Federal Mdcat Mock Paper 2 — Solved Past Paper with Answers

Q1. Identify the word or phrase that needs to be changed for the sentence to be correct: The stories that she makes out for her children ought to be written down and published.

• A. That
• B. Makes out✓
• C. Ought to
• D. Written down
• E. No error

Explanation: The correct statement should be, with the correct preposition: The stories that she makes “for”.

Q2. Identify the word or phrase that needs to be changed for the sentence to be correct. You cannot leave now. The lions and tigers will appear in a minute. No error

• A. You
• B. The lions
• C. Tigers
• D. Appear
• E. No error✓

Explanation: In questions where you have to find the errors, read the given sentence at least twice. Then focus on the underlined parts to see which part has error in it. In the given sentence there is no error.

Q3. Choose the correct sentence from the following options:

• A. The government should accrue taxes for strengthen the economy of the country.
• B. The government should accrue taxes in strengthen the economy of the country
• C. The government should accrue taxes to strengthen the economy of the country.✓
• D. The government should accrue taxes by strengthen the economy of the country.

Explanation: By comparing all four sentences ,you notice there is only one difference i.e. PREPOSITION and for fact the best suited is 'to strengthen'.

Q4. In each of the following questions, four alternative sentences are given.Choose the CORRECT option.

• A. Norma had put the button unit besides her on the couch.
• B. Norma put an button unit besides her on the couch.
• C. Norma put the button unit besides hers on the couch.
• D. Norma put the button unit beside her on the couch.✓

Explanation: The phrase "beside her" is used in the sentence to indicate the location of the button unit in relation to Norma. "Beside" means next to or by the side of someone or something. In this case, it suggests that Norma placed the button unit in close proximity to herself, likely on the couch within reach. The phrase provides spatial information and helps to specify the position of the button unit in relation to Norma.

Q5. Each sentence below has a blank indicating that something has been omitted. Choose the word that best fits in with the meaning of the sentence as a whole.The provost was utterly _ about having the students keep their books tidily in their lockers, yet her desk was very _.

• A. Apathetic ...comfortable
• B. Bewildered ... bizarre
• C. Determined ...disorderly✓
• D. Considerate...modern

Explanation: The words that best fit the sentence are Determined ... disorderly.Determined fits because it describes someone who is firm or resolute about having students keep their books tidily.Disorderly fits because it describes the messy state of the provost's desk, contrasting with her expectations for tidiness from others.In this sentence, the provost is portrayed as having a strong expectation or insistence (determined) that students keep their books tidy. However, the state of her desk is described as disorderly, which contrasts sharply with her expectations. This choice accurately reflects the intended meaning of the sentence, highlighting the irony or contrast between her expectations and her own desk's state.

Q6. Each sentence below has a blank indicating that something has been omitted. Choose the word that best fits in with the meaning of the sentence as a whole.The air in a room that contains several houseplants can be more _ oxygen than in a room that contains no plants.

• A. Complicated by
• B. Exhausted with
• C. Obscured by
• D. Saturated with✓

Explanation: The word that best fits the sentence is Saturated with.Saturated with accurately describes a room where the air contains a higher concentration of oxygen, enhanced by the presence of several houseplants.In this sentence, "saturated with" effectively communicates that the air in a room with houseplants has a higher concentration of oxygen. Houseplants release oxygen as a byproduct of photosynthesis, thereby increasing oxygen levels in indoor environments. This choice accurately reflects the intended meaning of the sentence, emphasizing the beneficial effect of houseplants on indoor air quality.

Q7. In the following questions, sentences are given with blanks to be filled in with an appropriate word. Four alternatives are suggested for each question. Choose the correct alternative, out of the four as your answer. Ravens appear to behave _, actively helping one another to find food.

• A. mysteriously
• B. warily
• C. aggressively
• D. defensively✓

Explanation: Option D is the correct answer because this sentence asks you to look for a word that describes how the ravens behave. The information after the comma restates and defines the meaning of the missing word.

Q8. Select the option which fits appropriately in the blank: My father often _ here.

• A. Come
• B. Came
• C. Comes✓
• D. Coming

Explanation: 'Comes' is the singular present tense of the word 'come' so it will be used here as the father is coming to the location presently.

Q9. Select the option which fits appropriately in the blank: I am in London this Summer, I _ English.

• A. Learn
• B. Learns
• C. Am learning✓
• D. Learning

Explanation: Since the sentence is in continuous and present tense, the verb will have '-ing' added so it will end up as 'am learning'.

Q10. Select the option which fits appropriately in the blank: A really sophisticated person would never be _ enough, to think that he is always right.

• A. Reverent
• B. Naive✓
• C. Articulate
• D. Humble

Explanation: If someone always thinks they’re right, that is foolish on their behalf, therefore it would be 'naive' for a sophisticated person.

Q11. Select the option which fits appropriately in the blank: Everyone _ done his or her homework.

• A. Has✓
• B. Have
• C. Had
• D. Non

Explanation: The indefinite pronouns anyone, everyone, someone, no one, nobody are always singular and, therefore, require 'singular verbs'. Everyone has done his or her homework.

Q12. Jack is six years old, but he _ French and Spanish.

• A. Speaking
• B. Is speaking
• C. Speaks✓
• D. Speak

Explanation: Correct answer is C Option C is correct because the given sentence is in the present simple tense, and "speaks" is the correct verb form for the third-person singular subject

Q13. Select the most suitable synonym for the given word:FECKLESS:

• A. Useless
• B. Careless✓
• C. Dauntless
• D. Fearless

Explanation: Feckless means to be careless

Q14. Select the most suitable synonym for the given word:JUXTAPOSE:

• A. Justify
• B. Compare✓
• C. Expos
• D. Jettison

Explanation: Juxtapose means to compare two contrasting things/traits.

Q15. Which one is grammatically correct? Read carefully.

• A. Both are correct
• B. Speak up! I can't hear you because your dog is making too much noise.✓
• C. Both are wrong
• D. Speak up! I can't hear you because your dog is making much too noise.

Explanation: Too much is used as a determiner with singular (uncountable) nouns while much too is used with comparatives and adjectives. As noise is a noun, therefore too much noise is grammatically correct.

Q16. Choose the related word for Rat on the analogy of Elephant : Stride.

• A. Scamper✓
• B. Loiter
• C. Whimper
• D. Gallop

Explanation: small animal running with quick light steps

Q17. A person who leaves his country and settles in another country is called:

• A. Emigrant✓
• B. Immigrant
• C. Migrant
• D. Aborigine

Explanation: immigrant is used in reference to the country moved to, and emigrant is used in reference to the country moved from

Q18. Choose the correct spelling of the word:

• A. Something✓
• B. Somthing
• C. Sumthing
• D. Sumthin

Explanation: The correct spelling is 'something'.

Q19. Detoxification of drugs is the function of _ in a cell.

• A. R.E.R
• B. S.E.R✓
• C. Liver cells
• D. Lysosome

Explanation: The smooth endoplasmic reticulum is a part of the endoplasmic reticulum which does not possess ribosomes studded on its membrane. It is involved in the detoxification of many poisons and drugs such as lipid soluble drugs, aspirin, insecticides (DDT), petroleum products and pollutants and converting them to safer water-soluble products.

Q20. Holoenzyme is?

• A. Protein moiety of enzyme
• B. Non-protein moiety of enzyme
• C. Complete enzyme✓
• D. Inactive enzyme

Explanation: Holoenzyme is a complete, functional enzyme, which is catalytically active. It consists of an Apoenzyme and a Cofactor. In order to be functional, an apoenzyme(inactive enzyme) needs to become a holoenzyme(active enzyme). FTB page# 62

Q21. A non­-proteinaceous enzyme is:

• A. Lysozyme
• B. Ribozyme✓
• C. Ligase
• D. Deoxyribonuclease

Explanation: A ribozyme is a ribonucleic acid (RNA) enzyme that catalyzes a chemical reaction similarly to that of a protein enzyme. These are found in ribosomes and are also called catalytic RNAs.

Q22. Which of the following is the least likely to be involved in stabilizing the three­ dimensional folding of most proteins?

• A. Hydrogen Bonds
• B. Electrostatic Interaction
• C. Hydrophobic Interaction
• D. Ester Bonds✓

Explanation: Protein folding is the process by which a protein structure assumes its functional shape or conformation by allowing interaction between amino acids by various bond formations. All protein molecules are heterogeneous unbranched chains of amino acids. Different types of weak interactions hold the interacting segments together in protein. Hydrophobic interaction, H bonds, and electrostatic interactions are the weak ones and stabilize the tertiary structure of proteins, while ester bonds are covalent bonds and are least likely to be involved in stabilizing the three-dimensional folding of most proteins.

Q23. In which type of cells, cell wall is not present?

• A. Plant cells
• B. Fungal cells
• C. Bacterial cells
• D. Liver cells✓

Explanation: A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism. No cells in the human body have a cell wall, hence liver cells will not have one either. Plant cell walls are primarily made of cellulose, which is the most abundant macromolecule on Earth. The cell wall is a characteristic structure of fungi and is composed mainly of glucans, chitin, and glycoproteins. The bacterial cell wall consists of peptidoglycan, an essential protective barrier for bacterial cells that encapsulates the cytoplasmic membrane

Q24. The diagram is taken from an electron of a cell, name the organelle labeled D:

• A. Nucleus
• B. Lysosomes
• C. Golgi complex
• D. Mitochondria✓
• E. Endoplasmic reticulum

Explanation: Mitochondria are bean- shaped membrane bounded organelles. Cristae is the fold in the inner membrane of mitochondria which is visible in the picture.

Q25. In which of the following is the organic compound COOH (carboxyl) group found? (I) Carbohydrate (II) Lipid (III) Protein

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

Explanation: Carboxyl groups are commonly found in amino acids, fatty acids, and other biomolecules. Whereas carbohydrates only contain atoms of carbon hydrogen and oxygen they don't have any functional group.

Q26. A disease caused by an autosomal primary non-disjunction is:

• A. Klinefelter’s syndrome
• B. Turner’s syndrome
• C. Sickle cell anaemia
• D. Down’s syndrome✓

Explanation: Down's syndrome is caused due to the trisomy of 21 chromosome which is an autosome. It is mainly caused due to the non-disjunction of the chromosomes. Non-disjunction is the condition when the sister chromatids fails to seperate during the cell division.

Q27. The mechanism that causes a gene to move from one linkage group to another is called:

• A. Inversion
• B. Duplication
• C. Translocation✓
• D. Crossing­ over

Explanation: Translocation is a chromosomal abnormality caused by the rearrangement of parts between non­-homologous chromosomes. It may cause a gene to move from one linkage group to another.

Q28. In the following human pedigree, the filled symbols represent the affected individuals. Identify the type of given pedigree.

• A. Autosomal recessive✓
• B. X-­linked dominant
• C. Autosomal dominant
• D. X-­linked recessive

Explanation: Autosomal recessive traits are the traits which are caused by recessive autosomal genes when present in homozygous condition. The given pedigree can be explained as:As the trait appears only in homozygous recessive individuals (aa), therefore it is an autosomal recessive trait.

Q29. The area on the left hemisphere related to speech is called?

• A. Amygdala
• B. Broca's area✓
• C. Hypothalamus
• D. Occipital lobe

Explanation: Option A: The amygdala is commonly thought to form the core of a neural system for processing fearful and threatening stimuli (4), including detection of threat and activation of appropriate fear-related behaviors in response to threatening or dangerous stimuliOption B: Broca’s area is also known as the motor speech area. It is near the motor cortex and utilized in speech production, located in the inferior frontal gyrus. This area regulates breathing patterns while speaking and vocalizations required for normal speech.Option C: Hypothalamus is ,a structure deep in your brain, acts as your body's smart control coordinating center. Its main function is to keep your body in a stable state called homeostasis. It does its job by directly influencing your autonomic nervous system or by managing hormonesOption D: The occipital lobes sit at the back of the head and are responsible for visual perception, including colour, form and motion. Damage to the occipital lobe can include: Difficulty with locating objects in environment

Q30. The diencephalon comprises of:

• A. Pons of medulla
• B. Thalamus and limbic system✓
• C. Pons and medulla
• D. Hypothalamus and limb

Explanation: The diencephalon is a part of the brain that is located between the cerebrum and the midbrain. It is made up of four main parts: a) thalamus b) hypothalamus c) epithalamus d) subthalamus Hypothalamus is also a part of the limbic system.

Q31. The primary electron acceptor in cyclic photophosphorylation is:

• A. Carbon dioxide
• B. A protein that contains iron and sulphur✓
• C. NADP
• D. FAD

Explanation: The electron released by P700 in the presence of light is passed to the primary acceptor, ferredoxin, then plastoquinone, cytochrome complex, plastocyanin, and finally back to P700. Ferredoxins are small proteins containing iron and sulphur atoms organised as iron–sulphur clusters. Therefore, the correct answer is B.

Q32. A woman with normal colour vision, whose father was red green colour blind, married a red green colour blind man. What is the probability of her born child being red green colour blind?

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

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

Q33. Gigantism in human beings is caused due to over secretion of:

• A. Thyrotropin
• B. Corticotropin
• C. Somatotropin✓
• D. Prolactin

Explanation: Gigantism occurs when a child’s pituitary gland makes too much growth hormone, which is also known as somatotropin. Corticotropin-releasing hormone (CRH), also called corticotropin-releasing factor (CRF), is a peptide hormone that activates the synthesis and release of adrenocorticotropic hormone (ACTH) from the pituitary gland. In this way, CRH affects our response to stress, addiction and depression, amongst others. Prolactin is a hormone made by the pituitary gland, a small gland at the base of the brain. Prolactin causes the breasts to grow and make milk during pregnancy and after birth. Thyroid-stimulating hormone/Thyrotropin is a hormone produced by anterior pituitary gland that stimulates the thyroid gland to produce thyroxine, and then triiodothyronine which stimulates the metabolism of almost every tissue in the body. Therefore, the correct answer is C.

Q34. A structure established between the uterine and foetal tissues for the exchange of oxygen, carbon dioxide, waste, nutrients and other materials is:

• A. Amnion
• B. Placenta✓
• C. Endometrium
• D. Uterus

Explanation: The placenta is defined as temporary intimate mechanical and the physiological connection between foetus and maternal tissue for the nutrition, respiration and excretion of the foetus. Human placenta consists of chorion only. The placenta is fully formed by the end of the third month and maintains pregnancy. In the placenta, the foetal blood comes very close to the maternal blood and this permits the exchange of material between the two. Food, water, mineral salt, vitamins, hormone antibodies and oxygen pass from the maternal blood into the foetal blood, and foetal metabolic waste, such as carbon dioxide, and urea, also water and hormones, pass into the maternal blood.

Q35. All of the following statements about arteries are true except:

• A. They are thick-walled
• B. They pulsate
• C. They contain much elastic fiber tissue
• D. They carry blood away from the heart
• E. They contain valves✓

Explanation: Unlike arteries, veins contain valves that ensure blood flows in only one direction. (Arteries don't require valves because pressure from the heart is so strong that blood is only able to flow in one direction.)

Q36. The rate of breathing is controlled by the:

• A. Lungs
• B. Cerebellum
• C. Pons
• D. Medulla oblongata✓
• E. Diaphragm

Explanation: The respiratory center is located in the medulla oblongata and is involved in the minute-to-minute control of breathing.

Q37. The joints that allow movement in two directions are called:

• A. Ball and Socket joint
• B. Hinge joint✓
• C. Cartilaginous joint
• D. Fibrous joint

Explanation: Hinge joints are the ones that allow the movement in only 2 directions. Elbow and knee joints are the examples of hinge joints.

Q38. _ accepts hydrogen from malate

• A. COQ
• B. FMN
• C. FAD
• D. NAD✓

Explanation: Oxidation(Dehydrogenation -IV) is one of the steps of Krebs cycle, in which Malate is oxidized by removal of hydrogen and oxalo-acetate gets regenerated. The hydrogen removed in this reaction is taken up by the coenzyme NAD to form NADH2.

Q39. The absorption and use of calcium are regulated by

• A. Parathormone✓
• B. Adrenaline
• C. Thyroxin
• D. Thiamin
• E. Prolactin

Explanation: Circulating parathyroid hormone targets the distal convoluted tubule and collecting duct, directly increasing calcium reabsorption.

Q40. Enzymes that are functioning within the cell are called:

• A. Endoenzymes✓
• B. Exoenzymes
• C. Holoenzymes
• D. Both A & C

Explanation: Endoenzymes are enzymes that act within the cell, and their catalytic activity is confined to the interior of the cell. They are involved in intracellular processes, catalyzing reactions within the cell's cytoplasm or organelles. Enzymes involved in glycolysis, the Krebs cycle, or other metabolic pathways taking place inside the cell are considered endoenzymes.

Q41. Lack of relaxation between successive stimuli in sustained muscle contraction is known as:

• A. Tetany✓
• B. Arthritis
• C. Spasm
• D. Fatigue

Explanation: Tetany refers to a condition in which the nerves innervating a particular muscle become overstimulated and cause involuntary contractions of muscles called as spasms. Tetany is also referred to as tetanic seizures. B. This is inflammation of joints. C. Spasm are painful contraction and tightening of muscles. D. Fatigue is when muscles lose ability to contract. This conditon is temporary and lasts for a short time . FTB page# 53

Q42. Which of the following most appropriately describes haemophilia?

• A. Chromosomal disorder
• B. Dominant gene disorder
• C. Recessive gene disorder
• D. X-­linked recessive gene disorder✓

Explanation: Haemophilia is a sex-­linked disease. It occurs due to the presence of a recessive sex linked gene h, which is carried by the X-chromosome.

Q43. Chlorophyll molecule resemble the haem group of hemoglobin, the main difference between these two molecule is that chlorophyll has _ ion.

• A. Fe2+
• B. Mg2+✓
• C. Mn2+
• D. Ca2+

Explanation: Chlorophyll’s porphyrin ring is built around Mg2+ whereas the porphyrin ring of hemoglobin is built around iron Fe2+.

Q44. Which of the following is not the type of cells of gastric gland?

• A. Zymogenic
• B. Parietal
• C. Sinusoidal✓
• D. Mucous neck

Explanation: The gastric gland contains four types of cells: parietal cells, chief cells, mucous neck cells, and enteroendocrine cells. Sinusoidal cells are not a type of cell found in the gastric gland.

Q45. Which of the following animals can survive without drinking water?

• A. Kangaroo rat✓
• B. Pig
• C. Kangaroo
• D. Camel

Explanation: The kangaroo rat is almost perfectly adapted to life in the desert. They can survive without ever drinking any water, getting needed moisture from their seed diet.

Q46. At which site does digestion of starches begin?

• A. 3✓
• B. 7
• C. 8
• D. 12
• E. 13

Explanation: In the mouth, as the chewing begins, saliva is released which has the amylase enzyme. The amylase starts breaking down starch to maltose.

Q47. The rate of photosynthesis and respiration may equal one another at what time?

• A. Dawn
• B. Noon
• C. Dusk
• D. Dawn and dusk✓

Explanation: At dawn and dusk, when light intensity is low, the rate of photosynthesis and respiration may, for a short time, equal one another. Thus the oxygen released from photosynthesis is just the amount required for cellular respiration. Also, the carbon dioxide released by respiration just equals the quantity required by photosynthesizing cells. At this moment there is no net gas exchange between the leaves and the atmosphere. This is termed as compensation point.

Q48. All of the following coelenterates show alternation of generation except?

• A. Hydra✓
• B. Obelia
• C. Aurellia
• D. All of these options are correct

Explanation: Hydra does not show alternation of generation in its life cycle. It also does not have any larval stage during its life cycle.

Q49. The animals of division Radiata are which of the following?

• A. Triploblastic
• B. Diploblastic✓
• C. Radioblast
• D. All of these

Explanation: Characteristics of the radiata is that they are diploblastic. Diploblastic organisms only have two embryonic tissues layers; endoderm and ectoderm.

Q50. A sponge of Antarctica which is more than a meter tall is known as?

• A. Euplectella
• B. Spongilla
• C. Leucosolenia
• D. Scolymastra joubini✓

Explanation: Anoxycalyx ( scolymastra) joubini is the largest and most conspicuous sponge in the Antarctica and although it has been observed as much as 1 m in height.

Q51. Nutrition refers to the processes involved in:

• A. Taking in of food
• B. Utilization of food elements
• C. Growth, repair, and maintenance
• D. All of the above options are correct✓

Explanation: Nutrition is the process of taking in food and converting it into energy and other vital nutrients required for life. Nutrients are the substances which provide energy and biomolecules necessary for carrying out the various body functions. All living organisms need nutrients for proper functioning and growth.

Q52. If lipopolysaccharides did not appear in the wall of bacteria on staining then it will be known as _.

• A. Gram negative
• B. Gram positive✓
• C. Capsule
• D. Both Gram positive & negative

Explanation: The Gram stain procedure distinguishes between Gram positive and Gram negative groups by coloring these cells red or violet. Gram positive bacteria stain violet due to the presence of a thick layer of peptidoglycan in their cell walls, which retains the crystal violet these cells are stained with. Alternatively, Gram negative bacteria stain pink, which is attributed to a thinner peptidoglycan wall, which does not retain the crystal violet during the decoloring process.Gram-positive bacteria do not contain lipopolysaccharides, but carry surface teichoic acids, lipoteichoic acids and peptidoglycan instead.The outer membrane of Gram-negative bacteria contains lipopolysaccharides, proteins, and phospholipids.The bacterial capsule is a large structure of many bacteria. It is a polysaccharide layer that lies outside the cell envelope, and is thus deemed part of the outer envelope of a bacterial cell.

Q53. Which of the following structures provides greater pathogenicity to the bacteria?

• A. Slime✓
• B. Cell Wall
• C. Cell Membrane
• D. Capsule

Explanation: In the question, you need to identify the structure that provides greater pathogenicity to the bacteria. While each component has some effect on bacterial pathogenicity, the slime, which is a soluble sheath of macromolecules, provides greater pathogenicity to bacteria while also protecting them from phagocytosis. Hence, Option A is the correct answer.

Q54. For respiratory metabolism, a bacterial cell membrane contains:

• A. Proteins
• B. Lipids
• C. Enzymes✓
• D. Chemicals

Explanation: Bacterial cells lack membrane-bound organelles such as mitochondria. Therefore, the enzymes needed for respiration are present in invaginations of the cell membrane, called 'Mesosomes'.

Q55. The sex pili is formed in which of the following processes?

• A. Sexual reproduction
• B. Binary fission
• C. Mitosis
• D. Conjugation✓

Explanation: The following diagram shows reproduction by conjugation and it can be seen that the recipient forms a pilus at the end.

Q56. Which of the following is true in case of induced fit model?

• A. The substrate changes its shape slightly.
• B. The enzyme changes its shape slightly.✓
• C. None of them changes shape.
• D. Both changes shape.

Explanation: Correct option B Since according to the induced fit model presented by koshland the binding of substrate or other molecules to enzyme causes changes in enzyme to enhance or inhibit its activity.

Q57. A metal cofactor which is used in synthesis of glycolysis is?

• A. Fe3+
• B. Mn2+
• C. Co2+
• D. Mg2+✓

Explanation: "Mg2+" is an inorganic cofactor used in glycolysis to convert glucose into glucose 6-phosphate.

Q58. The optimum pH for the functioning of enzyme pepsin is:

• A. 2✓
• B. 3
• C. 4
• D. 5

Explanation: The optimum pH for the functioning of the enzyme pepsin is 2. Pepsin is a digestive enzyme produced in the stomach It plays a crucial role in the digestion of proteins.

Q59. Bacteria that live in intestine and produce vitamin K belong to?

• A. Vibrio
• B. Cocci
• C. Spirilla
• D. Bacilli✓

Explanation: Menaquinones are the naturally occurring form of vitamin K identified in bacteria. Bacilli in intestine produce vitamin K.

Q60. Lipid emulsification is done by:

• A. Pancreatic juice
• B. Bile✓
• C. Gastric juice
• D. Intestinal juice

Explanation: Lipid emulsification is done by bile. Bile is a fluid that is produced by the liver and stored in the gallbladder. It is released into the small intestine during digestion, where it helps to break down fats and fat-soluble vitamins.

Q61. The notochord is

• A. Present in adult chordates
• B. Present in all echinoderms
• C. Present in chordates during embryological developents✓
• D. Always a vestigial organ in chordates

Explanation: The notochord is the defining structure of the chordates, and has essential roles in vertebrate development. It serves as a source of midline signals that pattern surrounding tissues and as a major skeletal element of the developing embryo.

Q62. Some enzymes require the presence of a non protein molecule to behave catalytically. An enzyme devoid of this molecule is called a(n):

• A. Holoenzyme
• B. Apoenzyme✓
• C. Coenzyme
• D. Zymoenzyme

Explanation: Enzyme with a non-proteinous part is called Holoenzyme; without that non-proteinous part, it is called Apoenzyme.

Q63. An example of competitive inhibition of an enzyme is the inhibition of;

• A. Succinic dehydrogenase by malonic acid✓
• B. Cytochrome oxidase by cyanide
• C. Hexokinase by glucose
• D. Carbonic anhydrase by carbon dioxide

Explanation: A classic example of competitive inhibition of an enzyme is the inhibition of succinic dehydrogenase by malonic acid. Malonic acid has a structural resemblance to succinate. So, it competes with succinate for the active site on the enzyme succinate dehydrogenase. If the concentration of malonic acid is more, the rate of the enzymatic reaction will be drastically reduced.

Q64. Which type of chlorophyll is found in all types of algae?

• A. Chlorophyll a✓
• B. Chlorophyll b
• C. Chlorophyll c
• D. Chlorophyll d

Explanation: There are four types of chlorophyll: chlorophyll a, found in all higher plants, algae, and cyanobacteria.

Q65. Oxygen, released into the atmosphere, comes from:

• A. CO2
• B. H2O✓
• C. C6H12O6
• D. CO2 and H2O

Explanation: Oxygen released into the atmosphere during photosynthesis comes from the splitting of water molecules. The oxygen-evolving complex in the thylakoid membrane of chloroplasts is responsible for catalyzing the light-dependent reactions of photosynthesis, where water molecules are split into oxygen, protons (H⁺ ions), and electrons.

Q66. First infectious disease against which effective method of prevention developed was a _:

• A. Bacterial disease
• B. Viral disease✓
• C. Protozoan disease
• D. Viroid disease

Explanation: a. Bacterial disease: Bacterial diseases were among the first for which effective prevention methods were developed. Vaccination, such as the smallpox vaccine developed by Edward Jenner, is a notable example. b. Viral disease: This option is correct. The smallpox vaccine, developed in the late 18th century by Edward Jenner, is a landmark achievement in the prevention of viral diseases. It played a crucial role in the eventual global eradication of smallpox. c. Protozoan disease: Protozoan diseases are caused by single-celled organisms (protozoa). Prevention methods for these diseases often involve medications (antiprotozoal drugs) rather than vaccines. Malaria, caused by the Plasmodium protozoan, is an example of a protozoan disease with preventive measures like antimalarial drugs and bed nets. d. Viroid disease: Viroids are infectious agents consisting of small, circular RNA molecules. They cause diseases in plants. Preventive methods for viroid diseases typically involve plant hygiene and control measures, as there are no widely recognized vaccines for viroids. Correct Answer: b. Viral disease Explanation: The smallpox vaccine is a historic example of the first effective prevention method developed against a viral disease, marking a significant milestone in the history of infectious disease control. Summary: The correct answer is b. Viral disease. The smallpox vaccine, developed for the prevention of smallpox caused by the variola virus, is a groundbreaking achievement in the history of infectious disease prevention. While bacterial diseases also saw early success with vaccination, the smallpox vaccine stood out as a pivotal moment in addressing viral infections and contributed to the eventual global eradication of smallpox.

Q67. Vaccines for all of these have been developed EXCEPT:

• A. Polio
• B. Mumps
• C. Measles
• D. Cancer✓

Explanation: Vaccine is a preparation that is used to stimulate the body's immune response against diseases

Q68. The Porifera are pore - bearing animals, commonly called:

• A. Corals
• B. Sponges✓
• C. Hydras
• D. Anemones

Explanation: Factual recall. Sponges have numerous pores called ostia and hence are known as porifera. Option A is scientifically referred to as the class anthozoa within the phylum cnidaria. Option C is scientifically referred to as the phylum Coelenterata. Option D is scientifically referred to be within the phylum Cnidaria.

Q69. Which statement correctly describes the alimentary canal of hydra?

• A. The alimentary canal is formed from the endodermal cells
• B. The alimentary canal has a single opening
• C. The alimentary canal is saclike
• D. All of the above✓

Explanation: In simple invertebrates, such as hydras and flatworms, the digestive system is a sac with a single opening. A hydra has a central cavity that holds prey; the cavity is lined by a layer os specializd cells that secrete digestive enzymes to break down the prey's tissues.

Q70. The number of spinal nerves along the spinal cord is:

• A. 16 pairs
• B. 20 pairs
• C. 31 pairs✓
• D. 33 pairs

Explanation: There are 31 pairs of spinal nerves in the human body. These nerves emerge from the spinal cord and pass through openings between adjacent vertebrae, distributing to various regions of the body.

Q71. The brain is protected by:

• A. Sacrum
• B. Cranium✓
• C. Humerus
• D. Scapula

Explanation: The brain is produced by the "b) Cranium," which forms the protective bony enclosure for this vital organ.The cranium, also known as the skull, is the bony structure that forms the protective enclosure for the brain. It is a complex structure made up of several bones that fuse together during development to provide a solid and robust casing for the brain. The cranium not only safeguards the brain from external injuries but also provides support and structure to the head.The brain is a vital organ of the central nervous system, responsible for controlling various bodily functions, cognitive processes, emotions, and voluntary and involuntary actions. It is encased within the cranium to shield it from mechanical damage and to maintain a stable and protective environment.

Q72. The shape of gray matter is:

• A. Spherical
• B. Butterfly✓
• C. Mosquito
• D. Rectangular

Explanation: Option A: This is not the correct shape.Option B: Shape of gray matter in the spinal cord is H or butterfly in other words thus this option is correct.Option C: Mosquito is not a shape it is an insect therefore this answer is incorrect.Option D: This is not the correct shape.

Q73. Hypothalamus initiates the release of hormones, by their releasing factors, while _ is directly released by it.

• A. TSH
• B. ACTH
• C. FSH
• D. Dopamine✓

Explanation: The hormones produced in the hypothalamus are corticotropin-releasing hormone, dopamine, oxytocin, growth hormone-releasing hormone, somatostatin, gonadotropin-releasing hormone and thyrotropin-releasing hormone.

Q74. Venous blood en route from the kidneys to the heart must pass through the:

• A. Iliac vein
• B. Inferior vena cava✓
• C. Liver
• D. Hepatic vein
• E. Pulmonary vein

Explanation: The kidneys receive unfiltered blood directly from the heart through the abdominal aorta which then branches to the left and right renal arteries. Filtered blood then returns by the left and right renal veins to the inferior vena cava and then the heart.

Q75. Premature birth or miscarriage is usually caused by the disturbance in secretion of which of the following hormone?

• A. Estrogen
• B. Progesterone✓
• C. Lactogen
• D. Luteinizing Hormone (LH)

Explanation: Progesterone is one of the sex hormones closely associated with pregnancy and the menstrual cycle. It can also play a role in recurrent miscarriages or premature birth.

Q76. Suggest which among the following is not a function attributed to endoplasmic reticulum?

• A. Detoxification of poisons and drugs
• B. Digestion/egestion of foreign materials outside the cell✓
• C. Manufacture of fat and lipid molecules
• D. Biogenesis of membrane proteins

Explanation: The endoplasmic reticulum is involved in the detoxification of the poisons and the drugs. This is the main function of the endoplasmic reticulum in the liver. The manufacturing of the lipids and fat molecules take place in the smooth ER. The membrane proteins are synthesised on the ribosomes which are present on the surface of the ER. The digestion and egestion of the foreign materials which enter the cells take place in the lysosomes. Thus, the correct answer is option B.

Q77. Which property of water helps to maintain the integrity of lipid-containing membranes?

• A. Specific Heat Capacity
• B. Hydrogen Bonding
• C. Cohesion and Adhesion
• D. Hydrophobic exclusion✓

Explanation: If you place a few drops of oil on the surface of a water solution, the oil drops will tend to coalesce (to unite into one whole) into a single drop. Biologically, hydrophobic exclusion plays a key role in maintaining the integrity of lipid bilayer membranes due to the hydrophobic tails of the phospholipid molecules. Tails of two layers of phospholipids interact to form a hydrophobic internal center of cell membranes while the phospholipid heads interact with the hydrophilic water medium externally. This is shown below.

Q78. Which of the following is correct for the given structure?

• A. These are small structures which work like oars
• B. It is covered with plasma membrane
• C. It's core is called axoneme
• D. All of the above✓

Explanation: Cilia and flagella are hair-like outgrowths of the cell membrane. Cilia are small structures working like oars, causing the movement of either the cell or the surrounding fluid. Flagella, in comparison, is longer and is responsible for cell movement. Both cilium and flagellum are covered with plasma membrane. Their core, called axoneme, possesses a number of microtubules running parallel to the long axis. So, the correct answer is 'All of the above'.

Q79. HIV is also known as:

• A. AIDS✓
• B. HAV
• C. HTLV
• D. HBV

Explanation: AIDS is merely an advanced form of HIV.

Q80. Tay Sach's disease is caused by absence of enzyme required to breakdown _.

• A. Lipids✓
• B. Glycogen
• C. Glucose
• D. Proteins

Explanation: Tay-Sachs disease is a inherited disorder that progressively destroys nerve cells (neurons) in the brain and spinal cord. It is caused due to the mutation in the gene which is responsible for producing enzyme involved break down of fatty substance.

Q81. A combination of alpha interferon and ribavirin is used for the treatment of hepatitis:

• A. Hepatitis B
• B. Hepatitis A
• C. Hepatitis D
• D. Hepatitis C✓

Explanation: The combination of alpha interferon and ribavirin has been used in the treatment of hepatitis, particularly in the context of hepatitis C. Both alpha interferon and ribavirin have antiviral properties, and their combination was historically a standard treatment for chronic hepatitis C infection. Here's a brief overview of each component: Alpha Interferon: interferons are proteins that the body naturally produces in response to viral infections. They have antiviral properties and can modulate the immune response. Alpha interferon is a specific type of interferon that has been used as part of antiviral therapy. It was administered as an injection. Ribavirin: Ribavirin is an antiviral medication that inhibits the replication of viruses. It is a nucleoside analog and can interfere with the synthesis of viral genetic material. Ribavirin was often administered orally as part of the treatment regimen.

Q82. “Zymase”- a group of 14 enzymes, used in the fermentation of starch, is present in:

• A. Bacteria
• B. Yeast✓
• C. Fungi
• D. Algae
• E. Virus

Explanation: Zymase is an enzyme complex that catalyzes the fermentation of sugar into ethanol and carbon dioxide. It occurs naturally in yeasts. Zymase activity varies among yeast strains. Zymase is also the brand name of the drug pancrelipase.

Q83. Match the parts of the human brain listed under Column I with the functions given under Column II. Choose the answer which gives the correct combination of alphabets of the two columns.

• A. A=r, B=q, C=p, D=s
• B. A=r, B s, C=q, D=t,
• C. A=t, B p, C=q, D=r✓
• D. A=t, B=q, C=p, D=s

Explanation: Cerebral Hemisphere deals with intelligence and memory. Thalamus deals with relaying impulses. Cerebellum deals with posture and balance. Medulla oblongata deals with the control of sleep and waking.

Q84. Which of the following neurotransmitters function, both as neurotransmitter and hormones, decreasing our perception of pain?

• A. Epinephrine
• B. Serotonin
• C. Dopamine
• D. Endorphins✓

Explanation: Neurotransmitters are chemical messengers that transmit a message from a nerve cell across the synapse to a target cell. Hormones are chemical messengers that are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions. All the options are both, a hormone as well neurotransmitters. Epinephrine, commonly referred to as Adrenaline, relaxes the airway muscles, making it easier for the person to breathe. At the same time, it constricts blood vessels, helping to improve blood pressure. It also increases the heart rate. However, it does not decrease the response to pain. Hence Option A is rejected. Serotonin, on the other hand, is used by the body to send messages between nerve cells. It appears to play a role in mood, emotions, appetite, and digestion. As the precursor for melatonin, it helps regulate sleep-wake cycles and the body clock. Since it is not used to decrease pain response, Option B is rejected. Dopamine is a neurotransmitter that plays a role in how we feel pleasure. It's a big part of our unique human ability to think and plan. However, it plays no role in the pain response. Hence Option C is rejected. Endorphins are substances produced by the nervous system to cope with pain or stress. They are often called “feel-good” chemicals because they can act as pain relievers and happiness boosters. Hence, Option D is correct.

Q85. In a typical compound microscope the resolution is 2 μm. Which is about _ that of naked eye.

• A. 100 x
• B. 300 x
• C. 400 x
• D. 500 x✓

Explanation: A human eye cannot distinguish objects smaller than 1000 μm (1 mm). In other words, the resolution of a human eye is 1000 μm, while a light microscope can typically magnify images up to 500× to resolve details down to 2 μm.

Q86. Which one of the following combinations is NOT the part of an animal cell?

• A. Central Vacuole, Cell Membrane, Ribosomes
• B. Chloroplast, Ribosome , Mitochondria
• C. Cell wall, Chloroplast, Central vacuole✓
• D. Ribosome, Mitochondria, Cell wall

Explanation: Animal cells do not have a Cell wall and Chloroplasts. They have temporary small vacuoles; unlike plant cells which have large, permanent, central vacuoles. In the other options, at least one feature is present in the animal cells instead of all the three features pertaining to animal cells. The idea is to choose the better answer. The diagram presented below shows the major organelles in an animal cell;Flexibility and Mobility: Animal cells are often required to move and change shape, which is facilitated by their flexible cell membrane. The absence of a rigid cell wall allows animal cells to have more flexibility and mobility compared to cells with a cell wall. This flexibility is essential for various cellular processes, including cell migration, muscle contraction, and the ability to form complex tissues and organs. Intercellular Communication: Animal cells rely on direct cell-to-cell communication through specialized structures like gap junctions and tight junctions. These junctions facilitate the exchange of signals, ions, and molecules between neighboring cells, allowing for coordinated responses and tissue organization. A cell wall would hinder the direct interaction between animal cells and impede the efficient communication required for their complex physiological processes. Structural Support: In the absence of a cell wall, animal cells utilize the cytoskeleton, a network of protein filaments, to maintain their structural integrity and provide support. The cytoskeleton allows animal cells to maintain their shape, organize their internal components, and carry out cellular functions. This dynamic framework provides mechanical strength while allowing flexibility and shape changes. Adaptation to Environment: Animals have evolved to inhabit diverse environments and face varying physical conditions. The absence of a rigid cell wall enables animal cells to adapt to different osmotic pressures, temperature changes, and other environmental factors. Animal cells can regulate their volume and shape in response to external stimuli, allowing them to survive and function effectively in their respective environments. It's important to note that while animal cells lack a cell wall, they still possess a cell membrane (plasma membrane) that separates the cell's internal environment from the external environment. The cell membrane is a selectively permeable barrier that controls the passage of substances in and out of the cell.

Q87. 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: Increasing the pressure favors the side where the volume of gases is less. Since NH3 lies at the product side where total moles (volumes) of gases is 2 as compared to volume on the left side (reactant side) which 4. Increasing the pressure favors the NH3 production. Catalyst does not favor any side it increases the forward as well as the backward rate of reaction. Hence the answer is D.

Q88. 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.

Q89. 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. Therefore, according to the law of mass action, “the rate of the chemical reaction is directly proportional to the product of the activities or concentrations of the reactants”. So, from this statement, we can conclude that the rate of reaction depends upon the concentrations of the reactants which increase the speed of reaction with the increase in the chemical reaction. Hence the correct option is B.

Q90. When 18 x 10-3 moles/dm3 of acetic acid react with 22 x 10-3 moles/dm3 of ethyl alcohol to form 40 x 10-3 moles/dm3 of ethyl acetate and 40 x 10-3 moles/dm-3 of water. Find the value of equilibrium constant (kc):

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

Explanation: Kc=[40x10-3][40x10-3]/[18x10-3][22x10-3]Kc=4.04

Q91. Many elements have fractional atomic masses. This is because:

• A. Mass of atom is itself reactional
• B. Atomic masses are average masses of isobars
• C. Atomic masses are average masses of isotopes
• D. Atomic masses are average masses of isotopes proportional to their abundance✓

Explanation: Atomic masses are typically reported as weighted averages that take into account the abundance of each isotope of an element. Most elements exist as a mixture of isotopes, and these isotopes have different masses. The atomic mass of an element listed on the periodic table is a weighted average of the masses of its naturally occurring isotopes. The weighting is based on the abundance of each isotope in nature. Since isotopes have different masses, the atomic mass is not a whole number, and it may appear as a fractional value.

Q92. The best standard for the calculation of relative atomic masses is:

• A. Hydrogen - 1.008
• B. Carbon - 12✓
• C. Carbon - 13
• D. Oxygen - 16

Explanation: Atomic mass is defined as the mass of an atom of an element compared with the mass of an atom of carbon 12 (the stable light isotope of carbon). Atomic mass is a ratio and therefore has no units. It may be given any unit of measure, but generally, atomic masses are expressed in atomic mass units (a.m.u). One atomic mass unit equals exactly 1/12th the mass of a carbon 12 atom.Therefore, the most common standard for measuring an atom is the mass of carbon-12 and hence, option B is the correct answer.

Q93. At 1489 mm of Hg, water will boil at:

• A. 120 C✓
• B. 110 C
• C. 100 C
• D. 90 C

Explanation: Although you are not expected to know the calculation of boiling point at various pressures, you must understand that at pressures higher than atmospheric pressure, the boiling point must also be higher than that at atmospheric pressure. This is because the boiling point is defined as the temperature at which the vapour pressure equals the external pressure. So, the higher the pressure, the higher the required temperature to evaporate enough liquid to equal the external pressure. Since 1489 mm of Hg>760 mm of Hg(atmospheric pressure) , the boiling point must also be greater than 100. The best option in this case is, therefore, option A. If you have read the book thoroughly, this may just be a factual recall for you:

Q94. Which one of the following has the highest lattice energy?

• A. NaCl
• B. KCl
• C. KBr
• D. LiCl✓

Explanation: The lattice enthalpy is the enthalpy change involved in the formation of an ionic compound from gaseous ions (an exothermic process). The Lattice energy is directly proportional to the charges of the ions but inversely proportional to the radii of the ions or more generally the distance between ions. Lattice Energy α (charge of ion/radius of the ion). As we go down in a group (Group 1 and 7 in this case), ionic radius increases, and as the net charge is constant (+1 and -1 respectively), the lattice energy of their compounds decreases. Order of cation radius: K+> Na+> Li+ Order of anion radius: Br-> Cl- Hence, the compound LiCl will have the greatest Lattice energy as both the ions have the least radius. Note: Across a period from left to right as the charge on ion increases, lattice energy increases.

Q95. Industrially water gas is converted into methanol by using catalyst:

• A. CuO + ZnO
• B. CuO + Cr2O3
• C. Al2O3 + ZnO
• D. ZnO + Cr2O3✓

Explanation: Industrial preparation of methanol takes place by first purifying a mixture of CO and H2 gas (collectively called water gas), then compressing them at 200 atm and then passing them over a heated catalyst at 200℃. The catalyst used in the reaction chamber is a mixture of ZnO and CrO3. Methanol vapours are formed which are condensed to form methanol. Option D is correct.(Source: PCTB book 2, page 214)

Q96. The nature of Lysine is:

• A. Acidic
• B. Basic✓
• C. Neutral
• D. Weakly acidic

Explanation: The chemical nature of an amino acid depends on its variable ‘R’ group. The R group of lysine contains the NH2 group which is basic as it can accept a proton to form NH3+.Therefore, lysine is considered to be a basic amino acid and hence option B is correct.

Q97. Reaction of CH3CH2MgBr with ethylene epoxide gives:

• A. Ethanal
• B. 1 - butanol✓
• C. 2 - butanol
• D. Butane

Explanation: The reaction of CH3CH2MgBr (ethylmagnesium bromide) with ethylene oxide (ethylene epoxide) typically results in the formation of 1,2-propanediol. This reaction is an example of a nucleophilic substitution reaction in which the nucleophilic carbon of the organometallic reagent attacks the electrophilic carbon of the epoxide, leading to the formation of an alcohol.The reaction can be represented by the following equation:CH3CH2MgBr + C2H4O-> CH3CH2CH2OHIn this reaction, the ethylmagnesium bromide acts as a nucleophile, attacking the epoxide ring and displacing the bromide ion. The resulting intermediate is an alkoxide ion, which quickly protonates to form the corresponding alcohol, 1,2-propanediol.It's important to note that the reaction conditions, such as temperature, solvent, and presence of any catalysts, can influence the outcome of the reaction. However, under typical conditions, the reaction described above is the most common result.Ethylene epoxide reacts with Grignard’s Reagent to produce an additive product, which upon hydrolysis yields a primary alcohol. The type of primary alcohol depends upon the number of C atoms in the grignard reagent’s ‘R’ group (RMgX).Since we have two C in Grignard’s Reagent and two in ethylene epoxide, the total number of carbon atoms in primary alcohol will be four, so the name of the alcohol formed is 1-butanol.

Q98. Different kinds of atoms of the same element are called isotope having different _but same _ properties.

• A. Physical, atomic
• B. Physical, chemical✓
• C. Chemical, physical
• D. Chemical, atomic

Explanation: Isotopes of an element have the same atomic number and therefore 'similar chemical properties'. Their physical properties may be 'different'.

Q99. The unit used to express the relative atomic mass is called

• A. Gram unit
• B. Avogadro's number
• C. Atomic mass
• D. Atomic mass unit✓

Explanation: One atomic mass unit (1u) is a mass unit equal to exactly one-twelfth (1/12th) the mass of one atom of carbon-12 isotope, which is the scale used to compare atomic masses. So, the unit used to express relative atomic mass is amu. Thus, option D is correct.

Q100. 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, 48 Manganese has four stable isotopes: 52, 53, 54, 55 Tin has ten isotopes: 112, 114, 115, 116, 117, 118, 119, 120, 122, 124 Carbon has three isotopes: 12, 13, 14. So option C is correct.

Q101. At 0°C what is the physical state of water?

• A. Ice
• B. Liquid
• C. Vapour
• D. Both ice and liquid✓

Explanation: 0 C at 1 atm pressure is the freezing point of pure water where its solid-state and liquid state coesxist in an equilibrium.

Q102. What is the correct demonstration of general gas equation?

• A. PV/RT=n
• B. PV=mRT
• C. V=nRT/P
• D. PV=nRT✓

Explanation: In the general gas equation, volume is directly proportional to number of moles and temperature, and volume is inversely proportional to pressure.If R is universal gas constant, this relation is given by the equation:PV=nRTwhereP= PressureV= volumen= number of molesR= Ideal gas constantT= Temperature

Q103. Which of the following is/are allotrope(s) of Sulphur?

• A. Monoclinic S and Rhombic S✓
• B. Rhombic S
• C. Triclinic S
• D. Monoclinic S

Explanation: Allotropy is the existence of an element in more than one crystalline forms. These forms are known as allotropes. Sulphur exists in both rhombic and monoclinic forms which are in equilibrium with one another at 95.5 C.

Q104. The property of a crystal to grow in its usual shape is called as:

• A. Symmetry
• B. Habit of crystal✓
• C. Isomorphism
• D. Polymorphism

Explanation: The shape in which a crystal usually grows is called the habit of the crystal. If the conditions for crystallization remain the same, then the crystal will grow in the same shape (habit).

Q105. Gases are non-ideal at high pressure due to:

• A. Intermolecular forces
• B. Decrease in volume occupied by gas
• C. All of these✓
• D. Decrease in compressibility of gas

Explanation: Ideal gases are those that have no intermolecular forces, their molecular volume is negligible as compared to the volume of the entire gas and are infinitely compressible.As the pressure on a gas increases, the gas molecules are brought closer together. This decrease in the total volume of the gas brings the molecules so close that intermolecular forces of attraction develop between them. Moreover, the individual volume of a gas molecule is not negligible compared to the now decreased total volume of the gas. Due to the increase in pressure, the gas is already compressed, making further compression more difficult. So, its compressibility decreases.

Q106. HF has a higher boiling point than HCl because of:

• A. Dipole-dipole interactions
• B. Ion-dipole interactions
• C. Hydrogen bonding✓
• D. London-dispersion forces

Explanation: HF has a higher boiling point than HCl because of the hydrogen bonding that exists between HF molecules. HCl has dipole-dipole intermolecular interactions. Out of the two, hydrogen bonding is stronger, hence, the greater boiling point of HF.

Q107. The maximum number of electrons that an orbital can accommodate is/are:

• A. 0
• B. 1
• C. 2✓
• D. 3
• E. 4

Explanation: The maximum number of electrons in a single orbital is two. The maximum number of electrons an orbital can accommodate is 2. As in an orbital two electrons can never have the same values of all 4 quantum no.s according to Pauli’s exclusion principle. So to follow this rule, an orbital can accommodate 2 electrons only.

Q108. In a reaction: A+B < - > 2C When equilibrium was attained, the concentration was [A] = [B] = 4 moles/dm3 [C]= 6 moles/dm3The equilibrium constant Kc of this reaction is:

• A. 1.25
• B. 2.25✓
• C. 3.25
• D. 2.75
• E. 3.75

Explanation: We know Kc is the product of concentration of products raised to the power in a balanced chemical equation divided by the product of concentration of reactants raised to the power in a balanced chemical equation.For given reaction,Kc = [C]² / [A][B]Kc = 6² / 4x4Kc = 36 / 16Kc = 2.25

Q109. When two moles of H2 and one mole of O2 react to form H2O, -484 KJ heat is evolved. What is Δ Hf for one mole of H2O?

• A. -484 KJmol-1
• B. -242 KJmol-1✓
• C. -121 KJmol-1
• D. +242 KJmol-1

Explanation: To determine the enthalpy change of formation (ΔHf) for one mole of H2O, we can use the given information about the heat evolved in the reaction.The balanced equation for the reaction is:2H2(g) + O2(g) → 2H2O(g)According to the given information, when two moles of H2 and one mole of O2 react, 484 kJ of heat is evolved. This heat change represents the enthalpy change of the reaction.Since two moles of H2O are formed in the reaction, we need to find the enthalpy change for one mole of H2O. To do that, we divide the heat evolved by the stoichiometric coefficient of H2O:ΔHf (H2O) = (484 kJ) / 2ΔHf (H2O) = 242 kJTherefore, the enthalpy change of formation for one mole of H2O is 242 kJ.Firstly, since heat is evolved, the formation of water is an exothermic reaction and so the sign of enthalpy change will be negative. Secondly, enthalpy of formation is the change in enthalpy when one mole of a substance is formed from its constituent elements under standard conditions.When 2 moles of H2 and 1 mole of O2 react, 2 moles of H2O will be formed:2H2 + O2 —------------------------> 2H2O ΔH=-484 kJ/mol (given)Now, for the formation of one mole of H2O, we can simply divide the entire equation by 2:H2 + ½ O2 —-----------------------> H20 ΔH= -242 kJ/molSo, the enthalpy change of formation is –242 kJ/mol, which corresponds to option B, hence that is the correct answer.

Q110. Which of the following metals does NOT liberate hydrogen in reaction with acids?

• A. Mg
• B. Pt✓
• C. Zn
• D. Ca

Explanation: Metals exhibit displacement reactions on the basis of their reactivity. All the metals Mg, Zn and Ca in the options A, C and D respectively are above Hydrogen in the reactivity series and therefore will displace it from an acid. Platinum, however, is below hydrogen and so will not displace it and will not liberate H2 gas on reaction with an acid. Therefore option C is the correct answer. The reactivity series of metals is given below:

Q111. The rate of a gaseous reaction Is given by K [A] [B]. If the volume of the vessel containing these gases is reduced to 1/4th of the initial volume, the rate of reaction relative to the original rate would be:

• A. 16/1✓
• B. 1/16
• C. 4/1
• D. 1/8
• E. 8/1

Explanation: If the volume of the vessel is reduced by 1/4th that means according to formula C=n/V concentration of each gas in the flask increases by a factor of 4 times. Since concentrations of two gases are increased by this factor that increases the overall rate by 4x4=16.

Q112. "In an atom no two electrons can have the same set of four Quantum numbers" is stated by:

• A. Heisenberg’s uncertainty principle
• B. Aufbau Principle
• C. Pauli's Exclusion principle✓
• D. Hund's Rule
• E. (n+1) Rule

Explanation: The set of numbers used to describe the position and energy of the electron in an atom are called quantum numbers. There are four quantum numbers namely, principal, azimuthal, magnetic and spin quantum numbers. Pauli's exclusion principle states that in an atom no two electrons can have the same set of four quantum numbers. Let us take example of electrons in Helium, both have all quantum numbers same except spin quantum number, one is clockwise and other is anti-clockwise.

Q113. The unit of rate of reaction is:

• A. Mole (dm3) sec
• B. Mole (dm3) sec-1
• C. Mole(dm-3) sec -1✓
• D. Mole(dm3)sec-2
• E. Mole (dm3)-1 sec -2

Explanation: Reaction rates are usually expressed as the concentration of reactant consumed or the concentration of product formed per unit time. The units are thus moles per decimeter cube per unit time [Mole (dm-3)'sec -1 ].

Q114. The chemical reaction in which reactions require high amount of activation energy are generally:

• A. Slow✓
• B. First fast then slow
• C. First slow then fast
• D. Spontaneous

Explanation: The activation energy of a chemical reaction is closely related to its rate. Specifically, the higher the activation energy, the slower the chemical reaction will be. This is because molecules can only complete the reaction once they have reached the top of the activation energy barrier.

Q115. The rate of a chemical reaction is directly proportional to the product of active masses of the reactants, it is referred to as:

• A. Law of conservation of energy
• B. Law of mass action✓
• C. Law of conservation of mass
• D. Active mass law

Explanation: The law of mass action states the rate of chemical reaction is directly proportional to the product of the reactant concentration values. This law gives a formula for the equilibrium constant:Kc={C}^c {D}^d/{A}^a {B}^b

Q116. The charge on one proton is:

• A. 1.602 x 10-31 C
• B. 1.602 x 10-27 C
• C. 1.602 x 10-19 C✓
• D. 1.602 x 10-11 C

Explanation: This is a factual recall question. The charge on a proton is equal to +1e, where e is the elementary charge having a value of 1.602 x 10-19 coulombs. This is the same as the charge on an electron but has a different polarity, i.e. positive instead of negative for electrons.

Q117. The oxidation state of carbon in C2O42- is:

• A. +4
• B. -4
• C. +3✓
• D. +2

Explanation: The oxidation number is the apparent charge on an atom of an element in a molecule or ion. It may be positive, negative, or zero. The rules for calculating oxidation number are as follows: Considering all the rules here, particularly point numbers (iv) and (vi), let us assume that the oxidation number of carbon is x, so the equation that we get is: 2x + 4(-2) = -2 2x - 8 = -2 2x= 6 x= +3 Hence the oxidation number of C in oxalate ions is +3, therefore, the correct answer is option C.

Q118. Hybridization of carbon in -CHO group is:

• A. sp
• B. sp2✓
• C. sp3
• D. dsp

Explanation: In the CHO group, - HC=O, the carbon is double bonded to an oxygen and single bonded to hydrogen and another R group, which may be an alkyl or some other group. It has no lone pairs remaining. In other words, the central atom Carbon is bonded to three other groups only. Therefore the hybridisation that it corresponds to is sp2, as can be confirmed from the table below:

Q119. Dehydration of ethanol at 100 oC in the presence of concentrated H2SO4 gives:

• A. Ethene✓
• B. Ethane
• C. Ethyne
• D. Ether

Explanation: Dehydration reactions involve the removal of a water molecule from a compound. This process is commonly used to prepare alkenes from alcohols. However, dehydration reactions are not suitable for preparing alkanes, ethyne (acetylene). Overall, the suitability of dehydration reactions depends on the presence of appropriate functional groups within a molecule. Alkenes, which contain a carbon-carbon double bond, are suitable for dehydration as the removal of a water molecule can occur from the hydroxyl group (-OH) of an alcohol. Alkanes, ethyne, and ethers lack the necessary functional groups and do not undergo dehydration reactions under normal conditions.

Q120. Which of the following is the worst conductor of electricity?

• A. Hg
• B. Distilled water✓
• C. NaCl(l)
• D. Dilute sugar solution

Explanation: In order to conduct electricity, a substance must possess charged particles, either ions or electrons. Distilled water has neither of those as it does not dissociate into H+ or OH- ions unless it is dissolved with some other polar substance. Hence it does not conduct electricity and therefore option B is the correct answer.

Q121. 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).

Q122. Catenation is a process in which carbon shows the properties of:

• A. Making single bond
• B. Hybridization
• C. Making chains or rings of carbon atoms✓
• D. Isomerism
• E. Breaking of bonds

Explanation: Catenation is the process by which an atom is able to form a bond with another atom of its kind. Carbon possesses this ability hence is able to form ringed structures.

Q123. Primary Alcohol is produced by reactions of Grignard's reagent with _ followed by hydrolysis in an acidic medium.

• A. Carbon dioxide
• B. Formaldehyde✓
• C. Acetaldehyde
• D. Ketone
• E. Methyl chloride

Explanation: The Grignard Reaction is the addition of an organomagnesium halide (Grignard reagent) to a ketone or aldehyde, to form tertiary or secondary alcohol, respectively. The reaction with formaldehyde leads to primary alcohol.

Q124. Which of the following is TRUE regarding Methyl Alcohol?

• A. It is a colorless, volatile, thin liquid with specific gravity 0.796 at 15°C.✓
• B. It is used for low-temperature thermometers and as a fuel substitute.
• C. It is extensively used in the formation of different beverages.
• D. It is used as a base for perfumes
• E. It is used as an antiseptic and disinfectant

Explanation: Properties of Methyl Alcohol include: -Colourless -Volatile -Thin liquid with a specific gravity of 0.796 at 15°C. Methyl alcohol is not an effective sanitizer. Since it is toxic and can readily be absorbed under the skin it is never used as a perfume. For the same reason not used to make beverages. It is not used in thermometers. Options B and C are the characteristics of Ethanol. Option D represents esters. Option E represents Phenol.

Q125. The diagram below represents the process of:

• A. Hydrolysis
• B. Condensation✓
• C. Neutralization
• D. Metabolism

Explanation: When two monomers join together to form a single product, with the removal of H2O, the process is called the condensation process. Hence, option B is correct.

Q126. Valence electronic configuration Cu+2 is (29Cu)

• A. 5d6
• B. 3d9✓
• C. 3d8
• D. 3d7

Explanation: The valence electronic configuration of Cu+2 is derived from the neutral atom of copper (Cu), which has an atomic number of 29. The electronic configuration of neutral copper (Cu) is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d¹⁰. When copper loses two electrons to form the Cu+2 ion, the two outermost electrons from the 4s orbital are removed. Therefore, the valence electronic configuration of Cu+2 is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁹. Cu is an element of d-block. Its electronic configuration is anomalous owing to the stability associated with half filled and as in the case of Cu, completely filled d-subshell. One electron from the 4s subshell jumps to 3d subshell, thereby making the electronic configuration: 1s2, 2s2, 2p6, 3s2, 3p6, 4s1, 3d10 Now, for the formation of Cu2+ ion, the Cu atom must lose 2 electrons from the highest energy level. The important thing here is that the 4s orbital of an atom usually fills before electrons go into its 3d orbitals because the 4s orbital is slightly lower in energy than the empty 3d orbitals (n+l rule). However, once electrons are in the 3d orbital, the 4s is no longer lower in energy, it becomes higher in energy than 3d so when ionisation occurs electrons are lost from the 4s orbital before they're lost from the 3d orbitals. Hence, the first electron is lost from 4s and the one after that, from 3d. So the new electronic configuration from Cu2+ is: 1s2, 2s2, 2p6, 3s2, 3p6, 4s0, 3d9 Therefore, option B is the correct answer.

Q127. The total number of transition elements is:

• A. 58✓
• B. 48
• C. 30
• D. 25

Explanation: This is a factual recall question. There are 58 transition metals in the periodic table of elements, of which 30 are outer transition elements (d-block) and 28 are inner transition elements (f-block). Therefore option A is correct. (Source: FTBB book 2 page 64)

Q128. Which of the following does not act as ligand in the formation of complexes?

• A. CH3NH2
• B. OH-
• C. Cl-
• D. NH4+✓

Explanation: Ligand is a species that donates a lone pair of electrons by forming a dative coordinate bond with a central metal atom/ion. NH4+ has no lone pair of electrons because 4 of the valence electrons of nitrogen are involved in forming covalent bonds with hydrogen and 1 electron has been lost by it, being an ion of +1 charge. Therefore it cannot form a dative bond and hence cannot act as a ligand. The correct answer is therefore option D.

Q129. The ratio of σ to π bonds in benzene is:

• A. 4:1✓
• B. 1:4
• C. 1:3
• D. 3:1

Explanation: The structure of benzene reveals that it has 3 C-C double bonds, hence it has three π bonds for each double bond that it makes. It also possesses 6 C-C single bonds and 6 C-H single bonds, making a total of 12 σ bonds.Ratio of σ:π = 12:3 = 4:1Therefore option A is the correct answer. OIP.kJ8bRcHGdSByWKiFdeWugwHaHa (474×474) (bing.com)

Q130. Which of the following alcohol does not get oxidized when it reacts with K₂Cr₂O₇/H₂SO₄?

• A. CH₃C(CH₃)₂OH✓
• B. CH₃CH(CH₃)OH
• C. CH₃OH
• D. C₂H₅OH

Explanation: Option A is a tertiary alcohol which cannot be oxidized with K2Cr2O7 as the central carbon atom has no free hydrogens. Option B is a secondary alcohol which oxidizes to a ketone. Option C is methanol which oxidizes to carbondioxide. Option D is ethanol which oxidizes to ethanal first then ethanoic acid.

Q131. The classification of monohydric alcohols is due to

• A. Hydrogen atom
• B. Carbon atom
• C. Hydroxyl group✓
• D. Carbonyl group

Explanation: The explanation for this question will be added soon!

Q132. Acyclic hydrocarbons are also called as _.

• A. Closed chain hydrocarbons
• B. Open chain hydrocarbons✓
• C. Ring compounds
• D. Alicyclic compounds

Explanation: Acyclic are open-chain hydrocarbons while cyclic compounds are closed-chained compounds.

Q133. How many molecules of H2 are added in acetylene to form ethane?

• A. 1
• B. 3
• C. 4
• D. 2✓

Explanation: Acetylene, C2H2, can be converted to ethane, C2H6, by a process known as hydrogenation. One molecule of H2 when added to acetylene forms ethene. The addition of another molecule of H2 results in the formation of ethane. A total of 2 molecules of H2 are hence required Option A,B and C are incorrect

Q134. 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 2A[Be, Mg, Ca, Sr, Ba].

Q135. 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.

Q136. 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.

Q137. H2S is an example of _ hydride.

• A. Ionic
• B. Covalent✓
• C. Complex
• D. Metallic
• E. Border - line hydride

Explanation: Covalent hydrides are formed when hydrogen reacts with other similar electronegative elements like Si, C,etc. H2S is a covalent hydride because the two elements used in the formation of this hydride are non-metals.

Q138. Lithium and beryllium are unique in such a way that they have higher charge densities which produce strong polarizing effects due to:

• A. Non-metal
• B. Solubility
• C. Small Size✓
• D. Large size

Explanation: smaller size is the main cause of high charge density and increasing polarizing effect. The polarizing power of a cation is inversely proportional to its size. Smaller is the size of the cation and higher will be its charge density, which means greater concentration of charge on a smaller area. The more will be the charge density, higher will be its polarising power.

Q139. If the difference between electronegativity values between two atoms is less than 1.7 , the bond is necessarily:

• A. Ionic
• B. Covalent✓
• C. Electrovalent
• D. Polar
• E. Non - polar

Explanation: If the electronegative difference is >1.7 then its nature is ionic and <1.7 then its nature is covalent and if its equal to 1.7 then nature of bond will be 50% ionic and 50% covalent.

Q140. Order of the reactivity of halogens during halogenation of alkanes is:

• A. Cl2 > I2 > Br2
• B. Br2 > I2 > Cl2
• C. I2 > Cl2 > Br2
• D. Cl2 > Br2 > I2✓

Explanation: The chlorine radical is the most reactive of the among the given halogen molecules and it reacts easily with alkanes. In contrast, the iodine radical is the least reactive of the halogen radicals. In fact, it is so unreactive that it is unable to abstract a hydrogen atom from an alkane.So, (D) option is correct.

Q141. If the temperature is increased from 200K to 800K, then what would be the change in pressure at constant volume?

• A. Increases by factor 4✓
• B. Decreases by factor 4
• C. Increases by factor 2
• D. Decreases by factor 2

Explanation: PV=NR DELT V=constant ;R=constant;N=constant so P is directly proportional toT as the temperature increases 4 times as it increases from 200K to 800K so the pressure will also increase 4 times.Just be careful that the units (especially temperature) are absolute.

Q142. Third law of Newton is also called:

• A. Law of Inertia
• B. Equilibrium
• C. Law of action and reaction✓
• D. None

Explanation: Newton's third law states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction. The third law is also known as the law of action and reaction.

Q143. A body starts sliding on a rough horizontal surface with a speed of 10 m/s. If the coefficient of friction is 0.2, find the distance traveled by the body before coming to rest. (g = 10m/s)

• A. 15 m
• B. 25 m✓
• C. 35 m
• D. 40 m
• E. 55 m

Explanation: Given that: v = 10 and u = 0.2 and g = 10 Solution = Using F = μN then, = μmg (here N = mg) So from above (ma = μmg); we got a = μg Now a = 0.2×10 = 2 m/s2Now using equation of motion V2=u2+2as 0 = 10×10 +2×2×s In solving it, we got s = 100/4 = 25 m Hence we get the correct answer.

Q144. Assume that you have two balls of Identical volume, one weighing 2 Newtons and the other 10 Newtons. Both are falling freely after being released from the same point simultaneously. Which of the following will then be true: I. The 10 N ball falling freely from rest will be accelerated at a greater rate than the 2 N ball II. At the end of the 4s of freefall, the 10 N ball will have 5 times the momentum of the 2 N ball III. At the end of the 4s of free fall, the 10 N ball will have the same kinetic energy as the 2 N ball IV. The 10 N ball possesses greater inertia than the 2 N ball

• A. I, Il and Ill only
• B. I and II only
• C. II and IV only✓
• D. IV only
• E. None of these

Explanation: Acceleration of free fall acts equally on all masses, this is why both objects despite having different masses have the same speed at any point in time. Statement II is correct because two objects have the same velocity but one having 5 times more mass than the other will have 5 times more momentum than the other object. Statement IV is also correct because inertia depends upon mass since a 10N ball has a higher mass it will have greater inertia. Statement III is wrong because objects have different masses so their kinetic energy can not be the same. Statement I is wrong because objects accelerate irrespective of their masses as mentioned before.

Q145. The quantity of heat required to raise the temperature of one mole of a substance through 1 K is called:

• A. Carnot engine
• B. Molar specific heat✓
• C. Kinetic specific heat
• D. General gas law
• E. Boyle's law

Explanation: Specific heat is the amount of heat needed to raise the temperature of one kilogram of mass by 1 degree. The molar heat capacity is the heat capacity per unit amount (SI unit: mole) of a pure substance, and the specific heat capacity often called simply specific heat, is the heat capacity per unit mass of material. Option B is correct.

Q146. Identify the example/s of Static Equilibrium: I. A book lying on a horizontal tableII. A buildingIII. A bridge

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

Explanation: Static equilibrium refers to any system where the sum of the forces, and torque, on every particle of the system happens to be zero. All of the options mentioned above have net torque of zero hence all are under static equilibrium.

Q147. A student is performing a lab experiment on simple harmonic motion. He has two different springs (with force constants k1 and k2) and two different blocks (of masses m1 and m2). If k1 =2k2, and m1 = 2m2, which of the following combinations would give the student the spring-block simple harmonic oscillator with the shortest period?

• A. The spring with force constant k1 and the block of mass m1
• B. The spring with force constant k1 and the block of mass m2✓
• C. The spring with force constant k2 and the block of mass m1
• D. The spring with force constant k2 and the block of mass m2
• E. All the combinations above would give the same period

Explanation: The period of the spring-block simple harmonic oscillator is given by the equation T =2π√m/k so, to make T as small as possible, we want m to be as small as possible and k to be as large as possible. Since m2 is the smaller mass and k1 is the larger spring constant, this combination will give the oscillator the shortest period.

Q148. Some water at 0°C is placed in a large insulated enclosure (vessel). The water vapour formed is pumped out continuously. What fraction of the water will ultimately freeze, if the latent heat vaporization is seven times the latent heat of fusion?

• A. 7/8✓
• B. 8/7
• C. 3/8
• D. 5/8

Explanation: solution:

Q149. Law of Conservation of Momentum states that total linear momentum of system remains constant if:

• A. Balanced external forces are applied to a system.
• B. No external force is applied to a system.✓
• C. Only linear force is applied in a system is zero.
• D. Sum of external forces are applied to a system is zero.

Explanation: This is a statement of the conservation of linear momentum, thus, it is a fact. For the sake of explanation, an external force would disturb the equilibrium of the system and produce an acceleration in the objects being tested.

Q150. What is true about the electric field and electric force?

• A. Electric field lines are towards negative and electron flow in same direction
• B. Electric field lines are towards positive and electron flow in opposite direction
• C. Electric field lines are towards the negative and electrons flow in the opposite direction.✓
• D. Electric field lines are positive and electrons flow in the same direction.

Explanation: Electric field lines always point away from a positive charge and towards a negative point. In fact, electric fields originate at a positive charge and terminate at a negative charge.This shows that OPTION B and D ARE INCORRECT. Electrons flow from lower potential terminal to higher potential terminal being negatively charged particles it flows from negative to positive poles hence it is the opposite direction as the electric field.So,OPTION C is incorrect.

Q151. The value of universal constant "R" is:

• A. 8.314 J mol-31K-3
• B. 1.38J mole-1 K-3
• C. 1.38J mole-1 K-1
• D. 8.314 J mole-1 K-1✓

Explanation: Physically, the gas constant is the constant of proportionality that relates the energy scale in physics to the temperature scale, when a mole of particles at the stated temperature is being considered. The value of R is 8.314J⋅K−1⋅mol−1

Q152. Two capacitors C1 = 2μF and C2 = 4μF, are connected in series across a 100 V supply. Find the effective capacitance:

• A. ½ μF
• B. 3/2 μF
• C. 5/2 μF
• D. 4/3 μF✓
• E. 2 μF

Explanation: 1/C=1/C1+1/C2 1/C=½ +¼ 1/C=¾ C=4/3. The effective capacitance is therefore 4/3 μF

Q153. Coal and petrol are stores of chemical energy when are burnt, chemical energy is converted into heat energy i.e chemical energy = heat energy + _.

• A. Electrical energy
• B. losses✓
• C. gains
• D. wind energy
• E. nothing

Explanation: When coal or petrol is burnt chemical energy stored in it is converted to heat energy and some of it is lost to the surrounding.

Q154. When there is an increase in the length of the simple pendulum then its time period will:

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

Explanation: According to formula: T = 2π√l/gTime period T is directly proportional to length l of the pendulum, hence increase in lenght would increase the time period. So, option D is correct.As the time period is dependent on lenght hence it would increase due to an increase in the length . So all options except D ate incorrect.

Q155. A neutron travels a distance of 24 m in a time interval of 3.6 x 10^-4 s. Assuming its speed was constant. Find its kinetic energy. Take 1.7 x 10^-27 kg as the mass of the neutron.

• A. 37.702 x 10^-19 joule✓
• B. 27.702 x 10^-19 joule
• C. 17.70 x 10^-19 joule
• D. 07.702 x 10^-29 joule

Explanation: speed of neutron = distance travelled by neutron / time taken by neutron for covered that distance . speed of neutron = 24/3.6 × 10-4 m/s speed of neutron ( V)= 6.6 × 10⁴ m/s now , kinetic energy = 1/2mv² K.E = 1/2 × 1.7 × 10-27 ×( 6.6 × 10⁴)² J = 1/2 × 1.7 × (6.6)² × 10-19 j =37.2 × 10-19 j so, K.E = 37.2 × 10-19. Hence the correct answer is A which is closest to the correct answer

Q156. Kilowatt-hour is a unit of?

• A. Electric Energy✓
• B. Power
• C. Momentum
• D. Torque

Explanation: The kilowatt-hour (SI symbol: kW⋅h or kW h; commonly written as kWh) is a unit of energy equal to 3600 kilojoules (3.6 megajoules). The kilowatt-hour is commonly used as a billing unit for energy delivered to consumers by electric utilities.

Q157. When frequency of applied periodic Force is equal to the natural frequency of harmonic oscillator then the _ of oscillator _.

• A. amplitude : decreases
• B. Amplitude : increases✓
• C. Frequency : increases
• D. Frequency : decreases

Explanation: This question refers to the phenomenon of resonance. During resonance, the amplitude keeps on increasing after every subsequent oscillation, provided the system is undamped.

Q158. The wavelength of the electromagnetic wave having frequency of 3 kHz will be?

• A. 120 km
• B. 100 km✓
• C. 80 km
• D. 140 km

Explanation: λ = v / f Inputting speed of light or 3 x 108 m/s as v and 3 x 103 Hz as f gives us 1 x 105 m or 100 km.

Q159. The sum of all forms of molecular energies (Kinetic and Potential) of a substance is termed as?

• A. Elastic energy
• B. Absolute energy
• C. Internal energy✓
• D. Heat energy

Explanation: Elastic energy is a form of potential energy. Absolute energy does not exist. By definition, Internal energy is the sum of total kinetic and potential energy as defined in 1st law of thermodynamics.

Q160. The rate at which work is being done is called:

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

Explanation: The rate at which work is done is called power. It is expressed as the amount of work per unit of time.

Q161. Energy consumed by 60 watt bulb in 2 minutes is equal to:

• A. 7.2 kilo joules✓
• B. 720 joules
• C. 120 joules
• D. 72000 joules

Explanation: 60 watt * 120s (2 mins) = 7200 watt-seconds = 7200J = 7.2 Kilo joules.

Q162. Which one of the following requires no medium?

• A. Beta rays
• B. Alpha rays
• C. Gamma rays✓
• D. All of these

Explanation: Out of all these, Gamma rays are an example of electromagnetic waves, which require NO medium to travel and propagate from one place to the other or even through a vacuum.On the other hand, mechanical waves require a medium to travel and propagate from one place to the other and can NOT pass through the vacuum. Examples of mechanical waves are sound waves, alpha rays, beta rays, etc.The picture attached represents the 'Electromagnetic Spectrum', of which 'Gamma Rays' are a part of.

Q163. An electric bulb is rated at 220 V, 100 W. What is its resistance?

• A. 250 Ohms
• B. 350 Ohms
• C. 450 Ohms
• D. 484 Ohms✓

Explanation: The correct answer is 484 Ohms.

Q164. The fractional change in resistance per kelvin is known as:

• A. Temperature coefficient of resistance✓
• B. Thermal coefficient
• C. Linear coefficient of expansion
• D. Volumetric coefficient of expansion

Explanation: The fractional change in resistance per kelvin is called the temperature coefficient. The resistance coefficient, abbreviated as K, a dimensionless number, is how much resistance to the flow an obstacle has. The volumetric coefficient increases in volume per unit original volume per Kelvin rise in temperature is called the coefficient of volumetric expansion. The ratio increase in length original length for the 1-degree rise in temperature is called the coefficient of linear expansion

Q165. Which of the following is an instrument for monitoring radiations:

• A. GM tube✓
• B. Radar
• C. Wilson cloud chamber
• D. Both A and C

Explanation: The Geiger-Mueller (GM) detector is a common portable instrument choice for a general laboratory radioactive material survey. GM detectors are capable of detecting alpha, beta, and gamma radiation. However, this instrument is limited by its ineffectiveness in detecting lower energy beta and gamma emitters. Radars send out electromagnetic waves as short pulses which may be reflected by objects in their path, in part reflecting to the radar. When these pulses intercept precipitation, part of the energy is scattered back to the radar. A cloud chamber, also known as a Wilson cloud chamber, is a particle detector used for visualizing the passage of ionizing radiation.

Q166. Which of the following is the pair of isobars?

• A. 1H1 and 2H1
• B. 12C6 and 13H6
• C. 2H1 and 3H1
• D. 30H15 and 30Si14✓

Explanation: Isobars are atoms of different elements having the same atomic mass but different atomic numbers. They have the same number of nucleons (protons + neutrons). They have different numbers of protons (or electrons).

Q167. Electrons are emitted in the production of X-rays by:

• A. Conduction
• B. Convection
• C. Thermionic emission✓
• D. None of these

Explanation: Electrons are emitted in the production of X rays by heating filament and this process is called thermionic emission and electrons are called thermions.

Q168. A battery whose emf is 40 V has an internal resistance of 5 Ohms. If this battery is connected to a 15 Ohms resistor ‘R’, what will be the voltage drop across ‘R’:

• A. 10 V
• B. 30 V✓
• C. 40 V
• D. 50 V
• E. 70 V

Explanation: 40 = I x (15+ 5) 40= I x 20 I = 40/20 I= 2 AVoltage drop across resistor R V= IR V= 2 x 15 V= 30 V (hence B is the correct option)

Q169. Due to the magnetic force, a positively charged particle executes uniform circular motion within a uniform magnetic field ‘B’. If the charge is ‘q’ and radius of its path is r, which of the expressions gives the magnitude of the particle’s linear momentum:

• A. qBr✓
• B. qB/r
• C. q/(Br)
• D. B

Explanation: Here the centripetal force will balance the magnetic force. So, mv2/r=qvB or mv=qBr Thus, linear momentum, p=mv=qBr

Q170. When a conductor of a cross-sectional area 5x10-6 m2 carries a current of 6 A, the drift velocity of the conduction electrons is 1.2 x 10-4 ms1-. What is the number density (number per unit volume) of the conduction electrons?

• A. 4x10-28 m-3
• B. 1.6x10-27 m-3
• C. 2.5x10-27 m-3
• D. 6.3x1028 m-3✓
• E. 1.3x1034 m-3

Explanation: The formula for electric current relating the drift velocity is: I = neAV Where; I = Electric current n = Number of charges per unit volume e = Electron charge A = Cross sectional area V = Drift speed Solving for 'n' : n = I/eAV Here I = 6.0 Amp e = 1.6 x 10-19 C A = 5.0 x 10-6 m2 V = 1.2 x 10^-4 m/s Put all these values inabove equation and do the calculations: n = (6.0)/ (1.6 x 10-19) (5.0 x 10-6) (1.2 x 10-4) n = 6.3 × 1028 m-3 is the answer

Q171. A battery has an e.m.f of 6.0 volts and an internal resistance of 0.4 ohm. It is connected to a 2.6 ohm resistor through a SPST (single pole, single throw switch): When the switch is closed, the potential difference between the terminal Is, in volts is:

• A. 0
• B. 0.8
• C. 2.6
• D. 5.2✓
• E. 6.0

Explanation: Total current = V/R= 6/3= 2V = IR2.6 x 2 = 5.2

Q172. The half-life of C14 is about:

• A. 1637 years
• B. 892 years
• C. 10 years
• D. 100 years
• E. 5730 years✓

Explanation: Carbon-14 has a half-life of 5,730 ± 40 years—i.e. half the amount of the radioisotope present at any given time will undergo spontaneous disintegration during the succeeding 5,730 years.

Q173. The half-life of C14 is approximately 5,730 years, while the half-life of C12 is essentially infinite. If the ratio of C14 to C12 in a certain sample is 25% less than the normal ratio in nature, how old is the sample?

• A. Less than 5,730 years✓
• B. Approximately 5,730 years
• C. Significantly greater than 5,730 years, but less than 11,460 years
• D. Approximately 11,460 years
• E. Approximately 15,730 years

Explanation: Because the half-life of carbon-12 is essentially infinite, a 25 percent decrease in the ratio of carbon-14 to carbon-12 means the same as a 25 percent decrease in the amount of carbon-14. If less than half of the carbon-14 has deteriorated, then less than one half-life has elapsed. Therefore, the sample is less than 5730 years old. Be careful with the wording here—the question states that the ratio is 25% less than the ratio in nature, not 25% of the ratio in nature, which would correspond to choice (D).

Q174. Which of the following statements is not consistent with Bohr's set of postulates regarding the hydrogen atom model with regard to the emission and absorption of light?

• A. Energy levels of the electrons are stable and discrete.
• B. An electron emits or absorbs radiation only when making a transition from one energy level to another.
• C. To jump from lower energy to higher energy, an electron must absorb a photon of precisely the right frequency such that the photon's energy equals the energy difference between the two orbits.
• D. To jump from a higher energy to a lower energy, an electron' absorbs a photon of frequency such that photon's energy is exactly the energy difference between the two orbits.✓
• E. None of the above

Explanation: To jump from higher energy to lower energy, an electron emits(not absorbs) a photon of frequency such that the photon's energy is exactly the energy difference between the two orbits. All other statements are consistent with Bohr’s postulates.

Q175. Sodium nucleus consists of 11 protons and 12 neutrons. The conventional symbol of this nucleus is?

• A. 11Na11
• B. 12Na12
• C. 11Na23✓
• D. 12Na23
• E. 12Na11

Explanation: The conventional symbol of the element contains the proton number(number of protons) and the mass number(proton number+number of neutrons), which is 11 and (11+12=)23, in this case. So the correct option is C. The conventional symbol of a sodium nucleus is 11Na23.

Q176. In free states, the mass of the nucleus is always:

• A. Greater than the mass of its constituents
• B. Equal to the mass of its constituents
• C. Less than the mass of its constituents✓
• D. Far greater than the mass of its constituents

Explanation: As mentioned earlier, the mass of the nucleus is slightly less than the sum of the masses of its individual constituents. This mass difference is known as the mass defect, which represents the mass converted into binding energy during the nuclear formation. The binding energy is the energy that holds the nucleus together and is released when nucleons (protons and neutrons) come closer and form a stable nucleus. Hence, option (c) is correct.

Q177. For the first time in 1914, Henry Moseley used X-rays for the determination of:

• A. Atomic Number✓
• B. Atomic Mass
• C. Molecular Mass
• D. Equiavalent mass

Explanation: In 1914, he observed and measured the X-ray spectra of various chemical elements using diffraction in crystals. Through this, he discovered a systematic relation between wave- length and atomic number. This discovery is now known as Moseley's Law.He found that certain lines in the x-ray spectrum of elements move to the same amount each time when we increase the atomic number by one.

Q178. Ohm multiplied by farad is equivalent to:

• A. Time✓
• B. Charge
• C. Distance
• D. Capacitor

Explanation: The formula for charging and discharging capacitor is RC=T R: resistance C: capacitance T: time for charging/ discharging

Q179. The time of open vibration of a simple pendulum may be decreased by:

• A. Increasing the length of the pendulum
• B. Decreasing the length of the pendulum✓
• C. Using a heavier bob
• D. Using a lighter bob

Explanation: The 'time of one vibration' of the simple pendulum can be decreased by decreasing the pendulum length. The period of simple pendulum is given by;T=,So there is direction relation between time period and length of pendulum. Therefore in order to decrease the time period the length of pendulum is decreased.Time period has nothing to concern with mass so option C & D are not related to the given question.

Q180. The velocity of an object increases from 0 to 10 m/s in 2 seconds. The distance covered by the object is _.

• A. 10 m✓
• B. 7.5 m
• C. 05 m
• D. 2.5 m

Explanation: Compute the value of acceleration, a, given that:Initial velocity=u=0Final velocity=v=10Time taken=t=2a=(u+v)/ta=(0+10)/2; a=5Now, use the equation:S=ut+0.5at2S=0+0.5(5)(22)S=10

Q181. e/m for an electron is _, when the charge of an electron is 1.6 x 10-19C and mass of electron is 9.1 x 10-31kg.

• A. 1.67 x 10-11 C/kg
• B. 1.76 x 1011 C/kg✓
• C. 16.7 x 1011 C/kg
• D. 1.76 x 10-11 C/kg

Explanation: The specific charge is being asked here. The formula for that is: Q/m {where Q is the charge of the electron and m is the mass.} Substitute Q= 1.6x10-19 and m=9.1x10-31 into the equation: =1.6x10-19/9.1x10-31 = 1.76x1011

Q182. If the velocity of a charged particle and magnetic field are at a fixed angle that is not 90 degrees, then the path will be:

• A. Circular
• B. Straight line
• C. Spherical
• D. Helical✓

Explanation: Force is given by F = qvBsinθ, where F, q, v and B are the force, charge on particle, velocity of particle and magnetic field strength respectively. θ is the angle between v and B. If θ = 0 or 180, there is no force on the particle and it continues to move with uniform velocity. If θ = 90, the force acting on the particle is maximum and perpendicular to the path of the particle. (force acts as a centripetal force and the particle moves along a circular path) When θ has a value other than 0, 90 or 180, the direction of velocity is either perpendicular or parallel to B. If the component of velocity is parallel to B it will not be affected by the magnetic field. However if the component of velocity is perpendicular to B it will be subject to a force of the magnetic field which would result in uniform circular motion. Hence the particle would have a component along a straight line as well as a circular component. Therefore the path would be in the form of a helix. And so option D is correct.

Q183. For which angle between area and magnetic field, the flux is maximum?

• A. 0 degree✓
• B. 90 degree
• C. 45 degree
• D. 60 degree

Explanation: According to the formula, ΦB = BAcosθWe know that cosθ gives its maximum value (1) when θ = 0°. ΦB = BAcos0° ΦB = BA(+1)ΦB = BAHence, option A is the correct option.

Q184. An armature coil consists of 30 turns of wire, each of area A = 0.05 m2 and total resistance of 10 Ω. It rotates in a magnetic field of 0.15 T at an angular speed of 84 radian per second. Determine the value of maximum induced EMF produced in the coil.

• A. 1 V
• B. 500 V
• C. 19 V✓
• D. 43 V

Explanation: Induced emf = NBA ω= 30 x 0.15 x 0.05 x 84 = 18.9 V

Q185. What is the SI Unit of EMF?

• A. Ohm
• B. Ampere
• C. Volt✓
• D. Newton

Explanation: This is a standard answer. The SI unit of EMF is Volts. Volts is also the SI unit of Potential difference. 1 Volt = Joule/Coulomb

Q186. Magnetic field lines have a property that lines are _.

• A. Non intersecting✓
• B. Intersect near south pole
• C. Intersect near north pole
• D. Intersect everywhere

Explanation: The magnetic field lines do not intersect, under normal conditions, without any external influences.

Q187. Laser light is?

• A. Multi-directional.
• B. Bi-directional.
• C. Uni-directional.✓
• D. None of these options is correct.

Explanation: The waves emitted from a laser are all in-phase and coherent. They are focused at one point and do not emit at an angle.

Q188. When electron series terminates on the 4th orbit _ series is obtained.

• A. Balmer
• B. Pfund
• C. Paschen
• D. None of these options is correct✓

Explanation: Bracket series is obtained when all transition of electron terminates on 4th orbit. Option A; balmer series is obtained when all transition of electron terminates on 2nd orbit. Option B: pfund series is obtained when all transition of electron terminates on 5th orbit. Option C: paschen series is obtained when all transition of electron terminates on 3rd orbit.

Q189. The energy of an X-ray quantum of wavelength 1.0 x 10-10 m is:

• A. 1.99 x 10-15 J✓
• B. 3 x 108 J
• C. 6.6 x 10-34 J
• D. 19.89 x 10-26 J
• E. 1.99 J

Explanation: ->v=fλ3 x 108=f x (1.0 X 10-10)f=3 x 108/1.0 X 10-10=3 x 1018->E=hfE=(6.62607004 × 10-34 )*(3 x 1018)=1.99 x 10-15

Q190. Candela is the luminous intensity, in the perpendicular direction of a surface _ square meter of a black body at the temperature of freezing platinum under a pressure of 101325 newtons per square meter.

• A. 1/300000
• B. 1/600000✓
• C. 1/900000
• D. 1/1200000
• E. 1/1500000

Explanation: The candela is the luminous intensity, in the perpendicular direction, of a surface of 1/600000 square meters of a blackbody at the temperature of freezing platinum under a pressure of 101325 newtons per square meter.

Q191. The series limit for the Balmer series of hydrogen spectrum occurs at 3664 A°. Calculate Ionization energy of hydrogen atom.

• A. 21.7 x 10-19 J
• B. 6.626 x 10-34 J
• C. 5.425 x 10-19 J✓
• D. 3664 x 10-10 J
• E. 3 x 108 J

Explanation: The Balmer emission lines correspond to transitions down to the level for which n=2. Given series is the Balmer series, so n1=2 and n2=∞ λ=3664A° Change in ionisation energy= Einfinity−E2= −E2 -E2 =-hc/λ -E2=6.626×10-34 ×3×10⁸/(3664x10-10) -E2 =−5.42×10−19 J so option C is the only correct option.

Q192. The phenomena in which certain metals emit electrons when exposed to high-frequency light is known as?

• A. Photoelectric Effect✓
• B. Compton’s Effect
• C. Henry's Effect
• D. Principle of Relativity
• E. Coulomb's Law

Explanation: When a metal surface is exposed to a monochromatic electromagnetic wave of sufficiently short wavelength (or equivalently, above a threshold frequency), the incident radiation is absorbed and the exposed surface emits electrons. This phenomenon is known as the photoelectric effect.

Q193. Minimum frequency below which no electrons are emitted from the metal surface is called _ frequency.

• A. Minimum
• B. Angular
• C. Maximum
• D. Threshold✓

Explanation: The minimum amount of frequency required to emit electrons from the surface of the metal is called the 'threshold frequency'.

Q194. 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.

Q195. Choose the odd one out:

• A. Eagle
• B. Cloud
• C. Squirrel✓
• D. Plane

Explanation: All Options excluding C refers to animals and objects that are involved in flying. Squirrel is the only option that is present on the ground.

Q196. Blueberries cost more than strawberries.Blueberries cost less than raspberries.Raspberries cost mre than strawberries and blueberries.If the first two statements are true, the third statement is:

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

Explanation: Explanation Because the first two statements are true, raspberries are the most expensive of the three.

Q197. 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: Explanation From 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.

Q198. Statement: I. The school authority has asked the FSC students to attend special classes to be conducted on Sundays. II. The parents of the FSC students have withdrawn their wards from attending private tuitions conducted on Sundays.

• 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 the statements I and II are independent causes
• D. Both the statements I and II are effects of some common cause

Explanation: The reason why parents have withdrawn their wards from attending private tuitions on Sunday is that the students had to attend special classes conducted by the school on Sunday. If there were no classes conducted by the school on Sunday then the parents wouldn’t have had to make their kids leave their Sunday tuitions.

Q199. From the following which word does not belong to the others:

• A. Index
• B. Book✓
• C. Glossary
• D. Chapter

Explanation: An index, glossary, and chapter are all parts of a book. Option A does not belong because the book is the whole, not a part.