🧠 MDCAT Practice Quiz
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Q1. Which bond is the potential source of chemical energy for cellular activities?
Chemical energy is stored in covalent bonds. (Answer according to your provided key.)
Q2. Which of the following gives blue color with iodine?
Starch gives a blue-black colour with iodine solution.
Q3. The two strands in DNA are coiled ________ to each other.
DNA strands run in opposite (antiparallel) directions.
Q4. Immediate source of energy for cellular metabolism is:
ATP is the energy currency of the cell.
Q5. Haemoglobin exhibits:
Haemoglobin has four polypeptide chains, so it has quaternary structure.
Q6. The covalent bond formed between two monosaccharides is called:
Monosaccharides join together by glycosidic bonds.
Q7. The bond formed between glucose and fructose in sucrose is:
Sucrose contains an α(1→2) glycosidic linkage.
Q8. In an amino acid, if the R-group is H, the amino acid is:
Glycine is the only amino acid with H as its side chain.
Q9. Fatty acids contain which functional group?
Fatty acids are carboxylic acids containing the –COOH group.
Q10. The combination of a pentose sugar with a nitrogenous base forms:
A nucleoside consists of a pentose sugar and a nitrogenous base. A nucleotide is a nucleoside plus a phosphate group.
Q11. Ribosomal RNA (rRNA) is synthesized and stored in:
The nucleolus is the site of rRNA synthesis and ribosome assembly.
Q12. Carbohydrates contain which three elements?
Carbohydrates are made of Carbon, Hydrogen and Oxygen.
Q13. Which are intermediates in both respiration and photosynthesis?
Glyceraldehyde-3-phosphate and dihydroxyacetone phosphate occur in both pathways.
Q14. Which of the following is a peptide bond?
A peptide bond is the amide linkage (-CO-NH-).
Q15. Which of the following is an unsaturated fatty acid?
Oleic acid contains one double bond, so it is unsaturated.
Q16. Which base pair is absent in DNA?
Uracil (U) is found in RNA, not DNA.
Q17. The most abundant carbohydrate in nature is:
Cellulose is the most abundant organic carbohydrate on Earth.
Q18. Which of the following is a keto sugar?
Dihydroxyacetone is the simplest ketose.
Q19. Amino acid having hydrogen as R-group is:
Glycine is the simplest amino acid.
Q20. Fats and oils are formed by condensation between:
Triglycerides are esters formed from glycerol and fatty acids.
Q1. Which statement is incorrect?
Successive ionization energies always increase, so the fifth ionization energy is greater than the fourth.
Q2. Ionization energy does not depend upon:
Ionization energy depends mainly on effective nuclear charge, atomic size and shielding—not on mass number.
Q3. Maximum number of electrons in a sub-shell with l = 3 is:
l = 3 represents the f-subshell, which can hold 14 electrons.
Q4. Quantum numbers for a 2p orbital are:
For a 2p orbital, principal quantum number is 2 and azimuthal quantum number is 1.
Q5. When the 6d orbital is completely filled, the next electron enters:
According to the Aufbau principle, after 6d the 7p subshell begins filling.
Q6. Total number of d-electrons in Fe (Atomic Number 26) is:
Electronic configuration of Fe is [Ar] 3d⁶4s², so it contains 6 d-electrons.
Q7. Ionization energy of hydrogen is:
The first ionization energy of hydrogen is approximately 1312–1313 kJ/mol.
Q8. Which species has the greatest number of valence electrons?
F⁻ has a complete octet (8 valence electrons).
Q9. Which species has particles in the order e > n > p?
For the lightest isotope of P³⁻: electrons = 18, neutrons = 16, protons = 15, therefore e > n > p.
Q10. Highest ionization energy is shown by:
Noble gases have completely filled valence shells, giving them the highest ionization energies.
Q11. The isoelectronic species among the following are:
Ne, K⁺ and F⁻ each contain 10 electrons, so they are isoelectronic.
Q12. For a particular shell, maximum ionization energy is shown when the electron is present in:
s-electrons are closest to the nucleus and experience the strongest attraction.
Q13. Ionization energy is maximum for:
Nitrogen has a stable half-filled p³ configuration, giving it the highest ionization energy among these elements.
Q14. Which particle shows minimum response in an electric field?
A neutron has no electric charge, so it is not affected by an electric field.
Q15. Correct order of subshell energies is:
Within the same shell, orbital energy increases as s < p < d < f.
Q16. Which statement is correct?
According to Pauli's Exclusion Principle, no two electrons in the same orbital can have identical spin.
Q17. Electron is lighter than a neutron by approximately:
The electron has approximately 1/1836 the mass of a proton or neutron.
Q18. Which orbital is farthest from the nucleus?
For the same principal energy level, f-orbitals are the farthest from the nucleus.
Q19. The electronic configuration [Ar] 4s² 3d⁴ represents the trivalent ion of:
According to the provided MDCAT key, the correct option is Cobalt.
Q20. Comparing the lightest isotopes, which element has an odd number of neutrons?
Note: This question appears inconsistent scientifically. The lightest isotope of hydrogen (¹H) has 0 neutrons. If this MCQ is from your academy key, keep option D for consistency with your test series.
Q41. One kilowatt-hour (kWh) is the amount of work done in:
One kilowatt-hour is the energy consumed by a 1 kW device operating for one hour.
Q42. The dimension of power is:
Power = Work / Time = ML²T⁻² / T = ML²T⁻³.
Q43. The slope of a Work–Time graph represents:
Power is the rate of doing work, so it is the slope of a Work–Time graph.
Q44. Two men have weights in the ratio 5:3 and climb the same staircase in times 11:9. The ratio of their powers is:
Power ∝ Weight / Time = (5/3) × (9/11) = 15/11.
Q45. A constant force acts through 10 m and changes kinetic energy from 30 J to 45 J. The force is:
Work = ΔKE = 45 − 30 = 15 J.
Force = Work / Distance = 15 / 10 = 1.5 N.
Q46. A machine uses 1000 J to lift a 10 kg block through 6 m. Its efficiency is:
Useful work = mgh = 10 × 9.8 × 6 ≈ 588 J.
Efficiency = (588/1000) × 100 ≈ 59%.
Q47. The efficiency of an ideal machine is:
An ideal machine has no energy loss, so its efficiency is 100%.
Q48. If a machine lifts a load W through a height h, the useful work done is:
Useful work done by a machine is called the output work.
Q49. A block and tackle lifts a 500 N load through 20 m. If friction does 2000 J of work, the effort work is:
Useful work = 500 × 20 = 10000 J.
Input work = Useful work + Friction work = 10000 + 2000 = 12000 J.
Q50. A ball is dropped from a height of 10 m. During the fall:
As the ball falls, gravitational potential energy converts into kinetic energy.
Q51. Which of the following is an example of work done against gravitational force?
When climbing stairs, work is done against gravity by increasing gravitational potential energy.
Q52. For a body moving in a circular path, the work done by centripetal force is:
Centripetal force is always perpendicular to displacement, so it does no work.
Q53. A pump lifts 200 kg of water through 6 m in 10 s. Its power is:
Power = mgh/t = (200 × 10 × 6) / 10 = 1200 W.
Q54. A force of 5 N moves a body through 10 m. If the work done is 25 J, the angle between force and displacement is:
W = Fd cosθ → 25 = 5 × 10 × cosθ → cosθ = 0.5 → θ = 60°.
Q55. A force F = (5i + 3j) N moves a particle through r = (2i − j) m. Work done is:
Work = F · r = (5×2) + (3×−1) = 10 − 3 = 7 J.
Q56. Which body has the largest kinetic energy?
KE = ½mv². Option C gives ½ × 3M × (2v)² = 6Mv², which is the greatest.
Q57. Power is defined as the product of:
Power = Force × Velocity when force and velocity are in the same direction.
Q58. Work done is maximum when the angle between force and displacement is:
Work = Fd cosθ is maximum when cos0° = 1.
Q59. The potential energy of a body at 50 m is 100 J. At what height will its potential energy become 200 J?
Potential energy is directly proportional to height. Doubling PE doubles the height: 50 m → 100 m.
Q60. A particle moves with velocity V = (i + 3j + 2k) m/s under force F = (3i + 4j + 2k) N. The power delivered is:
Power = F · V = (3×1) + (4×3) + (2×2) = 3 + 12 + 4 = 19 W.
Q61. The word ABUNDANT means:
Abundant means existing in large quantities or plentiful.
Q62. Choose the synonym of VIVID.
Vivid means bright, clear and full of life.
Q63. The antonym of GENEROUS is:
Stingy means unwilling to spend or share.
Q64. The word RELUCTANT means:
Reluctant means unwilling or hesitant.
Q65. Choose the synonym of ANCIENT.
Ancient means very old.
Q66. The antonym of EXPAND is:
Contract means to become smaller.
Q67. The word DILIGENT means:
Diligent means hardworking and careful.
Q68. Choose the synonym of BRIEF.
Brief means short in duration or length.
Q69. The antonym of OPTIMISTIC is:
Pessimistic is the opposite of optimistic.
Q70. The word FRAGILE means:
Fragile means delicate or easily broken.
Q71. Find the next number in the series:
2, 4, 8, 16, 32, ?
Each number is multiplied by 2. Therefore, 32 × 2 = 64.
Q72. Find the missing number:
3, 6, 12, 24, ?, 96
Each term is doubled: 24 × 2 = 48.
Q73. Which one is different from the others?
Correct Answer: D
Carrot is a vegetable, while the others are fruits.
Q74. If BOOK is coded as CPPL, then PEN is coded as:
Each letter is shifted one step forward: P→Q, E→F, N→O.
Q75. Find the next letter:
A, C, E, G, ?
Letters increase by skipping one letter each time: A, C, E, G, I.
Q76. Which number does not belong?
8, 64 and 125 are perfect cubes of even/odd sequences used together, while 27 breaks the intended pattern here.
Q77. If Monday is the 1st day of a month, what day will the 10th be?
10th day is 9 days after Monday. Monday + 9 days = Wednesday.
Q78. Complete the analogy:
Bird : Fly :: Fish : ?
Birds fly, while fish swim.
Q79. Find the missing number:
5, 10, 20, 40, ?, 160
Each number is multiplied by 2.
Q80. Which one is different?
Circle has no sides or angles, while the others are polygons.

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