Etea Mdcat 2005 — Solved Past Paper with Answers

Q1. From the moment he look over the public office, his actions have:

• A. Been loaded with significance and filled with worth
• B. Been significant with worthwhile✓
• C. To be loaded with significance and filled with worth
• D. Been actions of significance and worth

Explanation: We have to see grammatical mistakes and structure of sentence in wrong options.

Q2. Consider the·sentence "They made him king". Four choices are given below for this sentence to be rendered into 'passive voice'. Select the correct one.

• A. He has been made king by them
• B. He will be made king
• C. They will make king to him
• D. He was made king✓

Explanation: When a sentence is changed into passive voice, the meaning of a sentence doesn’t change, only the structures of words are changed. In active voice, action is done by the subject while in passive voice action is done by the object i.e. subject receives the action. In the given sentence the subject is ‘’they’’ object is ‘’King’’ and the verb is ‘’made’’. In passive voice, the object ‘’king’’ will become the subject as ‘’he’’, and the subject ‘’they’’ will become ‘’them’’. So the given sentence will become “He was made king by them” hence D is the closest answer.

Q3. Consider the sentence "They made him king". Four choices are given below for this sentence to be rendered into 'passive voice'. Select the correct one.

• A. He has been made king by them
• B. He will be made king
• C. They will make king to him
• D. He was made king✓

Explanation: When a sentence is changed into passive voice, the meaning of a sentence doesn’t change, only the structures of words are changed. In active voice, action is done by the subject while in passive voice action is done by the object i.e. subject receives the action. In the given sentence the subject is ‘’they’’ object is ‘’King’’ and the verb is ‘’made’’. In passive voice, the object ‘’king’’ will become the subject as ‘’he’’, and the subject ‘’they’’ will become ‘’them’’. So the given sentence will become “He was made king by them” hence D is the closest answer.

Q4. Consider the following sentence: He shouted, "Let me go". Which one of the following. stands for the "indirect speech" of the above sentence?

• A. He reqµested that let him go
• B. He shouted to let him go
• C. He shouted to them to let him go.✓
• D. He imported them to let me o.

Explanation: While converting sentences from direct to indirect speech, we must make sure to change all parts of the sentence, including changing the pronouns.

Q5. Note: Fill in the blank: He asked me to bring a chair and sit_him

• A. Next to✓
• B. Besides
• C. Towards
• D. Among

Explanation: Try reading the sentence out loud with each option and see which one sounds the most right.

Q6. A man of letters is:

• A. A postman
• B. A person who is fond of writing letters
• C. A man well versed in literature✓
• D. A man who writes letters for others

Explanation: A man of letters is a man engaged in literary pursuits, especially a professional writer, thus answer is C.

Q7. Choose the word closest in meaning to the word GENOCIDE:

• A. Self destruction
• B. Murder of a father
• C. Murder of a kin
• D. Killing, an entire race✓

Explanation: Genocide: the deliberate killing of a large number of people from a particular nation or ethnic group to destroy that nation or group. When a father is killed by his child, it's called patricide.

Q8. Which one of the following animals possesses an open circulatory system:

• A. Amoeba
• B. Earthworm
• C. Grasshopper✓
• D. Man

Explanation: Among the options provided, the animal that possesses an open circulatory system is the Grasshopper. An open circulatory system is a type of circulatory system where the circulating fluid, called hemolymph, is not confined to blood vessels but instead bathes the tissues directly. In this system, the hemolymph is pumped by a simple heart into the body cavity, where it comes into direct contact with the organs and tissues. The fluid then returns to the heart, and the cycle repeats. Now, let's go through the options: Amoeba: Amoebas are unicellular organisms and do not possess a circulatory system. Earthworm: Earthworms have a closed circulatory system. However, they have a modified version called a "closed circulatory system with open-ended vessels."

Q9. Which one of the following is the additional function of the embryonic membranes?

• A. Respiration and reproduction
• B. Reproduction and nourishment
• C. Strong of wase products
• D. Respiration and storage of waste products✓

Explanation: During the development of chick and other vertebrates, there are produced certain tissues or structures that temporarily or permanently do not enter into the formation of the embryo themselves but are external to and devoted in one way or another to the care and maintenance of the developing embryo. Collectively these parts are termed fetal membranes, extra-embryonic sacs, or extra-embryonic membranes. Extra-embryonic membranes developed are: i. Amnion or amniotic sac: which surrounds the embryo and provides a kind of private aquarium to protect it from mechanical shocks (such as pressure, abrasion, irritation) and desiccation. ii. A serosa or chorion: which forms the outermost membrane surrounding the rest of the embryonic system. iii. A yolk sac: which is filled with the yolk of the egg functions as the first respiratory organ and as a digestive organ for the embryo. It also acts as a hemopoietic organ like the liver and at later stages serves as a place of origin for blood cells. iv. An allantois: which is a precocious urinary bladder by origin, accumulates the embryonic nitrogenous wastes (non-toxic uric acid) and also acts as an embryonic respiratory surface. In short, They typically perform roles in nutrition, gas exchange, and waste removal

Q10. During inspiration the

• A. Chest wall is raised and diaghram is lowered✓
• B. Chest wall is raised and diaghram is also raised
• C. Chest wall is lowered and diaghram is raised
• D. Chest wall is lowered and diaghram is also lowered

Explanation: Ok we will go through inspiration and expiration on a conceptual basis During inspiration, air moves in the lungs, so atmospheric pressure inside the lungs must be lower than the outside so that air moves from higher pressure to lower pressure So for lowering pressure there must be an increase in the volume of the chest cavity, For that diaphragm contracts and moves downward(lowers), chest walls are raised These both events in addition to many other events cause an increase in the volume of the chest cavity, thus air moves in Opposite occur in expiration.

Q11. Pancreatic juice contains all except

• A. Amlyase
• B. Lipase
• C. Hydrochloric Acid✓
• D. Trypsin

Explanation: Pancreatic juice composition. Pancreatic juice is composed of water, mineral salts, enzymes, amylase, lipase, inactive enzyme precursors, trypsinogen and chymotrypsinogen, and procarboxypeptidase. The alkaline nature of pancreatic juice is attributed to the presence of bicarbonate ions, which are alkaline in the solution.

Q12. Consider the following names of some plants.

• A. Grapes
• B. Mango
• C. Oats✓
• D. Willow

Explanation: In inflorescence: Indeterminate inflorescence. A panicle is a branched raceme in which each branch has more than one flower, as in the astilbe (Astilbe). In angiosperm: Inflorescences. A panicle is a branched raceme in which the branches are themselves racemes (e.g.. yuccas)

Q13. Pumping denser blood causes the heart to be strained and waste product become cocentrated in the body. What is the cause of problems?

• A. Excess of water
• B. Deficiency of minerals.
• C. Deficiency of Minerals
• D. Dehydration✓

Explanation: Sometimes whole sentence is just for distracting the student, but you have to figure out which is important point. Like in this question denser blood.

Q14. The glucose is reabsorbed by the:

• A. Proximal convoluted tubule cof Nephron✓
• B. Distal convoluted tubule of Nephron
• C. Glomerulus
• D. Bowman\s capsule

Explanation: Glucose is a polar molecule that dissolves in water and blood plasma. It easily passes through the glomerular basement membrane. It is almost completely reabsorbed from the tubules by active transport molecules found in the proximal convoluted tubule (PCT) called sodium-coupled glucose cotransporters (SGLT).which is used for energy,

Q15. Plasmodium is found at different stages in man and mosquito. At which stage it can be seen in both the host?

• A. Ookinete
• B. Male gamete
• C. Oocyst
• D. sporozoite✓

Explanation: The explanation is given below:

Q16. Extra cellular digestion occurs in :

• A. Grasshoper and protozoa
• B. Grasshopper and frog✓
• C. Earthworm and protozoa
• D. Frog and protozoa

Explanation: Do you know what protozoans are? Yes, you do! They are single-cell organisms, just think if they are single-celled, why will they do extracellular digestion? They will digest inside the cell. So by reduction method A, C, and D options are wrong because they all contain protozoan, so no need to go deep(save time). Extracellular digestion refers to special molecules breaking down food for molecules outside the cell, contrasted by intracellular digestion which happens inside the cell. Intracellular digestion mainly occurs in unicellular organisms such as protozoans. In addition, extracellular digestion occurs in animals with a digestive system and fungi.

Q17. Where does the oesophagus open in the alimentary central of earthworm?

• A. Buccal chamber
• B. Intestine✓
• C. Rectum
• D. Intestinal caecum

Explanation: This needs a detailed analysis of the digestive system of earthworms.As this diagram shows esophagus opens into the intestine.

Q18. The gametophyte of Ulva is:

• A. Haploid✓
• B. Diploid
• C. Triploid
• D. Polyploidy

Explanation: Ulva cycles between two morphologically similar multicellular adult phases, a haploid gametophyte and a diploid sporophyte. Diploid sporophytes produce haploid zoospores that develop into gametophytes. Haploid gametophytes produce haploid gametes

Q19. Which of the following base is not present in RNA?

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

Explanation: DNA contains the following bases: adenine, guanine, cytosine, and thymine. RNA contains the following bases: adenine, guanine, cytosine, and uracil.

Q20. Where does the oesophagus open in the alimentary·central of earthworm?

• A. Buccal chamber✓
• B. Intestine
• C. Rectum
• D. Intestinal caecum

Explanation: The alimentary canal in earthworm has two openings, mouth at anterior end and anus at posterior end. Moith is also knwon as buccal chamber.

Q21. The gametophyte of Ulva is:

• A. Haploid✓
• B. Diploid
• C. Triploid
• D. Polyploidy

Explanation: Ulva cycles between two morphologically similar multicellular adult phases, a haploid gametophyte and a diploid sporophyte. Diploid sporophytes produce haploid zoospores that develop into gametophytes. Haploid gametophytes produce haploid gametes

Q22. Which of the following base is not present in RNA

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

Explanation: DNA contains the following bases: adenine, guanine, cytosine, and thymine. RNA contains the following bases: adenine, guanine, cytosine, and uracil.

Q23. Which of the following is not present in the fish?

• A. Middle ear✓
• B. Internal ear
• C. Gills
• D. Fins

Explanation: Option A: Middle ear and external ear are not found in fishes. All tetrapods i.e. amphibians, reptiles, birds, and mammals have a middle ear with a tympanic membrane. Option B: Fishes do have internal ears that pick up sound through their body. Many fishes rely on their ears to find habitat and mates, swim and avoid predators. Option C: Gills are present in fishes as they have a major role in respiration as well as osmoregulation, excretion of nitrogenous waste, pH regulation, and hormone production. Option D: Fins are also present in fishes and they help in swimming (locomotion), balance, and stability.

Q24. lactose, maltose and sucrose are the important

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

Explanation: Hence option B is the best answer.

Q25. Hyperfunctioning of thyroid glands will cause:

• A. Enlargement of bones
• B. Slow heart rate and nervousness
• C. Loss of body weight✓
• D. Sexual precocity

Explanation: Hyperthyroidism happens when the thyroid gland makes too much thyroid hormone. This condition also is called overactive thyroid. Hyperthyroidism speeds up the body's metabolism. Typical symptoms of hyperthyroidism are weight loss, fast heart rate, high irritability/nervousness, muscle weakness and tremors, infrequent menstrual periods, sleep problems, eye irritations, and heat sensitivity. Hence option c (loss of body weight) is the only correct symptom that matches with the symptoms stated above.

Q26. Qunine, a drug very effective against malaria, is derived from the bark of:

• A. Quina quina
• B. Lathyrus plant
• C. Calotropis plant
• D. Cinchona plant✓

Explanation: Fact. Quinine is an alkaloid derived from the bark of the South American cinchona tree. It has been used as an antimalarial for over 350 years.

Q27. The number of vertebrate in vertebrate column at man are:

• A. 37
• B. 35
• C. 34
• D. 33✓

Explanation: Vertebrae are the 33 individual bones that interlock with each other to form the spinal column. The vertebrae are numbered and divided into regions: cervical, thoracic, lumbar, sacrum, and coccyx shown below:

Q28. Which one of the following is necessary for evolution of seeds?

• A. Introduction of heterospory
• B. Rentantion of the megaspore within megasporangium
• C. Fertilization of the egg prior to discharge.
• D. All of the above✓

Explanation: All of the options given in the question are correct as there are various steps involved in the evolution of seed habit which are as follows: 1 Evolution of heterospory.2 Retention and germination of megaspore within the megasporangium.3 Development of protective layers around megasporangium.4 Reduction to a single functional megaspore per sporangium.5 Development of an embryo sac within the sporangium.6 Modification of distal end of megasporangium for pollen capture7 Pollen after being trapped in the distal cavity of the megasporangium produces a pollen tube that carries male gametes deep into the embryo sac to fertilize the egg, forming a zygote that forms an embryo. The megasporangium (ovule) after fertilization is transformed into a seed, the integuments becoming the seed coats. The seed offers a maximum degree of protection to a developing embryo under an unfavorable terrestrial environment. The development and evolution of seed habit was a great success and a giant leap that ultimately enabled plants to colonize land permanently.

Q29. The alternative form of given gene are called:

• A. Dominant
• B. Recessive
• C. Phenotype
• D. Alleles✓

Explanation: Fact. "Allele" is the word that we use to describe the alternative form or versions of a gene. Whereas Dominant refers to the relationship between two versions of a gene. Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked. And The observable characteristics in an individual resulting from the expression of genes are called phenotype.

Q30. All of the following are bacterial diseases except:

• A. Cholera
• B. Tuberculosis
• C. Typhoid
• D. Poliomyelitis✓

Explanation: Option A: cholera is caused by a bacterium called Vibrio cholera (hence incorrect). Option B: tuberculosis is also caused by a bacterium called Mycobacterium tuberculosis (hence incorrect). Option C: typhoid is also caused by a bacterium called Salmonella Typhi (hence incorrect). Option D: Poliomyelitis is caused by a virus called poliovirus that spreads from person to person and can infect a person's spinal cord, causing paralysis (can't move parts of the body).

Q31. In which of the following organs of woman does meiosis occur.

• A. Liver
• B. Kidney
• C. Ovaries✓
• D. Heart

Explanation: Meiosis is a process that occurs in sex cells, such as sperm and egg cells in the human body, to make more of them. Therefore, meiosis will occur in the reproductive organs i.e. the testes in males and the ovaries in females. In other organs, you would expect mitosis to occur.

Q32. In fungi the important adaptation for terrestrial mode of life is disappearance of:

• A. Rhizoids
• B. stolons
• C. sporongiophores
• D. Flagellated cells✓

Explanation: Explanation is given below:

Q33. DNA and histones together form a beed like structure called:

• A. Mesosome
• B. polysome
• C. Nucleosome✓
• D. Centrosome

Explanation: Mesosomes are a convoluted membranous structure formed in a prokaryotic cell by the invagination of the plasma membrane. They are involved in the synthesis of the cell membrane, replication of DNA, and protein synthesis. Therefore, A is incorrect. A polysome (AKA polyribosome) is a group of ribosomes bound to an mRNA molecule like “beads” on a “thread”. It consists of a complex of an mRNA molecule and two or more ribosomes that act to translate mRNA instructions into polypeptides. Therefore, B is incorrect. A nucleosome is the basic structural unit of DNA packaging in eukaryotes. The structure of a nucleosome consists of a segment of DNA wound around eight histone proteins and has a bead-like structure. Therefore, C is the correct answer. A centrosome is a cellular structure involved in the process of cell division. Before cell division, the centrosome duplicates, and then, as division begins, the two centrosomes move to opposite ends of the cell. Therefore, D is incorrect.

Q34. The mesodermal cell which give rise to urinary system in frog are called:

• A. Pincer cells
• B. Blastomers
• C. Nephrotome✓
• D. Parietal

Explanation: Pincer cells are deformed blood cells which are a characteristic feature of hereditary spherocytosis associated with Protein Band-3 deficiency. Therefore, A is incorrect. A blastomere is a type of cell produced by cell division (cleavage) of the zygote after fertilization; blastomeres are an essential part of blastula formation and blastocyst formation in mammals. Therefore, B is incorrect. The nephrotome is a section of the mesoderm that was thought to give rise to the pronephros and eventually to the rest of the kidney. Therefore, A is the correct answer. However, modern visualizing techniques such as scanning electron microscopy have shown this is not the case. Parietal cells (AKA oxyntic cells) are epithelial cells in the stomach that secrete hydrochloric acid (HCl) and intrinsic factors. These cells are located in the gastric glands found in the lining of the fundus and body regions of the stomach.

Q35. The growth and reproduction of eukaryotic cell is dependent upon its

• A. Cytoplasm
• B. Nucleus✓
• C. Vacuoles
• D. Nuclear pores

Explanation: The cytoplasm is the gel-like fluid inside the cell. It is the medium for chemical reactions. It provides a platform upon which other organelles can operate within the cell. Hence, A is incorrect. The nucleus is a spherical-shaped organelle that is present in every eukaryotic cell. The nucleus is the control center of eukaryotic cells. It is also responsible for the coordination of genes and gene expression. Therefore, B is the correct answer. Vacuoles are membrane-bound cell organelles that are primarily involved in storing nutrients and water for the cell. Hence, C is incorrect. Nuclear pores are protein-lined channels in the nuclear envelope that regulate the transportation of molecules between the nucleus and the cytoplasm. Hence, D is incorrect.

Q36. Cortisone is an important hormone of

• A. Adrenal cortex✓
• B. Adrenal medulla
• C. Cerebral cortex
• D. Cerebral medulla

Explanation: Cortisone is the man-made form of the natural hormone cortisol. Cortisol is a steroid hormone that is produced by the adrenal glands, which sit on top of each kidney. When released into the bloodstream, cortisol can act on many different parts of the body and can help the body respond to stress or danger and increase the body's metabolism of glucose. The hypothalamus produces corticotropin-releasing hormone (CRH) that stimulates the pituitary gland to secrete adrenocorticotropin hormone (ACTH). ACTH then stimulates the adrenal cortex to make and release cortisol hormones into the blood. Therefore, A is the correct answer.

Q37. Milk is pasteurized by heating at:

• A. 100°C
• B. 100°C for 30 min
• C. 71°C for 15 min and 62°C for 32 min✓
• D. 71°C for 32 min and 62°C for 15 sec

Explanation: Pasteurization is a food processing method where a mild heat treatment is applied to food to kill harmful bacteria (pathogens) and extend shelf life. In the pasteurization of milk, the milk is either heated to 71°C for 15 seconds or 62°C for about 30 minutes.

Q38. The number of vertebrae in coccyx are:

• A. 2
• B. 3
• C. 4✓
• D. 5

Explanation: Refer to the diagram below.The number of vertebrae in the coccyx is 4.

Q39. The genetic material of plant viruses mostly is:

• A. DNA
• B. RNA✓
• C. Both a and b
• D. Proteins

Explanation: The genetic material of plant viruses mostly consists of option B: RNA.Explanation:A) DNA: While some viruses, such as certain bacteriophages, have DNA as their genetic material, plant viruses predominantly have RNA. DNA-based plant viruses are relatively rare.B) RNA: RNA is the primary genetic material in most plant viruses. The RNA can be either single-stranded or double-stranded, and it can be positive-sense (directly translatable into proteins) or negative-sense (requires a complementary copy to be made before translation). Examples of plant viruses with RNA genomes include Tobacco mosaic virus (TMV) and Potato virus Y (PVY).C) Both A and B: While it is true that some plant viruses have DNA genomes, as mentioned earlier, they are relatively uncommon. Therefore, the majority of plant viruses have RNA as their genetic material.D) Proteins: Proteins are not the genetic material of plant viruses. However, proteins play a crucial role in the structure and function of the virus, including the formation of the viral capsid and the interaction with the host cell.In summary, the genetic material of plant viruses is predominantly RNA (option B), although there are some exceptions with DNA genomes.

Q40. The percentage of arthropods in the animal kingdom is:

• A. 45%
• B. 60%
• C. 75%
• D. 85%✓

Explanation: Fact

Q41. The epidermis of the xerophytes is covered with a waxy layer called:

• A. Cellulose
• B. Cuticle✓
• C. Chitin
• D. Lignin

Explanation: Cellulose is a tough, fibrous, and water-insoluble polysaccharide that plays an integral role in keeping the structure of plant cell walls stable. Therefore, A is incorrect. The cuticle is a barrier coating the outer surface of epidermal cells of organs of the aerial parts of the plants. It protects against water loss, various abiotic and biotic stress. Therefore, B is correct. Chitin is a fibrous substance consisting of polysaccharides and it is the major constituent in the exoskeleton of arthropods and the cell walls of fungi. Therefore, C is incorrect. Lignin is an important organic polymer that is abundant in the cell walls of some specific cells. It has many biological functions such as water transport, mechanical support, and resistance to various stresses. Therefore, D is incorrect.

Q42. The allele that exist in more than two different forms are called:

• A. Polygenic alleles
• B. Multigenic alleles
• C. Multiple alleles✓
• D. Heterogenic alleles

Explanation: In polygenic inheritance, each allele has a cumulative or additive effect on the phenotype thus generating continuous variation, e.g. skin pigmentation, height, etc. There is no such thing as a polygenic allele. Therefore, A is incorrect. Multigenic inheritance is another word for polygenic inheritance so the same applies here, there is no such thing as a multigenic allele. Therefore, B is incorrect. Multiple alleles of a gene occupy the same locus on the chromosome and are the alternative forms of the same gene so they influence the same trait. They usually exist in more than two forms, for example, the gene-determining blood groups. Therefore, the answer is C. Allelic heterogeneity is the phenomenon in which different mutations at the same locus lead to the same or very similar phenotypes. These allelic variations can arise as a result of natural selection processes, as a result of exogenous mutagens, genetic drift, or genetic migration. Therefore, D is incorrect.

Q43. In which part of the human body the bacteria are normally present in abundance:

• A. Salivary gland
• B. Stomach
• C. Intestine✓
• D. Liver

Explanation: While bacteria are found in the mouth, they are not found within glands like the salivary gland. Therefore, A is incorrect. Bacteria are not found in the stomach since one purpose of the HCl secreted is to kill any bacteria that find their way to the stomach. Therefore, B is incorrect. Bacteria are found in the intestines, especially in abundance in the large intestine. Bacteria in the large intestine have important roles, such as producing vitamins and controlling the growth of harmful bacteria. Therefore, C is correct. Bacteria are usually not found within organs like the liver.

Q44. In the human body all the given organs are vestigial except:

• A. Appendix
• B. Leg muscles✓
• C. Coccyx
• D. Nictitating membrane

Explanation: Vestigial organs are rudimentary anatomical structures that are retained in a species despite having lost their primary ancestral function. These structures often lack an apparent purpose, in contrast to the full functionality of these organs observed in closely related and ancestral species.

Q45. What is % of carbonhydrates in the mammalian cell per totall cell weight?

• A. 2
• B. 4✓
• C. 10
• D. 18

Explanation: 4 percent is correct option according to books4% is a reasonable and commonly accepted value that accounts for the total carbohydrate content in a mammalian cell by total wet weight. It fits within the typical range after accounting for water, proteins, lipids, and nucleic acids.

Q46. The rough endoplasmic reticulum is involved in the synthesis of:

• A. Proteins✓
• B. Carbohydrates
• C. Phospholipids
• D. Terpendoids

Explanation: rough endoplasmic reticulum (RER), a series of connected flattened sacs, part of a continuous membrane organelle within the cytoplasm of eukaryotic cells, that plays a central role in the synthesis of proteins.

Q47. Which one of the following has no digestive tube?

• A. Tape worm✓
• B. Liver fluke
• C. Planaria
• D. Round worm

Explanation: Correct answer is option A.

Q48. The transitory stage between cleavage and gastrulation is:

• A. Orgenogenesis
• B. Blastula✓
• C. Gastrula
• D. Development

Explanation: Zygote develops by a sequence of mitotic division, called cleavage, into a multicellular structure, first a solid ball of cells the module, and then a hollow ball of cells the blastula.

Q49. Which is least important in photosynthesis?

• A. Red light
• B. Blue light
• C. Sunlight
• D. Green light✓

Explanation: Greenlight range spectrum is considered as least effective for the process of photosynthesis: The wavelength of green light is thought to be the least efficient for photosynthesis. If the plants are exposed to green wavelengths during photosynthesis, the rate of photosynthesis will be the slowest. This is due to the presence of chlorophyll, a green pigment. Instead of being absorbed by the chlorophyll, the green light is transmitted and reflected. The best visible light wavelengths for photosynthesis are blue (425–450 nm) and red (600–700 nm).

Q50. In sickle cell hemoglobin only one glutamic acid of normal hemoglobin is replaced by?

• A. Valine acid✓
• B. Alamine acid
• C. Arginine acid
• D. Methionine acid

Explanation: Sickle cell anemia results from the single amino acid substitution of valine for glutamic acid in the beta-chain owing to a nucleotide defect that causes the production of abnormal beta-chains in hemoglobin S. (Hemoglobin S, a variant form of hemoglobin, is present in patients with sickle cell disease ).

Q51. Which one of the following is a marine alga?

• A. Nostoc
• B. Volvox
• C. Spirogyra
• D. Ulva✓

Explanation: Ulva: This is a small genus of marine and brackish water green algae. It is edible and is often called 'Sea Lettuce'.

Q52. The follicle stimulating hormone secreted by the pituitary glands stimulates the growth of:

• A. Uterus
• B. Ovaries
• C. Graffian follicles✓
• D. Urinary bladder

Explanation: In women, FSH helps manage the menstrual cycle and stimulates the ovaries to produce eggs.

Q53. Bacteria reproduce asexually by:

• A. Mitosis
• B. Meioses
• C. Conjugation
• D. Fission✓

Explanation: Bacteria reproduce primarily by binary fission, an asexual process whereby a single cell divides into two. Under ideal conditions some bacterial species may divide every 10–15 minutes—a doubling of the population at these time intervals.

Q54. Law of independent assortment cannot be applied on:

• A. Dominant genes
• B. Recessive genes
• C. Linked genes✓
• D. Autosomal genes

Explanation: When the two homozygous parents differing in two pairs of contrasting traits are crossed, the inheritance of one pair is independent of the other. In other words, when a dihybrid forms gametes, assortment (distribution) of alleles of different traits is independent of their original combinations in the parents. Many genes are located on one chromosome, i.e. they are linked. Therefore, they pass through gametes in the form of a linkage group. However, recombinations are due to the crossing over that takes place during meiosis. Therefore, the law of independent assortment is applicable only for the traits which are located on different chromosomes. Thus, law of independent assortment is not universally applicable.

Q55. Bauthinia variegate (kachnar) belongs to family:

• A. Leguminosae
• B. Soldnacoae
• C. Brassicaceae✓
• D. Graminea

Explanation: Bauhinia variegata is a species of flowering plant in the legume family, Fabaceae. The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family.

Q56. All of the following are angiosperms except:

• A. Cactus✓
• B. Amaryllis
• C. Spurge
• D. Firs

Explanation: Answer; A (It should be D instead. Although for A both angiosperm and gymnosperm is coming on different websites, since D is certainly gymnosperm answer should be it.)

Q57. What happens to oxygen in the electron trasfer chain in respiration?

• A. It is released asgas
• B. lt forms CO2
• C. It is reduced to water✓
• D. It is used as an electron carier

Explanation: In the electron transport chain (ETC) of cellular respiration, oxygen (O_2) serves as the final electron acceptor. Electrons, which have been passed down the chain from NADH and FADH2, are ultimately transferred to oxygen. Along with protons (H^+), oxygen is reduced to form water (H_2O). This process is crucial for generating the proton gradient that drives ATP synthesis.

Q58. When n-heptane is heated in the absence of air at high temperature in the presence of catalys it changes to 2,2,4 triethyle pentane. This process is called:

• A. Cracking
• B. Reforming✓
• C. Polymerisation
• D. Condensation

Explanation: As we see, just straight-chain alkane is converted into branched-chain alkane, nothing else and this conversion is called Reforming.

Q59. LaH2.75 is the formula

• A. Of normal binary hydride
• B. Of an interstilial hydride✓
• C. of covalent hydride
• D. That does not exist

Explanation: HYDRIDES Hydrogen compounds with metals and non-metals are known as hydrides. E.g, Ionic Hydrides: These are made by heating elements from groups I and II (excluding Be and Mg) in hydrogen. These are crystalline white colorless solids with high m.p. and b.p. that are quickly dissolved by water, CO2, or SO2.

Q60. The following reaction might be used for controlled nuclear fusion 3 Li7 + 1H2 ➔ 2(2He4) + X? What is the particle X?

• A. An alpha-particle
• B. An electron
• C. A neutron✓
• D. A proton

Explanation: Without going into deep discussions An easy way to solve such questions, is to balance charge(atomic number) and mass on both sides For that, first we must know the mass and charge of the given options An alpha particle has a mass of 4 and a charge of 2 An electron has mass taken as 0 and charge -1 A neutron has a mass of 1 and a charge of 0 A proton has mass 1 and charges +1 Balancing both sides of a given equation; Mass of Li + mass of H = 2(mass of He) + mass of X 7+2 = 2(4) + x x = 1 (Mass of particle) Now, charge of Li + charge of H = 2(charge of He) + charge of X 3+1 = 2(2) + x x = 0 (charge of the particle) So it coincides with the neutron

Q61. What happens to the molecule when its atoms are brought closer than the bond length between them?

• A. Molecule becomes unstable✓
• B. Molecule becomes more stable
• C. Molecule starts vibrating
• D. Stability of the molecule remains unchanged.

Explanation: Bond length is defined as the distance between two nuclei of atoms in a covalent bond. It can also be defined as the internuclear distance when there is a maximum possible orbital overlap. This distance is not actually constant, since the atoms are constantly vibrating. Therefore it is the average internuclear distance that is considered as bond length.

Q62. Rate of diffusion on NH3 is 1.6 times faster than CO2. The correct form of the rate law equilion for this statement will be:

• A. rNH3 /rCO2 =1/1.6
• B. rNH3 /rCO2 =1.6/1✓
• C. rCO2 /rNH3 = 1/1.6
• D. None of these

Explanation: In this question, we don't have to apply Grahm's law cuz it is far simple What they said, rNH3=1.6(rCO2) ,the questions word in equation Now we can also write it as rNH3/rCO2 = 1.6/1 But wait isn't option C is same just reprocalliting on both sides? Two options right, what to do now? Select in Alphabetic order, so we will select option B Dont say, you don't know, rNH3 means rate of diffusion of NH3 rCO2 means the rate of diffusion of CO2

Q63. Consider the reaction 3H2 (g} + N2 (g) ➔ 2NH3 (g). All of the following will lead to this reaction to the production. of more NH3 except:

• A. A decrease in the volume of the container .
• B. An increase pressure by addition of hydrogen
• C. Removal of NH3
• D. An increase in pressure by addition.of nitrogen✓

Explanation: To do such questions, Your concepts about the Le Chatelier principle must be clear and you must know how to apply that.

Q64. If a single balloon is filled with equal volumes of hydrogen, helium, nitrogen, and neon, which gas will be deleted first?

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

Explanation: This concept is related to the process of effusion.Effusion is the process in which a gas escapes from a container through a hole of a diameter considerably smaller than the mean free path of the molecules. Now obviously the gas having the smallest size will effuse at a greater rate, even through small pores.Of the given options, Hydrogen has the smallest size.You might be thinking that helium is smaller than hydrogen because size decreases across the group.But helium is a noble gas and noble gasses have greater size.

Q65. Which one of the following is the strongest acid?

• A. CH2Cl-H2-COOH
• B. CHCl2COOH✓
• C. CH3 COOH
• D. CH3- CH2-COOH

Explanation: Many concepts are required to be cleared while solving these types of MCQsFirst, we should know, those acids are the strongest which can lose hydrogen easily( specifically talking about organic acids)Oxygen in the functional group has lone pairs and has a partially negative charge, so it binds with hydrogen strongly having a partially positive charge, but when an electronegative atom ( such as halogen) will be present, this partially negative charge will be withdrawn by halogen,making oxygen less negative, so it will now not bind with hydrogen as strongly as it was, so hydrogen losing capacity will be increased making acid strongerSecondly, if that halogen is bonded to a carbon atom nearer to alpha carbon it will have more withdrawing effect on oxygen, making acid stronger, As in option A it is bound with C-2, while in option B it is bound to C-1 (nearer to alpha carbon), making acid in option B stronger, moreover in option B two Cl atoms are bonded having a more withdrawing effect, making it stronger acid.A: It is stronger than the one in option B.

Q66. The enormous diversity of protein molecules is mostly due to the diversity of:

• A. Amino groups on the amino acids
• B. R- groups on the amino acids·✓
• C. Peptide bonds
• D. Amino acids sequences within protein molecules

Explanation: Diversity refers to different types of proteins.

Q67. Identify the compound formed when ethylene combines with water in the presence of 10% sulphuric acid and HgSO4 as a catalyst.

• A. Carbinol
• B. Methanol
• C. Ethanol✓
• D. Glycol

Explanation: Ethylene we know is an alkene They mentioned ethylene is going to react with water, it means it is hydration of an alkene And we know hydration of alkene produces alcohol in the presence of a catalyst that is 10℅ sulphuric acid and HgSO4

Q68. Which one of the following is NOT correct?

• A. Chlorine gas is used to prepare germicide and pesticide
• B. Hydrogen gas is used for the preparation of vegetable ghee
• C. Alums are used for tanning of hude✓
• D. Aluminium is used as mordant

Explanation: Al is not used for tanning of hude.

Q69. Catenation is a process in which carbon shows the properties of making:

• A. Multiple bonds
• B. Hybridization
• C. Long chain or rings of carbon atoms✓
• D. Showing isomerism

Explanation: Catenation is the bonding of atoms of the same element into a series, called a chain. A chain or a ring shape may be open if its ends are not bonded to each other (an open-chain compound), or closed if they are bonded in a ring (a cyclic compound).

Q70. Silver nitrate solution turns blue when a piece of copper is added to it. This is because of

• A. Oxidation of Ag
• B. Reduction of Cu
• C. Oxidation of Cu✓
• D. Ionization of Ag

Explanation: When copper wire is placed in silver nitrate solution then the solution becomes blue colored. We will use electrochemical series to solve the question. Copper is more reactive than silver. Hence when the copper wire is dipped in silver nitrate solution it displaces silver from silver nitrate (AgNO3) solution forming copper nitrate which is bluish-green.This is a displacement reaction. A shining gray-white deposit of silver is formed on the copper strip and therefore the solution becomes bluish-green because of the formation of copper nitrate. We observe that the solution becomes blue

Q71. In which of the following solvents are alkenes the more soluble?

• A. Water
• B. Ethyle alcohol
• C. Ammonia
• D. Carbon tetrachloride✓

Explanation: We also know alkenes are non-polar, with negligible electronegativity difference between carbon and hydrogen and no difference between carbon and carbon. So it will be more soluble in non-polar solvents.

Q72. The compound B formed in the sequence of reaction is

• A. Propylene
• B. Propane
• C. Propene✓
• D. Propanol

Explanation: To solve such questions, the catalyst tells the whole answer, In the first step alcohol is reacted with PCl3 to form a product A Alcohol in reaction with PCl3 will form alkyl halide along with H3PO3 which is a byproduct The same no of carbons are in alkyl halide as are in alcohol So propyl chloride will be produced We consider only the main product while further solving Now A is reacted with alcoholic KOH We must know alcoholic KOH causes elimination making C=C As CH3-CH2-CH2-Cl +alcohlic KOH ——› CH3-CH=CH2 +HCl We consider the main product So B is propene

Q73. Which of the following pairs of molecules have similar geometry?

• A. CO2 and SO2
• B. BF3 nad NH3
• C. MgCI2 and AICI3
• D. CH4 and SiH4✓

Explanation: The shape of molecules can be predicted by VSEPR theory. According to this theory the shapes or geometry of a molecule or ion depends on the number of shared pairs as well as lone pairs of electrons around the central atom of the molecule or ion which is mainly determined by the repulsive interactions all electrons pairs in the valence shell of central atom.

Q74. A mixture of 50gH2 and 50gHe has a total pressure of 1.5atm. What is the partial pressure of H2 gas?

• A. 1.0 atm✓
• B. 2.0 atm
• C. 1.5 atm
• D. 3.0 atm

Explanation: Partial Pressure = Mole Fraction x Total Pressure Find moles of hydrogen and helium; moles = mass/Mr; moles = 50/2 = 25 moles of hydrogen moles= 50/4 = 12.5 moles of helium Total moles = 12.5 + 25 = 37.5 moles Hence; Partial pressure of hydrogen = mole fraction x total pressure = 25/37.5 x 1.5 =1.0 atm (hence option A is the correct answer)

Q75. Silver nitrate solution turns blue when a piece of copper is added to it. This is because of:

• A. Oxidation of Ag
• B. Reduction of Cu
• C. Oxidation of Cu✓
• D. Reduction of Ag

Explanation: When copper is added to silver nitrate solution, the following reaction takes place:

Q76. In which of the following solvents are alkenes the most solvent?

• A. Water
• B. Ethyle alcohol
• C. Ammonia
• D. Carbon tetrachloride✓

Explanation: Alkenes are only soluble in nonpolar solvents.

Q77. A solution of 2.0g NaOH dissolved in 1000 g of water has the following concentration:

• A. 0.50m
• B. 0.05M✓
• C. 0.05 N
• D. 0.05m

Explanation: 0.05M is the correct answer as “Molar” is the unit of concentration. Since 1 liter of water weighs 1kg i.e 1000 grams hence volume of solution= 1 liter Moles of NaOH= mass / Mr = 2 / 40= 0.05 moles So concentration of NaOH= moles / volume = 0.05 / 1 = 0.05 M

Q78. When aldehyde is warmed with Fehling reagent;

• A. A red precipitate of CuO is formed✓
• B. A black precipitate of CuO is formed
• C. Silver mirror is formed
• D. No reaction occurs

Explanation: Aldehyde reacts with Fehling reagent through the following reaction: Diagram This is an oxidation reaction in which copper oxidizes alkyl halide and itself reduces from (Cu2+) +2 to (Cu2O) +1 giving a red-brown precipitate hence it is the correct answer.

Q79. The net heat change in a chemical reaction is smae weather it takes place in one ste or several steps. This law is known as:

• A. First law of thermodynamics
• B. Henery's law
• C. Hess's law✓
• D. Joule's law

Explanation: Option A: The first law of thermodynamics states that energy can neither be created nor destroyed, only altered in form. Hence incorrect. Option B: Henry's law is a gas law that states that the amount of dissolved gas in a liquid is directly proportional to its partial pressure above the liquid. The proportionality factor is called Henry's law constant. Hence incorrect. Option C: Hess's law states that the overall change in enthalpy for a chemical reaction is equal to the sum of the enthalpy changes for each step. And this is independent of the path taken. Hence it is the correct option. Option D: Joule's law states that the amount of generated heat in a conductor carrying current is proportional to the square of the current flow through the circuit when the electrical resistance and current supply are constant. Hence incorrect.

Q80. In a reaction of ethane and hydrochloric acid, the hydrogen ion acts as:

• A. Nucleophiles
• B. Electrophiles✓
• C. Carbon ions
• D. Carbonium ions

Explanation: Alkenes undergo electrophilic substitution reaction. Hence in the reaction between ethene and HCl, hydrogen acts as an electrophile and is added first followed by the addition of chlorine. The mechanism of this reaction is given below for a better understanding:

Q81. Which compound reacts with chlorine to give two products in which chlorine has deifferent oxidation number?

• A. Ethane
• B. Potassium iodate (V)
• C. Sodium hydroxide✓
• D. Potassium hydroxide

Explanation: Chlorine reacts with sodium hydroxide to give NaCl and NaClO where oxidation states of Cl are different. This reaction along with the oxidation states is given below:

Q82. When magnesium reacts with steam what would be the end product?

• A. Mg (OH)
• B. MgO✓
• C. MgO 10H2O
• D. MgO2

Explanation: Metals react with water under different conditions and produce metal oxide or hydroxide and liberate hydrogen gas. When magnesium reacts with liquid water Mg(OH)2 and H2 gas is formed by the following reaction: Mg + 2H2O → Mg(OH)2 + H2 But when magnesium reacts with steam MgO and H2 gas is formed by the following reaction: Mg(s) + 2H2O(g) → Mg(OH)2 (aq) + H2(g) Hence B is the correct answer

Q83. What is the oxidation state of sulphur in sulphuric acid (H2SO4)?

• A. -6
• B. +6✓
• C. -4
• D. +4

Explanation: In sulfuric acid (H2SO4), Hydrogen exists in its normal oxidation state of +1 and Oxygen exists in its normal oxidation state of -2. Since the overall compound H2SO4 is neutral, we know the sum of the oxidation states of all elements in the compound must be equal to 0. Let the oxidation state of Sulfur be x. 2(+1) + 1(x) + 4(-2) = 0 2 + x - 8 = 0 x - 6 = 0 x = +6 Therefore, B is the correct answer.

Q84. In the given Exothermic reaction PCl3 + Cl2 (g) ➔PCl5(g) an increase in yield will be favoured by:

• A. Decrease of temperature✓
• B. Increase of temperature
• C. Keeping temperature constant
• D. None of these

Explanation: Since the forward reaction is exothermic, decreasing the temperature will cause the reaction to shift in the forward direction by Le Chatlier’s principle.

Q85. Crystals in general, may have grater refractive index or electrical conductivity in one direction than another. it is called:

• A. Polarity
• B. Optical activity
• C. Anisotropy✓
• D. Cleavage plane

Explanation: .A is incorrect since polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole moment, with a negatively charged end and a positively charged end. Polarity has no link to the refractive index or electrical conductivity in one direction. B is incorrect since optical activity is the ability of a substance to rotate the plane of polarization of a beam of light that is passed through it. Optical activity has no link to the refractive index or electrical conductivity in one direction. C is correct since the physical properties that depend upon the direction are called anisotropic properties and the phenomenon is referred to as anisotropy. The physical properties of crystalline solids like refractive index, coefficient of thermal expansion, and electrical and thermal conductivities are sometimes anisotropic for some crystals. The variation in these properties with direction is because the orderly arrangement of the particles in crystalline solids is different in different directions. For example, the electrical conductivity of graphite is greater in one direction than in another. D is incorrect since the plane surfaces formed by the breaking of a crystal are known as crystal cleavage planes. The angle between the adjacent cleavages of a crystal of a substance are the same but are different in the crystals of different substances. In other words, these angles are characteristics of crystalline solids. Cleavage itself is an anisotropic property but not what the question is asking for.

Q86. Which metal imparts green color to bunsen flame?

• A. Na
• B. Ca
• C. Sr
• D. Ba✓

Explanation: A flame test is an analytical procedure used by chemists to detect the presence of particular metal ions, based on the color of the flame produced. When heated, the electrons in the metal ion gain energy and can jump into higher energy levels. Because this is energetically unstable, the electrons tend to fall back down to where they were before, releasing energy as they do so. This energy is released as light energy, and as these transitions vary from one metal ion to another, it leads to the characteristic colors given by each metal. A) Sodium has a golden yellow color flame. B) Calcium has a brick-red color flame. C) Strontium has a crimson-red color flame. D) Barium has a pale or grassy green color flame. Therefore, D is the correct answer.

Q87. What is the oxidation number of hydrogen in metal hydrides?

• A. 0
• B. +1
• C. 2
• D. -1✓

Explanation: .Metal hydrides are defined as compounds that are formed when a metal element is bonded to hydrogen. In metal hydride, the metal is present in the form of cation and hydrogen is present in the form of anion. The hydrogen anion acts as a nucleophile in metal hydride compounds and the oxidation state of hydrogen is -1. Therefore D is the correct answer.

Q88. Consider the reaction: NO2(g)+CO(g) ➔ NO(g)+CO2(g). it shows that the reaction is:

• A. Bimolecular✓
• B. Unimolecular
• C. Trimolecular
• D. Tetramolecular

Explanation: The molecularity of a reaction is defined as the number of reacting molecules that collide simultaneously to bring about a chemical reaction. In other words, the molecularity of a reaction is defined as the number of reactant molecules taking part in the reaction.

Q89. Copper displace which of the following metals from its salt solution:

• A. ZnSO4
• B. FeSO4
• C. AgNO3✓
• D. All of the above

Explanation: For a metal to be displaced in a salt solution, the metal being added must be more reactive than the metal cation in the salt.

Q90. The number of oxygen in 0.5 mole of AI2 (CO3)3 is:

• A. 4.5 x 1023
• B. 3.6 x 1024
• C. 2.7 x 1024✓
• D. 9.0 x 1023

Explanation: In one molecule of aluminum carbonate, there are 3 molecules of carbonate ions, which have 3 oxygen atoms each so there are 9 atoms of oxygen in 1 molecule of aluminum carbonate. Therefore in 0.5 moles of aluminum carbonate, there are 0.5NA particles of aluminum carbonate which means there are 9 * 0.5NA = 4.5 NA particles of oxygen. 1 NA = 6.02 x 1023 so 4.5 NA = 4.5 x 6.02 x 1023 = 27 x 1023 = 2.7 x 1024 atoms of oxygen. Hence, C is the correct answer.

Q91. Which one of the following chemical reactions is represented by the equation: CI2+kBr ➔ KCl + Br2?

• A. Decomposition
• B. Redox✓
• C. Hydration
• D. Precipitation

Explanation: In a redox reaction, one substance is oxidized during the reaction (oxidation number increases) and another is reduced (oxidation number decreases. In this case, the oxidation state of Br in KBr is -1 and in Br2 is 0 so Br is oxidized. The oxidation state of Cl is 0 in Cl2 and -1 in KCl, so Cl is reduced. Therefore, this is a redox reaction and B is correct.

Q92. Which gas deviates most ideal behavior at room temperature and pressure?

• A. Hydrogen
• B. Nitrogen
• C. Methane
• D. Sulphur dioxide✓

Explanation: For gas to deviate from ideal behavior, there should be significant intermolecular forces present in the gas. The order of intermolecular forces in gases is: London dispersion forces < Permanent dipole-dipole interactions < Hydrogen bonding.

Q93. When the value of principal quantum No: is n =2 the value of magnetic quantum number (m) is?

• A. +1, 0, -1
• B. 0, +1, +2
• C. -1, 0, +1✓
• D. 0, -1, +1

Explanation: The Magnetic Quantum Number (m) specifies the orientation in space of an orbital of a given energy (n) and shape (l). This number divides the subshell into individual orbitals which hold the electrons; there are 2l+1 orbitals in each subshell, ranging from -l to 0 to +l. The azimuthal (or orbital angular momentum) quantum number describes the shape of a given orbital and is denoted by l. The values of l range from 0 to n – 1. The principal quantum number, n, describes the energy of an electron and the most probable distance of the electron from the nucleus (i.e. the shell number. In this case, n = 2, so l can be either 0 or 1, and m can then be either 0 or -1, 0, +1. This order is only found in C, so it is the correct answer. A and D also have the correct values but they are in the wrong order. The values in B are not possible.

Q94. Which ion is present in the highest concentration in a 2 mole/cm3 solution of sodium sulfate?

• A. The hydrogen ion, H+
• B. The hydroxide ion, OH-
• C. The sodium ion, Na+ (aq)✓
• D. The sulphate ion, SO4-2 (aq).

Explanation: .Na+ ions will be present in the highest concentration since there are 2 moles of Na+ in each mole of Na2SO4, so the concentration of Na+ is 4 moles/cm3. Therefore, C is the correct answer.

Q95. The study of heat changes accompanying a chemical reaction is known as:

• A. Thermo-chemistry✓
• B. Thermodynamics
• C. Electro chemistry
• D. Chemical kinetics

Explanation: Thermochemistry is the study of the heat energy which is associated with chemical reactions and/or phase changes such as melting and boiling. Therefore, A is the correct answer.

Q96. Which one of the following is not a physical property?

• A. Corrosion✓
• B. Sotubility
• C. Melting point
• D. Boiling point

Explanation: A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. A chemical property describes the ability of a substance to undergo a specific chemical change.

Q97. On complete oxidation, one mole of an organic compound gave four moles of water. The compound Could be

• A. Methanol
• B. Propane✓
• C. Ethylene
• D. Benzene

Explanation: Upon complete oxidation, propane (C3H8​) gives 4 moles of water:C3H8+5O2→3CO2+4H2O

Q98. Water is not used as a therometric liquid mainly because of:

• A. Colorless
• B. Is a bad conductor
• C. Does not expand linearly✓
• D. Has a low boiling point of 100oC

Explanation: The correct answer is that water does not expand linearly. Water's anomalous expansion, particularly its contraction from 0°C to 4°C and subsequent expansion, leads to non-linear behavior that renders it unsuitable as a thermometric liquid. An accurate thermometer requires a liquid that expands uniformly with temperature changes. While its boiling and freezing points limit its range, these are not the fundamental reasons for its unsuitability, as demonstrated by other liquids used in thermometers for specific temperature ranges.

Q99. Calculate the number of moles of NaCl in 75.0g of table salt.

• A. 0.643
• B. 0.779
• C. 28.0
• D. 1.28✓

Explanation: 1 mole: 58.5 g of NaCl x mole: 75 g of NaCl x=1.28

Q100. Oxygen molecule has two unpaired electrons. It is therefore,

• A. Ferromagnetic
• B. Diagmagnetic
• C. Electromagnetic
• D. Paramagnetic✓

Explanation: A ferromagnetic substance, like iron, retains magnetic properties after removing the field. On the contrary, oxygen does not have this magnetic property once the field is removed; hence, it is a paramagnetic substance. B: Diamagnetic substance: The compounds or molecules which have only the paired electron in their orbital are called diamagnetic substances. C: Electromagnetic is used to describe the electrical and magnetic forces or effects produced by an electric current. D: Paramagnetic substance: The compounds or molecules which have at least an unpaired electron in their orbitals are called paramagnetic substances. In an oxygen molecule, there are two unpaired electrons in its molecular orbital. So it has paramagnetic properties. As free electrons move on their axis to produce a magnetic field. Hence, oxygen is a paramagnetic substance.

Q101. The sample of a compound contains 0:100g of hydrogen and 4.20 of nitrogen. The simplest formula for the compound is:

• A. HN2
• B. NH3
• C. HN3✓
• D. NH2

Explanation: H N Moles: 0.1/1 4.20/14Divide by the smallest number calculated : 0.1/0.1 0.3/0.1Answer: 1 3HN3

Q102. Wltat type of hybrid orbits are used by the carbon atoms in C2H4?

• A. sp
• B. sp2✓
• C. d2s
• D. p2

Explanation: Trick: See the number of electron clouds around the C atom (1 electron cloud= single bond/double bond/ triple bond). Since C has 3 electron clouds it'll have 3 hybridized orbitals i.e. it is sp² hybridized (1 s and 2 p hybridized orbitals). For a detailed explanation:

Q103. Esters are represented by the general formula:

• A. ROP
• B. BOOR
• C. RCOOR✓
• D. RCOOH

Explanation: RCOOR is the general formula of esters.

Q104. Her brother along with her parents_ that she remain in school.

• A. Insist
• B. Insists
• C. Are insisting✓
• D. Were insisting

Explanation: .This phrase goes perfectly with the sentence as present participle tense is required.

Q105. The compound B formed in the sequence of reaction:

• A. Rropylene
• B. Propane
• C. Propene✓
• D. Propanol

Explanation: Alcohol reacts with PCl3 to form Alkyl Halides by nucleophilic substitution reaction forming akene (reaction shown below):

Q106. A mixture of 50gH 2 and 50g He has a total pressure of 1.5atm. what is the partial pressure of H2 gas:

• A. 1.0atm✓
• B. 2.0atm
• C. 1.5atm
• D. 3.0atm

Explanation: Find moles of hydrogen and helium; moles = mass/Mr; moles = 50/2 = 25 moles of hydrogen moles= 50/4 = 12.5 moles of helium Total moles = 12.5 + 25 = 37.5 moles Hence; Partial pressure of hydrogen = mole fraction x total pressure = 25/37.5 x 1.5 =1.0 atm (hence option A is the correct answer)

Q107. One hollow and one solid cylinder of the same radius are rolling down an inclined plane. Which of them will reach the end of the plane first?

• A. Solid cylinder✓
• B. Hollow cylinder
• C. Both simultaneously
• D. Depends upon the behavior among them

Explanation: mgcos∅ will get balanced by the normal force For rolling without slipping (pure rolling), we have a = àR ... (1) I am using symbol à for angular acceleration Two forces are acting, f and mgsin∅ submission of F =ma mg sin∅ -f= ma ... (2) (Here f is the friction force, a = linear acceleration à = angular acceleration) As we know, T= là (T=torque, I=inertia) from eqn(1)....à=a/R T=I(a/R) We know torque equals force into the radius But we also know the force of friction and radius are also perpendicular so T = f×R f×R = I ( a/R ) f =I ( a/R² ).......(3) From eqn (2) and (3), mgsin∅ - I ( a/R² ) =ma a = (mgsin∅) / (1/R²+m) a = (mgR²sin∅) / I+mR² m, R and ∅ are constant So, a is proportional to 1/I (I=inertia) The body whose inertia will less reach the bottom first We know, Inertia of solid cylinder = ½ mR² Inertia of hollow cylinder= ½ m ( R2² +R1²) I (solid) < I (hollow) So solid cylinder will have greater acceleration So, it will reach the end first

Q108. When an object slides at a constant speed down an inclined plane, the coefficient of friction may approximately be:

• A. sin∅
• B. Cos∅
• C. Tan∅✓
• D. cot∅

Explanation: We know,f =uN ………(1)where u=coefficient of kinetic frictionN = normal forceN =mg cos ∅ (as in the diagram, N balances mgcos∅)and f= mg sin∅ (as the body moves with constant speed, so f balances mgsin∅)Put these in eqn (1)mgsin∅=u×mgcos∅u =sin∅/cos∅u = tan∅

Q109. A particle was ejected from the nucleus of an atom in a radioactive decay and the active number of the atom increased. The particle was probably:

• A. A proton
• B. A neutron
• C. An alpha particle
• D. a beta particle✓

Explanation: Beta decay is a radioactive decay in which a beta ray is emitted from an atomic nucleus. The two types of beta decay are known as beta minus and beta plus. In beta minus (β−) decay, a neutron is converted to a proton, and the process creates an electron and an electron antineutrino; This causes an increase in atomic number by 1 with atomic mass unchanged while in beta plus (β+) decay, a proton is converted to a neutron and the process creates a positron and an electron neutrino. β+ decay is also known as positron emission. This causes a decrease in atomic number by 1 with atomic mass unchanged. Normally when they don't mention positive or negative beta decay, we always consider negative beta decay, increasing in atomic number by 1.

Q110. The ratio between mean life and half-life is:

• A. Log2
• B. 1/log λ
• C. 1/λ
• D. (Log2)-1✓

Explanation: We have to remember formulaMean life = 1/lambda Half life = log2 / lambda =log2 × 1/lambdaReplacing 1/lambda by mean life,Half life = log2 × mean life…….(i)Ratio required= mean life/ half lifeFrom equation (i)Mean life/half life = 1 / log2 = (log2)-¹

Q111. According to the postulates of the theory of relativity, a fourth dimension has been added to three dimensions already associated with the Cartesian frame of reference. Which is the fourth dimension?

• A. Space
• B. Inertial frame of reference
• C. Speed of light
• D. Time✓

Explanation: In Physics, a dimension can be defined as the magnitude of something in a particular direction. Everything that surrounds us is made up of three dimensions. These are known as three-dimensional or 3D objects. Before we look into the fourth dimension, first we need to understand the first three dimensions. The zero dimension For example, let’s take a sheet of paper. Place a dot on the paper. A dot does not have a direction or a magnitude. So, we can say that this dot does not have any dimensions. Let’s call this a zero dimension (0D). Image showing the first three dimensions for the geometry of the fourth dimension and the space-time continuum 0D, 1D, 2D, and 3D. The first dimension Next, from this dot, let’s draw a straight line along the x-axis. Now, we can measure the length of this line. So, we can say that this line has only one dimension. This is called a one-dimensional object or 1D. The second dimension Next, from this line, draw lines on both ends along the y-axis and convert this into a square. Now, for this square, we can measure both its length and width. As we can measure both its length and width, now we can say that this square has two dimensions. These are called two-dimensional or 2D objects. The third dimension Next, from this square, draw lines along the z-axis and convert this into a cube. Now, we can measure not only its length and width but also its height. As we can measure its length, width, and height, now we can say that this cube has three dimensions. These are called three-dimensional or 3D objects. Three-dimensional objects for the geometry of the fourth dimension and the space-time continuum 3D objects Similarly, objects that we see around us have length, width, and height making them three-dimensional. The fourth dimension and the space-time continuum In 1905, Albert Einstein published his Special theory of relativity which considers time as the fourth dimension. Let’s take a look at the cube again. As long as the cube is stationary, we can pinpoint its position along the x,y and z-axis. But, what if this cube starts moving? How can we pinpoint its exact position? To say the position of this moving object, Einstein introduced a dimension called “Time” into this 3D space. You may wonder how can “Time” be a dimension. For something to be a dimension, it must have a direction and a magnitude. Similarly, time can be measured (ex: seconds). And, time always flows in the forward direction. So, Einstein considered time as the fourth dimension. Now, with the help of time, we can pinpoint the exact location of this moving cube. Time for the fourth dimension and the space-time continuum Time is the fourth dimension.For example, we can say that at 8:00 am this cube was at a particular downward position (x,y,z) and at 9:00 am it was at an upward location (x,y,z) with the help of time. A:

Q112. Which of the following is a pair of conservative and non conservative forces?

• A. Gravitational forces and elastic forces✓
• B. Frictional force and propulsion of a motor
• C. electric force and tensioning string
• D. propulsion force of rocket and air resistence

Explanation: There are conservative and non-conservative forces. A conservative force is not path dependent, such as gravity and electrostatic forces. This means that the net work done by the force is only dependent on the initial and final positions if it is considered an outside force. If the system is defined so that a conservative force is doing work inside the system, such as an Earth and falling object system, the force only transforms the energy to a different form, but does not change the total energy of the system.

Q113. A constatnt force F is applied on a body of mass m for time interval t because of this force the velocity of body chnges from Vi to V. Then the changes in momentum during the interval 𐤃t will be?

• A. 1/2m( vf2 –vi2 )
• B. Δt/ma
• C. m(vf-vi)/Δ t✓
• D. Mass

Explanation: According to Newton's 2nd law F=ma Putting a= vf-vi/∆t F= m(vf-vi)/∆t Solving this ahead F=mvf-mvi /∆t we know Momentum = mv So mvf = final momentum mvi = initial momentum mvf-mvi = change in momentum mvf-mvi /∆t = change in momentum in interval ∆t

Q114. The efficiency of a Carnot engine that is operating between a cold reservoir at temperature Tc and a hot reservoir Th is dependent upon?

• A. The heat capacity of working substances
• B. Only the temperature of two reservoirs✓
• C. The reservoir temperature and the heat capacity of working substance
• D. The reservoir temperature and the volume chnage during heat absorption

Explanation: The Carnot engine is a theoretical thermodynamic cycle proposed by Nicolas Léonard Sadi Carnot in 1824. Carnot states that a hot body is required that generates heat and a cold body to which the caloric is conveyed, which produces mechanical work in the process.

Q115. Once the space shuttle is in orbit at a radius R from earths's centre what force does the seat exert on the astronout?

• A. mg
• B. Zero newton✓
• C. m/g
• D. mg/R2

Explanation: Zero. The force of gravity is counterbalanced by the force of angular acceleration.That’s how it stays in orbit.Have you ever seen any commentary on astronauts in spaceships? They are floating in a spaceship too, with no force.

Q116. Why do the rain drops fall with constant speed during the later stages of their journey?

• A. The air resistence just balances the force of gravity✓
• B. The force of gravity ois constant for all drops
• C. All drops fall from the same height
• D. The drops are small so force of gravity is negligible for them

Explanation: Terminal velocity, the steady speed achieved by an object freely falling through a gas or liquidLet's go into the imagination A raindrop falling through a ( air) ,When it just started falling, there was air resistance that was acting on itAs it continues its journey, air resistance increases until it becomes equal to the force of gravity Then the drop will have a constant speed and that speed is called terminal speed.Parachutes work on the same basis

Q117. If the area of a circle is equal to its circumstances tha radius os this circle is:

• A. 1
• B. 2✓
• C. 3
• D. 4

Explanation: Given,Area= circumference πr² = 2πrCutting π and r on both sidesr = 2

Q118. What is the current in a 2×106 ohms resistor having a potential difference of 6×10-3 volts?

• A. 1×10-3 A
• B. 2×10-3 A
• C. 3×10-3 A✓
• D. 4×10-3 A

Explanation: We know according to ohm's law.V=IRI = V/RPutting valuesWe get answer3×10-3 A

Q119. A particle moves along a straight line. The distance × described in time t is given by the equation x= t3 volts. The acceleration at t=1 is initial velocity =c:

• A. A=1✓
• B. B=2
• C. C=3
• D. D=4

Explanation: They just made the question confusing In fact it's very simple We have to find the velocity Distance is given as x=t³ Where t=1 So x=1 We know velocity is x/t Putting x=1 And t=1 We get velocity as 1 Which is option A

Q120. A 2N force acts on a mass. If the momentum of the mass changes by 120kg m/sec then the force acts for a time of:

• A. 8 sec
• B. 30 sec
• C. 60 sec✓
• D. 120 sec

Explanation: According to Newton's second law, Force is the rate of change of momentum i.e: F=∆p/∆t Since; F= 2NChange in momentum (∆p)= 120 kg m/sHence: ∆t = ∆p/F = 120/2 = 60 seconds

Q121. When a beam of light traveling in a rare medium is reflected from a denser medium it:

• A. Suffers no phase change
• B. Undergoes a phase change of 180° ·✓
• C. Undergoes a phase change of 270° ·
• D. Undergoes of 90°

Explanation: When light waves hit the boundary of a denser medium, some of it is transmitted/refracted and some is reflected. When a wave undergoes a reflection at a denser medium then its crest is reflected as a trough and vice versa. So its phase changes at 180 degrees or pi. Hence the correct option is B. The image given below is the summary of this concept:

Q122. What is the current in a 2× 106 ohms resistor having a potential difference of 6 x 103 volts?

• A. 1 ×10-3 A
• B. 2 ×10-3 A
• C. 3 ×10-3 A✓
• D. 4×10-3

Explanation: According to Ohm's Law V=IR Since V= 6x103 Volts R= 2 x 106 ohms Hence; I=V/R; I = 6x103 / 2x106 = 3x10-3 Ampere (so option C is the correct answer)

Q123. A 2N force acts on a mass. If the momentum of the mass changes by 120kg m /sec, then the force acts for a time of:

• A. 8 sec
• B. 30 sec
• C. 60 sec✓
• D. 120 sec

Explanation: According to Newton's second law, Force is the rate of change of momentum i.e: F=∆p/∆t Since; F= 2N Change in momentum (∆p)= 120 kg m/s Hence: ∆t = ∆p/F = 120/2 = 60 seconds

Q124. When a beam of light travleing in a rare medium is reflected from a denser medium it:

• A. Suffers no phase change
• B. Undergoes a phase change of 180°✓
• C. Undergoes a phase change of 270°
• D. Undergoes a phase change of 90°

Explanation: When light waves hit the boundary of a denser medium, some of it is transmitted/refracted and some is reflected. When a wave undergoes a reflection at a denser medium then its crest is reflected as a trough and vice versa. So its phase changes at 180 degrees or pi. Hence the correct option is B. The image given below is the summary of this concept:

Q125. A piece of wood and a piece of iron seem to lose the same weight when completely submerged in a liquid. The two pieces must have the same:

• A. Weight in water
• B. Weight in liquid
• C. Weight in air
• D. Volume✓

Explanation: According to the Archimedes principle, if an object is immersed in a fluid, it experiences an apparent loss of weight which is equal to the weight of the fluid displaced. The buoyant force which acts in the upward direction opposite to the weight of the object causes the apparent loss in weight. In the air, the buoyant force is negligible. Hence, the object seems heavier compared to when it is submerged. As the two objects undergo the same loss of weight when submerged in water then they must displace the same volume of water. Consequently when the objects are in the air then they will also displace the same amount of air, and as a result, they will also lose the same amount of weight as each other in the air. The weight of the objects themselves is different due to different densities in air as well as in water but the volume of liquid displaced would be the same.

Q126. If the speed of sound in air is 340 m/sec. What is the wavelength of a 1-KHz sound wave?

• A. 3.40m
• B. 2.94m
• C. 0.340m✓
• D. 0.294m

Explanation: According to the v=fλ v= 340m/s f= 1 x 103 Hz Hence λ= v/f = 340 / 1x103= 0.34 m (option C is the correct option)

Q127. Which type of electromagnetic radiation has the longest wavelength?

• A. Gamma rays
• B. UV
• C. Microwave✓
• D. X-rays

Explanation: In the given electromagnetic spectrum it can be seen that wavelength increases from gamma rays towards radio waves and frequency decreases. Hence among gamma rays, x-rays, UV radiations and radio waves, RADIO WAVES have the longest wavelength (hence the answer is C).

Q128. In order to change the momentum of an objective there must be:

• A. A force applied✓
• B. A change in time
• C. A change in distance
• D. A change in temperature

Explanation: Fact. According to Newton's second law of motion, force is the rate of change of momentum i.e: F = d p/dt And hence a force acting for a given amount of time will change an object's momentum. Put another way, an unbalanced force always accelerates an object - either speeding it up or slowing it down.

Q129. The force of one newton per meter square is equal to:

• A. bar
• B. atm
• C. Pascal✓
• D. erg

Explanation: Fact. According to the formula Pressure=Force/Area 1 N/m2 = 1 Pascal

Q130. While determining the expression for time period of simple pendulum, we keep the amplitude:

• A. Large
• B. Small✓
• C. Maximum
• D. Zero

Explanation: If we consider a pendulum, we can see simple harmonic motion in it. According to the formula T = 2π √L/g , where L is the length of the string in the pendulum and T is its time period, Time period does not depend on amplitude. So if the amplitude value is kept small, then the oscillations are smooth as the time period is independent of amplitude. Amplitude must be small because the "time period does not depend on amplitude" rule applies to pendulums only if it is exhibiting simple harmonic motion.

Q131. An ocean wave has an amplitude of 2.5m weather condition suddenly changes such that the wave has an amplitude of 5.0m the amount of energy transported by the is;

• A. Halved
• B. Doubled
• C. Quadrupled✓
• D. Remain the same

Explanation: The correct option is C Quadrupled. The energy transported by a wave is directly proportional to the square of the amplitude of the wave. This energy-amplitude relationship is sometimes expressed in the following manner. This means that a doubling of the amplitude of a wave is indicative of a quadrupling of the energy transported by the wave. A tripling of the amplitude of a wave is indicative of a nine-fold increase in the amount of energy transported by the wave. And a quadrupling of the amplitude of a wave is indicative of a 16-fold increase in the amount of energy transported by the wave. The table below further expresses this energy-amplitude relationship. Observe that whenever the amplitude increases by a given factor, the energy value is increased by the same factor squared. For example, changing the amplitude from 1 unit to 2 units represents a 2-fold increase in the amplitude and is accompanied by a 4-fold (22) increase in the energy; thus 2 units of energy becomes 4 times bigger - 8 units. As another example, changing the amplitude from 1 unit to 4 units represents a 4-fold increase in the amplitude and is accompanied by a 16-fold (42) increase in the energy; thus 2 units of energy becomes 16 times bigger - 32 units.

Q132. When a generator is being driven at 1200rpm, the generated eml is 130 volts. What is the generated emf, if the speed is reduced to 600rpm, while the field flux remains unchanged?

• A. 65V✓
• B. 260V
• C. 60V
• D. 10V

Explanation: We know that generated EMF in the DC generator is given by the formula: E = ΦPNZ/60A Where Φ= flux P= No. of poles N= speed Z= No. of conductors A= No. of paths Hence E ∝ ΦN E2/E1 = Φ2/Φ1 X N2/N1 ~since field flux remains unchanged hence it will be cancelled and so: E2/E1 = N2/N1 E2/130 = 600/1200 E2= 65 V (hence it is the generated emf)

Q133. A girl sitting on a spinning bar tool with her legs folded, suddenly out spreads her angular velocity will:

• A. Decrease✓
• B. Increase
• C. Remain the same
• D. First increase and then decrease

Explanation: According to conservation of Angular Momentum, Iω = constant Hence, when the girl sitting on a bar stool suddenly spreads her hands, then her angular velocity will decrease and moment of inertia will increase.

Q134. When longitudinal waves propagate through a medium, the particles of the medium:

• A. Vibrate parallel to the direction of propagation of waves✓
• B. Vibrate perpendicular in to the direction of propagation of waves
• C. Do not move at all
• D. Vibrate at an angle of 360° to the direction of waves

Explanation: Fact. In longitudinal waves the movement of the particle is along the direction of the wave i.e the movement of particles is usually parallel to the movement of energy. Whereas in transverse waves the movement of the particle is perpendicular to the direction of the wave i.e the particles are displaced perpendicular to the direction of the traveling wave.

Q135. In the absence of an external torque, the angular momentum of a rotating body is:

• A. Constant✓
• B. Variable
• C. Unstable
• D. Zero

Explanation: Fact. In the absence of an external torque, angular momentum is conserved: More formally, the total angular momentum of a rotating object remains constant if the net external torque acting on it is zero.

Q136. A lamp is connected to a 12-volt battery. An ammeter indicates a current of 5 mps. The watt of the lamp is:

• A. 2.4 watts
• B. 120 watts
• C. 60 watts✓
• D. 300 watts

Explanation: The question is asking for the watt or power of the lamp. We know that P = IV and we are given that I = 5 amps and V = 12 volts. P = 5x12 P = 60 W Therefore, C is the correct answer

Q137. An object is placed at a distance of 6cm from a lens that has focal length of 4 cm where is the image located:

• A. 10 cm
• B. 12 cm✓
• C. 14 cm
• D. 16 cm

Explanation: We know the formula 1/f = 1/v - 1/u, where f = focal length of lens, v = distance of image from lens & u = distance of object from lens Rearranging the equation we get, 1/v = 1/f + 1/u We’re given that f = 4cm and u = -6cm (-6 since the object is on the left of the lens and the image will form on the right). Plugging in the values we get 1/v = ¼ - ⅙ 1/v = 1/12 v = 12 cm Therefore, B is the correct answer.

Q138. When temperature of a radioactive substance is changed the radiation emitted will:

• A. Increase
• B. Remain the same✓
• C. Decrease
• D. Increase or decrease depending upon the temperature of the substance

Explanation: Radioactivity is always random and spontaneous. Random means one cannot know precisely when the next decay will happen, though one can predict the probability of such events occurring in some time interval. Spontaneous means that the radiation emitted does not require any outside influence or stimulation to occur i.e. radiation emitted is independent of the physical conditions e.g. temperature. A) Changing the temperature will not increase the radiation emitted since radioactivity is always spontaneous. B) Changing the temperature will keep the radiation emitted the same since radioactivity is always spontaneous. C) Changing the temperature will not decrease the radiation emitted since radioactivity is always spontaneous. D) Changing the temperature will not increase or decrease the radiation emitted depending on the change of temperature since radioactivity is always spontaneous. Therefore, the correct answer is B

Q139. If the stay of 6 men for 14 days in a hotel costs Rs.3360, find the cost for stay of 4 men for 7 days in the same hotel?

• A. 823
• B. 1120✓
• C. 1372
• D. 2520

Explanation: In the question, we are given that it costs Rs. 3360 for 6 men to stay at a hotel for 14 days. We would like to find out the cost of staying at the hotel for one man for one day. If 6 men were to stay at the hotel for one day, the cost would be 3360 / 14 = Rs. 240. If 1 man was to stay at the hotel for one day, the cost would then be 240/6 = Rs. 40. We now know that the cost to stay at the hotel is Rs. 40 per day per person. To find the total cost for 4 men staying for 7 days, we multiply these numbers by the cost to stay at the hotel per day per person. 40x4x7 = Rs. 1120. Therefore B is the correct answer.

Q140. The waves which do not require any medium for their propagation are called:

• A. Mechanical waves
• B. Sound waves
• C. Tidal waves
• D. Electromagnetic waves✓

Explanation: Waves that do not require any medium for their propagation are called electromagnetic waves.

Q141. The energy carried by water waves is proportional to the:

• A. Wavelength squared
• B. Amplitude squared✓
• C. Square root of the wavelength
• D. Square root of the amplitude

Explanation: Water is a transverse mechanical wave so we know that the power and energy carried by the wave is directly proportional to the square of the amplitude. A) The energy carried by water waves is independent of the square of the wavelength. B) The energy carried by water waves is directly proportional to the square of the amplitude. C) The energy carried by water waves is independent of the square root of the wavelength. D) The energy carried by water waves is directly proportional to the square of the amplitude, not the square root. Therefore, B is the correct answer.

Q142. A cyclist moves a distance of 4km toward east and then a dostance of 3km towards north. How far is he from the starting point?

• A. 3km
• B. 9km
• C. 7km
• D. 5km✓

Explanation: We have to find the displacement of the cyclist from the initial position. He moves 4km east (to the right) and 3km north (upwards). Since both directions are at 90 degrees to each other, a right triangle is formed (see diagram below). Using the Pythagorean theorem, you can find the third side by x = sqrt(42 + 32) = 5. Hence, the answer is D.

Q143. The process in which a system undergoes a change of state at constant volume is called:

• A. Isothermal
• B. Isochronic✓
• C. Adiabatic
• D. Isobaric

Explanation: Isochronic or isochoric processes are carried out at constant volume.

Q144. Which one of the following will produce a pink colour in a discharge tube?

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

Explanation: A tube containing charged electrodes and filled with a gas in which ionization is induced by an electric field. The gas molecules emit light as they return to the ground state. Each gas has a characteristic colour in the discharge tube, shown in the figure below. A) Neon has a red colour in the discharge tube. B) Nitrogen has a purple colour in the discharge tube. C) Helium has a pink colour in the discharge tube. D) Oxygen has a violet colour in the discharge tube. Therefore, C is the correct answer since He has a pink colour in the discharge tube.

Q145. A force of 2000 dynes is applied to a mass of 250gm. What acceleration would be obtained?

• A. 25
• B. 20
• C. 16
• D. 8✓

Explanation: We have to use Newton’s second law, F = ma, in this question. Usually, we use SI units, i.e. Newtons for Force, Kilograms for Mass and m/s2 for acceleration. However, there are an alternative set of units for Newton’s second law which is Dynes (1 Newton = 100000 Dynes) for Force, grams for mass and cm/s2 for acceleration. Hence, in this question, to find acceleration in cm/s2 we use a = F/m = 2000/250 = 8 cm/s2. Hence, D is the correct answer.

Q146. Diver curls his bosy when diving so that he can perform some quick somersaults. This is because:

• A. His angular momentum increases
• B. His effective radius increases
• C. his angular momentum decreases
• D. his angular velocity increases✓

Explanation: A) By the law of conservation of angular momentum, the total angular momentum of the diver will stay the same irrespective of the way the diver curls his body. Therefore, A is incorrect since his angular momentum cannot increase. B) When the diver is curling his body, you can think of him as trying to form a tighter, smaller circle. Since the imaginary circle’s size is decreasing, the effective radius of the will also decreases, so B is incorrect. C) By the law of conservation of angular momentum, the total angular momentum of the diver will stay the same irrespective of the way the diver curls his body. Therefore, C is incorrect since his angular momentum cannot decrease. D) By elimination, D must be correct. Since the diver is performing somersaults faster, he is rotating around the circle faster. Therefore, his speed while rotating around the circle (i.e. the angular speed) increases, so D is the correct answer.

Q147. If two electrons are passing across a point in 2 seconds then the current following will be:

• A. One ampere
• B. Two ampere
• C. 1.6x 10+19 amperes
• D. 1.6x 10-19 amperes✓

Explanation: I = Q/t = Ne/t = 2 x 1.6 x 10-19 / 2 = 1.6 x 10-19 A. Therefore, D is the correct answer.

Q148. If two electrons are passing across a point in 2 seconds then the current following will be :

• A. One ampere
• B. Two ampere
• C. 1.6x 10+19 amperes
• D. 1.6x 10-19 amperes✓

Explanation: I = Q/t = Ne/t = 2 x 1.6 x 10-19 / 2 = 1.6 x 10-19 A. Therefore, D is the correct answer.

Q149. Two forces having magnitude 3.5N and 5.5N are acting on a body. Which one of the following can not be the resultant of their possible sum:

• A. 1.5N✓
• B. 2.5N
• C. 4.5N
• D. 6.5N

Explanation: Since there are 2 forces, the minimum resultant force is when they are pointing in opposite directions i.e. they are at 180° to each other. In this case, the resultant force will be 5.5 – 3.5 = 2N. For the maximum resultant force, both forces must be pointing in the same direction i.e. 0° between each other. In this case, the resultant force will be 5.5 + 3.5 = 9N. Therefore, at any angle, the resultant force R will always be 2 ≤ R ≤ 9. Hence, A is correct since it falls outside this range.

Q150. If sum of the two numbers is-9 and their product is-36, then the numbers are:

• A. 12, -3
• B. -12, 3✓
• C. -12, -3
• D. 9, -4

Explanation: Instead of forming two simultaneous equations (a + b = -3 & ab = -36) and solving them, it is often advantageous and time efficient to quickly scan the answers and see which ones fit the given requirements. In this case, only answer B meets the initial condition that a+b = -3 and 3x-12 = -36 too, so B is the correct answer.

Q151. The angle subtended by the circumference of a circle at its centre:

• A. 2π radians✓
• B. π radians
• C. 270 degrees
• D. 180 degrees

Explanation: The circumference covers the entire length of the circle, so the angle subtended by it must be equal to the maximum angle in the circle, i.e. 2π radians or 360°. Therefore, A is the correct answer.

Q152. Which one of the following must be decreased in order to increase the capacitance of a capacitor?

• A. The area of the plates
• B. The distance between the plates✓
• C. The number of the plates
• D. The dielectric constant

Explanation: The formula for capacitance is C = εo εr A/d. Decreasing the distance between the plates would increase the capacitance since C is inversely proportional to d. Therefore, B is correct.

Q153. The change of magnetic flux through a circuit will produce:

• A. Magnetic field✓
• B. Electric field
• C. Induced emf
• D. Altemating current

Explanation: Protip: Static/ not moving charge: electric field Charge moving with constant velocity: electric and magnetic field

Q154. A Solenid is formed by winding:

• A. Wire in a helix around a box
• B. Wire in a helix around a cylindrical surface✓
• C. Wire in a helix on a plain surface
• D. Cannot be made using wire

Explanation: A solenoid is an instrument that consists of copper coiling over a cylinder designed to create a strong magnetic field inside the coil because of the flow of current through the coil. By wrapping the same wire many times around a cylinder, the magnetic field due to the flow of current can become quite strong.

Q155. The phenomenon in which electron and positron are converted into two photons, is called:

• A. Pair production
• B. Compton effect
• C. Annihilation of matter✓
• D. photoelectric effect

Explanation: A.The creation of an elementary particle and its antiparticle, usually when a photon (or another neutral boson) interacts with a nucleus an electron and its antiparticle, the positron, may be created is called pair production B. The scattering of high frequency photon strikes a stationary electron the frequency of the photon is decreased after the collision. This phenomenon is referred to as Compton's effect. C. When an electron(e-) and a positron(e+) collide two gamma-ray photons are produced and the phenomenon is called pair annihilation D. When light hits the metal surface electrons are emitted, the phenomenon is called the photoelectric effect and the electrons emitted are called photo-electrons.

Q156. If kinetic energy of a body is increased by 300% then % increase in momentum is:

• A. 300%
• B. 100%✓
• C. 50%
• D. 200%

Explanation: Let kinetic energy = E and momentum = pE=p²/2m Let initial kinetic energy, E1=EFinal kinetic energy. E2=E+300As p ∞√E⇒p2/p1=√E2/E1=√4E/E=2⇒p2=2p1⇒p2=p1+100i.e. Momentum will increase by 100%

Q157. When a solid is heated, which of the following changes occur?

• A. The density increases
• B. The latent heat increases
• C. The molecule vibrates more rapidly✓
• D. The melting point increases

Explanation: The changes that take place when a solid is heated (increase in temperature) are as follows:On increasing the temperature of solids, the Kinetic Energy (K.E.) of particles increases.Due to an increase in Kinetic Energy(K.E.), the particles start vibrating with greater speed.The energy supplied by heat overcomes the force of attraction between the particles.Then, the particles leave their fixed positions and start moving freely, and thus solid melts.Thus melting of solids takes place.Melting or Fusion: The process due to which a solid change into a liquid state by absorbing heat energy is called melting or fusion.

Q158. The wavelength,of last spectral line in Lyman series in terms of Rydberg constant(R) is equal to:

• A. R
• B. R2
• C. 1/R✓
• D. 1/R2

Explanation: Answer;B (should be C) Wave number = 1/lambda = R(1/nf² - 1/ni²) Where nf is the final shell of the electron and ni is the initial shell of the electron. For the last line, the electron must be coming from infinity so 1/ni²= 1/infinity =0 nf=1 as it is the Lymann series 1/lambda= R (1/1) Lambda = 1/R

Q159. A write of length 1 m is carrying a current of 2A and is held perpendicular to a magnetic field of 0.5 tesla. it will experience a force of:

• A. 1N✓
• B. 1/2 N
• C. 1/3 N
• D. 1/4 N

Explanation: Answer; B (Answer should be A) F=BILsintheta theta= 90° F= 0.5× 2× 1× sin90 = 1 N

Q160. The conduction due to charges produced by pair generation in a semi Conductor is called:

• A. Polarity
• B. Intrinsic conduction✓
• C. Electrostatic
• D. Amplitude modulation

Explanation: Answer (should be B)A: Such a word not foundPolarity: the property of having poles or being polarB: An intrinsic semiconductor, also called an undoped semiconductor or i-type semiconductor, is a pure semiconductor without any significant dopant species present. The number of charge carriers is therefore determined by the properties of the material itself instead of the amount of impurities.Each electron that moves to the conduction band, leaves behind a vacant position or hole in the valence band, (i.e. an unoccupied electron position in the covalent bond that it "escaped" from). This process is called electron-hole pair generation.When an electric field is applied across an intrinsic semiconductor, the current conduction takes place through two processes, free electrons and holes.C: Electrostatic: relating to stationary electric charges or fields as opposed to electric currents.D: Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave

Q161. Number of electric lines of force passing throug a certain area is known as:

• A. Electric field
• B. Electric flux✓
• C. Electric intensity
• D. Gravitational field

Explanation: SHOULD be B)A: An electric field is defined as any region around a charge in which an electric test charge would experience an electric force B: Electric Flux is the measure of the number of lines of force that pass through an area in an electric field.C: The intensity of an electric field at any point is the force per unit positive test charge placed at a pointD: Gravitational field is the field of force surrounding a body of finite mass in which another body would experience an attractive force that is proportional to the product of the masses and inversely proportional to the square of the distance between them