Punjab Mdcat 2025 — Solved Past Paper with Answers

Q1. Which of the following sentence has correct subject verb agreement?

• A. The teacher give the students homework.
• B. The teacher gives the students homework.✓
• C. The teachers gives the student homework.
• D. The teachers given the student homework.

Explanation: The correct answer is Option B: The teacher gives the students homework. In this sentence, 'teacher' is a singular noun, and the verb 'gives' correctly matches it in number. Options A and C are incorrect due to mismatches in subject-verb agreement: Option A uses the plural verb 'give' with a singular subject, while Option C uses the singular verb 'gives' with a plural subject. Option D is incorrect as it uses the past participle 'given' instead of the present tense 'give', which is necessary for the sentence to be grammatically correct.

Q2. The keys were found _ the drawer where you left them last week.

• A. under
• B. in✓
• C. on
• D. beside

Explanation: The correct answer is 'in' because it accurately describes the location of the keys as being within the confines of the drawer. The preposition 'in' indicates that something is contained or enclosed by something else, which is precisely the case here. The option 'under' suggests a position below the drawer, which is incorrect, as it does not match the description of the keys' location. Similarly, 'on' implies a surface-level placement and 'beside' indicates proximity but not containment, both of which do not fit the context of the sentence.

Q3. Identify the sentence among of the following, which is punctuated correctly?

• A. The teaching staff asked the principal what time the meeting would start.
• B. The teaching staff asked the principal: “What time would the meeting start”?
• C. The teaching staff asked the principal, “What time would the meeting start?✓
• D. The teaching staff asked the principal; “What time would the meeting start”?

Explanation: The correct answer is Option C. However, upon reviewing it, I noticed it also lacks a closing quotation mark and has a misplaced question mark. In a correctly punctuated sentence, the phrase should read: 'The teaching staff asked the principal, “What time would the meeting start?”' The other options are incorrect for the following reasons: Option A lacks quotation marks for the direct speech. Option B misuses a colon and has an incorrect question mark placement. Option D uses a semicolon incorrectly where a comma should be used and also has a misplaced question mark.

Q4. She was elated when she got first position In exams.” What is the meaning of “elated” In this sentence?

• A. Disappointed
• B. Worried
• C. Excited✓
• D. Mad

Explanation: The word 'elated' means to be very happy or excited, especially as a result of a success or achievement. In the context of the sentence, the speaker feels a strong sense of joy after receiving first position in their exams, which aligns perfectly with the meaning of 'excited.' The other options are incorrect because:Disappointed: This implies a feeling of sadness or regret, which contradicts the positive emotion described.Worried: This indicates a state of anxiety, which is not consistent with the joy of achieving a great accomplishment.Mad: This suggests a negative emotion, which is also contrary to the happiness conveyed by the term 'elated.'Thus, the correct answer is 'excited,' as it accurately reflects the positive feeling of elation.

Q5. The board of directors expressed _ disappointment with the financial results.

• A. their
• B. its✓
• C. his or her
• D. one’s

Explanation: 'Its' is the correct answer because it is the possessive adjective used for singular nouns or entities like 'board', indicating that the disappointment belongs to the board as a whole. The other options are incorrect because 'their' suggests a plural ownership, 'his or her' implies individual possession which does not fit the context of a collective group, and 'one’s' is too vague and informal for this setting.

Q6. It rained all night; _ the roads were flooded in the morning.

• A. similarly
• B. instead
• C. as a result✓
• D. in contrast

Explanation: The correct answer is as a result because it establishes a cause-and-effect relationship between the two clauses: the rain caused the roads to be flooded. The other options fail to convey this relationship: similarly suggests a comparison without causation; instead implies an alternative that contradicts the first clause; and in contrast indicates opposition, which is not applicable here.

Q7. The manager accepted the cashier’s _ for coming late.

• A. explanation✓
• B. explaination
• C. explenation
• D. explanasion

Explanation: The correct answer is 'explanation' because it is the noun that appropriately describes the reason the cashier is providing for being late. The sentence context suggests that the manager is accepting a justification, which aligns with the meaning of 'explanation.' The other options are all incorrect due to being misspellings of the word 'explanation,' which is essential for conveying the intended meaning in this scenario.

Q8. The writer has unearthed serious irregularities in the entire project. The word ‘unearthed’ in this sentence means

• A. written
• B. mentioned
• C. exposed✓
• D. created

Explanation: The correct answer is 'exposed' because in the context of the sentence, 'unearthed' refers to the act of revealing or uncovering serious irregularities within the project. The other options do not accurately represent this action: 'written' suggests documentation, 'mentioned' implies a casual reference, and 'created' indicates bringing something into existence, none of which match the meaning of discovering or revealing hidden problems.

Q9. Identify the sentence with no spelling error:

• A. Imtiaz invited me on a dinner party at the restaurant.✓
• B. Imtiaz invited me on a diner party at restaurant.
• C. Imtiaz invited me on a dinner party at resturant.
• D. Imtiaz invited me on a dinnner party at resturant.

Explanation: The correct answer is Option A because both 'dinner' and 'restaurant' are spelled correctly. Options B, C, and D all contain spelling errors: Option B incorrectly spells 'diner' instead of 'dinner' and omits 'the' before 'restaurant'; Option C misspells 'restaurant' as 'resturant'; and Option D has two errors, misspelling 'dinner' as 'dinnner' and 'restaurant' as 'resturant.' Therefore, Option A is the only choice without any spelling mistakes.

Q10. Which part of the brain contains central chemoreceptors that monitor CO2 levels in blood?

• A. Pons
• B. Midbrain
• C. Hypothalamus
• D. Medulla oblongata✓

Explanation: The correct answer is the medulla oblongata, which contains central chemoreceptors that are sensitive to changes in carbon dioxide levels in the blood. This region of the brain is essential for regulating breathing and maintaining homeostasis in blood gas levels. In contrast, the pons is primarily responsible for relaying messages between different parts of the brain and does not monitor blood chemistry. The midbrain is involved in functions such as vision and hearing, and the hypothalamus regulates various bodily functions but does not contain the chemoreceptors for CO2.

Q11. Which component of a reflex arc connects the sensory neuron to the motor neuron within the spinal cord?

• A. Receptor
• B. Effector
• C. Muscle fiber
• D. Associative neuron✓

Explanation: The correct answer is Associative neuron (Option D), which serves as a connector between the sensory neuron that receives the stimulus and the motor neuron that elicits a response. The associative neuron processes the information and facilitates communication between these two types of neurons within the spinal cord, allowing for a quick reflex action.Options A, B, and C are incorrect because:Receptor: While it detects the stimulus, it does not connect neurons.Effector: This refers to the muscle or gland that executes the response, not the connector in the reflex arc.Muscle fiber: Muscle fibers are the effectors of the reflex action, responding to signals from the motor neuron, not connecting neurons.

Q12. The 9.3.3.1 ratio of law of Independent assortment can be affected by

• A. Genetic drift
• B. Small population
• C. Gene linkage✓
• D. Gene duplication

Explanation: The correct answer is Gene linkage because it describes how genes that are physically close on the same chromosome tend to be inherited together, which can alter the expected ratios from independent assortment. The expected 9.3.3.1 ratio assumes that genes assort independently, but when genes are linked, they do not segregate independently during meiosis. The other options are incorrect for the following reasons: Genetic drift influences allele frequencies in populations but does not directly affect the expected ratios of inheritance. Small population refers to the population size and its impact on genetic variance, but it does not inherently change the inheritance ratios without the context of linkage. Gene duplication increases gene number but does not impact the way alleles are distributed during gamete formation regarding the independent assortment principle.

Q13. Best description of the process of crossing over during meiosis:

• A. Duplication of chromosome
• B. Exchange of genes between non-sister chromatids✓
• C. Movement of chromosome to opposite poles
• D. Separation of sister chromatids

Explanation: Crossing over is a vital process that occurs during prophase I of meiosis, where homologous chromosomes pair and exchange segments of genetic material between non-sister chromatids. This genetic exchange increases genetic diversity in gametes. The correct answer is option B, as it accurately reflects this definition of crossing over. Options A, C, and D describe different processes related to meiosis but do not pertain to crossing over. Option A discusses chromosome duplication, which occurs before meiosis begins. Option C refers to the movement of chromosomes during anaphase, while option D addresses the separation of sister chromatids during anaphase II, neither of which involves the exchange of genetic material.

Q14. Total number of linkage groups in a normal human is:

• A. 02
• B. 23✓
• C. 46
• D. 92

Explanation: The correct answer is 23, as humans possess 23 pairs of chromosomes, which corresponds to 23 distinct linkage groups. Each linkage group consists of genes located on the same chromosome that tend to be inherited together due to their proximity. Options 02, 46, and 92 are incorrect because they either misinterpret the concept of linkage groups or refer to the total number of chromosomes rather than the number of linkage groups, which directly reflects the number of chromosomes present in an organism.

Q15. Nissls granule is a specialized structure in neuron formed by modification of

• A. Golgi bodies & Smooth ER
• B. Peroxisome & Mitochondria
• C. Lysosome & Vacuole
• D. Ribosome & Rough ER✓

Explanation: Nissl granules are specialized structures found in neurons that are primarily composed of ribosomes and rough endoplasmic reticulum (Rough ER). These structures are crucial for the synthesis of proteins, which are vital for the functioning of neurons. The ribosomes are responsible for translating mRNA into proteins, while the rough ER serves as the site for processing these proteins before they are transported to their final destinations. The other options are incorrect because: Golgi bodies and Smooth ER are involved in protein modification and lipid synthesis, respectively, but are not directly responsible for Nissl granule formation. Peroxisomes and mitochondria have different roles in metabolism and energy production, with no connection to the formation of Nissl granules. Lysosomes and vacuoles perform functions related to waste disposal and storage, and do not contribute to the production of Nissl granules. Therefore, the correct answer is the option that includes ribosomes and rough ER.

Q16. What is the function of a centromere?

• A. To protect the ends of chromosomes
• B. To hold sister chromatids together✓
• C. To carry genetic information
• D. To initiate DNA replication

Explanation: The centromere is a vital part of the chromosome that serves as the attachment point for spindle fibers during cell division, specifically during mitosis and meiosis. It is responsible for holding sister chromatids together until they are separated into two daughter cells. While telomeres protect the chromosome ends, the centromere ensures that each daughter cell receives the correct number of chromosomes. Options A, C, and D describe functions unrelated to the centromere; A discusses telomeres, C refers to the genetic material itself, and D pertains to the initiation of DNA replication, which occurs at different sites on the DNA molecule.

Q17. All are the functions of lysosome EXCEPT:

• A. Intra cellular digestion
• B. Removal of the waste
• C. Autophagy
• D. Lipid synthesis✓

Explanation: The correct answer is Lipid synthesis because lysosomes are not involved in the synthesis of lipids; instead, they are responsible for digestion and waste removal within the cell. The other options—intracellular digestion, waste removal, and autophagy—are all functions associated with lysosomes. Lysosomes contain hydrolytic enzymes that break down various biomolecules, thus playing a fundamental role in maintaining cellular health by removing waste and recycling components.

Q18. Kidneys perform their osmoregulatory role under the effect of Antidiuretic Hormone, which type of urine is produced in this situation?

• A. Hypotonic urine with decreased volume
• B. Hypotonic urine with increased volume
• C. Hypertonic urine with decreased volume✓
• D. Hypertonic urine with increased volume

Explanation: Antidiuretic Hormone (ADH) plays a crucial role in osmoregulation by increasing the permeability of the kidney tubules to water, allowing more water to be reabsorbed back into the bloodstream. When ADH is active, the kidneys produce urine that is hypertonic (concentrated) and in reduced volume due to effective water retention. Therefore, the correct answer is Hypertonic urine with decreased volume (Option C). Options A and B are incorrect as they describe hypotonic urine, which is not produced under the effect of ADH. Option D is also incorrect because, despite indicating hypertonicity, it suggests increased volume, which opposes the action of ADH.

Q19. Which part of brain controls transition between sleeping and wakefulness?

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

Explanation: The correct answer is the pons, which is part of the brainstem and is essential for regulating sleep cycles. It facilitates communication between different parts of the brain and helps manage the transition between sleep and wakefulness. The pons specifically plays a significant role in the regulation of REM sleep, which is a critical phase of the sleep cycle. In contrast, the medulla oblongata is responsible for autonomic functions, such as heart rate and breathing, and does not directly influence sleep patterns. The cerebellum is mainly involved in coordination and balance, with no direct connection to sleep regulation. Lastly, while the cerebrum is involved in many higher cognitive functions, it does not specifically control the sleep-wake transition.

Q20. The first consequence of lymphatic blockage in tissues is

• A. Deficiency of oxygen
• B. Loss of nerve signals
• C. Drop in blood pressure
• D. Excess fluid accumulation in tissue✓

Explanation: The correct answer is Excess fluid accumulation in tissue. The lymphatic system plays a crucial role in draining excess fluid from tissues. When there is a blockage, this fluid cannot be properly drained, leading to edema, which is the accumulation of fluid in the interstitial spaces. The other options are incorrect as they do not directly relate to the primary function of the lymphatic system or the immediate consequence of its blockage. A deficiency of oxygen is primarily linked to blood supply issues, loss of nerve signals pertains to nervous system function, and a drop in blood pressure is not an immediate result of lymphatic failure.

Q21. Which of the following is the auditory relay Centre and Centre that controls reflex movement of eyes?

• A. Forebrain
• B. Cerebellum
• C. Midbrain✓
• D. Cerebellum

Explanation: The correct answer is the midbrain. The midbrain houses important structures such as the inferior colliculus, which is key for auditory processing, and the superior colliculus, which is involved in reflexive eye movements. This dual functionality makes the midbrain the central hub for these specific tasks.The forebrain is primarily responsible for complex cognitive functions and sensory perception but does not play a significant role in auditory relay or eye reflexes. The cerebellum is essential for motor coordination and balance but does not directly pertain to auditory processing or reflexive eye movements.Thus, the midbrain is uniquely suited to fulfill the requirements described in the question.

Q22. Which of the following is the correct pathway of nerve impulse?

• A. Receptors-- CNS-- Effectors✓
• B. Effectors -- Receptors -- CNS
• C. CNS-- Effectors-- Receptors
• D. Effectors -- CNS -- Receptors

Explanation: The correct pathway of a nerve impulse is Receptors -- CNS -- Effectors. This means that when a stimulus is detected by receptors, it sends a signal to the central nervous system (CNS) for processing. The CNS then communicates with effectors, which are the muscles or glands that carry out the response. The other options are incorrect as they rearrange this order and misrepresent the roles of receptors and effectors in the nerve impulse pathway.

Q23. The neurotransmitters are secreted by the neuron from:

• A. Axon ends✓
• B. Dendrite end
• C. Nissls granules
• D. Cell body

Explanation: The correct answer is Axon ends because neurotransmitters are released from the axon terminals of neurons into the synaptic cleft, where they facilitate communication between neurons. The other options are incorrect because:Dendrite end: Dendrites receive neurotransmitters but do not release them.Nissls granules: These are involved in protein synthesis and not in the secretion of neurotransmitters.Cell body: The cell body is responsible for maintaining the neuron and processing signals but does not secrete neurotransmitters.Understanding the role of different parts of the neuron is essential for grasping how neural communication occurs.

Q24. The pubic symphysis is a slightly moveable joint joined by which of the following tissue?

• A. Elastic cartilage
• B. Fibrocartilage✓
• C. Costal cartilage
• D. Articular cartilage

Explanation: The pubic symphysis is a slightly movable joint located between the left and right pubic bones. It is primarily composed of fibrocartilage, which provides both strength and limited flexibility, allowing for slight movement during activities such as walking and childbirth. This type of cartilage is crucial in joints that experience pressure but require some degree of movement. The other options are incorrect because:Elastic cartilage is not found in the pubic symphysis; it is more flexible and supports structures that require elasticity.Costal cartilage is used in connecting ribs to the sternum and does not provide the structure for the pubic symphysis.Articular cartilage is found at the ends of bones in synovial joints, serving a different function than the fibrocartilage of the pubic symphysis.

Q25. Hippocampus plays an important role in the:

• A. Formation of short-term memory
• B. Formation of image on retina
• C. Formation of long-term memory✓
• D. Formation of emotions

Explanation: The hippocampus is critical for the formation of long-term memories. It helps process and store information that will be retained over time. While some functions like short-term memory formation and emotional responses are related to memory, the hippocampus's primary role is in long-term memory consolidation. The options regarding the formation of images on the retina and the formation of emotions are incorrect, as these functions are associated with different parts of the brain. The visual system handles image formation, while the amygdala is more directly involved in emotional processing.

Q26. In a pea plant seed color is determined by one gene, with yellow (dominant) and green (recessive). Which parental cross would most likely result in offspring showing a 1:1 ratio of yellow to green seeds?

• A. YY x YY
• B. Yy x yy✓
• C. Yy x Yy
• D. YY x yy

Explanation: The correct answer is Option B: Yy x yy, which produces a 1:1 ratio of yellow to green seeds. In this scenario, the Yy parent can contribute either a dominant yellow allele (Y) or a recessive green allele (y), while the yy parent can only contribute recessive alleles. This results in half of the offspring being yellow (Yy) and half being green (yy). In contrast, Option A (YY x YY) and Option D (YY x yy) would produce only yellow seeds, resulting in a 100% yellow phenotype. Option C (Yy x Yy) leads to a 3:1 ratio of yellow to green seeds, which does not satisfy the condition of a 1:1 ratio.

Q27. Enzymes activity decreases at very low or high pH because:

• A. Substrate concentration increases
• B. Enzymes become denatured✓
• C. Product formation increases
• D. Temperature becomes constant

Explanation: Enzymes are highly sensitive to pH changes, as extreme pH levels can lead to denaturation, a process where the enzyme's active site is altered, preventing substrate binding and thus inhibiting the reaction. Option B correctly identifies this phenomenon. Options A and C are incorrect because they suggest that changes in substrate concentration or product formation are the primary factors affecting enzyme activity at extreme pH levels, which is not accurate. Option D is also incorrect, as the constancy of temperature does not directly relate to the impact of pH on enzyme denaturation.

Q28. The complementary base pairing in DNA is important because it:

• A. Maintains the tertiary structure of enzymes
• B. Provides energy for all cell metabolism
• C. Enables protein to fold properly
• D. Allows DNA to act as a genetic blueprint during replication✓

Explanation: The correct answer is that complementary base pairing allows DNA to act as a genetic blueprint during replication. This process involves the pairing of adenine with thymine and cytosine with guanine, which ensures that each new DNA strand is an exact copy of the original strand. This precision is crucial for maintaining the integrity of genetic information across generations.In contrast, the incorrect options do not accurately reflect the role of DNA or complementary base pairing. The first option relates to enzyme structure, which is irrelevant to DNA's function. The second option misrepresents DNA's role in metabolism, as it does not provide energy. The third option suggests that DNA directly influences protein folding, which occurs post-translation through different biochemical processes.

Q29. Mendel crossed a plant with round yellow seeds (RRYY) and was a plant with wrinkled green seeds (rryy), what was the phenotype of all F1 offspring?

• A. All round green
• B. All round yellow✓
• C. All wrinkled yellow
• D. All wrinkled green

Explanation: Mendel's cross between a plant with round yellow seeds (RRYY) and a plant with wrinkled green seeds (rryy) results in F1 offspring that all express the dominant traits. In this case, 'round' (R) and 'yellow' (Y) are dominant traits. The F1 generation will inherit one allele from each parent, resulting in a genotype of RrYy, which expresses the phenotype of all round yellow seeds. The other options are incorrect because they either include recessive traits that cannot express themselves in the presence of dominant traits or incorrectly combine phenotypes that do not match the dominant characteristics of the F1 generation.

Q30. A mature duplicated chromosome consists of:

• A. Two identical double helical DNA molecules✓
• B. Two different double helical DNA molecules
• C. A double helical DNA molecule distributed in both chromatids
• D. Histone chains wrapped around DNA core

Explanation: A mature duplicated chromosome consists of two identical double helical DNA molecules, known as sister chromatids, which are connected at a region called the centromere. Each chromatid contains an exact copy of the genetic information, ensuring that when the cell divides, each daughter cell receives an identical set of chromosomes. The other options are incorrect because they either describe different DNA molecules, misrepresent the structure of chromatids, or focus on the role of histones rather than the chromosomes themselves.

Q31. Which set of quantum numbers is not allowed for an electron.

• A. {n}=1, {l}=0, {m}=0, {s}=+1/2
• B. {n}=3, {l}=0,{m}=0,{s}=-1/2
• C. {n}=2,{l}=2, {m}=1, {s}=+1/2✓
• D. {n}=1,{l}=0, {m}=0, {s}=+1/2

Explanation: The correct answer is Option C, {n}=2,{l}=2, {m}=1, {s}=+1/2, because the azimuthal quantum number (l) must always be less than the principal quantum number (n). In this case, l=2 is not valid for n=2. Options A, B, and D are all valid sets of quantum numbers. In Option A, l=0 is acceptable for n=1; in Option B, l=0 is also acceptable for n=3; and in Option D, the values follow all allowable rules for quantum numbers as well.

Q32. The most primitive respiratory process occurring in a living cell is;

• A. Lactic acid fermentation
• B. Alcoholic fermentation
• C. Glycolysis✓
• D. Krebs's cycle

Explanation: Glycolysis is the correct answer because it is the most primitive form of respiration, occurring in the cytoplasm of cells and not requiring oxygen. It is the first step of both aerobic and anaerobic respiration and has been preserved throughout evolution due to its efficiency in generating energy. The other options, such as lactic acid fermentation and alcoholic fermentation, are both anaerobic processes but are considered more specialized forms of respiration. The Krebs cycle, on the other hand, requires oxygen and occurs in the mitochondria, making it a more advanced metabolic pathway that evolved later.

Q33. In normal 28 days menstrual cycle when would you expect the LH surge to occur?

• A. Days 7-10
• B. Days 11-14✓
• C. Days 15-18
• D. Days 19-22

Explanation: The correct answer is Days 11-14. During a normal 28-day menstrual cycle, the LH (luteinizing hormone) surge is crucial for triggering ovulation, which typically occurs about midway through the cycle. This LH surge usually peaks around days 11 to 14. Options Days 7-10, Days 15-18, and Days 19-22 are incorrect because they occur either too early in the follicular phase or too late in the luteal phase, after ovulation has already occurred.

Q34. Receive, retain and nourish a fertilized ovum is the main function of:

• A. Cervix
• B. Uterus✓
• C. Ovary
• D. Oviduct

Explanation: The uterus is the organ responsible for receiving, retaining, and nourishing a fertilized ovum, providing the necessary environment for embryo development throughout pregnancy. The cervix, while part of the reproductive system, functions mainly as a passageway and does not nourish the fertilized ovum. The ovaries produce eggs and hormones but do not support fertilization post-ovulation. The oviduct is crucial for the initial stage of fertilization but does not serve as a nurturing environment for the embryo after fertilization occurs.

Q35. Which property of water helps in moderating Earth's climate and maintaining stable temperature in aquatic environment?

• A. Low viscosity
• B. High surface tension
• C. High specific heat✓
• D. High density

Explanation: The correct answer is High specific heat. This property of water allows it to absorb and retain heat, which helps to moderate the climate by preventing extreme temperature fluctuations. In aquatic environments, this leads to stable temperatures that are conducive to life. The other options, while important properties of water, do not contribute directly to climate moderation or maintaining stable temperatures: Low viscosity facilitates flow but does not regulate temperature, High surface tension affects surface interactions but not climate, and High density influences buoyancy rather than temperature regulation.

Q36. The primary function of larynx is:

• A. Humidifying air
• B. Filtering dust
• C. Gaseous exchange
• D. Voice production✓

Explanation: The correct answer is Voice production. The larynx, which contains the vocal cords, is essential for producing sound and enabling speech. It acts as a passage for air and is involved in the modulation of voice, making it the primary function of the larynx.Option A, Humidifying air, is incorrect as this function is mainly carried out by the nasal passages. Option B, Filtering dust, is also incorrect because dust filtration is primarily the responsibility of the nasal cavity and upper respiratory tract. Option C, Gaseous exchange, is not the function of the larynx, as gaseous exchange occurs in the alveoli of the lungs.

Q37. During menstrual cycle, luteinizing hormone (LH) is secreted due to;

• A. Decrease in Estrogen
• B. Decrease in FSH✓
• C. Increase in FSH
• D. Environmental effect

Explanation: Luteinizing hormone (LH) is primarily responsible for triggering ovulation in the menstrual cycle. It is secreted in response to a decrease in follicle-stimulating hormone (FSH) levels. This decrease can indicate that the body is ready to ovulate and thus stimulates the release of LH from the anterior pituitary gland. The other options are incorrect for the following reasons: - A decrease in estrogen typically occurs after ovulation, not in the lead-up to it, and does not trigger LH secretion. - An increase in FSH does not lead to LH secretion; rather, LH levels rise when FSH levels drop. - While environmental effects can indirectly influence hormone levels, they are not the primary drivers of LH secretion during the menstrual cycle.

Q38. Effect of increased substrate concentration on enzyme activity:

• A. Increases the rate of reaction
• B. Increases the rate of reaction until active sites are saturated✓
• C. Have no effect on the reaction rate
• D. All of these

Explanation: The correct answer is Option B, which states that increasing substrate concentration raises the rate of reaction until the enzyme's active sites are saturated. Enzymes can only catalyze a certain amount of substrate at any given time, and once all active sites are occupied, the reaction rate levels off. Option A is incorrect because it overlooks the saturation point. Option C is incorrect as substrate concentration does have a significant impact on enzyme activity. Option D is also wrong, as it suggests that all previous statements are true, which they are not.

Q39. An oligosaccharide is made up of at least:

• A. Two saccharide units✓
• B. Three saccharide units
• C. Three to ten saccharide units
• D. More than ten saccharide units

Explanation: An oligosaccharide is defined as a carbohydrate composed of 2 to 10 monosaccharide units. Therefore, the correct answer is that it is made up of at least two saccharide units. Options B and C, while containing valid information about larger numbers of units, do not meet the definition's minimum threshold. Option D is incorrect as it exceeds the maximum limit for oligosaccharides and falls into the category of polysaccharides.

Q40. Left and right cerebral hemispheres are connected with each other by:

• A. Corpus luteum
• B. Corpus callosum✓
• C. A band of dendrites
• D. Dorsal and ventral nerve roots

Explanation: The correct answer is the corpus callosum, which is a crucial structure in the brain that connects the left and right cerebral hemispheres, allowing for inter-hemispheric communication. The corpus luteum, on the other hand, is related to reproductive functions and has no role in brain connectivity. A band of dendrites refers to neuronal extensions and does not pertain to structural connections between hemispheres. Lastly, dorsal and ventral nerve roots are part of the peripheral nervous system, not the cerebral structure, making them irrelevant in this context.

Q41. Which is the common feature between cardiac and smooth muscles?

• A. Voluntary
• B. Involuntary✓
• C. Branched
• D. Unbranched

Explanation: The correct answer is Involuntary because both cardiac and smooth muscles function automatically without conscious effort. Cardiac muscle is found in the heart and is responsible for pumping blood, while smooth muscle is found in various internal organs and helps facilitate involuntary movements such as digestion. The other options are not correct: Voluntary is incorrect because it applies to skeletal muscles, Branched is incorrect as it only applies to cardiac muscles, and Unbranched applies solely to smooth muscles. Thus, the common feature between cardiac and smooth muscles is their involuntary nature.

Q42. Which statement best explains the difference between humoral and cell mediated immune responses?

• A. Humoral immunity involves B-lymphocytes and cell mediated immunity involves T-lymphocytes✓
• B. Humoral immunity destroys viruses and cell mediated immunity destroys bacteria
• C. Humoral immunity is specific and cell mediated immunity is nonspecific
• D. Humoral immunity uses antibodies and cell mediated immunity does not involve immune cells

Explanation: The correct answer is Option A: Humoral immunity involves B-lymphocytes and cell mediated immunity involves T-lymphocytes. This accurately reflects the primary functions of B and T cells in the immune response, with B-lymphocytes responsible for antibody production in humoral immunity and T-lymphocytes involved in directly attacking infected cells in cell-mediated immunity.Option B is incorrect because both immune responses can target different types of pathogens, not strictly separating their functions by pathogen type. Option C is wrong as both responses are specific to their targets. Lastly, Option D misrepresents cell-mediated immunity, which is indeed reliant on immune cells.

Q43. The Joints which cause rotational movements are

• A. Hinge
• B. Ball and Socket✓
• C. Cartilage
• D. Sutures

Explanation: The correct answer is Ball and Socket joints, which are characterized by a spherical bone head fitting into a cup-like socket of another bone, allowing for rotational movements as well as movement in multiple planes. Examples include the shoulder and hip joints. In contrast, Hinge joints (like the elbow and knee) allow primarily for back-and-forth motion but not rotation. Cartilage is not a joint type but rather a type of connective tissue that provides cushioning at the ends of bones in a joint. Sutures are immovable joints found between the bones of the skull that do not allow for rotation or significant movement at all.

Q44. Self-fertilization in plants through successive generations can lead to the development of:

• A. Hybrid breeds of plants
• B. Variations in coming generation
• C. True breeding plants✓
• D. Adaptation with their environment

Explanation: Self-fertilization in plants occurs when a flower's pollen fertilizes its ovules, leading to offspring that have a genetic makeup similar to the parent plant. Over successive generations, this process tends to stabilize certain traits, resulting in 'true breeding' plants that consistently express those traits when they self-fertilize. This is because self-fertilization reduces genetic diversity, allowing specific traits to become fixed within the population.In contrast, option A is incorrect since hybrid breeds require crossing different varieties, not self-fertilization. Option B is misleading as self-fertilization typically reduces variation rather than increases it. Option D misrepresents the nature of self-fertilization, as it does not inherently promote adaptation; rather, it stabilizes existing traits.

Q45. FISCHER ESTERIFICATION is which type of reaction

• A. Condensation✓
• B. Substitution
• C. Elimination
• D. Hydrogenation

Explanation: Fischer esterification is a type of condensation reaction where a carboxylic acid reacts with an alcohol, resulting in the formation of an ester and the release of a water molecule. In this process, the -OH group from the carboxylic acid and a hydrogen atom from the alcohol are removed, leading to the formation of the ester bond. Option A is correct since it accurately describes the nature of the reaction. Options B, C, and D are incorrect because they describe different types of chemical reactions that do not apply to the Fischer esterification process.

Q46. Which part of the neuron typically receives incoming signals from other neurons?

• A. Axon
• B. Dendrites✓
• C. Myelin sheath
• D. Synaptic knob

Explanation: The correct answer is Dendrites, as they are specifically designed to receive incoming signals from other neurons. Dendrites increase the surface area of the neuron, allowing it to make connections with many other neurons. In contrast, the axon is responsible for sending signals away from the neuron, the myelin sheath serves as insulation for the axon to enhance signal transmission speed, and the synaptic knob is involved in the release of neurotransmitters to communicate with other neurons, not in receiving signals.

Q47. Why thick filaments are unable to bind with thin filament in a relaxed muscle fiber?

• A. Actin blocks the myosin binding site
• B. Tropomyosin blocks the myosin binding site✓
• C. Troponin blocks the myosin binding site
• D. Tropomyosin blocks the troponin binding site

Explanation: The correct answer is that tropomyosin blocks the myosin binding site on actin in a relaxed muscle fiber. In this state, the tropomyosin protein covers the binding sites on actin, preventing the myosin heads from attaching and initiating contraction. When muscle contraction is triggered by calcium ions, troponin binds calcium and causes a conformational change that moves tropomyosin away from the binding sites, allowing myosin to bind to actin.Option A is incorrect because actin itself does not block the binding sites; it is the tropomyosin that does this. Option C is incorrect as troponin does not block the binding site but is instead involved in the regulatory mechanism. Option D is also incorrect because tropomyosin does not block the binding site on troponin; rather, it regulates the binding sites on actin.

Q48. Which of the following is the correct higher (left) to lower (right) sequence of molecules involved in the flow of genetic information in the cell?

• A. DNA → rRNA → tRNA → mRNA✓
• B. rRNA → tRNA → mRNA → DNA
• C. mRNA → tRNA → rRNA →DNA
• D. DNA → mRNA → rRNA → tRNA

Q49. A person in hot weather is unable to maintain body temperature. Which physiological response is absent?

• A. Vasodilation & sweating✓
• B. Vasodilation
• C. Sweating
• D. Vasoconstriction

Explanation: In hot weather, the body employs various physiological responses to maintain homeostasis and regulate temperature. The absence of vasodilation and sweating would prevent effective heat loss, leading to overheating. Vasodilation increases blood flow to the skin, allowing heat to dissipate, while sweating helps cool the body through evaporative cooling. The other options are incorrect: vasodilation alone is insufficient without sweating, sweating alone may not be effective without vasodilation, and vasoconstriction is counterproductive in hot conditions as it reduces blood flow to the skin, making it harder to release heat.

Q50. Which of the following best highlights the importance of proteins in immunity?

• A. They act as receptors of pathogens
• B. They are long term energy reserves
• C. They act as antibodies✓
• D. They act as mechanical barrier for pathogens

Explanation: The correct answer is that proteins act as antibodies. Antibodies are specialized proteins produced by the immune system to identify and neutralize foreign objects like bacteria and viruses. They are critical for the adaptive immune response, providing specificity to the immune attack. Option A is incorrect because while some proteins do function as receptors for recognizing pathogens, this is not their predominant role in immunity. Option B is incorrect as proteins are not primarily long-term energy reserves; this function is more associated with carbohydrates and fats. Option D is also incorrect because it misrepresents the role of proteins; while proteins can form part of the immune response, mechanical barriers like skin provide the first line of defense against pathogens.

Q51. The secondary structure of proteins is stabilized by:

• A. Ionic bonds
• B. Hydrogen bonds✓
• C. Disulfide bridges
• D. Hydrophobic exclusion

Explanation: The correct answer is Hydrogen bonds because they play a crucial role in stabilizing the secondary structure of proteins, which includes configurations like alpha helices and beta sheets. These bonds form between the hydrogen atom of one amino acid's backbone and the oxygen atom of another, facilitating the formation of these structures. Ionic bonds, disulfide bridges, and hydrophobic exclusion are important for the tertiary and quaternary structures but do not stabilize the secondary structure itself.

Q52. The following is an example of a globular protein

• A. Keratin
• B. Collagen
• C. Hemoglobin✓
• D. Histone

Explanation: Hemoglobin is classified as a globular protein due to its compact, spherical structure and solubility in water, which allows it to effectively transport oxygen in the bloodstream. In contrast, keratin and collagen are fibrous proteins, characterized by their elongated structures and insolubility, serving primarily structural roles in the body. Histones, while important for DNA packaging, do not fit the definition of globular proteins either, as they are more involved in structural and regulatory functions rather than the physiological roles typical of globular proteins.

Q53. The main idea in Darwin's Theory of "Origin of species by natural selection" is:

• A. Inheritance of acquired traits
• B. Use and disuse of organs
• C. Species never change
• D. Evolution occurs through gradual accumulation of adaptation through successive generations✓

Explanation: The correct answer is Option D, which captures the fundamental principle of Darwin's theory of evolution through natural selection. Darwin proposed that organisms with traits better suited to their environments are more likely to survive and reproduce, leading to the gradual accumulation of these advantageous adaptations over generations. Option A is incorrect because the idea of inheritance of acquired traits was a theory proposed by Lamarck, not Darwin. Option B is also incorrect as it refers to Lamarck's concept of use and disuse, which is not part of Darwin's theory. Option C is incorrect because it fundamentally misrepresents Darwin's view; he argued that species do change over time, contrary to the assertion that they never change.

Q54. The process of osmoregulation refers to:

• A. The filtration of blood to remove metabolic waste
• B. The regulation of solute and water movement between an organism and its environment✓
• C. The creation of an osmotic gradient in the kidney medulla
• D. The secretion of hormones that control blood plasma

Explanation: The correct answer is Option B, which defines osmoregulation as the regulation of solute and water movement between an organism and its environment. This process is essential for maintaining homeostasis, as it ensures that cells and bodily fluids remain at optimal concentrations of solutes. Option A is incorrect because it focuses on blood filtration rather than the balance of solutes and water. Option C, while related to kidney function, describes a specific mechanism rather than the overall process of osmoregulation. Option D discusses hormonal control that may influence plasma composition but does not encompass the broader concept of regulating water and solute balance.

Q55. A baby girl is born with hemophilia, which is an X-linked recessive disorder. What are the most likely genotypes of her parents?

• A. The mother is a carrier and the father is normal
• B. The mother is hemophiliac and the father is normal
• C. The mother is a carrier and the father is hemophiliac✓
• D. Both are normal

Explanation: The correct answer is that the mother is a carrier and the father is hemophiliac. In X-linked recessive disorders like hemophilia, a female must inherit two copies of the affected gene (one from each parent) to express the disorder. The mother, being a carrier, has one normal X chromosome and one affected X chromosome (XHXh), which would allow her to pass on the affected allele. The father, who is hemophiliac, has only one X chromosome (XhY) and will pass on that affected X chromosome to his daughters. Therefore, their daughter could inherit an affected X from both parents, resulting in hemophilia. The other options are incorrect because the combinations either do not allow for a daughter to inherit the disorder or do not account for the necessary alleles for the daughter to express hemophilia.

Q56. Which of the following is a key feature of RNA?

• A. Deoxyribose and thymine
• B. Ribose stranded and thymine
• C. Ribose and uracil✓
• D. Ribose and adenine

Explanation: The correct answer is Option C: Ribose and uracil. RNA is characterized by the presence of ribose sugar, which differentiates it from DNA, which contains deoxyribose. Additionally, RNA includes uracil as a nitrogenous base instead of thymine, which is present in DNA. Option A is incorrect because it describes DNA components. Option B incorrectly uses the term 'stranded' and also mentions thymine, making it incorrect. Option D is partially correct since it mentions ribose, but it does not fully capture the defining features of RNA since adenine is also a component of DNA.

Q57. Which of the following types of RNA makeup the largest proportion of total cellular RNA?

• A. Messenger RNA
• B. Ribosomal RNA✓
• C. Transfer RNA
• D. Catalytic RNA (ribozyme)

Explanation: The correct answer is Ribosomal RNA (rRNA), as it constitutes the largest proportion of total cellular RNA, making up about 80% of the RNA in a typical cell. It plays an essential role in the structure and function of ribosomes, which are responsible for protein synthesis.Messenger RNA (mRNA) is crucial for conveying genetic information from DNA but only accounts for about 1-5% of total RNA in a cell. Transfer RNA (tRNA) facilitates the translation of mRNA into proteins and also makes up a smaller percentage of total RNA. Catalytic RNA (ribozyme) is specialized RNA with catalytic functions but is present in very minute quantities compared to the other types of RNA.

Q58. Identify the most appropriate function of chromosomes

• A. Energy production and storage
• B. Protein synthesis and regulation
• C. Storage of genetic information✓
• D. Lipid metabolism and transport

Explanation: Chromosomes are essential components of cellular biology, primarily serving the function of storing genetic information in the form of DNA. This genetic information is crucial for the development, growth, reproduction, and functioning of living organisms. The correct answer, 'Storage of genetic information', highlights this fundamental role of chromosomes. Option A, 'Energy production and storage', is incorrect as it pertains to cellular processes involving mitochondria and other organelles, not chromosomes. Option B, 'Protein synthesis and regulation', while relevant since chromosomes contain genes that are transcribed into mRNA for protein production, misrepresents the primary function of chromosomes. They do not directly synthesize proteins but rather house the genetic instructions for such processes. Option D, 'Lipid metabolism and transport', is also incorrect; chromosomes have no involvement in lipid metabolism or transport, which are functions carried out by other cellular components.

Q59. The bacterium Treponema Pallidum is responsible for which sexually transmitted disease?

• A. Syphilis✓
• B. Chlamydia
• C. Gonorrhea
• D. Genital herpes

Explanation: The correct answer is Syphilis, as it is specifically caused by the bacterium Treponema Pallidum. Syphilis can present in multiple stages and lead to severe health issues if untreated, including damage to the heart and brain.The other options are incorrect because:Chlamydia is caused by Chlamydia trachomatis, a different bacterium.Gonorrhea is caused by Neisseria gonorrhoeae, which is also not related to Treponema Pallidum.Genital herpes is caused by the herpes simplex virus, further distinguishing it from syphilis.

Q60. Enzymes belong to which class of biomolecules?

• A. Carbohydrates
• B. Lipids
• C. Proteins✓
• D. Nucleic acids

Explanation: Enzymes are specialized proteins that catalyze biochemical reactions, making them crucial for various metabolic processes. Among the options provided, only proteins are classified as enzymes. Carbohydrates primarily serve as energy sources and structural components, lipids are used for energy storage and membrane formation, and nucleic acids are responsible for genetic information. Thus, the correct answer is Proteins.

Q61. _ arranges the DNA into the chromosomes in a eukaryotic cell

• A. Hormones
• B. Elastin
• C. Histone✓
• D. Nucleosome

Explanation: Histones are essential proteins that play a crucial role in the packaging of DNA into chromatin, which is further organized into chromosomes in eukaryotic cells. They facilitate the compaction of DNA, making it possible to fit lengthy strands within the nucleus. Other options are incorrect because hormones and elastin do not relate to chromosomal structure, while nucleosomes represent the structural unit formed by histones and DNA, rather than the agents arranging DNA into chromosomes.

Q62. Tissue fluid in a lymphatic system is called as:

• A. Plasma
• B. Matrix
• C. Lymph✓
• D. Blood

Explanation: The correct answer is Lymph, which is the fluid that circulates in the lymphatic system. Lymph is derived from tissue fluid, which is formed when plasma leaves the blood vessels and bathes the cells in tissues. It collects in lymphatic vessels and is transported back into the bloodstream. Other options are incorrect: Plasma is the liquid part of blood, not found in the lymphatic system; Matrix does not specifically refer to any fluid but rather the structural material; and Blood is the fluid of the circulatory system, separate from lymph.

Q63. The function of nucleolus is to make:

• A. rDNA
• B. Lysosomes
• C. Ribosomes✓
• D. Chromosomes

Explanation: The correct answer is Ribosomes because the nucleolus is specifically tasked with synthesizing ribosomal RNA (rRNA) and assembling it with proteins to form the ribosomal subunits necessary for protein synthesis. The other options are incorrect: rDNA refers to the genetic material that encodes rRNA but is not directly produced by the nucleolus, Lysosomes are formed in the Golgi apparatus and are involved in digestion, and Chromosomes are structures that contain DNA and are formed during cell division, but they are not made by the nucleolus.

Q64. Which one of the following biomolecules is a polymer/polysaccharide?

• A. Sucrose
• B. Pentose
• C. Lactose
• D. Glycogen✓

Explanation: The correct answer is Glycogen, as it is a polysaccharide composed of many glucose monomers linked together, forming a complex carbohydrate that serves as stored energy in animals. In contrast, Sucrose and Lactose are both disaccharides, consisting of just two sugar units, and Pentose is a type of monosaccharide with five carbon atoms, which does not fit the definition of a polymer/polysaccharide. Understanding the distinction between monosaccharides, disaccharides, and polysaccharides is crucial for categorizing these biological molecules correctly.

Q65. Which of the following blood vessels have lowest blood velocity with correct reason for low blood velocity?

• A. Arteries: Due to thick walls
• B. Capillaries: due to highest overall cross-sectional area✓
• C. Veins: due to blood flow against the gravity
• D. Capillaries: Due to two-way blood flow in capillaries

Explanation: The correct answer is B: Capillaries have the lowest blood velocity because they have the highest overall cross-sectional area, which significantly reduces the velocity of blood flow. This is essential for efficient exchange of oxygen, nutrients, and waste products with tissues. Option A is incorrect because, while arteries have thick walls, this does not correlate with low blood velocity; they actually transport blood away from the heart at a higher speed. Option C is misleading as veins do have a slower flow compared to arteries, but they do not possess the lowest velocity overall. Lastly, Option D is incorrect because capillaries are responsible for a single direction of blood flow, and the reasoning provided does not explain their low velocity correctly.

Q66. Olfactory receptors are the type of:

• A. Photoreceptors
• B. Mechanoreceptors
• C. Thermoreceptors
• D. Chemoreceptors✓

Explanation: Olfactory receptors are classified as chemoreceptors because they detect chemical substances in the air. When these chemicals bind to the olfactory receptors in the nasal cavity, they initiate a signal that is interpreted by the brain as smell. The other options, such as photoreceptors, mechanoreceptors, and thermoreceptors, are specialized for different sensory modalities—vision, touch, and temperature, respectively—and do not relate to the olfactory system.

Q67. An active athlete has more stamina of running compared to an officer of same age with physically inactive lifestyle. Which of the following organelles has greatly increased in the muscle cells of athlete?

• A. Nucleus
• B. Mitochondria✓
• C. Golgi bodies
• D. Smooth endoplasmic reticulum (SER)

Explanation: The correct answer is Mitochondria because they are crucial for aerobic respiration and energy production in cells. Active athletes have a higher demand for energy during physical activities, which leads to an increase in the number and efficiency of mitochondria in their muscle cells. This adaptation enables them to sustain prolonged physical exertion. The other options are incorrect because:Nucleus: While essential for cell function, it does not increase in response to physical activity.Golgi bodies: These are involved in protein processing and do not directly affect energy levels.Smooth endoplasmic reticulum (SER): This organelle is more related to lipid metabolism and detoxification than energy production.

Q68. Which of the following organisms eliminate nitrogenous waste mainly in the form of uric acid?

• A. Freshwater Fish
• B. Amphibians
• C. Birds✓
• D. Mammals

Explanation: Birds are unique among the options given because they excrete nitrogenous waste primarily in the form of uric acid. This adaptation allows them to conserve water, which is particularly advantageous for their survival in various habitats. Freshwater fish excrete ammonia due to the abundance of water, while amphibians and mammals primarily excrete urea, which is less toxic than ammonia but still requires more water for excretion. Therefore, while all options represent different strategies of nitrogenous waste elimination, only birds utilize uric acid as their main waste product.

Q69. Once an action potential reaches the membrane of a skeletal muscle fiber, what is the first event that occurs in the contraction process?

• A. Actin and myosin form a cross-bridge
• B. Calcium is pumped back into the sarcoplasmic reticulum
• C. Calcium is released from the sarcoplasmic reticulum✓
• D. ATP is hydrolyzed by troponin

Explanation: When an action potential reaches the skeletal muscle fiber membrane, it triggers the release of calcium ions from the sarcoplasmic reticulum. This release is the first critical step in the contraction process, as calcium ions bind to troponin, allowing the actin and myosin filaments to interact and initiate contraction. Option A is incorrect because the cross-bridge formation between actin and myosin occurs after calcium is released and has bound to troponin. Option B is also incorrect as it describes a process that occurs during muscle relaxation. Option D is misleading because ATP is not hydrolyzed by troponin; instead, ATP hydrolysis occurs within the myosin head to provide energy for muscle contraction.

Q70. Which of the following cells possess Nissl's granules?

• A. Nerve cells✓
• B. WBC
• C. RBC
• D. Platelets

Explanation: The correct answer is nerve cells, as they contain Nissl's granules, which are indicative of their active role in protein synthesis necessary for neurotransmitter production and overall cellular function. In contrast, white blood cells (WBCs), red blood cells (RBCs), and platelets do not contain these granules. WBCs are part of the immune system, RBCs are mainly for oxygen transport and lack organelles entirely, and platelets are involved in blood clotting but are not true cells, lacking nuclei and organelles found in nerve cells.

Q71. Which part of human brain is involved in maintaining the posture and balance of the body?

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

Explanation: The correct answer is the Cerebellum. This part of the brain is specifically involved in the coordination of voluntary movements, balance, and maintaining posture. It receives input from the sensory systems and other parts of the brain and spinal cord, allowing it to fine-tune motor activities. The Cerebrum, while important for many functions including movement and sensory processing, does not directly manage balance. The Hypothalamus is involved in controlling bodily functions like temperature, hunger, and thirst, but is not responsible for motor control. Lastly, the Medulla oblongata manages autonomic functions but does not directly influence posture and balance.

Q72. Arthritis is:

• A. Inflammation of joints✓
• B. Infection of intervertebral disc
• C. Fusion of vertebral joint
• D. Tingling along the length of legs

Explanation: Arthritis is primarily characterized by inflammation of the joints, leading to pain, swelling, stiffness, and decreased range of motion. This makes Option A the correct answer. The other options describe different medical conditions: Option B refers to an infection of the intervertebral disc, which can cause back pain but is not arthritis. Option C describes a condition where vertebral joints may fuse, which is not the definition of arthritis. Finally, Option D mentions tingling sensations, which are usually indicative of nerve issues rather than joint inflammation.

Q73. Which type of joint is present in pubis?

• A. Fibrous joints
• B. Immoveable joints
• C. Cartilaginous joints✓
• D. Freely moveable joints

Explanation: The correct answer is Cartilaginous joints because the pubic symphysis, which is the joint connecting the left and right pubic bones, is classified as a cartilaginous joint. This type of joint allows for slight movement and provides some flexibility, especially important during childbirth. In contrast, fibrous joints do not permit movement and are fixed, as seen in skull sutures. Immoveable joints also do not allow any movement, which does not apply to the pubis as it allows for limited mobility. Lastly, freely moveable joints allow for a wide range of motion but are not applicable to the pubis, which is primarily designed for stability and limited movement.

Q74. Which type of neurons stimulate muscles to contract in a reflex arc?

• A. Motor neurons✓
• B. Sensory neurons
• C. Interneurons
• D. Relay neurons

Explanation: The correct answer is Motor neurons because they are specifically responsible for carrying impulses from the central nervous system to skeletal muscles, leading to muscle contraction in response to a reflex action. In a reflex arc, a stimulus activates sensory neurons, which send signals to interneurons in the spinal cord. The interneurons then relay the signal to motor neurons, which ultimately stimulate the muscles to contract. Sensory neurons (Option B) are involved in transmitting sensory information but do not cause muscle contraction. Interneurons (Option C) serve as connectors within the central nervous system and do not directly affect muscle activity. Relay neurons (Option D) are often synonymous with interneurons and also do not stimulate muscle contractions directly.

Q75. Reversible inhibitors differ from irreversible inhibitors because they:

• A. Binds permanently and cannot be removed
• B. Bind temporarily and can be removed✓
• C. Permanently inactivate the enzyme
• D. Change enzyme structure permanently

Explanation: Reversible inhibitors interact with enzymes through non-covalent interactions such as hydrogen bonds, ionic interactions, or hydrophobic interactions. This allows them to bind temporarily and be removed, restoring the enzyme's activity. In contrast, irreversible inhibitors form permanent bonds with the enzyme, leading to lasting inactivation. Therefore, option B is the correct answer as it accurately describes the nature of reversible inhibitors. Options A, C, and D incorrectly describe the characteristics of irreversible inhibitors, which permanently bind to and alter the enzyme's structure.

Q76. Why are retroviruses placed in a separate class of RNA viruses?

• A. They always infect animal cells only
• B. Their RNA acts directly as mRNA
• C. They lack protein coats
• D. They use reverse transcriptase to make DNA from RNA✓

Explanation: Retroviruses are classified separately from other RNA viruses primarily due to their unique replication mechanism that involves reverse transcriptase. This enzyme allows retroviruses to synthesize DNA from their RNA, which can then integrate into the host's genome. This process is distinct from most RNA viruses, which do not reverse transcribe their RNA into DNA. The other options present common misconceptions: A) Retroviruses do infect animal cells, but this is not the defining feature for their classification; B) While some RNA viruses act directly as mRNA, retroviruses must first convert their RNA into DNA; C) Retroviruses do have protein coats, contrary to the claim that they lack them.

Q77. Peptide bonds are Important in protein because they:

• A. Affect solubility
• B. Hold R-groups
• C. Link amino acid✓
• D. Help in releasing oxygen

Explanation: Peptide bonds are essential because they link amino acids together, forming polypeptides and ultimately proteins. This covalent bond is created through a condensation reaction, where a molecule of water is released. The other options are incorrect because:Option A: Peptide bonds do not directly affect the solubility of proteins; solubility is influenced by various factors, including the protein's overall structure and the environment it is in.Option B: While R-groups contribute to the overall structure and function of proteins, they are not directly held together by peptide bonds, which only link the amino acids.Option D: The release of oxygen is not a function of peptide bonds; rather, it pertains to proteins like hemoglobin that bind oxygen through different mechanisms.

Q78. Which is an enzyme activator secreted by the intestinal glands:

• A. Amylase
• B. Pepsinogens
• C. Enterokinase✓
• D. Lipase

Explanation: The correct answer is Enterokinase, as it is specifically secreted by the intestinal glands and acts as an enzyme activator, converting trypsinogen into trypsin. This activation is crucial for the digestion of proteins in the small intestine. In contrast, Amylase and Lipase are enzymes involved in carbohydrate and fat digestion, respectively, but they do not act as activators and are secreted by other organs. Pepsinogens, while important for protein digestion, are secreted in the stomach and are not relevant to this question regarding intestinal gland secretion.

Q79. According to Lock and Key model, the active site is regarded as:

• A. Rigid and specific✓
• B. Flexible and specific
• C. Rigid and non specific
• D. Flexible and non specific

Explanation: The Lock and Key model of enzyme action posits that the active site of an enzyme is a rigid structure that only fits specific substrates, akin to a key fitting into a lock. This model emphasizes the specificity of enzyme-substrate interactions, suggesting that each enzyme will only catalyze reactions for particular substrates that match its active site's shape. Option A is correct because it accurately describes this concept as 'Rigid and specific.' Options B, C, and D are incorrect; Option B mixes concepts from the Induced Fit model, while Options C and D misinterpret the specificity required for enzyme action outlined by the Lock and Key model.

Q80. Which of the following statements best compares cell division in prokaryotic and Eukaryotic cells?

• A. Eukaryotes divide by budding; prokaryotes by mitosis
• B. Eukaryotes use binary fission; prokaryotes by meiosis
• C. Eukaryotes divide by mitosis; prokaryotes by binary fission✓
• D. Both use mitosis for cell division

Explanation: The correct answer is that eukaryotic cells divide by mitosis while prokaryotic cells divide by binary fission. Mitosis is a complex process involving multiple stages (prophase, metaphase, anaphase, telophase) that allows for equal distribution of chromosomes in eukaryotic cells. In contrast, binary fission is a simpler and faster process in prokaryotic cells, where the cell grows and splits into two identical daughter cells without the intricate stages found in mitosis. The other options misrepresent the methods of cell division: budding is not a common method for eukaryotic cell division, meiosis is specific to gamete formation in eukaryotes, and the statement that both types use mitosis is entirely inaccurate for prokaryotes.

Q81. In which of the following combination, both components have Hyaline cartilage?

• A. Epiglottis & intervertebral disc
• B. Trachea & intervertebral disc
• C. Nose & pinna
• D. Nose & trachea✓

Explanation: The correct answer is Nose & trachea because both structures are supported by hyaline cartilage, which is known for its smooth, glassy appearance and is crucial in providing support and maintaining the shape of these structures. The nose's cartilage aids in maintaining its shape, while the trachea's hyaline cartilage rings prevent it from collapsing during breathing. The other options are incorrect due to the presence of different types of cartilage: the epiglottis is made of elastic cartilage, the intervertebral disc consists predominantly of fibrocartilage, and the pinna is also primarily elastic cartilage. Thus, they do not meet the criteria of being composed entirely of hyaline cartilage.

Q82. Which of the following best describes "acquired characteristics" according to Lamarckism?

• A. Traits caused by mutation
• B. Traits inherited from parents
• C. Traits acquired by use or disuse✓
• D. Traits selected by nature

Explanation: Lamarckism posits that organisms can pass on traits they acquire during their lifetime to their offspring. This means that if an organism develops a characteristic through use (like stronger muscles from exercise) or loses a characteristic through disuse (like a bird losing its ability to fly), these traits can be inherited by the next generation. Option C correctly represents this idea. Option A is incorrect because traits caused by mutation are random genetic changes, not acquired characteristics. Option B is also incorrect as it refers to genetic inheritance from parents, which is not a concept in Lamarckism. Option D is incorrect because it refers to natural selection, a concept associated with Darwin's theory of evolution, not Lamarck's.

Q83. Which of the following muscle types are involuntary in action?

• A. Skeletal and smooth
• B. Skeletal and cardiac
• C. Cardiac and smooth✓
• D. Smooth muscle only

Explanation: The correct answer is Cardiac and smooth (Option C). Both of these muscle types operate involuntarily, meaning they function without conscious control. Cardiac muscle is specialized to make up the heart, allowing it to pump blood autonomously. Smooth muscle, found in various internal organs such as the intestines and blood vessels, also operates without voluntary control.In contrast, skeletal muscle (found attached to bones) is under voluntary control, which means it is consciously manipulated by the nervous system. Thus, Options A and B are incorrect as they include skeletal muscle. Option D, while correct about smooth muscle being involuntary, is incomplete as it does not acknowledge cardiac muscle's involuntary nature.

Q84. Which of the following characters is shared by both skeletal and cardiac muscles?

• A. Presence of Striation✓
• B. Involuntary control
• C. Multinucleated fibers
• D. Intercalated discs

Explanation: The correct answer is the presence of striation, as both skeletal and cardiac muscles exhibit this characteristic. Striations are a result of the organized arrangement of actin and myosin filaments within the muscle cells, which is common for both muscle types. In contrast, involuntary control is a characteristic of cardiac muscle only, while skeletal muscle is controlled voluntarily. The multinucleated fibers option is incorrect because skeletal muscle fibers contain multiple nuclei, while cardiac muscle typically has one or two. Lastly, intercalated discs are specific to cardiac muscle cells, allowing for synchronized contraction, and are not found in skeletal muscle cells.

Q85. The main role of mRNA during protein synthesis is to:

• A. Carry genetic information for protein synthesis✓
• B. stabilize ribosome
• C. deliver amino acids
• D. provide platform for proteins synthesis

Explanation: The correct answer is Option A: Carry genetic information for protein synthesis. mRNA (messenger RNA) is synthesized during transcription and carries the genetic code from DNA to the ribosome, where proteins are synthesized. This process is crucial because the sequence of nucleotides in the mRNA dictates the sequence of amino acids in the resulting protein, thus directly linking genetic information to protein formation.Option B is incorrect because stabilizing the ribosome is primarily the role of rRNA, not mRNA. Option C is incorrect as tRNA is responsible for the delivery of amino acids to the ribosome, not mRNA. Finally, Option D is inaccurate because while the ribosome serves as the platform for protein synthesis, mRNA's role is to provide the instructions for what to synthesize, not to act as the platform itself.

Q86. Which layer of uterus nourishes the embryo after implantation?

• A. Cervical epithelium
• B. Myometrium
• C. Endometrium✓
• D. Perimetrium

Explanation: The correct answer is the endometrium, which is the inner lining of the uterus that plays a vital role in supporting embryonic development after implantation. It provides essential nutrients and a suitable environment for the embryo to thrive. In contrast, the cervical epithelium is not involved in nourishment but rather acts as a barrier. The myometrium is primarily responsible for uterine contractions and does not contribute to nourishing the embryo. Lastly, the perimetrium serves as a protective outer layer and does not participate in the nourishment process.

Q87. If a normal person marries with colour blind female what will be the possibility of normal male child:

• A. 0%✓
• B. 25%
• C. 50%
• D. 75%

Explanation: In this scenario, the mother is color blind, which means she carries two X chromosomes with the allele for color blindness (XcXc). The father is normal, meaning he has one normal X chromosome (X) and one Y chromosome (Y). When they have children, the mother can only provide Xc to her offspring. Therefore, all male children (who inherit the Y chromosome from their father) will receive Xc from their mother, resulting in 100% of male offspring being color blind. This leads to the conclusion that the possibility of a normal male child is 0%. The other options (25%, 50%, 75%) incorrectly suggest that there is a chance for normal male offspring, which is not supported by the genetics of color blindness inheritance.

Q88. A student observed a boundary in both plant and animal cells that controls entry and exit of substances. Which of the following structures is likely being observed?

• A. Mitochondria
• B. Golgi apparatus
• C. Plasma membrane✓
• D. Cell wall

Explanation: The correct answer is Plasma membrane because it is the structure that forms the boundary of both plant and animal cells, controlling the movement of substances in and out of the cell. The plasma membrane is selectively permeable, meaning it allows certain substances to pass while blocking others.In contrast, Mitochondria are organelles responsible for energy production and do not serve as a barrier. The Golgi apparatus is involved in processing and packaging proteins and lipids, but it does not regulate substance entry or exit. Lastly, the Cell wall provides structural support in plant cells but does not function as a selective barrier like the plasma membrane.

Q89. According to Lamarck, the evolution of lon necks in giraffes is explained by:

• A. Natural selection
• B. Genetic mutation
• C. Survival of the fittest
• D. Stretching of necks over generations✓

Explanation: Lamarck proposed that evolutionary changes occur through the use and disuse of traits, leading to the idea that giraffes developed long necks by stretching to reach food high in trees, and this acquired characteristic was then inherited by their offspring. This concept is known as inheritance of acquired characteristics. In contrast, the other options are rooted in Darwinian principles: natural selection and survival of the fittest involve environmental pressures selecting for traits that already exist, rather than the direct acquisition of traits through use. Genetic mutation is a modern understanding of variation, which Lamarck's theory does not incorporate.

Q90. The process of spermatogenesis occurs in which part of the male reproductive system?

• A. Seminiferous tubules✓
• B. Vas deferens
• C. Scrotum
• D. Epididymis

Explanation: Spermatogenesis is the process of sperm cell development, which occurs specifically in the seminiferous tubules located within the testes. These tubules provide the necessary environment and support for the formation of sperm from precursor cells. The vas deferens, scrotum, and epididymis, while important structures in the male reproductive system, do not participate in the actual production of sperm. The vas deferens is involved in transporting sperm, the scrotum helps regulate temperature, and the epididymis is where sperm mature post-production.

Q91. Glycoproteins are formed as a result of the combination of:

• A. Lipids and proteins
• B. Carbohydrates and proteins✓
• C. Nucleic acid and proteins
• D. Fatty acids and carbohydrates

Explanation: Glycoproteins are biomolecules formed from the combination of carbohydrates and proteins through a process called glycosylation. They are crucial for various biological functions, including cell-cell recognition, signaling, and immune responses. The correct answer is Option B, as it directly identifies the two components involved in the formation of glycoproteins. Option A is incorrect because lipids are not a part of glycoprotein structure. Option C involves nucleic acids, which have distinct roles in genetic information storage and transmission, not glycoprotein formation. Option D is also incorrect as it suggests a combination that does not occur in glycoprotein synthesis.

Q92. In which of the following combinations, both components have non-striated muscle fibers?

• A. Intestine & biceps
• B. Intestine & blood vessels✓
• C. Heart & lungs
• D. Stomach & heart

Explanation: The correct answer is Option B: Intestine & blood vessels. Both the intestine and blood vessels are composed of non-striated muscle fibers, which are smooth muscles responsible for involuntary movements. In contrast, the biceps (Option A) are composed of striated muscle fibers, which are voluntary. Option C includes the heart, which is made of striated muscle fibers, and the lungs that contain smooth muscle, making it incorrect. Similarly, Option D includes the heart as well, which again has striated muscle fibers, thus making it incorrect as well.

Q93. Pick the order of ease of reduction of H+1,Cu+2 and Ag+1

• A. H+1 > Ag+1 > Cu+2
• B. Ag+1 > Cu+2 > H+1✓
• C. Ag+1 > H+1 > Cu+2
• D. H+1 > Cu+2 > Ag+1

Explanation: The correct answer is Option B: Ag+1 > Cu+2 > H+1. This order reflects the standard reduction potentials where Ag+1 has the highest potential, making it the easiest to reduce, followed by Cu+2, and finally H+1 which has the lowest potential among these ions. Options A, C, and D incorrectly place H+1 in relation to Ag+1 and Cu+2, failing to align with their respective standard reduction potentials.

Q94. Acetaldehyde undergoes oxidation to produce acetic acid, In this reaction oxidizing agent used is

• A. LiAlH4
• B. K2Cr2O7✓
• C. LiNH2
• D. NaBH4

Explanation: In the oxidation of acetaldehyde to acetic acid, K2Cr2O7 acts as the oxidizing agent. This compound's strong oxidizing properties allow it to effectively oxidize aldehydes to carboxylic acids. In contrast, LiAlH4 and NaBH4 are both strong reducing agents used to reduce carbonyl compounds rather than oxidize them. LiNH2 is not an oxidizing agent; it serves mainly as a base and nucleophile. Therefore, among the provided options, K2Cr2O7 is the only appropriate choice for this oxidation reaction.

Q95. Which one of the following has higher vapour pressure?

• A. Acetone
• B. Acetaldehyde
• C. Isopentane✓
• D. Benzene

Explanation: Isopentane has the highest vapor pressure among the options due to its non-polar nature and weaker intermolecular forces (London dispersion forces), which allow more molecules to escape into the vapor phase. In contrast, acetone and acetaldehyde, being polar, have stronger dipole-dipole interactions that lower their vapor pressures. Benzene, although non-polar, has a more compact structure and stronger intermolecular forces than isopentane, resulting in a lower vapor pressure than isopentane but higher than that of acetone and acetaldehyde.

Q96. Terminal alkynes show acidic character due to:

• A. Terminal carbon atoms are $ ext{sp}^3$ hybridized
• B. Terminal carbon atoms are $ ext{sp}$ hybridized✓
• C. Terminal carbon atoms are $ ext{sp}^2$ hybridized
• D. Terminal carbon atoms show hydrogen bonding.

Explanation: Terminal alkynes exhibit acidic character primarily because the carbon atoms involved in the terminal position of the triple bond are $ ext{sp}$ hybridized. This hybridization leads to a higher s-character (50%), which stabilizes the negative charge of the conjugate base formed when the acidic hydrogen is removed. Therefore, terminal alkynes can release a proton (H+) more readily than alkenes or alkanes. In contrast, $ ext{sp}^3$ hybridized carbons (as in alkanes) do not exhibit acidity, and $ ext{sp}^2$ hybridized carbons (as in alkenes) have a lower acidity compared to $ ext{sp}$ hybridized carbons. The statement about hydrogen bonding does not pertain to acidity directly; it pertains more to intermolecular interactions.

Q97. Shape of orbital is determined by quantum number:

• A. n
• B. l✓
• C. m
• D. s

Explanation: The correct answer is l, which is the azimuthal quantum number. It directly describes the shape of the orbital. For example, when l = 0, the orbital is spherical (s), when l = 1, it is dumbbell-shaped (p), and higher values of l correspond to more complex shapes (d and f orbitals). Option n is incorrect because it only indicates the energy level of the electron and does not convey any information about the shape of the orbital. Option m is also incorrect as it pertains to the orientation of the orbital rather than its shape. Lastly, option s is misleading; while it refers to a specific orbital type, it is not a quantum number and thus cannot determine the shape of an orbital.

Q98. The theories which explain the formation of sigma and pi bond are EXCEPT:

• A. MOT
• B. VBT
• C. VSEPR
• D. CFT✓

Explanation: The correct answer is CFT (Crystal Field Theory) because it focuses on the interaction of transition metal ions with surrounding ligands and does not provide a mechanism for the formation of sigma and pi bonds. In contrast, both MOT (Molecular Orbital Theory) and VBT (Valence Bond Theory) are applicable theories that explain how these types of bonds are formed through orbital interactions. VSEPR (Valence Shell Electron Pair Repulsion) theory, while useful for predicting molecular shape, does not deal with the bonding mechanisms directly. Therefore, CFT is the only theory listed that does not explain sigma and pi bond formation.Although Both Option C and Option D is correct according to our textbook, but in Ofiicial UHS MDCAT 2025 key, this question has Option D as correct answer, so we will follow the official to ensure the key alingment and authenticity

Q99. The value of Planck's constant is:

• A. 6.6262 x 10-30 J.sec
• B. 6.6262 x 10-32 J.sec
• C. 6.6262 x 10+34 J.sec
• D. 6.6262 x 10-34 J.sec✓

Explanation: The correct value of Planck's constant is 6.6262 x 10-34 J.sec. This constant is pivotal in quantum mechanics, linking the energy of a photon to its frequency through the equation E = hf, where E is energy, h is Planck's constant, and f is frequency. The other options are incorrect as they either significantly understate or overstate the value of Planck's constant, indicating a lack of understanding of its correct scientific magnitude.

Q100. Final equation for the representation of rate of reaction in term of concentration is called

• A. Rate law✓
• B. Rate constant
• C. Reaction rate
• D. Reaction order

Explanation: The correct answer is Rate law, as it is the mathematical expression that relates the rate of a reaction to the concentrations of the reactants. It encompasses the order of the reaction and the rate constant, providing a comprehensive view of how the concentration affects the rate. The other options, while related to reaction kinetics, do not represent the final equation itself. The rate constant is a factor in the rate law, the reaction rate is the outcome derived from the law, and reaction order is an aspect of the rate law that indicates how the rate depends on the concentration, but it is not the complete equation.

Q101. Poly vinyl chloride (PVC) is the type of?

• A. Homopolymer
• B. Thermosetting polymer
• C. Thermoplastic polymer✓
• D. Copolymer

Explanation: Poly vinyl chloride (PVC) is a widely used thermoplastic polymer made from the polymerization of vinyl chloride monomers. As a thermoplastic, it can be softened upon heating and reshaped, which differentiates it from thermosetting polymers that cannot be remolded after curing. Although PVC is a homopolymer since it consists of one type of monomer, the key characteristic being asked about in this question is its thermal behavior. Therefore, the correct answer is that PVC is a thermoplastic polymer. The other options are incorrect because they either misclassify PVC based on its composition (homopolymer and copolymer) or thermal properties (thermosetting polymer).Although Both Option A and Option C is correct according to our textbook, but in Ofiicial UHS MDCAT 2025 key, this question has Option C as correct answer, so we will follow the official to ensure the key alingment and authenticity

Q102. Which of the following is true about pressure for an ideal gas at -273o C?

• A. P = 1 atm
• B. P = 2 atm
• C. P = 3 atm
• D. P = 0 atm✓

Explanation: The correct answer is P = 0 atm. According to the ideal gas law, as the temperature of a gas approaches absolute zero (-273°C), the kinetic energy of the gas particles also approaches zero. Since pressure is a measure of the force exerted by particles colliding with the walls of their container, no particle movement at absolute zero means no collisions and consequently no pressure. The other options (1 atm, 2 atm, and 3 atm) incorrectly assume that some pressure exists at this temperature, which contradicts the principles of gas behavior at absolute zero.

Q103. Which of the following is a basic buffer?

• A. NH4OH / NH4Cl✓
• B. NaOH / NaCl
• C. NaOH / HCl
• D. H2CO3 / NaHCO3

Explanation: The correct answer is NH4OH / NH4Cl, which forms a basic buffer because it consists of a weak base (ammonium hydroxide) and its conjugate acid (ammonium chloride). A buffer solution resists changes in pH upon the addition of small amounts of acid or base. In contrast, the other options do not satisfy the criteria for a basic buffer: NaOH / NaCl contains a strong base and a neutral salt, thus lacking the necessary weak base.NaOH / HCl is a strong base and a strong acid, which result in complete neutralization and no buffering capacity.H2CO3 / NaHCO3 forms an acidic buffer, not a basic one, as it is based on a weak acid and its salt.

Q104. What happens when H+ is added to ammonium hydroxide and ammonium chloride buffer?

• A. More ammonium hydroxide is formed
• B. The reaction will move reverse
• C. The reaction will move forward✓
• D. No effect on equilibrium

Explanation: When H+ ions are added to the ammonium hydroxide (NH4OH) and ammonium chloride (NH4Cl) buffer system, the increased concentration of H+ ions leads to a shift in the equilibrium of the reaction. The buffer system consists of the weak base (NH4OH) and its conjugate acid (NH4Cl), and when H+ is added, it reacts with NH4OH to produce more NH4+ ions. This results in the forward shift of the equilibrium to neutralize the added acid. Therefore, the correct answer is that the reaction will move forward. The other options are incorrect as they misinterpret the behavior of the buffer system in response to changes in pH.

Q105. What is general requirement for free radical substitution reaction of ethane and halogen?

• A. Low pressure
• B. Low temperature
• C. High pressure
• D. Heat and UV light✓

Explanation: The correct answer is Heat and UV light because free radical substitution reactions, such as those involving ethane and halogens, require sufficient energy to break the halogen bond and generate free radicals. This can be achieved through heating or by exposure to UV light, which facilitates the initiation step of the reaction. In contrast, the other options (Low pressure, Low temperature, and High pressure) do not provide the necessary energy for the reaction to proceed effectively. Low pressure and temperature would hinder the reaction, while high pressure, although it might increase reactant concentration, is not a specific requirement for free radical substitution.

Q106. Which one of the following is not a characteristic of benzene?

• A. Aromaticity
• B. Stability
• C. to follow Huckle rule
• D. High reactivity✓

Explanation: The correct answer is High reactivity. Benzene is characterized by its stability and aromatic nature, which make it less reactive compared to many other hydrocarbons. It undergoes electrophilic substitution rather than addition reactions, which is a hallmark of its stability. In contrast, the other options are true characteristics of benzene: Aromaticity is a defining feature, indicating its unique electron configuration; Stability refers to its resistance to reactions typical of alkenes; and Hückel's rule confirms its aromatic nature based on the count of π-electrons.

Q107. Correct arrangement of orbital according to size of hybridized orbitals

• A. sp > sp2 > sp3
• B. sp2 > sp > sp3
• C. sp3 > sp2 > sp✓
• D. sp3 > sp > sp2

Explanation: The correct answer is Option C: sp3 > sp2 > sp. This order reflects the relationship between the s-character of the hybridized orbitals and their size. As the s-character increases (from sp to sp2 to sp3), the size of the orbitals increases. Therefore, sp3 orbitals, which have 25% s-character and 75% p-character, are the largest, followed by sp2 (33% s-character) and finally sp (50% s-character), which is the smallest. Options A, B, and D present incorrect relationships in the sizes of the hybridized orbitals.

Q108. Consider the equation H2 + O2 --> H2O, what volume of hydrogen gas is required to produce 1 mol of water at standard temperature & pressure?

• A. 11.2 dm3
• B. 22.4 dm3✓
• C. 18 dm3
• D. 58 dm3

Explanation: The balanced chemical equation for the reaction is: 2 H2 + O2 → 2 H2O. From this equation, we see that 2 moles of hydrogen gas are needed to produce 2 moles of water. Therefore, to produce 1 mole of water, we need 1 mole of hydrogen gas. At standard temperature and pressure (STP), 1 mole of any gas occupies 22.4 liters (or dm3). Thus, the correct answer is 22.4 dm3 (Option B).Option A (11.2 dm3) is incorrect because it represents only half a mole of hydrogen gas, which is insufficient to produce 1 mole of water. Option C (18 dm3) does not correspond to a whole number of moles of hydrogen required; thus, it is also incorrect. Lastly, Option D (58 dm3) is excessive, as it exceeds the stoichiometric requirement for producing 1 mole of water.

Q109. A chemical reaction has a theoretical yield of 25g, but only 20g of product was obtained. What is the percentage yield of the reaction?

• A. 20%
• B. 25%
• C. 45%
• D. 80%✓

Explanation: To calculate the percentage yield, you use the formula: Percentage Yield = (Actual Yield / Theoretical Yield) x 100. In this case, you have an actual yield of 20g and a theoretical yield of 25g. Therefore, Percentage Yield = (20g / 25g) x 100 = 80%. This means that the reaction produced 80% of the expected product. The other options are incorrect because they do not correctly apply the yield formula or misinterpret the relationship between actual and theoretical yields.

Q110. Which of the following situations most clearly demonstrates a key characteristic of a Redox reaction?

• A. Water boiling to steam
• B. Hydrogen gas reacting with chlorine to form hydrogen chloride gas✓
• C. Sodium chloride dissolving in water
• D. Ethanol evaporating at room temperature

Explanation: The correct answer is Option B: Hydrogen gas reacting with chlorine to form hydrogen chloride gas. This is a classic Redox reaction where hydrogen (H2) is oxidized (loses electrons) and chlorine (Cl2) is reduced (gains electrons), resulting in the formation of hydrogen chloride (HCl). This reaction clearly illustrates the transfer of electrons, a key characteristic of Redox processes.Options A, C, and D do not involve any changes in oxidation states or electron transfer. Option A describes a physical change (boiling), while Options C and D involve dissolving and evaporating, respectively, which are also physical processes without any Redox characteristics.

Q111. Number of unpaired electrons in Boron in ground state is/are:

• A. 1✓
• B. 2
• C. 3
• D. 4

Explanation: Boron, with the atomic number 5, has an electronic configuration of 1s2 2s2 2p1. In this configuration, the first two electrons fill the 1s and 2s subshells completely, while the third electron occupies the 2p subshell. Since the 2p subshell can hold a maximum of six electrons, the single electron in the 2p subshell is unpaired. Therefore, Boron has one unpaired electron in its ground state. Options B (2), C (3), and D (4) are incorrect because they miscount the number of unpaired electrons based on Boron's actual electronic configuration.

Q112. Chlorination of benzene in the presence of iron (III) chloride involves mechanism of:

• A. Electrophilic addition
• B. Electrophilic Substitution✓
• C. Free radical Substitution
• D. Free radical halogenation

Explanation: The correct answer is Electrophilic Substitution because the chlorination of benzene involves the substitution of a hydrogen atom by a chlorine atom in the presence of an electrophile generated from chlorine and iron (III) chloride. This allows the aromatic ring to maintain its stability and aromatic characteristics. In contrast, Electrophilic addition is incorrect because it pertains to the addition of electrophiles to unsaturated hydrocarbons, which disrupts aromaticity. Free radical Substitution and Free radical halogenation are also incorrect as they apply to aliphatic compounds where radical mechanisms replace hydrogen atoms, not suitable for the stable benzene framework.

Q113. If 100 kJ of heat is absorbed by the system and 40 kJ of work is done on the system what is the change of internal energy?

• A. -60 kJ
• B. +60 kJ
• C. -140 kJ
• D. +140 kJ✓

Explanation: To find the change in internal energy (ΔU), we can use the formula: ΔU = Q + W, where Q is the heat added to the system and W is the work done on the system. Here, Q = +100 kJ (since heat is absorbed) and W = +40 kJ (since work is done on the system). So, ΔU = 100 kJ + 40 kJ = +140 kJ. This means the internal energy of the system increases by 140 kJ.Now, let's consider the incorrect options:-60 kJ: This implies that the system lost energy, which contradicts the positive contributions from heat and work.+60 kJ: This underestimates the total contribution, as it fails to account for the full amount of work done on the system.-140 kJ: This suggests a drastic energy loss, which is not supported by the positive values of heat and work provided.Thus, the correct answer is +140 kJ.

Q114. The element with smallest value of Ionization energy is

• A. Li
• B. Al
• C. Ca
• D. Ba✓

Explanation: The correct answer is Ba (Barium) because it has the smallest ionization energy due to its position in the periodic table. As you move down a group, the ionization energy decreases because the outermost electrons are further from the nucleus and are thus less tightly held, making them easier to remove. In contrast, Li (Lithium) has a high ionization energy as it is at the top of Group 1; Al (Aluminum) has a moderate ionization energy, higher than barium; and Ca (Calcium) has a lower ionization energy than aluminum but still higher than that of barium due to being higher in the group. Therefore, the trend of decreasing ionization energy down the group clearly shows that barium has the lowest value among the options presented.

Q115. Carboxylic acid reacts with ammonia to form ammonium salts which on heating produces

• A. Carbonates
• B. Alkane
• C. Ester
• D. Amide✓

Explanation: When carboxylic acids react with ammonia, they form ammonium salts. Upon heating these salts, a dehydration reaction occurs, leading to the formation of amides. Amides are characterized by the presence of the CONH₂ group and are derived from the carboxylic acid functional group. The other options are incorrect because:Carbonates: These are not related to the reaction of carboxylic acids and ammonia.Alkane: Alkanes do not result from this reaction; they are formed via different chemical pathways.Ester: Esters form from the reaction of carboxylic acids with alcohols, not with ammonia.

Q116. Number of unpaired electrons present in the ground state of Fe3+ (Atomic number of Fe=26):

• A. Three
• B. Four
• C. Five✓
• D. Six

Explanation: To determine the number of unpaired electrons in Fe3+, we start with the electron configuration of iron (Fe), which is [Ar] 4s2 3d6. When Fe loses three electrons to become Fe3+, the electrons are removed first from the 4s orbital and then from the 3d orbital. The resulting configuration for Fe3+ is [Ar] 3d5. In this configuration, all five 3d electrons are unpaired, resulting in a total of five unpaired electrons. Other options are incorrect because they do not accurately represent the number of unpaired electrons in the 3d subshell after ionization.

Q117. If % yield and actual yield is 80 and 20 g respectively, what will be theoretical yield?

• A. 20 g
• B. 25 g✓
• C. 30 g
• D. 40 g

Explanation: The theoretical yield can be calculated using the formula for percentage yield: % Yield = (Actual Yield / Theoretical Yield) × 100. Rearranging this formula to find the theoretical yield gives us:Theoretical Yield = Actual Yield / (% Yield / 100)Substituting the given values, we find:Theoretical Yield = 20 g / (80 / 100) = 20 g / 0.8 = 25 g.Thus, the theoretical yield is 25 g. Option A is incorrect as it assumes that actual yield equals theoretical yield. Option C is incorrect because it does not align with the calculated theoretical yield, and Option D overestimates the yield based on the actual yield provided.

Q118. Which of the following best identifies the redox reaction?

• A. transfer of proton
• B. transfer of electron✓
• C. absorption of light
• D. exchange of ions

Explanation: The correct answer is transfer of electron because redox reactions, short for reduction-oxidation reactions, are defined by the transfer of electrons between two species. In oxidation, a substance loses electrons, and in reduction, a substance gains electrons, resulting in a change in oxidation states. The other options do not accurately describe redox reactions: transfer of proton relates to acid-base chemistry; absorption of light pertains to photochemical processes; and exchange of ions does not specifically address the electron transfer that defines redox reactions.

Q119. Molecules having one lone pair and three bond pairs have geometrical shape

• A. Bent or angular
• B. Trigonal
• C. Trigonal pyramidal✓
• D. Trigonal planar

Explanation: The correct answer is Trigonal pyramidal. According to VSEPR theory, the presence of one lone pair and three bond pairs results in a pyramidal shape. The lone pair occupies more space and pushes down on the three bonding pairs, creating a three-dimensional shape that resembles a pyramid.The other options are incorrect as follows: Bent or angular is typically used for molecules with two bond pairs and one or more lone pairs, while Trigonal planar describes a structure with three bond pairs and no lone pairs. The option Trigonal is too vague and does not accurately describe the specific arrangement given in the question.

Q120. Conversion of dihaloalkane into alkyne does not involve

• A. Addition✓
• B. Elimination
• C. Base
• D. Heat

Explanation: The correct answer is Addition. The conversion of dihaloalkanes to alkynes is achieved through a series of elimination reactions where halide groups are removed, typically using a strong base, and often requires heat to facilitate the reaction. Addition reactions, on the other hand, involve adding new atoms or groups to a molecule and do not occur in this conversion process. The other options—Elimination, Base, and Heat—are all integral to the formation of alkynes from dihaloalkanes.

Q121. Majority of reactions taking place at ordinary temperatures with -deltaH are

• A. Endothermic
• B. Exothermic✓
• C. Thermally unstable
• D. Reversible

Explanation: The correct answer is B: Exothermic. Reactions that have a negative change in enthalpy (-deltaH) release energy, making them more likely to occur spontaneously at ordinary temperatures. This energy release can increase the disorder (entropy) of the system, further promoting spontaneity according to the second law of thermodynamics.Option A (Endothermic) is incorrect because endothermic reactions absorb energy, resulting in a positive change in enthalpy (+deltaH), which typically indicates non-spontaneity at ordinary conditions. Option C (Thermally unstable) is inaccurate as it refers to the stability of a substance rather than its enthalpy change or spontaneity. Option D (Reversible) is misleading; while some exothermic reactions can be reversible, the term does not inherently indicate spontaneity.

Q122. Which one of the following is a coinage metal

• A. Pd
• B. Cd
• C. Hg
• D. Cu✓

Explanation: The correct answer is Cu (Copper) because it is one of the traditional coinage metals, known for its high electrical and thermal conductivity, as well as its resistance to corrosion. Historically, copper has been used to make coins, which is why it is categorized as a coinage metal.The other options are incorrect for the following reasons:Pd (Palladium) is a precious metal, often used in catalytic converters and jewelry, but it is not used for minting coins.Cd (Cadmium) is a post-transition metal that is primarily used in batteries and is not suitable for coinage.Hg (Mercury) is a unique liquid metal at room temperature that has applications in thermometers and barometers, but it does not fall under the category of coinage metals.

Q123. Value of R gas constant in {J mol}^{-1} {K}^{-1} is

• A. 8.314✓
• B. 62.4
• C. 0.821
• D. 62400

Explanation: The correct value of the gas constant R is 8.314 J mol-1 K-1. This constant is crucial in the ideal gas law, which relates the pressure, volume, temperature, and number of moles of an ideal gas. The other options represent either incorrect values or units that do not correspond to the standard value of R in J mol-1 K-1. Option B (62.4) is sometimes used in an alternative context, but it is not the correct value for this question. Options C (0.821) and D (62400) do not represent valid values for the gas constant in any relevant unit system.

Q124. Which of the following best explains why phenol reacts with aqueous NaOH, but alcohols do not?

• A. Phenol has a lower boiling point than alcohol.
• B. Alcohols contain a strong OH bond that cannot be broken by weak bases.
• C. Phenol forms hydrogen bonding that facilitates ionization.
• D. Phenol is weakly acidic due to resonance stabilization of phenoxide ion.✓

Explanation: Phenol reacts with aqueous NaOH because it is a weak acid capable of donating a proton to form the phenoxide ion, which is stabilized by resonance. This property of phenol allows it to react with strong bases like NaOH. In contrast, alcohols lack significant acidity and do not ionize readily in the presence of bases, which explains their absence of reaction with NaOH. The incorrect options either focus on irrelevant factors like boiling points or bond strength or only partially address the role of hydrogen bonding without acknowledging acidity as the key factor in phenol's reactivity.

Q125. In propene pi-bond is formed by sideway overlap of

• A. s-orbitals
• B. p-orbitals✓
• C. sp3 hybrid orbitals
• D. sp2 hybrid orbitals

Explanation: In propene (C3H6), a double bond exists between the two carbon atoms, which consists of one sigma bond and one pi-bond. The pi-bond is formed by the sideways overlap of unhybridized p-orbitals from each of the two carbons. Option B, which identifies p-orbitals, is correct because they allow this type of overlap. Option A (s-orbitals) is incorrect because s-orbitals do not have the required orientation for sideways overlap. Option C (sp3 hybrid orbitals) is incorrect as they form sigma bonds but do not participate in pi-bond formation. Option D (sp2 hybrid orbitals) refers to the structure of the carbon atoms involved, which indeed have sp2 hybridization; however, the pi-bond itself arises from the p-orbitals, not the sp2 orbitals. Thus, while sp2 orbitals are relevant to the bonding framework, they do not directly form the pi-bond.

Q126. Oxidation numbers of X,Y,Z are +6, -2, & -1 respectively, possible molecular formula when atoms combine:

• A. XYZ2
• B. XY2Z
• C. XY2Z2✓
• D. XYZ

Explanation: The correct molecular formula is XY2Z2. In this formula, one atom of X with an oxidation state of +6 combines with two atoms of Y, each with a -2 oxidation state, and two atoms of Z, each with a -1 oxidation state. The total oxidation states are calculated as follows: (+6) + 2(-2) + 2(-1) = 6 - 4 - 2 = 0, meaning the compound is neutral. The other options do not yield a neutral charge based on the given oxidation states, making them incorrect.

Q127. An enzyme used to decompose the lipids into fatty acids in our alimentary canal is

• A. Amylase
• B. Protease
• C. Lipase✓
• D. Urease

Explanation: The correct answer is lipase, which is specifically responsible for breaking down lipids into fatty acids and glycerol in the digestive system. Lipase is secreted by the pancreas and plays a crucial role in the digestion and absorption of dietary fats.In contrast, amylase acts on carbohydrates, breaking them down into simple sugars, but does not affect lipids. Protease is focused on protein digestion, breaking proteins down into amino acids, while urease has a completely different function related to urea metabolism and does not interact with lipids at all. Therefore, only lipase is relevant to the question asked.

Q128. Methanol is produced by reduction of

• A. Formaldehyde✓
• B. Acetaldehyde
• C. Propanal
• D. Propanone

Explanation: Methanol is produced by the reduction of formaldehyde, which is an aldehyde. During the reduction process, the carbonyl group (C=O) of formaldehyde gains hydrogen, converting it into methanol (CH3OH). The other options do not lead to methanol upon reduction:Acetaldehyde would reduce to ethanol, not methanol.Propanal would reduce to propanol, which is also not methanol.Propanone (acetone) is a ketone and cannot be reduced to form methanol.Thus, the only correct answer is formaldehyde.

Q129. Consider the given balanced chemical equation: 2H2​+O2​→2H2​OIf 4 g of H₂ reacts with 32 g of O₂ to produce 28 g of H₂O, what is the percentage yield of the reaction?(Molar mass of H₂ = 2 g/mol, O₂ = 32 g/mol, and H₂O = 18 g/mol)

• A. 63%
• B. 77.8%✓
• C. 87.5%
• D. 92.5%

Explanation: To find the percentage yield, we first determine the theoretical yield using the balanced equation 2H₂ + O₂ → 2H₂O. From the equation, we see that 2 moles of H₂ react with 1 mole of O₂ to produce 2 moles of H₂O. Given the molar masses, 4 g of H₂ equates to 2 moles, and 32 g of O₂ equates to 1 mole. The limiting reagent is H₂ because it produces less water. The theoretical yield of H₂O is calculated as 2 moles H₂O × 18 g/mol = 36 g. The actual yield provided is 28 g. Therefore, the percentage yield is calculated as (actual yield/theoretical yield) × 100 = (28 g / 36 g) × 100 = 77.8%. This confirms that Option B is correct. The other options are incorrect because they either underestimate or overestimate the percentage yield based on the correct relationship between actual and theoretical yields.

Q130. The amount of energy needed to weaken the existing bonds to an extent that can be broken through collision is called:

• A. Bond energy
• B. Activation energy✓
• C. Average energy
• D. Enthalpy

Explanation: Activation energy is the energy barrier that must be overcome for a chemical reaction to take place. It is crucial in determining the rate at which a reaction occurs; a higher activation energy means that fewer molecules have sufficient energy to react at a given temperature. The other options do not accurately describe this concept: bond energy pertains to breaking specific bonds without reference to collision-based reactions, average energy does not focus on the energy needed for a reaction, and enthalpy is more about overall heat content rather than the specific energetic threshold required for bond breaking during a reaction.

Q131. For 2A + 2B → 3C, which of the following does not express the reaction rate?

• A. dC/dt
• B. -dB/dt
• C. -1/2dA/dt
• D. -1/3dC/dt✓

Explanation: The correct answer is -1/3dC/dt. This expression incorrectly represents the reaction rate, as it suggests that the rate of reaction is based on the rate of change of product C divided by 3, which does not align with the stoichiometry of the reaction. In this reaction, the rate of reaction should be based on the decrease in concentration of reactants or the increase in concentration of products without dividing by the stoichiometric coefficients of products in this manner.The other options are valid expressions of reaction rates:dC/dt: This expression indicates the rate of formation of product C.-dB/dt: This expression indicates the rate of consumption of reactant B.-1/2dA/dt: This expression indicates the rate of consumption of reactant A adjusted for its stoichiometric coefficient.Thus, options A, B, and C correctly express the reaction rate, while option D does not.

Q132. IUPAC name of(CH3)3CCH2Br is

• A. 1-bromopentane
• B. 1-bromo-2,2-trimethylethane
• C. 1-bromo-2,2-dimethylpropane✓
• D. 2-bromopentane

Explanation: The correct IUPAC name for (CH3)3CCH2Br is 1-bromo-2,2-dimethylpropane. To derive this name, first identify the longest continuous chain of carbon atoms, which in this case is the three-carbon propane backbone. The bromine is attached to the first carbon, while the two methyl groups are located on the second carbon. Thus, the correct structural representation leads to the name 1-bromo-2,2-dimethylpropane. The other options are incorrect due to misidentifying the longest chain or the positioning of the substituents.

Q133. Which one shows anisotropic behavior?

• A. Wood
• B. Gemstone
• C. Coke
• D. Graphite✓

Explanation: The correct answer is Graphite (Option D). Graphite is composed of layers of carbon atoms that can slide over each other, resulting in very different properties along the plane of the layers compared to perpendicular to them, which demonstrates anisotropic behavior.Option A, Wood, while showing some anisotropic characteristics, is not as pronounced as graphite. Option B, Gemstone, may have some anisotropic features depending on the specific type, but generally, they are more isotropic. Option C, Coke, behaves isotropically in most applications, lacking significant directional dependency.

Q134. In a unit cell of a crystal lattice the angle β is between faces:

• A. a and b
• B. b and c
• C. c and a✓
• D. not specified

Explanation: The correct answer is Option C: c and a. In crystallography, the angle β is specifically defined as the angle between the faces c and a of a unit cell. This measurement plays a crucial role in determining the overall symmetry and properties of the crystal structure. Options A and B are incorrect because they do not correspond to the correct faces that define angle β. Option D is also incorrect as it suggests that angle β is not specified, while in fact, it is a well-defined component of crystallographic parameters.

Q135. Pick the crystalline solid:

• A. Cement
• B. Ceramics
• C. Concrete
• D. Copper✓

Explanation: The correct answer is Copper, as it is a metallic element that forms a crystalline solid with a regular arrangement of atoms. In contrast, Cement and Concrete are primarily amorphous solids, lacking a defined geometric structure. Ceramics can vary but often do not possess the consistent crystalline nature of metals. Understanding the characteristics of crystalline versus non-crystalline solids is essential in identifying materials.

Q136. In a pipe of varying cross-section as fluid enters the narrower region, it exhibits:

• A. high velocity, high pressure
• B. high velocity, low pressure✓
• C. low velocity, high pressure
• D. low velocity, low pressure

Explanation: When fluid flows through a pipe with varying cross-sections, Bernoulli's principle applies. It states that in a streamline flow, an increase in the fluid's velocity leads to a decrease in pressure. Therefore, when the fluid enters a narrower region of the pipe, it must speed up (high velocity) and the pressure drops (low pressure). This is why the correct answer is Option B: high velocity, low pressure. The other options are incorrect because they contradict the fundamental principles of fluid dynamics as described by Bernoulli's equation.

Q137. The curved shape of an airplane wing causes air to move faster over the top surface. This leads to:

• A. greater pressure on the top
• B. lower pressure on the top✓
• C. equal pressure on both sides
• D. zero pressure above the wing

Explanation: The correct answer is Option B: lower pressure on the top. According to Bernoulli's principle, the curved shape of the airplane wing causes air to move faster over the top surface compared to the bottom surface. This increase in speed leads to a decrease in pressure above the wing, which is crucial for creating lift. Option A is incorrect because it states that there is greater pressure on the top; however, faster airflow results in lower pressure. Option C is incorrect because the pressure cannot be equal on both sides due to the differing speeds of the airflow. Option D is also incorrect as it implies that there is zero pressure above the wing, which is not true; there is reduced pressure, but it is not zero.

Q138. The protons in the nucleus of an atom DO NOT exit out due to

• A. Electromagnetic force
• B. Gravitational force
• C. Weak Nuclear Force
• D. Strong Nuclear Force✓

Explanation: The correct answer is Strong Nuclear Force. This force is responsible for overcoming the electromagnetic repulsion between the positively charged protons, effectively binding them together with neutrons within the atomic nucleus. Unlike the strong nuclear force, the electromagnetic force, gravitational force, and weak nuclear force do not provide the necessary attraction to keep protons from exiting the nucleus. The electromagnetic force would actually encourage protons to repel each other, while gravitational force is negligible at this scale, and the weak nuclear force does not contribute to the binding of nucleons.

Q139. Mechanical waves cannot travel through outer space because they:

• A. have low speed in vacuum
• B. disperse in space due to long wavelength
• C. lose frequency in the absence of air
• D. lose transmission without interacting particles✓

Explanation: The correct answer is D: lose transmission without interacting particles. Mechanical waves, including sound waves, rely on the presence of a medium (solid, liquid, or gas) to transmit energy through particle interactions. In outer space, the vacuum lacks these particles, meaning there is no medium for the wave to propagate. Option A is incorrect because it incorrectly relates the speed of mechanical waves to their inability to travel in a vacuum. The speed of sound is indeed zero in a vacuum, but this is because there is no medium to carry the sound, not because of a low speed. Option B is also incorrect, as dispersion due to long wavelength is not the reason mechanical waves can't travel in space; rather, it's the absence of particles. Option C misrepresents the relationship between frequency and the medium; frequency remains constant regardless of the medium's presence.

Q140. Terminal voltage of a cell equals its EMF only when:

• A. No current flows✓
• B. Current is maximum
• C. Internal resistance is infinite
• D. Load resistance is zero

Explanation: The terminal voltage of a cell is equal to its electromotive force (EMF) only when no current flows through the cell. This is because when no current is flowing, there is no voltage drop across the internal resistance of the cell, allowing the terminal voltage to equal the EMF directly.The other options are incorrect for the following reasons:Current is maximum: Maximum current would cause a significant voltage drop across the internal resistance, resulting in a terminal voltage lower than the EMF.Internal resistance is infinite: While this condition would prevent current from flowing, it is not a practical scenario that results in terminal voltage equaling EMF. The more relevant condition is having no current at all.Load resistance is zero: A zero load resistance would lead to maximum current draw, again causing a voltage drop across the internal resistance, resulting in terminal voltage being less than EMF.

Q141. If a loop moves toward a stationary magnet, the induced current will:

• A. enhance the motion
• B. try to stop the approach✓
• C. become zero
• D. become alternating

Explanation: According to Lenz's law, the induced current in a conductor will always flow in a direction that opposes the change in magnetic flux that produced it. In this case, as the loop moves toward the stationary magnet, the magnetic flux through the loop increases. To oppose this increase, the induced current will flow in a direction that creates a magnetic field opposing the motion, effectively trying to stop the loop's approach to the magnet. Thus, the correct answer is that the induced current will try to stop the approach.The other options are incorrect because:Enhance the motion: This contradicts Lenz's law, which states that the induced current opposes changes.Become zero: A current is induced due to the motion of the loop, so it cannot be zero.Become alternating: The current will not alternate unless the direction of motion changes, which is not the case here.

Q142. The energy of a Simple Harmonic oscillation depends upon the

• A. Frequency
• B. Time period
• C. Wavelength
• D. Amplitude✓

Explanation: The correct answer is Amplitude (Option D) because in Simple Harmonic Motion (SHM), the total mechanical energy is given by the formula: E = (1/2) k A², where k is the spring constant and A is the amplitude. This means that the energy depends on the square of the amplitude; hence, the greater the amplitude, the more energy the system possesses. Options A, B, and C are incorrect because: Frequency (Option A): While frequency affects the rate of oscillation, it does not directly affect the total energy of the system.Time period (Option B): Similar to frequency, the time period is inversely related to frequency and does not influence the energy of the oscillator.Wavelength (Option C): Wavelength pertains to wave phenomena, not directly to the energy of an oscillating system in SHM.

Q143. The wave that has the highest frequency and penetrating power is

• A. X-rays
• B. Ultraviolet rays
• C. Gamma rays✓
• D. Microwaves

Explanation: Gamma rays are the most energetic form of electromagnetic radiation, having the highest frequency, which allows them to penetrate dense materials such as lead and concrete. X-rays, while also capable of penetrating materials, do so at a lower frequency and energy level than gamma rays. Ultraviolet rays have a frequency higher than visible light but lower than X-rays and gamma rays, limiting their penetrating power. Microwaves, with even lower frequencies, are primarily used for communication and heating food, making them the least penetrating of the options provided.

Q144. According to First law of thermodynamics when heat flows into a system and no work is done, the internal energy of the system must

• A. Increase✓
• B. Decrease
• C. Remains constant
• D. Becomes zero

Explanation: The First Law of Thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system. In this scenario, since no work is done, the change in internal energy is purely due to the heat flowing into the system. Therefore, when heat flows into the system, the internal energy must increase. Option B is incorrect because it suggests a decrease in internal energy, which contradicts the principle that adding heat increases internal energy. Option C is also incorrect, as it implies that internal energy remains constant despite the addition of heat. Lastly, Option D is incorrect because it suggests that internal energy can become zero, which is not possible in this context as heat is being added.

Q145. If the length of the conductor is made 4 times its original length, its resistance becomes

• A. Quarter
• B. Half
• C. Zero
• D. 4 times✓

Explanation: The resistance of a conductor is given by the formula R = ρ(L/A), where R is resistance, ρ is resistivity, L is length, and A is cross-sectional area. From this relationship, we can see that resistance is directly proportional to the length of the conductor. If the length of the conductor is increased to four times its original length (4L), the new resistance can be expressed as: R' = ρ(4L/A) = 4(ρ(L/A)) = 4R Thus, the resistance becomes four times greater than its original value. The other options are incorrect because they misinterpret the relationship between length and resistance.

Q146. The unit of temperature coefficient of resistivity is

• A. 1/C
• B. 1/K✓
• C. 1/A
• D. 1/Ω

Explanation: The temperature coefficient of resistivity is a measure of how much the resistivity of a material changes with temperature. The correct unit for this coefficient is 1/K, which represents the change in resistivity per unit temperature change in Kelvin. Options A, C, and D are incorrect because they suggest units that do not apply to the temperature coefficient of resistivity: 1/C is not a standard unit, 1/A relates to electric current, and 1/Ω relates to resistance. Therefore, only 1/K correctly represents the temperature coefficient of resistivity.

Q147. The work done by the gravitational force on an object as it moves from a reference level to a higher point is:

• A. Always positive
• B. Always negative✓
• C. Zero
• D. Depends on the path taken

Explanation: The correct answer is that the work done by the gravitational force on an object moving from a reference level to a higher point is always negative. This is because work is defined as the product of the force applied and the displacement in the direction of the force. Since the gravitational force acts downward while the object is moving upward, the work done by gravity is negative. Option A is incorrect because the work done is not always positive; it can be negative when moving against the gravitational force. Option C is incorrect because work done is not zero; there is a displacement involved. Option D is also incorrect because the work done by gravity is determined solely by the change in height, independent of the path taken.

Q148. If two speakers emit sound at same frequency and phase, maximum loudness occurs when:

• A. Path difference = λ/2
• B. Path difference = λ✓
• C. Path difference = λ/4
• D. Path difference = 3λ/4

Explanation: When two waves are emitted from speakers at the same frequency and phase, they can interfere with each other. For maximum loudness, the path difference between the waves must be a whole number multiple of the wavelength (λ). Therefore, the correct answer is that a path difference of λ leads to constructive interference, producing maximum loudness.Options A, C, and D describe conditions that lead to various degrees of destructive interference, resulting in lower sound intensity. Specifically, λ/2 represents complete cancellation (destructive interference), λ/4 leads to partial cancellation, and 3λ/4 also results in destructive interference. Thus, only a path difference of λ results in the desired maximum loudness.

Q149. When an object attains terminal velocity, its acceleration is:

• A. 9.8 m/s2
• B. Zero✓
• C. 1 m/s2
• D. 9.8 m/s

Explanation: When an object reaches terminal velocity, it means that the downward force of gravity is balanced by the upward force of drag, resulting in no net force acting on the object. This balance leads to an acceleration of zero. Therefore, the correct answer is zero acceleration. The other options are incorrect because they either represent acceleration due to gravity (which is not applicable when terminal velocity is reached), a non-zero acceleration value, or a speed measurement. In essence, at terminal velocity, despite the object moving at a constant speed, its acceleration is zero.

Q150. A 0.5 kg ball moving at 6 m/s has kinetic energy

• A. 9 J✓
• B. 18 J
• C. 6 J
• D. 3 J

Explanation: The correct answer is 9 J, calculated using the kinetic energy formula KE = 0.5 * m * v². Substituting the given values: KE = 0.5 * 0.5 kg * (6 m/s)² results in KE = 0.5 * 0.5 * 36 = 9 J. Options B (18 J), C (6 J), and D (3 J) are incorrect because they fail to apply the formula correctly or misinterpret the mass and velocity values.

Q151. A fluid is flowing through a tube, to undergo transition from laminar to turbulent flow it's velocity must be:

• A. Slightly less than critical velocity
• B. Equal to critical velocity
• C. Greater than critical velocity✓
• D. Increasing gradually but less than critical velocity

Explanation: The correct answer is that for a fluid to transition from laminar to turbulent flow, its velocity must be greater than critical velocity. Critical velocity is a threshold value that indicates the transition point; below this value, flow remains orderly and laminar. Options A, B, and D all suggest velocities that are either less than or equal to critical velocity, which would not produce turbulent flow. Therefore, only Option C correctly identifies the necessary condition for the transition to turbulence.

Q152. For two equal positive charges, the electric field weakest?

• A. Midway between them✓
• B. Along the perpendicular bisector
• C. Close to either charge
• D. At infinity

Explanation: The correct answer is Midway between them. At this point, the electric fields due to both positive charges are equal in magnitude but opposite in direction, leading to cancellation of the fields and therefore the weakest electric field. The other options are incorrect because:Along the perpendicular bisector: The electric field is still present here and does not achieve its weakest point.Close to either charge: The field strength is strong at this location due to the proximity to the point charge.At infinity: The electric field does approach zero, but it is not the weakest point when considering the interaction of the two charges.

Q153. A projectile is launched in air with certain angle; its velocity is maximum at:

• A. Point of projection✓
• B. Highest point
• C. Between launching and highest point
• D. At all points

Explanation: The correct answer is the Point of projection. When the projectile is launched, it begins with the maximum initial velocity, which decreases as it travels upward due to the downward force of gravity. At the highest point of the trajectory, the vertical component of the velocity becomes zero, and while there is still a horizontal component, the overall velocity is not at its maximum. In the phase between launching and the highest point, the projectile is still losing vertical speed, further confirming that the maximum velocity occurs at the launch. The idea that velocity is the same at all points is incorrect, as it varies throughout the flight.

Q154. If the distance between two charges is halved and magnitude of charges are also doubled, then the force between these charges becomes:

• A. two times
• B. four times
• C. eight times
• D. sixteen times✓

Explanation: According to Coulomb's Law, the electric force (F) between two charges (q1 and q2) separated by a distance (r) can be expressed as: F = k * (|q1 * q2|) / r^2. In this scenario, if the distance (r) is halved, then r becomes r/2. Additionally, if the charges (q1 and q2) are doubled, they become 2q1 and 2q2. Substituting these values into the equation yields: F' = k * (|2q1 * 2q2|) / (r/2)^2 = k * (4|q1 * q2|) / (r^2 / 4) = k * (4|q1 * q2|) * (4 / r^2) = 16 * (k * |q1 * q2| / r^2) = 16F.This shows that the new force is 16 times the original force. Thus, Option A (two times), Option B (four times), and Option C (eight times) are incorrect as they do not take into account the combined effects of both changes accurately.

Q155. If a body having mass m1 (2kg), moving with 5 m/s approaches another mass,m2 (3kg) with speed of 1 m/s in same direction, relative speed of approach is 4 m/s. Relative speed of separation after collision will be:

• A. 4 m/s✓
• B. 2 m/s
• C. 6 m/s
• D. depends on masses

Explanation: In the given problem, we have two masses, m1 = 2kg and m2 = 3kg, approaching each other with speeds of 5 m/s and 1 m/s, respectively. The relative speed of approach is calculated as the difference in their speeds, which is 5 m/s - 1 m/s = 4 m/s. In an elastic collision, the principle states that the relative speed of separation after the collision is equal to the relative speed of approach. Hence, the relative speed of separation will also be 4 m/s, making Option A the correct answer. The other options are incorrect due to the principles of momentum and energy conservation in elastic collisions, which do not allow for arbitrary differences in speeds post-collision.

Q156. If P is the momentum of an object and m is its mass, then its kinetic energy is:

• A. P/2m
• B. P2/2m✓
• C. 1/2 Pm2
• D. 1/2 P2m

Explanation: The correct formula for kinetic energy (KE) in terms of momentum (P) and mass (m) is given by KE = P2/(2m). This derivation comes from the definition of momentum as P = mv, where v is velocity, and substituting this into the kinetic energy formula KE = 1/2 mv2 leads to the correct expression. Option A (P/2m) is incorrect as it misrepresents the relationship by failing to square the momentum. Option C (1/2 Pm2) misplaces the mass term, and Option D (1/2 P2m) overcomplicates the formula by incorrectly combining momentum and mass. Therefore, Option B is the only correct choice.

Q157. The electric field at a point due to two equal and opposite charges is 100 N/C. If the magnitude of each charge is doubled then the electric field at that point becomes:

• A. 50 N/C
• B. 100 N/C
• C. 200 N/C✓
• D. 400 N/C

Explanation: The electric field (E) due to a point charge (Q) is given by the formula E = k * Q / r^2, where k is Coulomb's constant and r is the distance from the charge to the point in question. In this case, we start with two equal and opposite charges, each producing a net electric field of 100 N/C. When the magnitudes of both charges are doubled, the formula indicates that the resultant electric field will also double, hence the new electric field becomes 200 N/C. Options A and B are incorrect as they suggest a decrease in the electric field, and Option D is incorrect as it implies a misunderstanding of the relationship between charge and electric field, suggesting a quadrupling instead of doubling.

Q158. If a plastic sheet of relative permittivity 2.5 is inserted between two point charges placed in a vacuum, then the electrostatic force between them

• A. Increases by a factor of 2.5
• B. Decreases by a factor of 2.5✓
• C. Increases by a factor of 5
• D. Decreases by a factor of 5

Explanation: When a dielectric material, such as a plastic sheet with a relative permittivity of 2.5, is inserted between two point charges, the electrostatic force between them decreases. This is due to the fact that the electric field in a dielectric medium is reduced by the factor of the material's relative permittivity. According to Coulomb's law, the electrostatic force is inversely proportional to the square of the distance between the charges and directly proportional to the product of the charges, but when a dielectric is introduced, the effective force is modified by the relative permittivity. Therefore, the force decreases by a factor of 2.5. Options A, C, and D are incorrect because they suggest an increase in force or a decrease by a different factor than the given relative permittivity, which does not reflect the behavior of electrostatic forces in dielectrics.

Q159. After 3 half-lives, the remaining fraction of a radioactive sample is:

• A. 1/2
• B. 1/4
• C. 1/8✓
• D. 1/16

Explanation: To determine the remaining fraction of a radioactive sample after a number of half-lives, use the formula (1/2)^n, where n is the number of half-lives. In this case, after 3 half-lives, the calculation is (1/2)^3 = 1/8. Therefore, the correct answer is 1/8. The other options do not reflect the fraction remaining after the specified number of half-lives: 1/2 is after 1 half-life, 1/4 is after 2 half-lives, and 1/16 is after 4 half-lives.

Q160. If the horizontal range of a projectile becomes half of its maximum possible horizontal range, the probable angle of projection is;

• A. 15o✓
• B. 30o
• C. 45o
• D. 60o

Explanation: The correct answer is 15o. The maximum horizontal range of a projectile occurs at an angle of 45o. When the horizontal range is half of this maximum range, the angle of projection can be calculated using the range equation. For an angle of 15o, the range is indeed half of the maximum possible range. The other options either yield the maximum range or do not produce a range that is half of the maximum, making them incorrect.

Q161. In an ideal transformer, if the primary voltage is doubled and the turns ratio remains the same, what happens to the secondary current?

• A. Doubles✓
• B. Halves
• C. Remains the same
• D. Becomes four times

Explanation: In an ideal transformer, the power input to the primary coil (Pprimary = Vprimary * Iprimary) is equal to the power output from the secondary coil (Psecondary = Vsecondary * Isecondary). Given that the turns ratio remains unchanged and the primary voltage is doubled, the secondary voltage will also increase proportionally. To keep the power balanced, the secondary current must also double. Therefore, the correct answer is that the secondary current doubles. Options B, C, and D are incorrect because they either misinterpret the relationship between voltage and current in an ideal transformer or suggest impossible scenarios based on the conservation of energy principle.

Q162. An angular displacement of 90o is equal to:

• A. One-fourth revolution✓
• B. One-third revolution
• C. One-half revolution
• D. One complete revolution

Explanation: An angular displacement of 90 degrees represents a quarter of a full circle, as a complete revolution is 360 degrees. Therefore, when you divide 90 by 360, you get 1/4, indicating that 90 degrees is one-fourth of a revolution. The other options do not accurately represent this fraction:One-third revolution (120 degrees) is incorrect as it exceeds 90 degrees.One-half revolution (180 degrees) is also incorrect as it is greater than 90 degrees.One complete revolution (360 degrees) is incorrect because it represents the full circle, not just the quarter indicated by 90 degrees.

Q163. A phase difference of 90o is equal to:

• A. n radians
• B. n/2 radians✓
• C. 2n radians
• D. n/4 radians

Explanation: A phase difference of 90 degrees is equivalent to π/2 radians. When expressed in terms of 'n', where n represents π (the full cycle in radians), this can be written as n/2 radians. Therefore, Option B is correct. The other options do not accurately express the conversion of 90 degrees into radians: Option A (n radians) does not relate to 90 degrees, Option C (2n radians) exceeds the equivalent, and Option D (n/4 radians) indicates a smaller phase difference.

Q164. The reciprocal of the resistivity of a material is called its:

• A. Impedance
• B. Conductivity✓
• C. Admittance
• D. Reactance

Explanation: The correct answer is Conductivity, as it is defined as the ability of a material to conduct electric current, which is indeed the reciprocal of resistivity. In simple terms, if a material has high resistivity, it has low conductivity and vice versa. Option A, Impedance, refers to the total opposition in a circuit, including resistance and reactance, but it is not related to resistivity. Option C, Admittance, relates to the ease of current flow in a circuit but is not the reciprocal of resistivity. Lastly, Option D, Reactance, specifically deals with opposition to alternating current due to reactive components and has no direct relation to resistivity.

Q165. The Balmer series of hydrogen spectrum appears in the

• A. Infrared region
• B. Ultraviolet region
• C. X-ray region
• D. Visible region✓

Explanation: The correct answer is the visible region. The Balmer series consists of spectral lines emitted by hydrogen when electrons transition from higher energy levels (n ≥ 3) to the second energy level (n = 2). The wavelengths of the light emitted during these transitions fall within the visible spectrum, which is why we can see the lines corresponding to this series. The other options are incorrect because:Infrared region: This region includes wavelengths longer than those of visible light, which do not correspond to the Balmer transitions.Ultraviolet region: While hydrogen does emit light in the ultraviolet range, these transitions are part of the Lyman series, not the Balmer series.X-ray region: This region involves much shorter wavelengths and is not associated with the transitions represented in the Balmer series.Thus, the Balmer series is uniquely defined by its visible light emissions from hydrogen.

Q166. A ball is thrown into the air with certain velocity v making an angle θ with horizontal. If air resistance is neglected, then at maximum height, its velocity is:

• A. Equal to initial velocity
• B. Half of initial velocity
• C. Equal to zero
• D. Minimum but not zero✓

Explanation: At maximum height, the projectile's vertical component of velocity decreases to zero due to the acceleration caused by gravity. However, the horizontal component of the velocity does not change when air resistance is neglected. Therefore, while the overall velocity reaches its minimum at this height, it is not equal to zero, as the horizontal component is still present. The other options incorrectly suggest that the overall velocity is either equal to the initial velocity (which ignores the effect of gravity), half of the initial velocity (which lacks justification), or completely zero (which disregards the horizontal motion).

Q167. A canon is placed on a smooth surface. When it fires a shell, the canon moves backward, this recoil occurs due to:

• A. Law of conservation of energy
• B. Backward thrust of the gases
• C. Newton's third law of motion✓
• D. Newton's first law of motion

Explanation: The correct answer is Newton's third law of motion. This law explains that for every action, there is an equal and opposite reaction. When the canon fires a shell, the gases produced exert a forward force on the shell, and simultaneously, the canon experiences an equal and opposite force, causing it to recoil backward. Option A is incorrect because the law of conservation of energy does not address the forces involved in the recoil. Option B, while it describes the physical phenomenon occurring, does not explain the underlying principle governing this interaction. Option D misapplies Newton's first law, which does not address the interaction of forces in this context.

Q168. Earth receives large amount of energy directly from:

• A. Wind
• B. Water
• C. Sun✓
• D. Moon

Explanation: The correct answer is Sun because it is the primary energy source for Earth, providing light and heat necessary for life and various natural processes. The Sun's energy drives photosynthesis, weather patterns, and climate, making it essential for the planet's ecosystems.Options such as Wind and Water refer to forms of energy or mediums that can be influenced by solar energy but are not direct sources of energy received from space. Moon does not provide energy; instead, it affects Earth through gravitational forces, especially in relation to tides.

Q169. The time in which half of the given number of radioactive nuclei decay is known as

• A. 1/2 life of radioactive element✓
• B. 2/3 life of radioactive element
• C. 3/4 life of radioactive element
• D. 2/5 life of radioactive element

Explanation: The correct answer is 1/2 life of radioactive element, also known simply as half-life. This term specifically denotes the time required for half of the radioactive nuclei in a sample to decay into a different state. The other options, such as 2/3 life, 3/4 life, and 2/5 life, do not correspond to any established definitions in the context of radioactive decay and are therefore incorrect. Understanding the concept of half-life is crucial in nuclear physics as it helps in predicting the behavior of radioactive materials over time.

Q170. If the surface charge density of an infinite sheet increases by 25% the electric field intensity:

• A. Increases by 25%✓
• B. Increases by 50%
• C. Decreases by 25%
• D. Remains the same

Explanation: The electric field intensity (E) due to an infinite sheet of charge is given by the formula E = σ / (2ε₀), where σ is the surface charge density and ε₀ is the permittivity of free space. When the surface charge density increases by 25%, the new charge density becomes 1.25σ. Substituting this into the formula, we find that the new electric field intensity becomes E' = 1.25σ / (2ε₀) = 1.25E, indicating that the electric field intensity increases by 25% as well. Therefore, Option A is correct. The other options incorrectly suggest other changes, but they do not reflect the direct proportionality between electric field intensity and surface charge density.

Q171. An incompressible fluid flows through a pipe that becomes narrower in one section. The fluid speed increases in that region to maintain:

• A. Constant pressure
• B. Constant energy
• C. Constant mass flow rate✓
• D. Constant volume

Explanation: The correct answer is Constant mass flow rate. According to the equation of continuity for incompressible fluids, the product of the cross-sectional area and the fluid speed must remain constant. Thus, when the pipe narrows (decreasing area), the fluid speed must increase to ensure that the mass flow rate remains constant. This is essential for the continuity of flow. The other options are incorrect because they misinterpret the principles of fluid dynamics: Constant pressure can vary with changes in speed; Constant energy is vague in this context as energy can change forms; and Constant volume is misleading as it does not directly relate to mass flow rate, which is the key concept here.

Q172. All daffodils are plants. All plants are living things. Some living things are real.Conclusions:I. All daffodils are living things.II. Some living things are flowers.III. All daffodils are real.Which conclusions follow?

• A. Only I✓
• B. Only I and II
• C. Only II and III
• D. All follow

Explanation: To solve this logical reasoning question, start by analyzing the relationships presented in the premises. The premises state that all daffodils are plants and that all plants are living things. Therefore, it is accurate to conclude that all daffodils are living things (Conclusion I). However, conclusion II states that 'Some living things are flowers,' which cannot be confirmed as true based solely on the information given; there is no direct link between living things and flowers established in the premises. Conclusion III, which suggests that 'All daffodils are real,' also cannot be affirmed since the premises only mention some living things being real, without stating that daffodils fall into that category. Thus, the only valid conclusion is I, making option A the correct answer.

Q173. One apple pie has 10 slices, and each apple pie feeds five people. Henry is having a party with 200 people. How many slices of pie does he need?

• A. 200
• B. 50
• C. 400✓
• D. 100

Explanation: To find the total number of slices needed for 200 people, we first note that one apple pie feeds five people. Therefore, to serve 200 people, Henry needs:Number of pies needed = Total guests / Guests per pie = 200 / 5 = 40 pies.Since each pie has 10 slices, the total number of slices required is:Total slices = Number of pies × Slices per pie = 40 × 10 = 400 slices.Thus, the correct answer is 400 slices. Options A, B, and D are incorrect as they underestimate the total number of slices needed for all guests.

Q174. How many trees are in the orchard?Which of the statements below are needed to sufficiently answer this question?i. Ibrahim is a farmer and looks after half of the trees in the orchardii. 300 trees in the orchard are under Ibrahim’s care

• A. i is enough
• B. ii is enough
• C. both i and ii are needed✓
• D. neither i nor ii are sufficient

Explanation: The correct answer is Option C: both i and ii are needed. Statement i informs us that Ibrahim takes care of half the trees in the orchard, while statement ii specifies that there are 300 trees under his care. To find the total number of trees, we can deduce that if 300 trees represent half, then the complete orchard must have 600 trees. Therefore, both statements work together to provide the necessary information. Options A and B are incorrect because each statement alone does not provide enough information to answer the question. Option D is also incorrect as both statements combined are indeed sufficient.

Q175. Asad bought 50 packets of biscuits for the price of Rs. 500; whereas Anum bought 25 packets of chips for the price of Rs. 1000. While comparing the prices of packets of biscuits and chips, which of the following statements is correct?

• A. Price of 4 packets of biscuits is equal to the price of 1 packet of chips✓
• B. Price of 1 packet of biscuits is equal to the price of 4 packets of chips
• C. Price of 2 packets of biscuits is equal to the price of 1 packet of chips
• D. Price of 1 packet of biscuits is equal to the price of 2 packets of chips

Explanation: To solve the problem, we first determine the cost per packet of biscuits and chips. For Asad, the cost per packet of biscuits is Rs. 10 (Rs. 500 / 50 packets), and for Anum, the cost per packet of chips is Rs. 40 (Rs. 1000 / 25 packets). Next, we compare the costs: 4 packets of biscuits cost Rs. 40 (4 x Rs. 10), which is equal to the cost of 1 packet of chips (Rs. 40). Thus, option A is correct. Options B, C, and D are incorrect as they misrepresent the relationship between the packet prices.

Q176. The virus spreads rapidly in the town. It infected the people – First day: 8, Second day: 16, Third day: 32. What will the number of people infected on the next day?

• A. 44 people
• B. 64 people✓
• C. 96 people
• D. 54 people

Explanation: On the first day, 8 people were infected. On the second day, this number doubled to 16. On the third day, it doubled again to 32. Observing this pattern, we can see that the number of infections is doubling each day. Therefore, on the fourth day, we would expect the number of infected people to double from 32 to 64 (32 x 2 = 64). The other options do not follow this doubling pattern, making them incorrect.

Q177. Which of the following is a result of poor design that could cause an accident in the workplace?

• A. Equipment failure
• B. Slippery surfaces✓
• C. Insufficient lighting
• D. Unplanned workspace layout

Explanation: The correct answer is Slippery surfaces because this is a clear consequence of poor design, typically resulting from inadequate materials or a lack of proper maintenance. Slippery surfaces can easily lead to slips and falls, making them a significant safety hazard in the workplace.In contrast, Equipment failure is generally associated with operational issues rather than design flaws, while Insufficient lighting is more a safety concern than a design issue. Lastly, Unplanned workspace layout can indeed lead to accidents, but it is less directly linked to design shortcomings when compared to slippery surfaces.

Q178. Which of the following is the main cause of accidents involving equipment?

• A. Overconfidence
• B. Insufficient maintenance✓
• C. Fatigue
• D. Poor training

Explanation: The correct answer is Insufficient maintenance. This is the main cause of accidents involving equipment, as lack of proper upkeep can lead to equipment failures or malfunctions that result in accidents. In contrast, while Overconfidence and Fatigue may contribute indirectly to accidents by affecting decision-making and performance, they do not directly cause equipment failures. Similarly, Poor training can lead to unsafe practices, but the immediate cause of accidents often stems from the condition of the equipment itself, which is directly impacted by maintenance. Regular maintenance ensures that equipment remains safe and functional, thus preventing accidents.

Q179. P, Q and R are M’s parents. M and N are siblings. Q is N’s mother. What is P to M?

• A. Mother
• B. Father✓
• C. Sister
• D. Brother

Explanation: In the question, P, Q, and R are identified as M's parents. Since Q is explicitly stated to be N's mother, and M and N are siblings, it follows that M's mother is Q. Thus, the only other parent left is P, which logically makes P M's father. Therefore, the correct answer is that P is M's father. The other options are incorrect as they misinterpret the relationships described in the question.

Q180. What will come next? 1, 4, 2, 5, 3, 6, 4, 7, ?

• A. 5✓
• B. 6
• C. 7
• D. 8

Explanation: The sequence alternates between two patterns: the first set increases by 1 (1, 2, 3, 4) and the second set increases by 1 starting from 4 (4, 5, 6, 7). The next number in the sequence, after 4 (from the first set), is 5. Therefore, the correct answer is 5. The other options do not follow the identified pattern and are incorrect.