Free Federal Mdcat Mock — Solved Past Paper with Answers

Q1. When the movie ended, everyone left the theater, but we stayed for the credits.

• A. Simple sentence
• B. Compound sentence
• C. Complex sentence
• D. Compound-Complex sentence✓

Explanation: (D) Compound-Complex sentence (Correct Answer) – Correct. This sentence has two independent clauses ("Everyone left the theater" and "we stayed for the credits") and one dependent clause ("When the movie ended"), making it a compound-complex sentence.

Q2. You should stick _ your promise.Choose the best option to fill in the blank.

• A. By
• B. To✓
• C. With
• D. In

Explanation: The preposition “To” is the correct answer here as it is used as an infinitive of purpose.

Q3. Choose the correct option. The injured player was taken _ the field.

• A. Off✓
• B. Of
• C. Out
• D. In

Explanation: “Off” is used here as it shows disconnection from a person, place or object, i.e away from someone or something, in this case the field.

Q4. The box is _ green outside and white inside.

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

Explanation: Since colors are referenced here, it means the correct option is “painted” as colors can only be painted onto things not carved or molded onto something.

Q5. To join the great majority means _.

• A. To accept a challenge and prepare for a fight
• B. To die✓
• C. To align with the majority's views
• D. To falsify an account to deceive

Explanation: The correct answer is To die. The idiom 'to join the great majority' is a euphemistic expression that means to pass away and join those who are deceased. The other options are incorrect as they suggest meanings unrelated to the idiomatic use of the phrase: accepting a challenge or fight, aligning with majority opinions, or engaging in deceitful actions do not capture the essence of this idiom.

Q6. Find the best relationship:Breath : Lungs

• A. Light : Bulb
• B. Food : Stomach✓
• C. Blood : Vein
• D. Water : Stream

Explanation: The correct answer is Food : Stomach because both pairs involve an intake process. Breath is taken into the lungs, and similarly, food is taken into the stomach for digestion. This is a direct and functional relationship. The other options do not share this characteristic of intake or absorption.

Q7. Neither they nor their friend _ solved the question.

• A. Has✓
• B. Have
• C. Was
• D. Were

Explanation: In 'neither-nor' constructions, the verb agrees with the subject closest to it. In this sentence, the subjects are 'they' and 'their friend.' Since 'friend' is closest to the verb and is singular, the verb 'has' is the correct choice, as it aligns with the singular subject. The option 'have' is incorrect as it would require a plural subject. 'Was' and 'were' are incorrect as they do not fit the present tense context.

Q8. He asked me _.

• A. How are you
• B. How was I
• C. How you are
• D. How I was✓

Explanation: The key to solving these questions is to read this sentence in your head while filling each option in the blank. The confusion here is between Options A and D. ‘how I was’ fits here well and how are you would have been used if this was being written as direct speech in quotation marks.

Q9. When your friend _, he'll be very tired.

• A. Arrived
• B. Arrives✓
• C. Will arrive
• D. Is arriving

Explanation: The correct answer is Option B: 'Arrives'. In this sentence, 'arrives' is used to describe an action that will happen in the future, following the structure of a conditional sentence. The future aspect is conveyed by 'he'll be very tired' (he will be very tired). Option A 'arrived' is incorrect because it is in the past tense, not fitting the future context. Option C 'will arrive' is unnecessary as the sentence already implies a future event. Option D 'is arriving' suggests a current ongoing action, which is not suitable here.

Q10. A decrease in blood pressure/volume will not cause the release of:

• A. Atrial natriuretic factor✓
• B. Aldosterone
• C. ADH
• D. Renin

Explanation: The correct answer is Atrial natriuretic factor (ANF). ANF is secreted by the atria of the heart in response to increased blood volume and pressure, not a decrease. It works to reduce blood volume and pressure by promoting sodium excretion and decreasing the release of aldosterone. On the other hand, Aldosterone, ADH, and Renin are all released in response to a decrease in blood pressure or volume. Aldosterone increases sodium reabsorption, ADH reduces water excretion, and renin triggers the renin-angiotensin-aldosterone system to increase blood pressure.

Q11. What forms the basis of DNA fingerprinting?

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

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

Q12. Tobacco plants resistant to a nematode have been developed by the introduction of DNA that produces (in the host cells):

• A. Both sense and anti-sense RNA✓
• B. A particular hormone
• C. An antifeedant
• D. A toxic protein

Explanation: Many nematodes live in plants and animals including human beings. A nematode Meloidogyne incognita infests the roots of tobacco plants and causes a great reduction in yield. A novel strategy was adopted to prevent this infection that was based on the process of RNA interference (RNAi). RNA interference (RNAi) is the phenomenon of inhibiting the activity of a gene by the synthesis of RNA molecules complementary to the mRNA. The normal (in vivo synthesized) mRNA of a gene is said to be “sense” because it carries the codons that are “read” during translation. Normally, the complement to the mRNA “sense” strand will not contain a sequence of codons that can be translated to produce a functional protein; thus, this complementary strand is called “anti­-sense RNA”. The anti-­sense RNA and mRNA molecules will anneal to form duplex RNA molecules (or double-stranded RNA) and the duplex RNA molecules can not be translated. Thus, the presence of anti­sense RNA will block translation of the mRNA of the affected gene. In fact, recent evidence indicates that these RNA duplexes are often rapidly degraded in vivo.

Q13. Consumption of which one of the following foods can prevent the kind of blindness associated with vitamin ‘A’ deficiency?

• A. ‘Flavr Savr’ tomato
• B. Canola
• C. Golden rice✓
• D. Bt­-Brinjal

Explanation: Golden rice is a genetically modified variety of rice (Oryza sativa) that has been engineered to produce beta-carotene, a precursor of vitamin A. This makes it a valuable food source in regions where vitamin A deficiency is prevalent, helping to prevent associated conditions such as blindness. In contrast, ‘Flavr Savr’ tomato is modified for shelf life, Canola is known for its heart health benefits due to its oil, and Bt-Brinjal is designed to resist certain pests rather than enhance nutritional content related to vitamin A.

Q14. Which one of the following vectors is used to replace the defective gene in gene therapy?

• A. Adenovirus✓
• B. Cosmid
• C. Ri plasmid
• D. Ti plasmid

Explanation: Gene therapy involves the insertion of normal genes into the cells of individuals with genetic disorders to correct or replace defective genes. Adenoviruses are commonly used as vectors in this process because they are capable of infecting a wide variety of human cells and can carry significant amounts of genetic material. They are engineered to be replication-deficient, ensuring they do not cause disease themselves.Cosmids, Ri plasmids, and Ti plasmids are not used in human gene therapy due to their specific applications in cloning and plant genetic engineering, which do not involve the efficient delivery of genes into human cells.

Q15. RNA interference involves the:

• A. Synthesis of complementary DNA and RNA using reverse transcriptase
• B. Silencing of specific mRNA due to complementary RNA✓
• C. Interference of RNA in the synthesis of DNA
• D. Synthesis of mRNA from DNA

Explanation: RNA interference (RNA) is the phenomenon of inhibiting the activity of a gene through the production of both sense and anti sense RNA. RNA takes place in all eukaryotic organisms as a method of cellular defense. This method involves specific mRNA silencing. It is due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA causing its silencing.

Q16. The crops engineered for glyphosate are resistant/tolerant to:

• A. Insects
• B. Herbicides✓
• C. Fungi
• D. Bacteria

Explanation: Glyphosate is a broad-spectrum herbicide that is highly effective in eliminating broad-leaved and grassy weeds. To prevent crop damage during herbicide application, crops are genetically modified to be glyphosate-tolerant. This way, when glyphosate is used, it targets the weeds without affecting the modified crops. Options A, C, and D relate to resistance against insects, fungi, and bacteria, respectively, which are not the purposes of glyphosate tolerance.

Q17. In Bt cotton, the Bt toxin present in plant tissue as protoxin is converted into active toxin due to:

• A. Action of gut microorganisms
• B. Presence of conversion factors in the insect gut
• C. Alkaline pH of the insect gut✓
• D. Acidic pH of the insect gut

Explanation: Soil bacterium Bacillus thuringiensis produces proteins that kill certain insects like lepidopterans (tobacco budworm, armyworm), coleopterans (beetles), and dipterans (flies, mosquitoes). B. thuringiensis forms some protein crystals which contain a toxic insecticidal protein. This toxin does not kill the Bacillus (bacterium) because it exists as inactive protoxins in them. But once an insect ingests it, it is converted into an active form of toxin due to the alkaline pH of the alimentary canal. The activated toxin binds to the surface of midgut epithelial cells and creates pores that cause swelling and lysis and finally cause the death of the insect.

Q18. Golden rice is a genetically modified crop plant where the incorporated gene is meant for the biosynthesis of:

• A. Omega-3
• B. Vitamin A✓
• C. Vitamin B
• D. Vitamin C

Explanation: Golden rice is a transgenic variety of rice (Oryza sativa) engineered to produce beta-carotene, a precursor to vitamin A. The grains appear yellow due to the presence of beta-carotene, hence the name 'golden rice.' This genetic modification is intended to combat vitamin A deficiency, which is prevalent in regions relying heavily on rice as a staple food. Options A, C, and D are incorrect because golden rice is not designed to address deficiencies in Omega-3, Vitamin B, or Vitamin C.

Q19. Which part of the tobacco plant is infected by Meloidogyne incognita?

• A. Stem
• B. Root✓
• C. Flower
• D. Leaf

Explanation: Meloidogyne incognita, commonly referred to as the root-knot nematode, infects the roots of the tobacco plant. The nematode is so named because it causes the formation of galls or knots on the roots, disrupting the plant's ability to absorb water and nutrients efficiently. This results in stunted growth and can significantly diminish crop yield. While the stem, leaves, and flowers may show signs of stress due to root damage, they are not directly infected by the nematode. Thus, the root is the primary site of infection.

Q20. Which kind of therapy was given in 1990 to a four­ year­ girl with Adenosine Deaminase (ADA) enzyme deficiency?

• A. Gene therapy✓
• B. Chemotherapy
• C. Immunotherapy
• D. Radiation therapy

Explanation: Gene therapy is a technique of genetic engineering which involves the replacement of a faulty/disease-causing gene by a normal healthy functional gene. The first clinical ex-vivo gene therapy was given in 1990 to a 4­-year old girl with adenosine deaminase (ADA) enzyme deficiency. This enzyme is very important for the immune system to function and the deficiency of this enzyme can lead to severe combined immune deficiency (SCID).

Q21. Which one has the thicker walls than the others?

• A. Right atria
• B. Left atria
• C. Right ventricle
• D. Left ventricle✓

Explanation: The left ventricle has the thickest walls to generate enough force to pump oxygenated blood through the entire systemic circulation, unlike the right ventricle, which only pumps to the lungs.

Q22. Oxygenated blood is supplied to all body parts from:

• A. Right atrium
• B. Left atrium
• C. Right ventricle
• D. Left ventricle✓

Explanation: The left ventricle is the main pumping chamber of the heart, responsible for distributing oxygenated blood to the body. It receives oxygenated blood from the left atrium and pumps it through the aorta. The other options are incorrect because the right atrium and right ventricle handle deoxygenated blood, while the left atrium only transfers oxygenated blood to the left ventricle without directly supplying it to the body.

Q23. Which of these is correct about thoracic duct?

• A. It arises in the vessels of the brain
• B. It drains the entire body above the diaphragm
• C. It empties its contents into the subclavian vein✓
• D. It carries blood into the lymphatic system

Explanation: The thoracic duct, also known as the left lymphatic duct, is the largest lymphatic vessel in the human body. It collects lymph from the lower limbs, pelvis, abdomen, left side of the chest, left arm, and left side of the head and neck. The thoracic duct then empties this lymph into the left subclavian vein, integrating it back into the circulatory system. This makes option C correct. Option A is incorrect because the thoracic duct does not originate in the brain. Option B is incorrect because it does not drain the entire body above the diaphragm, only the left side. Option D is incorrect because it does not carry blood into the lymphatic system, but rather transports lymph into the venous system.

Q24. Lymphocyte B and T have been named due to their:

• A. Relationship with bursa of Fabricius and thymus gland respectively✓
• B. Origin from bursa Fabricius and thymus, respectively
• C. Storage in bursa of Fabricius and thymus
• D. Destruction in bursa of Fabricius

Explanation: B cells were first discovered in the bursa of Fabricius (birds), and T cells mature in thymus.

Q25. Thymus gland provides immunological competence to:

• A. B-lymphocytes
• B. Antibodies
• C. T-lymphocytes✓
• D. Immunoglobulins

Explanation: The thymus gland is crucial for the maturation of T-lymphocytes, which are essential components of the adaptive immune system. In the thymus, T-lymphocytes undergo a process that equips them with the ability to recognize and respond to specific antigens, thus achieving immunological competence. On the other hand, B-lymphocytes are produced and mature in the bone marrow, where they differentiate independently of the thymus. Antibodies and immunoglobulins are produced by B-lymphocyte-derived plasma cells and do not directly involve the thymus in their production or function.

Q26. An antibody molecule consists of:

• A. Two identical light chains only
• B. Two identical heavy chains only
• C. Two identical light and two identical heavy chains✓
• D. Two identical light chains and two non-identical heavy chains

Explanation: An antibody molecule, also known as an immunoglobulin, is a Y-shaped protein that plays a critical role in the immune response by recognizing and binding to antigens. Its structure includes two identical light chains and two identical heavy chains, which are connected by disulfide bonds. This configuration allows antibodies to specifically bind to antigens. Option A is incorrect because it only mentions light chains. Option B is incorrect because it only mentions heavy chains. Option D is incorrect because it suggests the heavy chains are non-identical, which is not the case.

Q27. In light chain of antibodies:

• A. The variable sequence of amino acids is longer.
• B. The variable sequence of amino acids is shorter.✓
• C. Both variable and constant amino acid sequences have equal length.
• D. Only the variable sequence of amino acids occurs.

Explanation: The light chain of an antibody consists of both variable and constant regions. The variable region is shorter in terms of sequence length but is highly diverse to enable the recognition of a wide variety of antigens, which is crucial for the adaptive immune response. The constant region provides structural stability. Option B is correct because it correctly identifies the typical structure of the light chain, while the other options either misinterpret the structural differences or incorrectly describe the presence or absence of these regions.

Q28. Globular blood proteins that are produced by B-lymphocytes and that bind specifically to foreign antigenic materials in the body and destroy them are called:

• A. Antigens
• B. Immunogens
• C. Antibodies✓
• D. Antibiotics

Explanation: An antibody (Ab), also known as an immunoglobulin (Ig), is a large Y-shaped protein produced mainly by plasma cells that is used by the immune system to identify and neutralize pathogens such as bacteria and viruses. The antibody recognizes a unique molecule of the harmful agent, called antigen, via variable region.

Q29. When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe?

• A. Falling CO2 concentration
• B. Rising CO2 and falling O2 concentration
• C. Falling O2 concentration
• D. Rising CO2 concentration✓

Explanation: During breath-holding, the accumulation of CO in the blood is the primary factor that triggers the urge to breathe. This rise in CO concentration stimulates the respiratory center in the brain, prompting the body to resume breathing to expel excess CO and maintain homeostasis.

Q30. Name the pulmonary disease in which alveolar surface area involved in gas exchange is drastically reduced due to damage in the alveolar walls:

• A. Pneumonia
• B. Asthma
• C. Pleurisy
• D. Emphysema✓

Explanation: In emphysema, the walls of the alveoli are damaged, leading to fewer and larger air sacs instead of many small ones. This reduces the surface area for gas exchange and causes breathing difficulties.

Q31. Asthma may be attributed to:

• A. Inflammation of the trachea
• B. Accumulation of fluid in the lungs
• C. Bacterial infection of the lungs
• D. Allergic reaction of the mast cells in the lungs✓

Explanation: Asthma is often associated with allergic reactions where allergens trigger the activation of mast cells in the lungs. These cells release chemicals like histamines, leading to airway inflammation and bronchoconstriction, which are hallmarks of asthma.

Q32. Name the chronic respiratory disorder caused mainly by cigarette smoking.

• A. Respiratory acidosis
• B. Respiratory alkalosis
• C. Emphysema✓
• D. Asthma

Explanation: Emphysema is a chronic respiratory disorder primarily caused by cigarette smoking, leading to damaged lung tissue and breathing difficulties.

Q33. Reduction in pH of blood will directly cause which of the following?

• A. Decrease the affinity of haemoglobin with oxygen✓
• B. Release bicarbonate ions by the liver
• C. Reduce the rate of heart beat
• D. Reduce the blood supply to the brain.

Explanation: A reduction in blood pH (an increase in acidity) is typically associated with a condition called acidosis. In acidosis, the affinity of hemoglobin for oxygen decreases. This means that hemoglobin is less effective at binding with oxygen, which can lead to impaired oxygen transport to tissues.

Q34. Lungs do not collapse between breaths, and some air always remains in the lungs, which can never be expelled because:

• A. There is a negative pressure in the lungs
• B. There is a negative intrapleural pressure pulling at the lung walls✓
• C. There is a positive intrapleural pressure
• D. Pressure in the lungs is higher than atmospheric pressure

Explanation: Option B is correct.All options are explained below:a)There is a negative pressure in the lungs."This statement is not entirely accurate. Lungs don't naturally have a negative pressure, and they can't be filled with air if there is a consistent negative pressure. Lungs maintain a degree of positive pressure to keep them expanded.b) "There is a negative intrapleural pressure pulling at the lung walls": This option is correct. Between breaths, the lungs do not collapse due to the presence of a negative intrapleural pressure. Intrapleural pressure is the pressure in the pleural cavity, which surrounds the lungs. It is typically lower than atmospheric pressure, creating a "suction" effect that keeps the lungs inflated. This is a key mechanism for lung expansion and prevents lung collapse.c)"There is a positive intrapleural pressure": This statement is not accurate. A positive intrapleural pressure would not be conducive to maintaining lung expansion; it's the negative intrapleural pressure that plays a critical role in preventing lung collapse.d)"Pressure in the lungs is higher than the atmospheric pressure": This is not correct. The pressure in the lungs, during exhalation, is generally close to atmospheric pressure, but it's the intrapleural pressure that is negative, not the pressure in the lungs themselves.Summary: The correct answer is: "There is a negative intrapleural pressure pulling at the lung walls." The negative intrapleural pressure, which is lower than atmospheric pressure, keeps the lungs expanded by exerting a suction effect on the lung walls, preventing lung collapse between breaths.

Q35. The partial pressure of oxygen in the alveoli of the lungs is:

• A. Equal to that in the blood
• B. More than that in the blood✓
• C. Less than that in the blood
• D. Less than that of carbon dioxide.

Explanation: The partial pressure of oxygen in the alveoli is higher than in the blood, facilitating the diffusion of oxygen from the alveoli into the blood, where it can be transported by hemoglobin to tissues throughout the body.

Q36. Lungs are made up of air­filled sacs, the alveoli. They do not collapse even after forceful expiration because of

• A. Inspiratory reserve volume
• B. Tidal volume
• C. Expiratory reserve volume
• D. Residual volume✓

Explanation: Even after a forceful expiration, a certain amount of air always remains in the lungs. This is called residual volume. It prevents the alveoli from collapsing completely, ensuring continuous exchange of gases (O₂ and CO₂) between breaths.

Q37. The oxygen-binding protein present in skeletal muscles is:

• A. Globin
• B. Glycogen
• C. Myoglycogen
• D. Myoglobin✓

Explanation: Myoglobin is a low molecular weight oxygen-binding heme protein that is found exclusively in the heart and skeletal muscle cells.

Q38. Which one of the following characteristics is common both in humans and adult frogs?

• A. Four chambered heart
• B. Internal fertilization
• C. Nucleated RBCs
• D. Ureotelic mode of excretion✓

Explanation: Excretion of urea is known as ureotelism and the animals which excrete urea are called ureotelic. Ureotelic animals include Ascaris, earthworm (both are ammonotelic and ureotelic), cartilaginous fishes like sharks and sting rays, semiaquatic amphibians such as frogs and toads, aquatic or semiaquatic reptiles like turtles, terrapins and alligators, and man and all other mammals. Urea is less toxic and less soluble in water than ammonia. Hence, it can stay for some time in the body. Amphibian tadpole (e.g., tadpole of frog) excrete ammonia but after metamorphosis frog excretes urea.

Q39. A fall in glomerular filtration rate (GFR) activates:

• A. Juxtaglomerular cells to release renin✓
• B. Adrenal cortex to release aldosterone
• C. Adrenal medulla to release adrenaline
• D. Posterior pituitary to release vasopressin

Explanation: Low GFR triggers renin release to maintain blood pressure.

Q40. The maximum amount of electrolytes and water (70 – 80 %) from the glomerular filtrate is reabsorbed in which part of the nephron?

• A. Ascending limb of loop of Henle
• B. Distal convoluted tubule
• C. Proximal convoluted tubule✓
• D. Descending limb of loop of Henle

Explanation: During glomerular filtration in kidneys, ultrafiltration of blood occurs i.e: almost all the constituents of plasma except proteins pass onto the Bowman’s capsule.Then nearly 99% of the filtrate is reabsorbed by renal tubules.The proximal convoluted tubules show maximum reabsorption and nearly all the essential nutrients and 70-80% of electrolytes and water are reabsorbed by this segment.

Q41. Which of the following does NOT favour the formation of large quantities of dilute urine?

• A. Renin✓
• B. Atrial Natriuretic Factor (ANF)
• C. Alcohol
• D. Caffeine

Explanation: Renin promotes sodium/water retention, reducing dilute urine formation.

Q42. The part of the nephron involved in active reabsorption of sodium is:

• A. Distal convoluted tubule
• B. Ascending loop of Henle✓
• C. Bowman’s capsule
• D. Descending limb of Henle’s loop

Explanation: The correct answer is the ascending loop of Henle, which is crucial for the active reabsorption of sodium ions from the filtrate back into the bloodstream. This segment utilizes active transport mechanisms to move sodium ions against their concentration gradient, which is essential for maintaining osmotic balance and blood pressure.The distal convoluted tubule causes gradual osmotic outlow of water from the iltrate back to kidney as it passes downward in the descending loop of Henle. Bowman's capsule serves a different function by filtering blood but does not participate in sodium reabsorption. Finally, the descending limb of Henle's loop is primarily involved in the passive reabsorption of water, making it ineffective for sodium reabsorption.

Q43. Which of the following is the correct statement?

• A. The descending limb of loop of Henle is impermeable to water.
• B. The ascending limb of loop of Henle is permeable to water.
• C. The descending limb of loop of Henle is permeable to electrolytes.
• D. The ascending limb of loop of Henle is impermeable to water.✓

Explanation: The key difference between ascending and descending loop of Henle is that the ascending loop of Henle is the thicker segment of the loop of Henle located just after the sharp bend of the loop while descending loop of Henle is the thinner segment located just before the sharp bend of the loop. The descending limb of the loop of Henle is permeable to water. Water diffuses into the hyperosmolar medullary interstitium.

Q44. Which one of the following is not a part of a renal pyramid?

• A. Peritubular capillaries
• B. Convoluted tubules✓
• C. Collecting ducts
• D. Loop of Henle

Explanation: Convoluted tubules are in renal cortex, not in pyramids.

Q45. Which of the following helps in maintaining balance?

• A. Hypothalamus
• B. Medulla Oblongata
• C. Cerebellum✓
• D. Pons

Explanation: The cerebellum is a part of the hindbrain that helps in maintaining the posture and balance of the body. The hypothalamus has several endocrine functions involving thermoregulation. Pons regulate the sleep-wake cycle. Medulla Oblongata controls involuntary movements such as breathing, heart rate, etc.

Q46. Pulmonary veins supply blood to the heart chamber:

• A. Right atrium
• B. Left atrium✓
• C. Right ventricle
• D. Left ventricle

Explanation: The oxygenated blood is brought back to the heart by the pulmonary veins which enter the left atrium. From the left atrium, blood flows into the left ventricle. The left ventricle pumps the blood to the aorta which will distribute the oxygenated blood to all parts of the body.

Q47. Sensation of pleasure, punishment, or sexual arousal are stimulated by the parts of the brain:

• A. Hippocampus
• B. Hypothalamus
• C. Amygdala✓
• D. Thalamus

Explanation: The amygdala controls the sensation of pleasure, punishment, or sexual arousal. The hippocampus has a major role in learning and memory. The hypothalamus is considered to be a link structure between the nervous and the endocrine system; its main function is to maintain the homeostasis of the body. The thalamus has several functions, such as relaying of sensory signals, including motor signals, to the cerebral cortex and the regulation of consciousness, sleep, and alertness.

Q48. Germ Theory of disease was proposed by:

• A. Leeuwenhoek
• B. Louis Pasteur
• C. Walther Flemming
• D. Robert Koch✓
• E. Edward Jenner

Explanation: Option A: Antonie van Leeuwenhoek, a Dutch microscopist, was the first person to observe microorganisms in the 17th century. Option B: Louis Pasteur, a French chemist and microbiologist, conducted experiments that showed that microorganisms can cause fermentation and spoilage. He also developed vaccines for rabies and anthrax. Option C: Walther Flemming, a Danish biologist, discovered chromosomes and showed that they are made up of DNA. Option D: The germ theory of disease was proposed by Robert Koch. He is a German physician and microbiologist who is considered the "father of bacteriology". In the late 19th century, Koch developed four criteria, now known as Koch's postulates, to establish that a specific microorganism causes a specific disease. These criteria are still used today to confirm the cause of a disease. The germ theory of disease has revolutionized the way we understand and treat disease. It has led to the development of vaccines, antibiotics, and other treatments that have saved millions of live Option E: Edward Jenner, an English physician, developed the first vaccine against smallpox.

Q49. A woman with normal colour vision, whose father was red green colour blind, married a red green colour blind man. What is the probability of her born child being red green colour blind?

• A. 1.0
• B. 0.75
• C. 0.50✓
• D. 0.25

Explanation: Males have 1 X chromosome and 1 Y chromosome, and females have 2 X chromosomes. The genes that can give you red-green colour blindness are passed down on the X chromosome.The woman’s father is red-green colour blind. Since the woman got one of her X chromosomes from her father this means that she is a carrier. As it can be seen from the table the probability of having a colourblind child is 0.5%

Q50. In aerobic respiration most of the ATP is synthesized during:

• A. Oxidation of pyruvic acid
• B. Electron transport chain✓
• C. Krebs cycle
• D. Glycolysis

Explanation: The maximum ATP yield for a molecule of glucose is around 30-32 ATP. During glycolysis, from one glucose molecule, net 2 ATP molecules are produced. During oxidation of Pyruvic acid, no ATPs are produced. During Krebs cycle, for one glucose molecule, 2 ATPs are produced. Beyond those four, the remaining ATP all come from ETC during oxidative phosphorylation. The correct answer is, therefore, B.

Q51. Number of bones in skull is:

• A. 8
• B. 14
• C. 22✓
• D. 33

Explanation: The cranium has 8 bones. 14 bones are found in the fingers of each hand and also in the toes of each foot. The spine is made up of 33 vertebrae. Vertebrae are the 33 individual bones that interlock with each other to form the spinal column. The human skull contains 22 bones. The correct answer is, therefore, C.

Q52. The condition in which one of more genes that have no allelic counterpart is known as:

• A. Homozygous
• B. Hemizygous✓
• C. Heterozygous
• D. Incomplete dominance

Explanation: Hemizygous means having only a single copy of a gene instead of the customary two copies. All the genes on the single X chromosome in the male are hemizygous. Homozygous means having 2 identical alleles of a particular gene. Heterozygous means having 2 different alleles of a particular gene. Incomplete dominance is a form of Gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype. The correct answer is, therefore, B.

Q53. A woman can be bald only when she is

• A. Homozygous dominant
• B. Heterozygous
• C. Homozygous recessive✓
• D. None of these

Explanation: Pattern baldness is a sex-influenced trait, meaning its expression differs between males and females. In men, it is an autosomal dominant trait, allowing baldness to occur with just one dominant allele. However, in women, it is an autosomal recessive trait, which means baldness occurs only if the woman has two recessive alleles (homozygous recessive). This is why a woman can only be bald if she is homozygous recessive. The other genotypes, homozygous dominant and heterozygous, result in the dominant allele masking the recessive allele, preventing baldness in females.

Q54. Nictitating membrane is found in the _ and performs _function.

• A. Eyes … cleaning and protection✓
• B. Brain … processing
• C. Feet … balance
• D. Bones … structure

Explanation: The nictitating membrane is a semi-transparent third eyelid found in some animals, such as birds, reptiles, and some mammals. It serves to protect the eye from debris and helps keep it moist while allowing for vision. The other options are incorrect because the nictitating membrane is not involved in brain processing, balance, or structural support, which are functions of other body parts.

Q55. Which substance might include this molecule?

• A. Cellulose
• B. Cholesterol
• C. Glycerol✓
• D. Insulin

Explanation: Glycerol has three OH groups as it forms bonds with three fatty acid molecules.

Q56. Which of the following cell type is most appropriate to study mitochondria?

• A. RBC (Red Blood Cell)
• B. Muscle cell✓
• C. Mesophyll cell
• D. E.coli

Explanation: Muscle cells are highly active and require substantial amounts of ATP for contraction, which necessitates a high number of mitochondria. RBCs (red blood cells) in mammals do not contain mitochondria, as their primary function is to transport oxygen. Mesophyll cells, while involved in photosynthesis, do not have energy demands as high as muscle cells and therefore have fewer mitochondria. E.coli, being a prokaryote, lacks any membrane-bound organelles, including mitochondria.

Q57. Which of the following organelles is most abundant in those animal cells which exhibit phagocytic activity?

• A. Golgi apparatus
• B. Cell wall
• C. Lysosomes✓
• D. None of these

Explanation: Lysosomes are crucial for phagocytic cells because they contain hydrolytic enzymes that digest foreign particles engulfed by the cell. These enzymes are essential for breaking down the contents of the phagosome, which is the vesicle formed around the ingested material. Other organelles, like the Golgi apparatus, are not directly involved in this process. Animal cells do not have a cell wall, and the option 'None of these' is incorrect as lysosomes are indeed the correct answer.

Q58. Four words are shown below:Branchioceranthus - sexual reproduction - nutritive - HydraThese words can be used in the spaces P, Q, R, and S to complete the sentence below:The coelenterates range in size from microscopic _P_ to macroscopic, _Q_, a hydrozoan polyp that may reach two meters in length. Cnidarians are found in two basic forms: the polyps and the medusae. Polyps are cylindrical animals, which in most cases are _R_ in function, hence named as gastrozooids. The medusae are umbrella-like in form. These are free-swimming. The medusae are involved in _S_ as they have gonads.

• A. Option A
• B. Option B✓
• C. Option C
• D. Option D

Explanation: Branchioceranthus is macroscopic and hydra is microscopic. P = Hydra Q =Branchioceranthus R = nutritive S= Sexual reproduction

Q59. Retrovirus cause diseases in:

• A. Rodents
• B. Fowls
• C. Cats
• D. All of these✓

Explanation: The correct answer is d) All of these. Retroviruses have been identified to cause diseases in rodents, fowls, and cats. These viruses can have varying effects on different species, but they are known to be pathogenic and can lead to various health issues.

Q60. What is the function of the cholesterol in a cell surface membrane?

• A. Controlling active transport
• B. Acting as a membrane blood receptor
• C. Helping cells join together
• D. Regulating the flexibility at the membrane✓

Explanation: Cholesterol helps to regulate membrane fluidity over the range of physiological temperatures. It has a hydroxyl group that interacts with the polar head groups of the membrane phospholipids and sphingolipids. Therefore, the correct answer is D.

Q61. Sperms are produced in:

• A. Urethra
• B. Sperm dust
• C. Pancreas
• D. Testes✓

Explanation: The testes are the male reproductive organs responsible for producing sperm through a process called spermatogenesis.

Q62. Gray matter of spinal cord does not contain:

• A. Cell bodies of sensory neurons✓
• B. Cell bodies of interneurons
• C. Axons of interneurons
• D. Cell bodies of motor neurons

Explanation: Gray matter, the inner matter of the spinal cord does not contain cell bodies of sensory neurons.

Q63. Porins are present in:

• A. Mitochondria and golgi apparatus
• B. Mitochondria and chloroplast✓
• C. Mitochondria and ribosomes
• D. Golgi apparatus and chloroplast

Explanation: Mitochondria: The outer mitochondrial membrane contains porins called Voltage-Dependent Anion Channels (VDACs), which allow the passage of ions and small molecules into the intermembrane space.* Chloroplasts: Porins are also present in the outer membrane of chloroplasts, facilitating the transport of metabolites and ions across the membrane.

Q64. As the pH of blood decreases, H+ ions increase, which combine with the protein part of hemoglobin to reduce its ability to bind with:

• A. O2✓
• B. CO2
• C. CO
• D. H2

Explanation: If the pH of blood is lower than normal (normal physiological pH is 7.4), then the haemoglobin does not bind oxygen as well. In other words, the lower the pH, the more Hydrogen ions, the higher the carbon dioxide level and the LESS affinity Hemoglobin has for oxygen. The opposite is also true: the higher the pH lower the H+ ion concentration, the lower the carbon dioxide level, and the greater the affinity of haemoglobin for oxygen.

Q65. Which combination describes a triglyceride?

• A. Option A✓
• B. Option B
• C. Option C
• D. Option D

Explanation: Triglyceride being nonpolar do not dissolve in water hence are insoluble in water; they do store a lot of energy in them; they do hydrolyze to release water, and being non-polar they can dissolve in organic solvents.Restriction enzyme, also called restriction endonuclease, a protein produced by bacteria that cleaves DNA at specific sites along the molecule. In the bacterial cell, restriction enzymes cleave foreign DNA, thus eliminating infecting organisms.

Q66. First step of viral replication is:

• A. Entry
• B. Assembly
• C. Uncoating
• D. Adsorption or Attachment✓

Explanation: Viral infections follow similar steps in the virus replication cycle: attachment or adsorption, penetration, uncoating, replication, assembly, and release.

Q67. The axial skeleton of an adult human includes:

• A. The skull, pectoral girdle, and ribs
• B. The skull, ribs, and bones of arms and legs
• C. The pectoral and pelvic girdles
• D. The ribs, the skull, the sternum, and the vertebrae✓

Explanation: The axial skeleton involves the ribs, skull, sternum, and vertebrae.

Q68. What explains the effect on a red blood cell of being placed into pure water?

• A. Less water leaves the cell than enters it, so the cell shrinks.
• B. More water enters the cell than leaves it, so the cell swells and bursts.✓
• C. Water enters the cells and none leaves it, so the cell swells and bursts.
• D. Water enters the cell and more leaves it, so the cell shrinks.

Explanation: b) More water enters the cell than leaves it, so the cell swells and bursts:This option is partially correct. When a red blood cell is placed into pure water, water molecules will move into the cell by osmosis. The influx of water will cause the cell to swell. However, under normal conditions, a red blood cell has a flexible membrane that can stretch to accommodate the influx of water, preventing the cell from bursting.

Q69. Which statement about a triglyceride molecule are correct?1. It always contains unsaturated hydrocarbon tails2. It is formed using ester bonds3. It does not form hydrogen bonds4. It contains a hydrophilic glycerol head

• A. 1, 2 and 3
• B. 2, 1 and 4
• C. 1 and 4 only
• D. 2 and 3 only✓

Explanation: Triglycerides are formed by linking fatty acids with an ester linkage to three alcohol groups in glycerol. Triglycerides are hydrophobic and so insoluble in water. The charges are evenly distributed around the molecule so hydrogen bonds to not form with water molecules. The correct answer is, therefore, D.

Q70. In term of enzyme actions, 'maximum temperature' refers to a temperature at which:

• A. A. Enzymes start to denature✓
• B. B. Enzymes start to re-nature
• C. C. Enzymes work best
• D. D. Enzymes are reactivated

Explanation: The term 'maximum temperature' indicates the point at which enzymes begin to denature, meaning they lose their functional shape due to heat (Option A). When enzymes denature, they can no longer catalyze reactions effectively. Option B is incorrect because enzymes do not start to re-nature at maximum temperatures; they are still denaturing. Option C is misleading, as enzymes do not work optimally at maximum temperature but rather at their specific optimal temperature. Option D is also incorrect since reactivation occurs after denaturation under favorable conditions, not at the point of maximum temperature.

Q71. The chemical which regulates the enzymatic activity is:

• A. Activator
• B. Inhibitor
• C. Substrate
• D. Both A and B✓

Explanation: Enzymes can be regulated by other molecules that either increase or reduce their activity. Molecules that increase the activity of an enzyme are called activators, while molecules that decrease the activity of an enzyme are called inhibitors.

Q72. Virus recognize host through:

• A. Envelope
• B. DNA
• C. Capsid
• D. Protein Coat✓

Explanation: A virus’ protein coat contains receptors. The virus recognizes and binds to a host cell via a receptor. The virus or its genetic material then enters the host cell. The envelope itself is derived from the host.

Q73. Cell surface markers are

• A. Lipoproteins
• B. Glycolipids
• C. Sphingolipids
• D. Glycoproteins
• E. both b and d✓

Explanation: The correct answer is both b and d because both glycolipids and glycoproteins are classified as cell surface markers. Glycolipids are lipids with carbohydrate groups attached, found on the outer surface of cell membranes, playing critical roles in cell recognition and signaling. Glycoproteins, on the other hand, are proteins that have carbohydrates covalently bonded to them, and they also function in recognition and signaling processes at the cell surface. In contrast, lipoproteins primarily function in lipid transport in the bloodstream and are not cell surface markers. Sphingolipids, while important for membrane structure and signaling, are not specifically known as markers for cell recognition.

Q74. A mammalian cell contains 70% of:

• A. DNA
• B. Protein
• C. RNA
• D. Water✓

Explanation: (d) Water (Correct Answer) – Water is the most abundant component of a mammalian cell, making up around 70% of its mass

Q75. Role of lysosomes include:

• A. Store hydrolytic enzymes
• B. Perform autophagy
• C. Destruction of cell
• D. All of above✓

Explanation: Lysosomes store hydrolytic enzymes, which play their role in autophagy and destruction of old cells. Hence, the correct option is D.

Q76. The haploid number of chromosomes in human beings:

• A. 4
• B. 10
• C. 24
• D. 23✓

Explanation: The correct answer is 23. In humans, somatic cells contain 46 chromosomes, which is the diploid number. Gametes, such as sperm and eggs, contain the haploid number of chromosomes, which is half of the diploid number, resulting in 23 chromosomes. This ensures that when fertilization occurs, the resultant zygote will have 46 chromosomes. The other options are incorrect because they do not reflect the accurate division of the diploid number in humans.

Q77. Which of the following correctly shows structures which are found in a eukaryotic cell? (Yes = present ; No = absent)

• A. Option A
• B. Option B
• C. Option C
• D. Option D
• E. Option E✓

Explanation: The question asks for eukaryotic cells, which possess a nucleus as well as other membrane bound organelles such as mitochondria, lysosomes, golgi apparatus, endoplasmic reticulum in addition to (80S) ribosomes. Only option E fulfills this criteria, as all other options have one or more of the components missing.

Q78. The RNA found in Ribosomes is:

• A. mRNA
• B. rRNA✓
• C. tRNA
• D. Polysome
• E. Genes

Explanation: Ribosomal RNA (rRNA) is the most abundant type of RNA in cells. It is found in ribosomes, which are the cellular structures that are responsible for protein synthesis. rRNA makes up about 80% of the mass of ribosomes. They are made up of two subunits, a large subunit and a small subunit. Both subunits contain rRNA, as well as a number of proteins. It is involved in the assembly of ribosomes and in the translation of mRNA into proteins.

Q79. In humans,_ is responsible for producing cell's hydrogen peroxide.

• A. Lysosomes
• B. Mitochondria
• C. Peroxisomes✓
• D. glyoxysome

Explanation: The main chemical produced by oxidation in peroxisomes is the very cytotoxic (cell toxic) hydrogen peroxide. Fortunately peroxisomes produce copious amounts of the enzyme catalase and this helps break down hydrogen peroxide to water and oxygen.

Q80. HIV-I protease is an enzyme produced by the HIV virus. Two identical chains of 99 amino acids form the enzyme. In each chain, amino acids 25, 25 and 27 in the sequence form part of the active site. Which orders of protein structure control the shape of the active site?

• A. Primary, secondary, tertiary and quaternary✓
• B. Primary, secondary and tertiary only
• C. Primary and quaternary only
• D. Quaternary only

Explanation: The correct answer is that primary, secondary, tertiary, and quaternary structures all control the shape of the active site. The primary structure refers to the sequence of amino acids, which is critical for the positioning of the active site residues. The secondary structure involves local folding patterns like alpha-helices and beta-sheets that contribute to the protein's overall shape. The tertiary structure is the overall 3D shape of the single polypeptide chain, which affects the position and orientation of the active site. Finally, the quaternary structure is essential because the enzyme consists of two identical chains, and their interaction helps form the functional enzyme with a properly oriented active site. Other options fail to incorporate all these necessary levels of structure.

Q81. The reflex arc, which is made of two neurons is known as:

• A. Monosynaptic reflex arc✓
• B. Disynaptic reflex arc
• C. Polysynaptic reflex arc
• D. Asynaptic reflex arc

Explanation: The correct answer is the Monosynaptic reflex arc. It consists of only two neurons: a sensory neuron and a motor neuron, with a single synapse between them. This allows for a quick reflex action, such as the knee-jerk reflex. In contrast, the Disynaptic reflex arc involves an additional interneuron, leading to two synapses, and the Polysynaptic reflex arc involves multiple interneurons and synapses, allowing for more complex reflex actions. The Asynaptic reflex arc is not a valid term, as all reflex arcs require at least one synapse to function.

Q82. The life span of RBC is:

• A. 100 days
• B. 110 days
• C. 120 days✓
• D. 130 days

Explanation: This is a standard answer. Lifespan of RBCs is approximately 120 days.This option c suggests that the life span of red blood cells (RBCs) is 100 days. In humans, the average life span of RBCs is indeed around 100-120 days. During this time, RBCs transport oxygen throughout the body before being removed by the spleen and liver.

Q83. What describes a non-specific immune response?

• A. Activation of killer T lymphocytes by infected cells
• B. Cloning of B lymphocytes to form plasma cells
• C. Ingestion of a bacterial cell by a neutrophil✓
• D. Presentation of antigen on the cell surface of macrophages

Explanation: c) Ingestion of a bacterial cell by a neutrophil:This option describes a non-specific immune response. Neutrophils are a type of white blood cell and part of the innate immune system. They are capable of engulfing and destroying pathogens, such as bacteria, through a process called phagocytosis. This is a non-specific response as neutrophils can target a wide range of pathogens without requiring prior exposure.

Q84. Which of the following is found at the end of long bones, in the nose, larynx, and trachea?

• A. Elastic cartilage
• B. Fibrous cartilage
• C. Perichondrium
• D. Hyaline cartilage✓

Explanation: Hyaline cartilage is the most abundant type of cartilage and is found in the nose, ears, trachea, larynx, and smaller respiratory tubes.Fibrocartilage is found in vertebral discs and ligaments.Elastic cartilage is found in the external ear and epiglottis.

Q85. High temperature stops enzyme activity because enzymes:

• A. Dissolve
• B. Ionize
• C. Denature✓
• D. React with substrate

Explanation: Excess heat breaks hydrogen and ionic bonds ---> enzyme loses shape ---> inactive.

Q86. Which of the following ideas was not part of Charles Darwin’s theory of evolution by natural selection?

• A. Organisms produce more off springs than the environment can support
• B. Variation between individuals arises by gene mutation✓
• C. Only those individuals best adapted by environment survive and reproduce
• D. Individuals compete for scarce resources

Explanation: The idea that was not part of Charles Darwin's theory of evolution by natural selection is Option B: Variation between individuals arises by gene mutation. While Darwin acknowledged the existence of variation, he did not have a detailed understanding of the genetic mechanisms behind it, such as gene mutations.

Q87. Evolution of kiwi, hooves of modern horse, webbed feet of duck, and loss of teeth in whale were all explained in detail by:

• A. Lamarck✓
• B. Darwin
• C. Weismann
• D. De Vries

Explanation: Lamarckism is a theory of evolution based on the principle that physical changes in organisms during their lifetime. Examples include evolution of kiwi, foot of modern horse, webbed feet of duck, and loss of teeth in whale.

Q88. Which of the following is NOT TRUE about interferons?

• A. Belong to cytokines
• B. Activate natural killer cells
• C. Activate immune cells
• D. Secrete interleukin✓

Explanation: Interferons (IFNs) are a broad class of cytokines that are part of your natural defenses. They tell your immune system that germs or cancer cells are in your body. And they trigger killer immune cells to fight those invaders. Interferons got their name because they "interfere" with viruses and keep them from multiplying.

Q89. Intrinsic factor secreted by parietal cells of stomach mucosa helps in:

• A. Vitamin B12 absorption✓
• B. Protein digestion
• C. Carbohydrate breakdown
• D. Bowel movement

Explanation: Intrinsic factor plays a crucial role in the transportation and absorption of the vital micronutrient vitamin B12.

Q90. Which of the following statements is true?

• A. Alkali metal hydroxides are stable to heat except LiOH✓
• B. CaOH is a stronger base than NaOH
• C. When NaOH is made the gas released at the cathode is C12
• D. NaOH is named as caustic soda because it reacts with fats to form soap.

Explanation: The normal alkali metal oxides react with water to form hydroxide. The hydroxide (MOH) are colorless, strong alkaline and corrosive compounds. These are soluble in water and dissolve with the evolution of heat.All alkali metal hydroxides are thermally stable except LiOH. On heating, Lithium hydroxide decomposes to form lithium oxide.2LiOH → Li2​O+H2​O

Q91. The substance which conducts electricity by the movement of ions:

• A. Graphite
• B. Copper
• C. Molten NaCl✓
• D. Mercury

Explanation: Carbon atom has 4 electrons in its outer shell. This delocalised electron can move move freely between the carbon layers of graphite and conduct electricity. However, in the solid state, ionic compounds such as sodium chloride have their ions fixed in position and therefore these ions cannot move so solid ionic compounds cannot conduct electricity. However in the molten state, ions in ionic compounds are free to flow and therefore molten sodium chloride can conduct electricity.

Q92. Which class of the compounds is represented by the type formula ROR’?

• A. Esters
• B. Ethers✓
• C. Aldehydes
• D. Ketones

Explanation: A. "Esters" have the general formula R-COO-R'. B. "Ethers" have the general formula R-O-R' where R is the Alkyl group that is variant.C. "Aldehydes" have the general formula R-COH.D. "Ketones" have the general formula R-CO-R.

Q93. The common name for 2-propanone is:

• A. Formaldehyde
• B. Acetone✓
• C. Benzaldehyde
• D. Acetaldehyde

Explanation: 2-Propanone is the systematic IUPAC name for the simplest ketone. Its widely used common name is acetone.

Q94. If a molecule MX3 has zero dipole moment, the sigma bonding orbitals used by M are:

• A. Pure p
• B. sp hybrids
• C. sp2 hybrids✓
• D. sp3 hybrids

Explanation: In order for MX3 molecule to have zero dipole moment, it must have a symmetrical shape which in this case can only be trigonal planar. The bond angle in this case between X-X would be 120o so it should have sp2 hybrids.

Q95. On the hydrogen atom spectrum, a series of spectral lines that fall within the visible region is:

• A. Lymen series
• B. Balmer Series✓
• C. Paschen series
• D. Bracket series
• E. Pfund series

Explanation: Lyman series of hydrogen atom lies in ultraviolet region, Balmer series lies in visible region while Pfund and Paschen series lie in infrared region.

Q96. Identify the correct statement:

• A. Element sodium can be prepared and isolated by electrolyzing an aqueous solution of NaCl
• B. Elemental Na is a strong oxidizing agent
• C. Elemental Na is insoluble in NH3
• D. Elemental Na is easily oxidized✓

Explanation: Good reducing agents include the active metals, such as sodium, magnesium, aluminum, and zinc, which have relatively small ionization energies and low electro-negativities.

Q97. The second and third period contain:

• A. 18 elements each
• B. 32 elements each
• C. 8 elements each✓
• D. 14 elements each

Explanation: Fact.The 2nd-period elements: lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, and neon. The 3rd-period elements: sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, and argon.

Q98. Element X is in group 3 and element Y is in group 6 of the periodic Table. Which of the following is the most likely formula of the compound formed when X and Y react together?

• A. X3Y2
• B. X3Y6
• C. X2Y3✓
• D. None of these

Explanation: Element X will have a valency of +3 while Y will have a valency of -2. Thus the most likely formula of the compound is X2Y3.

Q99. Which class of halogenoalkane can react with alkali by an SN2 mechanism?

• A. Primary and secondary✓
• B. Secondary and tertiary
• C. Primary and tertiary
• D. Primary, secondary and tertiary

Explanation: a) Primary and secondary: This option suggests that both primary and secondary halogenoalkanes can react with alkali by an SN2 (substitution nucleophilic bimolecular) mechanism. In SN2 reactions, the nucleophile attacks the carbon atom bearing the leaving group, resulting in a simultaneous substitution of the leaving group and the nucleophile. Primary and secondary halogenoalkanes are suitable for SN2 reactions because they have a less hindered carbon center, allowing the nucleophile to approach and substitute the leaving group more easily.

Q100. The net enthalpy change in a chemical reaction is same whether it is brought about in two or more different ways in one or several steps. It is known as:

• A. Joule’s law
• B. Law of conservation of energy
• C. Hess’s law✓
• D. Henry's law

Explanation: According to Hess's law, the thermal effects of a reaction depends upon the initial and final conditions of the reacting substances. It does not depend upon the immediate steps.

Q101. Electron affinity decreases down the group due to:

• A. Increase in atomic radius✓
• B. Decrease in atomic radius
• C. Increase in electronegativity
• D. All of the above options are correct

Explanation: Electron affinity decreases from top to bottom within a group. This is caused by the increase in atomic radius.

Q102. It is impossible for two electrons to have same value of spin quantum number in the same orbital, according to:

• A. Hund’s rule
• B. Aufbau principle
• C. Pauli’s exclusion principle✓
• D. All of the above options are correct

Explanation: The Pauli Exclusion Principle states that, in an atom or molecule, no two electrons can have the same four electronic quantum numbers. As an orbital can contain a maximum of only two electrons, the two electrons must have opposing spins.

Q103. Nature of diamond as solid is:

• A. Covalent✓
• B. Ionic
• C. Molecular
• D. Metallic

Explanation: It has a single type of atom and we have discussed above that among similar atoms covalent bonding is seen. Therefore, we can say that the nature of bond in diamonds is covalent.

Q104. Ideal gas equation is:

• A. P = nRT
• B. PV = RT
• C. V = nRTP
• D. PV = nRT✓

Explanation: According to the Ideal Gas equation: The product of Pressure & Volume of a gas bears a constant relation with the product of Universal gas constant, number of moles of gas and temperature. ie. PV = nRT.

Q105. How many moles of CO2 contain 16g of oxygen?

• A. 5 mol
• B. 16 mol
• C. 0.5 mol✓
• D. 2 mol

Explanation: 1 mol of CO2 contains = 32 g O2=1 6 g O2 will be present in = 16/32 = 0.5 mol

Q106. The maximum density of water is at:

• A. 2.98˚C
• B. 3.98 ˚C✓
• C. 4 ˚C
• D. 4.98 ˚C

Explanation: The maximum density of water is at 3.95°C as there are two opposite effects that are in balance. The density of ice is less than liquid water, so it floats. Upon freezing, the ice density decreases by about 9%.

Q107. Homocyclic hydrocarbons are further divided into:

• A. Alicyclic and aromatic✓
• B. Carbocyclic and heterocyclic
• C. Acyclic and heterocyclic
• D. Heterocyclic and aromatic

Explanation: Homocyclic compounds are divided into two compounds. Alicyclic compounds and aromatic compounds.

Q108. Which contains sp2 hybridization?

• A. Methane
• B. Ethane
• C. Alkyne
• D. None of these options are correct✓

Explanation: The hybridization of methane molecules occurs by mixing one orbital with three p orbitals. In ethane (CH3CH3), both carbons are sp3-hybridised. Alkynes undergo sp hybridization.

Q109. Diameter of an atom is in the range of?

• A. 0.2m
• B. 0.2 nm✓
• C. 2 x 10-19nm
• D. 0.2 pm

Explanation: The diameter of an atom is 0.2nm. PTB-Pg 2

Q110. 78g of a hydrocarbon occupies 22.414 dm3 of volume at S.T.P. The empirical formula of the hydrocarbon is CH. The molecular formula of this hydrocarbon is:

• A. C2H4
• B. C6H6✓
• C. C8H8
• D. C4H4

Explanation: Molar mass of CH = 12+1 = 13g Molar mass of the hydrocarbon = 78g as 22.414 dm3 is equal to 1 mol. Molecular formula = n x Empirical formula 78 = n * 13 n = 6 So the molecular formula is 6(CH) = C6H6 i.e. option B.

Q111. Point out the property which is not characteristic of alkali metal:

• A. Low electronegativity
• B. Low melting point
• C. Their ions are isoelectronic with noble gas
• D. High ionization energy✓

Explanation: Alkali metals have low ionization energies due to their larger atomic radii.

Q112. Metals belonging to the same group in the periodic table are:

• A. Magnesium and Sodium
• B. Magnesium and Copper
• C. Magnesium and Barium✓
• D. Magnesium and Potassium

Explanation: Refer to the image below. As we can see in the periodic table, Magnesium and Barium are the only two metals from the options which are in the same group (Group II).

Q113. Magnesiums keep on burning in:

• A. CO2
• B. Magnesium and Copper
• C. N2O
• D. N2 as well as CO2✓

Explanation: When burning magnesium is placed in carbon dioxide it keeps burning with a bright flame. it burns in N2 aswell.

Q114. Example of a nucleophile is:

• A. BF3
• B. AlCl3
• C. SO3
• D. CN✓

Explanation: A nucleophile is a species that donates a pair of electrons to form a covalent bond. Examples of nucleophiles include negatively charged ions (such as CN-, OH-, and NH2-) and neutral molecules with a lone pair of electrons (such as H2O, NH3, and CH3OH). In this case, CN- is a nucleophile.

Q115. In the electrolysis of molten ZnCl2, how much Zn can be deposited at the cathode by the passage of 0.01 ampere for one hour?

• A. 0.002 g
• B. 0.123 g
• C. 0.012 g✓
• D. 0.004 g

Explanation: In this scenario, we first find the total number of charges flown through the apparatus. The formula that we are going to be using is Charge= Ampere x Time. 1 mole of Zn is formed when we have two moles of electrons being added to 1 mole of Zn2+. 1 mole of electrons carries a charge of 96500 coulombs. So, 2 moles of electrons would have a charge of 193000C. To find the moles of Zn deposited, we have the charge passed divided by the charge required to form 1 mole of Zn. Once we have the moles, we multiply them by the molar mass. For a better understanding, please see the attached solution.

Q116. Oxidation of a primary alcohol with PCC (Pyridiniumchlorochromate) gives a/an:

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

Explanation: PCC is a mild oxidizing agent that is selective for the oxidation of primary alcohols. It converts them to aldehydes and is not strong enough to oxidize them further to carboxylic acids.

Q117. Given the bond energy N ≡ N, N - H and H - H bonds are 945, 391, and 436 kJmol-1 respectively, the enthalpy of the reaction N2(g) + 3H2(g) -> 2NH3(g) is;

• A. -93 kJ✓
• B. 102 kJ
• C. 90 kJ
• D. 105 kJ

Explanation: To find the enthalpy change for the reaction N2(g) + 3H2(g) → 2NH3(g), we calculate the total bond energies for both the reactants and products.For the reactants:1 N≡N bond requires 945 kJ3 H-H bonds require 3 x 436 kJ = 1308 kJTotal energy to break bonds in reactants = 945 kJ + 1308 kJ = 2253 kJ.For the products (2 NH3):6 N-H bonds require 6 x 391 kJ = 2346 kJTotal energy released when forming bonds in products = 2346 kJ.Thus, the enthalpy change (ΔH) is:ΔH = Energy of bonds broken - Energy of bonds formed = 2253 kJ - 2346 kJ = -93 kJ.This indicates that the reaction is exothermic, as it releases energy. The other options suggest an endothermic process or incorrect calculations of bond energies.

Q118. A carbonyl compound with molecular formula C5H10O reacted with iodine in an alkaline solution to give a pale yellow precipitate with an antiseptic smell.The carbonyl compound is:

• A. CH3CH2CH3CH3CHO
• B. CH3CH2CH2COCH3✓
• C. CH3CH2CH(CH3)CHO
• D. CH3CH2COCH2CH3

Explanation: b) CH3CH2CH2COCH3:This compound is 2-pentanone, which is a ketone with the molecular formula C5H10O. It is a likely candidate for the carbonyl compound in question. When reacted with iodine in an alkaline solution, it can form a pale yellow precipitate with an antiseptic smell.

Q119. The shape of sulphate ion is:

• A. Hexagonal
• B. Square planar
• C. Trigonal bipyramidal
• D. Tetrahedral✓

Explanation: d) Tetrahedral:The tetrahedral shape refers to a molecule with a central atom surrounded by four ligands, arranged at the corners of a tetrahedron. The sulfate ion (SO4^2-) has a tetrahedral shape since it has four oxygen atoms bonded to a central sulfur atom.

Q120. How many chain isomer can be obtained from alkane C6H14 :

• A. 7
• B. 6
• C. 5✓
• D. 4

Explanation: Hexane (C6H14) has five possible isomers. The isomers are as follows;- Hexane, CH3CH2CH2CH2CH2CH3, a six carbon containing, saturated straight chain alkane. - 2-Methylpentane (Isohexane), CH3CH(CH3)CH2CH2CH3, which is a five carbon containing chain with one methyl branch on the carbon number 2.- 3-Methylpentane, CH3CH2CH(CH2)CH2CH3, is also a five-carbon chain, however the methyl group is attached on Carbon number 3.- 2,3-Dimethylbutane, CH3CH(CH3)CH(CH3)CH3, is a four-carbon -containing chain with a methyl group on carbon number 2 and 3.- 2,2-Dimethylbutane (neohexane), CH3C(CH3)2CH2CH3, is a four-carbon chain with two methyl groups attached on carbon number two.

Q121. The oxidation number of iodine is periodic acid (H5IO6) is:

• A. +7✓
• B. +3
• C. +6
• D. +5

Explanation: a) +7:The oxidation number of iodine in periodic acid (H5IO6) is indeed +7. In periodic acid, iodine is in its highest possible oxidation state. Each oxygen atom in the IO6 group carries an oxidation number of -2, and since the overall charge of the periodic acid molecule is 0, the oxidation number of iodine must be +7 to balance out the negative charges. Explanation:

Q122. Which quantum number tells shape of the orbital?

• A. Magnetic quantum number
• B. Spin quantum number
• C. Azimuthal quantum number✓
• D. Principle quantum number

Explanation: The Azimuthal quantum number (l) describes the shape of the orbital.

Q123. The number of electrons in the p subshell is:

• A. 2
• B. 14
• C. 10
• D. 6✓

Explanation: p subshell has 3 orbit and 1 orbit has maximum 2 electrons.

Q124. Which one of the following has highest bond energy?

• A. HI
• B. HCL
• C. HF✓
• D. HBr

Explanation: HF has the highest bond energy since fluorine is the most electronegative halogen and would bind strongly with an electropositive hydrogen. Therefore the highest bond energy would be of HF.

Q125. The oxidation state of a free element is:

• A. 0✓
• B. >1
• C. -2
• D. -1

Explanation: The oxidation state of an atom in free or uncombined state is zero. For ions or molecular ions, the oxidation state is the net charge.

Q126. A piston in a cylinder is a part of?

• A. System
• B. Surroundings
• C. Boundary✓
• D. None of These

Explanation: The correct answer is Boundary. In thermochemistry, the piston in the cylinder serves as a boundary that separates the system from its surroundings. This boundary allows for changes in volume and work to be performed on or by the system without mixing the substances involved. The other options are incorrect as they misrepresent the role of the piston. The System refers to the actual substances involved in the reaction rather than a physical component like the piston. Surroundings refers to everything external to the system, while None of These is unfounded since the piston clearly has a defined role in thermodynamic terms.

Q127. Fossil fuels are produced due to _?

• A. Fast decomposition of organic matter.
• B. Decomposition of plants.
• C. Decomposition of animals.
• D. Biochemical decomposition of dead organic matter.✓

Explanation: Correct option is D. Fossil fuels are produced due to the biochemical decomposition of dead organic matter. Fossil fuels such as coal, oil, and natural gas are formed from the remains of plants and animals that lived millions of years ago. Over time, as these organic materials were buried under layers of sediment, they underwent a process called diagenesis, which involves the physical and chemical changes associated with the compaction and burial of the organic matter. This process, combined with high pressure and temperature over millions of years, led to the conversion of the organic material into fossil fuels. The biochemical decomposition of dead organic matter is the key process that creates fossil fuels, making them a non-renewable energy resource. d millions of years ago. They create carbon-rich deposits that are extracted and burned for energy. They are non-renewable and currently supply around 80% of the world's energy

Q128. The current in electrolysis is carried through:

• A. Free electrons
• B. Positive ions
• C. Negative ions
• D. Both Options B and C are correct✓

Explanation: In electrolysis, current is carried through the electrolytic solution inside the cell by positive and negative ions using oxidation-reduction reactions. The liquid will continue to conduct electricity only as long as oxidation-reduction reactions occurring at the electrodes continue.

Q129. BH3 has a _ geometry with H-B-H bond angles of 120˚.

• A. Linear
• B. Trigonal planar✓
• C. Tetrahedron
• D. Bent

Explanation: If a molecule has 2 bond pairs and 0 lone pairs then the molecular shape will be linear. e.g. BeCl2If a molecule has 3 bond pairs and 0 lone pairs then the molecular shape will be trigonal planar. BH3 molecule has 3 bond pairs and 0 lone pairs with a bond angle of 120o . Therefore its geometry will be trigonal planar.Hence, B is the correct option.If a molecule has 4 bond pairs and 0 lone pairs then the molecular geometry will be tetrahedral. e.g. CH4If a molecule has 2 bond pairs and 2 lone pairs then they have bent geometry. e.g. H2O.

Q130. Addition of a second electron to a uni-negative ion is always _?

• A. An endothermic process✓
• B. An exothermic process
• C. Neutral process
• D. Energy wasted

Explanation: When a second electron is added to a uni-negative ion, the incoming electron is repelled by the already present negative charge, and energy is absorbed in this process. It is an endothermic process and the absorbed energy is given a positive sign. So, electron affinity is positive.O + e- → O1- EA1 = -141 kJ/molO- + e- → O2- EA2 = +744 kJ/mol.

Q131. Which one of the following is not a secondary alkyl halide?

• A. 2-Chloropropane
• B. 3-Bromobutane
• C. 2,3-Dichloropentane
• D. 2-Chloro-2-methylpentane✓

Explanation: In this compound, the carbon atom bonded to chlorine is attached to only one other carbon atom (the methyl group). Therefore, it is not a secondary alkyl halide. Therefore, option d is correct.

Q132. The strength of London forces depends on the size of:

• A. Electrons.
• B. Electronic cloud.✓
• C. Lone pair on an atom
• D. Poles of atoms

Explanation: The strength of London forces depends upon the size of the electronic cloud of the atom or molecules. When the size of the atom or molecule is big then the dispersion becomes easy and these forces end up being more prominent.

Q133. The evaporation of water is an example of?

• A. Endothermic reaction✓
• B. Exothermic reaction
• C. Spontaneous reaction
• D. Chemical reaction

Explanation: Evaporation of water is an endothermic reaction. During evaporation, water molecules absorb heat from the surroundings and change into vapours and evaporate. That's why the surroundings become cool.

Q134. Why does Cr show 3d54s1 configuration instead of 3d44s2?

• A. Because it is transition element
• B. Because it shows different oxidation states
• C. Because of extra stability of half filled d5 system✓
• D. Because it is typical transition element

Explanation: The correct answer is: Because of the extra stability of the half-filled d5 system. The electron configuration of chromium (Cr) is often represented as 3d5, 4s1 instead of 3d4, 4s2. This is because the configuration of 3d5, 4s1 provides a half-filled d-orbital, which offers extra stability compared to the 3d4, 4s2 configuration.

Q135. A bar magnet has a magnetic moment 200 Am2. The magnet is suspended in a magnetic field of 0.30 NA-1m-1. The torque required to rotate the magnet from its equilibrium position at an angle of 30˚ will be:

• A. 30Nm✓
• B. 3073 Nm
• C. 60Nm
• D. 604Nm

Explanation: τ = MBsinθTorque = 200×0.30×sin30 = 30 Nm.

Q136. A ball is thrown vertically upward with a velocity of 98 m/s. if it takes 10 seconds to reach the highest point then the acceleration of the ball is:

• A. 9.8 m/s²
• B. 980 m/s
• C. 98 m/s²
• D. -9.8 m/s✓

Explanation: Using the first equation of motion: v = u + at final velocity(v) =0m/s initial velocity (u) =98m/s time (t) = 10 acceleration (a) = ? 0=98+10a -98=10a a=-9.8m/s²

Q137. The velocity of a car traveling on a straight road is 36 km/h at an instant of time. Now traveling with uniform acceleration for 10s. The velocity becomes exactly double if the wheel radius of the car is 25cm then which of the following numbers is the closest to the number of revolutions that the wheel makes during these 10s?

• A. 84
• B. 95✓
• C. 126
• D. 135

Explanation: This is the following question:

Q138. A man throws a ball vertically upward in the compartment of an accelerated train. The ball will fall:

• A. ln front of him
• B. In his hand
• C. Behind him✓
• D. Beside him

Explanation: At the time of throwing the ball, it inherits velocity of platform at that moment . And, the horizontal velocity of the ball is constant in the air, because no acceleration in horizontal direction for ball. However, the train is accelerating in forward direction then from frame of train, the ball has horizontal component of acceleration in backward direction.

Q139. A wire of initial length L and radius r is stretched by a length I. Another wire of the same material but with an initial length of 2L and radius 2r is stretched by length 2l. The ratio of the stored elastic energy per unit volume in the first and second wire is:

• A. 1:4
• B. 1:2
• C. 2:1
• D. 1:1✓

Explanation: This is the following solution:

Q140. A wire carries a current out of the page. Which diagram below correctly describes the magnetic field of the wire?

• A. Option A
• B. Option B
• C. Option C
• D. Option D✓
• E. Option E

Explanation: The magnetic field lines form concentric circles around the wire. If you wrap your right hand’s fingers around the wire with your thumb pointing in the direction of the current, then the direction in which the fingers curl will give the direction of the magnetic field. As the current is directed out of the page, then the magnetic field will have a counter clockwise direction. So “D” is the correct answer.

Q141. If an ideal gas has volume V at 27°C and it is heated at constant pressure so that it volume become 1.5V, the value of final temperature is:

• A. 327K
• B. 871K
• C. 177°C✓
• D. 600°C

Explanation: According to Charles Law, V1/T1 = V2/T2(Note: For these questions, always make sure the temperature is in Kelvin)Initial temperature = 27°C For converting temperature in Celcius to Kelvin:273+27 = 300KV/300 = 1.5V/T2T2= (1.5V x 300)/VT2=450KFor converting temperature in Kelvin to Celcius:450-273 = 177°C

Q142. A motorist travelling at 10 ms^-1 can bring his car to rest in a braking distance of 10 m. In what distance could he bring the car to rest from the period of 30 ms^-1 using the same breaking force?

• A. 17 m
• B. 30 m
• C. 52 m
• D. 90 m✓

Explanation: To solve this problem, use the equation of motion: 2as = v² - u².First, determine the acceleration when the initial velocity is 10 m/s and the car stops (v = 0 m/s) over 10 m:2(a)(10) = 0² - 10²20a = -100a = -5 m/s²Next, use the same acceleration for the initial velocity of 30 m/s:2(-5)(s) = 0² - 30²-10s = -900s = 90 mThis calculation shows that the car will take 90 meters to stop from 30 m/s with the same braking force. The other options are incorrect due to miscalculations or misunderstandings of the relationship between velocity and stopping distance.

Q143. Two capacitors C1 (6µF) and C2 (12µF) are in series across a 180 volts D.C supply. Calculate the charges on C1 and C2 respectively.

• A. 120x106 C, -420x106 C
• B. 320x10-6 C, 420x10-6 C
• C. 420x10-6 C, 320x10-6 C
• D. 720x10-6 C, 720x10-6 C✓
• E. 620x10-6 C, 420x10-6 C

Explanation: Charge remains same in series and charges of both capacitors are only same in Option D and so it is the right answer.You can even calculate the charge using this;net capacitance in series:1/C= 1/C1 + 1/C21/C = 1/12 + 1/6 C= 4x10-6 FC=Q/V4x10-6 = Q/180Q= 720 x 10-6 C

Q144. The range of the projectile when launched at an angle of 15 degrees with the horizontal is 15 m. Its range, when launched at 45 degrees with the same speed is:

• A. 30.0 m✓
• B. 1.5 m
• C. 6.0 km
• D. 0.752 km

Explanation: The range of a projectile is given by the formula R = (v0² sin(2θ)) / g, where v0 is the initial speed, θ is the launch angle, and g is the acceleration due to gravity. When θ = 15 degrees, R = 15 m. When the angle is increased to 45 degrees, the formula predicts that the range doubles, as sin(90 degrees) = 1, which maximizes the formula. Therefore, the range is 30 m. The other options provide ranges that are either too small or unrealistic, not aligning with basic projectile motion principles.

Q145. If the mass of the bob of simple pendulum is doubled, its time period is:

• A. One half
• B. Doubled
• C. Remains constant✓
• D. One fourth

Explanation: Time period of a simple pendulum is given by T=1/2π √ (l/g). This means that the time period of a pendulum does not depend on the mass of the bob. So, if the mass of the bob doubled, the time period remains the same.

Q146. The time rate of change of velocity is called:

• A. Force
• B. Acceleration✓
• C. Power
• D. Energy

Explanation: Acceleration is defined as the rate of change of velocity with respect to time. Acceleration is a vector quantity, so it includes both magnitude and direction.

Q147. The slope of displacement-time graph is:

• A. Velocity✓
• B. Displacement
• C. Acceleration
• D. Distance

Explanation: The slope of the displacement-time graph gives the velocity of an object while the slope of the distance-time graph gives the speed of an object.

Q148. An alpha particle is ejected from the nucleus of an atom. Which of the following answers describes the change in the nucleus of the atom?

• A. The atomic number increases by 1, and the mass number remains unchanged.
• B. The atomic number increases by 1, and the mass number decreases by 4.
• C. The atomic number increases by 1, and the mass number increases by 2.
• D. The atomic number increases by 2, and the mass number increases by 4.
• E. The atomic number decreases by 2, and the mass number decreases by 4.✓

Explanation: Alpha emission decreases mass number by 4 and atomic number by 2 for each emitted alpha particle. Gamma emission has no effect on the parent atom. Beta emission causes an increase of proton number by 1.

Q149. A force F = 0.12 N is applied to a spring and the spring elongates by 3 cm. The specific constant of the spring is?

• A. 0.4 Nm-2
• B. 40 Nm-1
• C. 400 Nm-1
• D. 4 Nm-1✓

Explanation: When a spring is stretched/compressed by the application of a force, the relationship between the magnitude of the force applied and the elongation of the spring is given by Hooke's law: F=kx Where F is the magnitude of the spring applied k is the spring constant x is the elongation of the spring relative to its equilibrium position For the spring in this problem, we have: F = 0.12 N (force applied) x = 3 cm = 0.03 m (elongation of the spring) Therefore, we can solve the formula for k to find the spring constant: k=F/x k= 0.12/0.03 k= "4N/m"

Q150. In rotatory motion, angular momentum plays a role which is analogous to that played by _ in linear motion.

• A. Linear velocity
• B. Linear momentum✓
• C. Linear acceleration
• D. Inertia

Explanation: The rotational momentum and "linear momentum both form the same function in a body, they are responsible for keeping the body moving in the direction it is moving, and both quantity the amount of motion (translational tor linear momentum and rotational tor angular momentum) present in the body. Moment of inertia in an analogue to mass in rotational motion. If we want to feel inertia in linear motion we examine the linear acceleration of mass produced by a given force. If acceleration for a given force is more we say that the body has less inertia. If the same force produces less acceleration in another mass then the inertia of the second body for linear motion is large compared to the first body. The expression for this fact is F/m=a. So, mass is the measure of inertia to linear motion.

Q151. Alpha rays are nuclear radiation. They are the same as the _ nuclei.

• A. Hydrogen
• B. Deuterium
• C. Tritium
• D. Helium✓
• E. Lithium

Explanation: Alpha particle has charge of +2e and mass no 4Hydrogen has a charge of +e and mass no 1Deutrium has charge of +e and mass no 2Tritrium has charge of +e and mass no 3Helium has charge of +2e and mass no 4 Lithium has charge of +3e and mass no 7This confirms that alpha rays are same as the Helium Nuclei.

Q152. When two bodies move towards each other with constant speed, the distance between them decreases at the rate 6m/sec. If they move in the same direction, the distance between them increases at the rate of 4 m/sec. Calculate their velocities.

• A. 5 m/sec, 1 m/sec✓
• B. 3 m/sec, 3 m/sec
• C. 6 m/sec, 1 m/sec
• D. 4 m/sec, 2 m/sec

Explanation: Let's name the two unknown speeds as V1 and V2.From the information given,V1+V2 = 6V1 - V2 = 4Solving the equations simultaneously,V1 = 4 + V2Substituiting this in first equation,4 + V2 + V2 = 6 2V2 = 2V2 = 1 m/sV1 = 4 + V2 V1 = 4 + 1V1 = 5 m/s.Option A is the correct answer.

Q153. The path difference for the constructive interference is:

• A. (n-1)λ
• B. (n+1)λ
• C. n λ / 2
• D. 2n λ
• E. n λ✓

Explanation: Option A: (n-1)λ: This is the path difference for destructive interference. When the path difference is one wavelength less than a whole number of wavelengths, the waves will be out of phase and will cancel each other out. Option B: (n+1)λ: This is also the path difference for destructive interference. When the path difference is one wavelength more than a whole number of wavelengths, the waves will be out of phase and will cancel each other out. Option C: nλ/2: This is the path difference for a node. A node is a point where the waves cancel each other out completely. Option D: 2nλ: This is not possible, as the path difference cannot be greater than the wavelength of the wave. Option E: The path difference for constructive interference is nλ, where n is any integer. This means that the difference in the distance traveled by two waves must be a whole number of wavelengths. When this happens, the waves will be in phase and will add together to create a larger wave.

Q154. The light exhibits the phenomena of constructive interference under the situation when it is _ and _.

• A. Monochromatic and in Phase✓
• B. Monochromatic and out of Phase
• C. In phase and non-monochromatic
• D. Out of phase and non-monochromatic

Explanation: Option A: The light exhibits the phenomena of constructive interference under the situation when it is monochromatic and in phase. Monochromatic light means that the light waves have a single wavelength. This is important because constructive interference can only occur if the waves are in phase with each other. When two waves are in phase, they have the same amplitude and the same wavelength. This means that when they overlap, they add together to create a larger wave. Option B: Monochromatic and out of phase: This will not produce constructive interference. Out of phase waves have different amplitudes and/or different wavelengths. When out of phase waves overlap, they cancel each other out. Option C: In phase and non-monochromatic: This will not produce constructive interference. Non-monochromatic light means that the light waves have multiple wavelengths. The different wavelengths of the light will not be in phase with each other, and they will cancel each other out. Option D: Out of phase and non-monochromatic: This will not produce constructive interference. Out of phase waves have different amplitudes and/or different wavelengths. When out of phase waves overlap, they cancel each other out.

Q155. Which row describes the oscillations of two moving particles in a stationary wave that are separated by a distance of half a wavelength?

• A. A
• B. B
• C. C
• D. D✓

Explanation: 1 full wavelength is 2π or 360°, so half wavelength will have a 180° difference or π. Amplitude will be the same as it is the same particle, unless told otherwise. Hence, option D.

Q156. projectile motion, the range of projectile will be maximum at an angle of:

• A. 30 degrees
• B. 45 degrees✓
• C. 80 degrees
• D. 90 degrees

Explanation: The greatest the value of sin of anything can be is 1. This angle will be at 45 degrees.

Q157. Which of the following is not true?

• A. Momentum is quantity of motion
• B. Unit of momentum is N.s
• C. Momentum is not a vector quantity✓
• D. Momentum is product of mass and velocity

Explanation: Momentum is a vector quantity. The direction of an object's momentum vector is in the direction that the object is moving.

Q158. A magnetic needle is placed in a uniform magnetic field and is aligned with the field. The needle is now rotated by an angle of 60 degrees and work done is W. The torque on the magnetic needle at this position is

• A. 2√3 W
• B. √3 W✓
• C. √(3/2) W
• D. √(3/4) W

Explanation: The torque (τ) on a magnetic needle in a uniform magnetic field is given by the formula τ = mB sin(θ), where m is the magnetic moment, B is the magnetic field strength, and θ is the angle between the magnetic moment and the magnetic field. In this case, the needle is rotated by 60 degrees, so sin(60°) = √3/2. Therefore, the torque can be expressed in relation to the work done (W) when the needle aligns with the magnetic field. Since the work done is given as W, at 60 degrees, the correct torque value simplifies to √3 W. The other options are incorrect because they either miscalculate the sine value for the given angle or do not follow the relationship between torque and work accurately.

Q159. In perfect elastic collision

• A. Only momentum is conserved
• B. Only total energy is conserved
• C. Only kinetic energy is conserved
• D. Momentum, kinetic energy, and total energy is conserved✓

Explanation: Kinetic energy and hence momentum is conserved only in elastic collision. The kinetic energy is not conserved in inelastic collisions but the total energy is conserved in all types of collisions.

Q160. Two stones, 10kg and 50kg fall through 80m high cliff. Which stone has greater velocity at bottom? (ignoring air resistance)(g=10ms-2)

• A. 10kg
• B. 50kg
• C. Both have same velocity✓
• D. Cannot be calculated

Explanation: If we neglect air resistance both objects reach the ground at the same time so their velocity will be the same.

Q161. Conversion of heat energy completely into work violates:

• A. Zeroth law of thermodynamics
• B. First law of thermodynamics
• C. Second law of thermodynamics✓
• D. Both, the first and second laws of thermodynamics

Explanation: Conversion of heat energy completely into work implies no loss of energy. Second law of thermodyanmics states that not all heat energy can be converted into work in a cyclic process. Therefore, this statement is exactly oopposite to second law of thermodynamics.

Q162. A frictional piston-cylinder based enclosure contains some amount of gas at a pressure of 400k Pa. Then heat is pressure in a quasi-static process. The piston moves up slowly through a height of 10cm. lf the piston has across section area of 0.3m2,the work done by the gas in the process is:

• A. 6kj
• B. 12kj✓
• C. 75kj
• D. 24kj

Explanation: This is the following solution:

Q163. An electric cell of e.m.f E, is connected across a copper wire of diameter d and length L. The drift velocity of electrons in the wire is v0. If the length of the wire is changed to 2L, the new drift velocity of electrons in the copper wire will be:

• A. V
• B. 2V
• C. V/2✓
• D. V/4

Explanation: At constant voltage, the drift velocity is inversely proportional to the length of the conductor. So If the length of the conductor is doubled, the drift velocity will become half of the original value.

Q164. The resultant of two forces of magnitude F and 2F can be:

• A. Less than F
• B. More than 3F
• C. Equal to √5F when the forces are perpendicular✓
• D. Perpendicular to 2F

Explanation: To find the resultant of two forces, consider both the magnitude and the direction. If two forces are not aligned, their resultant is found using vector addition. The maximum resultant occurs when the forces are in the same direction (3F), and the minimum occurs when they are in opposite directions (F). If the forces are perpendicular, the resultant can be calculated as √(F² + (2F)²), which simplifies to √5F. This makes the correct option the one where the forces are perpendicular, leading to a resultant of √5F.

Q165. How much work is done by force of gravity in pulling a stone of weight 10N from the top of 250m high cliff to the foot of cliff?

• A. 250J
• B. 25J
• C. 2500J✓
• D. 25,000J

Explanation: Potential energy = Mgh Mg (weight) is given as 10N So, 250x10=2500.

Q166. When the speed of your car is halved, by what factor does its kinetic energy decrease?

• A. 1/2
• B. 1/4✓
• C. 1/8
• D. 1/6

Explanation: If the speed is halved (keeping the mass same), the kinetic energy decreases, it becomes one-fourth (since kinetic energy is proportional to the square of velocity).

Q167. Relationship between angular and linear velocity is:

• A. ω= rv
• B. v= rω✓
• C. ω= v/r2
• D. v= ω/r

Explanation: Relation Between Linear Velocity and Angular Velocity |v| = rω, which is the relation between linear and angular velocity.

Q168. Which of the following statement is incorrect:

• A. Photoelectric emission does not occur below the threshold frequency
• B. The photoelectric current increases with the frequency of incident light✓
• C. Threshold frequency depends on the metal used
• D. The emission of photoelectrons is an instantaneous process

Explanation: In photoelectric effect Electrons are emitted instantaneously; the intensity of light determines only their numbers. So, photoelectric current is independent on the frequency of light.

Q169. In a ripple tank 100 waves pass through a certain point in one second. If the wavelength of the wave is 1cm then the speed of the wave will be?

• A. 1 ms-1✓
• B. 2 ms-1
• C. 3 ms-1
• D. 4 ms-1

Explanation: Frequency=100, Wavelength= 1cm = 1/100 = 0.01m.Frequency = Speed/Wavelength(Frequency) (Wavelength) =Speed(100)(0.01)=1m/s.

Q170. Find the resistance if voltage of the circuit is 45 volts and current 30 Amp.

• A. 1.6 ohm
• B. 1.5 ohm✓
• C. 1.7 ohm
• D. 1.8 ohm

Explanation: R = V / ISubstituting the given values, we get:R = 45 V / 30 A = 1.5 ohmTherefore, the resistance of the circuit is 1.5 ohm

Q171. 12,32,72,152 _

• A. 312✓
• B. 325
• C. 515
• D. 613

Explanation: 12+20=3232+40=7272+80=152so 160 should be added in 152152+160=312

Q172. 8, 10, 14, 18, _ , 34, 50 , 66:

• A. 24
• B. 25
• C. 26✓
• D. 27

Explanation: The series progresses as follows: starting from 8, we add 2 to get 10, then add 4 to get 14, again add 4 to get 18. The next step requires adding 8 to 18, resulting in 26. This fits the established pattern of increasing increments: +2, +4, +4, +8. The subsequent number in the series is then 34, followed by 50, and 66, which confirm the sequence's consistency. Options A, B, and D are incorrect as they do not adhere to this increment pattern.

Q173. What letter comes next in the following series? B D G K P

• A. C
• B. E
• C. B
• D. V✓
• E. Q

Explanation: B c DD e f GG h i j KK l m n o PP q r s t u V

Q174. Cup : Coffee :: Bowl : ?

• A. Water
• B. Soup✓
• C. Plate
• D. Spoon

Explanation: The relationship in the pair 'Cup : Coffee' shows that a cup is the vessel typically used for serving coffee. Similarly, in the pair 'Bowl : Soup', a bowl is the vessel commonly used for serving soup. This functional relationship is not shared with the other options: 'Water' is not associated with a bowl, a 'Plate' does not typically hold liquids like soup, and a 'Spoon' is a utensil, not a serving vessel.

Q175. Battery : Power :: Engine : ?

• A. Oil
• B. Motion✓
• C. Car
• D. Fuel

Explanation: The relationship between a battery and power is one of function: a battery provides power. Similarly, an engine results in motion. While oil, car, and fuel are related to an engine, they do not directly describe the primary function or output of an engine. Oil is a lubricant, a car is a vehicle that contains an engine, and fuel is consumed by the engine. Thus, the correct answer is 'Motion', which directly results from the engine's operation.

Q176. Planet : Orbit :: Wheel : ?

• A. Spin
• B. Turn
• C. Rotate
• D. Axle✓

Explanation: The relationship between 'Planet' and 'Orbit' is that of a primary object and its path or essential component for movement. Similarly, a 'Wheel' requires an 'Axle' to function properly, as the axle serves as the central support around which the wheel rotates. The other options describe actions (spin, turn, rotate) rather than a structural relationship.

Q177. Pick the odd word out:

• A. Just
• B. Fair
• C. Equitable
• D. Biased✓

Explanation: The words "just," "fair," and "equitable" are all synonyms related to impartiality and justice. "Biased" is an antonym, meaning to show prejudice for or against something, making it the odd one out.

Q178. Statements: 1. Tanya is older than Eric. 2. Cliff is older than Tanya. 3. Eric is older than Cliff. If the first two statements are true, the third statement is:

• A. True
• B. False✓
• C. Uncertain
• D. None of these

Explanation: If Cliff is older than Tanya, and Tanya is older than Eric, then the age order is Cliff > Tanya > Eric. Therefore, the statement "Eric is older than Cliff" must be false.

Q179. If 7(x-2) = 3x - 2. What is the value of x?

• A. -4
• B. -3
• C. 2
• D. 3✓
• E. 4

Explanation: To solve the equation 7(x-2) = 3x - 2, begin by expanding the left side: 7x - 14 = 3x - 2. Next, move all terms involving x to one side and constant terms to the other: 7x - 3x = -2 + 14. Simplify to get 4x = 12. Divide both sides by 4 to find x = 3.Options A, B, C, and E result in incorrect equations when substituted back into the original equation, hence they are incorrect.