Uhs Mdcat 2023 — Solved Past Paper with Answers

Q1. Choose the sentence that is grammatically correct:

• A. He weighed himself two pounds.
• B. He weighed two pounds.✓
• C. He weighed themselves two pounds.
• D. He weighed itself two pounds.

Explanation: Option A is correct as it shows correct subject-pronoun agreement.

Q2. Choose the correct option.We felt as if the ground was _ beneath our feet.

• A. Digging
• B. Sinking
• C. Slipping✓
• D. Bursting

Explanation: This is an informal expression that means feeling unstable or losing one’s footing. It’s often used metaphorically to describe a situation where things are unpredictable or uncertain. In the context of the sentence, it conveys the idea that the ground is not stable beneath our feet.

Q3. A few years ago, it _ that human beings do not belong to this earth.

• A. Found
• B. Was found✓
• C. Were found
• D. Had found

Explanation: In the given statement, "A few years ago" represents that the sentence is in past tense, and "it" represents that helping verb should be singular. Option D is incorrect because if we used had, it should should have been followed by "been". Hence, correct option is B.

Q4. A shoal of fish _ killed by the fishermen.

• A. Has been✓
• B. Have
• C. Had
• D. Has

Explanation: Correct, because "shoal" is a singular noun (referring to a group of fish treated as a single entity), so the singular form "has been" is used.

Q5. At last the fly was _. The most appropriate word to be filled in is:

• A. Trapped by the spider✓
• B. Entertained by the spider
• C. Invited by the spider
• D. Spared by the spider.

Explanation: Trapped by the spider is correct, as it suggests the fly was caught or ensnared by the spider, which is a common scenario in nature.

Q6. Choose the correct meaning of the underlined word;Providentially, his mind was not injured.

• A. Slowly
• B. Suddenly
• C. Luckily✓
• D. Unfortunately

Explanation: Some common synonyms of providentially are fortunately, happily, and luckily. While all these words mean "meeting with unforeseen success," providentially more definitely implies the help or intervention of a higher power.

Q7. A carpenter carves _ on cab doors. Choose the right word to fill in the blank.

• A. Arabesque✓
• B. Ornate
• C. Decked
• D. Floral

Explanation: "Arabesque" refers to intricate, decorative patterns often used in woodwork and carvings, making it the most appropriate word for the kind of design a carpenter might carve on cab doors.Decked means decorated or adorned, but it’s a verb/adjective, not a thing you carve. You can deck something, but you can’t carve a decked.Ornate is an adjective meaning heavily decorated. Again, you can’t carve ornate — you can carve ornate patterns.Floral is an adjective meaning flower-related, not a noun. You can carve floral designs, but not just floral.

Q8. Choose the correct option. _ methods don't work.

• A. This
• B. These✓
• C. The
• D. That

Explanation: Correct, because "these" is used to refer to multiple things that are close in context or time, fitting with "methods" (plural).

Q9. We just _ a game of tennis.

• A. Has
• B. Had✓
• C. Have
• D. Have had

Explanation: The correct answer is had because the sentence uses the past perfect tense, indicating that the game of tennis was completed before another past action or event.

Q10. The pen is expensive; still, I _ it.

• A. Bought✓
• B. Will buy
• C. Have bought
• D. Buyed

Explanation: The correct answer is 'bought' because the sentence refers to a completed action in the past. The word 'still' indicates that despite the pen being expensive, the action of buying it has already occurred. 'Will buy' is incorrect as it suggests a future action, which contradicts the implication of 'still.' 'Have bought' is unsuitable because the present perfect tense is not needed here as it implies an ongoing relevance to the present. 'Buyed' is a simple grammatical error, as the correct past tense is 'bought.'

Q11. Punctuate the given sentence correctly.My father is Chairman of the Committee on Internal Relations he also heads the Discipline Committee.

• A. My father is Chairman of the Committee on Internal Relations. He also heads the Discipline Committee.✓
• B. My father is Chairman of the Committee on Internal Relations - he also heads the Discipline Committee.
• C. My father is Chairman of the Committee on Internal Relations: he also heads the Discipline Committee.
• D. My father is Chairman of the Committee on Internal Relations, but he also heads the Discipline Committee.

Explanation: Option A represents correct punctuation for the given sentence since there is a full stop after first independent sentence.

Q12. Which of the following sentences is correct?

• A. I want to live near my parents live
• B. I want to live where my parents live✓
• C. I want to live where, my parents live
• D. I want to live where: my parents live

Explanation: Correct because "where" properly introduces the clause "my parents live," making the sentence grammatically sound.

Q13. Read the following passage to answer the given question:Right after the Civil War, many distraught soldiers made their way West to find fame and fortune. Some could not go home because there were no homes to go to. The war had devastated them. One young man, Will Goodlad, made his fortune in the hills of Colorado. He found gold in a little river near Grand Junction. His fortune was short lived, however. In 1875, he declared bankruptcy and returned to the land of his birth- the Piedmont of South Carolina. For which side did Will fight during the War?

• A. East
• B. West
• C. North
• D. South✓

Explanation: The passage indicates that Will Goodlad was born in the Piedmont of South Carolina, a state that was part of the Confederacy during the Civil War. Therefore, it is likely that he fought for the South. The terms East and West do not correspond to sides in the Civil War, and while it is possible for a Southerner to have fought for the North, the passage suggests loyalty to his birthplace.

Q14. Which part is the most appropriate to be filled in the blank?_ so many people been out of work as today.

• A. More than ever before
• B. Never before have✓
• C. In the past, there never have
• D. Formerly, there never were

Explanation: It forms an appropriate inverted sentence structure for emphasis, meaning that it has never happened to such an extent before.

Q15. Spot the error out of the bracketed words. We try to speak (with) (one another) (but) (convey) _nothing.

• A. With✓
• B. One another
• C. Convey
• D. But

Explanation: The correct answer is with because the phrase 'speak with one another' is not idiomatic in English. The proper expression is 'speak to one another,' which indicates direct communication between people. The other options are correctly used: 'one another' refers to mutual actions, 'convey' is correctly used in its base form, and 'but' effectively contrasts the two clauses.

Q16. In winter, the days and nights is cold. Choose the part of the sentence that carries error:

• A. In winter
• B. The days
• C. And nights
• D. Is cold✓

Explanation: The subject “the days and nights” is plural, but the verb is is singular.To match the plural subject, the verb should be are, not is.So the correct sentence is: “In winter, the days and nights are cold.”This correction ensures proper subject–verb agreement.Therefore, the error lies in part D (is cold).

Q17. Which of the following is the main point of Darwinism?

• A. Snake's legs
• B. Natural selection✓
• C. Muscle atrophy
• D. Movement of ear

Explanation: Natural selection: Correct, as the main point of Darwinism is the theory of natural selection, which explains how traits that are beneficial for survival are passed on to future generations.

Q18. According to evolutionary studies,prokaryotes may have arisen around:

• A. 2.5 billion years ago
• B. 3.5 billion years ago✓
• C. 4.5 billion years ago
• D. 5.5 billion years ago

Explanation: Prokaryotes are believed to take origin around 3.5 billion years ago

Q19. The enzyme which can work on ph 7 of the medium is?

• A. Pepsin
• B. Sucrase
• C. Pancreatic lipase
• D. Chymotrypsin✓

Explanation: Chemotrypsin is the enszyme that works at pH of 7. Indicating that it works at neutral condition

Q20. Which enzyme is different from others?

• A. Pepsin
• B. Trypsin
• C. Chymotrypsin
• D. Lactase✓

Explanation: Option D lactase is the enzyme, which is different from all other enzymes mentioned above

Q21. Competitive inhibitors are _?

• A. Homologous to substrate✓
• B. Analogous to substrate
• C. Smaller than substrate
• D. Larger than substrate

Explanation: Homologous to substrate: Correct, as competitive inhibitors are structurally similar (homologous) to the substrate, meaning they share a similar shape and structure that allows them to bind to the enzyme’s active site, competing with the substrate.

Q22. The active sites of enzymes are composed of?

• A. Few Nucleotides
• B. Few Nucleosides
• C. Few Saccharides
• D. Few Amino Acids✓

Explanation: Enzymes are completely made up of protein, so the active site is also made up of proteins

Q23. NAD is important?

• A. Enzyme
• B. Coenzyme✓
• C. Hormone
• D. Vitamin

Explanation: NAD is a very important co enzyme for different reactions happening in human body

Q24. What is true about oxytocin?

• A. Acts on kidney tubules
• B. Stimulates ICSH
• C. Perform cellular functions
• D. Dilate milk ducts of mammary glands✓

Explanation: Dilate milk ducts of mammary glands: Correct, as oxytocin is responsible for stimulating milk ejection by contracting the muscles around the milk ducts, aiding in lactation.

Q25. In a typical nerve the action potential duration is:

• A. 1 millisecond✓
• B. 1 microsecond
• C. 1 second
• D. 1 minute

Explanation: In a typical nerve, the action potential duration is about 1 ms. In skeletal muscle cells, the action potential duration is approximately 2-5 ms. In contrast, the duration of cardiac action potentials ranges from 200 to 400 ms.

Q26. During resting membrane potential condition:

• A. Outer surface of neuron is more positive✓
• B. Inner surface of neuron is more positive
• C. Both of these surfaces are equally positive
• D. Both of these surfaces are equally negative

Explanation: The outer surface is more positive than the inside due to a greater quantity of +ve ions in the outer environment.

Q27. The value of the active membrane potential of the neuron is:

• A. 0.01 volts
• B. 0 02 Volts
• C. 0.05 Volts✓
• D. 0.07 Volts

Explanation: The action potential of a neuron typically peaks at around 0.05 V (or 50 mV) during the depolarization phase, which is the rapid increase in membrane potential when a neuron fires. This is the most appropriate value for the peak of the action potential.

Q28. The chemical messengers that transmit action potential across the synapse in the form of chemicals are?

• A. Synaptic knob of synapse
• B. Reflex actions
• C. Neurotransmitters✓
• D. Acetylcholinesterase

Explanation: Neurotransmitters: Correct, as neurotransmitters are the chemical messengers that transmit signals across the synapse between neurons.

Q29. The pressure receptors that receive deep pressure stimulus in the human body are called:

• A. Meisener Corpuscles
• B. Pacinian Corpuscles✓
• C. Red Blood Corpuscles
• D. Cholesterol

Explanation: A Pacinian corpuscle is a type of deep-pressure and vibration-sensitive nerve ending in the skin and other tissues that responds to changes in pressure. These large, encapsulated receptors have an onion-like structure and are found in the subcutaneous tissue of the hands and feet, as well as in other locations like joints and internal organs. They are essential for perceiving deep touch and fast vibrations.

Q30. Cells of different types can be distinguished on the basis of surface:

• A. Phospholipids
• B. Globular proteins
• C. Glycolipids and glycoproteins✓
• D. Cholesterol

Explanation: Glycolipids and glycoproteins presence are the basic factors for differentiating cells

Q31. Mitosis, a type of cell division, is observed in ?

• A. E. Coli
• B. Nostoc
• C. Blue green algae
• D. Cyanobacteria
• E. None of these✓

Explanation: Mitosis is the process by which a eukaryotic somatic cell divides to produce two genetically identical daughter cells. It ensures that each daughter gets an exact copy of the parent cell’s linear chromosomes; the DNA is first replicated during S phase of interphase, and then mitosis apportions the duplicated chromosomes so the two new nuclei are genetically identical. Mitosis proceeds through a well-defined sequence of stages — prophase, prometaphase, metaphase, anaphase, and telophase — coordinated with cytokinesis (physical cell splitting). Key features of mitosis include condensation of chromatin into visible chromosomes, formation of the mitotic spindle (microtubule-based apparatus) to move chromosomes, and precise separation of sister chromatids to opposite poles.

Q32. Which of the following types of organs are supposed to be functional in ancestral species rather than in present-day species?

• A. Vestigial organs✓
• B. Homologous organs
• C. Analogous organs
• D. Embryonic organs

Explanation: The type of organs that are supposed to be functional in ancestral species rather than in present-day species are Vestigial organs.Vestigial organs are body parts that have lost their original function over time and are considered remnants of a species' evolutionary history. Examples in humans include the appendix, wisdom teeth, and tailbone, which are believed to have had more significant functions in our ancestors but are now reduced or non-functional. Studying these structures provides evidence for evolution, as they indicate shared ancestry and how a species adapts to its environment.

Q33. The descending aorta is bifurcated into two vessels, which further divide from the femoral artery that supplies blood to the thigh muscles of the legs:

• A. iliac vein
• B. iliac artery✓
• C. temporal artery
• D. Sciatic artery

Explanation: The descending aorta is bifurcated into two vessels called the common iliac arteries (Option B). These common iliac arteries further divide into the external iliac artery and the internal iliac artery. The external iliac artery is the vessel that supplies blood to the muscles of the legs, including the high muscles of the legs.So, the correct answer is:B. Iliac artery

Q34. The final destination of lymph is:

• A. Lymph Nodes
• B. Lymphoid organs
• C. Lymph capillaries
• D. Subclavian vein✓

Explanation: Lymph eventually returns to the bloodstream by entering the subclavian vein, where it mixes with the blood and is recirculated through the body. This is how excess interstitial fluid and waste products are removed from tissues and transported back to the circulatory system for processing and elimination.

Q35. The ABO blood group is controlled by more than two alleles in a population. This shows that ABO blood group is an example of:

• A. Polygenic Inheritance
• B. Multiple Alleles✓
• C. Operons
• D. Allelic interaction

Explanation: In the ABO blood group system, there are more than two alleles (A, B, and O) that control the blood type in a population. Each individual inherits two alleles from their parents, resulting in a combination of these multiple alleles determining their blood type.

Q36. According to Mendel's Law of Segregation, one individual out of four in the F2 generation had a phenotype that failed to express in the generation.

• A. F1✓
• B. F2
• C. F3
• D. P1

Explanation: F1: Correct, as the F1 generation refers to the first filial generation produced by crossing two parents. According to Mendel's Law of Segregation, all F1 offspring will express the dominant phenotype, and the recessive trait is not expressed in this generation. It is only in the F2 generation (the second filial generation) that the recessive phenotype can reappear, but the question is about the F1 generation, where the recessive phenotype is hidden.

Q37. Test cross is made to check the genotype of a trait. Which of the following crosses is a test cross?

• A. Unknown x At
• B. Unknown x tt✓
• C. Unknown x AB
• D. Unknown x TT

Explanation: A test cross is a cross between an individual with an unknown genotype for a particular trait and an individual that is homozygous recessive for that trait. The purpose of the test cross is to determine the genotype of the unknown individual by observing the phenotypic ratios of the offspring. This cross involves a homozygous recessive individual (tt), which is the test cross. The offspring from this cross will reveal the genotype of the unknown individual.

Q38. The term menopause means:

• A. Start of menstruation
• B. Start of ovulation
• C. Stop of ova production✓
• D. Degeneration of ovaries

Explanation: Menopause is the stage in a woman's life when her ovaries stop producing eggs (ova) and she ceases to have menstrual periods, typically occurring in her late 40s or early 50s.

Q39. Production of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland of a female is controlled by:

• A. Ovary
• B. Uterus
• C. Stimulated follicles
• D. Hypothalamus✓

Explanation: The production of Follicle-stimulating hormone (FSH) and Luteinizing Hormone (LH) from the pituitary gland in females is controlled by HypothalamusThe hypothalamus releases gonadotropin-releasing hormone (GnRH), which then stimulates the anterior pituitary gland to produce and release FSH and LH. These hormones play a crucial role in regulating the menstrual cycle and the development and release of eggs from the ovaries.The ovaries(Option A) and stimulated follicles (Option C) are involved in responding to FSH and LH, but the initial control comes from the hypothalamus.The uterus (Option B) does not directly control the production of FSH and LH.

Q40. Cartilage is a type of what tissue?

• A. Connective tissues✓
• B. Epithelial tissues
• C. Muscular tissues
• D. Nervous tissues

Explanation: Cartilage is a type of connective tissue. It is a flexible and semi-rigid tissue found in various parts of the body, including the joints, ears, nose, and respiratory passages. Connective tissues serve various functions in the body, such as providing structural support, connecting and anchoring organs, and cushioning joints.

Q41. Irregular striation and involuntary control is related to:

• A. Smooth muscle cells
• B. Cardiac muscle cells✓
• C. Skeletal muscle cells
• D. Fibroelastic cartilage cells

Explanation: The correct answer is Cardiac muscle cells because they possess irregular striations and operate under involuntary control, managed by the autonomic nervous system. In contrast, Smooth muscle cells lack striations and are involuntarily controlled, but they are associated with smooth, not irregular, muscle tissue. Skeletal muscle cells have regular striations and are under voluntary control, making them unsuitable for the characteristics described. Fibroelastic cartilage cells are not muscle cells and do not exhibit striations, further disqualifying them as an option.

Q42. The cell membrane of a muscle cell is:

• A. Sarcoplasm
• B. Sarcolemma✓
• C. Sarcomere
• D. Myofibrils

Explanation: The sarcolemma is the specialized cell membrane of muscle cells, also known as muscle fibers. It surrounds and encapsulates the muscle cell, playing a crucial role in the excitation-contraction coupling process, which is essential for muscle contraction. Sarcomere (Option C) is the basic structural and functional unit of a muscle fiber, while sarcoplasm (Option A) refers to the cytoplasm of a muscle cell. Myofibrils (Option D) are long, thread-like structures within muscle cells that contain the contractile proteins responsible for muscle contraction.

Q43. During the sliding of actin filaments, ATP is used for?

• A. Cross bridge formation
• B. Cross bridge breaking✓
• C. Dragging filaments
• D. Shortening of filaments

Explanation: ATP is needed for breaking the bridge between the myosin and the actin.

Q44. To study sex linkages in Drosophila, Morgan mated white eyed males with wild type red eyed females. What will be the phenotye of offspring?

• A. All red eyed males and females✓
• B. Red eyed females and white eyed males
• C. White eyed females and red eyed males
• D. All white eyed females and males

Explanation: In Drosophila melanogaster, the gene for eye color is located on the X chromosome, and the white-eyed trait is a recessive mutation. The wild type, or normal, eye color in Drosophila is red, which is the dominant trait. When white-eyed males (homozygous for the recessive trait) are mated with wild type red-eyed females (homozygous for the dominant trait), the offspring will inherit one X chromosome from each parent. Since the white-eyed trait is recessive, the presence of a dominant red-eyed allele on the other chromosome will result in the offspring having red eyes. Therefore, all the offspring, both males and females, will have red eyes.

Q45. Enteron is the characteristic feature of:

• A. Phylum Porifera
• B. Phylum Cnidaria✓
• C. Phylum Platyhelminthes
• D. Phylum Echinodermata

Explanation: In cnidarians, there is only one cavity, which serves as a digestive as well as a body cavity, which is called the gastrovascular cavity or enteron.

Q46. The body of which is called metamerically segmented?

• A. Cnidarians
• B. Nematodes
• C. Annelids✓
• D. Sponges

Explanation: The body of Annelids is called metamerically segmented. Annelids are a group of worms, including earthworms and leeches, that exhibit metamerism, which means their bodies are divided into a series of repeating segments or metameres. Each segment typically contains similar structures and can perform similar functions, such as locomotion using segmental muscles and housing specific internal organs. This segmentation is a characteristic feature of annelids and sets them apart from the other phyla listed.

Q47. Excretion in Planaria takes place by ?

• A. Malpighian tubules
• B. Protonephridia✓
• C. Metanephridia
• D. Nephron

Explanation: Excretion in Planaria takes place through **protonephridia** (Option B). Protonephridia are a network of tubules with ciliated cells that help regulate the osmotic balance and remove metabolic wastes from the body of flatworms like Planaria. They are a primitive excretory system that plays a role in maintaining the internal environment of these organisms. Malpighian tubules (Option A) are found in insects and are involved in excretion in that group. Metanephridia (Option C) are a type of excretory organ found in some segmented worms. Nephrons (Option D) are functional units of the vertebrate kidney and are not found in planaria or other flatworms.

Q48. A four-chambered heart with a right systemic arch only is present in?

• A. Amphibians
• B. Reptiles
• C. Birds✓
• D. Mammals

Explanation: A four-chambered heart with a right systemic arch is present in BirdsBirds have a unique circulatory system in which they possess a four-chambered heart with complete separation of oxygenated (left side) and deoxygenated (right side) blood, but they have a right systemic arch. This adaptation allows them to meet the high oxygen demands of their active lifestyles, such as flying. Mammals (Option D) also have a four-chambered heart, but they typically have a left systemic arch. Amphibians (Option A) and reptiles (Option B) generally have three-chambered hearts with varying degrees of mixing of oxygenated and deoxygenated blood.

Q49. The movement of water to a lower solute concentration area through a semipermeable membrane is?

• A. Osmotic Potential✓
• B. Pressure potential
• C. Soil potential
• D. Solute potential

Explanation: The movement of water to a lower solute concentration area through a semipermeable membrane is called **osmotic potential** (Option A). Osmotic potential represents the tendency of water to move from a region of lower solute concentration (higher water potential) to a region of higher solute concentration (lower water potential) in order to equalize the concentration of solutes on both sides of the membrane.The other terms mentioned are related to water potential in plants:Pressure potential (Option B) refers to the physical pressure exerted on the cell membrane due to the turgor pressure in plant cells.Solute potential (Option D) is a component of water potential that is directly related to the concentration of solutes in a solution.Soil potential (Option C) is not a standard term used in plant physiology, but it may refer to the water potential in soil, which is influenced by factors such as soil moisture and solute concentration.

Q50. The _ describes how water and dissolved chemicals are carried through the cell wall and intercellular gaps of plants.

• A. Apoplast Theory✓
• B. Symplast Theory
• C. Vacuolar Theory
• D. Cytoplasmic Theory

Explanation: The theory that describes how water and dissolved chemicals are carried through the cell wall and intercellular gaps of plants is called the **Apoplast Theory** (Option A).In the Apoplast Theory, water and solutes move through the non-living, porous spaces outside the plasma membrane (cell wall and intercellular spaces) without entering the living protoplasts of the cells. This pathway includes the cell walls, spaces between cells, and the plant's vascular tissue.The Symplast Theory (Option B), on the other hand, describes the movement of water and solutes through the living cytoplasm of the plant cells, where they pass from one cell to another through plasmodesmata.The Vacuolar Theory (Option C) and Cytoplasmic Theory (Option D) are not recognized theories related to the movement of water and dissolved chemicals in plants.

Q51. Feeding by living in or on the other organism (host) belonging to different species is called?

• A. Mineral nutrition
• B. Parasitic nutrition✓
• C. Saprophytic nutrition
• D. Symbiotic nutrition

Explanation: Feeding by living in or on another organism (host) belonging to a different species is called **parasitic nutrition** (Option B). Parasites obtain nutrients from their host organism, often causing harm or damage to the host in the process.

Q52. Which of the following viruses contains single-stranded DNA?

• A. Adenovirus
• B. Herpes virus
• C. Parvovirus✓
• D. Pox virus

Explanation: Parvoviruses are a group of viruses that carry a single-stranded DNA genome. They are among the smallest DNA viruses and typically infect animals, including humans.

Q53. Which one of the following is an X-linked dominant disorder?

• A. Haemophilia
• B. Color blindness
• C. Hypophosphatemic rickets✓
• D. Becker muscular dystrophy

Explanation: Hypophosphatemic rickets is an X-linked dominant disorder. X-linked dominant disorders are genetic conditions caused by mutations in genes located on the X chromosome.

Q54. Only those genes can assort independently whose loci are on:

• A. Same chromatids
• B. Same chromosomes
• C. Non -homologous chromosomes✓
• D. Homologous chromosomes

Explanation: Independent assortment refers to the random assortment of genes located on different chromosomes during meiosis. Genes located on non-homologous chromosomes (chromosomes that do not have corresponding pairs) can assort independently because their segregation and assortment are not influenced by the behavior of genes on other chromosomes. Genes on the same chromosome (Option B) may be linked and do not assort independently, while genes on homologous chromosomes (Option D) may undergo some level of independent assortment but can also be influenced by genetic recombination.

Q55. Smooth muscles are found in all the mentioned below except:

• A. Trachea
• B. Bronchi
• C. Bronchioles
• D. Alveoli✓

Explanation: Bronchi are larger airway passages in the respiratory system, and they are primarily lined with cartilage for structural support. Smooth muscles are found in the trachea (Option A) and bronchioles (Option C), where they play a role in regulating the diameter of the airways and controlling airflow. Alveoli (Option D) are small air sacs in the lungs where gas exchange occurs, and they do not contain smooth muscles.

Q56. The method of bringing oxygenated air into contact with a gas exchange surface is called ?

• A. Photorespiration
• B. Ventilation✓
• C. Gaseous transport
• D. Respiration

Explanation: Ventilation is the process of moving air in and out of the respiratory system, allowing for the exchange of gases (such as oxygen and carbon dioxide) between the respiratory surface (e.g., lungs or gills) and the external environment. It is a fundamental process for organisms with respiratory systems to obtain oxygen for respiration and remove carbon dioxide as a waste product.

Q57. The number of layers of cell wall in Gram-positive bacteria is:

• A. 1✓
• B. 2
• C. 3
• D. 4

Explanation: In Gram-positive bacteria, there is only one major layer in the cell wall, while Gram-negative bacteria have two major layers in the cell wall.

Q58. Helicobacter pylori is an example of:

• A. Cocci
• B. Bacilli
• C. Pleomorphic✓
• D. Spiral

Explanation: Helicobacter pylori exists as both a helix-shaped form (classified as a curved rod) and a coccoid form. Hence, it is classified as a pleomorphic bacterium.

Q59. Bacterial cell have ability to maintain its shape through :

• A. Cell wall✓
• B. Capsule
• C. Cell wall & slime
• D. Slime

Explanation: The bacterial cell wall is a rigid structure that provides structural support and helps maintain the shape of the bacterial cell. It is responsible for giving bacteria their characteristic shapes, such as rod-shaped (bacilli), spherical (cocci), or spiral (spirilla), and it also plays a role in protecting the cell from osmotic pressure changes.The capsule (option B) and slime (option D) are not primarily responsible for maintaining the cell shape but may have other functions, such as protecting the cell or aiding in adhesion. Option C mentions both the cell wall and slime, but the cell wall is the primary component responsible for shape maintenance.

Q60. Which of the following is an example of spiral-shaped bacteria?

• A. Diplococcus pneumoniae
• B. Hyphomicrobium✓
• C. Escherichia coil
• D. Pseudomonas

Explanation: Hyphomicrobium is a genus of bacteria that exhibits a spiral or helical shape. It is known for its spiral or curved rod morphology. The other options, Diplococcus pneumoniae (Option A), Escherichia coli (Option C), and Pseudomonas (Option D), do not typically exhibit a spiral shape; they have different bacterial morphologies.

Q61. All the following are disinfectants to control bacterial growth except:

• A. Tincture of Iodine✓
• B. Potassium Permanganate
• C. Mercuric Chloride
• D. Hydrogen Peroxide

Explanation: **Tincture of iodine** (option A) is not typically used as a disinfectant to control bacterial growth. Tincture of iodine is more commonly used as an antiseptic for disinfecting skin or mucous membranes. It contains iodine dissolved in alcohol and is often used for wound care or as a preoperative skin disinfectant.The other options, **Mercuric Chloride** (Option C), **Potassium Permanganate** (Option B), and **Hydrogen Peroxide** (Option D), can be used as disinfectants to control bacterial growth in various settings. They are more commonly employed for this purpose.

Q62. The function of hyaluronidase enzyme is:

• A. Penetration of the sperm into the Ovum✓
• B. Entrance of the sperm into the vagina tube
• C. Entrance of the sperm into the fallopian
• D. Inactivation of sperms after their failure to fertilize ovum

Explanation: The process of fusion of a sperm with the ovum is called fertilization. Before fusion of a spermatozoan with the egg, the spermatozoan has to penetrate a few barriers, the egg membranes, which cover the egg. The secretions of the acrosome help the sperm to enter into the cytoplasm of the ovum through the zona pellucida and the plasma membrane. All the chemicals are contained in the acrosome located at the tip of the sperm head and are collectively called sperm lysins. [e.g., CPE, Zonalysin, Hyaluronidase]. The function of hyaluronidase is to puncture the vitelline membrane of an egg.

Q63. In human females, what is the small, pear-shaped, muscular, distensible, sac-like organ where gestation takes place?

• A. Uterus✓
• B. Kidney
• C. Fallopian tube
• D. Stomach

Explanation: In human females, the small, pear-shaped, muscular, distensible, sac-like organ where gestation takes place is UterusThe uterus is where fertilized eggs implant and develop into embryos and fetuses during pregnancy. It plays a crucial role in supporting the growth and development of the developing fetus until birth. The fallopian tubes (Option C) are where fertilization typically occurs, but gestation does not take place in the fallopian tubes. Kidneys (Option B) and the stomach (Option D) are not directly involved in gestation and pregnancy.

Q64. A virus is what type of agent?

• A. Cellular agent
• B. Infectious agent✓
• C. Non-infectious agent
• D. Non-protein agent

Explanation: Viruses are regarded as infectious agents because they enter and take over host cells, leading to various diseases. Their ability to replicate only inside living cells is what makes them capable of causing infections.

Q65. The molecules used to control viruses during infection of animal cells are:

• A. Interferons✓
• B. Histone
• C. Antigen
• D. Serum

Explanation: Interferons are proteins that play a key role in controlling viral infections. They boost the body’s immune defenses and help limit the spread of viruses within the body. The other options listed (antigen, histone, and serum) are not molecules specifically used to control viruses during infection but may have other roles in immune responses or cellular processes.

Q66. The provirus of HIV is structurally and chemically made up of?

• A. ssRNA
• B. ssDNA
• C. dsRNA
• D. dsDNA✓

Explanation: The provirus of HIV (Human Immunodeficiency Virus) is structurally and chemically made up of dsDNA (double-stranded DNA)HIV, a retrovirus, initially enters host cells as single-stranded RNA (ssRNA) but undergoes reverse transcription to convert its RNA genome into double-stranded DNA (dsDNA). This dsDNA is integrated into the host cell's genome as the provirus, and it serves as a template for the production of new viral particles. So, the provirus contains dsDNA.

Q67. Which of the following is used in baking?

• A. Aerobic respiration
• B. External respiration
• C. Internal respiration
• D. Anaerobic respiration✓

Explanation: During the process of baking, anaerobic respiration is used by yeast to convert sugars in dough into carbon dioxide gas, which causes the dough to rise. So, option D is selected.

Q68. Which is the major event in the electron transport chain?

• A. ATP synthesis✓
• B. Substitution
• C. Decarboxylation
• D. Isomerization

Explanation: The electron transport chain is responsible for the production of ATP through a process called oxidative phosphorylation. As electrons are passed along the chain, a proton gradient is established, and the energy released during this process is used to drive the synthesis of ATP from ADP and inorganic phosphate. This ATP synthesis is the primary purpose of the electron transport chain in cellular respiration. The other options listed (decarboxylation, isomerization, and substitution) are not the major events in the electron transport chain.

Q69. Out of 36 ATPs, how many are produced in the electron transport chain?

• A. 28
• B. 30
• C. 32✓
• D. 34

Explanation: Out of the 36 ATPs that can potentially be generated through oxidative phosphorylation and the electron transport chain, approximately **32** ATPs are produced. The precise number can vary depending on specific factors and conditions, but 32 ATPs is a commonly cited estimate for the net ATP yield in eukaryotic cells during cellular respiration.

Q70. The major enzyme involved in the transfer of the phosphate group from ATP to glucose is:

• A. Isomerase
• B. Dehydrogenase
• C. Kinase✓
• D. Decarboxylase

Explanation: The major enzymes involved in the transfer of a phosphate group from ATP to glucose are kinases (Option C). Specifically, the enzyme hexokinase is responsible for catalyzing this phosphorylation reaction, where a phosphate group is transferred from ATP to glucose to form glucose-6-phosphate.The other enzymes listed (isomerase, dehydrogenase, and decarboxylase) are involved in different types of biochemical reactions and are not responsible for this specific phosphorylation step in glucose metabolism.

Q71. _ forms almost three-fourth of the body by weight.

• A. Water✓
• B. Protein
• C. Carbohydrates
• D. Lipids

Explanation: Water (Option A) forms almost three-fourths of the body by weight. The human body is composed of a significant amount of water, which plays a crucial role in various physiological processes and is a major component of cells and tissues. Carbohydrates (Option C), proteins (Option B), and lipids (Option D) make up a smaller proportion of the body by weight compared to water.

Q72. Energy is ------- by the breakdown of complex molecules into simpler ones; such reactions are called catabolic reactions:

• A. Released✓
• B. Consumed
• C. Produced
• D. Destroyed

Explanation: Energy is released by the breakdown of complex molecules into simpler ones, and such reactions are called catabolic reactions. Catabolic reactions involve the breakdown of larger molecules into smaller ones, and this process releases energy that can be used by the cell or organism for various metabolic activities.

Q73. Biologically, it plays key roles in maintaining the integrity of lipid bilayer membranes.

• A. Hydrophilic exclusion
• B. Hydrophobic✓
• C. Specific heat capacity exclusion
• D. Heat of vaporization

Explanation: Biologically, the hydrophobic interactions (Option B) play key roles in maintaining the integrity of lipid bilayer membranes. Lipid bilayers, such as the cell membrane, consist of hydrophilic (water-attracting) head groups and hydrophobic (water-repelling) tails. The hydrophobic interactions between the hydrophobic tails of lipid molecules help to stabilize the bilayer structure and keep the hydrophilic head groups facing the aqueous environment, which is essential for the proper functioning of cell membranes.

Q74. The specific heat of vaporization of water plays an important role in the regulation of heat produced by:

• A. Reduction
• B. Oxidation✓
• C. Redox
• D. None of above

Explanation: The specific heat of vaporization of water plays an important role in the regulation of heat produced by OxidationSpecific heat of vaporization refers to the amount of heat energy required to change a substance from a liquid to a gas without changing its temperature. In the case of water, a significant amount of heat energy is needed to convert liquid water into water vapor (gas) due to the hydrogen bonds between water molecules. This property of water helps regulate and stabilize temperatures in biological systems and prevents rapid temperature changes during chemical reactions, including oxidation processes, which involve the release of heat energy.

Q75. Which type of bond must be broken for water to vaporize?

• A. Nonpolar covalent bonds
• B. Polar covalent bonds
• C. Hydrogen bonds✓
• D. Covalent bonds

Explanation: For water to vaporize (turn from a liquid into a gas), the type of bond that must be broken is Hydrogen bondsWater molecules are held together by hydrogen bonds, which are relatively weak interactions compared to the covalent bonds holding the hydrogen and oxygen atoms within each water molecule (covalent bonds are not broken during vaporization). When water vaporizes, the hydrogen bonds between water molecules are disrupted, allowing the molecules to escape into the gas phase. This requires energy input to break the hydrogen bonds and convert liquid water into water vapor.

Q76. Which statement is true regarding both starch and cellulose?

• A. They are both polymers of glucose✓
• B. They are geometric isomers of each other
• C. They can both be digested by humans
• D. They are both used for energy storage in plants

Explanation: The statement that is true regarding both starch and cellulose is that they are both polymers of glucose.Both starch and cellulose are composed of glucose monomers linked together, but the type of linkage and the arrangement of glucose units differ. Starch consists of glucose molecules linked by α-1,4-glycosidic bonds and sometimes α-1,6-glycosidic bonds, making it a storage polysaccharide in plants. Cellulose, on the other hand, consists of glucose molecules linked by β-1,4-glycosidic bonds, forming a structural polysaccharide in plant cell walls.The other statements are not true:C. They cannot both be digested by humans. Humans can digest starch but not cellulose because we lack the necessary enzymes to break the β-1,4-glycosidic bonds in cellulose.B. They are not geometric isomers of each other. Geometric isomers are a type of stereoisomer with a different spatial arrangement of atoms around a double bond. Starch and cellulose are not isomers of each other.D. While starch is used for energy storage in plants, cellulose is primarily used for structural support in plant cell walls, not for energy storage.

Q77. Most of the monosaccharides form a ring structure when in solution. For example, ribose will create a five cornered ring known as:

• A. Glucopyranose
• B. Ribofuranose✓
• C. Glyceraldehyde
• D. Acetaldehyde

Explanation: When most monosaccharides are in a solution, they tend to form ring structures. Ribose, for example, forms a five-membered ring, which is known as RibofuranoseThe five-membered ring structure of ribose is called ribofuranose. In contrast, a six-membered ring is referred to as glucopyranose (Option A). Glyceraldehyde (Option C) and acetaldehyde (Option D) are not related to the ring structures of ribose or other common monosaccharides.

Q78. Cyclosis and amoeboid movements are due to:

• A. Microtubule
• B. Cilia
• C. Microfilaments✓
• D. Intermediate filaments

Explanation: Cyclosis (the streaming movement of cytoplasm within a cell) and amoeboid movements (the crawling-like movements of certain cells, such as amoebas and white blood cells) are primarily due to MicrofilamentsMicrofilaments, which are composed of actin protein subunits, are responsible for the contractile and movement-related activities within the cell. They play a key role in cellular processes involving changes in shape, cell motility, and the movement of organelles or materials within the cell. Cilia (Option B) are hair-like structures found on the cell surface and are primarily involved in cell locomotion and moving substances over the cell's surface. Microtubules (Option A) are involved in various cellular processes, including cell division and providing structural support. Intermediate filaments (Option D) provide structural support and are less involved in cellular movements compared to microfilaments.

Q79. Proteins and lipids are modified into glycoproteins and glycolipids by which cell organelle?

• A. Golgi complex✓
• B. Rough Endoplasmic Reticulum
• C. Smooth Endoplasmic Reticulum
• D. Ribosomes & chromosomes

Explanation: Proteins and lipids are modified into glycoproteins and glycolipids primarily by the Golgi complex (also known as the Golgi apparatus or Golgi body).The Golgi complex is involved in post-translational modification of proteins and lipids, including the addition of carbohydrate chains to proteins (glycoproteins) and lipids (glycolipids), which are important for various cellular functions, including cell-cell recognition and signaling. Rough endoplasmic reticulum (Option B) is involved in protein synthesis and initial protein folding, while smooth endoplasmic reticulum (Option C) plays a role in lipid metabolism and detoxification. Ribosomes and chromosomes (Option D) are not directly involved in the modification of proteins and lipids into glycoproteins and glycolipids.

Q80. Which structure of the prokaryotic cell will play the role of the mitochondrion?

• A. Spores
• B. Cyst
• C. Nucleoid
• D. Mesosomes✓

Explanation: In prokaryotic cells, which lack membrane-bound organelles like mitochondria, the role of generating energy through cellular respiration is carried out by the cell membrane and infoldings of the cell membrane called mesosomes.Mesosomes in prokaryotic cells play a role in cellular respiration and energy production, similar to the function of mitochondria in eukaryotic cells. The other options, spores (Option A), cysts (Option B), and nucleotides (Option C), do not directly perform the role of mitochondria in energy production.

Q81. The cell wall of a prokaryotic cell is composed of:

• A. Carbohydrates✓
• B. Carbohydrates and Proteins
• C. Proteins
• D. Proteins & Lipids

Explanation: The correct answer is Carbohydrates, as prokaryotic cell walls are predominantly composed of peptidoglycan, which is a polymer made from carbohydrates (sugars) linked to amino acids. While they may contain other molecules, the fundamental structure relies on carbohydrates.Options B, C, and D incorrectly emphasize proteins or lipids as primary components of the prokaryotic cell wall, which is not accurate. Prokaryotic cells differ significantly from eukaryotic cells, which may have cell walls made of cellulose (in plants) or chitin (in fungi), but the prokaryotic cell wall's unique composition is critical to its function and structural integrity.In Official UHS 2023 paper, option A was marked as correct. Therefore, we will retain option A here to maintain alignment with the original key for authenticity.

Q82. Which of the following transition metals show a 3d5 configuration in their +2 oxidation state?

• A. Cu+2
• B. Fe+2
• C. Mn+2✓
• D. Zn+2

Explanation: Mn²⁺: Manganese in the +2 oxidation state has an electron configuration of [Ar] 3d⁵, which is a half-filled d-subshell, making it stable.

Q83. Which of the following reagents can be used to distinguish between 1-pentyne and 2-pentyne?

• A. AgNO3 + NH4OH✓
• B. 1% alkaline dilute KMnO4
• C. Br2/CCI4
• D. K2Cr2O7 +H2SO4

Explanation: AgNO3 + NH4OH and K2Cr2O7 + H2SO4 are the reagents that can effectively distinguish between 1-pentyne and 2-pentyne.

Q84. In SN1 reactions, the correct order of reactivity of alkyl halide is?

• A. Primary>secondary>tertiary
• B. Tertiary>secondary>primary✓
• C. Secondary>primary>tertiary
• D. Primary>tertiary >secondary

Explanation: Tertiary > Secondary > Primary (Correct)Explanation: Tertiary carbocations are the most stable due to inductive and hyperconjugation effects, making tertiary alkyl halides the most reactive in SN1 reactions.

Q85. What is the IUPAC name of diisopropyl ketone?

• A. 1,3-Diisopropylpropan-2-on
• B. 2,4-Dimethylpentan-3-one✓
• C. 2,4-Dimethylpentan-2-one
• D. 1,3-Dimethylpropan-2-one

Explanation: 2,4-Dimethylpentan-3-oneExplanation:Diisopropyl ketone refers to a ketone with two isopropyl groups attached to the carbonyl carbon.The correct structure has two methyl groups at positions 2 and 4 on a pentane chain, with the carbonyl group at position 3, hence the name 2,4-dimethylpentan-3-one.

Q86. The appearance of a silver mirror in Toliens test indicates the presence of which of the following?

• A. A ketone
• B. An aldehyde✓
• C. An acid
• D. An alcohol

Explanation: Aldehyde (Correct)Explanation: Aldehydes reduce Tollens' reagent (Ag⁺) to metallic silver, creating a silver mirror on the test tube.

Q87. Competitive inhibitors stop an enzyme from working by:

• A. Changing the shape of the enzyme
• B. Merging with the substrate instead
• C. Blocking the active site of the enzyme✓
• D. Combining with the product of the reaction

Explanation: Blocking the active site of the enzyme: Correct answer—Competitive inhibitors block the active site by binding to it, preventing the substrate from binding.

Q88. If phenol is treated with 3 moles of conc. HNO₃ in the presence of H₂SO₄, what will be the product?

• A. o-nitrophenol
• B. p-nitrophenol
• C. o-nitrophenol and p-nitrophenol
• D. picric acid✓

Explanation: Picric acid: Correct answer—When phenol is treated with concentrated nitric acid in the presence of sulfuric acid, it undergoes nitration, leading to the formation of picric acid (2,4,6-trinitrophenol), which is the major product.

Q89. When the 6d orbital is filled, the entering electron goes into?

• A. 7f
• B. 7d
• C. 7p✓
• D. 7s

Explanation: According to the Aufbau principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p. Hence, option C is correct.

Q90. Which element has the ground state electronic configuration of 1s2, 2s2, 2p6, 3s2 ,3p6?

• A. Ar✓
• B. Cl
• C. Na
• D. S

Explanation: The ground state electronic configuration given as 1s², 2s², 2p6, 3s², 3p6, corresponds to the electronic configuration of the element Argon.

Q91. What is the proton (atomic number) of an element that has four unpaired electrons in its ground state?

• A. 6
• B. 14
• C. 22
• D. 26✓

Explanation: The number of unpaired electrons in an element's ground state corresponds to the element's atomic number, which is the number of protons in its nucleus. In this case, an element with four unpaired electrons would have an atomic number of 26. Iron has an atomic number of 26; it has four unpaired electrons in its ground state electronic configuration:1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d⁶

Q92. Which one of the following gases has the lowest density under room conditions?

• A. Neon✓
• B. Nitrogen
• C. Oxygen
• D. Fluorine

Explanation: Molar Mass: Approximately 20.18 g/mol.Density: Neon is a noble gas with a low molar mass, resulting in a low density compared to the other options. At room temperature and pressure, its density is around 0.9002 g/L, making it the least dense of the four gases listed.

Q93. The process of heat flow between hotter and colder gases remains continued until all the molecules have equal:

• A. Average translational kinetic energy✓
• B. Average rotational kinetic energy
• C. Average translational potential energy
• D. Average vibrational kinetic energy

Explanation: Heat flow between hotter and colder gases continues until all the molecules have an equal average translational kinetic energy due to the principle of thermal equilibrium. In this state, there is no net transfer of heat between the gases, as they reach the same temperature. The process continues until thermal equilibrium is achieved, ensuring that energy is distributed uniformly among the molecules, resulting in a balanced and stable system.

Q94. What is the ultimate fate of a reversible reaction?

• A. Completion of reaction
• B. Complete consumption of reactants
• C. Complete consumption of products
• D. A state when there is no net concentration change✓

Explanation: A state when there is no net concentration change: Correct answer—The ultimate fate of a reversible reaction is a dynamic equilibrium where the concentrations of reactants and products remain constant over time, with no net change.

Q95. In a reversible reaction, when a product is removed, the equilibrium shifts towards the:

• A. Reactant side
• B. Product side✓
• C. Both side, one by one
• D. No effect

Explanation: Product side: Correct answer—When the product is removed in a reversible reaction, the equilibrium shifts toward the product side to produce more product, according to Le Chatelier's principle.

Q96. The rate of reaction between two specific time intervals is called?

• A. Instantaneous rate of reaction
• B. Average rate of reaction✓
• C. Rate of reaction
• D. Minimum rate of reaction

Explanation: The average rate of reaction is calculated by taking the ratio of the change in concentration of reactants or products over a specific time interval. It represents the overall rate of reaction during that time interval. The average rate of reaction is often calculated using the initial and final concentrations of reactants or products.

Q97. How will be the rate of reaction if the slope of the curve is greater near the start of the reaction?

• A. Constant
• B. Equilibrium
• C. Greater✓
• D. Lesser

Explanation: The correct option is C, greater. If the slope of the curve is greater near the start of the reaction, it indicates a rapid initial reaction rate.

Q98. What is the reason for energy changes in chemical reactions?

• A. Bond formation
• B. Bond breakage
• C. Bond formation and breakage✓
• D. Ionic bonds

Explanation: A. Bond formation: This option is correct because energy changes in chemical reactions often occur when new chemical bonds are formed. When new bonds are created, energy may be released, resulting in an exothermic reaction.

Q99. What is the unit of heat capacity?

• A. JK-1✓
• B. kJmol-1
• C. k/K
• D. kJ.mol

Explanation: Heat capacity is defined as the amount of heat energy required to raise the temperature of a body by 1 Kelvin (or 1°C).Since heat energy is measured in Joules (J) and temperature change in Kelvin (K), the unit of heat capacity becomes Joule per Kelvin (J K⁻¹).It expresses how much energy an object can absorb before its temperature increases.A higher heat capacity means the substance can absorb more heat without a large rise in temperature.For example, water has a high heat capacity, which helps regulate temperature in living organisms and the environment.This concept is fundamental in thermodynamics and physical chemistry.Therefore, the SI unit of heat capacity is J K⁻¹.

Q100. The addition reaction of 2-butene with HBr produces?

• A. 1-bromobutane
• B. 2-bromobutane✓
• C. 2,3-dibromobutane
• D. 1,3-dibromobutane

Explanation: The addition of HBr to 2-butene forms 2-bromobutane. Since it's a symmetrical alkene, it does not follow Markonivkov rules.

Q101. Under suitable conditions alkanes cannot undergo _ reactions?

• A. Substitution
• B. Combustion
• C. Hydrogenation
• D. Addition✓

Explanation: The correct option is D. Addition. Under suitable conditions, alkanes do not readily undergo addition reactions. These reactions are more characteristic of alkenes and alkynes.

Q102. A compound of phosphorus oxide has 43.6% of oxygen. Its empirical formula is?

• A. P2O5
• B. P2O3✓
• C. P5O2
• D. PO2

Explanation: Let the total mass of the compound be 100g.Given that the percentage of oxygen is 43.6%. So, the mass of oxygen would also be 43.6g.Now, Mass of phosphorus = 100 - 43.6 = 56.4gNow, calculate the number of moles by dividing with molar masses. P : O 56.4/31 : 43.6/16 1.8 : 2.7 (Divide with smaller number to get a whole number.) 1.8/1.8 : 2.7/1.8 1.5 1(2): 1.5(2) (Divide with a suitable number to get a whole number)3Hence, the phosphorus oxide would be P₂O₃..

Q103. Which element is used as a standard to determine the atomic mass of an element?

• A. H
• B. C✓
• C. P
• D. Cl

Explanation: The correct element used as the standard to determine the atomic mass of other elements is B. C. (carbon).

Q104. The average weight of atoms of an element compared to the weight of one atom of _ is called atomic weight.

• A. Carbon✓
• B. Helium
• C. Hydrogen
• D. Nitrogen

Explanation: The correct element used as the reference to determine atomic weights is A. Carbon.

Q105. The same moles of H2, N2, and O2 are present in 0.1 cc volume at STP. Which one has the greatest number of molecules:

• A. N2
• B. H2
• C. O2
• D. Number of molecules are equal✓

Explanation: The number of molecules is given by the formula:Number of molceules = moles x avogadros constantSince all of the given elements have the same number of moles all of them will have the same number of molecules, which will be 6.02 x 1023, the Avogadros constant.

Q106. Which is not a property of liquid?

• A. Osmotic pressure
• B. Freezing point
• C. Diffusion
• D. Melting✓

Explanation: The correct option is D, melting. Melting is not a property of liquids but a process that occurs when a solid is heated to become a liquid.

Q107. Which type of forces exist between iodine molecules?

• A. Dipole-dipole forces
• B. Dipole-induced dipole forces
• C. Instantaneous dipole-induced dipole forces✓
• D. Non-polar forces

Explanation: The correct type of forces that exist between iodine molecules (I₂) is C. Instantaneous dipole-induced dipole forces (London dispersion forces). Iodine molecules are nonpolar and therefore primarily interact through London dispersion forces.

Q108. In anisotropic crystals, which property does not change with the change in direction of crystalline structure?

• A. Electrical conductance
• B. Thermal conductance
• C. Molar mass✓
• D. Refractive index

Explanation: The property that does not change with the change in the direction of crystalline structure in anisotropic crystals is C, molar mass. Molar mass is an intrinsic property of a substance and remains constant for that substance, regardless of its crystalline orientation.

Q109. In metals, why does electric conductivity decrease with the increase of temperature?

• A. Because electron movement decrease with the increase of temperature
• B. Because metal ions oscillations hinder electron movement✓
• C. Because electron direction changes at high temperature
• D. Because they pass heat current through collision of electrons

Explanation: The correct option is B because metal ion oscillations hinder electron movement. As temperature increases, the vibrational motion of metal ions disrupts the movement of electrons, reducing electrical conductivity in metals.

Q110. Why does fluorine have less electron affinity as compared to bromine?

• A. Electronegativity
• B. Thick, small electronic cloud✓
• C. Seven electrons in outermost shell
• D. Higher ionization energy

Explanation: Fluorine has less electron affinity compared to bromine primarily due to its small atomic size and the associated compact 2p subshell, which leads to greater electron-electron repulsion when an extra electron is added. Additionally, the high electronegativity of fluorine reflects its tendency to hold onto its electrons tightly, which can also affect its affinity for extra electrons. In contrast, bromine's larger size reduces the repulsion experienced when an additional electron is added, resulting in a more favorable electron affinity.

Q111. Which oxyacid of halogen is a strong oxidizing agent?

• A. HClO₄
• B. HClO₃
• C. HClO✓
• D. HClO₂

Explanation: The lower the oxidation state of halogen in an oxyacid, the stronger the oxidizing ability, because it can accept electrons to reach a higher oxidation state.HClO: Cl⁺¹ → strong oxidizerHClO₄: Cl⁺⁷ → already fully oxidized → weak/no oxidizer

Q112. Alkylbenzene is formed when benzene is treated with an alkyl halide In the presence of anhydrous aluminum chloride, Identify the type of reaction.

• A. Halogenation
• B. Friedel-Crafts acylation reaction
• C. Friedel-Crafts alkylation reaction✓
• D. Sulphonation

Explanation: The type of reaction where benzene is treated with an alkyl halide in the presence of anhydrous ammonium chloride to form an alkylbenzene, is known as Friedal-Crafts alkylation reaction.

Q113. The increasing stability order of the following compounds (1 )CH3 CH2 CH2+(2) (CH₃)₃C+(3) CH3 CH2 CH+ CH3 are ?

• A. 1 > 2 > 3
• B. 3 > 2 > 1
• C. 2> 3 > 1✓
• D. 3 > 1 > 2

Explanation: 1. CH₃CH₂CH₂⁺ (Primary carbocation):This is a primary carbocation, meaning it has one alkyl group attached directly to the positively charged carbon atom. Primary carbocations are the least stable among the three options because they lack electron-donating alkyl groups to help stabilize the positive charge.2. (CH₃)₃C⁺ (Tertiary carbocation):This is a tertiary carbocation, meaning it has three alkyl groups attached to the positively charged carbon atom. Tertiary carbocations are the most stable among the three options because they benefit from the electron-donating nature of the three alkyl groups, which helps stabilize the positive charge.3. CH3CH2CH+CH3 (Secondary carbocation):This is a secondary carbocation, meaning it has two alkyl groups attached to the positively charged carbon atom. Secondary carbocations are intermediate in stability between primary and tertiary carbocations.

Q114. When 2-bromopropane reacts with sodium ethoxide, the major product is/are?

• A. Propane
• B. Propene✓
• C. Ethyl isopropyl ether
• D. All are formed

Explanation: The correct major product when 2-bromopropane reacts with sodium ethoxide is B. Propene (propylene).

Q115. Propanone can be prepared from propyne by:

• A. Passing a mixture of propyne and steam over a catalyst, magnesium at 420°C
• B. Passing a mixture of propyne and ethanol over a catalyst, zinc chromate
• C. Boiling propyne with water in the presence of HgSO₄ and H₂SO₄✓
• D. Treating propyne with iodine and NaOH

Explanation: The correct option is C; the explanation is already given.

Q116. If carboxylic acid and ketone groups C=O are present in a chain, then final name will be given as:

• A. oxo, oic acid✓
• B. one, oic acid
• C. Both 1 and 2
• D. None of these

Explanation: The naming convention for compounds containing both a carboxylic acid group and a ketone group involves using the prefix "oxo" to indicate the presence of the ketone group, followed by the name of the alkyl chain attached to the carboxylic acid group, and ending with the suffix "oic acid" to denote the carboxylic acid group.

Q117. Acetic acid is a weaker acid than sulphuric acid because of which of the following reasons?

• A. It decomposes on increasing temperature
• B. It has less degree of ionization✓
• C. It has -COOH group
• D. It has more inductive effect

Explanation: Acetic acid is weaker than sulfuric acid because it has a lesser degree of ionization. Acetic acid partially dissociates into hydrogen ions (H+) and acetate ions (CH3COO-), whereas sulfuric acid is a strong acid that completely dissociates into hydrogen ions (H+) and sulfate ions (SO42-). The degree of ionization refers to the extent to which an acid dissociates into ions in a solution.

Q118. Mr. Khan mixes acetic acid with thionyl chloride. Which product is obtained?

• A. CH₃COCI + SO₂ + HCl✓
• B. CH3CI + CH3COCI
• C. CH3COOCH3 + SO2
• D. CH₃CI + SO₂ + HCI

Explanation: The correct product obtained when acetic acid reacts with thionyl chloride is A. CH3COCI + SO2 + HCl, which forms acetyl chloride along with the release of sulfur dioxide (SO2) and hydrogen chloride (HCl).

Q119. After the digestion & before absorption, the product of the protein is:

• A. Amino Acid and small polypeptide
• B. Only Amino Acid✓
• C. Only small polypeptide
• D. Only ammonia

Explanation: This option suggests that the only product of protein digestion before absorption is amino acids. This is correct option

Q120. Dehydration of alcohol gives which of the following products in the presence of H₂SO₄ at 1400?

• A. Acetaldehyde
• B. Diethyl ether✓
• C. Acetone
• D. Ethyl chloride

Explanation: When alcohols are dehydrated in the presence of conc. H₂SO₄ at a lower temperature, i.e., 140°C, they produce ether.

Q121. Complete oxidation of alcohol gives which of the following?

• A. Aldehyde
• B. Alkane
• C. Carboxylic acid✓
• D. Ketone

Explanation: The correct product of complete oxidation of an alcohol is C. Carboxylic acid.

Q122. One can estimate the direction in which equilibrium will shift with the help of:

• A. Le Chatelier's principle✓
• B. Law of mass action
• C. Hess's law
• D. Law of heat of formation

Explanation: Le Chatelier's principle is a concept that helps in predicting the direction in which a system at equilibrium will shift in response to a change in conditions.

Q123. The bond energy of hydrogen in the H₂ molecule is:

• A. 242 KJ/mol
• B. 431 KJ/mol
• C. 436 KJ/mol✓
• D. 346 KJ/mol

Explanation: So, the correct bond energy of hydrogen in an H2 molecule is C. 436 KJ/mol.

Q124. What are vinyl alcohol and acetaldehyde?

• A. Position isomers
• B. Functional group isomers
• C. Metameres
• D. Tautomers✓

Explanation: The correct description for the relationship between vinyl alcohol and acetaldehyde is D. Tautomers. They are tautomeric forms of each other, which means they can rapidly interconvert.

Q125. What is the oxidation number of free magnesium?

• A. 0✓
• B. +1
• C. +2
• D. +3

Explanation: The correct oxidation number for free magnesium (in its elemental form) is not 0. In its elemental form, magnesium typically has an oxidation number of +2.

Q126. Select the metal that is extracted from bauxite.

• A. Al✓
• B. Ca
• C. Mg
• D. Cu

Explanation: The metal that is extracted from bauxite is A. Al (aluminum).

Q127. Which of the following has the highest atomic radius in its period?

• A. Alkaline earth metals
• B. Alkali metals✓
• C. Chalcogens
• D. Halogens

Explanation: The correct answer is indeed B, alkali metals. Among the options provided, the alkali metals, specifically cesium (Cs), have the highest atomic radius in their respective periods. Cesium has the largest atomic radius among all the alkali metals.

Q128. The electronic configurations of some elements are given below. Recognize the element that belongs to group IIIA

• A. 1s2 2s2 2p3
• B. 1s2 2s2 2p4
• C. 1s2 2s2 2p1✓
• D. 1s2 2s2 2p2

Explanation: The element that belongs to group IIIA (Group 13) of the periodic table is boron (B), so the correct option is C: 1s2 2s2 2p1.

Q129. All alkali metals react with chlorine gas to form white metal chloride salt. The metal chloride salt formed is:

• A. Insoluble
• B. Soluble in water to give neutral solution of ph 7✓
• C. Soluble in water to give acidic solution of ph 1
• D. Soluble in water to give alkaline solution of ph 14

Explanation: The correct description for the metal chlorides formed when alkali metals react with chlorine gas is B. Soluble in water to give a neutral solution of pH 7.

Q130. Which one of them is amphoteric in nature?

• A. Lithium oxide
• B. Beryllium oxide✓
• C. Calcium oxide
• D. Potassium oxide

Explanation: The amphoteric nature is exhibited by B, beryllium oxide (BeO).

Q131. Which of the following is correct electronic configuration of iron (II) ion (atomic no. of Fe is =26)?

• A. [Ar] 4s0, 3d6✓
• B. [Ar] 4s2, 3d6
• C. [Ar] 4s2, 3d4
• D. [Ar] 4s2, 3d5

Explanation: The correct electronic configuration of iron (II) ion (Fe2+) is [Ar] 4s0, 3d6. This configuration indicates that there are 0 electrons in the 4s orbital and 6 electrons in the 3d orbital.

Q132. Which of the functional groups are present in ethyl acetate?

• A. Aldehyde group
• B. Carboxyl group
• C. Ester group✓
• D. Ether group

Explanation: The ester group is present in ethyl acetate. Ester groups consist of a carbonyl group (C=O) bonded to an oxygen atom, which is further bonded to an alkyl or aryl group. In ethyl acetate, the ester group consists of the carbonyl group bonded to an oxygen atom, which is further bonded to an ethyl group.

Q133. What is the molecular formula of the pyridine molecule?

• A. C₆H₅N
• B. C5H5N✓
• C. C5H5NH
• D. C₆H₆N

Explanation: The correct answer is B. The molecular formula C5H5N represents pyridine. Pyridine is a six-membered aromatic ring containing one nitrogen atom and five carbon atoms.

Q134. Identify which method is used to prepare alkynes?

• A. Dehalogenation of Vicinal Dihalides in the Presence of Methanol.
• B. Dehydration of alcohols in the presence of Al₂O₃ at 340-450 degrees centigrade.
• C. Dehalogenation of Vicinal Dihalides in the Presence of Strong Base.✓
• D. Electrolysis of unsaturated dicarboxylic acid salts.

Explanation: A strong base (like alcoholic KOH or NaNH₂) can remove two equivalents of HX from a vicinal dihalide to yield an alkyne. Hence, option C is correct.

Q135. The following formula can be used to determine the resistance of a length of conductor. R pl/A In the formula, the symbol p stands for the:

• A. Cross-sectional area of the conductor in m2
• B. Product of the length of the conductor in meters
• C. Resistivity of the material in units of ohm meters✓
• D. Resistance of the conductor in units of ohms per meter

Explanation: The symbol "p" in the formula represents the resistivity of the material in units of ohm meters.

Q136. The resistance of the wire varies inversely as:

• A. Area of cross section✓
• B. length
• C. Resistivity
• D. Temperature

Explanation: The resistance of a wire does inversely with the area of cross-sectional ,according to the formula: R = ρ * (L/A), where R is resistance, ρ is resistivity, L is length, and A is the cross-sectional area.Correct answer is A.

Q137. A capacitor of capacitance C has charge Q and stored energy is W. lf the charge is increase to 2Q. The stored energy will be:

• A. W/4
• B. W/2
• C. 2W
• D. 4W✓

Explanation: The energy stored in a capacitor is given by the equation: W = Q2 / 2C When the charge Q is increased to 2Q, the new energy W' is: W' = (2Q)2 / 2C = 4Q2 / 2C = 4W Thus, the stored energy becomes four times the original energy, making Option D (4W) the correct choice. The other options misrepresent the relationship between charge and stored energy, as they do not account for the square relationship.

Q138. To store the electric charge the ultra-capacitors use _ effect.

• A. Single layer
• B. Double layer✓
• C. Triple layer
• D. Quadruple layer

Explanation: To store electric charge, ultra-capacitors use the double-layer effect.

Q139. What is the potential difference between two points in an electric field if it takes 600 J of energy to move a charge of 2 C between these two points?

• A. 1200 J
• B. 800 J
• C. 300 J✓
• D. 0 J

Explanation: To find the potential difference (V) between two points in an electric field, you can use the formula: v=W/Q Where: V is the potential difference. W is the work done (energy). Q is the charge. In this case: W = 600 J (work done) Q = 2 C (charge) Now, let's calculate the potential difference (V): V=600J/2C V=300J

Q140. A charged particle moves in a uniform electric field between two oppositely charged parallel metal plates to calculate the force acting on the particle due to the electric field, which quantity is not required?

• A. Particle charge
• B. Particle speed✓
• C. Plate separation
• D. Potential difference between the plates

Explanation: For the calculation of force, velocity of charge is not required since according to the formula V=ED, the V is the potential difference of parallel plates that they receive from source and the magnitude of charge is also important to be mentioned since the force is acting on it.similarly if we put the formula in the equation aboveE=F/QWe get, V=F/q×DWhere D is the distance between plates.Rearranging the formula we get,F/Vq/DIn this way we can calculate the force on a charge due to the electric field between two oppositely charged parallel plates and no velocity is required to calculate force.

Q141. Gauss law cannot be used to find which of the following quantity?

• A. Electric field intensity
• B. Electric flux density
• C. Charge
• D. permittivity✓

Explanation: Gauss's law cannot be used to find permittivity (εo). The value of the permittivity of free space is a fundamental constant in electromagnetism, and it is not determined through Gauss's law.

Q142. Electric field intensity inside a hollow charged sphere is:

• A. Maximum
• B. Zero✓
• C. Negative
• D. Positive

Explanation: The correct electric field intensity inside a hollow charged sphere is B. Zero. The electric field intensity inside a hollow charged sphere is zero. This is because the charges on the inner surface of the hollow sphere create an electric field that cancels out the electric field from the charges on the outer surface, resulting in no net electric field inside the sphere.

Q143. As per Coulomb's law, the force of attraction or repulsion between two-point charges is directly proportional to the:

• A. Sum of the magnitude of charges
• B. Square of the distance between them
• C. Product of the magnitude of charges✓
• D. Cube of the distance

Explanation: Option C is correct. Coulomb's law states that the force is directly proportional to the product of the magnitude of charges (q1 * q2).

Q144. For an ideal gas equation PV= nRT, the dimensions of Real Gas Constant R are:

• A. [M1 L2 T-2 K-1]✓
• B. [M1 L-3 T-1 K-1]
• C. [M1 L-2 T-1 K-1]
• D. [M1 L-3 T-2 K-1]

Explanation: The ideal gas equation is:PV=nRTWhere:P is pressure with dimensions [ML−1T−2]V is volume with dimensions [L³][n is the number of moles (dimensionless),R is the gas constant (which we are solving for),T is temperature with dimensions [K]We rearrange the ideal gas equation to solve for R:R=PV/nTR​Now, substituting the dimensions:P has dimensions of [ML⁻¹T⁻²]V has dimensions of [L³]T has dimensions of [K].So the dimensions of r are:RR=[ML−1T−2]⋅[L³] /K]=[M L2T−2K−1] Thus, the correct answer is [M1 L2 T-2 K-1], which corresponds to Option A.

Q145. A distant star is receding from the Earth with a speed of 1.4o x 107 m/s. It emits light of frequency 4.57 x 1014 Hz. The speed of light is 3.0 x 108 m/s. The Doppler effect formula can be used with light waves. What will bethe frequency of this light when detected on Earth?

• A. 2.04 x 1013 Hz
• B. 4.36 x 1014 Hz✓
• C. 4.57 X 1014 Hz
• D. 4.79 X 1014 Hz

Explanation: Given: v (receding speed) = 1.40 x 10^7 m/s f_source (emitted frequency) = 4.57 x 10^14 Hz c (speed of light) = 3.0 x 10^8 m/s Doppler effect formula for light: f_observed = f_source * sqrt((1 - v/c) / (1 + v/c)) Calculations: v/c = (1.40 x 10^7 m/s) / (3.0 x 10^8 m/s) = 0.0466666... sqrt((1 - v/c) / (1 + v/c)) = sqrt((1 - 0.0466666...) / (1 + 0.0466666...)) sqrt((1 - v/c) / (1 + v/c)) = sqrt(0.9533333 / 1.0466666) sqrt((1 - v/c) / (1 + v/c)) = sqrt(0.9108108) sqrt((1 - v/c) / (1 + v/c)) = 0.9543641 (approximately) f_observed = 4.57 x 10^14 Hz * 0.9543641 f_observed = 4.361936 x 10^14 Hz Result: f_observed = 4.36 x 10^14 Hz (approximately)

Q146. The speed of sound in an ideal gas depends upon:

• A. Ice
• B. Frequency and fog
• C. Temperature and density✓
• D. Density and amplitude

Explanation: The correct statement is C. Temperature and density.The speed of sound in an ideal gas depends on both temperature and density. In fact, the speed of sound is given by the equation:Speed of Sound (v) = √(γ * (Pressure / Density)where γ is the adiabatic index or ratio of specific heats, which depends on the gas, and both temperature and density are involved in this equation.

Q147. If transverse waves are passing through a medium, then particles of the medium:

• A. Remain stationary
• B. Move away
• C. Move toward
• D. Move in Simple Harmonic Motion✓

Explanation: The correct statement is D. Move in Simple Harmonic Motion.The correct description is that particles of the medium move in simple harmonic motion (SHM) when transverse waves pass through. In SHM, particles oscillate back and forth about their equilibrium positions.

Q148. When a wave goes from one medium to another, there is a no change in the:

• A. Frequency✓
• B. Amplitude
• C. Wavelength
• D. Velocity

Explanation: Option A is correct. Frequency is the number of waves that pass a point in one second. When a wave goes from one medium to another, the frequency remains the same. This is a fundamental property of waves known as the principle of frequency invariance.

Q149. Wave trough refers to the:

• A. Wave length
• B. Wave speed
• C. Highest point of the wave
• D. Lowest point of the wave✓

Explanation: The correct statement is D. Lowest point of the wave. The trough is the lowest point in a wave where the displacement of the medium is at its minimum.

Q150. First law of thermodynamics concerns with the conservation of:

• A. Heat
• B. Work
• C. Momentum
• D. Energy✓

Explanation: The correct statement is D. Energy. The first law of thermodynamics concerns the conservation of energy, stating that the total energy of an isolated system remains constant, and energy can be transferred between various forms but cannot be created or destroyed.

Q151. An ideal gas has molar specific heat Cp at constant pressure. When the temperature of n moles is increased by AT the increase in the internal energy is:

• A. nCp △T
• B. n(Cp + R) △T
• C. n(Cp - R) △T✓
• D. n(2Cp + R) △T

Explanation: This is the correct option. It represents the increase in internal energy of an ideal gas when the temperature is increased by ΔT\Delta TΔT. In this equation, nnn is the number of moles, CpC_pCp​ is the molar specific heat at constant pressure, and RRR is the ideal gas constant. The term (Cp−R)(C_p - R)(Cp​−R) reflects the relationship between the specific heats at constant pressure and constant volume. This option shows how internal energy is dependent on the change in temperature and the difference between the specific heats.

Q152. The ohmmeter of a portable digital multi meter need:

• A. Internal battery✓
• B. Wet cell
• C. Voltmeter
• D. Ammeter

Explanation: The correct statement is A. Internal battery. A portable digital multimeter's ohmmeter function usually requires an internal battery to operate.

Q153. A wire of uniform area of cross-section A', length 'L', and resistance R is cut into two equal parts. What will happen to the resistivity of each part?

• A. It will be doubled
• B. It will be one fourth
• C. It will be halved
• D. It will remain the same✓

Explanation: The correct statement is D. It will remain the same. The resistivity of each part of the wire will remain the same after cutting. Resistivity is an intrinsic property of the material and is not dependent on the length or shape of the wire.

Q154. If 0.5 T field is applied over an area of 2-meter square which lies at an angle of 60 degree with the field, then the resulting flux will be:

• A. 0.5 T
• B. 0.5 Wb✓
• C. 0.25 Wb
• D. 0.25 T

Explanation: The correct statement is B. 0.5 Wb. To calculate the magnetic flux, you need to use the formula: Magnetic Flux (Φ) = Magnetic Field Strength (B) × Area (A) × cos(θ) Given: Magnetic Field Strength (B) = 0.5 T Area (A) = 2 m² Angle (θ) = 60 degrees Φ = 0.5 T × 2 m² × cos(60°) Φ = 0.5 T × 2 m² × 0.5 Φ = 0.5 Wb So, the resulting magnetic flux is indeed 0.5 Weber (Wb).

Q155. The magnitude of magnetic force will be maximum on current carrying conductor in uniforrn magnetic field if conductor is placed?

• A. Parallel to magnetic field
• B. At 45 degree in magnetic field
• C. Perpendicular to magnetic field✓
• D. Antiparallel in magnetic field

Explanation: The correct statement is C. Perpendicular to the magnetic field. To achieve the maximum magnetic force on a current-carrying conductor in a uniform magnetic field, the conductor should be placed perpendicular to the magnetic field lines.

Q156. In principle, the transformer consists of two coils of copper, electrically insulated from each other, wound on the same?

• A. Iron core✓
• B. Copper core
• C. Gold core
• D. Steel core

Explanation: The correct statement is A. Iron core. In principle, transformers consist of two coils of copper wire wound on the same iron core. The iron core enhances the magnetic coupling between the coils, allowing for efficient energy transfer in the transformer.

Q157. In Compton effect, the incident photon when compared to the scattered photon is of:

• A. Greater energy
• B. Greater frequency
• C. Greater energy and momentum✓
• D. Equal energy

Explanation: The correct statement is C. Greater energy and momentum. In the Compton effect, the incident photon has greater energy and momentum compared to the scattered photon, as energy and momentum are conserved during the scattering process.

Q158. Which of the following is the longest wavelength of radiation for the Paschen series?

• A. 187000000 m
• B. 187000000/ m
• C. 0.00000187 m✓
• D. 0.00000187 / m

Explanation: Given the options provided, 0.00000187 m (which is 1.87 µm) represents the longest wavelength of radiation in the Paschen series. The other option, 187000000 m, is an exceedingly large wavelength that is not applicable to the Paschen series or any other typical electromagnetic radiation observed in atomic transitions.

Q159. Which of the following is the correct definition of variable velocity?

• A. Unequal distances are covered in equal intervals of time
• B. Equal displacements are made in unequal intervals of time
• C. Unequal displacements are made in equal intervals of time✓
• D. Equal displacements are made in equal intervals of time

Explanation: When an object covers unequal displacements (changes in position) in equal intervals of time is known as variable velocity. This means that the object's speed or rate of change in position varies over time. It can be due to factors such as acceleration or deceleration, where the object is either speeding up or slowing down during the specified intervals of time.

Q160. Which of the following is the fractional change in resistance per kelvin?

• A. Conductivity
• B. Resistivity
• C. Temperature coefficient of resistivity
• D. Temperature coefficient of resistance✓

Explanation: The temperature coefficient of resistance represents how the resistance of a conductor changes with temperature. It is defined as the fractional change in resistance per Kelvin.

Q161. Accoreling to maximum power transfer theorem, which of the following is the max power delivered by the battery to the output?

• A. E2/4r✓
• B. E2/2r
• C. E2/5r
• D. E2/3r

Explanation: The Maximum Power Transfer Theorem in electrical circuits states that to transfer the maximum amount of power from a source (like a battery) to a load (like a resistor), the resistance of the load should be equal to the internal resistance of the source. Here, "E" represents the electromotive force (EMF) of the battery, and "r" represents the internal resistance of the battery. The correct statement is B. E^2/4r. According to the Maximum Power Transfer Theorem, the maximum power is delivered to the load when the load resistance is equal to the internal resistance of the source (battery).

Q162. Velocity selector will select only those charge particles whose velocity is given by:

• A. V= E/B✓
• B. V=B/E
• C. V=ExB
• D. V=0

Explanation: The correct statement is A. V = E/B. In a velocity selector, charged particles with a specific velocity are selected. This velocity is determined by the ratio of the electric field (E) to magnetic field (B) in the selector.

Q163. The induced emf produced in the coil is sometimes called as?

• A. Self-inductance
• B. Back emf✓
• C. Motional emf
• D. Mutual inductance

Explanation: The correct statement is B. Back emf. Back emf is often used to describe the induced emf in a coil or motor, especially in the context of motors and generators.

Q164. Voltage has the same units as that of?

• A. Current
• B. Magnetic induction
• C. Emf✓
• D. Mutual inductance

Explanation: The correct statement is C. Emf. The quantity "Aepitit" has the same units as emf, which is volts (V).

Q165. Working principal of magnetic levitation train is according to?

• A. Faraday law
• B. Max planks law
• C. Ohm law
• D. Lenz law✓

Explanation: Lenz's law is applicable to the operation of magnetic levitation trains. Lenz's law states that an induced current opposes the change in magnetic field that produces it. In the case of magnetic levitation trains, Lenz's law helps maintain the stability and control of the levitation system by opposing any changes in the magnetic field caused by the motion of the train.

Q166. The expression for the emf produced by A. C. generator is?

• A. NωAB Sinθ✓
• B. NωAB Cosθ
• C. NωAB
• D. ILB Cosθ

Explanation: The correct statement is A. NωAB Sinθ. This expression represents the emf produced by an AC generator when the coil is rotated in a magnetic field with an angle θ between the field and the coil's plane.

Q167. For the positive half cycle i.e., 0 -> T/2, the diode D:

• A. Is reverse biased
• B. Is forward biased✓
• C. Behaves as open
• D. Shows maximum resistance

Explanation: The correct statement is B. Is forward biased. During the positive half cycle of an AC input in a rectifier circuit, the diode should be forward biased to allow current to flow and rectify the AC signal.

Q168. The process of ejection of loosely bound electrons from a certain photo sensitive surface by absorption of photon is called:

• A. Compton effect
• B. Photoelectric effect✓
• C. Pair production
• D. Black body radiation

Explanation: The photoelectric effect refers to the phenomenon where photons are absorbed by a photo-sensitive surface, resulting in the ejection of loosely bound electrons from the surface.

Q169. In Compton effect, a photon of a certain wavelength collides with a stationary electron. The wavelength of the emitted photon is:

• A. Longer✓
• B. Shorter
• C. Same
• D. Infinite

Explanation: In Compton effect, the wavelength of the scattered photon is higher than that of the incident photon.

Q170. The Balmer series of hydrogen is important because it:

• A. Is the only one for which the quantum theory be used
• B. Is the only series that occurs for hydrogen
• C. Is in the visible region✓
• D. Involves the lowest possible quantum number "n"

Explanation: Balmar series is the only series that lies in visible region.

Q171. The SI unit of equivalent dose is:

• A. Gray
• B. Mass
• C. Rad
• D. Sievert✓

Explanation: The correct statement is D. Sievert (Sv). The sievert is the SI unit of equivalent dose.

Q172. The decay rate of radioactive substance is:

• A. Constant with time
• B. Varies inversely with time
• C. Decreases exponentially with time✓
• D. Decreases linearly with time

Explanation: The correct statement is C. Decreases exponentially with time. The decay rate of a radioactive substance decreases exponentially as the radioactive nuclei decay over time.

Q173. The relation between gray and rad is given as: 1 Gy = _ rad

• A. 0.01
• B. 0.001
• C. 10
• D. 100✓

Explanation: The correct statement is D. 0.001. The relation between gray and rad is 1 Gy = 100 rad.

Q174. The velocity-time plot for a moving particle shows a straight line. This means:

• A. The particle has a constant acceleration✓
• B. The particle has never turned around
• C. The particle has zero displacement
• D. The data in insufficient

Explanation: The correct statement is A. The particle has a constant acceleration. A straight line on a velocity-time plot typically indicates that the particle is undergoing constant acceleration.

Q175. A man is in a car that is moving with the velocity of 36km/hr.His speed with respect to the car:

• A. 10m/s
• B. 36m/s
• C. Zero✓
• D. Infinite

Explanation: A man is in a car that is moving with a velocity of 36 km/hr. We want to determine the man's speed with respect to the car. The correct statement is C. Zero. The man's speed with respect to the car is zero, meaning he is not moving relative to the car. This is the standard interpretation of speed relative to an object.

Q176. On which car there is resultant force?

• A. Car moving on a straight horizontal road
• B. Car moving at constant speed around a bend✓
• C. Car moving uphill at a constant velocity
• D. Car that is stationary

Explanation: The correct statement is B. Car moving at constant speed around a bend. In this scenario, there is a resultant force (centripetal force) directed towards the center of the bend, which allows the car to maintain a curved path.

Q177. If two equal masses are in motion with same individual speeds, we can conclude that:

• A. Their momentums are same
• B. Their momentums can be different from each other✓
• C. Their kinetic energies are different from each other
• D. Their total energies are same

Explanation: This is the accurate statement. As explained above, momentum is a vector. Even if the masses and speeds are identical, the directions of motion can vary. This variation in direction leads to different momentum vectors. For example, one mass could be moving east, and the other north. In this case, their momentums are not the same.

Q178. The work done by a variable force can be found by dividing the:

• A. Force into small intervals
• B. The displacement into small intervals✓
• C. Both force and displacement into small intervals
• D. By taking displacements at different angles

Explanation: The work done by a variable force is calculated by integrating the force over the displacement. This means that to find the total work, you consider the force acting over small intervals of displacement, as the force may change throughout that distance. The correct answer is Option B, The displacement into small intervals, as it emphasizes the need to account for the variable nature of the force in relation to the distance moved.Option A is incorrect because it neglects the displacement aspect, focusing solely on force. Option C is misleading because it implies a simple multiplication of both factors without addressing the integration needed for variable forces. Option D is incorrect as it does not relate to the calculation of work, which is not determined by angles but by the relationship between force and displacementIn Official UHS 2023 paper, option B was makred as correct. Therefore, we will retain option B here to maintain alingment with the original key for authethicity.

Q179. Two bodies with kinetic energies having a ratio of 4:1, are moving with equal linear momentum. The ratio of their masses is:

• A. 1:2
• B. 1:4✓
• C. 4:1
• D. 1:1

Explanation: Since K.E is inversely propotional to the mass the ratio of the masses will be inverted and would become 1:4.

Q180. A fisherman lifts a fish of mass 250 g from rest through a vertical height of 1.8 m. The fish gains a speed of 1.1 m/s. What is the energy gained by the fish?

• A. 0.15 J
• B. 4.3 J
• C. 4.4 J
• D. 4.6 J✓

Explanation: Potential Energy Gain:The fish gains potential energy due to its change in height. Potential energy (PE) = mgh, where: m = mass (in kg) g = acceleration due to gravity (approximately 9.8 m/s²) h = height (in m) Convert the mass to kilograms: 250 g = 0.25 kg Calculate the potential energy gain:PE = (0.25 kg) * (9.8 m/s²) * (1.8 m) PE = 4.41 J2. Kinetic Energy Gain:The fish also gains kinetic energy due to its speed.Kinetic energy (KE) = 1/2 mv², where: m = mass (in kg) v = speed (in m/s) Calculate the kinetic energy gain:KE = 1/2 * (0.25 kg) * (1.1 m/s)²KE = 1/2 * 0.25 * 1.21KE = 0.15125 J3. Total Energy Gain:The total energy gained is the sum of the potential and kinetic energy gains.Total Energy = PE + KETotal Energy = 4.41 J + 0.15125 JTotal Energy ≈ 4.56 J

Q181. One radian is analogous to:

• A. 57o3'
• B. 57o3"
• C. 57o18'✓
• D. 57o18"

Explanation: 1 radian = 180/π degrees ≈ 57°18′ It’s the angle subtended at the center of a circle by an arc equal in length to the radius.

Q182. In the displacement-time graph, if the slope is constant then the velocity is

• A. Variable
• B. Constant✓
• C. May be variable or constant
• D. Infinite

Explanation: The correct answer is B. When the slope of a displacement-time graph is constant, the velocity of the object is also constant.

Q183. An 8.0-kg box slides along a horizontal frictionless floor at 3 m/s and collides with a relatively massless spring that compresses 12 cm before the box comes to a rest. Calculate the retarding force of the spring.

• A. 3N
• B. 30N
• C. 300N✓
• D. 3000N

Explanation: m=8 kg, v=3 m/s, x=0.12 mFrictionless surfaceWe are asked for the retarding force of the spring.The spring force is not constant (it’s F=kx), but the average force can be calculated from work done:Work done by spring=Kinetic energy of box Favg⋅x=1/2mv2Favg⋅0.12=1/2⋅8⋅32Favg⋅0.12=36 ⟹ Favg=36/0.12=300 N

Q184. The circular line has a fix distance from _?

• A. Any point
• B. A fix point✓
• C. A point on a circle
• D. A point from outside

Explanation: The correct option is B. "A fixed point."A circular line, by definition, is a curve that is equidistant from a fixed point called the center of the circle. The distance from any point on the circular line to the fixed center point remains constant, which is a fundamental property of a circle.

Q185. If a particle is moving with uniform circular motion, then:

• A. Velocity and acceleration are antiparallel
• B. Velocity and acceleration are parallel
• C. Velocity and acceleration are perpendiculars✓
• D. Zero acceleration

Explanation: The correct option is C, "Velocity and acceleration are perpendicular." This option is correct. In uniform circular motion, the velocity and acceleration vectors are always perpendicular to each other. The velocity is tangential to the circular path, while the acceleration (centripetal acceleration) points toward the center of the circle.

Q186. 0ne degree is equal to:

• A. n/90 radians.
• B. n/180 radians.✓
• C. n/270 radians.
• D. n/360 radians.

Explanation: B option is correct. One degree is equal to π/180 radians. This is the standard conversion factor between degrees and radians.

Q187. An observer standing near the sea shore observes 54 waves per minute. If the wavelength of the water wave is 10m then the velocity of water wave is:

• A. 540 m/s
• B. 9 m/s✓
• C. 5.4 m/s
• D. None

Explanation: Frequency (f) = 54 waves per minute.Wavelength (λ) = 10 meters.The velocity (v) of a wave is given by the formula:v = f * λSubstitute the values:v = (54 waves/minute) * (10 meters/wave)First, convert the frequency from waves per minute to waves per second:1 minute = 60 secondsf = 54 waves/minute = (54 waves/minute) * (1 minute/60 seconds) = 0.9 waves/secondNow, calculate the velocity:v = (0.9 waves/second) * (10 meters/wave) = 9 meters/secondSo, the velocity of the water wave is 9 m/s.The correct option is B: 9 m/s.

Q188. If the length of second pendulum becomes four times, then its time period will become:

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

Explanation: By understanding the relationship between the length of a pendulum and its time period, we can deduce that if the length becomes four times, the time period will become two times. This is because the time period is proportional to the square root of the length.

Q189. The labour pains to expel fetus are due to action of oxytocin on:

• A. Endometrium
• B. Myometrium✓
• C. Perimetrium
• D. Ovaries

Explanation: The labor pains to expel the fetus are due to the action of oxytocin on Myometrium Oxytocin is a hormone that is released by the pituitary gland during labor. It acts on the smooth muscle layer of the uterus, known as the myometrium, causing it to contract. These uterine contractions are responsible for pushing the fetus down the birth canal during childbirth. Oxytocin also plays a role in stimulating milk ejection during breastfeeding.

Q190. All children are silly people. Some silly people are rich people. All rich people are big shots. Which of the following conclusions are NECESSARILY TRUE?CONCLUSIONS:I. Some silly people are children.II. Some rich people are children.III. Some silly people are big shots.

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

Explanation: Let's analyze each conclusion one by one: I. "Some silly people are children." This conclusion is necessarily true based on the given statements. While it's mentioned that "All children are silly people," it implies that there are some silly people who are children. It's possible that there are other silly people who are not children. II. "Some rich people are children." This conclusion is not necessarily true based on the given statements. Although it's mentioned that "Some silly people are rich people" and "All children are silly people," it doesn't necessarily mean that there are rich people who are children. There could be rich people who are not children. III. "Some silly people are big shots." This conclusion is necessarily true based on the given statements. It's stated that "Some silly people are rich people" and "All rich people are big shots." Therefore, it's logically consistent that there must be some silly people who are big shots. So, the correct conclusion is: A. I and III I and III are necessarily true based on the given statements, while II is not necessarily true.

Q191. Read the following and choose the correct answer X, Y and Z are three whole numbers less than 31 but greater than 23. X is a prime number. Y is the largest odd number smaller than 35. Z is the smallest even number?

• A. X is 31, Y is 29 and Z is 24
• B. X is 29, Y is 29 and Z is 24✓
• C. X is 23, Y is 29 and Z is 24
• D. X is 27, Y is 31 and Z is 26

Explanation: According to the given question21 is not a prime number so, option A is incorrect.Z is 24 which is not a smallest even number this eliminating option C.As 27 which is not a prime number and z is 26 which is not a smallest even number this rules out option D as well.So the correct option is B.

Q192. Observe the pattern and select the next term in the sequence: SSSSS, SSRSS, SRQRS, RQPQR

• A. RQDQR
• B. QRORQ
• C. RQPOPQR
• D. QPOPQ✓

Explanation: Let's analyze the given sequence:SSSSSSSRSSSRQRSRQPQRIt appears that each term is formed by taking the previous term and replacing one letter with the next letter in the alphabet. Starting with 'S', we have 'S' -> 'R' -> 'Q', and so on.So, to find the next term in the sequence, we'll continue this pattern:RQPQRQPOPQThe correct option is:D. QPOPQ

Q193. Read the following statement, assuming everything in it to be true. Then decide which of the given suggested courses of action logically follow and are worth pursuing.Statement: Your toddler drops and breaks a glass by genuine accident.Courses of Action:I. yell at them to be more careful with things made out of glass.II. Punish them to make sure they remember to be extra careful next time.

• A. I
• B. II
• C. Both I and II
• D. Neither I nor II✓

Explanation: In this situation, it's important to consider the well-being of your toddler and promote a safe learning environment. Let's evaluate the courses of action: I. Yell at them to be more careful with things made out of glass. This course of action involves raising your voice at the toddler. While it may express your frustration, it's not a constructive way to handle the situation, especially if the child's action was a genuine accident. It may lead to fear and anxiety in the child. II. Punish them to make sure they remember to be extra careful next time. - Punishing a toddler for a genuine accident is generally not recommended. It can create fear and stress, and it's not an effective way to teach them about accidents and safety. It's important to remember that toddlers are still learning and exploring their environment. Given the context of the situation, the better course of action is to: D. Neither I nor II

Q194. Read the following statements and identify the best cause and effect relation.I. State P started providing multiple rehabilitation schemes, like free education, job search help and help groups for addicts, etc. over the past year.II. Crimes rates for state P have steadily decreased over the past year.

• A. II is the cause and I is its effect
• B. I is the cause and II is its effect✓
• C. I and II are effects of some common cause
• D. I and II are both effects of independent causes

Explanation: The best cause and effect relation in this scenario is: I is the cause and II is its effect. The implementation of rehabilitation schemes like free education, job search help, and help groups for addicts is likely aimed at reducing crime rates, making it a plausible direct cause of the observed decrease in crime rates in state P.Option A is incorrect because it suggests the opposite causal direction, which is illogical. Option C is less likely because the direct relationship between rehabilitation efforts and crime reduction is well-documented, making a common cause less plausible. Option D is incorrect as it suggests unrelated causes, which is inconsistent with the context provided.

Q195. Read the passage and the following statements below. Then choose the correct option,basing your answer only on the information provided. Pakistan is rich in wildlife and culture. It is home to many sorts of wildlife,from the Ibex to the Indus River Dolphin ;and people from most countries in the world have made their home here. Statements :i. Pakistan is rich countryii. People from all nationalities of the world live in Pakistan.iii. Pakistan is home to at least one dolphin species.

• A. Only iii statement is correct✓
• B. Only i and ii are correct
• C. Only i and iii are correct
• D. Only ii and iii are correct

Explanation: Let's evaluate each statement based only on the passage:Statement i: "Pakistan is rich country" Incorrect. The passage says "Pakistan is rich in wildlife and culture", not in terms of wealth.Statement ii: "People from all nationalities of the world live in Pakistan." Incorrect. The passage says "people from most countries", not all nationalities.Statement iii: "Pakistan is home to at least one dolphin species." Correct. The passage specifically mentions the Indus River Dolphin, confirming this.Correct answer: Only statement iii is correct.

Q196. The quantity ∆φ/∆t has the same units as that of?

• A. Current
• B. Magnetic Induction
• C. Charge
• D. Emf✓

Explanation: Emf: Correct. According to Faraday’s Law, the rate of change of magnetic flux (Δϕ/Δt​) is directly related to the induced emf, which has units of volts (V) and matches the units of Δϕ/Δt

Q197. Choose the sentence that is grammatically correct:

• A. He weighed himself maunds.
• B. He weighed two maunds.✓
• C. He weighed themselves two.
• D. He weighed itself two maunds.

Explanation: This is the correct sentence. It clearly indicates that the weight of the person is being expressed in maunds, a unit of measure. The structure is grammatically sound.

Q198. Which of the following electronic configurations is correct for 24Cr?

• A. 1s2 2s2 2p6 3s2 3p6 3d5 4s¹✓
• B. 1s2,2s2,2p6,3s2,3p6,4s1,3d4
• C. 1s2,2s2,2p6, 3s2,3p6,3d6
• D. 1s2,2s2,2p6,3s2,3p6,4f6

Explanation: The atomic number of chromium (Cr) is 24. To determine its correct electron configuration, we can use the Aufbau principle, which states that electrons fill the lowest energy orbitals first. The electron configuration for chromium (Cr) is as follows:1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵So, the correct electronic configuration for chromium (Cr) is:1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵.