Punjab Mdcat Mock Paper 5 — Solved Past Paper with Answers

Q1. Choose the word most similar in meaning to the given word:Disruption

• A. Comfort
• B. Luxury
• C. Trouble✓
• D. Freedom

Explanation: Disruption means disturbance or problems which interrupt an event, activity, or process. "Trouble" has similar meanings of difficulty or problems. Hence, this is the most suitable option.

Q2. We prefer fruits _ sweets.

• A. Then
• B. On
• C. Over✓
• D. From

Explanation: The correct preposition to use in this case will be “over”. You prefer one thing “over” the other.

Q3. Ahmed _ me for a long time.

• A. Know
• B. Has known✓
• C. Knows
• D. Knew

Explanation: The most appropriate word to fill in the blank would be "has known."The complete sentence would be: "Ahmed has known me for a long time."Using the present perfect tense "has known" indicates that Ahmed developed knowledge or familiarity with the speaker in the past and that this knowledge or familiarity has continued up until the present time.

Q4. Choose the correctly punctuated sentence:

• A. What a fall was there, my countrymen! Long live the king!✓
• B. What a fall was there! My countrymen. Long live the king!
• C. What a fall was there, my countrymen. Long live the king.
• D. What a fall was there, my countrymen, long live the King.

Explanation: There are no conjunctions in the entire statement. Hence, any independent clauses must be separated into different sentences. “Long live the King!” stands as an independent sentence,while “What a fall was there,my countrymen!” can stand as an independent sentence. Moreover since both statements are exclamatory, an exclamation mark should be used to determine their ends. Therefore, Option A is correct.

Q5. Choose the correct option:

• A. “Well no, perhaps not sir”
• B. “Well, no, perhaps not sir”✓
• C. “Well, no perhaps not sir”
• D. “Well no perhaps, not sir”

Explanation: Commas should be used at these places to lay emphasis. The key to solving this question is to read the sentence in your head and then decide at which places a pause should be incorporated.

Q6. Not only the parents but also their son _ for interview.

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

Explanation: Parents are plural but the blank follows the noun 'son' which is singular. Hence "has" instead of "have" is the right option.The sentence refers to an act being done to the noun instead of the son doing something. Hence it will be: ‘been called’ instead of just ‘called’

Q7. Select the option which fits appropriately in the blank:Annie and her brothers _ at school.

• A. Is
• B. Are✓
• C. Are being
• D. Have

Explanation: The correct option that fits appropriately in the blank is:"Annie and her brothers are at school."The subject of the sentence is "Annie and her brothers," which is a plural noun since it refers to multiple individuals. Therefore, the correct verb to use is "are," which agrees with the plural subject. The other options do not match the subject-verb agreement correctly.

Q8. Select the option which fits appropriately in the blank:Dan _ a lot of friends.

• A. Have
• B. Has✓
• C. Is having
• D. Having

Explanation: The correct option that fits appropriately in the blank is:"Dan has a lot of friends."The subject of the sentence is "Dan," which is singular. Therefore, the appropriate verb to use is "has," which agrees with the singular subject in the present tense. The other options do not match the subject-verb agreement correctly. "Have" is used for plural subjects or for the pronouns "you," "we," "they." "Is having" is in the present progressive tense, which is not suitable in this context. "Having" is a present participle, and it does not work as the main verb in this sentence.

Q9. Select the option which fits appropriately in the blank:The gardner will have _ the flowers.

• A. Plucked✓
• B. Pluck
• C. Plucks
• D. None of these options are correct

Explanation: "Plucked" is the correct verb form.The future perfect tense refers to a completed activity in the future.

Q10. The term 'humulin' is used for:

• A. Hydrolytic enzyme
• B. Powerful antibiotic
• C. Human insulin✓
• D. Isoenzyme

Explanation: Human insulin (humulin) is the first therapeutic product produced by means of recombinant technology by Eli Lilly and Co. on July 5, 1983.Humulin's approval marked a significant milestone in the history of biotechnology and pharmaceuticals, paving the way for the development of other recombinant DNA-based products.

Q11. It is adapted to conserve water by over 99.5% reabsorption of glomerular filtrate:

• A. Mammalian body including human
• B. Mammalian kidney including human✓
• C. Mammalian skin including human
• D. Mammalian liver including human

Explanation: The mammalian kidney, including that of humans, is highly adapted to conserve water through the efficient reabsorption of glomerular filtrate.

Q12. 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.

Q13. The introduction of t-­DNA into plants involves:

• A. Exposing the plants to cold for a brief period
• B. Allowing the plant roots to stand in water
• C. Infection of the plant by Agrobacterium tumefaciens✓
• D. Altering the pH of the soil and then heat­ shocking the plants.

Explanation: Ti plasmid (tumor inducing) from the soil bacterium Agrobacterium tumefaciens is effectively used as a vector for gene transfer to plant cells. The part of Ti plasmid transferred into plant cell DNA is called the T­-DNA. This T-­DNA, with desired DNA spliced into it, is inserted into the chromosomes of the host plant where it produces copies of itself, by migrating from one chromosomal position to another at random. Such plant cells are then cultured, induced to multiply, and then differentiate to form plantlets. Transferred into the soil, the plantlets grow into mature plants, carrying the foreign gene, expressing throughout the new plant.

Q14. 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.

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. 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.

Q17. 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.

Q18. 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.

Q19. The first clinical gene therapy was given for treating:

• A. Diabetes mellitus
• B. Chicken pox
• C. Rheumatoid arthritis
• D. Adenosine deaminase deficiency.✓

Explanation: Gene therapy is a collection of methods that allows the correction of a gene defect that has been diagnosed in a child/embryo. Here genes are inserted into a person’s cells and tissues to treat a disease. Correction of a genetic defect involves the delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non­functional gene. The first clinical gene therapy was given in 1990 to a 4- year old girl with adenosine deaminase (ADA) deficiency. This enzyme is very important for the immune system to function. SCID is caused due to defect in the gene for the enzyme adenosine deaminase. In some children, ADA deficiency can be cured by bone marrow transplantation. Here, the isolated gene from bone marrow cells producing ADA is introduced into cells at early embryonic stages; it can be a permanent cure.

Q20. Bacillus thuringiensis forms protein crystals that contain insecticidal protein. This protein:

• A. Binds with epithelial cells in the midgut of the insect pest ultimately killing it✓
• B. Is coded by several genes including the gene cry
• C. Is activated by acid pH of the foregut of the insect pest
• D. Does not kill the carrier bacterium which is itself resistant to this toxin

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.

Q21. The process of RNA interference (RNAi) has been used in the development of plants resistant to:

• A. Nematodes✓
• B. Fungi
• C. Viruses
• D. Insects

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.

Q22. Read the following four statements.(A) The first transgenic buffalo, Rosie, produced milk that was human alpha­ lactalbumin enriched.(B) Restriction enzymes are used in the isolation of DNA from other macromolecules.(C) Downstream processing is one of the steps of rDNA technology.(D) Disarmed pathogen vectors are also used in the transfer of rDNA into the host.Which of the two statements have mistakes?

• A. B and C
• B. C and D
• C. A and C
• D. A and B✓

Explanation: In 1997, the first transgenic cow, Rosie, produced human protein enriched milk. The milk contained the human alpha ­lactalbumin and was nutritionally a more balanced product for human babies than natural cow­milk. Isolation of DNA from other macromolecule is achieved by treating the bacterial cells/plant or animal tissue with enzymes such as lysozyme (bacteria), cellulase (plant cells), chitinase (fungus).

Q23. The external solution having more concentration than the cell sap is known:

• A. Hypertonic solution✓
• B. Hypotonic solution
• C. Isotonic solution
• D. None of these

Explanation: The correct answer is a hypertonic solution. In osmoregulation, when a cell is placed in a hypertonic solution, the external environment has a higher concentration of solutes compared to the inside of the cell. This concentration difference causes water to move out of the cell through osmosis, leading to a decrease in cell volume and potential plasmolysis. Conversely, a hypotonic solution would cause water to move into the cell, and an isotonic solution would result in no net water movement. None of these is incorrect because the correct term for a solution with higher solute concentration than the cell sap is indeed a hypertonic solution.

Q24. 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).

Q25. Homeostasis is the _

• A. Tendency to change with environmental changes
• B. Tendency to resist change and maintain stability✓
• C. Disturbance in regulatory control
• D. Use of plants and animal extracts in homeopathy

Explanation: Homoeostasis is the regulation, by an organism, of the chemical composition of its body fluids and other aspects of its internal environment so that physiological processes can proceed at optimum rates. It involves monitoring changes in the external and internal environment by means of receptors and adjusting the composition of the body fluids accordingly; excretion and osmoregulation are important in this process. Example of homeostatic regulation are the maintenance of the acid-base balance and body temperature.

Q26. Which pair is correct?

• A. Sweat – Temperature regulation✓
• B. Saliva – Sense of taste
• C. Sebum – Sexual attraction
• D. Humerus – Hindleg

Explanation: Sweat is secreted by sweat glands of skin and helps in regulating body temperature. Saliva is secreted by salivary glands and helps in digestion (carbohydrate digestion). Sebum is the waxy secretion secreted by sebaceous glands. Sebum is a fatty mildly antiseptic material that protects, lubricates, and waterproofs the skin and hair and helps prevent desiccation. Humerus is the long bone of the upper arm. It articulates with the scapula at the glenoid cavity and with the ulna and radius at the elbow.

Q27. What is correct about myoglobin?

• A. It is an iron-containing protein pigment
• B. It is found in muscle fibers
• C. It stores oxygen
• D. All of these✓

Explanation: Myoglobin is indeed an iron-containing protein pigment, which is what gives muscle tissues their reddish color. It is found in muscle fibers, where it plays a vital role in storing oxygen. This oxygen storage is crucial for muscle function, as it allows for sustained energy production during muscle contraction. Each of the individual options describes a true characteristic of myoglobin, making 'All of these' the correct choice.

Q28. Thick waxy & leathery cuticle around leaves is present in which of the following?

• A. Hydrophytes
• B. Mesophytes
• C. Halophytes
• D. Xerophytes✓

Explanation: The cuticle is a protective layer on the surface of leaves and other aerial plant parts, composed of cutin, a waxy substance. In xerophytes, the cuticle is thicker and often covered with epicuticular wax, forming a waterproof barrier. This adaptation serves several important functions to help the plant conserve water and prevent excessive water loss in arid conditions. Hence option D is correct.

Q29. A pair of Kidneys consists of _ of functional units.

• A. Million
• B. Billion
• C. Millions✓
• D. Billions

Explanation: Each kidney contains approximately 1 to 1.5 million nephrons, making the total for a pair of kidneys several million nephrons. These are the functional units responsible for filtering blood and maintaining homeostasis.

Q30. The salts are precipitated out during _ and accumulate later to form stone.

• A. Urea formation
• B. Urination
• C. Urine formation✓
• D. Defecation

Explanation: Urine formation involves the filtration of blood in the kidneys, followed by the reabsorption of essential substances and the excretion of waste products, including dissolved salts. In certain conditions, such as when the concentration of salts exceeds the solubility limit, these salts can precipitate out of the urine and accumulate to form stones. Various factors, including dehydration, high concentrations of specific substances (such as calcium or uric acid), and imbalances in the urine pH, can contribute to the formation of stones during urine formation.

Q31. Which chamber has the thickest walls in the heart?

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

Explanation: Left ventricle pumps blood into systemic circulation and requires thick muscular walls to generate high pressure.

Q32. The enzymes required for the Krebs cycle are found in _.

• A. F1 particles
• B. Lysosomes
• C. Cytoplasm
• D. Matrix✓

Explanation: The Krebs cycle enzymes are membrane proteins found within the matrix of the mitochondria except for succinate dehydrogenase which is an integral membrane protein locked to the inner mitochondrial membrane.F1 particle is found in the matrix of mitochondria and is found attached to the cristae. It plays a very important role in the production of ATP molecules as it contains an enzyme called ATPaseA lysosome is a membrane-bound cell organelle that contains digestive enzymes.The cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane.

Q33. Cell-mediated immune response is given by:

• A. T-lymphocytes✓
• B. B lymphocytes
• C. Neutrophils
• D. Macrophages

Explanation: Cell-mediated immunity is an immune response that does not involve antibodies. Rather, cell-mediated immunity is the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen. Humoral immunity is also called antibody-mediated immunity. With assistance from helper T cells, B cells will differentiate into plasma B cells that can produce antibodies against a specific antigen. The humoral immune system deals with antigens from pathogens that are freely circulating, or outside the infected cells. Antibodies produced by the B cells will bind to antigens, neutralizing them, or causing lysis (dissolution or destruction of cells by a lysin) or phagocytosis.

Q34. During breathing, air from pharynx enters to:

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

Explanation: When you inhale through your nose or mouth, air travels down your pharynx (back of your throat), passes through your larynx (voice box) and into your trachea (windpipe). Your trachea is divided into two air passages called bronchial tubes. One bronchial tube leads to your left lung, the other to your right lung.

Q35. The type of carbohydrate which has high molecular weight and is sparingly soluble in water is:

• A. Monosaccharides
• B. Disaccharides
• C. Polysaccharides✓
• D. Maltose

Explanation: Polysaccharides are polymeric carbohydrate molecules composed of long chains of monosaccharide units bound together by glycosidic bonds. They occur as components of high molecular weight compounds significantly less soluble in water due to the absence of hydrogen bonds.

Q36. Among the following, which acid is an unsaturated acid:

• A. Butyric Acid
• B. Oleic Acid✓
• C. Palmitic Acid
• D. Both Oleic Acid and Palmitic Acid

Explanation: •A saturated fatty acid is one that lacks double bonds. Animal fat is commonly composed of saturated fatty acids. They are solid at room temperature.•Unsaturated fatty acid is one that has one or more double bonds in them. They are commonly found in plants and exist in liquid form at room temperature. Oleic acid has a double bond between C9 and C10, making it unsaturated.

Q37. Backbone of amino acids comprises of

• A. R group
• B. Amino group
• C. Peptide bond
• D. Carboxylic group
• E. A,B and D✓

Explanation: Amino acids are molecules that combine to form proteins.Each amino acid contains an amino group, a carboxylic group, an R group, and a hydrogen atom which is attached to the central alpha carbon.All of them form the basic skeleton of amino acids.

Q38. Which of the following holds the alpha helix of protein in its place:

• A. R group
• B. Disulfide bond
• C. Amino group
• D. Hydrogen bond✓

Explanation: The α-helix is a right-handed helix with the peptide bonds present on the inside and the side chains extending outward. It is stabilized by the regular formation of hydrogen bonds parallel to the axis of the helix; they are formed between the amino and carbonyl groups of every fourth peptide bond.

Q39. The simplest independent unit of life is known as:

• A. Bacterial colony
• B. Cell✓
• C. Chloroplast
• D. DNA

Explanation: The cell is the simplest entity that can exist as an independent unit of life. Every known living organism is either a single cell or an ensemble of a few to many cells.

Q40. The process by which unwanted structures within the cell are engulfed and digested within the lysosome is known as:

• A. Endocytosis
• B. Exocytosis
• C. Hydrolysis
• D. Autophagy✓

Explanation: Autophagy is a self-degradative process where the cell isolates damaged organelles or proteins in autophagosomes. These structures then fuse with lysosomes for breakdown and recycling. It helps maintain cellular balance and prevents accumulation of harmful components.

Q41. The plants having foreign DNA incorporated into their cells are called:

• A. Clonal plants
• B. Transgenic plants✓
• C. Biotech plants
• D. Tissue cultured plants

Explanation: The term transgenic indicates an organism that contains genetic material from a foreign source. Transgenic plants are plants that have had foreign DNA incorporated into their cells through genetic engineering techniques.

Q42. The production of genetically identical copies of organisms by asexual reproduction is called:

• A. Genetic engineering
• B. Integrated disease management
• C. Hydroponic culture technique
• D. Cloning✓

Explanation: The correct answer is Cloning. Cloning is a form of asexual reproduction that results in the creation of an organism genetically identical to the original. Unlike genetic engineering, which modifies genes, or hydroponics, which is a cultivation method, cloning naturally replicates an organism's genetic material. Integrated disease management is unrelated to reproduction.

Q43. The model of plasma membrane suggests that proteins are embedded in lipid bilayer.

• A. Unit membrane
• B. Fluid mosaic✓
• C. Permeable
• D. Ultracentrifuge

Explanation: The correct answer is the 'Fluid Mosaic' model, which describes the plasma membrane as a flexible and dynamic structure with proteins embedded within the phospholipid bilayer. This model accounts for the lateral movement of proteins, contributing to the membrane's fluidity and mosaic-like appearance. The 'Unit membrane' model fails to capture this dynamic nature. 'Permeable' is a property of membranes, not a model, and 'Ultracentrifuge' is a tool used in laboratory processes, not related to membrane structure.

Q44. Lipid metabolism is the function of:

• A. Ribosomes
• B. Sarcoplasmic reticulum
• C. Rough Endoplasmic Reticulum (RER)
• D. Smooth Endoplasmic Reticulum (SER)✓

Explanation: The Smooth Endoplasmic Reticulum (SER) is responsible for lipid metabolism, including the synthesis of lipids and detoxification processes.

Q45. In _ response, β-cells produce plasma cells that synthesize antibodies and release them in blood plasma and tissue fluid.

• A. Cell-Mediated
• B. Hormonal
• C. Humoral✓
• D. Phototactic

Explanation: This option is the correct response in the given context. Humoral response refers to the immune response involving the production of antibodies by plasma cells. In this context, β-cells are producing plasma cells that synthesize antibodies and release them into the blood plasma and tissue fluid. This accurately describes the process mentioned in the sentence.

Q46. Passive immunity is used against:

• A. Malaria
• B. Dengue
• C. Thypoid
• D. Tetanus✓

Explanation: The method of passive immunization is used to combat active infections of tetanus, infectious hepatitis, rabies, snake bite venom, etc. Passive immunization is the transfer of antibodies from one person or animal to another, providing immediate but temporary protection against a specific disease. Unlike active immunization, it does not require the recipient's own immune system to create antibodies. This can happen naturally, such as when a newborn receives antibodies from its mother.

Q47. What is the subunit of DNA:

• A. Phosphoric Acid
• B. Base
• C. Nucleotide✓
• D. Sugar

Explanation: A nucleotide is the basic building block of nucleic acids(DNA and RNA).•It is composed of pentose sugar,phosphate and a nitrogenous base.•The four nitrogenous bases in DNA are Adenine,Guanine,Cytosine and Thymine.Options A,B and D are incorrect because all of them are subunits of the nucleotide itself,not DNA.

Q48. Enzymes have what effect on the end-product?

• A. They alter the product
• B. The nature of the product is completely changed
• C. No effect✓
• D. The end product is not obtained

Explanation: Enzymes are biocatalysts that speed up chemical reactions by lowering activation energy. Due to this, the products are formed at a faster rate. But enzymes only affect the rate of reaction without being used up, they can't alter the structure of the final product. Options A, B, and D are incorrect because enzymes function as catalysts only in biochemical reactions.

Q49. Book lungs are present in arthropods for exchange of gases in class:

• A. Crustacea
• B. Insecta
• C. Myriapoda
• D. Arachnida✓

Explanation: Respiration in class arachnida is by gills or special structures called book lungs.

Q50. The type of respiration that involves the step-by-step breakdown of carbon chain molecules in the cell is called

• A. External respiration
• B. Pulmonary respiration
• C. Cellular respiration✓
• D. Cutaneous respiration

Explanation: The correct answer is cellular respiration. This process involves the breakdown of carbon chain molecules, such as glucose, within cells to produce ATP, the energy currency of the cell. The breakdown occurs in several stages, including glycolysis, the citric acid cycle, and oxidative phosphorylation. External respiration and pulmonary respiration refer to the exchange of gases at the respiratory system level, not at the cellular level. Cutaneous respiration involves gas exchange through the skin and is unrelated to the cellular metabolic processes of energy conversion.

Q51. End products of yeast fermentation, bacterial fermentation, and anaerobic respiration are:

• A. Ethyl alcohol, lactic acid, and carbon dioxide✓
• B. Ethyl alcohol, lactic acid, carbon dioxide, and water
• C. Glucose, oxygen, and water
• D. Pyruvic acid, carbon dioxide, and oxygen

Explanation: The correct end products of yeast fermentation, bacterial fermentation, and anaerobic respiration are ethyl alcohol, lactic acid, and carbon dioxide. These products result from energy-yielding processes that occur in the absence of oxygen, allowing organisms to survive under anaerobic conditions.

Q52. In human beings, what is the function of amylase in digestion?

• A. Digestion of triglycerides
• B. Digestion of lipids
• C. Digestion of all types of food
• D. Digestion of carbohydrates✓

Explanation: Option [A] Gastric Lipase breaks down fats in the stomach.Option [B] Lipase breaks down Lipids into fatty acids and glycerol.Option[C] Enzymes are specific for each substrate. Different enzymes are required for the breakdown of different types of food.Option [D] Amylase is the enzyme that breaks down starch[type of carbohydrate]into sugar.

Q53. Where is the ileocolic sphincter located in your body?

• A. At the junction of esophagus and stomach
• B. At the junction of stomach and small intestine
• C. At the junction of ileum and large intestine✓
• D. At the junction of small intestine and large intestine

Explanation: Option[A] cardiac sphincter is present at the junction of esophagus and stomach.Option[B] pyloric sphincter is present at the junction of the stomach and small intestine.Option [C] ileocolic sphincter is located at the junction of the ileum and the first portion of the colon of the large intestine.Option[D] specific positions of intestines are not described in this option.

Q54. The term which is employed to the loss of appetite due to fear of becoming obese is:

• A. Obesity
• B. Anorexia nervosa✓
• C. Dyspepsia
• D. Bulimia nervosa

Explanation: Option[a] Obesity is defined as the accumulation of abnormal or excessive fat that may impair health.Option [b] Anorexia nervosa is an eating disorder characterized by an abnormally low body weight and intense fear of gaining weight.Option [c] Dyspepsia means indigestion, which refers to discomfort or pain that occurs in the upper abdomen often after eating or drinking.Option [d] Bulimia is an eating disorder characterized by uncontrolled episodes of overeating(bingeing).

Q55. Centrioles are made up of _ microtubules:

• A. 9
• B. 27✓
• C. 3
• D. 12

Explanation: Centrioles are key cellular structures involved in cell division, found in animal cells. Structurally, each centriole is made up of nine sets of microtubule triplets, arranged in a cylindrical form. Each triplet contains three microtubules, so when you multiply the nine triplets by the three microtubules per triplet, you get a total of 27 microtubules forming the centriole. Therefore, Option B (27) is the correct answer. Option A (9) incorrectly considers only the number of triplet groups, Option C (3) focuses on the individual microtubules within a triplet rather than the entire structure, and Option D (12) is unrelated to the microtubule count in centrioles.

Q56. The use of living organisms in industry for the production of useful products is known as:

• A. Parasitology
• B. Biochemistry
• C. Biotechnology✓
• D. Molecular biology

Explanation: The exploitation of biological process for industrial and other purposes, especially the genetic manipulation of microorganisms for the production of useful products.

Q57. Treatment by using attenuated culture of bacteria is called _:

• A. Chemotherapy
• B. Sterilization
• C. Antisepsis
• D. Vaccination✓

Explanation: The correct answer is 'Vaccination.' Vaccination involves introducing an attenuated (weakened) or inactivated form of a pathogen to stimulate the immune system to build immunity against the disease without causing illness. This method is distinct from chemotherapy, sterilization, or antisepsis, which do not involve the use of attenuated cultures to invoke an immune response.

Q58. The major cause of hepatitis B is _.

• A. Blood transfusion✓
• B. Blood clotting
• C. Absence of fibrinogen
• D. Contaminated soil

Explanation: Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus (HBV). It is a major global health problem. Hepatitis B is spread when blood, semen, or other body fluids from a person infected with the virus enter the body of someone who is not infected. Hepatitis B is primarily transmitted through contact with infected blood or other body fluids through blood transfusion.

Q59. During animal cell division, the spindle fibres are formed from:

• A. Mitochondria
• B. Centrioles✓
• C. Ribosomes
• D. Lysosomes

Explanation: At the beginning of the nuclear division, two wheel-shaped protein structures called centrioles position themselves at opposite ends of the cell forming cell poles. Long protein fibers called microtubules extend from the centrioles in all possible directions, forming what is called a spindle.

Q60. Which component of the cell is concerned with cell secretions?

• A. Plasma membrane
• B. Golgi complex✓
• C. Cytoskeleton
• D. Mitochondria

Explanation: The Golgi complex is the correct answer because it is the organelle responsible for modifying, sorting, and packaging proteins and lipids that are either secreted from the cell or sent to other locations. Proteins synthesized in the rough endoplasmic reticulum (RER) are transported to the Golgi complex for further processing. Once processed, these proteins are packaged into vesicles for secretion. The other options are not primarily involved in cell secretions: the plasma membrane regulates transport and communication, the cytoskeleton provides structural support, and mitochondria are involved in energy production.

Q61. During which period of interphase (cell cycle) DNA is synthesized?

• A. G1
• B. G2
• C. S✓
• D. G0

Explanation: The S phase of a cell cycle occurs during interphase, before mitosis or meiosis, and is responsible for the synthesis or replication of DNA. In this way, the genetic material of a cell is doubled before it enters mitosis or meiosis, allowing there to be enough DNA to be split into daughter cells

Q62. The soluble part of the cytoplasm or fluid that remains when all organelles are removed is known as:

• A. Solution
• B. Gelatin material
• C. Cytoskeleton
• D. Cytosol✓

Explanation: The correct answer is Cytosol. The cytosol is the aqueous component of the cytoplasm, containing dissolved ions, small molecules, and proteins, where cellular processes occur. The other options are incorrect: a 'Solution' is a general term for a mixture of solutes and solvents, 'Gelatin material' is a protein substance unrelated to cell structure, and the 'Cytoskeleton' is a network of fibers providing structural support, not a fluid component.

Q63. The outer membrane of the nuclear envelope is at places continuous with the:

• A. Golgi Apparatus
• B. Endoplasmic Reticulum✓
• C. Lysosomes
• D. Peroxisomes

Explanation: The outer nuclear membrane is continuous with the endoplasmic reticulum, so the space between the inner and outer nuclear membranes is directly connected with the lumen of the endoplasmic reticulum.

Q64. _ is most abundant carbohydrate in nature.

• A. Waxes
• B. Glycerol
• C. Starch
• D. Cellulose✓

Explanation: Cellulose is the most abundant carbohydrate in nature due to its role as a structural component in the cell walls of plants. It is a polymer made of glucose molecules linked together in a specific configuration, giving plants their rigidity and form. The vast quantity of plant biomass on Earth makes cellulose the most prevalent carbohydrate. Other options, such as waxes and glycerol, are not carbohydrates, and starch, though abundant, primarily acts as an energy storage molecule rather than a structural component.

Q65. Amino acid in which the R-group is hydrogen is:

• A. Glycine✓
• B. Alanine
• C. Leucine
• D. Valine

Explanation: The correct answer is Glycine. Its R-group is a single hydrogen atom, making it the smallest and simplest of all the amino acids. This simplicity allows glycine to fit into tight spaces within protein structures, making it versatile in protein formation. Other amino acids such as Alanine, Leucine, and Valine have more complex R-groups, which include various carbon chains and branches. These differences in R-group composition significantly affect the properties and functions of the amino acids.

Q66. The most critical phase of mitosis which ensures equal distribution of chromatids in the daughter cells is:

• A. Prophase
• B. Metaphase
• C. Anaphase✓
• D. Telophase

Explanation: The third stage of cell division, between metaphase and telophase, during which the chromosomes move away from one another to opposite poles of the spindle.

Q67. The intake of liquid materials across the cell membrane is:

• A. Phagocytosis
• B. Endocytosis
• C. Pinocytosis✓
• D. Exocytosis

Explanation: Pinocytosis (“pino” means “to drink”) is a process by which the cell takes in the fluids along with dissolved small molecules. In this process, the cell membrane folds and creates small pockets and captures the cellular fluid and dissolved substances.

Q68. Which one of the following is the site of oxidative phosphorylation in mitochondria?

• A. Cristae✓
• B. Matrix
• C. Outer membrane
• D. Ribosomes

Explanation: The site of oxidative phosphorylation in mitochondria is the inner mitochondrial membrane. While the inner mitochondrial membrane is the primary site of oxidative phosphorylation, it is essential to mention that the specific structures within the inner membrane called cristae play a crucial role in this process. Cristae are the infoldings or protrusions of the inner mitochondrial membrane, and they significantly increase the surface area available for the various proteins involved in oxidative phosphorylation. Within the inner mitochondrial membrane, there is a series of protein complexes collectively known as the electron transport chain (ETC). This is where the transfer of electrons takes place, and the energy released during this process is used to pump protons across the inner mitochondrial membrane, creating a proton gradient. The enzyme ATP synthase, also located in the inner mitochondrial membrane, utilizes the energy from the proton gradient to synthesize ATP from ADP and inorganic phosphate. This entire process of electron transport and ATP synthesis is referred to as oxidative phosphorylation.

Q69. Organelle involved in the synthesis of ATP is

• A. Ribosome
• B. Mitochondria✓
• C. Nucleus
• D. Centriole

Explanation: The classic role of mitochondria is oxidative phosphorylation, which generates ATP by utilizing the energy released during the oxidation of the food we eat. ATP is used in turn as the primary energy source for most biochemical and physiological processes, such as growth, movement, and homeostasis.

Q70. If the genetic code is made up of three nucleotides, then total possible genetic codes will be:

• A. 4
• B. 20
• C. 64✓
• D. 61

Explanation: Each group of three nucleotides encodes an amino acid. The total number of genetic codes can be found by 4^3 = 64, where 4 is the total number of nucleotide bases and 3 is the number of bases that can be in one genetic code.

Q71. In translation, the terminating codon is:

• A. GUA
• B. UAA✓
• C. UUG
• D. AGU

Explanation: UAA, UAG, and UGA are stop codons. They do not code for any amino acid, instead signal termination of translation.

Q72. The competitive inhibitors have structural similarity with:

• A. Active site
• B. Binding site
• C. Substrate✓
• D. Coenzyme

Explanation: The competitive inhibitor has structural similarity with the substrate, hence it interferes with the substrate binding to the enzyme molecule.

Q73. A cofactor tightly bound to the enzyme on the permanent basis is called:

• A. Activator
• B. Coenzyme
• C. Prosthetic group✓
• D. Apo-enzyme

Explanation: Prosthetic groups are cofactors very tightly bound to the inactive enzyme (called apoenzyme), even covalently in some cases. Examples of them are the biotin and heme groups, cytochrome C, flavin mononucleotide, and FAD.

Q74. The ability to distinguish between two separate points/objects is:

• A. Magnification
• B. Fractionation
• C. Centrifugation
• D. Resolution✓

Explanation: The correct answer is Resolution. Resolution is a key concept in microscopy and imaging, as it defines the ability to distinguish between two closely positioned objects as separate entities. This clarity is essential for detailed analysis in cell biology.While Magnification increases the size of the image, it does not enhance clarity or detail necessary for resolving two close points. Fractionation and Centrifugation are techniques related to separating components of mixtures based on size or density, and do not pertain to the optical resolution of images.

Q75. They serve as a scaffold for formation of higher order chromatin structure:

• A. Nucleosome✓
• B. Nucleus
• C. Chromosomes
• D. Histones

Explanation: Nucleosomes are the basic units of DNA packaging and serve as a scaffold for the formation of higher-order chromatin structures. They consist of DNA wrapped around histone proteins, allowing the DNA to be compacted efficiently within the nucleus. While histones are essential for nucleosome formation, they do not act as a scaffold themselves. The nucleus is the organelle that contains the DNA but does not directly influence the chromatin structure. Chromosomes are the end result of further condensation of chromatin, representing a more complex level of organization, but they do not serve as the starting scaffold for chromatin formation.

Q76. Which one of the following acts as functional unit of lungs in man?

• A. Air sac✓
• B. Trachea
• C. Larynx
• D. Bronchioles

Explanation: Option [a] Air sacs, and alveoli are present at the end of bronchioles in lungs where lungs and blood exchange oxygen and carbon dioxide during inhalation and exhalationOption[b] The Larynx(voice box) contains vocal cords not the part of the lungsOption[c] Trachea that connects the larynx to the lungs. Acts as a passage of air into the lungs.( not the part of the lungs)Option[d] Bronchioles are the smaller branches of the bronchi that enter each lung. Bronchioles give rise to alveoli (air sacs)

Q77. Expiration in human beings is carried out by:

• A. Contraction of lungs
• B. Contraction of intercostal membrane
• C. Relaxation of intercostal and diaphragm muscles✓
• D. Contraction of diaphragm muscles

Explanation: Option [a] Lungs do not contractOption[b] Internal intercostal muscles contractOption [c] During expiration External intercostal muscles relax and internal intercostal muscles contract bringing the rib cage down to its normal position, muscles of the diaphragm Also relax with the chest cavity also reducedOption [d] Diaphragm muscles relax during expiration, contraction of the diaphragm does not occur.

Q78. Granulocytes or white blood cells are produced in:

• A. Lymph nodes
• B. Red bone marrow✓
• C. Tonsils
• D. Spleen

Explanation: Option[a] Lymph nodes don’t have a role in the production of WBC, they filter substances that travel through the lymphatic fluid.Option [b] Bone marrow makes stem cells, which then produce RBC, WBC and plateletsOption[c] The main function of tonsils is fighting infection, they contain a lot of WBC but do not produce them.Option[d] Spleen controls the levels of blood cells including WBC, RBC and platelets, it removes old or damaged RBC whereas WBC are destroyed in the lymphatic system.

Q79. The flow of lymph in lymphatic vessels is maintained by:

• A. Heart, activity of smooth muscles and valves
• B. Activity of skeletal muscles, heart and breathing movements
• C. Breathing movements, activity of skeletal muscles and valves✓
• D. Exercise, breathing movements and heart

Explanation: Option[a] heart has no role in lymph flowOption[b] Heart has no role in lymphOption [c] All mentioned factors affect the flow of lymph in lymphatic vessels i.e. deep breathing helps the flow of the lymph fluid through the body, movement of skeletal muscle increases the lymph flow and valves function to bias lymph flow back towards the heart.Option[d] Heart and exercise play no role in lymph flow

Q80. The central metabolic station and clearing house of a body is:

• A. Liver✓
• B. Kidney
• C. Nephron
• D. Glomerulus

Explanation: Option [a] Liver plays a central role in all metabolic processes in the body. Responsible for the metabolism of fats, proteins, and carbohydrates. It is also involved in detoxification [as it filters all of the blood and breaks down poisonous substances such as alcohol and drugsOption[b] The Kidney is the main excretory organ and is involved in the formation of urine to excrete all the waste products out of the body via urineOption[c] Nephron is the functional unit of the kidney involved in the formation of urineOption[d] Glomerulus is a network of small blood vessels in each nephron enclosed in a sac called Bowman’s Capsule

Q81. Which of the following is purine:

• A. Guanine✓
• B. Cytosine
• C. Thymine
• D. Uracil

Explanation: Guanine is a purine base, which has a double-ring structure, distinguishing it from pyrimidines that have a single-ring structure. Guanine is one of the main nitrogenous bases found in DNA and RNA and pairs with cytosine. The other options, cytosine, thymine, and uracil are all pyrimidines, not purines. Cytosine pairs with guanine, thymine pairs with adenine in DNA, and uracil pairs with adenine in RNA, replacing thymine.

Q82. Optimum pH value for the working of pancreatic lipase is:

• A. 4.50
• B. 7.60
• C. 2.00
• D. 9.00✓

Explanation: The optimum pH for pancreatic lipase is 9.00, which is suitable for its activity in the alkaline environment of the small intestine. Other enzymes have different optimum pH levels depending on where they function: pepsin works best at pH 2.00, reflecting the acidic conditions of the stomach; sucrase functions optimally at pH 4.50; and catalase, which breaks down hydrogen peroxide in cells, has an optimum pH of 7.60.

Q83. Malate is oxidized by _ to oxaloacetate in Krebs’s Cycle.

• A. ATP
• B. NADP
• C. NAD✓
• D. FAD

Explanation: NAD (nicotinamide adenine dinucleotide) is involved in the oxidation of malate to oxaloacetate in the Krebs's Cycle. NAD acts as a coenzyme that accepts hydrogen atoms (H+) and electrons (e-) during the redox reactions in cellular respiration, including the Krebs's Cycle.

Q84. What is the percentage of lipids in the chemical composition of plasma membrane?

• A. 60-80%
• B. 20-40%✓
• C. 40-80%
• D. 20-60%

Explanation: The plasma membrane is the outermost covering of an animal cell. Cell membrane is composed of lipids and proteins;60-80% are proteins, while 20-40% are lipids.

Q85. A complex network of channels extending from plasma membrane to nuclear membrane:

• A. Mitochondria
• B. Lysosomes
• C. Endoplasmic reticulum✓
• D. Golgi Apparatus

Explanation: The endoplasmic reticulum is a continuous membrane system that forms a series of flattened sacs within the cytoplasm of eukaryotic cells and serves multiple functions including the synthesis, folding, modification, and transport of lipids and proteins.

Q86. The group of ribosomes joined by mRNA is called as:

• A. Monosome
• B. Polysomes✓
• C. Polypeptide
• D. Lysosome

Explanation: Polysome is defined as the cluster of ribosomes held together by a strand of mRNA that each of them is translating.•Polysomes/Polyribosomes can be found in three forms: free, cytoskeletal-bound, and membrane-bound.

Q87. Which organelle has two subunits?

• A. Endoplasmic reticulum
• B. Ribosomes✓
• C. Nucleus
• D. Plastids

Explanation: Ribosomes are made of proteins and ribonucleic acid. Ribosomes consist of two major components: the small and large ribosomal subunits. The tinier subunit is the place the mRNA binds and decodes, whereas the bigger subunit is the place the amino acids are included.

Q88. A condition called Goose pimples, are caused by:

• A. Overcooled body✓
• B. Bacteria
• C. Environmental changes
• D. Pollution

Explanation: Option A is correct.The hairs in mammals act as insulating organs and reduce heat loss. Thus the heat is retained in the body to a certain extent. To increase the effect of insulation, the hairs are erected. This occurs involuntarily when the body is over-cooled. In humans, it produces Goose pimples.

Q89. Piriformis syndrome is associated with which of the following disorder:

• A. Arthritis
• B. Sciatica✓
• C. Spondylosis
• D. Disc slip

Explanation: Piriformis syndrome is a condition where the piriformis muscle in the buttocks compresses the sciatic nerve, leading to sciatica symptoms such as pain, numbness, and tingling in the lower limbs. While a slipped disc can also cause sciatica, piriformis syndrome is specifically related to muscle compression rather than disc issues. Arthritis and spondylosis, on the other hand, are primarily joint and spinal disorders that do not typically involve the piriformis muscle or cause sciatica directly.

Q90. It is an endoparasite of humans, cattle and pig that completes its life cycle in two hosts:

• A. Stingray
• B. Liver fluke (Fasciola)✓
• C. Aurelia
• D. Schistosoma

Explanation: The liver fluke (Fasciola hepatica) is an endoparasite of humans, cattle, and sheep. It completes its life cycle using two hosts: a snail as the intermediate host and a mammal (human, cattle, or sheep) as the definitive host. Tapeworms (Taenia) also infect humans and animals but usually require only one intermediate host, and Aurelia (jellyfish) and Schistosoma (blood fluke) have different life cycles.

Q91. A compound was found to contain nitrogen and oxygen in the ratio 28g:80g. The formula of the compound is:

• A. NO
• B. N2O3
• C. N2O4
• D. N2O5✓

Explanation: Mass of nitrogen is 14 g and mass of oxygen is 16 g. Dividing nitrogen’s mass in compound (28g) by 14g gives us 2. Dividing oxygen’s mass in compound (80g) by 16g gives us 5. So we can now say that the molar ratio of N to O is 2:5 that means the formula is N2O5

Q92. 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.

Q93. C12H22O11 + conc. H2SO4 → 12 C + ? + H2SO4

• A. 11 H2O✓
• B. 11 O2
• C. 11 CO2
• D. 11 H2

Explanation: Comparing reactant and product side we can see that there is a difference of 22 H and 11 O. That means the compound that we can make of it is 11 H2O. Hence the answer is A.

Q94. 22.4 dm3 of volume of each H2 and O2 are sparked to produce water vapours (considered as ideal gas) on completion of reaction. What is the decrease in the volume of the vessel?

• A. 44 dm3
• B. 22.4 dm3
• C. 33.6 dm3
• D. 11.2 dm3✓

Explanation: In the reaction, 2 moles of H2 react with 1 mole of O2 to form water vapor. Initially, there are 44.8 dm3 of gas (22.4 dm3 of each gas). According to the stoichiometry, 22.4 dm3 of H2 reacts with only 11.2 dm3 of O2, forming 22.4 dm3 of water vapor. The remaining 11.2 dm3 of O2 adds to the water vapor for a total final volume of 33.6 dm3. The initial volume was 44.8 dm3, so the decrease in the volume is 44.8 - 33.6 = 11.2 dm3. The other options misunderstand either the stoichiometry or the ideal gas volume concept.

Q95. Which of the following has six isotopes?

• A. Manganese
• B. Tin
• C. Calcium✓
• D. Carbon

Explanation: Calcium has six stable isotopes: 40, 42, 43, 44, 46, 48Manganese has four stable isotopes: 52, 53, 54, 55Tin has ten isotopes: 112, 114, 115, 116, 117, 118, 119, 120, 122, 124Carbon has three isotopes: 12, 13, 14.So option C is correct.

Q96. How many molecules are there in 2.1 moles of CO₂:

• A. 3.49 x 10⁻²⁴
• B. 2.53 x 10²⁴
• C. 1.26 x 10²⁴✓
• D. 3.79 x 10²⁴

Explanation: Since there are 2.1 moles of CO₂, we can easily find out the number of molecules present in it by multiplying 2.1 with the Avagadro's constant, which is 6.02 × 10²³. Hence, the answer would be approximately 1.2 x 10²⁴. The answer choice that is closest to the obtained value is 1.26 x 10²⁴. Please do not calculate the total number of atoms in this question; you have only been asked to calculate the total number of molecules.

Q97. Avogadro's constant is the number of:

• A. Electrons present in 2g of H
• B. Atoms in 24g of Mg✓
• C. Atoms in 1g of He
• D. Molecules in 35.5g of Chlorine

Explanation: Avogadro's Number (NA) is the number of atoms, molecules, ions, or anything in one mole of the respective substance. As 6.02 x 1023 atoms, molecules, ions, or electrons are present in one mole; therefore, this number is known as Avogadro's number.Only 24g of Mg equals one mole of Mg. Thus, only 24g of Mg has Avogadro's number of atoms.1g of He equals 1/2 mole of He. Thus it has half the number of atoms than Avogadro's number.35.5g of chlorine equals 1/2 mole of chlorine gas. Thus, it has half the number of molecules than Avogadro's number.2g of H equals two moles. Each mole of H atoms has 1 mole of electrons only, so two moles of H have twice the number of electrons than Avogadro's number.

Q98. One mole of substance at STP has:

• A. 2.24 dm³
• B. 24.4 dm³
• C. 2.44 dm³
• D. 22.4 dm³✓

Explanation: Under Standard Temperature and Pressure (STP), one mole of an ideal gas occupies 22.4 dm3.Under room conditions/ Normal Temperature and Pressure (NTP), one mole of an ideal gas occupies 24 dm3.

Q99. The mass number of an atom is:

• A. The number of electrons
• B. The number of neutrons
• C. The number of protons
• D. The number of neutrons and protons✓

Explanation: The mass number of an atom is defined as the sum of protons and neutrons that are present inside the nucleus of an atom. For example, the mass number of carbon is 12.01 amu as it has 6 protons and 6 neutrons in its nucleus.

Q100. Solid NaCl is a bad conductor of electricity because:

• A. Solid NaCl is covalent
• B. In the solid state, there are no ions
• C. In solid NaCl, there is no migration of ions✓
• D. In solid NaCl, there are not electron

Explanation: Conduction of electricity occurs when there is a free-moving charge (electrons or ions), so the answer is C.

Q101. Which of the following solids is an example of a substance with a macromolecular structure?

• A. Aluminium chloride
• B. Ice
• C. Magnesium oxide
• D. Silicon (IV) oxide✓
• E. Sodium chloride

Explanation: SiO2 has a macromolecular structure only among the compounds above. While other compounds possess a simple molecular structure, hence D is the correct option.

Q102. When does a gas deviate the most from its ideal behavior ?

• A. At low pressure and high temperature
• B. At high pressure and high temperature
• C. At low pressure and low temperature
• D. At high pressure and low temperature✓

Explanation: At high pressure and low temperature, a gas deviates the most from its ideal behaviour.Under these conditions, the gas molecules are close to each other and they exert significant intermolecular forces on each other. Also, the volume of gas molecules becomes a significant portion of total volume and cannot be neglected.Hence, the correct option is D.

Q103. When an element exists in more than one crystalline form, the phenomenon is termed as:

• A. Isomorphism
• B. Allotropy✓
• C. Isomerism
• D. Anisotropy
• E. Enthalpy

Explanation: Allotropy is the correct answer because it describes the ability of an element to exist in multiple forms or structures in the same physical state, such as carbon which can be found as diamond, graphite, and graphene.Isomorphism is incorrect as it refers to different substances with the same crystal structure. Isomerism is about different structural arrangements in organic compounds, not crystalline forms. Anisotropy deals with directional properties and not multiple forms of an element. Enthalpy involves thermodynamic measurements, not crystalline structures.

Q104. 950 torr corresponds to:

• A. 3.5 atm
• B. 1 atm
• C. 3 atm
• D. 1.25 atm✓
• E. 2.25 atm

Explanation: 1 atm = 760 torr To convert torr into atm Value of torr is divided by 760 950/760 = 12.5.

Q105. Which of the following statements is true for Amorphous solids?

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

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

Q106. A child's balloon has a volume 3.80 dm3, when the temperature is 35°C. If the balloon is put in a refrigerator and cooled to 5°C, the approximate volume of the balloon is (assume pressure inside the balloon is equal to atmospheric pressure):

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

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

Q107. If the matter in a given system at a given condition is divided into two equal parts, then the value of the extensive properties will become:

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

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

Q108. Comparative rates of diffusion of He and SO2 will be _.

• A. 8
• B. 2
• C. 4✓
• D. 16
• E. 64

Explanation: According to Graham's law of effusion, the rate of diffusion of a gas is inversely proportional to the square root of its molar mass. Therefore, the comparative rate of diffusion can be calculated using the formula: Rate of diffusion = √(M1/M2) Here, M1 is the molar mass of SO2 (64 g/mol), and M2 is the molar mass of He (4 g/mol). Plugging in these values gives: √(64/4) = √16 = 4. Therefore, the comparative rate of diffusion of helium to sulfur dioxide is 4. The incorrect options arise from not correctly applying the square root to the ratio of molar masses.

Q109. The unit of viscosity is:

• A. Joule
• B. N/m2
• C. Dynes/cm
• D. Poise✓
• E. Ergs

Explanation: The cgs unit of viscosity is poise (P) whereas the SI unit of viscosity is newton-second per square meter, which is usually expressed as pascal-second.

Q110. 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

Q111. Which of the following is the chemical formula of a compound indicating the relative number of atoms in the simplest ratio?

• A. Empirical formula✓
• B. Empirical formula mass
• C. Molecular formula
• D. Molecular mass

Explanation: The empirical formula expresses the simplest, most reduced ratio of the different types of atoms in a chemical compound. It provides information about the relative numbers of each type of atom present, and the ratios are always in the smallest whole numbers.

Q112. The equation shows the reaction between element X and dilute hydrochloric acid: X(s) + 2HCl(aq) -> XCl2(aq) + H2(g) What types of bonding is present in element X and in compound XCl2?

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

Explanation: Metallic bonding is a type of chemical bonding that arises from the electrostatic attractive force between conduction electrons (in the form of an electron cloud of delocalized electrons) and positively charged metal ions. The element X is metal as Metals react with halogens to form salts.The compound XCl2 is a salt and has ionic bonds. As two chlorine atoms are attached, this shows the central metal has two valence electrons in free states, so it is a metal of group II A[Be, Mg, Ca, Sr, Ba].

Q113. Linear combination of atomic orbitals (LCAO) results in the formation of:

• A. Sigma bond
• B. Pi bond
• C. Bonding molecular orbitals only
• D. Bonding and antibonding molecular orbitals✓
• E. All of these options

Explanation: According to Molecular Orbital Theory (MOT), two atomic orbitals overlap resulting in the formation of molecular orbitals. Number of atomic orbitals overlapping together is equal to the molecular orbital formed. The two atomic orbital thus formed by LCAO (linear combination of atomic orbital) in the same phase or in the different phase are known as Bonding Molecular Orbital (BMO) and Antibonding Molecular Orbitals (ABMO) respectively.

Q114. The raindrop acquires a spherical shape and ink spread over blotting paper due to:

• A. Surface tension✓
• B. Adhesive forces
• C. Viscosity
• D. Polarity
• E. Latent heat of vaporization

Explanation: A raindrop falling through the atmosphere forms a roughly spherical structure due to the surface tension of water. This surface tension is the “skin” of a body of water that makes the molecules stick together. The cause is the weak hydrogen bonds that occur between water molecules.

Q115. Sigma bond is formed by:

• A. Transferring the electrons
• B. Head-on overlapping of atomic orbitals✓
• C. Mutual but unequal sharing of electrons
• D. Parallel overlapping of atomic orbitals
• E. All of these options

Explanation: The sigma bond, the strongest type of covalent bond, is formed by the head-on overlapping of atomic orbitals. This overlap allows for maximum electron density between the two bonding nuclei, resulting in a stable bond. In contrast, ionic bonds are formed by the transfer of electrons (Option A), polar covalent bonds arise from mutual but unequal sharing of electrons (Option C), and pi bonds result from the parallel overlapping of atomic orbitals (Option D). Thus, Option B is the only correct description for sigma bond formation.

Q116. Choose the value of the Rydberg constant among the following values:

• A. 1.09678 x 107 m-1✓
• B. 1.602 x 10-19 C
• C. 1.7588 x 1011 C
• D. 1.007 x 107 m-1

Explanation: You’ll have to rote learn this. Memorise the power and units.

Q117. A 4s orbital has:

• A. One node
• B. Two nodes
• C. three nodes✓
• D. O nodes

Explanation: 4s orbital has 3 radial nodes plus 0 angular nodes

Q118. Electronic configuration of K is:

• A. [Ar] 4s2
• B. [Ar] 4s1✓
• C. [Kr] 4s1
• D. [He] 4s1

Explanation: The Potassium electron configuration will be 1s22s22p63s23p64s1. The electronic configuration of Argon is 1s22s22p63s23p6

Q119. An element has configuration 2, 8, 1. It belongs to, _.

• A. IA group and 3rd period✓
• B. IIIA group and 1st period
• C. IA group and 8th period
• D. VIIA group and 3rd period

Explanation: Elements’ position in the periodic table can be determined by its electronic configuration. Period can be determined by counting the number of shells its electrons occupy. Since the element shown occupies three shells so we can say that it is in Period III. Group can be determined number of electrons in the last shell. Since the element has 1 electron in its last shell so the group number of this element is 1.Hence the answer is A.

Q120. The maximum number of electrons in an atom with n=3 and l=2 is:

• A. 10✓
• B. 6
• C. 18
• D. 0

Explanation: In this case l = 2then m = −2,−1,0,+1,+2so there are 5 orbitals and each orbital contain 2 electronsSo for value n = 3 and l= 2 there are 10 electrons.The maximum number of electrons in a subshell with l=2 and n=3 is 10.

Q121. Which of the following has the maximum number of unpaired electrons?

• A. Mg2+
• B. V3+
• C. Ti3+
• D. Fe2+✓

Explanation: Iron ion (Fe2+) is the correct answer as it has the electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶, resulting in 4 unpaired electrons in the 3d subshell. This is the maximum number among the given options.Mg2+ has no unpaired electrons as its configuration is fully paired. V3+ has 2 unpaired electrons, and Ti3+ has 1 unpaired electron, both fewer than Fe2+.

Q122. The common features, among the species CN-, CO, and NO+ are:

• A. Bond order 3 and Isoelectronic✓
• B. Bond order three and weak field ligands
• C. Bond order two and π acceptors
• D. Isoelectronic and weak field ligands

Explanation: Each of these have same number of electrons;Number of electrons in CO = 6+8 = 14Number of electrons in CN- = 6+7+1 = 14Number of electrons in NO+ = 7+8-1 = 14 The species having same number of electrons are called iso-electronic. Iso-electronic species have same bond order.Bond order is number of chemical bonds present between a pair of atoms. There are 3 chemical bonds between C and O in CO, C and N in CN- and N and O in NO+ so all of these have same bond order of 3.Hence, all the given species are iso- electronic and have same bond order. So, option A is correct.CO and CN- are strong field ligands, while NO+ is weak field ligand. Weak field ligands are ones that produce small splittings between the d orbitals and form high spin complexes. Hence option B and D are incorrect.Weak field ligands are all π - donors.Strong field ligands are all π - acceptors.Hence option C is also incorrect.

Q123. In an adiabatic process:

• A. Pressure is maintained constant
• B. The gas is isothermally expanded
• C. There is perfect heat insulation✓
• D. System exchanges heat with the surroundings

Explanation: During an adiabatic process, the system is completely insulated from its surroundings. Thus, it takes place without heat entering or leaving the system, i.e.,q=0. During an isobaric process, the pressure of the system is kept constant (ΔP=0). During the isochoric process, the volume of the system is kept constant. (ΔV=0). During an isothermal process. the temperature of the system is kept constant (ΔT=0 but q≠0).

Q124. Standard heat enthalpy of a compound is equal to its:

• A. Heat of combustion
• B. Heat of formation✓
• C. Heat of solution
• D. Heat of dilution

Explanation: The enthalpy of reaction for any chemical reaction is equal to the difference between the sum of the enthalpies of the formation of the products and the sum of the enthalpies of the reactants. In an exothermic reaction, the heat content or enthalpy of the product H2 is less than that of the reactants H1. Since the system has lost heat, we can say the enthalpy change for the reaction ∆H is negative, In an endothermic reaction, the enthalpy of product H2 is greater than that of the reactants H1, and the enthalpy change, ∆H is positive. The standard enthalpy of a reaction ∆Ho is the enthalpy change that occurs when a certain number of moles of reactants as indicated by the balanced chemical equation, react together completely to give the products under standard conditions, i.e 25 °C (298K) and one atmosphere pressure. All the reactants and products must be in their standard physical states. Its units are kJ mol-1 .

Q125. For the reaction: N2 + 3H2 ⇌ 2NH3 .The production of NH3 will be favored at:

• A. High pressure and catalyst✓
• B. Low pressure only
• C. Low pressure and catalyst
• D. High pressure only
• E. Catalyst only

Explanation: The forward reaction forms fewer moles of gas (4 → 2), so high pressure shifts equilibrium toward NH₃. A catalyst increases the reaction rate but does not change equilibrium position. Therefore, maximum ammonia production is achieved using high pressure along with a catalyst.

Q126. According to the law of mass action,“The rate of chemical reaction” is proportional to the:

• A. The amount of product formed
• B. Product of the molar concentration of reactants✓
• C. The initial concentration of reactants
• D. Catalyst
• E. Pressure

Explanation: The speed at which the reactants are converted to products is called the rate of reaction. There are many factors that affect the speed of conversion of reactants into products:Nature of reaction: The state and number of reactants and complexity of reaction can affect the rate of reaction.Effect of concentration: From the law of mass action, the rate of reaction is directly proportional to the concentration of reactants, that is, the rate of reaction increases with the increase in the concentration of reactants.Pressure: The concentration of reactants can be increased by pressure. Hence, when pressure is increased the speed of reaction also increases.Catalyst: It can increase speed in both reverse and forward directions. This gives another path having low activation energy.Temperature: The reaction which takes place at a high temperature has more energy than a reaction at a low temperature. Now, we have to know what the law of mass action states which will give us a clearer answer to this question.The law of mass action states that, at a given temperature, the rate of a chemical reaction is directly proportional to the product of the molar concentrations of the reactants with their powers raised to their stoichiometric coefficient. The molar concentration of the reactant is also known as the: Q. Hence the correct option is B.

Q127. When 18 ×10-3 moles/dm3 of acetic acid react with 22×10-3 moles/dm3 of ethyl alcohol to form 40×10-3 moles/dm3 of ethyl acetate and 40×10-3 moles/dm3 of waterFind the value of equilibrium constant (Kc)

• A. 4.04✓
• B. 3.14
• C. 3.04
• D. 2.02
• E. 1.04

Explanation: Kc= Concentration of products / Concentration of Reactants. Reactants = acetic acid and ethyl alcohol Products = ethyl acetate and water Multiplication product of products (40 × 40 =1600) Divide by multiplication product of reactants (18× 22= 396) 1600/396= 4.04.

Q128. The enthalpy change accompanying the gain of an electron by a neutral gaseous atom to form a negative ion is called:

• A. Ionization potential
• B. Electronegativity
• C. Electron affinity✓
• D. Lattice energy
• E. Potential energy

Explanation: When an electron is added to a neutral gaseous atom to convert it into a negative ion, the enthalpy change accompanying the process is called Electron affinity enthalpy. Ionization potential, in chemistry, is the amount of energy required to remove an electron from an isolated atom or molecule. Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. Lattice energy is defined as the energy required to separate a mole of an ionic solid into gaseous ions. Potential energy is energy that is stored – or conserved - in an object or substance.

Q129. The heat of a reaction can be calculated by using:

• A. Joule's Law
• B. Ohm's Law
• C. Hess's Law✓
• D. Faraday's Law
• E. Boyle's Law

Explanation: Hess' law states that the change of enthalpy in a chemical reaction (i.e. the heat of reaction at constant pressure) is independent of the pathway between the initial and final states. In other words, if a chemical change takes place by several different routes, the overall enthalpy change is the same, regardless of the route by which the chemical change occurs (provided the initial and final conditions are the same). Hess’s law allows the enthalpy change (ΔH) for a reaction to be calculated even when it cannot be measured directly.

Q130. Bond energy:I. is the energy required to break a bond between two atoms in a diatomic molecule II. Is taken as the energy released in forming a bond form free atoms III. Is the measure of the strength of bond.

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

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

Q131. The study of measurement of heat absorbed or given out in a chemical reaction is referred to as:

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

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

Q132. Cl + e ----> Cl-ΔH = -348kJ/molThe value -348KJ/mol in this case will be:

• A. Ionization energy
• B. Electronegativity
• C. Electron affinity✓
• D. Entropy
• E. Free energy

Explanation: As it can be seen in the equation, electrons are gained by the element chlorine to form a negative ion (anion). The process in which electrons are gained is called electron affinity.

Q133. sp3 hybridization in CH4 gives it _ geometry.

• A. Linear
• B. Coplanar
• C. Tetrahedral✓
• D. Octahedral
• E. Trigonal pyramid

Explanation: The correct answer is Tetrahedral. In CH4, the carbon atom undergoes sp3 hybridization, forming four equivalent hybrid orbitals that orient in a way to minimize electron pair repulsion, resulting in a tetrahedral geometry. This arrangement allows for the formation of four equivalent C-H bonds with bond angles of approximately 109.5°.Other options are incorrect because:Linear: Associated with sp hybridization, not applicable to CH4.Coplanar: Linked to sp2 hybridization, not CH4.Octahedral: Requires six bonding sites, unlike CH4.Trigonal pyramid: Involves a lone pair, which CH4 does not have.

Q134. Dissolution of ammonium nitrate in water is an endothermic process. Which of the following graphs shows how the temperature alters as the ammonium nitrate is added to water and then the solution is left at room temperature?

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

Explanation: Since it is an endothermic process it takes heat from the surrounding making the temperature fall below room temperature. The temperature then gradually then goes back to room temperature.

Q135. Which of the following statements is NOT true for the first law of thermodynamics?

• A. Total energy of the system and surroundings is conserved
• B. Energy can neither be created nor destroyed
• C. The first law is synonymous with the law of conservation of energy
• D. Total energy of the system is increasing✓

Explanation: The first law of thermodynamics, also known as the law of conservation of energy, asserts that the total energy within an isolated system is constant. Energy may be transformed from one form to another or transferred between the system and its surroundings, but it cannot be created or destroyed. Therefore, the statement in Option D is incorrect as it contradicts this fundamental principle by suggesting that the total energy of the system is increasing.Options A, B, and C correctly reflect the principles of the first law of thermodynamics, emphasizing the conservation of energy and its equivalence to the law of conservation of energy.

Q136. A player throws a ball at an initial velocity of 36 m/second. The maximum distance the ball can reach (assume the ball is caught at the same height at which it was released) is:

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

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

Q137. A particle is projected at an angle of 45 degrees with a velocity of 9.8 m/s. The horizontal range will be:(g=9.8 m/s2)

• A. 6.9 m
• B. 9.8 m✓
• C. 15.6 m
• D. 4.9 m
• E. 3.1 m

Explanation: Attached below is the solution to the question above:

Q138. A shot leaves a gun at the rate of 160 m/s. Calculate the greatest distance to which it could be projected. (Take g = 10 m/s2).

• A. 2460 m
• B. 2560 m✓
• C. 2680 m
• D. 2760 m
• E. 2860 m

Explanation: For maximum distance(range) we assume that it is projected at 45 degrees. So, Rmax = u^2/g. (Following is the correct solution):

Q139. A constant force acting on a body of mass 5 kg changes its speed from 2 m/s to 7 m/s in 10 s the direction of motion of the body remains unchanged. Find the magnitude of the force.

• A. 0.5 N
• B. 1.5 N
• C. 2.5 N✓
• D. 3.5 N
• E. 4.5 N

Explanation: F= m(v-u)/t= 5(7-2)/10= 2.5N

Q140. What force should be applied on a 10 kg body so that it moves down in a vacuum with an acceleration of 3 m/s2 ? (Take g=9.8 m/s2)

• A. 42 N
• B. 46 N
• C. 68 N✓
• D. 53 N
• E. 58 N

Explanation: The question wants the object to only move down at 3 m/s2, we need to apply an upward force that would accelerate the object downwards at 9.8–3=6.8 m/s2. Using F=ma, where m = 10 kg and a = 6.8 m/s2, we find F to be 68 N upwards.

Q141. A rock is thrown straight upward from the edge of a 30 m cliff, rising 10 m then falling all the way down to the base of the cliff.Find the rock's displacement.

• A. 20 meters downward
• B. 30 meters downward✓
• C. 40 meters upward
• D. 50 meters upward
• E. 60 meters upward

Explanation: The displacement is the distance of the rock from the initial position, the initial position of the rock was at the cliff which was 30m. So the displacement of the rock is 30m downwards, although the distance traveled is 50m in total.

Q142. A stone dropped from a certain height can reach the ground in 5 seconds. It is stopped after 3 seconds of its fall and then allowed to fall again. Find the time taken by the stone to reach the ground for the remaining distance.

• A. 2 s
• B. 4 s✓
• C. 6 s
• D. 8 s
• E. 10 s

Explanation: The stone is initially dropped from a height and falls for 3 seconds before being stopped. During this time, it falls a certain distance which can be calculated using the equation of motion: s = ut + (1/2)gt², where u is the initial velocity (0 m/s), g is the acceleration due to gravity (9.8 m/s²), and t is 3 seconds.After being stopped, the stone falls the remaining distance, which is the difference between the total height and the distance fallen in the first 3 seconds. It takes 4 seconds to fall this remaining distance, calculated using the same equation of motion. Therefore, the correct answer is 4 seconds.The other options are incorrect because they either underestimate or overestimate the time required for the stone to fall the remaining distance.

Q143. A moon of mass ‘m’ orbits a planet of mass 100 m. Let the strength of the gravitational force exerted by the planet on the moon be denoted by F1, and let the strength of the gravitational force exerted by the moon on the planet be F2. Which of the following is true?

• A. F1 is ten times greater than F2
• B. F1 is ten times smaller than F2
• C. F2 is ten times greater than F1
• D. F2 is ten times smaller than F1
• E. F1 is equal to F2✓

Explanation: The gravitational force between two objects is proportional to the product of their masses and inversely proportional to the square of the distance between their centers. Since the mass of the planet is 100 times the mass of the moon, the strength of the gravitational force exerted by the planet on the moon will be much greater than the strength of the gravitational force exerted by the moon on the planet. However, the forces will still be equal in magnitude due to Newton's third law.

Q144. Which one of the following statements is true concerning the motion of an ideal projectile launched at an angle of 45° to the horizontal?

• A. The acceleration vector points opposite to the velocity vector on the way up and in the same direction as the velocity vector on the way down.
• B. The speed at the top of the trajectory is zero.
• C. The object's total speed remains constant during the entire flight.
• D. The horizontal speed decreases on the way up and also decreases on the way down.
• E. The vertical speed decreases on the way up and increases on the way down.✓

Explanation: The only external force acting on the object is the gravitational force vertically downwards. Thus the acceleration of the projectile is g downwards always. Thus there is no change in the speed of the object in the horizontal direction. The speed of an object in the vertical direction at the top of the trajectory is zero. However, the net speed at the point is equal to the constant horizontal component. Due to downward constant acceleration, the vertical speed decreases way up, becomes zero, and then increases way down. Thus option E is correct.

Q145. If a car collides with a housefly, what will be the magnitude of the force experienced by the housefly?

• A. Much greater than the force experienced by the car
• B. Much lesser than than the force experienced by the car
• C. Same as the force experienced by the car✓
• D. 10 times less than the force experienced by the car

Explanation: Yes, the same amount of force is imparted on each of them at the moment of the collision. However, one is affected much more than the other.Instead of thinking in terms of accelerating cars and flies, assume each has a constant velocity. At the moment of impact, each of them undergoes an acceleration (in the negative direction, so we usually call it deceleration) proportional to the force F of the impact. F is the same for both objects.Now, according to Newton's third law, at the moment of impact, the force that the car imparts on the fly is exactly equal to the force that the fly imparts on the car. Also, according to Newton's second law, the force is equal to mass times acceleration. As such, the train hits the fly with a massive amount of force, equal to the acceleration times the mass of the train.Results:The magnitude of force experienced by the housefly is the same as that experienced by the car neither less nor more because Newton's 3rd law is applicable here.

Q146. A 50 watt bulb is operated by 120 volts. What is the current through the bulb?

• A. 0.416 A✓
• B. 1.5 A
• C. 2.5 A
• D. 3.5 A
• E. 5.5 A

Explanation: P=IV(50)=(120)(I)50/120=II=0.416A

Q147. A battery of 6 volts is connected to two resistors of 3 ohm and 2 ohm joined together in series. What will be the current through the circuit?

• A. 6.2 A
• B. 5.2 A
• C. 4.2 A
• D. 2.2 A
• E. 1.2 A✓

Explanation: Resistance of resistors placed in series is calculated by adding the resistance,3+2=5 ohms.Formula connecting voltage,resistance and current is V=IR.V=IR(6)=(5)(I)6/5=I=1.2 Ohms.

Q148. There is a current of 25 A in a long straight wire. What is the flux density at a point 3 cm from the wire?

• A. 1.67 x 10-4 T✓
• B. 3.67 x 10-4 T
• C. 5.67 x 10-4 T
• D. 7.67 x 10-4 T
• E. 9.67 x 10-4 T

Explanation: Given, a=3cm=9×10−2m, I=25AB=μoI/2πa=4π×10−7×25/2π×3×10−2=1.67 x 10-4 T

Q149. A circuit in which there is a current of 5 amp is changed so that the current falls to zero in 0.1 s. If an average e.m.f of 200 volts is induced, what is the self inductance of the circuit?

• A. 1 Henry
• B. 2 Henry
• C. 3 Henry
• D. 4 Henry✓
• E. 6 Henry

Explanation: Initial current, I1=5.0AFinal current, I2=0AChange in current, dl=I1−I2=5ATime taken for the charge, t=0.1sAverage emf, e=200VFor self inductance(L) of the coil, we have the relation for average emf as:e=L x rate of change of currentL=e/rate of change of currentL=200/ 5/0.1L=4HHence the self inductance of the coil is 4H.

Q150. When the antinodes, in stationary waves, are passing through their equilibrium position, the energy is:

• A. Potential only
• B. Kinetic only✓
• C. A combination of both forms of energy
• D. There is no energy in stationary waves

Explanation: There is no energy transfer in stationary waves, but the energy of the antinodes keeps on changing from potential to kinetic energy. At the complete stretched position, the energy is wholly potential but as it passes through the equilibrium position, it is kinetic only.

Q151. If the body is rotating with uniform angular velocity, then its torque is:

• A. Zero✓
• B. 90
• C. 1
• D. -1

Explanation: Torque will be zero because the force on the object is zero, since it is not accelerating. And also if the body is at rest or rotating with uniform angular velocity the angular acceleration will be zero in this case the torque acting on a body will be zero.Torque is given by solution i.e. torque = r.F sin (theta)Here force = maAcceleration is given by change in velocity/timeIf the change in velocity is zero, acceleration is zero, force is zero, thus torque is also zero. Any other value is not remotely possible

Q152. A rescue helicopter drops a package of emergency ration to a stranded party on the ground. If the helicopter is traveling at 40 m/s at a height of 100 m above the ground, where does the package strike the ground relative to the point at which it was released? (g= 9.8 m/s2)

• A. 120 m
• B. 130 m
• C. 140 m
• D. 180.7 m✓
• E. 200.3 m

Explanation: (Following is the solution to the given problem.)According to the equation of motion: s= ut + ½ at2 Since the initial velocity would be zero S = ½ gt2 100= ½ (9.8) t2 t2= 100 x 2/9.8T2= 100/4.9T2= 20.4T= 4.5 According to the formula s= vt S=40 x 4.5 S= 180.7 m

Q153. A shot leaves a gun at the rate of 160m/s. Calculate the greatest distance to which it could be projected and the height to which it would rise? (g=10m/s2).

• A. 1560m, 540m
• B. 2560m, 640m✓
• C. 3560m. 740m
• D. 4560m, 840m
• E. 9595m, 348m

Explanation: R= u²sin2θ/gFor maximum range θ=45So 160²/10= 2650This alone is sufficient to enable us to narrow our answer to just B (do not waste time finding height while attempting the actual exam!)For height, H= u²sin²θ/2gat θ=45 H=u²/4g160²/4*10=640Which again confirms option B to be correct.

Q154. Law of conservation of momentum states that:I. there is no external force applied to a system, then the total momentum of that system remains constant II. if there is an external force applied to a system, then the total momentum of that system remains constant III. if there is no external force applied to a system, then the total momentum of that system keeps changing

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

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

Q155. Projectile must be launched at which angle with the horizontal to attain maximum range?

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

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

Q156. Example(s) of spin motion is/are:

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

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

Q157. 1 radian = _ degrees.

• A. 360
• B. 180
• C. 100
• D. 57.3✓
• E. 1.01745

Explanation: Radian is the SI unit of measuring angles. It is the measure of the central angle whose arc length is the same as the radius of the circle.In one circle,2π radians =3601 radian is equal to 180/π degrees, which is approximately 57.3°

Q158. The following question belongs to the topic of momentum:

• A. Current
• B. Length
• C. Angular momentum✓
• D. Torque
• E. Displacement

Explanation: The correct answer is Angular momentum. In three-dimensional space, the angular momentum of a point particle is defined as the cross product of its position vector (r) with respect to a given origin and its linear momentum vector (p). This forms a pseudovector, which is essential in describing rotational motion in physics. The other options are incorrect because they do not correctly describe the properties or definitions related to momentum or angular momentum. 'Current' relates to electric charge flow, 'Length' and 'Displacement' relate to measures of distance, and 'Torque' is a measure of rotational force, not a type of momentum.

Q159. To double the total energy for a mass-spring system oscillating in SHM, by what factor must the amplitude increase?

• A. 4
• B. 2
• C. √2 = 1.414✓
• D. ∜2 = 1.189

Explanation: The total energy of a mass-spring system in simple harmonic motion (SHM) is given by the formula: E = (1/2)kA^2, where k is the spring constant and A is the amplitude of oscillation. To double the total energy, you set up the equation: 2E = (1/2)k(A')^2 and solve for the new amplitude A'. Solving, we find A' = A * √2. Therefore, the amplitude must increase by a factor of √2 to double the total energy.Option A (4) suggests that quadrupling the amplitude is required, which would increase the energy by a factor of 16, not 2. Option B (2) suggests doubling the amplitude, which would increase the energy by a factor of 4. Option D (∜2) suggests an incorrect factor for doubling the energy. Therefore, the correct answer is Option C, √2.

Q160. Which graph in SHM shows the K.E of a body:

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

Explanation: The K.E of an oscillating body is maximum at the equilibirum position because speed is maximum at that point, and is 0 at the extreme positions because speed is 0 at those points. Graph B depcits the P.E, while Graph C depicts the TOTAL energy.

Q161. The time period of a second pendulum on the surface of the moon becomes:

• A. 2√6 seconds✓
• B. 1 second
• C. 2 seconds
• D. 6√2 seconds

Explanation: The time period of a simple pendulum is given by the formula: T = 2π√(L/g)On the Moon, gravity is 1/6 of Earth’s, so the pendulum’s time period becomes √6 times longer.If it’s 2 s on Earth, it’ll be 2√6 s on the Moon.

Q162. For a simple harmonic motion the acceleration of the body is _ to displacement and always directed towards _.

• A. Directly proportional ; maximum position
• B. Inversely proportional ; maximum position
• C. Directly proportional ; mean position✓
• D. Directly proportional ; minimum position

Explanation: For a simple harmonic motion, the acceleration of the body is directly proportional to the displacement and always directed towards the equilibrium position.In simple harmonic motion, the acceleration of the body is given by the equation:a = -ω²xwhere:a is the acceleration,x is the displacement from the equilibrium position, andω is the angular frequency of the motion.The negative sign indicates that the acceleration is directed towards the equilibrium position. This means that when the body is displaced from its equilibrium position, it experiences an acceleration that acts in the opposite direction, pulling it back towards the equilibrium. As the body moves towards the equilibrium position, the acceleration decreases until it reaches zero at the equilibrium point. Then, as the body moves away from the equilibrium in the opposite direction, the acceleration reverses its direction and continues to oscillate back and forth.The two conditions that have to be met for an oscillatory motion to be simple harmonic are:1- The acceleration is directly proportional to displacement.2- The displacement is always directed opposite to the direction of acceleration, i.e towards the mean position.

Q163. At which of the following places, motion of simple pendulum becomes slowest:

• A. Murree
• B. Karachi
• C. K-2✓
• D. Peshawar

Explanation: At higher altitudes, the value of g decreases slightly compared to its value at sea level. This is because the acceleration due to gravity is inversely proportional to the square of the distance from the center of the Earth. As you move farther from the Earth's surface (increasing in altitude), the value of g decreases.If we consider the effect of altitude on the time period of a pendulum, the decrease in g at higher altitudes will result in a longer time period. This is because the expression √l/g in the formula for T will have a larger denominator, making the square root term larger and, consequently, increasing the overall time period.In summary, at higher altitudes where the acceleration due to gravity is slightly lower, the time period of a simple pendulum tends to be longer compared to that at lower altitudes. However, the effect is generally small unless the altitude is significantly high or the precision of the measurement is extremely accurate.

Q164. Equation of SHM, with amplitude ‘a’ is given by:

• A. X = a(sin2 ω t + cos2 ω t)
• B. X = a(sin ω t cos2 ω t)
• C. X = a sin ω t✓
• D. X = a2 sin (sin ω t)

Explanation: X = a sin ω t is the standard equation of SHM, in which a corresponds to amplitude.

Q165. The six strings of a guitar are the same length under nearly the same tension, but they have different thicknesses. On which string do waves travel the fastest?

• A. The thickest string
• B. The thinnest string✓
• C. The wave speed is the same on all the strings
• D. None of the above

Explanation: The velocity of a transverse wave in a stretched string is given by: v = √(T/n). Where T is the Tension and n is the mass per unit lenthn = m/L = ρπr^2/L where r is the radius of the wirer = d/2 where d is the diameterSo, v = √ (4T/ρπd^2)v= 2/d √(T/ρπ)As it can be seen, v is inversely proportional to dThus, the velocity of wave is highest for thinnest string.

Q166. Two point charges of +5 C and -12 C attract each other with a force of 1.48 N. If charge of -5 C is added to each of these charges. Now the force will be:

• A. 1.48 N (attractive)
• B. 1.48 N (repulsive)
• C. 2.96 (repulsive)
• D. Zero✓

Explanation: The charges after adding -5C become:Q1 = +5-5 = 0CQ2 = -12-5 = -17CUsing formulaF= kq1q2/r21.48 = 9(109) (0)(17)/r2Since one charge is 0C, by muliplying it with other values the force will become zero.

Q167. A ship approaching a seaport at 10 km/h sends a sonic signal of frequency of 1000 Hz. What is the apparent frequency of the signal as received by a receiver on the seaport?

• A. 984 Hz
• B. 1000 Hz
• C. 1008 Hz✓
• D. 1210 Hz

Explanation: Frequency = 1000 HzSpeed of ship = 10 km/h = 2.78 m/sSonic signal speed = 340 m/sApparent frequency is found as:f’ = vsound / (vsound - vship) x ff’ = 340 / (340 - 2.78) x 1000f’ = 1008 Hz

Q168. In a ripple tank, 40 waves pass through a certain point in one second. If the wavelength of the waves is 5 cm, then find the speed of the wave:

• A. 2.7 m/s
• B. 3 m/s
• C. 200 m/s
• D. 2 m/s✓

Explanation: The formula for the speed of a wave is v=fλSince 40 waves pass through a certain point in one second, the frequency of the wave is 40 Hz. The wavelength of the wave is 5cm, which can also be written as 0.05m.v=0.05 x 40=2m/s

Q169. The product of frequency and time period is equal to:

• A. 2
• B. 3
• C. 0
• D. 1✓

Explanation: The product of frequency and time is equal to 1 according to the formula f=1/T where f represents the frequency having the units, seconds-1, and T represents the Time period having the units, seconds.

Q170. Trough of a wave acts as:

• A. Concave lens✓
• B. Convex lens
• C. Convex mirror
• D. Plane mirror

Explanation: We can see the waves on the screen. The crest acts as a convex lens while the trough acts as a concave lens.

Q171. In Doppler effect, if listener moves towards a stationary source then:

• A. Observed frequency is greater than original frequency✓
• B. Observed frequency is less than original frequency
• C. Observed frequency is equal to original frequency
• D. Observed frequency is independent of original frequency

Explanation: The Doppler effect describes how the frequency of waves changes based on the relative motion of the source and observer. When a listener moves towards a stationary source, the observed frequency increases because the waves are compressed, arriving more frequently than if the listener were stationary. Conversely, if the listener moves away, the waves are stretched, decreasing the observed frequency. If there is no relative motion, the observed frequency remains the same. Thus, option A is correct, while the other options describe scenarios not applicable to a listener moving towards a stationary source.

Q172. 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.

Q173. Suppose in a certain language MADRAS is coded as NBESBT. Then BOMBAY is coded in that language as:

• A. CPNCBZ✓
• B. CPNCBX
• C. CPOCBZ
• D. CQOCBZ

Explanation: As we can see the code exchanges each letter with the letter that follows it, so A becomes B, B becomes C, C becomes D, and so on. We will do this for each letter in Bombay and will arrive to: CPNCBZ.

Q174. The ‘A’ state government has chalked out a plan for the underdeveloped ‘B’ district where66% of the funds will be placed in the hands of a committee of local representatives.Courses of action:I. The ‘A’ state government should decide guidelines and norms for the functioning of thecommittee.II. Other state government may follow similar plan if directed by the Central government.

• A. If only I follows✓
• B. If only II follows
• C. If either I or II follows
• D. If neither I nor II follows

Explanation: Once it is decided to place funds in the hands of the committee of local representatives, it is necessary to decide guidelines and norms for the functioning of the committee. Hence I follows. II is not related to the statement.

Q175. The Emporium Mall has more stores than the Pakages Mall.The Amanah Mall has fewer stores than the Pakages Mall.The Emporium Mall has more stores than the Amanah Mall.If the first two statements are true, the third statement is

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

Explanation: ExplanationFrom the first two statements, you know that the Emporium mall has the most stores, so the Emporium Mall would have more stores than the packages Mall.

Q176. STATEMENTS:I. The dialogue between Jinnah and Gandhi failed.Il. Indian National Congress and Muslim League tried to join hands, so they will be united.

• A. Statement I is the cause and statement II is its effect.
• B. Statement II is the cause and statement I is its effect.
• C. Both statements I and II are independent causes
• D. Both statements I and II are the effects of independent cause.✓

Explanation: Gandhi and Jinnah were unable to reach a decision regarding Pakistan hence the dialogue failed. In order to show a united front to the British as they believe that would help them achieve independence INC and ML tried to join hands(work together). Thus both these statements are effects of independent causes.

Q177. Four people were witnessed as assaulted at an incident. Each of them have their own description of the scene. Which one will be probably right?

• A. He was average height, thin, and middle aged
• B. He was tall, thin, and middle aged✓
• C. He was tall, thin and young
• D. He was tall, of average weight, and middle aged

Explanation: Choice B gives accurate descriptions of all the features of the assailant/attacker. All other options have at least one vague description of the person such as, the average height in average weight in b, and young age in c.

Q178. Statements: 1. The temperature on Monday was lower than on Tuesday. 2. The temperature on Wednesday was lower than on Tuesday. 3. The temperature on Monday was higher than on Wednesday. If the first two statements are true, the third statement is:

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

Explanation: The statements establish that Tuesday had the highest temperature (Tuesday > Monday and Tuesday > Wednesday). However, they do not provide any information to compare the temperatures of Monday and Wednesday directly. Monday could have been warmer, colder, or the same temperature as Wednesday.

Q179. Passage: There is a family of six persons G, J, B, E, T and Z. Their professions are teacher, writer, actor, singer, dancer and lawyer but not respectively in the same order. G is a teacher. Z is a dancer. B is neither writer nor actor. E is neither singer nor lawyer. T is an actor. J is a lawyer. Who among them has a profession of lawyer?

• A. J✓
• B. B
• C. E
• D. T

Explanation: The passage explicitly states, "J is a lawyer." Therefore, J is the person with the profession of a lawyer.

Q180. Passage: There is a group of five students A, B, C, D and E from KIPS college. B and E are good in Dramatics and Computer Science. A and B are good in Computer Science and Physics. A, C and D are good in Physics and History. A and C are good in Physics and Mathematics. D and E are good in History and Dramatics. Who is good in Physics, History and Dramatics?

• A. A
• B. B
• C. C
• D. D✓

Explanation: We need to find the student who is listed in all three subject groups. D is listed as being good at "Physics and History" and also at "History and Dramatics." Combining these, D is good at Physics, History, and Dramatics.