Identify the word or phrase that needs to be changed for the sentence to be correct:How will they got across the river if the ferry is not running?

• A. Will
• B. Got across✓
• C. If
• D. Running
• E. No error

Explanation: The sentence aims to inquire about future possibilities. The phrase “got across” is in the past tense and does not fit with the modal verb “will,” which denotes future actions. The correct phrase should be “get across” to match the future tense structure initiated by “will.” The other components, such as “will,” “if,” and “running,” are correct and appropriately used within the sentence’s context.

Q2. Identify the word or phrase that needs to be changed for the sentence to be correct:Children depend on their parents for food and clothing.

• A. Depend
• B. Their
• C. For
• D. And
• E. No error✓

Explanation: The sentence 'Children depend on their parents for food and clothing' is correctly constructed with no grammatical errors. Each component, including the verb phrase 'depend on,' the possessive pronoun 'their,' the preposition 'for,' and the conjunction 'and,' is used appropriately. Therefore, Option E: No error is the correct choice. Options A-D are incorrect because each word they highlight is used correctly in the sentence.

Q3. Choose the correct antonym to the word in capital letters.ASSERTION

• A. Statement
• B. Denial✓
• C. Claim
• D. Unrest
• E. tiring

Explanation: The word Assertion means making a confident and forceful statement of fact or belief. The word that is most nearly opposite in meaning is denial, which involves refusing to accept something as true.

Q4. Choose the lettered word or phrase that is most nearly opposite in meaning to the word in capital letters.OBSTINATE

• A. Persistent
• B. Constant
• C. Courageous
• D. Flexible✓

Explanation: The word obstinate refers to someone who stubbornly refuses to change their opinion or chosen course of action despite attempts to persuade them otherwise. The opposite of this is FLEXIBLE, which describes someone who is adaptable and open to change.

Q5. Choose the word most similar in meaning to the capitalized ones. UNAMBIGUOUS

• A. Stagnant
• B. Hidden
• C. Clear✓
• D. Muddy
• E. Grubby

Explanation: The word 'unambiguous' means 'without any doubt' or 'clearly expressed.' The term 'clear' is synonymous with unambiguous as it indicates something easy to understand or interpret.

Q6. Choose the word most similar in meaning to the capitalized one.WRECKED

• A. Defined
• B. Developed
• C. Registered
• D. Ruined✓

Explanation: The word 'wrecked' means to be completely destroyed or ruined. The closest synonym among the options is 'ruined,' as both words convey the idea of severe damage or disintegration.

Q7. Read the following passage to answer the given question;The fact that we were all as safe as kittens under a cook-stove did not, however, assuage in the least the fine despair and the grotesque desperation which seized upon the residents of the East Side when the cry spread like a grass fire that the dam had given way. Some of the most dignified, staid, cynical, and clear thinking men in town abandoned their wives, stenographers, homes, and offices and ran east. There are few alarms in the world more terrifying than 'The dam has broken!' There are few persons capable of stopping to reason when that clarion cry strikes upon their ears, even persons who live in towns no nearer than five hundred miles to a dam.The phrase "spread like a grass fire" means

• A. Rapid spread✓
• B. Firefighting
• C. Grass growth
• D. Dreadful sight
• E. Hidden news

Explanation: The phrase 'spread like a grass fire' is a metaphor used to describe something that spreads very quickly and widely, akin to how a fire can rapidly move through dry grass. In the passage, it illustrates the swift dissemination of panic among the residents.

Q8. Read the following passage to answer the given question;The fact that we were all as safe as kittens under a cook-stove did not, however, assuage in the least the fine despair and the grotesque desperation which seized upon the residents of the East Side when the cry spread like a grass fire that the dam had given way. Some of the most dignified, staid, cynical, and clear-thinking men in town abandoned their wives, stenographers, homes, and offices and ran east. There are few alarms in the world more terrifying than 'The dam has broken!' There are few persons capable of stopping to reason when that clarion cry strikes upon their ears, even persons who live in towns no nearer than five hundred miles to a dam.Identify the phrase in which the people of the East Side experienced one of the deadliest fears of their lives:

• A. "The dam has been destroyed!"
• B. "The dam is safe!"
• C. "The dam has broken!"✓
• D. "The dam has not broken!"
• E. "The dam is overflowing!"

Explanation: The phrase 'The dam has broken!' is explicitly mentioned in the passage as causing widespread fear and panic among the residents of the East Side. This fear is described as a 'clarion cry' that is particularly terrifying, leading even rational and clear-thinking individuals to act irrationally. Other options either do not appear in the passage or convey a meaning that would not instill fear.

Q9. Complete the sentence by choosing the most appropriate word, from the given lettered choices (A to E) below each. The injured player was taken _ the field.

• A. Of
• B. Off✓
• C. Out
• D. In
• E. By

Explanation: The correct answer is “off” because it effectively conveys the action of removing the injured player from the field. The preposition 'off' indicates a separation or removal from the field, which is appropriate in this context. The other options are incorrect because they do not convey the necessary movement or change in position. 'Of' indicates possession, 'out' suggests leaving an enclosed space, 'in' suggests entering, and 'by' suggests proximity, none of which fit the context of the sentence.

Q10. Complete the sentence by choosing the most appropriate word, from the given lettered choices (A to E) below each. The box is _ green outside and white inside.

• A. Carved
• B. Created
• C. Painted✓
• D. Chiseled
• E. Molded

Explanation: The correct answer is “painted” because it accurately describes the box as having an exterior that is covered with paint, matching the colors specified: green outside and white inside. The other options describe processes or characteristics unrelated to painting or describing color, such as carving, creating, chiseling, or molding.

Q11. Which of the following fungi is utilized in the baking industry?

• A. Mushrooms
• B. Yeast✓
• C. Bread mold
• D. Penicillium
• E. Penicillium Neomycin

Explanation: Yeast is the correct answer because it is used extensively in the baking industry for bread-making. It ferments sugars in the dough, producing carbon dioxide gas that causes the dough to rise. This process imparts a light and airy texture to the bread. Other options, such as mushrooms, bread mold, and Penicillium, are not involved in baking: mushrooms are culinary ingredients, bread mold is a spoilage organism, and Penicillium is known for antibiotic production and cheese fermentation, not baking.

Q12. Which of the following is included in Bryophytes?

• A. Mosses✓
• B. Club mosses
• C. Ferns
• D. Seed plants
• E. Horse tails

Explanation: Bryophytes are non-vascular plants classified under the division Bryophyta. They consist of three main groups: mosses, liverworts, and hornworts. Mosses are indeed bryophytes, characterized by their simple structure lacking true roots, stems, and leaves. Instead, they have rhizoids for anchorage and nutrient absorption.

Q13. Species of Phylum Platyhelminthes are:

• A. Roundworms
• B. Flatworms✓
• C. Hookworms
• D. Threadworms
• E. Pinworms

Explanation: The phylum Platyhelminthes consists of flatworms, which are named for their flat, dorsoventrally flattened bodies. This sets them apart from other worm-like organisms, such as roundworms (Nematoda), which have a cylindrical shape. Flatworms are simple, unsegmented invertebrates with bilateral symmetry. Other options like hookworms, threadworms, and pinworms are all roundworms and do not belong to the Platyhelminthes phylum.

Q14. A characteristic feature of Echinoderm is:

• A. Canal system
• B. Water vascular system✓
• C. Tracheal system
• D. Blood vascular system
• E. None of these

Explanation: The defining feature of echinoderms is their water vascular system, which aids in locomotion, feeding, and respiration. This system is unique to echinoderms and distinguishes them from other phyla. The canal system is found in sponges, the tracheal system is absent in echinoderms and unique to terrestrial arthropods, and while echinoderms do have a blood vascular system, it is not as distinctive as the water vascular system.

Q15. The light dependent reaction of photosynthesis occurs in:

• A. Stroma of chloroplast
• B. Guard cells of stomata
• C. Thylakoid membrane of chloroplast✓
• D. Cytoplasm of leaf cell

Explanation: The correct answer is the thylakoid membrane of the chloroplast. The light-dependent reactions of photosynthesis occur in these membranes, where chlorophyll absorbs light energy. This energy is then converted into chemical energy in the form of ATP and NADPH, which are essential for the subsequent light-independent reactions (Calvin cycle) in the stroma.

Q16. The end product of Glycolysis is:

• A. Glucose-6-phosphate
• B. Fructose-6-phosphate
• C. Pyruvate✓
• D. 3-Phosphoglycerate
• E. Phosphoglyceraldehyde

Explanation: The end product of glycolysis is pyruvate. During glycolysis, one molecule of glucose is broken down into two molecules of pyruvate, yielding a net gain of two molecules of ATP and two molecules of NADH. Pyruvate can then enter the mitochondria to be further processed in the citric acid cycle if oxygen is present, or it can undergo fermentation under anaerobic conditions. The incorrect options listed are intermediates in the glycolytic pathway, not final products.

Q17. The massive accumulation of blood within a tissue is called:

• A. Hemorrhage
• B. Haematoma✓
• C. Hepatoma
• D. Haemocoel
• E. Haematemesis

Explanation: A hematoma is a localized collection of blood outside vessels, usually due to vessel injury.

Q18. Malpighian tubules are involved in excretion in:

• A. Cockroach✓
• B. Earthworm
• C. Human
• D. Planaria
• E. Hydra

Explanation: The correct answer is cockroach, as they possess Malpighian tubules for excretion. These tubules convert nitrogenous waste into uric acid, suitable for terrestrial environments. Other animals listed, such as earthworms, humans, planaria, and hydra, utilize different excretory mechanisms. Earthworms have nephridia, humans have kidneys, planaria use flame cells, and hydra rely on diffusion.

Q19. Growth movement caused in response to gravitational stimulus is called:

• A. Nutation
• B. Geotropism✓
• C. Nastic movement
• D. Tropic movement
• E. Turgor movement

Explanation: Geotropism is the growth movement of plants in response to gravity. It is a type of tropism where roots usually demonstrate positive geotropism by growing towards the gravitational pull, while shoots display negative geotropism by growing away from it. Other options such as nutation, nastic movement, and turgor movement involve responses to different stimuli and mechanisms. Tropic movement is a general term for directional growth responses, and geotropism is a specific subset of this category.

Q20. A psychological condition usually seen in girls and young women, with loss of appetite, is:

• A. Obesity
• B. Malnutrition
• C. Anorexia Nervosa✓
• D. Dyspepsia
• E. Peptic ulcer

Explanation: Anorexia nervosa is a psychological disorder primarily affecting girls and young women, characterized by an intense fear of gaining weight and a distorted body image, leading to severe food intake restriction and loss of appetite. Unlike the other conditions listed, anorexia is specifically psychological and affects the demographic in question. Obesity is more about excessive weight gain, malnutrition is a broad term for nutrient deficiencies, dyspepsia is a digestive issue, and peptic ulcers are physical conditions of the digestive system.

Q21. Haemoglobin carries more oxygen than plasma by:

• A. 50 times
• B. 20 times
• C. 70 times✓
• D. 100 times

Explanation: Hemoglobin significantly enhances the oxygen-carrying capacity of blood by approximately 70 times compared to plasma. Hemoglobin, found in red blood cells, binds and transports oxygen efficiently, with each gram carrying about 1.34 mL of oxygen. Given the typical hemoglobin concentration of 15 g/dL in blood, this results in roughly 20 mL of oxygen per 100 mL of blood, far surpassing the minimal oxygen dissolved in plasma.

Q22. Bones of the skull are joined by:

• A. Fibrous joints✓
• B. Sliding joints
• C. Pivot joints
• D. Hinge joints
• E. Gliding joints

Explanation: Fibrous joints are characterized by being immovable and are primarily found in the skull, where they are known as sutures. These joints provide stability and protection for the brain by holding the skull bones firmly together. Other joint types, such as sliding, pivot, hinge, and gliding joints, allow varying degrees of movement and are not suitable for the protective function required by the skull.

Q23. Cytoplasmic localization is a consequence of:

• A. Fertilization
• B. Cleavage✓
• C. Morula
• D. Blastula

Explanation: Cytoplasmic localization is a consequence of cleavage. Cleavage, in the context of embryology and development, refers to a series of rapid and successive cell divisions that occur in the early stages of the development of a multicellular organism, typically following fertilization. These cell divisions are essential for the formation of a multicellular structure from a single-celled zygote and give rise to a cluster of smaller, undifferentiated cells called blastomeres.Cleavage sets the stage for subsequent stages of embryonic development, including gastrulation, organogenesis, and differentiation.

Q24. Highly condensed portions of the chromatin are called:

• A. Heterochromatin✓
• B. Nucleosome
• C. Super coils
• D. None of these

Explanation: Heterochromatin represents the highly condensed portions of chromatin. This dense packing makes the DNA inaccessible to the transcription machinery, leading to a transcriptionally inactive state. In contrast, euchromatin is less condensed and allows for active gene transcription. Nucleosomes are the structural units of chromatin, and supercoiling refers to the additional twisting of the DNA helix to aid in its compaction, not its condensation state. Therefore, heterochromatin is the best answer to describe highly condensed chromatin.

Q25. The disease in which patients passed urine that rapidly turned black on exposure to air is called:

• A. Phenylketonuria
• B. Alkaptonuria✓
• C. Sickle cell anemia
• D. Hemophilia
• E. Anuria

Explanation: Alkaptonuria is an inherited condition that results in the buildup of homogentisic acid, causing urine to turn black upon exposure to air. This distinctive symptom differentiates it from other disorders. Phenylketonuria involves amino acid metabolism but does not affect urine color. Sickle cell anemia and hemophilia are blood disorders, not related to urine. Anuria is the absence of urine production, not a change in color.

Q26. Diplotene is the sub-stage of:

• A. Anaphase
• B. Telophase I
• C. Prophase I✓
• D. Metaphase
• E. All of these

Explanation: Prophase I of meiosis is divided into five distinct sub-stages: leptotene, zygotene, pachytene, diplotene, and diakinesis. Diplotene is the fourth sub-stage, where homologous chromosomes start to separate slightly but remain connected at chiasmata, allowing for genetic recombination. This stage is unique to prophase I and does not occur in other phases such as anaphase, telophase I, or metaphase, which are distinct phases with specific roles in chromosome alignment and separation. Therefore, the correct answer is Prophase I.

Q27. Deficient production of hormones by adrenal glands results in:

• A. Cushing's syndrome
• B. Addison's disease✓
• C. Diabetes Mellitus
• D. Goiter
• E. Epilepsy

Explanation: Addison's disease is the result of insufficient production of hormones from the adrenal glands, particularly cortisol and aldosterone. This condition leads to symptoms such as fatigue, muscle weakness, and low blood pressure. Cushing's syndrome, in contrast, is caused by excessive cortisol. Diabetes Mellitus involves insulin issues and not adrenal hormones. Goiter relates to thyroid gland issues, and epilepsy is a neurological disorder, both unrelated to adrenal insufficiency.

Q28. All of the following are sexually transmitted diseases except:

• A. Syphilis
• B. Gonorrhea
• C. Alzheimer's disease✓
• D. Genital herpes
• E. AIDS

Explanation: Alzheimer's disease is not a sexually transmitted disease. It is a progressive neurodegenerative disorder unrelated to sexual activity, primarily influenced by genetic and age-related factors. In contrast, syphilis, gonorrhea, genital herpes, and HIV/AIDS are all conditions that are transmitted through sexual contact. Identifying Alzheimer's disease as the exception is key to answering this question correctly.

Q29. The producers of pond ecosystem include:

• A. Bacteria
• B. Zooplankton
• C. Fungi
• D. Phytoplankton✓
• E. All of these

Explanation: Phytoplankton are the main producers in a pond ecosystem because they perform photosynthesis, producing oxygen and organic matter that sustains other aquatic organisms. While some bacteria, like cyanobacteria, can also photosynthesize, they play a minor role compared to phytoplankton. Zooplankton are primarily consumers, and fungi are decomposers, not producers. Therefore, 'Phytoplankton' is the correct answer.

Q30. Erythroblastosis foetalis occurs when:

• A. Mother is Rh-positive and Baby is Rh-negative
• B. Mother is Rh-negative and the Baby is Rh-positive✓
• C. Both Mother and Baby are Rh-negative
• D. Both Mother and Baby are Rh-positive
• E. All of the above statements are true

Explanation: Erythroblastosis fetalis occurs when an Rh-negative mother carries an Rh-positive fetus. The mother's immune system may recognize the Rh-positive red blood cells of the fetus as foreign and produce antibodies against them, leading to hemolysis. This condition typically arises during a second pregnancy, after the mother has been sensitized by a previous Rh-positive pregnancy. Options A, C, and D are incorrect because they describe scenarios where there is no Rh incompatibility. Option E is also incorrect as it incorrectly suggests that all scenarios could result in erythroblastosis fetalis, which is not the case.

Q31. Amniocentesis is performed between:

• A. 16th and 18th week of gestation✓
• B. 1st and 2nd week of gestation
• C. 30th and 32nd week of gestation
• D. 37th and 38th week of gestation
• E. After the delivery of the baby

Explanation: Amniocentesis is a prenatal diagnostic procedure performed between the 16th and 18th weeks of gestation. This timing ensures there is enough amniotic fluid for sampling, which is critical for analyzing the genetic health of the fetus. Performing amniocentesis earlier, such as in the 1st or 2nd week, is not feasible due to insufficient amniotic fluid. Later stages, such as the 30th week onwards, are not ideal for this procedure as the primary aim is to diagnose potential issues earlier in the pregnancy. Conducting this procedure post-delivery is impossible as it is specifically a prenatal test.

Q32. Theory of Lamarck was based on:

• A. Adaptive modifications✓
• B. Adaptive radiations
• C. Both A and B
• D. None of the above

Explanation: Lamarckism is the theory proposed by Jean-Baptiste Lamarck suggesting that organisms can acquire new characteristics during their lifetime due to environmental pressures and that these acquired traits can be passed to their offspring. This concept is known as adaptive modifications and emphasizes individual organism changes rather than species-wide diversification like adaptive radiations. Therefore, the correct answer is Option A, which highlights the core principle of Lamarck's theory. Options B and C are incorrect because they involve ideas that are not part of Lamarckism, such as adaptive radiations. Option D is incorrect because Lamarck's theory is indeed based on adaptive modifications.

Q33. In the pea plants, the factors round and yellow seeds (RRYY) is dominant over wrinkled and green seeds (rryy). Keeping this in mind, identify the seed that has the genotype round and green.

• A. RRyy✓
• B. rrYy
• C. RrYy
• D. RRYy

Explanation: The genotype RRyy produces round and green seeds. The 'RR' indicates the presence of the dominant trait for round seeds, while 'yy' indicates the recessive trait for green seeds. Other options either contain the recessive 'rr' indicating wrinkled seeds or 'YY' or 'Yy' indicating yellow seeds, which does not match the requirement for round and green seeds.

Q34. Chicken pox is caused by:

• A. Hepatitis A virus
• B. Varicella zoster virus✓
• C. Influenza virus
• D. HIV

Explanation: Chickenpox (varicella) is an infectious disease caused by the vancella zoster virus (VZV), a member of the herpesvirus family. The virus leads to an itchy rash and fluid-filled blisters, typically in children. The same virus can reactivate later in life as shingles.

Q35. Lysosomes function in:

• A. Protein synthesis
• B. Processing of cellular materials
• C. Intracellular digestion✓
• D. Lipid synthesis
• E. Carbohydrate synthesis

Explanation: Lysosomes are specialized organelles within the cell that contain hydrolytic enzymes capable of breaking down macromolecules like proteins, nucleic acids, lipids, and carbohydrates. Their primary function is intracellular digestion, where they degrade and recycle cellular waste, damaged organelles, and material ingested by the cell. Unlike ribosomes, lysosomes do not synthesize proteins, and they are not involved in lipid or carbohydrate synthesis, which occur in other organelles. Options such as 'protein synthesis', 'lipid synthesis', and 'carbohydrate synthesis' refer to processes that take place outside of lysosomes, highlighting their specialized role in cellular maintenance through digestion.

Q36. The viruses are:

• A. Cellular
• B. Prokaryotes
• C. Non-cellular✓
• D. Eukaryotes
• E. Visible with naked eye

Explanation: Viruses are classified as non-cellular because they lack the cellular structures that define living cells, such as a cell membrane, cytoplasm, and organelles. Instead, they consist of genetic material (either DNA or RNA) surrounded by a protein coat called a capsid. Unlike cellular organisms, viruses cannot perform metabolic processes or reproduce on their own; they must infect a host cell to replicate. This distinguishes them from cellular life forms, including prokaryotes and eukaryotes.Option A (Cellular) is incorrect because viruses do not have the structures that define cellular life. Option B (Prokaryotes) is incorrect because viruses do not fit the definition of prokaryotic cells, which have a cell membrane and cytoplasm. Option D (Eukaryotes) is incorrect because viruses do not have the complex structures found in eukaryotic cells. Option E (Visible with naked eye) is incorrect because viruses are too small to be seen without specialized equipment.

Q37. Bacterial pilli help in:

• A. Locomotion
• B. Conjugation✓
• C. Phagocytosis
• D. Pinocytosis
• E. Exocytosis

Explanation: Bacterial pili, specifically conjugative pili, are primarily involved in the process of conjugation, which is a method of horizontal gene transfer among bacteria. This process allows bacteria to exchange genetic material, increasing genetic diversity. While flagella are responsible for bacterial locomotion, processes like phagocytosis, pinocytosis, and exocytosis are related to the transport of materials into or out of cells and are not functions of pili.

Q38. Trypanosoma belongs to the class:

• A. Sarcodina
• B. Flagellata✓
• C. Ciliata
• D. Suctoria
• E. Sporozoa

Explanation: Trypanosoma belongs to the class Flagellata because it uses flagella for movement. This class is distinct from others like Sarcodina, which rely on pseudopodia, and Ciliata, which have cilia. Suctoria are parasitic and attach to hosts without flagella, while Sporozoa are non-motile and reproduce via spores. Understanding these differences helps in categorizing Trypanosoma correctly under Flagellata

Q39. A bacteriophage consists solely of:

• A. DNA and protein✓
• B. RNA and protein
• C. RNA only
• D. Protein only
• E. DNA only

Explanation: Bacteriophages are viruses that infect bacteria. They are primarily composed of DNA and protein. The DNA serves as the genetic material, and the protein coat protects the DNA and facilitates the infection of bacterial cells. While some bacteriophages have RNA instead of DNA, these are less common. Options such as RNA only, protein only, or DNA only do not accurately describe the typical structure of a bacteriophage, which relies on both genetic material and a protein coat for function and survival.

Q40. Which of the following factors affect enzyme activity?

• A. Temperature
• B. pH
• C. Concentration of substrate
• D. Radiation
• E. All of these✓

Explanation: All of these factors can influence enzyme activity:Temperature: Enzymes generally work faster with rising temperatures until they reach an optimum point. Beyond this, high temperatures can cause denaturation.pH: Each enzyme has an optimal pH range. Deviations from this range can alter the enzyme's shape and reduce its efficiency.Concentration of substrate: Increasing substrate concentration can boost reaction rates up to a point of saturation.Radiation: While not typically considered an immediate factor, radiation can cause oxidative damage to enzymes, impeding their function.Thus, all these factors are relevant, making Option E the correct choice. Options A, B, C, and D describe individual factors, but only 'All of these' encompasses the full scope of influences on enzyme activity.

Q41. Which of the following statements is true for Amorphous solids?

• A. They possess symmetry
• B. They are isotropic✓
• C. They are anisotropic
• D. They cleave along a particular direction
• E. They have a definite shape

Explanation: Amorphous solids are isotropic because their lack of long-range order results in uniform physical properties in all directions. This is in contrast to crystalline solids, which are anisotropic due to their orderly atomic structure. Amorphous solids do not possess symmetry and cannot cleave along particular planes because their particles are randomly arranged. Additionally, they do not exhibit a definite shape as their molecular structure does not form a regular lattice.

Q42. Which of the following statements is correct?

• A. Faraday's experiments proved the existence of electrons
• B. Crookes tube experiment demonstrated the presence of electrons in the atoms
• C. Radioactivity directly confirms the presence of electrons and protons
• D. Chadwick's experiment confirmed the presence of neutrons✓

Explanation: Option D is correct. James Chadwick's experiment involving the bombardment of beryllium with alpha particles led to the discovery of neutrons, neutral particles with a mass similar to that of protons. These particles do not have an electric charge, which distinguishes them from protons and electrons. The other options are incorrect because Faraday's work did not directly involve electrons, Crookes' experiment did not reveal protons, and radioactivity does not directly confirm the presence of electrons and protons.

Q43. A term in which no two electron can have the same set of four Quantum numbers is stated by

• A. Heisenberg's principle
• B. Pauli's exclusion principle✓
• C. Aufbau principle
• D. Hund's rule

Explanation: The heisenberg uncertainty principle states that certain pairs of physical properties, such as position and momentum, cannot be precisely determined simultaneously with arbitrary accuracy. Mathematically, the uncertainty principle is expressed as follows: (Δx . Δp ≥ h/4π) Hence, this is the incorrect answer. This is the correct answer because, The Pauli exclusion principle states that each electron in an atom must have a unique combination of quantum numbers. The four quantum numbers that describe an electron are: The principal quantum number (n) which determines the energy level or shell of the electron. The azimuthal quantum number (l) which specifies the subshell or orbital angular momentum of the electron. The magnetic quantum number (mₗ) which specifies orientation in space of a given orbital of particular energy and shape. The spin quantum number (mₛ) which specifies the spin state of an electron. The Aufbau principle, also known as the "building-up principle". According to the Aufbau principle, electrons occupy the lowest energy orbitals available first before moving to higher energy levels. The principle is based on the idea that electrons exist in discrete energy levels or shells surrounding the nucleus of an atom. Hence, this is the incorrect answer. Hund's rule states that when electrons are filling degenerate orbitals (orbitals with the same energy), they will occupy separate orbitals within the subshell before pairing up. In other words, electrons will try to maximize the number of unpaired electrons in a subshell or orbital before pairing begins. This principle is based on the concept of electron-electron repulsion. Hence, this is the incorrect answer.

Q44. Which of the following molecules have zero Dipole Moment?

• A. CCl4
• B. CO2
• C. Cl2
• D. C6H6
• E. All of the above✓

Explanation: All the molecules listed have a zero dipole moment due to their symmetrical structures:CCl4: Although it has polar C-Cl bonds, the tetrahedral symmetry results in a net dipole moment of zero.CO2: The linear shape with two opposing C=O bonds results in the cancellation of dipole moments.Cl2: As it consists of identical atoms, no dipole moment arises.C6H6 (Benzene): The planar symmetrical structure leads to the cancellation of dipole moments of C-H bonds.Therefore, the correct answer is 'All of the above'.

Q45. Bond energy:I. is the energy required to break a bond between two atoms in a diatomic molecule II. Is taken as the energy released in forming a bond form free atoms III. Is the measure of the strength of bond.

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

Explanation: Bond energy is a critical concept in understanding chemical bonding and is defined through multiple perspectives:Option I: It is indeed the energy required to break a bond between two atoms in a diatomic molecule, indicating how much energy is needed to overcome the bond's strength.Option II: The energy released when a bond is formed from free atoms is also a measure of bond energy, showing the stabilization energy provided during bond formation.Option III: Bond energy serves as an indicator of bond strength; stronger bonds require more energy to break, thus having higher bond energies.Therefore, all three options collectively provide a comprehensive understanding of bond energy, making Option E the correct choice. Each statement highlights a different but related aspect of bond energy, and understanding this concept requires integrating all perspectives.

Q46. The oxidation number of Nitrogen in HNO3 is:

• A. +4
• B. +2
• C. +6
• D. +5✓
• E. +7

Explanation: In HNO₃, hydrogen is +1 and each oxygen is –2. Total must equal zero: +1+x+3(−2)=0. Solving gives x=+5, so nitrogen has oxidation number +5.

Q47. A certain chemical reaction follows thefollowing rate law: Rate =K [A] [B]2 The order of reaction is:

• A. 1
• B. 2
• C. 3✓
• D. 4
• E. 5

Explanation: The order of a reaction is determined by summing the exponents of the concentration terms in the rate law. In the given rate law, Rate = K [A] [B]2, the exponent of [A] is 1, and the exponent of [B] is 2. Thus, the overall order of the reaction is 1 + 2 = 3. Option C is correct. The other options are incorrect because they do not correctly sum the exponents in the rate equation.

Q48. Only two elements are present in:

• A. Period 1✓
• B. Period 2
• C. Period 3
• D. Period 4
• E. Period 5

Explanation: Period 1 of the periodic table consists of only two elements: hydrogen and helium. This is because the first electron shell (the 1s orbital) can hold a maximum of two electrons. In contrast, Periods 2 and 3 each have 8 elements, as they include the filling of s and p orbitals. Periods 4 and 5 have even more elements, 18 each, due to the inclusion of the d orbitals. Hence, the correct answer is Period 1, where only two elements are present.

Q49. The unit of rate of reaction is:

• A. Mole (dm3) sec
• B. Mole (dm3) sec-1
• C. Mole(dm-3) sec -1✓
• D. Mole(dm3) sec-2
• E. Mole (dm3)-1 sec -2

Explanation: Reaction rates are usually expressed as the concentration of reactant consumed or the concentration of product formed per unit time. The units are thus moles per decimeter cube per unit time [Mole (dm-3) sec-1 ].

Q50. Hydrides which are prepared by passing hydrogen gas over hot alkali metals or alkaline earth metals are called:

• A. Covalent hydrides
• B. Ionic hydrides✓
• C. Complex hydrides
• D. Metallic hydrides
• E. Polymeric hydrides

Explanation: The correct answer is Ionic hydrides. Ionic hydrides are formed when hydrogen gas is passed over hot alkali or alkaline earth metals (except Be and Mg). In this reaction, the metal donates electrons to hydrogen, resulting in a compound with ionic properties. These hydrides are typically white crystalline solids that react with water to release hydrogen gas.Covalent hydrides involve electron sharing with non-metals, which is not the case here. Complex hydrides involve more complex combinations of elements and are not formed by the simple interaction described. Metallic hydrides involve transition metals and are formed by hydrogen absorption into metal lattices, not applicable here. Polymeric hydrides involve hydrogen bonding in networks, not relevant to this reaction.

Q51. When Gypsum is heated to about 100° C, it losses some water of crystallization and becomes:

• A. Epsom salt
• B. Kieserite
• C. Plaster of Paris✓
• D. Bleaching Powder
• E. Caustic soda

Explanation: When gypsum (calcium sulfate dihydrate) is heated to approximately 373 K (100°C), it loses part of its water of crystallization, resulting in the formation of calcium sulfate hemihydrate, commonly known as Plaster of Paris. This transformation is unique to gypsum and its chemical composition. The other options, such as Epsom salt, kieserite, bleaching powder, and caustic soda, are chemically distinct and do not undergo similar transformations when heated. Epsom salt and kieserite are magnesium-based compounds, while bleaching powder and caustic soda are used for entirely different purposes.

Q52. The chemical properties of Sulphuric Acid is/are:

• A. Acidic properties
• B. Oxidizing properties
• C. Dehydrating properties
• D. Sulfonating properties
• E. All of these✓

Explanation: Sulfuric acid is a multi-functional chemical with a range of properties:Acidic properties: As a strong acid, sulfuric acid dissociates completely in water, releasing H+ ions, which are responsible for its acidic nature.Oxidizing properties: In redox reactions, sulfuric acid can act as an oxidizing agent, accepting electrons from other substances.Dehydrating properties: Sulfuric acid can remove water from other compounds, a process evident in its interactions with organic materials like carbohydrates.Sulfonating properties: Its ability to add sulfonate groups to organic compounds is crucial for producing sulfonated derivatives.Therefore, the correct answer is All of these, as sulfuric acid exhibits all these chemical properties. Each of the individual options represents just one aspect of its chemical behavior.

Q53. Complete the following equation:Al+ dilute H2SO4

• A. Al2(SO4)3 + H2O
• B. Al2(SO4)3 + H2✓
• C. Al2(SO4)3 + H2O + SO2
• D. Al2(SO4)3 + H2 + SO2
• E. None of these

Explanation: The reaction between aluminum (Al) and dilute sulfuric acid (H2SO4) forms aluminum sulfate (Al2(SO4)3) and hydrogen gas (H2). The balanced equation for the reaction is:2Al + 3H2SO4 → Al2(SO4)3 + 3H2Option B correctly represents this equation. Option A is incorrect because it suggests that water is produced instead of hydrogen gas. Options C and D incorrectly suggest that sulfur dioxide is a product, which is not the case. Option E is incorrect because there is a correct option provided.

Q54. The electronic configuration of iron is:

• A. 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d5
• B. 1s2, 2s2, 2p6, 3s2, 3p6, 4s1, 3d5
• C. 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d6✓
• D. 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d3
• E. 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d2

Explanation: The electronic configuration of iron (Fe) with 26 electrons is: 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d6. This follows the Aufbau principle, where electrons fill orbitals starting from the lowest energy level. The 4s subshell is filled before the 3d subshell. Options A, B, D, and E account for fewer electrons than iron's 26, each missing one or more electrons in their configuration.

Q55. The chemical name of the baking soda is:

• A. Sodium carbonate
• B. Sodium bicarbonate✓
• C. Sodium chloride
• D. Sodium hydroxide
• E. Both B and C

Explanation: The correct answer is Sodium bicarbonate. Sodium bicarbonate, also known as baking soda, is a chemical compound used primarily as a leavening agent in baking. It reacts with acids to produce carbon dioxide gas, which causes dough to rise. The other options are incorrect: sodium carbonate is used in cleaning and water softening, sodium chloride is table salt, and sodium hydroxide is a caustic substance used in cleaning and manufacturing.

Q56. IUPAC Nomenclature of: CH3 - CH = CH - CH2 - CH = CH2 is:

• A. 2 - pentene
• B. 1, 4 - hexadiene✓
• C. 3 - methyl butane
• D. 1, 3, 5 - heptatriene
• E. 1, 3, 6 - hexatriene

Explanation: The correct IUPAC name for the compound CH3 - CH = CH - CH2 - CH = CH2 is 1,4-hexadiene. This is because the compound has a longest chain of 6 carbon atoms, indicated by the prefix 'hex'. The double bonds are located at the first and fourth carbon atoms, which is specified in the name as 1,4-diene. The other options are incorrect because they either miscount the number of carbon atoms, suggest incorrect branching, or provide inappropriate locations for the double bonds.

Q57. Benzene can be prepared from:

• A. From Petroleum
• B. From Coal
• C. From Acetylene
• D. From Phenol
• E. All of these✓

Explanation: The correct answer is that benzene can be prepared from all the mentioned sources. Petroleum: Benzene is obtained through catalytic reforming and steam cracking of naphtha, which are standard industrial processes for hydrocarbon refinement. Coal: During the carbonization of coal, benzene is one of the volatile compounds distilled from coal tar. Acetylene: Acetylene undergoes cyclic polymerization at high temperatures, forming benzene as a result. Phenol: Reduction of phenol using zinc dust is another chemical method to synthesize benzene, with zinc oxide as a byproduct. Thus, each method demonstrates a valid approach to benzene production.

Q58. The electrophilic reactions of Benzene are:

• A. Halogenation
• B. Nitration
• C. Sulphonation
• D. Alkylation and Acylation
• E. All of these✓

Explanation: Electrophilic substitution reactions of benzene involve the replacement of a hydrogen atom on the benzene ring with an electrophile. The listed reactions—halogenation, nitration, sulphonation, and Friedel-Crafts alkylation and acylation—are all examples of this process:Halogenation: Benzene reacts with halogens in the presence of a Lewis acid to form aryl halides.Nitration: Involves the substitution of a hydrogen atom by a nitronium ion to form nitrobenzene.Sulphonation: Benzene reacts with fuming sulfuric acid, introducing a sulfonyl group.Friedel-Crafts Alkylation and Acylation: Substitution of a hydrogen atom by an alkyl or acyl group with the help of a Lewis acid catalyst.All these reactions are characterized by the generation of an electrophile that attacks the π-electron-rich benzene ring, substituting one of the hydrogen atoms. Therefore, the correct answer is 'All of these.'

Q59. ROR is the general formula of:

• A. Alcohols
• B. Esters
• C. Cyanides
• D. Ethers✓
• E. Aldehydes

Explanation: The general formula ROR is indicative of ethers, which consist of two alkyl or aryl groups linked by an oxygen atom. This structure is distinct from the other options: Alcohols (ROH) feature a hydroxyl group, Esters (R-COO-R') include a carbonyl bonded to an alkoxy group, Cyanides (RCN) contain a cyano group, and Aldehydes (RCHO) have a carbonyl group bonded directly to a hydrogen atom, differentiating them from ethers.

Q60. Primary Alcohol is produced by reactions of Grignard's reagent with _ followed by hydrolysis in an acidic medium.

• A. Carbon dioxide
• B. Formaldehyde✓
• C. Acetaldehyde
• D. Ketone
• E. Methyl chloride

Explanation: The Grignard Reaction involves the addition of an organomagnesium halide (Grignard reagent) to carbonyl compounds. When Grignard reagents react with formaldehyde, a primary alcohol is produced upon hydrolysis in an acidic medium. Formaldehyde is unique as it is the simplest aldehyde, thus allowing the formation of a primary alcohol. Other aldehydes and ketones lead to secondary and tertiary alcohols, respectively. Carbon dioxide reacts with Grignard reagents to form carboxylic acids, not alcohols, and methyl chloride does not react to form an alcohol.

Q61. An ester is prepared by the reaction of:

• A. Two alcohols
• B. Carboxylic acid and alcohol✓
• C. Ketone and alcohol
• D. Aldehyde and alcohol
• E. All of these

Explanation: When a carboxylic acid is treated with an alcohol and an acid catalyst, an ester is formed (along with water):

Q62. Which of the following acids is used for etching glass?

• A. Hydrochloric Acid
• B. Nitric Acid
• C. Hydrofluoric Acid✓
• D. Sulphuric Acid
• E. Acetic Acid

Explanation: Hydrofluoric Acid (HF) is used for etching glass because it reacts with silicon dioxide (SiO2), the main component of glass, to form gaseous silicon tetrafluoride (SiF4) and water. This reaction effectively removes material from the glass surface, creating an etched pattern. The other acids listed, such as hydrochloric, nitric, sulphuric, and acetic acids, do not react with silicon dioxide and therefore cannot etch glass.

Q63. By heating 25g of limestone (CaCO3) , the weight of carbon dioxide produced is:

• A. 14 g
• B. 71 g
• C. 11 g✓
• D. 2 g
• E. 10 g

Explanation: Limestone is primarily composed of calcium carbonate (CaCO3). When heated, it decomposes according to the reaction:CaCO3 --> CaO + CO2From the stoichiometric relationship, 100g of CaCO3 decomposes to produce 44g of CO2. Therefore, for 25g of CaCO3, the amount of CO2 produced is calculated as follows:(25g CaCO3 / 100g CaCO3) * 44g CO2 = 11g CO2Thus, the correct answer is 11g. Other options either overestimate or underestimate this calculated mass based on incorrect stoichiometric assumptions.

Q64. A child's balloon has a volume 3.80 dm3, when the temperature is 35°C. If the balloon is put in a refrigerator and cooled to 5°C, the approximate volume of the balloon is (assume pressure inside the balloon is equal to atmospheric pressure):

• A. 3.00 dm3
• B. 3.43 dm3✓
• C. 3.08 dm3
• D. 3.25 dm3
• E. 0.54 dm3

Explanation: To solve this, we apply Charles's Law, which states that at constant pressure, the volume of a gas is directly proportional to its temperature in Kelvin. Start by converting the given temperatures from Celsius to Kelvin: T1 = 35°C + 273 = 308 K and T2 = 5°C + 273 = 278 K. Using the formula V1/T1 = V2/T2, we have:3.80 dm3 / 308 K = V2 / 278 K.Solving for V2 gives:V2 = (3.80 dm3 * 278 K) / 308 K = 3.43 dm3.Thus, the correct answer is 3.43 dm3. The other options either miscalculate the proportional change or do not apply Charles's Law correctly.

Q65. If the matter in a given system at a given condition is divided into two equal parts, then the value of the extensive properties will become:

• A. Double of the original value
• B. Half of the original value✓
• C. Remain the same as the original value
• D. One-fourth of the original value
• E. Heat of formation

Explanation: Extensive properties in thermodynamics, such as mass, volume, and energy, directly depend on the quantity of matter present. When the matter is divided into two equal parts, each part retains half of the original extensive property value. Intensive properties, on the other hand, such as temperature and density, do not change with the amount of matter and remain constant. Thus, the correct answer is that the value of extensive properties will become half of the original value. Option A is incorrect because doubling would imply an increase, which doesn't happen upon division. Option C is incorrect because it applies to intensive properties, not extensive ones. Option D is incorrect because dividing into two equal parts results in half, not one-fourth. Option E is irrelevant as it refers to a specific thermodynamic property unrelated to the division of matter.

Q66. The study of measurement of heat absorbed or given out in a chemical reaction is referred to as:

• A. Endothermic reaction
• B. Exothermic reaction
• C. Thermochemistry✓
• D. Heat of formation

Explanation: Thermochemistry is the branch of chemistry that deals with the measurement and analysis of heat energy changes in chemical processes and physical transformations. It encompasses both exothermic and endothermic reactions, providing a broad framework for understanding heat changes.Endothermic reactions focus on heat absorption, while exothermic reactions focus on heat release, making them specific types of reactions within the broader scope of thermochemistry.The heat of formation is a specific thermochemical concept related to the formation of compounds from elements, but it doesn't cover the general measurement of heat in reactions.

Q67. In a reaction:A+B < - > 2C When equilibrium was attained, the concentration was [A] = [B] = 4 moles/dm3[C]= 6 moles/dm3The equilibrium constant Kc of this reaction is:

• A. 1.25
• B. 2.25✓
• C. 3.25
• D. 2.75
• E. 3.75

Explanation: The equilibrium constant Kc is calculated using the expression: Kc = [C]² / [A][B]. For the reaction A + B < - > 2C, substitute the equilibrium concentrations: [C] = 6 moles/dm3, [A] = [B] = 4 moles/dm3. Thus, Kc = (6)² / (4)(4) = 36 / 16 = 2.25, confirming Option B as correct. Options A, C, D, and E result from errors in calculation or misinterpretation of the equilibrium constant formula.

Q68. If the initial ratio of products to reactants(the reaction quotient) is greater than the Kc then:

• A. The reaction will shift towards the reverse direction.✓
• B. More quantity of products is obtained.
• C. The ratio increases to the value of Kc.
• D. Equilibrium has been attained.
• E. There is no shifting of reaction.

Explanation: If the reaction quotient Q > Kc , there are too many products compared to equilibrium. To reduce Q back to Kc , the system shifts toward reactants (reverse direction). Thus, the reaction moves backward until equilibrium is restored.

Q69. Aqueous solution of Na2CO3 is:

• A. Acidic
• B. Alkaline✓
• C. Both Acidic and Alkaline
• D. Neutral
• E. None of these

Explanation: Sodium carbonate (Na2CO3), commonly known as washing soda, dissociates in water to form sodium ions (Na+) and carbonate ions (CO32-). The carbonate ions react with water to produce hydroxide ions (OH-), making the solution alkaline.Option A is incorrect because an acidic solution would release H+ ions, which Na2CO3 does not. Option C is incorrect because a solution cannot be both acidic and alkaline at the same time. Option D is incorrect because a neutral solution has a pH of 7, which is not the case here. Option E is incorrect as the correct answer is that the solution is alkaline.

Q70. Which of the following is TRUE regarding Methyl Alcohol?

• A. It is a colorless, volatile, thin liquid with specific gravity 0.796 at 15°C.✓
• B. It is used for low-temperature thermometers and as a fuel substitute.
• C. It is extensively used in the formation of different beverages.
• D. It is used as a base for perfumes.
• E. It is used as an antiseptic and disinfectant.

Explanation: Methyl Alcohol, also known as methanol, is a colorless, volatile, and thin liquid with a specific gravity of 0.796 at 15°C. This makes Option A the correct choice. Methyl Alcohol is primarily used as an industrial solvent and antifreeze, and is not suitable for consumption or use in perfumes due to its toxicity. Options B and C describe Ethanol, which is used in thermometers and beverages. Option D describes esters, often used in perfumes. Option E describes Phenol, which is used as an antiseptic and disinfectant.

Q71. A car starts from rest and moves with a constant acceleration. During the 5th second of its motion, it covers a distance of 36 meters. What is the acceleration of the car?

• A. 12.5 m/s2
• B. 8 m/s2✓
• C. 15 m/s2
• D. 16 m/s2
• E. 14 m/s2
• F. 2.88 m/s2

Explanation: You will find the distance traveled in 5 and 4 seconds individually. After subtracting these two terms and equating it to 36 meters, all variables are fulfilled other than a which we can solve for.In the below equations, s is distance, a is acceleration, and t is time.In 4 seconds, the truck covers:s = 1/2 at2s = 1/2 (a) 42s = 1/2 (a) (16)s = 8 (a) metersIn 5 seconds, the truck coverss = 1/2 a t2s = 1/2 (a) 52s = 1/2 (a) 25s = 12.5 (a) metersThe distance covered in 5 seconds minus the distance covered in 4 seconds is the distance (36 meters) covered in the 5th second.36 = 12.5 a - 8 a36 meters = 4.5 seconds2 (a)a = acceleration = 8 m/s2

Q72. Law of conservation of momentum states that:I. there is no external force applied to a system, then the total momentum of that system remains constant II. if there is an external force applied to a system, then the total momentum of that system remains constant III. if there is no external force applied to a system, then the total momentum of that system keeps changing

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

Explanation: If there is no external force applied to the system, then the total momentum of that system remains constant. If an external force is applied then the total momentum will change.The law of conservation of momentum states that, for two or more bodies in an isolated system acting upon each other, their total momentum remains constant unless an external force is applied. Therefore, momentum can neither be created nor destroyed and will stay constant.

Q73. Projectile must be launched at which angle with the horizontal to attain maximum range?

• A. 90 degrees
• B. 45 degrees✓
• C. 75 degrees
• D. 105 degrees
• E. 145 degrees

Explanation: To achieve maximum range, a projectile should be launched at an angle of 45 degrees with the horizontal. This angle provides the ideal balance between vertical and horizontal components of velocity, maximizing the distance traveled horizontally. The formula R = (v^2 sin2θ)/g confirms that maximum range occurs when sin2θ equals 1, which happens at θ = 45 degrees. Other angles, such as 90 degrees, result in no horizontal range, while angles greater than or less than 45 degrees reduce the range due to an imbalance in velocity components.

Q74. A player throws a ball at an initial velocity of 36 m/second. The maximum distance the ball can reach (assume the ball is caught at the same height at which it was released) is:

• A. 146 m
• B. 130 m
• C. 132 m✓
• D. 129 m
• E. 145 m

Explanation: The maximum range of a projectile is achieved when it is launched at an angle of 45 degrees to the horizontal. The formula for the range is given by R = u2 sin(2θ) / g, where u is the initial velocity and g is the acceleration due to gravity (approximately 9.8 m/s²).For this problem, the initial velocity u is 36 m/s, and the angle θ is 45 degrees. Plugging these values into the formula gives:R = (36)2 sin(90°) / 9.8 = 1296 / 9.8 ≈ 132.2 mThis confirms that the correct answer is approximately 132 m, making Option C the right choice. Other options either overestimate or underestimate the range due to incorrect calculations or assumptions.

Q75. What forms the basis of DNA fingerprinting?

• A. The relative proportions of purines and pyrimidines in DNA
• B. The relative difference in the DNA occurrence in blood, skin, and saliva
• C. The relative amount of DNA in the ridges and grooves of the fingerprints
• D. Satellite DNA occurring as highly repeated, short DNA segments✓

Explanation: DNA fingerprinting is a technique of determining nucleotide sequences of certain areas of DNA which are unique to each individual. The difference of about 0.1% or 3 × 106 base pairs (out of 3 × 10 9 bp) provides individuality to each human being. The human genome possesses numerous small noncoding but inheritable sequences of bases that are repeated many times. These sequences occur near telomere, centromeres, Y chromosome, and heterochromatic area. The area with the same sequence of bases repeated several times is called repetitive DNA. It is separated as a satellite from the bulk DNA during density gradient centrifugation and hence called satellite DNA where repetition of the bases is in tandem. Satellite DNAs show polymorphism (the occurrence of mutations in a population at high frequency), which is the basis of genetic mapping of human genome as well as DNA fingerprinting. While mutations in genes produce alleles with different expressions, mutations in noncoding repetitive DNA have no immediate impact. These mutations which have piled up with time form the basis of polymorphism.

Q76. A 70 kg man runs up a hill through a height of 3 meters in 2 seconds. His average power output is ( g =10m/sec):

• A. 1050 watts✓
• B. 970 watts
• C. 1500 watts
• D. 1300 watts
• E. 500 watts

Explanation: The average power output is calculated using the formula for power, P = Work/Time. In this context, the work done is equivalent to the gravitational potential energy, E = mgh, where m is the mass (70 kg), g is the gravitational acceleration (10 m/s²), and h is the height (3 m). Substituting these values, we get P = (70 * 10 * 3) / 2 = 1050 watts.Options B, C, D, and E do not use the correct substitution in the formula, leading to incorrect power calculations. Ensure each step uses the correct formula and values.

Q77. The torque will be greater if:

• A. Both magnitude of force and moment arm are smaller
• B. Both magnitude of force and moment arm are greater✓
• C. Only magnitude of force is greater
• D. Only moment arm is greater
• E. None of the above

Explanation: The formula for torque is T=Fr. Hence Torque will be greater if the magnitude of the force and moment arm are greater.

Q78. Example(s) of spin motion is/are:

• A. The daily rotation of the earth about its own axis
• B. Jumping of a paratrooper from an helicopter
• C. Flow of a viscous liquid
• D. Rotation of flywheel about its axle
• E. Both the daily rotation of the earth and flywheel about its own axis✓

Explanation: Spin motion is the movement of an object about its own axis, which is depicted by;(i) the daily motion of the earth(ii)flywheel rotation about its own axis.

Q79. The sum of Kinetic Energy and Potential Energy is always constant provided:

• A. There is some force of friction involved during the motion of the body
• B. There is no force of friction involved during the motion of the body✓
• C. There is greater force of friction involved during the motion of the body
• D. Both; there is some force of friction involved during the motion of the body & no force of friction involved during the motion of the body
• E. None of the above

Explanation: The principle of conservation of mechanical energy states that the total mechanical energy in a system remains constant when only conservative forces are acting. Conservative forces, like gravity, do not dissipate energy as heat, whereas non-conservative forces, such as friction, do. Therefore, in the presence of friction, mechanical energy is not conserved as it is converted into other forms, primarily heat. This makes Option B correct, as it specifies the absence of friction. Other options incorrectly assume that energy conservation is possible with friction or provide contradictory or non-applicable scenarios.

Q80. A block with a mass of 0.1 kg is attached to a spring and placed on a horizontal frictionless table. The spring is stretched 20 cm when a force of 5 N is applied, the spring constant is:

• A. 50 Nm-1
• B. 25 Nm-1✓
• C. 75 Nm-1
• D. 100 Nm-1
• E. 125 Nm-1

Explanation: To find the spring constant k, use Hooke's Law: F = kx. Given that F = 5 N and the extension x = 0.2 m, the equation becomes:5 = k(0.2)Solving for k gives k = 5 / 0.2 = 25 Nm-1.Option B is correct because it accurately reflects this calculation.Options A, C, D, and E are incorrect because they do not match the calculated value of the spring constant. They either overestimate or underestimate the spring constant due to incorrect application of the formula.

Q81. If the resultant intensity of the interfering waves is zero or less than the intensity of the individual wave, then this type of interference is:

• A. Destructive interference✓
• B. Constructive interference
• C. Stable interference
• D. Both constructive and destructive interference
• E. None of the above

Explanation: Destructive interference occurs when two interfering waves are 180 degrees out of phase, leading to a cancellation of their amplitudes and a resultant intensity of zero or less than that of the individual waves. Constructive interference, on the other hand, happens when waves are in phase, resulting in a greater overall intensity. The term 'stable interference' is not standard in wave theory, and 'both constructive and destructive interference' does not apply here as the condition described specifically matches destructive interference.

Q82. The smaller the distance of the object from the eye, the visual angle will be:

• A. Smaller
• B. Greater✓
• C. Constant
• D. Negligible
• E. None of the above

Explanation: The visual angle of an object is determined by the size of the object's image on the retina. This angle increases as the object comes closer to the observer because the image projected on the retina becomes larger. Therefore, when the distance of the object from the eye decreases, the visual angle becomes greater. Option B is correct because it accurately describes this relationship. Other options fail to capture this dynamic change in visual angle with distance.

Q83. A system absorbs 2000 Joules of heat and delivers 1200 Joules of work while losing 200 Joule of heat by conduction to the atmosphere. The change in the internal energy of the system is:

• A. 300 J
• B. 600 J✓
• C. 1200 J
• D. 900 J
• E. 1500 J

Explanation: The change in internal energy of a system is determined using the first law of thermodynamics, which states: Change in internal energy (ΔU) = Heat absorbed (q1) - Work done (W) - Heat lost (q2).Given: q1 = 2000 J, W = 1200 J, q2 = 200 J.Thus, ΔU = 2000 J - 1200 J - 200 J = 600 J.This calculation correctly considers all forms of energy transfer, leading to the correct answer of 600 J.Other options are incorrect because they either ignore the heat lost, wrongly calculate the heat absorbed, or do not properly apply the formula.

Q84. The efficiency of the Carnot's Engine working between 150°C and 50°C is:

• A. 22.3%
• B. 20.0%
• C. 23.6%✓
• D. 30.6%
• E. 33.6%

Explanation: The efficiency of a Carnot engine is calculated using the formula η% = (1 - T2/T1) × 100%, where T1 is the temperature of the hot reservoir and T2 is the temperature of the cold reservoir in Kelvin.Convert the given temperatures from Celsius to Kelvin: T1 = 150°C + 273 = 423 K and T2 = 50°C + 273 = 323 K.Substituting these values into the formula, η% = (1 - 323/423) × 100% = 23.6%.Options A, B, D, and E either apply the formula incorrectly or suggest efficiencies that are not supported by the calculated values.

Q85. An electron is situated midway between two parallel plates 0.5 cm apart. One of the plates is maintained at a potential of 60 volts above the other. The force on the electron is: (e = -1.6x10-19C)

• A. 1.82x10-15 N
• B. 3.00x10-16 N
• C. 1.92x10-15 N✓
• D. 3.00x10-15 N
• E. 5.00x10-15 N

Explanation: To solve this problem, we first calculate the electric field (E) between the parallel plates using the formula E = V/d, where V is the potential difference and d is the distance between the plates. Here, V = 60V and d = 0.5 cm = 0.005 m. Thus, E = 60V/0.005m = 12,000 V/m.Next, we apply the formula for the force on a charge in an electric field: F = eE. The charge of an electron is e = -1.6x10-19 C. Therefore, F = (1.6x10-19 C)(12,000 V/m) = 1.92x10-15 N.Option A is incorrect due to a possible miscalculation of E. Option B underestimates the force, likely from an error in applying the formula. Option D overestimates the force, possibly by using incorrect values. Option E significantly overestimates the force, indicating a misunderstanding of the relationship between V, d, and the resulting force.

Q86. The principle of a capacitor is based on which of the following facts?

• A. The potential of a conductor increases when the charge on it decreases, but this affects the charge stored in it.
• B. The potential of a conductor is greatly reduced when the charge on it increases.
• C. The potential of a conductor increases without affecting the charge stored in it.
• D. The potential of a conductor is greatly reduced without affecting the charge stored in it.✓
• E. The potential of a conductor increases as the charge on it increases.

Explanation: The correct answer is that the potential of a conductor is greatly reduced without affecting the charge in it. This is the fundamental principle behind capacitors, which are used to store electric charge by reducing the electric potential of a conductor while maintaining its charge. This is achieved by introducing another conductor, either earth-connected or oppositely charged, in proximity to the first. Other options are incorrect because they either involve increasing potential or affecting the charge, which do not describe how capacitors function.

Q87. A current of 4.4 amperes is flowing in a wire. How many electrons pass a given point in the wire in one second, if the charge on an electron is 1.6x10-19 Coulomb?

• A. 1.5 x 1019 electrons
• B. 2.75 x1019 electrons✓
• C. 3.25 x1019 electrons
• D. 2.75 x 1015 electrons
• E. 3.25 x 1017 electrons

Explanation: 4.4 Amperes means that 4.4 coulomb of charge passes through the conductor in one second.1e contains 1.6x10-19 C , so 4.4 C will contain 4.4/1.6x10-19= 2.75x1019 electrons.

Q88. The translocation of organic solutes in sieve-tube members is supported by:

• A. Cytoplasmic streaming
• B. Root pressure and transpiration pull
• C. P-proteins
• D. Mass flow involving a carrier and ATP✓

Explanation: According to the mass flow hypothesis, the transport of organic solutes takes place from source to sink, this transport also depends on metabolic energy. According to the cytoplasmic streaming hypothesis (which was given by de Vries, in 1885) the transport of organic solutes takes place by a combination of diffusion and cytoplasmic streaming. Cytoplasmic streaming carries organic solutes from one end to the other end of the sieve tube. P-proteins have a role as a defense against phloem-feeding insects and the sealing of damaged sieve tubes. So, the correct answer is 'Mass flow involving a carrier and ATP'. So correct option is C.

Q89. A force which is experienced in a magnetic field depends on:

• A. magnitude of charge q
• B. speed of the moving charge v
• C. magnitude of magnetic field B
• D. all of these✓
• E. none of these

Explanation: The force experienced by a charge moving in a magnetic field is given by the formula F = qvB sin(θ), where q is the charge, v is the velocity of the charge, and B is the magnetic field strength. The angle θ is the angle between the velocity vector and the magnetic field lines. Therefore, the force depends on the magnitude of the charge, the speed of the moving charge, and the strength of the magnetic field. Option D correctly identifies all these factors. Options A, B, and C each identify only one of these factors, which is insufficient on its own. Option E is incorrect as it suggests that the force depends on none of these factors, which is contrary to the established formula.

Q90. A coil of 600 turns is threaded by a flux of 8x10-5 webers if this flux is reduced to 3x10-5 webers in 0.015 seconds. The average induced e.m.f. is:

• A. -2.0 volts
• B. -3.0 volts
• C. +2.0 volts✓
• D. +2.5 volts
• E. +3.0 volts

Explanation: Emf = - N (dФ/dt)where number of turns are denoted by N, dФ is the change in flux and dt is the time interval.Change in flux = Final Flux - Initial FluxChange in flux = (3 × 10⁻⁵) - (8 × 10⁻⁵) WbChange in flux = - (5 × 10⁻⁵) Wbtime interval = 0.015 sectime interval = 15 × 10⁻³ secNumber of turns in coil = 600Putting all the values in formula.Emf = - 600 × (-(5 × 10⁻⁵)/15 × 10⁻³) VoltsEmf = 600 × (5 × 10⁻²/15 ) VoltsEmf = 600 × (10⁻²/3 ) VoltsEmf = 200 × 10⁻² VoltsEmf = 2 Volts

Q91. Which of the following work (s) on the principle of wheatstone Bridge?

• A. Slide-wire bridge
• B. Meter bridge
• C. Post office box
• D. All of these✓
• E. None of these

Explanation: The correct answer is 'All of these'. Each option - slide-wire bridge, meter bridge, and post office box - utilizes the Wheatstone Bridge principle. This principle involves balancing the ratios of resistances to find unknown values, which is a common feature in all these devices. The 'None of these' option is incorrect because it contradicts the shared underlying principle of these devices.

Q92. The sinusoidal wave form can be varied by using which of the following parameters?I. Frequency of the carrier wave II. Amplitude of the carrier wave IIl. Phase angle

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

Explanation: To modulate a sinusoidal wave, you can vary its amplitude, frequency, or phase angle. These parameters affect different characteristics of the wave:Amplitude: Changes the wave's intensity or loudness.Frequency: Alters the pitch or tone of the wave.Phase Angle: Shifts the wave's position in time, introducing phase shifts or time delays.Thus, all three parameters can be used to modulate a sinusoidal wave, making option E the correct choice. Other options are incorrect because they exclude one or more of these critical parameters.

Q93. A semiconductor photodiode is a:

• A. Reverse-biased junction diode✓
• B. Forward-biased junction diode
• C. Half wave rectifier
• D. Full wave rectifier
• E. Transistor

Explanation: A semiconductor photodiode is a reverse-biased junction diode. In reverse bias, the photodiode's depletion region widens, allowing for efficient generation and collection of charge carriers (electron-hole pairs) when exposed to light. This configuration enables the photodiode to operate in the photoconductive mode, providing a fast response to changes in light intensity.The incorrect options do not describe how photodiodes function: Forward bias (Option B) is inappropriate for photodiodes as it limits sensitivity; half wave (Option C) and full wave rectifiers (Option D) are rectification circuits and unrelated to photodetection; and transistors (Option E) serve different functions such as amplification and switching, not light detection.

Q94. The speed of light is very nearly equal to;

• A. 5x108 m/sec
• B. 3x1016 m/sec
• C. 4x108 m/sec
• D. 3x108 m/sec✓
• E. 7x108 m/sec

Explanation: The speed of light in a vacuum is a fundamental constant of physics, known to be approximately 3x108 meters per second. This value is critical for many areas of physics and technology, including the theory of relativity. Option D correctly represents this speed. The other options are either too high or too low, and do not match the universally accepted value.

Q95. Radiation can cause:

• A. leukemia
• B. radiation sickness
• C. skin cancer
• D. gene mutations
• E. all of the above✓

Explanation: Radiation can lead to multiple adverse health effects, including leukemia, radiation sickness, skin cancer, and gene mutations. Each of these outcomes stems from the ability of radiation to damage biological tissues and DNA. Leukemia is linked to radiation's impact on bone marrow, radiation sickness results from acute high-level exposure, skin cancer is associated with UV radiation, and gene mutations can occur due to ionizing radiation disrupting DNA. Therefore, the most comprehensive answer is all of the above, as radiation can indeed cause all these effects.

Q96. The haemoglobin of a human foetus

• A. The hemoglobin of a human fetus has only 2 protein subunits instead of 4
• B. The hemoglobin of a human fetus has a higher affinity for oxygen than that of an adult✓
• C. The hemoglobin of a human fetus has a lower affinity for oxygen than that of an adult
• D. Its affinity for oxygen is the same as that of an adult

Explanation: A. The hemoglobin of a human fetus has only 2 protein subunits instead of 4: This statement is not accurate. Hemoglobin, in both fetuses and adults, consists of four protein subunits. The structure of hemoglobin remains consistent in this regard.B. The hemoglobin of a human fetus has a higher affinity for oxygen than that of an adult:This statement is accurate. Fetal hemoglobin (HbF) has a higher affinity for oxygen than adult hemoglobin (HbA). This higher affinity allows fetal hemoglobin to effectively extract oxygen from the mother's bloodstream, where the oxygen concentration is lower, and deliver it to the developing fetus.C. The hemoglobin of a human fetus has a lower affinity for oxygen than that of an adult:This statement is not accurate. As mentioned earlier, fetal hemoglobin actually has a higher affinity for oxygen compared to adult hemoglobin.D. Its affinity for oxygen is the same as that of an adult:This statement is not accurate. Fetal hemoglobin (HbF) and adult hemoglobin (HbA) have different oxygen affinities, with HbF having a higher affinity for oxygen.Correct Option: B. The hemoglobin of a human fetus has a higher affinity for oxygen than that of an adult.Summary: The correct option is B, which accurately states that fetal hemoglobin (HbF) has a higher affinity for oxygen compared to adult hemoglobin (HbA). This difference in oxygen affinity helps facilitate the efficient transfer of oxygen from the mother's bloodstream to the developing fetus during pregnancy. The other options either present inaccurate information or claim that the affinity for oxygen is the same in fetal and adult hemoglobin.

Q97. A nucleus consists of 11 protons and 12 neutrons. The conventional symbol of nucleus is:

• A. 11Na12
• B. 11Ca23
• C. 11Na23✓
• D. 11Ca12
• E. 11Ca12

Explanation: 11 protons are present in sodium(Na) not in calcium(Ca). The conventional symbol of the nucleus contains proton number(p) and mass number(p + n). So the answer is 11Na23, which is mentioned in option C.

Q98. The dimensions of acceleration are:

• A. LT-1
• B. LT-2✓
• C. L3
• D. L2
• E. LT2

Explanation: To find the dimensions of acceleration, start by understanding that acceleration is the change in velocity over time.Velocity is defined as distance over time, which has dimensions of [L][T-1].Thus, acceleration, being velocity per time, is [L][T-1]/[T] = [L][T-2].Option A ([LT-1]) is the dimension of velocity, not acceleration. Option C ([L3]) corresponds to volume, Option D ([L2]) to area, and Option E ([LT2]) is a miscalculation of time's exponent. Only Option B accurately reflects the dimensions of acceleration: [LT-2].

Q99. All of the following is/are scalar quantities except:

• A. Temperature
• B. Density
• C. Volume
• D. Force✓
• E. Speed

Explanation: Scalar quantities are defined by having only magnitude, such as temperature, density, volume, and speed. These quantities do not involve any direction.Force is the exception here as it is a vector quantity, meaning it has both magnitude and direction, which is why it is not a scalar quantity.While temperature, density, volume, and speed are described without direction, force is characterized by the direction in which it acts as well as its strength.

Q100. R1 and R2 are two-position vectors making angles θ1 and θ2 with positive X-axis respectively. Their vector product is:[R1 = 4 cm, R2 = 3 cm , θ1 = 30 degrees , θ2 = 90 ]

• A. 12√3
• B. 6√3✓
• C. 6√12
• D. 12√6
• E. 3√6

Explanation: The vector product of two vectors, R1 and R2, is given by the formula |R1 × R2| = |R1| |R2| sin(θ2 - θ1), where θ is the angle between the vectors. Here, |R1| = 4 cm, |R2| = 3 cm, θ1 = 30°, and θ2 = 90°. Thus, |R1 × R2| = 4 × 3 × sin(90° - 30°) = 4 × 3 × 1/2√3 = 6√3 cm.This calculation confirms that the correct answer is 6√3 cm, directed along the Z-axis.The incorrect options result from errors in either the trigonometric calculations or angle substitutions, leading to incorrect values.