Sindh Mdcat 2023 — Solved Past Paper with Answers

Q1. Identify the fragment in the following options:

• A. He went to the store
• B. Quickly, before the rain started.✓
• C. The cat is sitting on the window.
• D. She had a delicious meal.

Explanation: A sentence fragment is a sentence that is missing either its subject or its main verb.In the given options, "Quickly, before the rain started" is fragment as the sentence does not contain main verb and subject.Hence, option B is fragment.

Q2. Identify the sentence with the incorrect use of apostrophe:

• A. That is Mary's book.
• B. The dog's leash is in the car.
• C. Its a beautiful day outside.✓
• D. The children's toys are in the playroom.

Explanation: Its is used to show possession; whereas, it's is contracted form of "it is". Therefore, in option C "it's" should be used.

Q3. Which sentence demonstrates the correct use of past tense?

• A. She will go to the store yesterday,
• B. They will be eating lunch now,
• C. He had finished his homework before dinner,✓
• D. We are meeting them tomorrow

Explanation: Option C "He had finished his homework before dinner." is correct past tense.

Q4. Which of the following sentences has the correct word order?

• A. She usually goes for jogging in the evening.✓
• B. In the evening goes she usually for jogging.
• C. She goes to the usually for jogging evening
• D. Usually she for jogging goes in the evening

Explanation: "usually" which is adverb of frequency comes before verb and "in the evening" which is adverb of time comes after verb and object. Therefore, option A i.e., "She usually goes for jogging in the evening is correct."

Q5. What will be suitable response to the question: How was your day at school?'

• A. I'm going to the park
• B. My favorite subject is math
• C. It was great, thanks for asking✓
• D. I don't like school

Explanation: Option C i.e., "It was great, thanks for asking." is most suitable response to the question: "How was your day at school?". Other options are irrelevant to the given question.

Q6. Identify the error in the sentence: "His the car is red."

• A. It's a correct sentence
• B. The article "His" is unnecessary.
• C. The word order is incorrect; it should be "His car is red."✓
• D. The adjective "red" should be "blue'

Explanation: Option C is correct, "the" should not be placed after his; therefore, eliminated. The correct sentence will be; His car is red.

Q7. What is the antonym of "generous"?

• A. Selfish✓
• B. Charitable
• C. Benevolent
• D. Kind

Explanation: antonyms of "generous" include selfish, meager, small, uncharitable, acquisitive, frugal, petty etc. Hence, option A is correct.

Q8. The Sun began to _ behind the mountains, casting a warm and beautiful glow across the valley.

• A. rise✓
• B. set
• C. shine
• D. sleep

Explanation: The Sun began to rise behind the mountains, casting a warm and beautiful glow across the valley is correct sentence. Hence, option A is correct.

Q9. After a long day at work, Sarah found _ In her favorite book, escaping into a captivating world.

• A. solace✓
• B. chaos
• C. endurance
• D. agony

Explanation: According to the meaning of sentence "solace" suits best with the given statement, because the sentence before and after comma usually have opposite meaning. Since, the first part is "After a long day at work" it should be followed by a word that represents comfort or relief which is solace. Hence, option A is correct.

Q10. Identify the sentence with incorrect use of punctuation.

• A. I'm going to the store: do you need anything?
• B. I'm going to the store, do you need anything?
• C. I'm going to the store do you need anything?
• D. "I'm going to the store, do you need anything?"✓

Explanation: The given sentence should not contain quotation mark. Hence option D is incorrect sentence.

Q11. Which sentence has correct grammatical and stye structure?

• A. They're playing soccer✓
• B. The playing soccer
• C. Their playing soccer
• D. They have play soccer

Explanation: They're playing soccer is correct. option B: The is used Option C: Their is used Option D: have play is used. Hence, option A is correct.

Q12. Choose the sentence with correct use of apostrophe in possessives:

• A. The cats toys are in the corner.
• B. The cat's toys are in the corner.✓
• C. The cats' toys are in the corner
• D. The cars' toys' are in the corner

Explanation: Option B: The cat's toys are in the corner is correct. Option A: cats toys is incorrect Option C: cats' toys is incorrect Option D: cats' toys' is incorrect.

Q13. Which article should be used in the blank to make the sentence grammatically correct. "He lives in _ old house"

• A. a
• B. an✓
• C. the
• D. Blank

Explanation: Since, "old" begins with "o" which has a vowel sound, "an" should be used. Hence, option B is correct.

Q14. Identity the mistake in the use of prepositions in the following sentence:She is good at cooking in the kitchen.

• A. It's a correct sentence✓
• B. The preposition at" should be omitted
• C. The preposition "in" should be "on"
• D. The preposition "cooking" should be "to cook"

Explanation: The given sentence is a correct sentence. Hence, option A is correct.

Q15. Which sentence demonstrates correct subject-verb agreement?

• A. The cat are sleeping.
• B. The cats is sleeping.
• C. The cats has sleeping.
• D. The cats are sleeping.✓

Explanation: The cats are sleeping is correct answer. Option A: the cat are is incorrect. Option B: the cats is sleeping is incorrect. Option C: the cats has sleeping is incorrect.

Q16. Nobody known when fiction started, Perhaps, the first story teller was a prehistoric mother trying to explain the world to her children or maybe it was a hunter talking about his adventure around the compfire, Who can tell? What we do know, though, is that story-telling was a purely activity around 800 BC .Myths and tales were passed down by word of mouth and hod to be popularized by each new generation of story tellers. This oral tradition only example of Homer a professional story teller who lived in the eighth century BC. The contextual meaning of fiction is:

• A. Narrative✓
• B. Textbook
• C. Prose
• D. Truth

Explanation: According to given passage, the contextual meaning of fiction should be narrative. Hence, option A is correct.

Q17. Nobody knows when fiction started, Perhaps, the first story teller was a prehistoric mother trying to explain the world to her children or maybe it was a hunter talking about his adventure around the campfire, Who can tell? What we do know, though, is that story-telling was a purely activity around 800 BC .Myths and tales were passed down by word of mouth and got to be popularized by each new generation of story tellers. This oral tradition only example of Homer a professional story teller who lived in the eighth century BC.Myths were passed down by:

• A. written scriptures
• B. carved activity
• C. by word of mouth✓
• D. inscribed activity

Explanation: According to line 4 of given passage, myths were passed down by word of mouth. Hence, option C is correct.

Q18. Nobody known when fiction started, Perhaps, the first story teller was a prehistoric mother trying to explain the world to her children or maybe it was a hunter talking about his adventure around the compfire, Who can tell? What we do know, though, is that story-telling was a purely activity around 800 BC .Myths and tales were passed down by word of mouth and hod to be popularized by each new generation of story tellers. This oral tradition only example of Homer a professional story teller who lived in the eighth century BC. It is stressed In the passage that story-telling:

• A. began as a written activity
• B. became far more popular with the invention of writing
• C. was first introduced by Homer in ancient times
• D. possibly began in prehistoric times✓

Explanation: According to 1st line of given passage, the story-telling possibly began in prehistoric times. Hence, option D is correct.

Q19. Which of the following best characterizes the viruses with un-enveloped plus- (I point) strand RNA?

• A. Lacking envelope✓
• B. Having DNA
• C. Act indirectly:
• D. Enveloped

Explanation: Lacking envelope: As indicated by their name, un-enveloped plus-strand RNA viruses lack envelopes and consist only of a nucleic acid core capsid surrounded by protein viruses. Hence, this option is correct

Q20. Through which of the following does rabies spread?

• A. Cat
• B. Fox
• C. Dog✓
• D. Pig

Explanation: Rabies is most often spread by small, mammals such as dogs, racoons and foxes, most commonly by dogs. The rabies virus is spread by the saliva of the host animal, often after bites but it can also be contracted from handling a dead infected animal.

Q21. The hepatitis which pass from mother to her child during pregnancy is:

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

Explanation: Hepatitis C: Hepatitis C passes through blood transfusions, from mother to child during pregnancy and by sexual contact.

Q22. A virus enters into the body of host & intends to produce DNA from RNA.Which enzyme is required for this process?

• A. Transcriptase
• B. Reverse transcriptase✓
• C. Oxidoreductase
• D. Ligases

Explanation: Reverse transcriptase is responsible for conversion of single stranded RNA into double stranded DNA. Hence this option is correct.

Q23. Which of the following is the end product of anaerobic respiration?

• A. Methyl alcohol
• B. Acetaldehyde
• C. Formaldehyde
• D. Ethyl alcohol✓

Explanation: Each pyruvic acid molecule produced during glycolysis is converted to ethyl alcohol in two steps. In the first step pyruvic acid is decarboxylated under the action of enzyme to produce acetaldehyde, a two carbon molecule. NADH+H+ reduces acetaldehyde to ethyl alcohol. CH3.CO.COOH → CH3.CHO + CO2 CH3.CHO + NADH + H+ → CH3.CH2.OH + NAD+

Q24. What's the importance of krebs's cycle?

• A. Production of amino acids
• B. Production of vitamins
• C. production of ATP molecules through oxidative phosphorylation✓
• D. Production of pyruvic acid

Explanation: During step 3,4 and 8 of Krebs' cycle, 3 molecules of NADH + H+ are produced by oxidative decarboxylation of isocitrate, alpha-ketoglutarate and malate respectively. These NADH + H+ molecules are converted into ATP molecules by oxidative phosphorylation. Hence this option is correct.

Q25. The acceptor of carbon dioxide in Calvin cycle Is:

• A. RuBP✓
• B. RuMP
• C. PGA
• D. PGAL

Explanation: Ribulose bisphosphate (RuBP) is generally referred to as CO2 acceptor because it is capable of combining with carbon dioxide with the help of Ribulose bisphosphate (RuBP) carboxylase/oxygenase also known as RuBisCO.

Q26. Anaerobic respiration compared to aerobic respiration, it produces?

• A. More ATPs
• B. Less ATPs✓
• C. Equal ATPs
• D. Does not produce ATPs

Explanation: During anaerobic respiration, the pyruvic acid molecules are converted either to lactic acid or ethanol with release of very small amount of energy i.e. just 2 ATPs.

Q27. In carbohydrate hydrogen & oxygen are mostly in the same ratio i.e. 2:1 that's why they are called:

• A. carbon monoxide
• B. carbon dioxide
• C. hydrated carbons✓
• D. Triose

Explanation: Carbohydrates are a group of organic compounds having carbon, oxygen and hydrogen, inwhich hydrogen and oxygen are mostly found in the same ratio as in water i.e. 2:1 and are thus called hydrated carbons.

Q28. How much of temperature (°C) rise will be observed, as per the definition of specific capacity, if energy is used to raise the temperature of 1 gram of a substance?

• A. 1°C✓
• B. 2°C
• C. 3°C
• D. 10°C

Explanation: The specific heat capacity of a substance is a measure of the amount of energy needed to raise the temperature of 1 gram of that substance by 1°C. STB- Pg 20

Q29. The chemical compound has the same percentage (%) in the bacterial as well as the mammalian cell:

• A. Carbohydrates
• B. Protein
• C. Lipid
• D. Water✓

Explanation: The percentage of water in both bacterial and mammalian cell is 70%.Hence, this option is correct.

Q30. Glyceraldehyde & dihydroxy acetone are example of:

• A. Triose✓
• B. Tetrose
• C. Pentose
• D. Hexose

Explanation: Trioses are type of monosaccharides containing 3 carbon atoms. They include glyceraldehyde and dihydroxyacetone. Hence, this option is correct.

Q31. The one molecule of fatty acid forming ester bond with one molecule of long chain alcohol is:

• A. Saturated acylglycerol
• B. Unsaturated acylglycerol
• C. Phospholipids
• D. Waxes✓

Explanation: Waxes are simple lipids having one molecule of fatty acid forming ester bond with one molecule of long chain alcohol e.g Bee's wax. Hence, this option is correct.

Q32. Lysozyme represent this basic structural level of protein is:

• A. Primary structure
• B. Secondary structure
• C. Tertiary structure✓
• D. Quaternary structure

Explanation: Lysozyme possesses tertiary structure. Hence, this option is correct.

Q33. Which of the following compound is regarded as the precursor of many hormones like testosterone, progesterone and estrogens?

• A. Wax
• B. Cholesterol✓
• C. Phospholipids
• D. Acylglycerol

Explanation: One of the most important steroid is Cholesterol, a component of animal cell membrane and a precursor for the synthesis of a number of steriods, sex hormones such as testosterone, progesterone and estrogens. Hence, this option is correct.

Q34. Which one is the power house of cell?

• A. Ribosomes
• B. Golgi Apparatus
• C. Mitochondria✓
• D. Chloroplasts

Explanation: on the cristae of mitochondria are located enzymes and co-enzymes by means of which carbohydrates (starch), fatty acids (lipids) and amino acids (lipids) are metabolized to CO2 and H2O. Energy in the form of ATP is released in this process which is stored within mitochondria. ATP is energy rich compound and it provides energy for various cellular activities. Hence, "mitochondria" is known as "Power-House" of cell. Hence, this optopn is correct.

Q35. A phospholipid molecule has a head and two tails. Where are the tails found?

• A. As the surface of membrane
• B. In the interior of the membrane✓
• C. In the exterior of the membrane
• D. Spanning of the membrane

Explanation: The phospholipid molecule consists of two parts; hydrophobic tails and hydrophilic head. The hydrophilic head is present on the surface of the membrane while hydrophobic tails are present in the interior of the membrane.

Q36. Which of the following may lead to the death by the age of three years?

• A. Baucher disease
• B. Gaucher's disease
• C. Tay-Sachs disease✓
• D. Krabbe's disease

Explanation: It lead to mental retardation, blindness, death by age 3. Hence, this option is correct.

Q37. Which of the following best describes the plasma membrane?

• A. Adhesible
• B. Permeable
• C. Impermeable
• D. Semipermeable✓

Explanation: The plasma membrane performs several functions but the main and the most important functions are protection of cell cytoplasm to regulate the flow of solutions and material in an out of the cell with certain limitation. These limitations or checkin lowacross the membrane is called differential or selective permeability. Therefore, plasma membrane is called semipermeable membrane.

Q38. What is the cementing layer between two daughter cells called?

• A. Primary wall
• B. Secondary wall
• C. Middle lamella✓
• D. Cell membrane

Explanation: The firstformed cell plate works as a cementing layer between two daughter cells and is called middle lamella. Hence, Option C is correct.

Q39. Protein layers is embedd in lipid bilayers, this was explained by:

• A. Lock and key Model
• B. Induced fit model
• C. Fluid mosaic model✓
• D. Sandwich model

Explanation: Fluid mosaic model: According to the fluid mosaic model, the lipid bilayer is retainedas the core of the membrane. The structure and arrangement of membrane proteins in the fluid-mosaic model are like icebergs in the sea. The proteins occur as a 'mosaic' of discontinuous particlest that penetrate deeplyinto and even completely through thel lipid sheet. Hence, this option is correct.

Q40. Just given function is associated with lysosomes:

• A. Protein synthesis
• B. Processing & packaging
• C. Intracellular digestion✓
• D. Lipid synthesis

Explanation: Lysosomes are concerned with intracellular digestion. Hence, this option is correct.

Q41. How long does it take in action potential to occur?

• A. Few minutes
• B. Few milliseconds✓
• C. Few hours
• D. Few seconds

Explanation: Action potential is a temporary localized reversal of the polarity of the neurolemma, which occurs when neurolemma is stimulated (e.g.electric shock, touch, sound, vibrations etc). During the action potential, the polarity of neurolemma first changes to +40mv (i.e.depolarization) and then restores to -65mv again (i.e. repolarization) This action is extremly rapid as it occurs only in a few milliseconds. to happen. Hence, option B is correct.STB- Pg 67.

Q42. This part of brain involve in carrying long term memory:

• A. Hippocampus✓
• B. Cerebellum
• C. Cerebrum
• D. Pons

Explanation: Hippocampus is involved in storage of long term memory. Hence, this option is correct.

Q43. A reflex involving sensory and a motor neuron the way such transmission is called:

• A. Synapse
• B. Mono synaptic✓
• C. Reflex arc
• D. Synaptic cleft

Explanation: According to STB, B is correct. Option A: Synape: The region where the impulse moves from one neuron to another is called synapse. Option B: Mono synaptic: A reflex involves usually two neurons, a sensory and a motor neuron. The pathway of such transmission is reflex arc. In this case, since only one synapse is involved, so such reflex is called mono synaptic. Option C: Reflex arc: The pathway of such transmission is reflex arc. Option D: Synaptic cleft: The space between two neurons across which the impulse is transmitted by a neurotransmitter is known as synaptic cleft.

Q44. These are required for the impulse to transfer from presynaptic to post-synaptic neuron:

• A. Sodium
• B. Potassium
• C. Calcium✓
• D. Proteins

Explanation: Calcium ions cause the vesicles containing neurotransmitter to fuse with the axon terminals and release the neurotransmitter into the synaptic cleft. The neurotransmitters bind to the receptors on the post synaptic membrane, which generate action potential in the post-synaptic cell. Hence, option C is correct.

Q45. Which of the following function dopamine serves?

• A. ransmission blocker
• B. Neurotransmitter✓
• C. Anesthesia
• D. Sedative

Explanation: Dopamine along with acetylcholine, norepinephrine (noradrenaline), glycine, gaba, serotonin, etc. act as neurotransmitters. Hence, option B is correct.

Q46. Which part of the brain is responsible for higher cognitive functions such as thinking reasoning and problem solving?

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

Explanation: The cerebrum is responsible for thinking, reasoning and problem solving. Hence, this option is correct.

Q47. What is formed, when the blastula folds inwards?

• A. Morula
• B. Blastocoel
• C. Blastopore
• D. Gastrula✓

Explanation: The next stage followed by blastula is called gastrula and process of its formation is called gastrulation. During this process, cells of blastula migrate inwards and their rearrangment at different locations in the embryo occurs. Hence, this option is correct.

Q48. Which phenomenon describes the production of asexual form by sexual form and vice versa?

• A. Colony
• B. Alternation of generation✓
• C. Parasitism
• D. Polymorphism

Explanation: The life cycle during which one life form (asexual) alternates with other life form (sexual) is known as alternation of generation. Hence, this option is correct.

Q49. Which of the following describes coral reefs used by Hakeem in preparing eastern medicines?

• A. Diamond
• B. Emerald
• C. Ruby
• D. Marjan✓

Explanation: Red coral by the name of 'MARJAN' is used by Hakeems in preparing eastern medicines. STB Pg 201.Hence, option D is correct.

Q50. Evolutionary progress towards formation of organ system in cnidarians includes development of enteron and:

• A. Rudimentary network of nerves✓
• B. Symmetry
• C. Cnidocytes
• D. Cellular organization

Explanation: The development of an enteron and a rudimentary network of nerves in cnidarians is the first evolutionary step towards formation of the organ system. STB PG- 199.Hence, option A is correct

Q51. What's the optimum pH of pepsin in stomach?

• A. 3
• B. 2
• C. 2.5
• D. 1.4✓

Explanation: Pepsin of the stomach has an optimum pH of 1.4. It is inactive in neutral or alkaline solution. STB- Pg 47.Hence, option D is correct.

Q52. At equilibrium, a scientist added more substrate and observed an increase in the rate of the reaction which soon declined. He added some more substrate but this time the rate of the reaction remain unaffected. What was the reason?

• A. Enzyme did not function
• B. Feedback due to the accumulation of the end product✓
• C. Enzyme was more than substrate's active sites
• D. substrate's did not function

Explanation: The addition of more substrate initially increased the rate of the reaction. However, as the reaction progressed, the products of the reaction may have accumulated and triggered a feedback mechanism that inhibited the reaction, maintaining it at a steady rate. This mechanism is called feedback inhibition. "Feedback inhibition is a process in which the reaction is controlled by the end product."Hence, option B is correct.

Q53. Penicillin blocks the active sites of an enzyme that many bacteria use in making cell wall. It is an example of:

• A. Competitive inhibition✓
• B. Incompetative inhibition
• C. Feedback inhibition
• D. Radiation effect

Explanation: Option B should be non competitive inhibition instead of incompetitive inhibition. Option A: Competitive inhibition: Many antibiotic are inhibitors of specific enzyme in bacteria e.g. penicillin blocks the active site of an enzyme that many bacteria use tomade cell-walls. These antibiotics are example of competitive inhibition. Hence, this option is correct.

Q54. The structure of an enzyme is altered by:

• A. Irreversible inhibition
• B. Reversible inhibition
• C. Competitive inhibition
• D. Non competitive inhibition✓

Explanation: Non-competitive inhibitors obstruct enzymatic reactions by binding to a part of enzyme away from the active site. This interaction causes the enzyme molecule to change its shape, rendering the active site unreceptive to substrate, or leaving the enzyme less effective at catalyzing. Hence this option is correct.

Q55. Chemical substance that can react with an enzyme faster than real substrate and without produce a product is:

• A. Accelerator
• B. Inhibitor✓
• C. Coenzyme
• D. Activator

Explanation: Inhibitors are substances that react with enzyme in place of substrate but are not converted into product.

Q56. Which of the following is a good evidence of an evolutionary pathway leading from reptiles to birds?

• A. Mammals
• B. Fishes
• C. Archaeopteryx✓
• D. Arthropods

Explanation: Archaeopteryx is thought to be earliest bird whose fossils have been found from rocks 150 million years old. With the exception of feathers, these birds showed resemblance to the dinosaurs (giant reptiles of past). Hence, option C is correct.

Q57. The evolution of birds has long been a difficult issue for biologists until the discovery of the Archaeopteryx fossil in 1861. This ancient bird exhibited teeth, a long tail containing 20 vertebrae and wings with movable finger and claws. In the light of mentioned facts who were the ancestors of the birds?

• A. Insects
• B. Pisces
• C. Amphibians
• D. Reptiles✓

Explanation: With the exception of feathers, archaeopteryx showed resemblance to the dinosaurs (giant reptiles of past). Hence, option D is correct.

Q58. The artificial selection in breeding provides a strong evidence for evolution. What does this term means?

• A. Vestigial organ
• B. Domestication✓
• C. Mutation
• D. Homology

Explanation: Domestication means artificial selection in breeding provides evidence for evolution. Example: Vast diversity has been achieved in domestic dogs and pigeons by artificial selective breeding procedure over a short period of time by man This is evidence that evolution is possible. STB- PG 232

Q59. Carolus Linnaeus was the believer of:

• A. Catastrophism
• B. Inheritance of acquired characters
• C. Natural selection
• D. Special creation✓

Explanation: Special creation is correct. Carlous Linnaeus was the believer of special creation. According to this theory; " God created all plants and animals" i.e., all living beings came into existance in their present forms. STB- Pg 222.

Q60. What is the volume of blood pumped per minute by the left ventrical into the system circuit called?

• A. Cardiac output✓
• B. Systole
• C. Atrial system
• D. Ventricular system

Explanation: Cardiac output is correct. The volume of blood pump per minute by the left ventricle in to the system circuit is called cardiac output.

Q61. Which enzyme is secreted in an inactive state, to prevent it from digesting in own cells?

• A. Laetase
• B. sucrase
• C. Maltase
• D. Pepsin✓

Explanation: Pepsin is a powerful protein digesting enzyme and is quite capable of destroying cell's internal structure and thus is produced in inactive form pepsinogen from by the cell. It is converted into its active form only in the digestive tract where it is required to be active.Hence, option D is correct.

Q62. Carnivorous adaptation of plants, due to relatively low content of:

• A. Nitrogen✓
• B. Potassium
• C. Sulphur
• D. Calcium

Explanation: Carnivorous plants live in environments where there is deficiency of nitrogen, in order to supplement their diet with nitrogen, they trap insects or other small animals and digest them by enzymes or by bacterial decomposition, and absorb the nitrogenous compounds thus formed.Thus option A, is correct.

Q63. In nutritional terms, what among the following is sundew you categorized?

• A. Autotrophic
• B. Heterotrophic
• C. Holazoic
• D. Partially autotrophic/partially heterotrophic✓

Explanation: Sundew plants are partly autotrophic, using photosynthesis for energy, and partly heterotrophic, capturing and digesting insects to obtain essential nutrients.Hence, option D is correct.

Q64. Which of the following statements is correct about semilunar valves?

• A. Present in veins to prevent backward flow✓
• B. Present in arteries to regulate jerks in pulsations
• C. Present in capillaries to regulate flow of blood
• D. Present in aorta to prevent backward flow

Explanation: Semilunar valves are present in veins to prevent backflow of blood in veins. Other blood vessels like arteries, capillaries do no have valves in them. Aorta also have semilunar valves but they are known as 'aortic semilunar valves'. Since only semilunar valves is written, we selected 'veins' as correct option.

Q65. The total capacity of a human lung is 5 litres. What percentage of it is filled when one takes and extra deep breath?

• A. 10%
• B. 40%
• C. 60%
• D. 80%✓

Explanation: The total average lung capacity of adult human being is about 5 liters of air. With an extra deep breath, the maximum value of air inspired and expired called vital capacity averages about 4 liters, which is 80% (⅘ ×100 =80%).

Q66. Earthworm is an example of:

• A. Detritivores✓
• B. Fluid feeder
• C. Macrophagous
• D. Microphagous

Explanation: Earthworms are detritivores because they primarily feed on dead organic matter. They consume this detritus and break it down into nutrient-rich castings through their digestive processes. Hence, option A is correct.

Q67. Photosynthesis bacteria utilise H2S instead of water and liberate one of the following instead of oxygen:

• A. Sulphur✓
• B. Phosphorus
• C. Calcium
• D. Magnesium

Explanation: Photosynthetic bacteria is mistakenly typed as photosynthesis bacteria. Option A: Sulphur is correct. Photosynthetic bacteria utilize H2S instead of water and liberate sulfur instead of oxygen. CO2 + H20 → (CH2O)n + H2S + 2S STB Pg 105.

Q68. Which of the following are the genetically engineered bacteria that are used to make human growth hormone and insulin for diabetics?

• A. Pneumococcus
• B. E. Coli✓
• C. Rhizobium
• D. Nost

Explanation: E.coli is correct. E. coli has been programmed to make human growth hormones for the treatment of growth deficiencies and insulin for diabetics. STB Pg 109

Q69. Bacterial cell wall made-up of:

• A. Cellulose & pectin
• B. Cellulose & cutin
• C. Hemicellulose & chitin
• D. Amino acid & sugar✓

Explanation: Amino acids and sugar is correct. Cell-wall of bacteria is totally different from ordinary plant cell-wall. It is chemically complex and made up of amino acids, sugar and chitin but cellulose is totally missing. The cell-wall of most bacteria have unique macromolecule called peptidoglycan. It is composed of long glycan chains cross-linked with peptide fragments. In addition sugar molecules, teichoic acid, lipoprotein and lipopolysaccharides are also present. STB- Pg 102.

Q70. It serves as vector in genetic engineering:

• A. Plastids
• B. Plasmid✓
• C. Nucleoid
• D. Pills

Explanation: Option D is pili not pills. Plasmid is small fregment of extra genetie material double stranded DNA. It is self replicating and not associated with growth and metabolism. Plasmids serve as vectors in genetic engineering. STB Pg 102.Hence, option B is correct.

Q71. Membranous infoldings in bacteria that initiate DNA replication is:

• A. Mesosomes✓
• B. Peroxisomes
• C. Glyoxysomes
• D. Nucleosomes

Explanation: Mesosomes are invaginations of cell-membrane into the cytoplasm. Mesosomes are in the form of vesicles, tubules or lamellae. Their function is to help in DNA replication, cell-division, respiration and in export of enzymes. Hence, Option A is correct. STB Pg 102.

Q72. Testes developed inside the abdomen. In which of the following structure do they lie before birth?

• A. Sac
• B. Scrotum✓
• C. Pouch
• D. Vesicle

Explanation: Scrotum is correct. The male gonads are a pair of testes (singular-testis). Though they develop inside the abdomen but come to lie, before birth, in scrotum. STB Pg- 112.

Q73. In the process of ovulation, which of the following sactures sucks the egg released from alternate ovary, every month

• A. Oviducts✓
• B. Uterus
• C. Vagina
• D. Ureter

Explanation: During ovulation one egg is released from the alternate ovary into the body cavity, which is immediately sucked up into an oviduct. STB Pg-113. Both the oviducts open at their other end into a small pear shaped mascular but distensible sac the uterus in which the embryo develops. At the bottom of uterus is a cervix that leads into muscular tube called vagina, which is narrow opening used for the reciaption of sperms and delivery of foetus.

Q74. After ovulation Graaf follicle converts into:

• A. Corpus callosum
• B. Corpus albicans
• C. Corpus luteum✓
• D. Corpus atresia

Explanation: Corpus luteum is correct.Under action of LH, ruptured follicle changes into a yellowish body called corpus luteum, which produces progesterone. STB Pg 117.

Q75. Fertilization of ovum takes place in rabbit, man and other placental mammals in:

• A. Ovary
• B. Uterus
• C. Cervis
• D. Fallopian tube✓

Explanation: Fallopian tube is correct.Fertilization of ovum takes place in proximal part of fallopian tube, also known as oviduct.

Q76. Corpus luteum in mammals occur in:

• A. Brain & connects the two cerebral hemispheres
• B. Ovaries & produces progesterone hormones✓
• C. Heart & initiate arterial connection
• D. Skin & acts as a pain receptor

Explanation: Ovaries and produces progesterone hormones is correct. Under action of LH, ruptured follicle changes into a yellowish body called corpus luteum, which remains inside the ovary and produces progesterone.STB Pg 117.

Q77. How are the ribs attached to vertebrae?

• A. Fixed joints
• B. Moveable joints
• C. Hall & socket joints
• D. Partially movable joints✓

Explanation: Partially moveable joints is correct. Partially moveable joints allow a little movement the ribs are attached with vertebrate by partially movable joints these joints permit your ribs to move up and down while you breathe. STB Pg 39. Immovable or fixed joints connect the bones of skull in the form of case to protect the brain.Moveable joints include hinge joint and ball and socket joints. Hinge joints are found and elbow and knee while ball and socket joints are shoulder and hip joints.

Q78. Which cavities are present around the joints and contain a thin oily fluid the reduces friction and keeps the joints moving freely?

• A. Synovial✓
• B. Ventricles
• C. Acetabulum
• D. Deltoid ridge

Explanation: Synovial is correct. Synovial cavities are present around the joints containing a thin oily synovial fluid that reduces the friction around the joints. Highly movable joints like that of elbow or a knee and a shoulder or hip joint also need lubrication and cushioning to prevent the adjoining bone crushing with each other. STB Pg- 40.

Q79. This muscle controls the diameter of your blood vessels:

• A. Smooth muscles✓
• B. Striated muscles
• C. Cardiac muscles
• D. Skeletal muscles

Explanation: Smooth muscles is correct. Smooth muscles push the food through the digestive tract, they empty your urinary bladder, and the control the diameter of the blood vessels, the diameter of the pupil of your eye and the state of the erection. of hair of the skin STB Pg-43

Q80. When Mendel crossed together two contrasting homozygous individuals, the phenotype of the hybrid in F1 cross appeared to be that of:

• A. Recessive parent
• B. Dominant parent✓
• C. Indifferent
• D. Half dominant & recessive

Explanation: Dominant parent is correct. When Mendel crossed two contrasting homozygous individuals, all the offsprings of G1 generation were of dominant phenotype. For example, crossed between round and wrinkled seeded plants produced plants with round seeds in F1 generation.STB- Pg 184.

Q81. If a dihybrid cross is made between pisum sativum plants having Yellow/Round and Green/Wrinkled seeds. Results of F2 generation show:

• A. Yellow/Round- 3/16
• B. Yellow/Wrinkled-3/16
• C. Green/Round-3/16✓
• D. Green/Wrinkled 1/16

Explanation: As shown in the figure below, the round green offsprings are 3 out of 16 offsprings. Hence option c is correct.

Q82. If a dihybrid cross is made between pisum sativum plants producing Yellow/Round and Green/Wrinkled seeds. Results of F2 generation show: Yellow/Round- 9/16 Yellow/Wrinkled-3/16 Green/Round-3/16 Green/Wrinkled 1/16 Which ratios of these results confirm independent assortment had taken place?

• A. 09/16
• B. 03/16
• C. 1/16
• D. 3/16 & 3/16✓

Explanation: 3/16 & 3/16 is correct. As round green and yellow wrinkled are recombinant types and are not parental types. It shows that the genes are not bound to be inherited together, either gene can be inherited independent of the other. This shows that independent assortment has taken place.

Q83. An orthopedic specialist observed the X-ray of the joint of a patient and detected hardening of the cartilage due to excess calcium deposit. Consequently, the joint was very stiff and crippled the patient. What was the patients suffering from?

• A. Dise slip
• B. Sponfylosis
• C. Arthritis✓
• D. Sciatica

Explanation: Arthritis is correct. Arthritis is characterized by stiffening of joints, pain, and less mobility of joints.

Q84. Which of the following is a disease in which the blood fails to clot?

• A. Colour blindness
• B. Haemophilia✓
• C. Diabetics
• D. Alkaptonuria

Explanation: Heamophilia is correct. Haemophilia occurs if any blood clotting factor is either faultt or absent. In this case blood of the patient fails to clot and person dies due to blood loss.

Q85. In humans beings multiple alleles control inheritance of:

• A. Blood groups✓
• B. Phenylketonuria
• C. Colour blindness
• D. Sickle cell anemia

Explanation: Blood groups is correct. A gene for a trait having three more allelic forms are called multiple alleles. A well known example is that of blood groups. STB Pg- 190. Phenylketonuria, color blindness and sickle cell anemia are controlled by single genes.

Q86. Polygenic inheritance forms the bases of:

• A. Codominance
• B. Incomplete dominance
• C. Continuous variation✓
• D. Discontinuous variation

Explanation: Continuous variation is correct. Polygenic inheritance forms the basis of continuous variations. STB Pg 193.

Q87. Mr. X & Mrs. X have same genotype i.e., IAi for blood group. What is the expected probability of the blood group of their children?

• A. Blood Group 'A-1.00, Blood Group 'O'-0.00
• B. Blood Group 'A'-0.75, Blood Group 'O'-0.25✓
• C. Blood Group 'A-0.50, Blood Group 'O'-0.50
• D. Group 'A- 0.25, Blood Group 'O'-0.75

Explanation: The cross between I^A i and I^A i will produce 3 offsprings with blood group A and one offspring with blood group O. So the probability will be;Blood group 'A' = ¾ = 0.75Blood group 'O' = ¼ = 0.25.So, option B is correct.

Q88. Which of the following reactions can be used for the conversion of ethyl alcohol into acet aldehyde?

• A. Polymerization
• B. Dehydrogenation✓
• C. Esterification
• D. Reduction

Explanation: Ethyl alcohol on dehydrogenation gives acetaldehyde. Hence, option B is correct.

Q89. Which of the following Is formed when excess of ethyl alcohol is treated with concentrated H2SO4 at low temperature?

• A. Diethyl ether✓
• B. Dimethyl ether
• C. Ethene
• D. Acetylene

Explanation: When ethyl alcohol reacts with conc.H2SO4 at low temperature (140°C), it gives diethyl ether. Hence option A is correct.

Q90. Which of the following will give lodoform reaction on the treatment with Na2CO3 and I2?

• A. Methanol
• B. Acetic Acid
• C. Acetic Anhydride
• D. Acetone✓

Explanation: Only acetaldehyde, ethanol, and methyl ketones give the iodoform test. As acetone has a methyl group adjacent to ketone group, it will give iodoform test.Hence, option D is correct.

Q91. Which of the following is formed when form aldehyde is treated with oxidizing mixture (H2SO4+K2Cr2O7)

• A. Methanol
• B. Methanoic acid✓
• C. Acetone
• D. Acet Aldehyde

Explanation: Aldehydes on oxidation give carboxylic acids. As methanoic acid is carboxylic acid, so, option B is correct.

Q92. Dry distillation of which of the following can be done to produce acetone?

• A. Calcium acetate✓
• B. Calcium formate
• C. Ethyl acetate
• D. Acetic Acid

Explanation: Acetone is prepared by dry distillation of calcium acetate.Hence, option A is correct.

Q93. The elimination reaction between alkyl halides and strong base takes place by two mechanisms, E1 and E2. How many steps are involved in each one of these?

• A. E1 elimination is two steps and E2 is one step✓
• B. E1 and E2 both takes place in one step
• C. E1 and E2 both takes place in two step
• D. E1 elimination is one steps and E2 is two step

Explanation: In E2 elimination, nucleophile attacks and leaving group leaves at the same time with a formation of carbon carbon double bond. So, it is single step reaction. While in E1 elimination, first step is slow ionization of substrate to give carbocation. In second step, nucleophile attacks on hydrogen to give an alkene as a product. So it is two steps reaction. Hence, option A is correct.

Q94. Which of the following is an example of tertiary alkyl halide?

• A. 2-chloro butane
• B. 1-chloto-2- methyl pentane
• C. 2-bromo- 3-methyl butane
• D. 2-bromo-2-methyl butane✓

Explanation: Alkyl halides in which halide group is attached to a carbon atom which is further attached with three other carbon atoms are called tertiary alkyl halides. Hence, 2-bromo-2-methyl butane is tertiary alkyl halide.

Q95. Radius of the first orbit of hydrogen is 0.53 A. Which orbit has a radius of 4.77 A?

• A. First
• B. Second
• C. Third✓
• D. Fourth

Explanation: The radius of any orbit can be calculated by using formula n^2 (0.53) For 1st orbit; (1)^2(0.53) = 0.53Å For 2nd orbit; (2)^2(0.53) = 2.12Å For 3rd orbit; (3)^2(0.53) = 4.77 Å So, 4.77 Å is radius for third orbit. Hence, option C is correct.

Q96. Which of the following has only one orientation is space in the magnetic field?

• A. p orbital
• B. s orbital✓
• C. d orbital
• D. f orbital

Explanation: Orientation of orbitals are given by magnetic quantum number. By using formula; (2l + 1) we can calculate the orientations of orbitals in space. For s orbital, l=0, so; [2(0) +1] = 1, s orbital will have 1 orientation in space. For p orbital, l=1, so; [2(1) +1] = 3, p orbital will have 3 orientations in space. For d orbital, l=2, so; [2(2) +1] = 5, d orbital will have 5 orientations in space. For f orbital, l=3, so; [2(3) +1] = 7, d orbital will have 7 orientations in space.Hence, option B, s orbital is correct.

Q97. What is the mass of one proton?

• A. Equal to 1836 electron✓
• B. Equal to positron
• C. Equal to electron
• D. Equal to 1836 neutron

Explanation: The mass of proton is 1836 times that of electron. STB Pg- 79 Hence, option A is correct.

Q98. Which of the following is different in Na+ (Z=11), Mg+2 (Z=12) and AI+3 (Z=13)?

• A. Number of shells
• B. Number of electrons
• C. Electronic configuration
• D. Number of protons✓

Explanation: The atomic number of Na is 11, so it has 11 electrons and 11 protons . But Na+ has lost 1 electron, so Na+ has 10 electrons and 11 protons. The atomic number of Mg is 12, so it has 12 protons and 12 electrons. But Mg2+ has lost 2 electrons, so Mg2+ has 10 electrons and 12 protons. The atomic number of Al is 13, so it has 13 protons and 13 electrons. But Al3+ has lost 3 electrons, so Al3+ has 10 electrons and 13 protons. So, Na+, Mg2+, Al3+ all have different number of protons. Hence, option D is correct.

Q99. What is the IUPAC name of stearic acid?

• A. Hexanoic acid
• B. Octadecanoic acid✓
• C. Octanoic acid
• D. Hexadecenoic acid

Explanation: Stearic acid is represented by molecular formula C17H35COOH. Since it has 18 carbons (including 1 carbon atom of carboxyl group), it will be written as octadecane and because it is carboxylic acid, hence its IUPAC name will be octadecanoic acid.

Q100. Which of the following is formed when acetone is oxidized?

• A. Formic acid
• B. Ethanoic acid✓
• C. Propanoic Acid
• D. Butyric Acid

Explanation: Ketones on oxidation give carboxylic acids with 1 carbon atom less than ketone. Since acetone contains 3 carbon atoms, it will form a carboxylic acid with 2 carbon atoms which is ethanoic acid or acetic acid.Hence, option B is correct.

Q101. What Is the IUPAC name of α, β-dimethyl valeric acid?

• A. 2,3-dimethyl hexanoic acid
• B. 3,4-dimethyl hexanoic acid
• C. 3,4-dimethyl pentanoic acid
• D. 2,3-dimethyl pentanoic acid✓

Explanation: Valeric acid is the name for pentanoic acid. α carbon is the carbon attached to the carboxyl group. While β carbon is the one attached to α carbon. In IUPAC system, we start numbering the carbon atoms from the carboxyl group so α carbon will be C-2 and β carbon will be C-3. Since one methyl group each is attached to C-2 and C-3, and the parent chain is pentanoic acid, the IUPAC name will be 2,3-dimethyl pentanoic acid.Hence, option D is correct.

Q102. What volume of oxygen at STP required to burn 500 dm3 of ethene?

• A. 500 dm3
• B. 1000 dm3
• C. 1500 dm3✓
• D. 2000 dm3

Explanation: 1 mole of ethene reacts with 3 moles of O2 to burn completely. C2H4 + 3O2 → 2CO2 + 2H2O So, 500dm^3 will react with 1500 dm^3 (500 × 3 =1500) of oxygen. Hence, option C is correct

Q103. Valence shell electronic configuration of an element is 4s2 , 4p1. To which group does the element belong?

• A. Ⅰ-B
• B. Ⅱ-B
• C. Ⅰ-A
• D. Ⅲ-A✓

Explanation: The given valence shell electronic configuration is 4s2, 4p1. The group number is represented by valence electrons. Since valence electrons are (2 + 1 = 3), the group number is 3. Also, its valence subshell is "p", so it belongs to IIIA. As, elements of subgroup A are present in p block of periodic table. Hence, option D is correct.

Q104. Ca (Z=20) forms ionic bond with CI (Z=17)? What is the chemical formula of Calcium Chloride?

• A. CaCI
• B. CaCI2✓
• C. Ca2CI2
• D. Ca2CI

Explanation: The electronic configuration of Ca is 1s2 2s2 2p6 3s2 3p6 4s2 3d10. Since, calcium has 20 electrons, it can lose 2 electrons to attain electronic configuration of argon to attain stability. So it will lose 2 electrons from its outermost subshell i.e., 4s2 Ca → Ca2+ + 2e- The electronic configuration of Cl is 1s2 2s2 2p6 3s2 3p5. Since chlorine is 17 electrons, it can gain 1 electron to to attain electronic configuration of argon to attain stability. So it will gain 1 electron. Cl + 1e- → Cl-. Since, Calcium loses 2 electrons, so 1 electron will be gained by one chlorine atom and other by 2 chlorine atom. So 1 calcium ion will bind with 2 chloride ions. Ca2+ + 2Cl- → CaCl2 Hence, option B is correct.

Q105. CO2 and SO2 are two compounds. Which of the following best describe these two compords?

• A. Both CO2 and SO2 are linear and non polar
• B. CO2 is angular and polar SO2 is linear and non-polar
• C. CO2 in linear and non-polar SO2 is angular and polar✓
• D. Both CO2 and SO2 are angular and polar

Explanation: In CO2, two oxygen atoms are bonded with carbon atom and the geometry will be linear.O=C=OBut, in SO2, although 2 oxygen atoms are bonded with sulphur but due to presence of lone pair on sulphur, the geometry will be angular ( 2 bond pairs and 1 lone pair.)In CO2, both oxygen atoms exert equal and opposite force on carbon atoms, hence cancel out each other's effect. So, CO2 is non - polar.While, in SO2, cancellation does not occur, so SO2 is polar in nature.Hence, option C is correct.

Q106. What hybridization is present on carbon atoms in ethyne C2H2?

• A. sp3
• B. sp2
• C. sp✓
• D. dsp2

Explanation: Ethyne (C2H2) has sp hybridization. This means that each carbon atom in ethyne forms two sigma bonds using one s and one p orbital, resulting in a linear molecular geometry. The two carbon atoms are joined by a triple bond composed of one sigma bond and two pi bonds.

Q107. Which of the following reactions has the same value of Kc and Kp?

• A. N2+ 3H2 ⇌ 2NH3
• B. PCI5 ⇌ PCI3 +CI2
• C. H2 + I2 ⇌ 2HI✓
• D. 2SO2 + O2 ⇌ 2SO

Explanation: The explanation will be added soon!

Q108. Which of the following condition is required for maximum yield of ammonia through Haber's process?

• A. Increasing temperature
• B. Decreasing concentration of reactant
• C. Decreasing pressure
• D. Decreasing temperature✓

Explanation: The reaction between N2 and H2 to give NH3 is exothermic. N2 + 3H2 → 2NH3 ΔH = -92.46KJ/mol. Hence, the yield of ammonia can be increased by decreasing temperature as in exothermic reactions decrease in temperature favors forward reaction i.e, yield of ammonia in this case. The yield of ammonia can also be increased by increasing pressure or removing the product continuously. Hence, option D is correct.

Q109. Which of the Following is true for a reversible reaction at equilibrium?

• A. The rate of forward reaction is greater than backward reaction
• B. The rate of forward reaction is lesser than backward reaction
• C. The rate of backward reaction is equal to forward reaction✓
• D. The rate of backward reaction is greater than forward reaction

Explanation: At equilibrium state, the rate of backward reaction becomes equal to rate of forward reaction. STB Pg- 165. Hence, option C is correct.

Q110. When benzene reacts with isopropyl chloride in the presence of AICI2 as lewis acid, the product formed is isopropyl benzene, what is this reaction called?

• A. Friedel Craft's acylation
• B. Friedel Craft's alkylation✓
• C. Halogenation of benzene
• D. Benzene sulphonic acid

Explanation: The reaction of benzene will alkyl chloride in presence of AlCl3 as Lewis base is known as Friedel-Crafts alkylation.Hence, option B is correct.

Q111. Benzene is subjected to (1) Alkylation (2) Nitration (3) Oxidation, the product is:

• A. m- nitrobenzoic acid
• B. o- nitrobenzoic acid and p- nitrobenzoic acid✓
• C. m-nitrotoluene
• D. o-nitrotoluene and p-nitrotoluene

Explanation: When benzene is subjected to alkylation, the product formed will be alkyl benzene. C6H6 + CH3Cl → C6H5-CH3 + HClThe product formed in this step is toluene.Toluene on nitration will give o-nitrotoluene and p- nitrotoluene which on oxidation will give o-nitrobenzoic acid and p-nitrobenzoic acid.Hence, option B is correct.

Q112. Isopropyl chloride is an example of:

• A. Primary alkyl halide
• B. Secondary alkyl halide✓
• C. Tertiary alkyl halide
• D. Ouaternary alkyl halide

Explanation: Isopropyl chloride is represented as (CH3)2CH-Cl. Since chloride is attached to carbon atom which is further attached to 2 carbon atoms, isopropyl chloride is secondary alkyl halide. Hence, option B is correct.

Q113. Oxidation of Toluene by KMnO4, the product is:

• A. o-nitro toluene
• B. p-nitro toluene
• C. m-nitro toluene
• D. Benzoic acid✓

Explanation: When toluene is subjected to oxidation, only the methyl group undergoes oxidation while the benzene ring remains intact. The methyl group on oxidation given carboxyl group.So, the product will be benzoic acid.Hence, option D is correct.

Q114. What is the IUPAC name of chloroform?

• A. chloro methane
• B. dichloro methane
• C. trichloro methane✓
• D. tetra chloro methane

Explanation: The molecular formula of chloroform is CHCl3. Since, three chloride atoms are attached to carbon atom, so IUPAC name of chloroform will be Trichloro methane. Hence, option C is correct.

Q115. Which of the following produce maleic anhydride on oxidation?

• A. Acetylene
• B. Phenol
• C. Toluene
• D. Benzene✓

Explanation: Beneze is oxidized in presence of vanadium peroxide (V2O5) producing maleic anhydride.STB Pg- 157Hence, option D is correct.

Q116. What is the oxidation number of Mn in K2MnO4?

• A. +2
• B. +4
• C. +6✓
• D. +7

Explanation: The oxidation number of Mn in K2MnO4 can be calculated as follows; 2(K) + Mn + 4(O) = 0 As we know that oxidation nimber of K is +1 and that of O is -2; 2(+1) + Mn +4(-2) =0 +2 + Mn -8 =0 Mn - 6 = 0 Mn = +6. So, the oxidation number of Mn is +6. Hence, option C is correct.

Q117. In electrochemical series, what is the electrode potential of all metals above hydrogen?

• A. zero
• B. Negative✓
• C. Positive
• D. Greater than zero

Explanation: In electrochemical series, the elements present above hydrogen have negative reduction potential while those below hydrogen have positive reduction potential.Hence, option B is correct.

Q118. Organic compounds are classified into:

• A. Both of these
• B. Inorganic compounds and smelly compounds
• C. None of these
• D. Open and chain alicyclic compounds✓

Explanation: Organic compounds are classified into open and chain alicyclic compounds.

Q119. Which of the following are the isomers of pentane?

• A. n-pentane, 2-methyl butane, 2,2-dimethylpropane✓
• B. n-pentane, 2-methyl butane, 2,3-dimethyl butane
• C. n-pentane, 3-methyl butane, 2,2-dimethylpentane
• D. n-pentane, 2-methyl pentane, 2,2-dimethyl propane

Explanation: Pentane has 3 isomers which are as follows; CH3-CH2-CH2-CH2-CH3 (n-pentane) CH3-CH(CH3)-CH2-CH3 (2-methyl butane) CH3-C(CH3)2-CH3 (2,2-Dimethylpropane) Hence, option A is correct.

Q120. Which type of isomerism propanal and acetone exhibit?

• A. functional group isomerism✓
• B. Chain isomerism
• C. Position isomerism
• D. Metamerism

Explanation: Aldehydes and ketones are functional group isomers of each other. Hence, option A is correct.

Q121. Graph of volume versus Pressure at constant temperature:

• A. A straight line
• B. First a curve then a straight line
• C. first a straight line and then a curve line
• D. non linear✓

Explanation: Since, pressure and volume are inversely proportional to each other, the graph between pressure and volume will be curve or non-linear. Hence, option D is correct.

Q122. If a gas has 1 atm pressure is 25°C. What will be the volume change at 2 atm pressure?

• A. 0.542 dm3✓
• B. 2 dm3
• C. 3 dm3
• D. 4 dm3

Explanation: Given that;P1 = 1atmT1 = 25°C = 298KP2 = 2 atm T2=?Change in volume = V2/V1 = ?P1/P2 = T2/T1T2 = P1/P2 × T1 = ½ × 298T2 = 149KV2/V1 = T2/T1 = 149/298 = ½ = 0.5 dm^3Hence, option A is correct.

Q123. Which of the following temperature is referred to as absolute zezo?

• A. -273.16°C✓
• B. -273.16 K
• C. 0°C
• D. 32 °F

Explanation: -273.16°C is referred to as absolute zero. Hence, option A is correct.

Q124. An organic compound has C=40%, H=6.67% and O=53.3% What is the empirical formula of the compound?

• A. CH3O
• B. C2H2O
• C. CH2O✓
• D. C2H6O

Explanation: Emprical formula can be calculated as follows; Number of atoms of C = 40/12 =3.33 Number of atoms of H = 6.68/1 = 6.67 Number of atoms of O = 53.3/16 =3.33 Taking ratio; C:H:O 3.33:6.67:3.33 1:2:1 Thus, Emprical forumla will be CH2O. Hence, option C is correct.

Q125. 7.6 grams of CS2 is reacted with 12.8 g of O2, CS2, + 3O2, —> CO2 + 2SO2 limiting reactant ts:

• A. CS2✓
• B. O2
• C. CO2
• D. SO2

Explanation: The balanced chemical equation is; CS2 + 3O2 → CO2 + 2SO2 Since molecular mass of CS2 is 12+ 64 =76g/mol The given mass is 7.6g, Hence number of moles of CS2 = 7.6/76 = 0.10 moles The molecular mass of O2 is 32g/mol The given mass of O2 is 12.8g Hence number of moles of O2 = 12.8/32 =0.13 Since CS2 is taken in less amount, it is limiting reactant. Hence, option A is correct.

Q126. Water rises In capillary tube because of:

• A. Cohesive force and adhesive force are same
• B. Adhesive forces of molecules exceed cohesive force✓
• C. Cohesive force is greater than adhesive force
• D. Cohesive and adhesive force to explain the property in the above question is irrelevant

Explanation: The capillary action arises when the adhesive force of liquid is greater than the cohesive force between liquids and it will lead to a rise of liquid in the capillary tube. Hence, option B is correct.

Q127. Which of the following influences the variation of temperature at which boiling of liquid takes place?

• A. Outside pressure✓
• B. Outside temperature
• C. Volume of container
• D. Amount of liquid

Explanation: The temperature of boiling point is influenced by atmospheric pressure also knowm as external pressure or outside pressure. Hence, option A is correct.

Q128. Enzyme show optimum activity between 37°C to 50°C It however loses activity permanently above

• A. Above 40°C
• B. Below 37°C
• C. it loses activity permanently above 50°C✓
• D. It loses activity permenantly below 37°C

Explanation: Exam Prep/eq/Sindh%20MDCAT 2023/65008a6927a806235f157a01?reportid=65577581cd7bef1eced55468If the optimum temperature for an enzyme is 37°C to 50°C, it means that increasing temperature above 50°C, will denature the enzyme and it will lose its activity permanently. Hence, option C is correct.

Q129. Oxidation of secondary propyl alcohol gives:

• A. Aceton✓
• B. Acet aldehyde
• C. Ethyl alcohol
• D. n-propyl alcohol

Explanation: The oxidation of secondary alcohol gives ketones. Hence oxidation of secondary propyl alcohol (containing 3 carbon atoms) will give acetone (containing 3 carbon atoms). The oxidation of secondary alcohol gives ketones. Hence oxidation of secondary propyl alcohol (containing 3 carbon atoms) will give acetone (containing 3 carbon atoms).Hence, option A is correct.

Q130. Which of the following is an amino acid?

• A. Benzoic acid
• B. Palmitic acid
• C. Aspartic Acid✓
• D. Aniline

Explanation: Benzoic acid (C6H5COOH) and palmitic acid (C15H31COOH) are carboxylic acids, while aniline (C6H5NH2) is aromatic hydrocarbon. However, aspartic acid is an amino acid.Hence, option C is correct.

Q131. What is the order of reaction, if the unit of K is sec-1 ?

• A. One✓
• B. Two
• C. Three
• D. Zero

Explanation: The units of Kc are as follows; For Zero order reaction → moldm^-3sec^-1 For 1st order reaction → sec^-1 For 2nd order reaction → dm^3mol^-1sec^-1 For 3rd order reaction → mol^-2dm^-6sec^-1 Hence, sec^-1 is unit for 1st order reaction. So, option A is correct.

Q132. Which of the following best describes the ionic reaction of inorganic compounds?

• A. Very slow
• B. Moderately slow
• C. Very fast✓
• D. Not occurs

Explanation: The ionic reactions of inorganic compounds are very fast because these reactions involve combination of opposite ions without involving rearrangment of electronic cloud. Hemce, option C is correct.

Q133. Metallic property in a group of P-block element has a trend:

• A. Decreases
• B. Increases✓
• C. Remains same
• D. Irregular trend

Explanation: Metallic property is ability of an atom to lose electrons to form positive ions.Metallic property in of p-block elements decreases because size of atom decreases and the removal of electron from outermost shell becomes difficult. Hence, option B is correct.

Q134. Superoxide of Group I-A element (M) has formula:

• A. M2O
• B. M2O4
• C. MO2✓
• D. M2O2

Explanation: The oxidation state of superoxide is O2^-½. Hence, the molecular formula will be MO2, where M is M^+1 and O is O^-½. For example, potassium superoxide (KO2.)

Q135. Which pair of elements markedly differ from other members of their respective groups?

• A. Potassium and Calcium
• B. Sodium and Magnesium
• C. Cesium and Barium
• D. Lithium and Beryllium✓

Explanation: Because of small size and high charge density, the first member of every group differs from the rest of members of same group. In the given options, lithium and beryllium differs from other members of group IA and IIA respectively. Hence, option D is correct.

Q136. Which of the following is a covalent crystal?

• A. NaCI
• B. KCI
• C. MgBr
• D. Diamond✓

Explanation: The covalent crystal is also known as atomic crystals because it is between same atoms. NaCl, KCl and MgBr are ionic crystals. Whereas diamond ( C ) is covalent crystal. Hence, option D is correct.

Q137. The nature of attraction which hold molecular crystals is:

• A. ionic bond
• B. hydrogen bond
• C. Covalent bond
• D. Van der Waal forces✓

Explanation: Molecular forces have both hydrogen bonding and Van der Waal forces between them. Since, hydrogen bonding also comes under Van der Waal forces, option D will be most suitable answer.

Q138. What is the mathematical statement of the first law of thermodynamics?

• A. ∆E=q+W
• B. ∆E=-q+W
• C. ∆E=-q-W
• D. ∆E=q-W✓

Explanation: The expression for 1st law of thermodynamics is ΔE = q-w STB Pg- 157

Q139. What Is ∆H equal to according to the first law of thermodynamics?

• A. ∆E - P∆V
• B. ∆E + P∆V✓
• C. -∆E + P∆V
• D. -∆E - P∆V

Explanation: ΔH is known as change in enthalpy which is the sum of internal energy and work done. Hence, ΔH = ΔE + PΔVSo, option B is correct.

Q140. Why do transition elements form interstitial compounds?

• A. Presence of unpaired electrons
• B. Transition of electrons from t2g to eg within d orbitals
• C. Holes present in crystal lattice of transition elements✓
• D. Small, highly charged ions and vacant d-orbitals of suitable energy

Explanation: Transition elements form interstitial compounds bevause they have holes in their crystal lattice in which small atoms like C,N,B and H can reside. So, option C is correct.

Q141. The ligand, diethylene triamine is an example of:

• A. Bidentate
• B. Tridentate✓
• C. Pentadentate
• D. Hexadentate

Explanation: Since diethylene triamine has three amine groups, having one lone pair on each amine group, it has total of 3 lone pairs. So, it will donate 3 lone pairs to metal. Therefore, it is tridentate ligand. Tridentate ligand is the one which donates three lone pairs to metal atom.

Q142. In which spectral series is the far ultraviolet region of electromagnetic spectrum found?

• A. Paschen series
• B. Balmer series
• C. Lyman series✓
• D. Pfund series

Explanation: The explanation will be added soon!

Q143. The ohm's law is applicable if:

• A. Temperature of the conductor becomes infinite
• B. Temperature of the conductor increases
• C. Temperature of the conductor decreases
• D. Temperature of the conductor remains same✓

Explanation: "The current flowing through a conductor is directly proportional to potential difference across its ends provided the physical state such as temperature etc. remains constant." Hence, option D is correct.

Q144. Which of the following refers to the DC current that does not change its intensity?

• A. Eddy's current
• B. Surge current
• C. Leakage current
• D. Steady current✓

Explanation: The DC current which does not change its intensity is known as steady current. Hence option D is correct.

Q145. The internal resistance of a battery is:

• A. In parallel to the external load
• B. In series to the external load✓
• C. Not connected to the external load
• D. Zero

Explanation: The internal resistance of a battery is in series to external load. Hence option B is correct.

Q146. The electric potential sets across the terminals of a battery is called:

• A. Potential difference
• B. EMF
• C. Internal potential energy
• D. Terminal voltage✓

Explanation: The electric potential set across the terminals of a battery is known as terminal potential difference or terminal voltage. Hence, option D is correct.

Q147. 1 J/sec is equals to:

• A. 1 K
• B. 1 N
• C. 1 T
• D. 1 Watt✓

Explanation: 1 J/sec = W/s/sec = watt. It can also be solved as, Joule/sec = work done/ time = power The SI unit of power is watt.

Q148. Which of the following corresponds to the momentum of a photon?

• A. hλ
• B. h/λ✓
• C. λ/h
• D. h2/λ2

Explanation: E = pc hc/λ = pc p = h/λ Hence, option B is correct.

Q149. If the wavelength of a light is 3×10-7, then what is it its frequency?

• A. 1×1013 Hz
• B. 1×1014 Hz
• C. 1×1015 Hz✓
• D. 1×1016 Hz

Explanation: By using c = f λ f = c/λ = 3 ×10^8/3 × 10^-7 f = 1 × 10^8+7 f = 1 × 10^15 Hz Hence, option c is correct.

Q150. The energy of light is determined by its:

• A. Frequency✓
• B. Intensity
• C. Amplitude
• D. Speed

Explanation: As E = hf Where, h is constant. Energy is determined by frequency. Hence, option A is correct.

Q151. On which principle does the transformer work?

• A. Self induction
• B. Mutual induction✓
• C. Motional EMF
• D. Magnetic torque

Explanation: Transformer works on the principal of mutual induction, according to which; "The phenomenon in which a changing current in one coil induces an emf in anofher coil is called the mutual inductance." Hence, option B is correct.

Q152. If 1 transformer has 500 turn on primary coil and 250 turns on secondary coil, then:

• A. Output voltage is half of input voltage✓
• B. Output and input voltages are equal
• C. Output voltage is double of input voltage
• D. Output voltage is zero

Explanation: Using formula; Np/Ns = Vp/ Vs 500/250 = Vp/Vs 2 = Vp/Vs So Vp = 2Vs or Vs = Vp/2 Hence, secondary voltage or output voltage is half of input or primary voltage. So, option A is correct.

Q153. Which of the following defines the change in magnetic flux unit area?

• A. Magnetic field
• B. Magnetic force
• C. Magnetic dipole
• D. Magnetic flux density✓

Explanation: Change in magnetic flux per unit area is Φ/A which is equal to B i.e. magnetic flux density. Φ = B . A Hence, option D is correct.

Q154. What is the dot product of magnetic induction and unit area?

• A. Magnetic flux✓
• B. Magnetic induction
• C. Magnetic field
• D. Magnetic pole

Explanation: Magnetic induction per unit Area is B/A which is equal to Φ i.e., magnetic flux Φ = B . A Hence, option A is correct.

Q155. What does the magnetic flux measure?

• A. Area surrounded by a magnet
• B. Strength of the magnetic field
• C. Rate of change of magnetic force
• D. The number of magnetic lines of force✓

Explanation: Magnetic flux is number of magnetic field lines passing through a surface placed perpendicular to it. Hence, option D is correct.

Q156. The change in electric potential with respect to distance equals to:

• A. Potential gradient✓
• B. Amount of the charge
• C. Potential difference
• D. Surface charge density

Explanation: The change in electric potential with respect to distance is ΔV/Δr which represent s potential gradient. Hence, option A is correct.

Q157. The amount of energy required in moving an electron of charge (e) by the application of 1 volt potential difference equal to:

• A. 1 keV
• B. 1 MeV
• C. 1 GeV
• D. 1 eV✓

Explanation: The amount of energy required in moving an electron of charge by application of 1V potential difference equals to 1 eV. STB Pg-64 Hence, option D is correct.

Q158. Which law explains the relation between amount of charges and force between them?

• A. Ohm's law
• B. Lenz's law
• C. Coulomb's law✓
• D. Ampere's law

Explanation: Coulomb's law represents the relation between amount of charges and force between them. STB Pg-40 Hence, option C is correct.

Q159. What does the electric field around a charge represent?

• A. Size of the charge
• B. Effective area for electrostatic force✓
• C. Path followed by the charge
• D. Speed of the charge

Explanation: The electric field lines represent the area around charge where the electrostatics force of charge can be experienced by other charges. STB Pg-45. Hence, option B is correct.

Q160. 1 N/C equals to:

• A. 1 V/m✓
• B. 1 J/C
• C. 1 C/m2
• D. 1 1/sec

Explanation: V/m = J/C/m = N × m/ m× C = N/C. Hence, Option A is correct.

Q161. What will be the value of acceleration, if a body of mass 0.5 kg is acted upon by force of 10 N?

• A. 40 m/s2
• B. 5 m/s2
• C. 10 m/s2
• D. 20 m/s2✓

Explanation: As m =0.5kg F = 10N Using; F = ma a = F/m a = 10/0.5 a = 20ms^-2. Hence, option D is correct.

Q162. What is the time rate of change of linear momentum?

• A. Acceleration
• B. Force✓
• C. Velocity
• D. Work

Explanation: The time rate of change of momentum is represented as Δp/Δt which is equal to force 'F'. Hence, option B is correct.

Q163. Radiations are dangerous to living organism because they damage the cell by:

• A. By producing ions in the cells✓
• B. By increasing the temperature of cells
• C. By decreasing the number of cells
• D. By destroying the cells

Explanation: Radiations are damaging to living organisms because cause ionisation of living cells. STB Pg-341 Hence, option A is correct.

Q164. Which of the following results in the centripetal acceleration is produced in a body?

• A. Change in magnitude of velocity
• B. change in mass
• C. Change in magnitude of force
• D. Change in direction of velocity✓

Explanation: When a body travels on a circular path, its direction constantly changes and thus its velocity changes, producing an acceleration. Hence option D is correct.

Q165. 1 radian is equals to:

• A. 0.573°
• B. 5.73°
• C. 57.3°✓
• D. 573°

Explanation: 1 rad = 57.3° STB Pg- 115

Q166. A wheel of bike rotates from rest and achieves 6.28 radian/sec in 2 seconds. What will be its angular acceleration?

• A. 1 rad/sec2
• B. 1.5 rad/sec2
• C. 3.14 rad/sec2✓
• D. 6.28 rad/sec2

Explanation: As w = 6.28 rad/sec t = 2 sec α = w/t = 6.28/2 α = 3.14 rad/sec^2 Hence, option C is correct.

Q167. The ratio between linear velocity and radius equals to:

• A. Angular displacement
• B. Angular velocity✓
• C. Angular acceleration
• D. Angular momentum

Explanation: As v = r × w v/r = w Hence, the relation between linear velocity and radius is equal to angular velocity.

Q168. Which law has a graph similar to the graph of isothermal process?

• A. Boyle's law✓
• B. Charle's law
• C. Avogadro's law
• D. Law of heat exchange

Explanation: Boyle's law gives the relation between pressure and volume at constant temperature (isotherm). Hence, the graph of Boyle's law is similar to that of isothermal process. The graph of Charles law is similar to graph of isobaric process. Hence, option A is correct.

Q169. Due to sudden rain, which of the following is true for the car moving on the road?

• A. Force of engine decreases
• B. Balance will not be maintained✓
• C. Direction of motion will not be effected
• D. Linear momentum increases

Explanation: Rain can make the road surface slippery, reducing traction between the tires and the road. This can lead to a loss of control or skidding, potentially causing the car to change direction unexpectedly. Hence, option B is correct.

Q170. Which of the following are the application of Doppler's effect?

• A. Hologram technology
• B. To obtain the frequency of the matter waves
• C. Determining speed of light in mediums
• D. Sending radar signals✓

Explanation: The applications of doppler effects are tracking satellite, measuring speed of automobile by traffic police, sending radar signals, VOR, homosonde, sonar and spectral analysis of light emitted by stars.

Q171. Longitudinal waves exhibit:

• A. Polarization
• B. Particle nature
• C. Property of energy transmission in space
• D. Phenomena of superposition of waves✓

Explanation: In air column and wind instruments, longitudinal waves produce superposition. Hence, option D is correct.

Q172. The property of the system that does not change during adiabatic change is:

• A. Temperature
• B. Volume
• C. Pressure
• D. Amount of heat✓

Explanation: In adiabatic process, heat remains constant. Q =constant ΔQ = O Hence, option D is correct.

Q173. Which statement is the best for electric flux of a point charge?

• A. Independent of charge
• B. Independent of medium
• C. Independent of shape of surface in which charge is enclosed✓
• D. Independent position of charge in shape

Explanation: Electric flux is given as; Φ =Q/ε0 So, electric flux depends upon medium and charged enclosed. It is independent of shape of surface in which charge is enclosed.

Q174. In beta positive decay, the nuclear number is:

• A. Conserved✓
• B. Not conserved
• C. Unstable
• D. Stable

Explanation: In beta positive decay, the number of electron is increased by one, but the number of nucleons i.e., neutrons and protons remain constant. Hence, option A is correct.

Q175. Which of the following expression is constant for a freely falling body?

• A. mgh+ mv2
• B. mgh - mv2
• C. mgh + ½ mv2✓
• D. mgh - 1/2mv2

Explanation: When a body falls freely, its kinetic energy increases while its potential energy decreases. But the total mechanical energy is conserved during the free fall. Hence E = P.E + K.E is constant. E = mgh + ½ mv^2 Hence, option C is correct.

Q176. The product of frequency and wavelength of a wave equals to:

• A. Displacement of the wave
• B. Amplitude of the wave
• C. Speed of the wave✓
• D. Time period of the wave

Explanation: As v= fλ So the product of frequency and wavelength is equal to speed of wave.

Q177. Two bodies of masses 10 kg and 40 kg are dropped from the same height at the same time. Value of which of the following remains the same during the motion of the two bodies?

• A. Acceleration✓
• B. kinetic energy
• C. Potential energy
• D. Power

Explanation: Since both bodies move under gravitational acceleration, that is the same throughout the movement and same for both bodies, therefore, option A is correct.

Q178. A body of mass 4 kg is moving a circle of radius 2m. If the body moves round a complete circle, what is the work done by the body?

• A. 8J
• B. Zero✓
• C. 16J
• D. 6J

Explanation: Work done in a closed path is zero, since complete circle is a closed path, therefore, correct option is B i.e., zero.

Q179. 1 kilowatt-hour (kWh) equals to:

• A. 3.6 J
• B. 3.6 kJ
• C. 3.6 MJ✓
• D. 3.6 GJ

Explanation: 1kWh = 3.6MJ STB Pg- 201

Q180. In standing waves, the distance between two consecutive nodes or anti- nodes is:

• A. 2λ
• B. λ/2✓
• C. λ/4
• D. λ

Explanation: In standing waves distance between two consecutive nodes or antinodes is λ/2. STB Pg- 247

Q181. If the fundamental frequency of vibration of a string fixed both ends is 50Hz, the fourth harmonic will be:

• A. 200Hz✓
• B. 150Hz
• C. 12.5Hz
• D. 250Hz

Explanation: Since in case of string fixed at both ends harmonics are integral multiple of fundamental frequency, fn =n(f) So, for fourth harmonic, f4 = 4(50) f4 = 200Hz Hence, option A is correct.

Q182. A ball is thrown horizontally with 19.6 m/s. After 2 seconds it's horizontal velocity component will be:

• A. 4.9 m/s
• B. 9.8 m/s
• C. 19.6 m/s✓
• D. 39.2 m/s

Explanation: In projectile motion, horizontal component of velocity remains constant, so horizontal velocity after 2 sec will remain 19.6m/sec. So, correct option is C.

Q183. In the projectile motion, the acceleration in the horizontal direction:

• A. Remains same
• B. Varies with time
• C. Is zero✓
• D. Is positive

Explanation: Since horizontal component of velocity remains constant in projectile motion, therefore, the acceleration in horizontal direction is zero. Hence, option C is correct.

Q184. In vibratory motion the maximum displacement of the body on either side of its equilibrium position is called:

• A. Distance
• B. Displacement
• C. Amplitude✓
• D. Frequency

Explanation: In vibratory motion, maximum displacement of body on either side of its equilibrium position is known as amplitude. Hence, correct option is C.

Q185. The process in which no external work is performed is called:

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

Explanation: In isochoric process, volume remains constant. As, W = PΔV V =constant ΔV = O So, W =O. Thus, is isochoric process, no external work is done. Hence, option B is correct.

Q186. Induced FMF in A.C. generator can be increased by:

• A. Decreasing area of coil
• B. Decreasing magnetic field
• C. Increasing area of coil✓
• D. Slowing down speed of coil

Explanation: As, ε = BΔA/Δt Thus, induced emf can be increased by increasing area of coil. Hence, option C is correct.

Q187. A semi-conductor diode can be used as:

• A. A full wave rectifier
• B. An amplifier
• C. A transmitter
• D. A half wave rectifier✓

Explanation: A semiconductor diode, also known as crystal diode, can be used as a diode. STB Pg- 203

Q188. Half-life of radon gas is:

• A. 3.8 minutes
• B. 3.8 days✓
• C. 3.8 months
• D. 38 years

Explanation: Half life of radon gas is 3.8 days. Hence, option B is correct.

Q189. Two capacitors 6μf and 12μf are in series connected across a 200 volts D.C. supply, Calculate the charges on each capacitor, respectively.

• A. 8x10-4 C, 8x10-4 C✓
• B. 8μC, 8μC
• C. 8×104C, 16×104C
• D. 800C, 800C

Explanation: As C1= 6µF C2 = 12µF V = 200V Ceq = 6(12)/18 = 4µF Q = CV = 4 ×10^-6 × 200 = 8 × 10^-4C In series, charge remains same, so same charge will flow through both capacitors. Hence, option A is correct.

Q190. Soft cylindrical electrical conducting wire has resistance R. It is streat so that its length is doubled but its radius stays constant. What would be the new resistance?

• A. R/2
• B. R
• C. 4R
• D. 2R✓

Explanation: As R = ρL/A R ∝ L If length is doubled then R is also doubled, so R =2R. Hence, option D is correct

Q191. The speed of sound at 0°C in air is 332 m/s What will be the speed of sound at 50°C?

• A. 300 m/s
• B. 332 m/s
• C. 362 m/s✓
• D. 382 m/s

Explanation: As vt = vo + 0.61(t°C) vt = 332 + 0.61(50) vt = 362 m/s Hence, option C is correct.

Q192. A force 2F acting on a particle of mass 10 kg produces an acceleration of 30 m/s2. A force 5F acting on a particle of mass M produces and acceleration are 25 m/s2. What is the mass M?

• A. 30 kg✓
• B. 21 kg
• C. 4.8 kg
• D. 3.3 kg

Explanation: Given that; F1 = 2F m1 = 10kg a1= 30m/s^2 F2 = 5F m2 =M a2 = 25 m/s^2 F1 = m1a1 2F = 10 × 30 F = 300/2 F = 150 F2 = m2a2 5(150) = M × 25 750/25 = M M = 30kg. Hence, option A is correct.

Q193. The main function of a transformer is to convert:

• A. One direct voltage to another direct voltage of different magnitude
• B. One alternating voltage to another alternating voltage of different magnitude✓
• C. High value alternating voltage to a low value direct voltage
• D. A low value alternating voltage to a high value direct voltage

Explanation: A transformer is a device that steps up or steps down alternating current or voltage. STB Pg- 146. Hence, option B is correct.

Q194. An atom makes a transition from a state of energy E2 to one of lower energy E1. Which of the following gives the wavelength of the radiation emitted, in terms of the Planck's constant h and the speed of light e?

• A. E2-E1/hc
• B. hc/E2-he/E1
• C. hc/E2-E1✓
• D. c/h(E2-E1)

Explanation: By quantum theory of radiation, the energy change E between energy levels is proportional to the frequency of electromagnetic radiation f and is given by the quantion below E =hf =hc/λ where h is the Planck's constant, c is the speed of light and λ is the wavelength of the radiation. Now, energy change by transition from E2 to E1 is given by E = E2 – E1 E2 – E1 = hc/λ λ = hc/ E2 – E1 Hence, option c is correct.

Q195. Essa Is younger than Moosa.X=Twice Essa's ageY=Moosa's ageWhich of the following is true about this information?

• A. X >Y
• B. Y > X
• C. X = Y
• D. The relationship cannot be determined✓

Explanation: The relationship cannot be determined because no relation between X and Moosa is given. Hence, option D is correct.

Q196. Look carefully at the symbols to find the pattern. Select the pattern from the options given below:

• A. A
• B. B
• C. C
• D. D✓

Explanation: In the given patterns, the upper curve is converting into a semicircle from left to right and the below curve is also converting into a semicircle starting from 3 box. So the next pattern should have 2 complete semicircles. Hence, option D is correct.

Q197. Sara is five ranks below the top student Faiq in a class of 50 students. What is Sara's rank from the bottom of the class?

• A. 5th
• B. 15th
• C. 45th✓
• D. 55th

Explanation: Since Sara is on 5th rank of class of 50 students. By subtracting 5 from 50, Sara should be on 45th rank from bottom of class. Hence, option C is correct.

Q198. if blue is called green', green is called 'white', white is called 'red',and red is called 'yellow', what is the color of milk?

• A. White
• B. Green
• C. Yellow
• D. Red✓

Explanation: Since, milk is white in colour and according to given statement, white is called red; therefore, color of milk is red. Hence, option D is correct.

Q199. Read the statement and following courses of action carefully. Then select the most appropriateoptions.Statement English language skills of students in XYZ school are below the town average.Course of Action:ⅰAll English language teachers in XYZ school, should be replaced with good ones.ⅱEnglish language teachers in XYZ school, should be provided a training course

• A. The most appropriate approach is (i)
• B. The most appropriate approach is (ii)✓
• C. Both (i) and )ii) are appropriate approaches
• D. None of (i) or (ii) is an appropriate approach

Explanation: Statement (ii) i.e., All English language teachers in XYZ school, should be provided a training course is most appropriate approach. Hence, option B is correct.

Q200. Read the two statements carefully then choose the best from the options to follow:Statement 1- It was raining cats and dogs.Statement 2-The football match was cancelled

• 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.
• D. Both the statements (i) and (ii) are effects of independent causes.

Explanation: Since it was raining cats and dogs; therefore, the football match was canceled. Hence, statement (i) is cause and statement (ii) is effect. Therefore, option A is correct.