Sindh Mcat Nts 2013 Lumhs — Solved Past Paper with Answers

Q1. Older people often affirm that the modern world is suffering from too much entertainment, or at least from too much ready-made entertainment. Instead of doing things for ourselves, the tendency nowadays is to sit and listen to, or watch, a few artists and athletes doing things for us. The gramophone, the radio, the cinema and the television are recent inventions which have entirely changed the pattern of entertainment in the modern world. Modern means of travel, too, have made it possible for large numbers of people to assemble in one place at one time to watch open-air sporting events. Is this altogether a good thing? In the old days people had to provide their own amusements.According to the author the pattern of entertainment changed because of: Old people’s views about modern entertainmentNovel interventionsPeople becoming lazyModern means of travel

• A. 1 only
• B. 2 only
• C. 1 & 2 Only
• D. 2 & 4 Only✓
• E. 1, 2, 3 & 4

Explanation: It can be inferred from Lines 4 and 5 that modern means of travel and novel interventions like gramophone, radio, cinema and the television changed the views about modern entertainment

Q2. Older people often affirm that the modern world is suffering from too much entertainment, or at least from too much ready-made entertainment. Instead of doing things for ourselves, the tendency nowadays is to sit and listen to, or watch, a few artists and athletes doing things for us. The gramophone, the radio, the cinema and the television are recent inventions which have entirely changed the pattern of entertainment in the modern world. Modern means of travel, too, have made it possible for large numbers of people to assemble in one place at one time to watch open-air sporting events. Is this altogether a good thing? In the old days people had to provide their own amusements It can be inferred from the passage that old people are:

• A. Happy with the new pattern of entertainment
• B. Annoyed with the new pattern of entertainment✓
• C. Not interested in the new pattern of entertainment
• D. Very much fond of the new pattern of entertainment
• E. The passage does not show the aptitude of old people

Explanation: It can be directly inferred from Line 1 of the passage that older people say that the world is “suffering” from too much(new pattern) of entertainment. The word suffering explains that older people tend to take this new pattern entertainment as annoyance,Complete the sentences by choosing the most appropriate option, from the given lettered choices (A to E) below each.

Q3. New _ have brought to pass amazingly rapid changes in our means of communications.

• A. Fictions
• B. Designs
• C. Inventions✓
• D. Accidents
• E. Climates

Explanation: New inventions have actually brought rapid changes in our means of communications like mobile phones, telephone, email etc.

Q4. I like our professor’s lectures because he _ the really important points clearly.

• A. Brings out✓
• B. Brings off
• C. Brings over
• D. Brings of
• E. Brings at

Explanation: The correct phrase to use in the sentence above will be “brings out” as it makes the most sense

Q5. Identify the word or phrase that needs to be changed for the sentence to be correct: You can’t fight a dual nowadays; you are behind the times. No error.

• A. Can't
• B. Dual✓
• C. Are
• D. The times

Explanation: You don’t fight a “dual” but a fight a “duel”

Q6. Identify the word or phrase that needs to be changed for the sentence to be correct: I am to busy to take you to the theatre this evening. No error

• A. To✓
• B. To take
• C. To the theatre
• D. No error

Explanation: The correct preposition to use here will be “too” rather than “to”. “Too” implies intensity which is required in this sentence.

Q7. Choose the lettered word or phrase that is most nearly opposite in meaning to the following word:BRIGHT

• A. Dark✓
• B. Quick
• C. Mobile
• D. Open
• E. Light

Explanation: Bright means something vibrant, full of light.The opposite of which will be dark!

Q8. Choose the lettered word or phrase that is most nearly opposite in meaning to the following word:ENORMOUS

• A. Massive
• B. Deep
• C. Release
• D. Tiny✓
• E. Bulky

Explanation: Enormous refers to something very big.The opposite of which will be something very small, the word for which is “tiny”

Q9. Choose the word most similar in meaning to the following word:.PORTER

• A. Supervisor
• B. Luggage
• C. Carrier✓
• D. Teacher
• E. Loyal

Explanation: PORTER means “a person employed to carry luggage and other loads, especially in a railway station, airport, hotel, or market”. This is quite similar to what is meant by the word carrier.

Q10. Choose the word most similar in meaning to the following word:CRUEL

• A. Kind
• B. Shameless
• C. Caring
• D. Inhuman✓
• E. Thoughtful

Explanation: Cruel means someone who is very aggressive and dangerous. The closest word to which will be inhuman

Q11. A species of rose plants can be purchased as red, white, or pink flowering plants. Assuming that large petals is a dominant trait, which is the genotype of a plant with pink flowers and large petals? [ W = white flowers, w = red flowers, L = large petals, I = small petals]

• A. WwLL✓
• B. WWLL
• C. WWLl
• D. wwLL
• E. wwII

Explanation: The correct genotype for a plant with pink flowers and large petals is WwLL. A plant with pink flowers must have one allele for white flowers (W) and one for red flowers (w), resulting in the heterozygous combination Ww. This combination produces pink flowers due to incomplete dominance. The plant also has large petals, which is a dominant trait, so it must have at least one dominant allele for large petals (L). In this case, the plant is homozygous dominant (LL) for large petals, ensuring the large petal trait is expressed. Other options either lead to incorrect flower colors or petal sizes based on their genotypes.

Q12. Common to the Krebs cycle and glycolysis in eukaryotes is:

• A. Production of FADH2
• B. Localization in mitochondria
• C. Occurrence in anaerobic conditions
• D. Substrate-level phosphorylation✓
• E. Oxygen utilization

Explanation: Glycolysis and Kreb’s Cycle both produce ATP by substrate-level phosphorylation.FADH2 is not produced in glycolysis but only in Krebs Cycle.Krebs Cycle is only localised to mitochondria.Moreover, glycolysis occurs in anaerobic and aerobic respiration; however,krebs cycle occurs in aerobic respiration.Oxygen utilization occurs only in Krebs cycle,glycolysis can occur without oxygen.

Q13. Which of the following is mismatched?

• A. Nervous system … reception, conduction, integration, effect
• B. Skeletal system … posture, protection, locomotion, blood cell production
• C. Epidermis … support, integration, exchange, filtration✓
• D. Gastrointestinal system … absorption, secretion, digestion, egestion

Explanation: This is incorrect (mismatched) because the epidermis primarily functions in protection, preventing water loss and acting as a barrier against pathogens. It does not play a role in integration or filtration, and its role in exchange is limited.

Q14. Class of annelida whose members are exclusively marine?

• A. Polychaeta✓
• B. Oligochaeta
• C. Hirudinea
• D. None of these

Explanation: The class Polychaeta is exclusively marine, with members adapted to life in marine environments through specialized structures like parapodia. Oligochaeta and Hirudinea are not exclusively marine, with Oligochaeta found mostly in soil or freshwater and Hirudinea in freshwater or moist terrestrial environments.

Q15. Select the correct statement:

• A. The ankle has seven tarsals.✓
• B. The wrist contains nine small carpal bones.
• C. The fibula is the bone of the thigh.
• D. Four metatarsals are present in the sole.

Explanation: There are seven tarsal bones in the foot.All other options are wrong because the wrist has eight carpal bones, fibula is a bone of leg not thigh and in sole we have four metatarsals each for each toe.

Q16. Pheretima posthuma is the biological name for _.

• A. Sea anemone
• B. Corals
• C. Obelia
• D. Jellyfish
• E. Earthworm✓

Explanation: Pheretima posthuma is the scientific name of earthworm.

Q17. It is an example of palindromic sequence:

• A. AGTC
• B. ATGGTA✓
• C. GCATGC
• D. AATTGC

Explanation: A palindromic DNA sequence is a sequence of base pairs that reads the same in the 5′ → 3′ direction on both strands.Top strand: 5′–GCATGC–3′ Complementary strand: 3′–CGTACG–5′ → read 5′→3′ → 5′–GCATGC–3′ 🔹 Same sequence, so palindromic ✅

Q18. Which is the correct sequence of passageways through which air travels during inhalation?

• A. Pharynx -> Trachea -> Bronchioles -> Bronchi -> Alveoli
• B. Pharynx -> Trachea -> Lungs -> Bronchi -> Alveoli
• C. Larynx -> Pharynx -> Trachea -> Bronchi -> Alveoli
• D. Pharynx -> Larynx -> Trachea -> Bronchi -> Alveoli✓

Explanation: The air is taken in the respiratory system via the nostrils in the nasal chamber. The air moves across the different parts of pharynx namely nasopharynx, oropharynx and laryngopharynx, from where it is directed to the larynx. The larynx is placed over the trachea, so air then moves to the trachea or windpipe. From the trachea, it travels through the bronchi, bronchioles and ultimately reaches the alveoli for exchange with blood.Hence, the correct answer is Pharynx → Larynx → Trachea → Alveoli

Q19. Which of the following associations between the hormone and its role is FALSE?

• A. Estrogen - development of secondary sexual characteristics
• B. Progesterone - development and maintenance of endometrial walls
• C. LH - stimulate ovulation
• D. FSH - formation of the ovarian follicles into the corpus luteum✓

Explanation: FSH has its role in stimulating the development of primary follicles NOT in formation of corpus luteum. Corpus Luteum is actually formed as a result of LH hormone that causes the rupture to release oocyte.

Q20. According to normal genetic prediction a color blind girl (Xc Xc) must have had a father whose genetic makeup was:

• A. Xc Xc
• B. Xn Yc
• C. Xc Yc
• D. XY
• E. Xc Y✓

Explanation: A color blind female must have a father with XcY because color blindness is a sex-linked trait - recessive in nature,so father must have this trait to get give it to their daughter to make it appear in her phenotype because the only way a female can be colour blind is by having BOTH of color blind alleles.

Q21. The diagram shows a process involving DNA. What is the name of the process and the stage in the cell cycle at which it occurs?

• A. PROCESS STAGEReplication Interphase✓
• B. PROCESS STAGEReplication Prophase
• C. PROCESS STAGETranscription Interphase
• D. PROCESS STAGETranscription Prophase
• E. PROCESS STAGEReplication Telophase

Explanation: It is a replication of DNA in which one DNA molecule divides to form two DNA molecules, this replication occurs during S-phase of the cell cycle which occurs during the interphase.

Q22. What occurs when sucrose is broken down to monosaccharides?

• A. Reducing sugars and releasing water
• B. Condensation of reducing sugars using water
• C. Hydrolysis, releasing reducing sugars and releasing water
• D. Hydrolysis, releasing reducing sugars and using water✓

Explanation: Sucrose gets broken down to release monosaccharides this process is called hydrolysis which occurs when water is added and causes the release of reducing sugars in the solution

Q23. Some chemicals, used to stop tumour growth, work by preventing the DNA double helix from uncoiling and separating. During which stage of the cell cycle would they act?

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

Explanation: Normally, DNA does uncoil and separate to replicate in the S-phase of interphase of cell cycle.To stop that from happening the drug or the chemicals must act on interphase.

Q24. Which statement concerning transpiration is correct?

• A. On a humid day, the water potential gradient between the intercellular air space and the external atmosphere increases, stimulating water loss by evaporation.
• B. Water arriving at the spongy mesophyll cells via the symplast pathway must move by osmosis through the cell surface membrane before evaporation from the surface of the cells.✓
• C. Water diffuses down the water potential gradient from the saturated air space through the guard cells before evaporating from the surface of the cells into the atmosphere.
• D. Water moves up the xylem in the apoplast pathway and can continue on this pathway by osmosis to reach the spongy mesophyll cells before evaporating into the intercellular air space.

Explanation: The most accurate explanation is given in Option B.Option A is wrong because on a humid day, the water potential gradient between intercellular air space and external atmosphere is in fact extremely low - not high.Option C is wrong because water doesn’t diffuse before the evaporation occurs - makes less of a sense.Option D is wrong because water doesn’t move up the xylem by apoplastic pathway.

Q25. Which features enable an organism to be identified as a prokaryote?I Cell wallII Circular DNAIII NucleusIV Ribosomes

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

Explanation: All prokaryotes have a Circular DNA.

Q26. Which type of molecule is the end product of translation?

• A. Amino acid
• B. mRNA
• C. Polypeptide✓
• D. tRNA
• E. ATP

Explanation: Translation produces a polypeptide from the mRNA molecule.mRNA is produced by transcription

Q27. What is the ecological definition of the term community?

• A. All the food webs in an ecosystem
• B. All the individuals of one species in an area
• C. All the organisms in an area✓
• D. The living organisms and their nonliving environment

Explanation: Community ecology, study of the organization and functioning of communities, which are assemblages of interacting populations of the species living within a particular area or habitat - basically option C.

Q28. Why is yeast used in bread - making?

• A. Aerobic respiration produces alcohol.
• B. Aerobic respiration produces carbon dioxide.
• C. Anaerobic respiration produces alcohol.
• D. Anaerobic respiration produces carbon dioxide.
• E. Both anaerobic respiration produces alcohol & anaerobic respiration produces carbon dioxide.✓

Explanation: Yeast is used in bread making anaerobic respiration produces carbon dioxide and alcohol - carbon dioxide which helps in cooking of bread.

Q29. Which features enable the aorta to withstand ventricular systole?

• A. Collagen fibres and elastin fibres✓
• B. Collagen fibres and smooth muscle
• C. Elastin fibres and endothelium
• D. Endothelium and smooth muscle

Explanation: Ventricular systole has a quite extreme pressure and to withstand that aorta must have strong fibres to withstand this pressure and elasticity, both of which are provided by collagen and elastin fibres respectively.

Q30. Which cells become memory cells in the immune response?I B-lymphocytesII T-lymphocytesIII Phagocytes

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

Explanation: Both I and II have the potential to become memory cells in the immune system because they both are lymphocytes - whilst all lymphocytes have the ability to form memory unlike innate cells like phagocytes or neutrophils.

Q31. After the starch is ingested, in which order do these processes occur?

• A. Absorption -> assimilation -> digestion
• B. Absorption -> digestion -> egestion
• C. Assimilation -> digestion -> absorption
• D. Digestion -> absorption -> assimilation✓
• E. Assimilation -> absorption -> digestion

Explanation: After the starch is ingested it should first be digested by digestive enzymes in the ileum and the mouth then it should be through the small intestine into the blood which takes it to the liver to assimilate it.

Q32. Which bones meet at the elbow joint and what kind of movement do they allow?

• A. BONES MOVEMENTHumerus and Scapula In one plane only
• B. BONES MOVEMENTHumerus and Scapula In three planes
• C. BONES MOVEMENTUlna and humerus In one plane only✓
• D. BONES MOVEMENTUlna and humerus In three planes

Explanation: At the elbow joint the humerus joins with ulna and radius and it allows movement only in one plane: as it is a hinge joint.

Q33. Cell bodies of _ neurons are always located inside the CNS.

• A. Sensory
• B. Motor
• C. Associative✓
• D. Reflex

Explanation: Interneurons, also known as associative neurons, are a type of neuron that primarily functions to relay signals between other neurons. They are located entirely within the central nervous system (CNS), connecting sensory neurons to motor neurons and facilitating communication and processing of information within the CNS.

Q34. On which date is a woman most likely to ovulate if the first day of menstrual loss was 1 February?

• A. 5 February
• B. 14 February✓
• C. 24 February
• D. 28 February
• E. 1 March

Explanation: Ovulation occurs normally on the 14th day of menstrual cycle.

Q35. Which part of the central nervous system controls the body’s water balance?

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

Explanation: Hypothalamus is responsible for producing the water balance as it controls the release of a hormone called antidiuretic hormone(ADH), which acts on the collecting duct cells.

Q36. What causes the observed change in skin temperature on exposure to cold air?

• A. Less blood flowing just below the skin✓
• B. Less blood going to the heart and lungs
• C. More blood flowing just below the skin
• D. More blood going to the heart and lungs

Explanation: Less blood flows below the skin as a result of exposure to cold air this occurs to prevent the heat from radiating to the surrounding and helping the body trapping more heat within the body.

Q37. Which pair contains organisms of different phyla?

• A. Moss, liverwort
• B. Mucor, rhizopus
• C. Moss, club moss✓
• D. Petunia, tobacco
• E. Star fish, brittle star

Explanation: Moss belongs to the phylum Bryophyta.Club Moss belongs to the phylum Lycophyta.

Q38. Of the following, which one best describes phenylketonuria?

• A. A vitamin deficiency resulting in abnormal metabolism of proteins
• B. An inherited metabolic disorder resulting in a lack of an enzyme✓
• C. A mineral deficiency resulting in abnormal bone formation
• D. An abnormal shape in red blood cells
• E. A chronic disease of unknown causes

Explanation: Phenylketonuria is a condition in which it occurs due to the lack of enzyme and is genetic in nature - that it transfers from parent to child.Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine - that occurs due to the deficiency of enzyme phenylalanine hydroxylase.

Q39. The diagram shows a cell of an organism formed by reduction division. What is the diploid number for this organism?

• A. 10
• B. 30
• C. 40
• D. 44✓

Explanation: Haploid cells are formed by reduction division, which has half the number of chromosomes than diploid cells. To calculate the diploid number of cells just multiply the chromosome number in the haploid number by 2. So, 22x2=44.

Q40. Which of the following is constructed from 5’ to 3’?

• A. Leading strand
• B. Lagging strand✓
• C. PCR products
• D. All of the given options

Explanation: The lagging strand is formed from 5’ to 3’ as the DNA polymerase works from 3’ to 5’ to form the leading strand - as shown in the diagram below:

Q41. Chlorine - type laundry bleaches are aqueous solutions of:

• A. HOCl✓
• B. HClO3
• C. NaClO3
• D. NaOCl

Explanation: Bleaching action of Cl2 is due to the reaction: Cl2+H2O→HCl+HOCl.HOCl bleaches by oxidation. Laundry bleaches are therefore aqueous solution of HOCl.Used to whiten and disinfect laundry.

Q42. When HNO3 is dropped into the palm and washed with water it turns into yellow. T shows the presence of:

• A. NO2
• B. N2O
• C. NO
• D. N2O5✓

Explanation: When HNO3 is dropped on the palm and then washed with the water and it turns into yellow colour, it is because in the skin or any body part, protein is present.When the HNO3 reacts with any protein, which in this case the hand which is keratinised so the protein which is present and it gives a yellow colour compound which is called xanthoprotein. Which contains N2O5.

Q43. The oxidation numbers of sulphur in S8 , S2F2 , H2S, respectively are:

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

Explanation: The oxidation state of elements is always 0 so the oxidation state of S8 is 0.To work out the oxidation state in S2F2

Q44. Alkyl halides are more reactive than alkanes. The reason being:

• A. The presence of a C - X bond in alkyl halides makes them more reactive.
• B. Alkyl halides can undergo inductive effect, enhancing their reactivity.
• C. The halogen (X) in alkyl halides bears a partial negative charge, contributing to their reactivity.
• D. All of these reasons contribute to the increased reactivity of alkyl halides compared to alkanes.✓

Explanation: With the exception of the fluoroalkane they are more reactive than alkanes principally due to two reasons: 1. C-X bond is polar due to the difference in electronegativity between carbon and X,there is a partial negative charge.The halogen which is electronegative will accept the electrons from the broken C-X bond and leave(inductive effect)

Q45. The amount of energy required to remove the most loosely bound electrons from an isolated gaseous atom from an element is known as:

• A. Electron affinity
• B. Potential energy
• C. Electronegativity
• D. Ionization energy✓
• E. Atomic radius

Explanation: Ionization energy is the quantity of energy that an isolated, gaseous atom in the ground electronic state must absorb to discharge an electron, resulting in a cation. H(g)→H+(g)+e− This energy is usually expressed in kJ/mol, or the amount of energy it takes for all the atoms in a mole to lose one electron each.

Q46. Which substance has diffused melting point?

• A. Crystalline solids
• B. Amorphous solids✓
• C. Metallic solids
• D. Covalent solids
• E. Ionic solids

Explanation: An amorphous solid does not have a definite melting point; instead, it melts gradually over a range of temperatures, because the bonds do not break all at once. This means an amorphous solid will melt into a soft, malleable state (think candle wax or molten glass) before turning completely into a liquid.

Q47. With increase in the value of Principal Quantum Number (n), the shape of the s-orbitals remains the same although their sizes:

• A. Decrease
• B. Increase✓
• C. Remain the same
• D. May or may not remain the same

Explanation: As the principal quantum number (n) increases, the size of the s-orbitals also increases. The shape of the s-orbitals remains spherical, with a probability distribution that becomes more spread out from the nucleus as n increases. So, while the shape (spherical) remains the same, the size of the orbital increases with higher values of n ( as shown in figure). This means that s-orbitals with larger principal quantum numbers have a higher probability of finding electrons farther away from the nucleus. Therefore, option B is correct.

Q48. Which of the following values of heat of formation indicates that the product is most stable?

• A. -94 K.Cals/mol
• B. -231.6 K.Cals/mol✓
• C. +21.4 K.Cals/mol
• D. +64.8 K.Cals/mol

Explanation: The more energy is lost to the surrounding the more stable the compound will be, as a matter of fact.Hence the B is the correct answer as it has the most negative enthalpy change.

Q49. Which of the following pairs has similar empirical formula?

• A. C2H2 & C6H6
• B. C4H8 & C2H4
• C. C5H10 & C6H12
• D. All have same empirical formula✓

Explanation: Empirical formula is the ratio of atoms of two elements in a compound. In option A , the ratio between two elements in both of the compounds is equal to 1. In option B, the ratio between two elements in both of the compounds is equal to ½ In option C, the ratio between two elements in both of the compounds is equal to ½ Hence option D is correct!

Q50. What functional groups ore present in the compound below ?

• A. Ester and ether
• B. Ester and amine
• C. Ether and Carboxylic acid✓
• D. Ether and ketone

Explanation: The correct answer is Option C: Ether and Carboxylic acid. The compound includes an ether functional group, characterized by an oxygen atom bonded between two carbon atoms (C--O--C), and a carboxylic acid functional group, which consists of a carbonyl group (C=O) bonded to a hydroxyl group (OH), forming the structure COOH. Options A and B are incorrect because they mention ester and amine groups, which are not present. Option D is incorrect because it suggests the presence of a ketone group, which is not in the compound.

Q51. A 8 grams of O2 gas contains:

• A. 25 mol
• B. 2.5 mol
• C. 0.25 mol✓
• D. 0.025 mol
• E. 0.001 mol

Explanation: There is a total of 32 grams(16+16) of Oxygen in 1 mole of oxygen molecule,so as the 8 grams thus forms ¼ th of the 32 grams, the number of moles of oxygen molecule is 1/4th of 1 i.e. 0.25!

Q52. A property of a system that depends only on the state of a system is called a:

• A. State action
• B. State reaction
• C. State function✓
• D. State of system
• E. None of these

Explanation: A property of a system that depends only on the state of a system is called state function.State function can also be defined as a quantity in thermodynamics, such as entropy or enthalpy, that has a unique value for each given state of a system.

Q53. In the reaction: H2(g) + I2(g) -> 2HI(g) ΔH = +12.40KJ/mole represents:

• A. Heat of formation✓
• B. Heat of neutralization
• C. Heat of oxidation
• D. Heat of sublimation
• E. Reduction

Explanation: In the equation above the compound is being formed from its constituent elements hence it is called formation process so the enthalpy is termed as enthalpy change of formation.

Q54. Chloroform (CHCl3) is miscible with acetone (CH3COCH3) due to:

• A. Dipole-dipole forces✓
• B. London dispersion forces
• C. H-Bonding
• D. Debye forces

Explanation: The chloroform and acetone are miscible liquids because they both are polar and possess dipole-dipole forces due to the presence of electronegative elements in them.H- bonding is the correct answer because for the compound to have hydrogen bonding it must have any of the three electronegative forces from: N,O,F bound to hydrogen atom.This is not the case in either of the molecules.

Q55. Which of the following has hydrogen bonding?

• A. C6H6
• B. Ice✓
• C. Paraffin
• D. O2
• E. All of these

Explanation: Hydrogen bonding is present in elements that have a more electronegative element from: N,O,F bound to a hydrogen atom, which is the only case in Ice whose formula is H2O.The formula for paraffin is CH4 and others also do not have hydrogen bond to N,O,F.

Q56. The correct I.U.P.A.C name of diethyl acetylene is:

• A. 1,2-diethyl ethyne
• B. 3-hexyne✓
• C. 2-hexyne
• D. 1-pentyne

Explanation: Two ethyl groups attached to each carbon of acetylene makes it a 6 carbon alkyne with triple bond at carbon number 3.

Q57. A limiting reactant is the one which:

• A. Is taken in lesser quantity in grams as compared to other reactants
• B. Is taken in lesser quantity in volume as compared to other reactants
• C. Gives the maximum amount of product which is required
• D. Gives the minimum amount of product under consideration✓

Explanation: Option D is correct because limiting reactant is a substance/reactant that has limits the progress of reaction by getting consumed first.Because of this limiting reactant the amount of product formed is minimum.

Q58. A reactant in a chemical reaction is non-conductor to electricity, colourless and non-responsive towards plane polarised light but can absorb ultraviolet rays. Then the best technique for the determination of initial rate of such a reaction:

• A. Polarimetry
• B. Refractometry
• C. Spectroscopy✓
• D. Colourimetry
• E. None of these

Explanation: Since UV rays are emitted from the chemical reaction, the best way to follow this reaction will be to use spectroscopy,which is used in physical and analytical chemistry to detect, determine, or quantify the molecular and/or structural composition of a sample. Each type of molecule and atom will reflect, absorb, or emit electromagnetic radiation in its own characteristic way.

Q59. Fats and oils are liable to spoilage and give a peculiar odour of an aldehyde, It is mainly due to the:

• A. Hydrolytic reactions
• B. Oxidative reactions
• C. Substitution reactions
• D. Both hydrolytic and oxidative reactions✓

Explanation: Rancidification is the process that leads to spoilage of fats and oil and give a peculiar odor to form aldehyde.This is mainly because of hydrolytic and oxidative reactions.

Q60. If an alkali is added to an aqueous solution that contains both dichromate and chromate ions in equilibrium the reaction will shift towards:

• A. Chromate ions✓
• B. Dichromate ions
• C. No effect on equilibrium position
• D. Prediction not possible

Explanation: When an alkali or base is added to a dichromate solution, there is a shift in the position of the chemical equilibrium. This shifts the equilibrium to the right i.e. the OH- ions removes H+ ions by neutralizing them and shifts the color. Thus, adding hydroxide ions or alkali converts dichromate to chromate, shifting the equilibrium towards chromate.

Q61. Hydrogen diffuses six times faster than gas A, The molar mass of gas A is:

• A. 16
• B. 36
• C. 6
• D. 24
• E. 72✓

Explanation: Hydrogen gas has a mass of 2g, diffusing six times faster than the means that hydrogen has six times less mass than that gas as rate of diffusion is indirectly proportional to the square of mass of the molecule of gas.2*(6)^2=72g.

Q62. The following reaction sequence is typical of SN1 reactions. Identify the rate limiting step(s).

• A. Step 1✓
• B. Step 2
• C. Steps 1 and 2
• D. None of these

Explanation: In the SN1 reaction only the first step is limiting from both of the steps.

Q63. What is the correct order of the boiling points of the following compounds?I n - hexaneII 2 - methylpentaneIII 2,2 - dimethylbutaneIV 3- methylpentane

• A. I > IV > II > III
• B. IV > III > II > I
• C. IV > I > II > III
• D. I > II > IV > III✓
• E. II > I > III > IV

Explanation: DETAILS GIVEN BELOW

Q64. Which of the following will have the largest ionic radius?

• A. Cs+✓
• B. Li+
• C. Na+
• D. Mg2+
• E. Ba2+

Explanation: Cs+ has the largest ionic radius because in all the ions mentioned above it is the only ion having a single positive charge while also being lowest in its group.GROUP II ions +2 charges can never be larger than Group I ions.

Q65. Interstitial compound is formed by:

• A. Fe, Co
• B. Co, Ni
• C. Fe, Ni
• D. All of these✓

Explanation: Transition metals such as Fe, Co and Ni form interstitial compounds. Thus, all the options are correct.

Q66. The reaction of 1 mole of diethyl ether with excess hydrobromic acid results in the production of:

• A. 2 moles of ethyl bromide
• B. 2 moles of ethanol
• C. 1 mole of ethyl bromide and 1 mole of ethanol✓
• D. 1 mole of methyl bromide and 1 mole of propanol
• E. 2 moles of methyl bromide

Explanation: When diethyl ether reacts with hydrobromic acid it forms ethyl bromide and ethanol. As shown in the schematic diagram below.

Q67. Which of the following principles limits the maximum number of electrons in an orbital?

• A. Aufbau Principle
• B. Pauli Exclusion Principle✓
• C. Hund’s Rule
• D. Heisenberg Uncertainty Principle
• E. None of these

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

Q68. Which of the following represents the correct structure for para-nitrotoluene?

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

Explanation: Option A- The given structure is of phenylmethaneamine or benzylamine. Option B- The given structure is of meta nitrotoluene. Option C- The correct structure for para-nitrotoluene is given in option C. Option D- The given structure is of 3-Methylbenzeneamine.

Q69. The pair that yields the same gaseous product on reaction with water:

• A. K and KO2
• B. Ca and CaH2✓
• C. Na and Na2O2
• D. Ba and BaO2

Explanation: Option B is correct and its equation are given as follows:Ca +H2O = Ca(OH)2 + H2CaH2 + H2O = Ca(OH)2 +H2

Q70. In the figure below, what is the correct name for the molecule shown in the Haworth projection?

• A. α - D - Glucose
• B. β - D - Glucose✓
• C. β - L - Glucose
• D. α - L - Glucose

Explanation: As mentioned in the picture above the answer is B.

Q71. A refrigerator has to transfer an average of 263 J of heat per second from -10 C to 25 C. Calculate the average power consumed. Assume that the refrigerator is ideal.

• A. 25 W
• B. 30 W
• C. 35 W✓
• D. 40 W
• E. 45 W

Explanation: Average power consumed=Pa=(1-T2/T1)*10= (1 -25/-10)*10=>((-10-25)/10)*10=>(-35/-10)*10=>35W

Q72. A capacitor is charged to a potential difference of 12 V. It delivers 40% of its stored energy to a lamp. What is the final potential difference across the capacitor?

• A. 4.3 V
• B. 4.8 V
• C. 7.2 V
• D. 9.3 V✓
• E. 1.0 V

Explanation: 60% will become 0.6 and we will multiply it by 12 we will get 7.2V. A capacitor is charged to a potential difference of 12V. It delivers 40% of its stored energy to the lamp. The final potential difference across capacitors is 9.295volts.

Q73. A line of force is an imaginary line drawn in such a way that the direction of the tangent at any of the points is the same as _ at that point.

• A. Magnetic field
• B. Electric field✓
• C. Electromagnetic field
• D. Gravitational field
• E. Strong field

Explanation: An electric field line is an imaginary line drawn in such a way that its direction at any point is the same as the direction of the field at that point. Field-line in general is a curve drawn in such a way that the tangent to it at each point in the direction of the net field at that point.

Q74. A current of 8 amperes is flowing in a wire. How many electrons pass a given point in the wire in one second, if the charge on an electron is 1.6 x 10-19 coulomb?

• A. 3.5 x 1019 electrons
• B. 5 x 1019 electrons✓
• C. 7.25 x 1019 electrons
• D. 2.75 x 1015 electrons
• E. 3.25 x 1017 electrons

Explanation: Total charge=Ampere x TimeQ=It=(8)*(1)=8C1e has a charge of 1.6*10^-19 C of charge.So 8C will have;n=8/(1.6*10^-19)n=5x10^9 electrons

Q75. A solenoid is a coil of insulated copper wire wound on a _.

• A. Long cylinder with wide turns
• B. Long cylinder with close turns✓
• C. Small cylinder with wide turns
• D. Small cylinder with close turns
• E. Medium cylinder with wide turns

Explanation: A solenoid is a coil of insulated or enameled wire wound closely on a rod-shaped form made of solid iron, solid steel, or powdered iron. Devices of this kind can be used as electromagnets, as inductors in electronic circuits, and as miniature wireless receiving antennas.

Q76. When X-rays are scattered by electrons their wavelength increases. This phenomenon is called:

• A. Compton Effect✓
• B. Thomson Effect
• C. Hall Effect
• D. Henry Effect
• E. None of these

Explanation: Compton scattering, discovered by Arthur Holly Compton, is the scattering of a photon by a charged particle, usually an electron. If it results in a decrease in energy (increase in wavelength) of the photon (which may be an X-ray or gamma ray photon), it is called the Compton effect.

Q77. In metallic conductors, there is always a large number of _ detached from their parent atom, which constitutes a kind of electron gas.Free electronsDispersed electronsInactive electrons

• A. 1 Only✓
• B. 2 Only
• C. 3 Only
• D. 2 & 3 Only
• E. 1, 2 & 3

Explanation: Metallic conductors have a large number of free electrons detached from their parent atom allowing them to conduct electricity - also called a kind of electron gas

Q78. A coil of 1200 turns is threaded by a flux of 12 x 10-5 Webers, if this flux is reduced to 3 x 10-5 webers in 0.015 seconds. The average induced e.m.f is:

• A. -7.2 volts✓
• B. -4.0 volts
• C. +5.0 volts
• D. +6.5 volts
• E. +8.0 volts

Explanation: The correct answer is -7.2 volts. According to Faraday's law of electromagnetic induction, the average induced e.m.f (E) in a coil is given by the equation: E = -n(Δϕ/Δt), where n is the number of turns in the coil, Δϕ is the change in magnetic flux, and Δt is the time interval over which the change occurs.For this question, n = 1200 turns, Δϕ = (12 x 10^-5 - 3 x 10^-5) Weber = 9 x 10^-5 Weber, and Δt = 0.015 seconds. Plugging these values into the formula gives: E = -(1200)(9 x 10^-5)/(0.015) = -7.2 volts.The other options are incorrect because they either use incorrect calculations or misunderstand the direction of the induced e.m.f (positive instead of negative).

Q79. The atomic number of an atom is the number of:

• A. Nucleons in the nucleus of an atom
• B. Atomic electrons in the neutral atom
• C. Protons in the nucleus of an atom✓
• D. Both Atomic electrons in the neutral atom & Protons in the nucleus of an atom
• E. None of these

Explanation: The atomic number of an atom is the number of protons in the nucleus of an atom.Nucleons in the nucleus of an atom are represented by the mass number.

Q80. The material consisting of the fissionable isotope is called as:I ModeratorII Reactor fuelIII Coolant

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

Explanation: The fuel powers the nuclear reaction thus must have fissionable isotope to start a chain reaction.

Q81. Which of the following quantity/ies is/are not vector?

• A. Velocity
• B. Force
• C. Displacement
• D. Distance✓
• E. All of these

Explanation: Vector quantity is one that has magnitude as well as a direction which is true for quantities like velocity,force,and displacement,but not for distance which is a scalar quantity that exists irrespective of the direction.

Q82. A ball is projected vertically upwards from the ground with a velocity of 20 m/s. How high will it go? (Take g = 10 m/s2)

• A. 5 m
• B. 10 m
• C. 15 m
• D. 20 m✓
• E. 25 m

Explanation: v²=u²−2gh v²=u²−2gh Here, v=0m/s, u= 20m/s, g=10m/s²(approx) Substituting these values we get, H= 20 m. So the ball will go upto 20m height.

Q83. A car is traveling with uniform acceleration along a straight road. The road has marker posts every 100 m. When the car passes one post, it has a speed of 10 m/s and when it passes the next one, its speed is 20 m/s. What is the car's acceleration?

• A. 0.67 m/s2
• B. 1.5 m/s2✓
• C. 2.5 m/s2
• D. 6.0 m/s2

Explanation: A car is travelling with uniform acceleration along a straight road. The road has marker posts every 100 m, d = 100 mInitial speed of the car, u = 10 m/sFinal speed of the car, v = 20 m/sLet a is the acceleration of the car. It is equal to the rate of change of velocity per unit time.

Q84. A 2,500 kg car traveling at 20 m/s crashes into a 6, 000 kg truck that is originally at rest. What is the speed of the truck after the collision, if the car comes to rest at the point of impact? (Neglect the effects of friction.)

• A. 0 m/s
• B. 8.33 m/s✓
• C. 16.7 m/s
• D. 83 m/s
• E. 14 m/s

Explanation: Using law of conservation of linear momentum,Initial linear momentum = final linear momentumHere initial linear momentum = m₁u₁ + m₂u₂initial velocity of car, u₁ = 20 m/sinitial velocity of truck, u₂ = 0So, initial linear momentum = 2500 × 20 kgm/s + 0 = 50,000 kgm/sFinal linear momentum = m₁v₁ + m₂v₂final velocity of car, v₁ = 0 m/sfinal velocity of truck, v₂ = ?so, final linear momentum = 2500 × 0 + 6000 × v₂ = 6000v₂Now, initial linear momentum = final linear momentum⇒50,000 = 6,000v₂⇒v₂ = 50/6 = 8.33 m/sTherefore the speed of the truck after collision is 8.33 m/s

Q85. The ratio of limiting friction to the normal reaction acting between two surfaces in contact is called:

• A. Viscosity
• B. Coefficient of friction✓
• C. Fluid friction
• D. Sliding friction
• E. None of these

Explanation: For any two surfaces in contact, the magnitude of limiting friction is directly proportional to the normal reaction between two surfaces.The magnitude of limiting friction is directly proportional to normal reaction(R)i.e F = μ Rtherefore μ = F/RThus coefficient of limiting friction is the ratio between limiting friction to the normal reaction.

Q86. In the application of projectile motion, the small-angle produces _ trajectory and the large angle produces _ trajectory.

• A. Flat … flat
• B. High … high
• C. Flat … high✓
• D. High … flat
• E. High … low

Explanation: A smaller angle should produce a flatter and lower trajectory, unlike when we have a larger angle that should produce a higher trajectory.This can inferred from common sense that smaller the angle object will have with the floor the lower the trajectory will be.

Q87. Find the maximum speed at which a car turns around a curve of 30 m radius on a level road if the coefficient of friction between the tires and the road is 0.4.

• A. 5.74 m/s
• B. 6.74 m/s
• C. 8.94 m/s
• D. 10.84 m/s✓
• E. 12.84 m/s

Explanation: Radius of curve Coefficient of friction Acceleration due to gravity To Find: Maximum speed, Frictional force is given by, Where Therefore, the maximum speed at which a car can turn round is 10.95

Q88. A child of mass ‘m’ stands on a board of mass ‘M’ which lies on a frictionless horizontal surface. The child starts walking with a speed ‘v’ with respect to the ground. With what speed does the board recoil?

• A. 2mv/m2
• B. mv/M✓
• C. v/M
• D. v2/M
• E. 2vM

Explanation: Option B is correct.

Q89. An astronaut weighs 700 N on Earth. What is the best approximation of his new weight on a planet with a radius that is two times that of Earth, and a mass three times that of Earth?

• A. 200 N
• B. 500 N✓
• C. 700 N
• D. 900 N
• E. 1200 N

Explanation: Attached

Q90. Initially, four identical uniform blocks, each of mass m and thickness h, are spread on a table.How much work is done on the blocks in stacking them on top of one another?

• A. 2 mgh
• B. 3 mgh
• C. 4 mgh
• D. 6 mgh✓
• E. 9 mgh

Explanation: To stack them all on each other, we only need to lift 3 of them, with the remaining lowest one already being on the table. When on the ground, a block has zero gravitational potential energy. When at a height x above the ground, the gravitational potential energy of the block is mgx. So, the work that needs to be done to lift a block from the ground to a height x is equal to mgx.So first, we need to lift 1 block by a height h: Work done is mgh.Then, we need to lift 1 block by a height 2h: Work done is mg(2h) = 2mghFinally, we need to lift 1 block by a height 3h: Work done is mg(3h) = 3mghTotal work done = mgh + 2mgh + 3mgh = 6mgh

Q91. A raindrop of mass m is falling vertically through the air with a steady speed v. The raindrop experiences a retarding force kv due to the air, where k is a constant. The acceleration of free fall is g. Which expression gives the kinetic energy of the raindrop?

• A. mg/k
• B. mg2/2k2
• C. m3g2/2k
• D. m3g2/2k2✓
• E. m2g/k

Explanation: For raindrops to fall with a steady speed v, terminal speed must be reached (net force and thus, net acceleration is zero).This occurs when the retarding force kv equals to the weight mg.So, mg = kv giving v = mg / k.Kinetic energy of raindrop,

Q92. A body of mass 2kg, initially at rest, is acted upon simultaneously by two forces, one of 4 N and the other of 3 N acting at right angles to each other. Find the kinetic energy of the body after 20 seconds.

• A. 2500 J✓
• B. 3500 J
• C. 3600 J
• D. 3700 J
• E. 3900 J

Explanation: Since they're at right angles you can use the pythagorean theorem to add them together and find out the total force on the object which would be sqrt(3^2 4^2)=5NThe acceleration would be 5N/2KG=2.5M/S^2The velocity after 20 seconds would be 20S*2.5M/S^2=50M/SThe equation for kinetic energy is (Mass*velocity^2)/2 which is (2*50^2)/2 which is 2500 and the units are (KGM^2)/S^2 which are Joules so the answer is: 2500 joules

Q93. Two springs fixed at one end are stretched by 5 cm and 10 cm, respectively, when masses 0.5 kg and 1 kg are suspended at their lower ends. When displaced slightly from their mean positions and released, they will oscillate with time periods in the ratio

• A. 1:√2✓
• B. 1:2
• C. 2:1
• D. √2:1

Explanation: This is the correct answer. The time period of a spring-mass system is given by T = 2π√(m/k), where T is the time period, m is the mass, and k is the spring constant. Since the spring constant is the same for both springs (as the same force produces the same extension), the ratio of the time periods will only depend on the ratio of the masses: T1/T2 = √(m1/m2). Substituting the given masses, we get T1/T2 = √(0.5 kg / 1 kg) = √(1/2) = 1/√2.

Q94. A sound wave of frequency 400 Hz is traveling in a gas at a speed of 320 ms-1 . What will be its wavelength?

• A. 0.8 m✓
• B. 1.8 m
• C. 2.8 m
• D. 3.8 m
• E. 4.8 m

Explanation: Using the formula v=fλ320=400λλ=320/400=0.8m

Q95. A diffraction grating has a spacing of 1.6 x 10-6 m. A beam of light is incident normally on the grating. The first order maximum makes an angle of 20 degrees with the undeviated beam. What is the wavelength (approx) of the incident light? (sin20 = 0.342)

• A. 210 nm
• B. 270 nm
• C. 420 nm
• D. 550 nm✓
• E. 690 nm

Explanation: Given = d = 1.6 X 10m θ = 20°=0.342 n = 1to find = wavelength( λ)solution :-apply the, λ = d sinθ / n λ = 1.6 X 10 X 0.342 / 1 λ = 0.5472nm≅ 550 nmso the final wavelength of incident light is 550nm.

Q96. Identify the use/s of radiation: Identify the use/s of radiation:I PolymerizationII Sterilization and Food PreservationIII Radiography

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

Explanation: All of the above are uses of radiation; it is a factual recall from the textbook.

Q97. When the magnification of a lens is less than 1, it means that the image is actually:

• A. Larger than the object
• B. Smaller than the object✓
• C. Equal to the object
• D. Magnification does not affect the size of the image
• E. None of these

Explanation: When the magnification of a lens is less than 1, it signifies that the image produced by the lens is smaller in size compared to the actual object. This is a fundamental concept in optics and lens behaviorThe magnification of a lens is given by the formula:Magnification (M) = Height of Image (hi) / Height of Object (ho)When the magnification of a lens is less than 1, it indicates that the height of the image (hi) is smaller than the height of the object (ho). In other words, the image produced by the lens is smaller in size compared to the actual object.

Q98. Bragg’s equation is used to find out the spacing ‘d’ between atomic similar parallel planes of a crystal. Which option gives the correct formula?

• A. d = mλ / 2sinθ✓
• B. d = λ / 2mSinθ
• C. d = 2λ / mSinθ
• D. d = 3λ / mSinθ
• E. d = 3λ / 2mSinθ

Explanation: Option A(d=mλ / 2sinθ) correctly depicts Bragg's equation.

Q99. When a relaxed human eye produces an image of a distant object behind the retina, this abnormality is known as:

• A. Hyperopia
• B. Short sightedness
• C. Myopia
• D. Farsightedness
• E. Both Hyperopia & Farsightedness✓

Explanation: The condition described is when the image forms behind the retina, which is known as hyperopia or farsightedness. These terms refer to the same visual abnormality, where distant objects are seen more clearly than near objects. This occurs because the eyeball is too short, or the lens is not curved enough, causing light to focus behind the retina. Converging lenses are used to correct this by moving the focal point forward onto the retina. Myopia, or short sightedness, is the opposite condition where images focus in front of the retina, making distant objects appear blurry.

Q100. In an adiabatic compression process, the internal energy of the gas:

• A. Increases, because the work done on the gas is negative
• B. Increases, because the work done on the gas is positive✓
• C. Decreases, because the work done on the gas is negative
• D. Decreases, because the work done on the gas is positive
• E. Remains the same, because the work done on the gas is positive

Explanation: During adiabatic processes, the change in heat energy is zero.So the equation is U=q+w; where work done on the gas is positive.Since q is zero; and work done(w) on the gas is taken as positive,the internal energy would increase according to the above equation.