3782 lines
145 KiB
JSON
3782 lines
145 KiB
JSON
[
|
||
{
|
||
"id": "ed983451-f089-4925-8861-67f0c4d47fec",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Units and Measurements",
|
||
"subtopic": "Significant Figures",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The length and breadth of a rectangular metal sheet are measured as $3.32$ cm and $2.15$ cm respectively. Keeping the correct number of significant figures, the area of the sheet should be written as:",
|
||
"options": {
|
||
"A": "$7.138\\ \\text{cm}^2$",
|
||
"B": "$7.140\\ \\text{cm}^2$",
|
||
"C": "$7.1\\ \\text{cm}^2$",
|
||
"D": "$7.14\\ \\text{cm}^2$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Area $=3.32\\times 2.15=7.138\\ \\text{cm}^2$. Each factor has 3 significant figures, so the product is rounded to 3 significant figures: $7.14\\ \\text{cm}^2$."
|
||
},
|
||
{
|
||
"id": "cfa41d19-3907-4c91-b96f-2b194e2bcd72",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Kinematics",
|
||
"subtopic": "Equations of Motion",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A car moving with a speed of $72\\ \\text{km h}^{-1}$ is brought to rest with uniform retardation in $5$ s. The distance travelled by the car before coming to rest is:",
|
||
"options": {
|
||
"A": "$200\\ \\text{m}$",
|
||
"B": "$100\\ \\text{m}$",
|
||
"C": "$50\\ \\text{m}$",
|
||
"D": "$25\\ \\text{m}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "$u=72\\ \\text{km h}^{-1}=20\\ \\text{m s}^{-1}$, $a=(0-20)/5=-4\\ \\text{m s}^{-2}$. Using $v^2=u^2+2as$: $s=u^2/2a=400/8=50\\ \\text{m}$."
|
||
},
|
||
{
|
||
"id": "b81586dd-f6c6-40ee-8592-6fb5f312efd7",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Kinematics",
|
||
"subtopic": "Velocity-Time Graph",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The velocity of a body starting from rest increases uniformly from $0$ to $20\\ \\text{m s}^{-1}$ in the first $10$ s and then remains constant at $20\\ \\text{m s}^{-1}$ for the next $10$ s. The total distance covered by the body in $20$ s is:",
|
||
"options": {
|
||
"A": "$200\\ \\text{m}$",
|
||
"B": "$250\\ \\text{m}$",
|
||
"C": "$400\\ \\text{m}$",
|
||
"D": "$300\\ \\text{m}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Distance = area under $v$-$t$ graph $=\\frac{1}{2}\\times 10\\times 20 + 10\\times 20 = 100 + 200 = 300\\ \\text{m}$."
|
||
},
|
||
{
|
||
"id": "1622a663-f954-4327-b349-a6e82612d76c",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Kinematics",
|
||
"subtopic": "Projectile Motion",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A projectile is thrown with a speed of $20\\ \\text{m s}^{-1}$. Its maximum horizontal range on the ground is ($g = 10\\ \\text{m s}^{-2}$):",
|
||
"options": {
|
||
"A": "$20\\ \\text{m}$",
|
||
"B": "$40\\sqrt{2}\\ \\text{m}$",
|
||
"C": "$30\\ \\text{m}$",
|
||
"D": "$40\\ \\text{m}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Range $R=\\dfrac{u^2\\sin 2\\theta}{g}$ is maximum at $\\theta=45^\\circ$, where $R_{max}=u^2/g=400/10=40\\ \\text{m}$."
|
||
},
|
||
{
|
||
"id": "f1144f24-8751-4690-ba66-88a512a7e6ac",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Laws of Motion",
|
||
"subtopic": "Apparent Weight in Lift",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A man of mass $60$ kg stands on a weighing machine inside a lift accelerating upwards with $2\\ \\text{m s}^{-2}$. The reading of the machine is ($g = 10\\ \\text{m s}^{-2}$):",
|
||
"options": {
|
||
"A": "$780\\ \\text{N}$",
|
||
"B": "$480\\ \\text{N}$",
|
||
"C": "$720\\ \\text{N}$",
|
||
"D": "$600\\ \\text{N}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "$N = m(g+a) = 60(10+2) = 720\\ \\text{N}$. The machine reads the normal reaction, which increases when the lift accelerates upward."
|
||
},
|
||
{
|
||
"id": "61372ea3-0c16-4dd5-ae56-c22241eef3d3",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Laws of Motion",
|
||
"subtopic": "Static and Kinetic Friction",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A block of mass $5$ kg rests on a rough horizontal surface with $\\mu_s = 0.2$. A horizontal force of $8$ N is applied to it ($g = 10\\ \\text{m s}^{-2}$). The friction force acting on the block and its acceleration are:",
|
||
"options": {
|
||
"A": "$2\\ \\text{N},\\ 1.6\\ \\text{m s}^{-2}$",
|
||
"B": "$8\\ \\text{N},\\ 0\\ \\text{m s}^{-2}$",
|
||
"C": "$10\\ \\text{N},\\ 0\\ \\text{m s}^{-2}$",
|
||
"D": "$10\\ \\text{N},\\ 1.6\\ \\text{m s}^{-2}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Maximum static friction $f_{max}=\\mu_s mg=0.2\\times 50=10\\ \\text{N}>8$ N. The block does not move; static friction adjusts itself to balance the applied force, i.e. $f=8$ N and $a=0$."
|
||
},
|
||
{
|
||
"id": "cfd1cab7-7c3e-4943-a58d-7b6ae4dcb637",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Work, Energy and Power",
|
||
"subtopic": "Work-Energy Theorem",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A block of mass $2$ kg kept on a frictionless horizontal surface is acted upon by a constant horizontal force of $10$ N over a distance of $5$ m, starting from rest. The final speed of the block is:",
|
||
"options": {
|
||
"A": "$10\\ \\text{m s}^{-1}$",
|
||
"B": "$5\\sqrt{2}\\ \\text{m s}^{-1}$",
|
||
"C": "$10\\sqrt{2}\\ \\text{m s}^{-1}$",
|
||
"D": "$5\\ \\text{m s}^{-1}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Work done $W=Fs=10\\times 5=50$ J $=\\frac{1}{2}mv^2 \\Rightarrow v=\\sqrt{2W/m}=\\sqrt{100/2}=5\\sqrt{2}\\ \\text{m s}^{-1}$."
|
||
},
|
||
{
|
||
"id": "bec0aab9-41e5-4f82-933b-972cf30e711d",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Work, Energy and Power",
|
||
"subtopic": "Inelastic Collision and Spring Energy",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A bullet of mass $10$ g moving horizontally with $400\\ \\text{m s}^{-1}$ embeds itself in a wooden block of mass $990$ g resting on a smooth horizontal floor. The block, compressing a light spring of stiffness $k$ fixed at the wall, comes to rest when the spring is compressed by $10$ cm. The value of $k$ is:",
|
||
"options": {
|
||
"A": "$3200\\ \\text{N m}^{-1}$",
|
||
"B": "$800\\ \\text{N m}^{-1}$",
|
||
"C": "$1600\\ \\text{N m}^{-1}$",
|
||
"D": "$6400\\ \\text{N m}^{-1}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "By momentum conservation, common velocity $v=\\dfrac{0.01\\times 400}{1.0}=4\\ \\text{m s}^{-1}$. KE $=\\frac{1}{2}\\times 1\\times 16=8$ J. Energy conservation: $\\frac{1}{2}kx^2=8$ with $x=0.1$ m $\\Rightarrow k=16/0.01=1600\\ \\text{N m}^{-1}$."
|
||
},
|
||
{
|
||
"id": "a6963bd2-18b4-4310-bbd4-983b8e178e65",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Rotational Motion",
|
||
"subtopic": "Rolling Motion",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A solid sphere rolls without slipping on a horizontal plane. The ratio of its rotational kinetic energy to its total kinetic energy is:",
|
||
"options": {
|
||
"A": "$\\dfrac{1}{2}$",
|
||
"B": "$\\dfrac{2}{7}$",
|
||
"C": "$\\dfrac{5}{7}$",
|
||
"D": "$\\dfrac{2}{5}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "For a solid sphere $I=\\frac{2}{5}mR^2$. $K_{rot}=\\frac{1}{2}I\\omega^2=\\frac{1}{5}mv^2$ and $K_{total}=\\frac{1}{2}mv^2+\\frac{1}{5}mv^2=\\frac{7}{10}mv^2$. Ratio $=\\frac{1/5}{7/10}=\\frac{2}{7}$."
|
||
},
|
||
{
|
||
"id": "94aba0b6-52ab-4d02-b52e-2b4c496e369e",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Rotational Motion",
|
||
"subtopic": "Conservation of Angular Momentum",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A disc of moment of inertia $I$ is rotating about its axis with angular speed $\\omega$. Another identical disc, initially at rest, is gently dropped coaxially onto it. The two discs then rotate together with angular speed:",
|
||
"options": {
|
||
"A": "$\\omega$",
|
||
"B": "$\\dfrac{\\omega}{4}$",
|
||
"C": "$\\dfrac{\\omega}{2}$",
|
||
"D": "$2\\omega$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Angular momentum is conserved about the common axis: $I\\omega=(2I)\\omega' \\Rightarrow \\omega'=\\omega/2$. (Half of the initial rotational KE is lost in friction.)"
|
||
},
|
||
{
|
||
"id": "86b2ad82-b30b-4656-bcb3-17ef0b2f56e4",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Gravitation",
|
||
"subtopic": "Orbital Velocity",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A satellite is orbiting the Earth at a distance $2R$ from the centre of the Earth, where $R$ is the radius of the Earth. Its orbital speed is ($g = 10\\ \\text{m s}^{-2}$, $R = 6400$ km):",
|
||
"options": {
|
||
"A": "$5.7\\ \\text{km s}^{-1}$",
|
||
"B": "$11.2\\ \\text{km s}^{-1}$",
|
||
"C": "$7.9\\ \\text{km s}^{-1}$",
|
||
"D": "$8.0\\ \\text{km s}^{-1}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$v_{orb}=\\sqrt{GM/r}=\\sqrt{gR^2/2R}=\\sqrt{gR/2}=\\sqrt{10\\times 6.4\\times 10^6/2}\\approx 5.7\\ \\text{km s}^{-1}$."
|
||
},
|
||
{
|
||
"id": "2a4b2b86-0921-4c7f-baf9-dca75869b989",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Gravitation",
|
||
"subtopic": "Variation of g",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The acceleration due to gravity at a depth $R/2$ below the surface of the Earth, where $R$ is the radius of the Earth, is ($g = 10\\ \\text{m s}^{-2}$ at the surface):",
|
||
"options": {
|
||
"A": "$5\\ \\text{m s}^{-2}$",
|
||
"B": "$20\\ \\text{m s}^{-2}$",
|
||
"C": "$10\\ \\text{m s}^{-2}$",
|
||
"D": "$2.5\\ \\text{m s}^{-2}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Inside the Earth $g_d=g\\left(1-\\dfrac{d}{R}\\right)=10\\left(1-\\dfrac{1}{2}\\right)=5\\ \\text{m s}^{-2}$."
|
||
},
|
||
{
|
||
"id": "f96167a0-e165-4604-b9cd-b368475e5284",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Properties of Bulk Matter",
|
||
"subtopic": "Bernoulli's Theorem",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A small hole is made at the bottom of a tank filled with water to a depth of $5$ m. The speed of efflux of water from the hole is (neglect viscosity, $g = 10\\ \\text{m s}^{-2}$):",
|
||
"options": {
|
||
"A": "$5\\ \\text{m s}^{-1}$",
|
||
"B": "$10\\ \\text{m s}^{-1}$",
|
||
"C": "$20\\ \\text{m s}^{-1}$",
|
||
"D": "$100\\ \\text{m s}^{-1}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "By Torricelli's law, $v=\\sqrt{2gh}=\\sqrt{2\\times 10\\times 5}=10\\ \\text{m s}^{-1}$."
|
||
},
|
||
{
|
||
"id": "6d136a4c-c86d-4dee-800f-04977df8f4b9",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Properties of Bulk Matter",
|
||
"subtopic": "Viscosity and Terminal Velocity",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A small spherical ball falls through a viscous liquid with terminal velocity $v$. If another ball of the same material but half the radius is dropped in the same liquid, its terminal velocity will be:",
|
||
"options": {
|
||
"A": "$4v$",
|
||
"B": "$\\dfrac{v}{4}$",
|
||
"C": "$2v$",
|
||
"D": "$\\dfrac{v}{2}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Terminal velocity $v_t=\\dfrac{2r^2(\\rho-\\sigma)g}{9\\eta}\\propto r^2$. Halving the radius reduces $v_t$ to $v/4$."
|
||
},
|
||
{
|
||
"id": "69ac01c0-2ce2-4e6b-8fa2-be49cfb7fc6e",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Properties of Bulk Matter",
|
||
"subtopic": "Surface Tension and Capillarity",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Water rises to a height $h$ in a capillary tube. If the same water and another capillary tube of twice the radius are used, the height of rise becomes:",
|
||
"options": {
|
||
"A": "$\\dfrac{h}{2}$",
|
||
"B": "$\\dfrac{h}{4}$",
|
||
"C": "$4h$",
|
||
"D": "$2h$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Capillary rise $h=\\dfrac{2S\\cos\\theta}{\\rho g r}\\propto \\dfrac{1}{r}$. Doubling the radius halves the height of rise."
|
||
},
|
||
{
|
||
"id": "da7c340f-7b54-4a78-a695-17772e81427f",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Thermal Properties of Matter",
|
||
"subtopic": "Calorimetry",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "$100$ g of water at $100^\\circ$C is mixed with $300$ g of water at $20^\\circ$C in a calorimeter of negligible heat capacity. Neglecting heat losses, the final temperature of the mixture is:",
|
||
"options": {
|
||
"A": "$60^\\circ$C",
|
||
"B": "$55^\\circ$C",
|
||
"C": "$40^\\circ$C",
|
||
"D": "$45^\\circ$C"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Heat lost = heat gained: $0.1(100-\\theta)=0.3(\\theta-20)\\Rightarrow 10-0.1\\theta=0.3\\theta-6\\Rightarrow \\theta=40^\\circ$C."
|
||
},
|
||
{
|
||
"id": "d7611d1b-2724-4101-9bae-11dcb79fc107",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Thermodynamics",
|
||
"subtopic": "Isothermal Process",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "One mole of an ideal gas expands isothermally at $300$ K from a volume of $1$ L to $2$ L. The work done by the gas is ($R = 8.3\\ \\text{J mol}^{-1}\\text{K}^{-1}$, $\\ln 2 = 0.693$):",
|
||
"options": {
|
||
"A": "$1.7$ kJ",
|
||
"B": "$1.2$ kJ",
|
||
"C": "$0.9$ kJ",
|
||
"D": "$2.5$ kJ"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Work done in isothermal expansion $W=nRT\\ln\\dfrac{V_2}{V_1}=1\\times 8.3\\times 300\\times 0.693\\approx 1725$ J $\\approx 1.7$ kJ."
|
||
},
|
||
{
|
||
"id": "282b5cf7-6b7c-4e4e-9ca1-6c92f553f8b6",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Kinetic Theory of Gases",
|
||
"subtopic": "RMS Speed",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "At the same temperature, the ratio of the rms speed of hydrogen molecules to that of oxygen molecules is:",
|
||
"options": {
|
||
"A": "$4$",
|
||
"B": "$16$",
|
||
"C": "$\\dfrac{1}{4}$",
|
||
"D": "$\\dfrac{1}{16}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$v_{rms}=\\sqrt{\\dfrac{3RT}{M}}\\propto \\dfrac{1}{\\sqrt{M}}$. So $\\dfrac{v_{H_2}}{v_{O_2}}=\\sqrt{\\dfrac{M_{O_2}}{M_{H_2}}}=\\sqrt{\\dfrac{32}{2}}=4$."
|
||
},
|
||
{
|
||
"id": "c87340a2-f52b-49eb-afca-c9af7931c0ac",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Oscillations",
|
||
"subtopic": "Energy in SHM",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A particle executes SHM of amplitude $A$. When its displacement is $A/2$, the ratio of its kinetic energy to the total energy is:",
|
||
"options": {
|
||
"A": "$\\dfrac{1}{2}$",
|
||
"B": "$\\dfrac{3}{4}$",
|
||
"C": "$\\dfrac{1}{4}$",
|
||
"D": "$\\dfrac{4}{3}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$U=\\frac{1}{2}kx^2=\\frac{1}{4}(\\frac{1}{2}kA^2)$, so $KE=E-U=\\frac{3}{4}E$. Hence $KE/TE=3/4$."
|
||
},
|
||
{
|
||
"id": "3cd36cd6-761c-4f6a-b386-c5fb115cafab",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Oscillations",
|
||
"subtopic": "Spring-Mass Systems",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A block of mass $m$ oscillates with period $T$ when hung from a single spring. If two identical springs (each of the same stiffness) are attached in parallel and the same block is hung from the combination, the new period is:",
|
||
"options": {
|
||
"A": "$2T$",
|
||
"B": "$\\sqrt{2}\\,T$",
|
||
"C": "$\\dfrac{T}{\\sqrt{2}}$",
|
||
"D": "$\\dfrac{T}{2}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "In parallel, $k_{eq}=2k$ and $T=2\\pi\\sqrt{m/k_{eq}}\\propto 1/\\sqrt{k}$. So $T' = T/\\sqrt{2}$."
|
||
},
|
||
{
|
||
"id": "4520f79e-77d0-4883-a2e5-810880876ef6",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Waves",
|
||
"subtopic": "Beats",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A tuning fork of unknown frequency produces $6$ beats per second with another fork of frequency $512$ Hz. When a little wax is loaded on the unknown fork, the beat frequency decreases to $4$ beats per second. The frequency of the unknown fork is:",
|
||
"options": {
|
||
"A": "$506$ Hz",
|
||
"B": "$518$ Hz",
|
||
"C": "$524$ Hz",
|
||
"D": "$512$ Hz"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Unknown fork frequency $=512\\pm 6$, i.e. $506$ or $518$ Hz. Loading wax lowers the frequency. Since the beat frequency decreases (from 6 to 4), the unknown fork must have been above 512 Hz: it drops to $516$ Hz ($=512+4$), so the original frequency was $518$ Hz."
|
||
},
|
||
{
|
||
"id": "6b4455c5-503d-4600-9535-175fb3d38589",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Waves",
|
||
"subtopic": "Travelling Wave Equation",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The displacement of a particle of a travelling wave is given by $y = 0.05\\sin 2\\pi\\left(4t - \\dfrac{x}{8}\\right)$, where $y$ and $x$ are in metres and $t$ in seconds. The speed of the wave is:",
|
||
"options": {
|
||
"A": "$16\\ \\text{m s}^{-1}$",
|
||
"B": "$8\\ \\text{m s}^{-1}$",
|
||
"C": "$4\\ \\text{m s}^{-1}$",
|
||
"D": "$32\\ \\text{m s}^{-1}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Comparing with $y=A\\sin(\\omega t-kx)$: $\\omega = 8\\pi$, $k=\\dfrac{2\\pi}{8}$. Wave speed $v=\\dfrac{\\omega}{k}=\\dfrac{8\\pi}{2\\pi/8}=32\\ \\text{m s}^{-1}$."
|
||
},
|
||
{
|
||
"id": "3eed4dc6-2834-4e15-9e7b-f6c86f9a1d2c",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Electrostatics",
|
||
"subtopic": "Electric Dipole in Uniform Field",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "An electric dipole of moment $4\\times 10^{-5}$ C m is placed in a uniform electric field of $5\\times 10^{4}$ N C$^{-1}$. The maximum torque experienced by the dipole is:",
|
||
"options": {
|
||
"A": "$2$ N m",
|
||
"B": "$0.5$ N m",
|
||
"C": "$4$ N m",
|
||
"D": "$1$ N m"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Torque $\\tau=pE\\sin\\theta$ is maximum when $\\theta=90^\\circ$: $\\tau_{max}=pE=4\\times 10^{-5}\\times 5\\times 10^{4}=2$ N m."
|
||
},
|
||
{
|
||
"id": "a201b8e3-a5a8-40dc-b856-080bb40b3e8a",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Electrostatics",
|
||
"subtopic": "Combination of Capacitors",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A $2\\ \\mu$F and a $3\\ \\mu$F capacitor are connected in series across a $10$ V battery. The magnitude of charge on each capacitor is:",
|
||
"options": {
|
||
"A": "$30\\ \\mu$C",
|
||
"B": "$10\\ \\mu$C",
|
||
"C": "$12\\ \\mu$C",
|
||
"D": "$20\\ \\mu$C"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "$C_{eq}=\\dfrac{2\\times 3}{2+3}=1.2\\ \\mu$F. In series, each capacitor carries the same charge $q=C_{eq}V=1.2\\times 10=12\\ \\mu$C."
|
||
},
|
||
{
|
||
"id": "aafb1a10-ec32-43e0-b8cb-9742a5223790",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Current Electricity",
|
||
"subtopic": "Potentiometer",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In a potentiometer, a cell of emf $1.5$ V gives a null point at a length of $200$ cm. If another cell gives the null point at $160$ cm, its emf is:",
|
||
"options": {
|
||
"A": "$1.2$ V",
|
||
"B": "$1.6$ V",
|
||
"C": "$1.35$ V",
|
||
"D": "$1.0$ V"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "For a potentiometer, $E\\propto l$ (balanced length). So $E_2=E_1\\dfrac{l_2}{l_1}=1.5\\times\\dfrac{160}{200}=1.2$ V."
|
||
},
|
||
{
|
||
"id": "302c6fb3-d307-443e-8db2-c55159f66994",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Current Electricity",
|
||
"subtopic": "Galvanometer as Ammeter",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A galvanometer of resistance $99\\ \\Omega$ gives full-scale deflection for a current of $1$ mA. To convert it into an ammeter reading up to $1$ A, the shunt resistance required is nearly:",
|
||
"options": {
|
||
"A": "$0.01\\ \\Omega$",
|
||
"B": "$1\\ \\Omega$",
|
||
"C": "$0.1\\ \\Omega$",
|
||
"D": "$10\\ \\Omega$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "$S=\\dfrac{I_g G}{I-I_g}=\\dfrac{10^{-3}\\times 99}{0.999}\\approx 0.099\\approx 0.1\\ \\Omega$."
|
||
},
|
||
{
|
||
"id": "30a7478e-d05f-4dca-8daa-4c0a06b99aa0",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Moving Charges and Magnetism",
|
||
"subtopic": "Motion of Charge in Magnetic Field",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A proton enters a uniform magnetic field of $0.5$ T perpendicularly with a speed of $4\\times 10^{6}\\ \\text{m s}^{-1}$. The radius of its circular path is ($m_p = 1.67\\times 10^{-27}$ kg, $e = 1.6\\times 10^{-19}$ C):",
|
||
"options": {
|
||
"A": "$8.4$ cm",
|
||
"B": "$4.2$ cm",
|
||
"C": "$25.0$ cm",
|
||
"D": "$16.8$ cm"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$r=\\dfrac{mv}{qB}=\\dfrac{1.67\\times 10^{-27}\\times 4\\times 10^{6}}{1.6\\times 10^{-19}\\times 0.5}=0.0835$ m $\\approx 8.4$ cm."
|
||
},
|
||
{
|
||
"id": "dd162224-41f9-4d42-b60a-cbc141532727",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Moving Charges and Magnetism",
|
||
"subtopic": "Force Between Parallel Currents",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Two long straight parallel wires separated by $2$ cm carry currents of $5$ A each in the same direction. The force per unit length between them is ($\\mu_0 = 4\\pi\\times 10^{-7}\\ \\text{T m A}^{-1}$):",
|
||
"options": {
|
||
"A": "$1.25\\times 10^{-4}\\ \\text{N m}^{-1}$, attractive",
|
||
"B": "$2.5\\times 10^{-4}\\ \\text{N m}^{-1}$, attractive",
|
||
"C": "$5.0\\times 10^{-4}\\ \\text{N m}^{-1}$, repulsive",
|
||
"D": "$2.5\\times 10^{-4}\\ \\text{N m}^{-1}$, repulsive"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$\\dfrac{F}{l}=\\dfrac{\\mu_0 I_1 I_2}{2\\pi d}=\\dfrac{4\\pi\\times 10^{-7}\\times 25}{2\\pi\\times 0.02}=2.5\\times 10^{-4}\\ \\text{N m}^{-1}$. Parallel currents in the same direction attract."
|
||
},
|
||
{
|
||
"id": "a6dc29dd-dc14-4a54-bbb7-bbe4bb7afb3f",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Electromagnetic Induction",
|
||
"subtopic": "Motional EMF",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A metal rod of length $0.5$ m moves with a speed of $10\\ \\text{m s}^{-1}$ perpendicular to a uniform magnetic field of $0.2$ T. The emf induced between the ends of the rod is:",
|
||
"options": {
|
||
"A": "$5$ V",
|
||
"B": "$1$ V",
|
||
"C": "$2$ V",
|
||
"D": "$0.5$ V"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$\\varepsilon = Blv = 0.2\\times 0.5\\times 10 = 1$ V (Faraday's law of induction for a moving conductor)."
|
||
},
|
||
{
|
||
"id": "f7568b17-7fa3-42cb-9ca7-65a368127fca",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Alternating Current",
|
||
"subtopic": "Series LCR Resonance",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A series LCR circuit with $R = 40\\ \\Omega$ is connected to a $200$ V (rms) variable-frequency source. At resonance, the rms current in the circuit is:",
|
||
"options": {
|
||
"A": "$10$ A",
|
||
"B": "$2.5$ A",
|
||
"C": "$5$ A",
|
||
"D": "$4$ A"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "At resonance $X_L=X_C$, so the impedance is minimum and equals $R$: $I_{rms}=V/R=200/40=5$ A."
|
||
},
|
||
{
|
||
"id": "ababe2d0-a9fb-4627-bbaf-f5d4373e3b3b",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Alternating Current",
|
||
"subtopic": "rms and Peak Values",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The domestic power supply in India is rated $220$ V (rms). The peak value of this alternating voltage is nearly:",
|
||
"options": {
|
||
"A": "$440$ V",
|
||
"B": "$311$ V",
|
||
"C": "$156$ V",
|
||
"D": "$220$ V"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$V_0=\\sqrt{2}\\,V_{rms}=1.414\\times 220\\approx 311$ V."
|
||
},
|
||
{
|
||
"id": "bc627693-8db9-4282-9fca-56dfd18df4b4",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Electromagnetic Waves",
|
||
"subtopic": "Electromagnetic Spectrum",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following gives the correct order of increasing wavelength of the electromagnetic radiations?",
|
||
"options": {
|
||
"A": "Microwaves $<$ Ultraviolet $<$ X-rays $<$ Gamma rays",
|
||
"B": "Gamma rays $<$ X-rays $<$ Ultraviolet $<$ Microwaves",
|
||
"C": "Ultraviolet $<$ Gamma rays $<$ X-rays $<$ Microwaves",
|
||
"D": "X-rays $<$ Gamma rays $<$ Microwaves $<$ Ultraviolet"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "In the electromagnetic spectrum, frequency decreases (wavelength increases) in the order: $\\gamma$-rays $>$ X-rays $>$ UV $>$ visible $>$ IR $>$ microwaves. Hence increasing wavelength: $\\gamma$-rays $<$ X-rays $<$ UV $<$ microwaves."
|
||
},
|
||
{
|
||
"id": "a8c9aa50-8f0a-4980-a158-847868867159",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Ray Optics and Optical Instruments",
|
||
"subtopic": "Total Internal Reflection",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The critical angle for a medium with respect to air (vacuum) is $45^\\circ$. The refractive index of the medium is:",
|
||
"options": {
|
||
"A": "$1.41$",
|
||
"B": "$1.60$",
|
||
"C": "$1.50$",
|
||
"D": "$1.33$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$\\sin C = \\dfrac{1}{\\mu} \\Rightarrow \\mu = \\dfrac{1}{\\sin 45^\\circ}=\\sqrt{2}\\approx 1.41$."
|
||
},
|
||
{
|
||
"id": "8a7d563e-9566-4a6f-aaaf-1f8ec54d4314",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Ray Optics and Optical Instruments",
|
||
"subtopic": "Apparent Depth",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A bird is flying $12$ m above the surface of a lake and a fish is at a depth of $4$ m below the surface, directly below the bird. If the refractive index of water is $4/3$, the distance of the fish as observed by the bird is:",
|
||
"options": {
|
||
"A": "$16$ m",
|
||
"B": "$15$ m",
|
||
"C": "$21$ m",
|
||
"D": "$13$ m"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Looking from air into water, apparent depth $=\\dfrac{\\text{real depth}}{\\mu}=\\dfrac{4}{4/3}=3$ m. So the fish appears $(12+3)=15$ m away from the bird."
|
||
},
|
||
{
|
||
"id": "d65c2b9d-21f6-4796-9688-95b228b8b3fa",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Ray Optics and Optical Instruments",
|
||
"subtopic": "Simple Microscope",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A simple microscope uses a convex lens of focal length $5$ cm. If the near point of the eye is $25$ cm, the magnifying power at the near point (image at $D$) is:",
|
||
"options": {
|
||
"A": "$30$",
|
||
"B": "$25$",
|
||
"C": "$5$",
|
||
"D": "$6$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "For image at the near point, $M=1+\\dfrac{D}{f}=1+\\dfrac{25}{5}=6$."
|
||
},
|
||
{
|
||
"id": "b65be7be-46c9-431c-a7ce-fa543352c5a6",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Wave Optics",
|
||
"subtopic": "Polarisation",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Unpolarised light is incident from air on a plane glass surface of refractive index $1.5$. The angle of incidence for which the reflected light is completely plane polarised (Brewster angle) is nearly:",
|
||
"options": {
|
||
"A": "$63.4^\\circ$",
|
||
"B": "$45^\\circ$",
|
||
"C": "$56.3^\\circ$",
|
||
"D": "$33.7^\\circ$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Brewster's law: $\\mu=\\tan i_p \\Rightarrow i_p=\\tan^{-1}(1.5)\\approx 56.3^\\circ$."
|
||
},
|
||
{
|
||
"id": "7290f28b-bcfc-436b-ac73-b93451c14ee2",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Dual Nature of Radiation and Matter",
|
||
"subtopic": "Photoelectric Effect",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Light of wavelength $310$ nm is incident on a metal of work function $2$ eV. The maximum kinetic energy of the emitted photoelectrons is ($hc = 1240$ eV nm):",
|
||
"options": {
|
||
"A": "$6$ eV",
|
||
"B": "$4$ eV",
|
||
"C": "$2$ eV",
|
||
"D": "$1$ eV"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Photon energy $E=\\dfrac{1240}{310}=4$ eV. $KE_{max}=E-\\phi=4-2=2$ eV."
|
||
},
|
||
{
|
||
"id": "e3a9afd9-e086-4493-b93a-4fec2df6d4bf",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Atoms",
|
||
"subtopic": "Bohr Model of Hydrogen Atom",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In the hydrogen atom, the energy released when an electron jumps from the $n=2$ orbit to the $n=1$ orbit is:",
|
||
"options": {
|
||
"A": "$12.1$ eV",
|
||
"B": "$10.2$ eV",
|
||
"C": "$3.4$ eV",
|
||
"D": "$13.6$ eV"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$E_n=-\\dfrac{13.6}{n^2}$ eV. $\\Delta E=13.6\\left(1-\\dfrac{1}{4}\\right)=13.6\\times\\dfrac{3}{4}=10.2$ eV."
|
||
},
|
||
{
|
||
"id": "80421dc1-ac66-4a35-931d-92dec73943fa",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Nuclei",
|
||
"subtopic": "Mass-Energy and Nuclear Binding Energy",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The mass of a $\\prescript{14}{7}{}$N nucleus is $14.00307$ u, while the masses of a proton and a neutron are $1.00783$ u and $1.00867$ u respectively. The binding energy per nucleon of $\\prescript{14}{7}{}$N is nearly ($1$ u $= 931.5$ MeV/$c^2$):",
|
||
"options": {
|
||
"A": "$5.5$ MeV",
|
||
"B": "$7.5$ MeV",
|
||
"C": "$6.5$ MeV",
|
||
"D": "$8.5$ MeV"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Mass of 7p + 7n $=7(1.00783+1.00867)=14.1155$ u. Mass defect $\\Delta m = 14.1155-14.00307=0.11243$ u. Total BE $=0.11243\\times 931.5\\approx 104.7$ MeV. Per nucleon $=104.7/14\\approx 7.5$ MeV."
|
||
},
|
||
{
|
||
"id": "6dc193d4-6a98-4d29-a322-efa371278406",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Nuclei",
|
||
"subtopic": "Radioactive Decay Law",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The activity of a radioactive sample falls to one-fourth of its initial value in $20$ days. The half-life of the sample is:",
|
||
"options": {
|
||
"A": "$5$ days",
|
||
"B": "$10$ days",
|
||
"C": "$40$ days",
|
||
"D": "$20$ days"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$N/N_0=1/4=(1/2)^2$, i.e. two half-lives elapse in 20 days. $T_{1/2}=20/2=10$ days."
|
||
},
|
||
{
|
||
"id": "33e3b9a8-957c-4cb7-be91-a3a840eb2e36",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Semiconductor Electronics",
|
||
"subtopic": "Transistor as Amplifier",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In a common-emitter transistor amplifier, the emitter current is $5.0$ mA and the base current is $0.10$ mA. The current amplification factor $\\beta$ is:",
|
||
"options": {
|
||
"A": "$9$",
|
||
"B": "$51$",
|
||
"C": "$50$",
|
||
"D": "$49$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "$I_C=I_E-I_B=4.9$ mA. $\\beta=\\dfrac{I_C}{I_B}=\\dfrac{4.9}{0.10}=49$."
|
||
},
|
||
{
|
||
"id": "fcfa5196-6630-46ba-b5e3-3da0bf97d9c2",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Semiconductor Electronics",
|
||
"subtopic": "Special Purpose Diodes",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A photodiode is normally operated in:",
|
||
"options": {
|
||
"A": "forward bias with high current",
|
||
"B": "unbiased condition",
|
||
"C": "reverse bias, with illumination on the junction",
|
||
"D": "forward bias with no illumination"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "In reverse bias, the reverse saturation current of a photodiode is proportional to the intensity of incident light, making it a sensitive light detector (used in reverse bias with the junction illuminated)."
|
||
},
|
||
{
|
||
"id": "5f3f38c3-540f-40c2-98d9-4f9301a3fbd0",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Experimental Skills",
|
||
"subtopic": "Screw Gauge",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The pitch of a screw gauge is $0.5$ mm and the head scale has $50$ divisions. The main scale reads $3.5$ mm and the circular scale reads $27$ divisions when a wire is placed between the jaws. The diameter of the wire is:",
|
||
"options": {
|
||
"A": "$3.27$ mm",
|
||
"B": "$3.77$ mm",
|
||
"C": "$3.87$ mm",
|
||
"D": "$3.67$ mm"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Least count $=\\dfrac{0.5}{50}=0.01$ mm. Reading $=$ MSR $+$ LC $\\times$ CSR $=3.5+27\\times 0.01=3.77$ mm."
|
||
},
|
||
{
|
||
"id": "64a87680-f6d2-40d0-88f3-3d108a66e9ad",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Units and Measurements",
|
||
"subtopic": "Errors in Measurement",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The percentage errors in the measurement of mass and volume of a metal block are $2\\%$ and $3\\%$ respectively. The maximum percentage error in the calculated density is:",
|
||
"options": {
|
||
"A": "$6\\%$",
|
||
"B": "$3\\%$",
|
||
"C": "$5\\%$",
|
||
"D": "$1\\%$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "$\\rho = m/V$, so $\\dfrac{\\Delta\\rho}{\\rho}=\\dfrac{\\Delta m}{m}+\\dfrac{\\Delta V}{V}=2\\%+3\\%=5\\%$."
|
||
},
|
||
{
|
||
"id": "626b1ab2-1ee9-4c14-a696-12a8df838c6a",
|
||
"section": "General",
|
||
"subject": "Physics",
|
||
"topic": "Mechanical Properties of Solids",
|
||
"subtopic": "Young's Modulus",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Two wires $A$ and $B$ of the same material, same length and radii in the ratio $2:1$ are suspended from the ceiling and loaded with the same weight. The ratio of elongation of $A$ to that of $B$ is:",
|
||
"options": {
|
||
"A": "$4:1$",
|
||
"B": "$1:4$",
|
||
"C": "$1:2$",
|
||
"D": "$2:1$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$\\Delta l=\\dfrac{FL}{\\pi r^2 Y}\\propto \\dfrac{1}{r^2}$. With $r_A:r_B=2:1$, $\\Delta l_A:\\Delta l_B=1:4$."
|
||
},
|
||
{
|
||
"id": "f29e87b7-d0ee-4e79-805f-3b5da2b29913",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Some Basic Concepts of Chemistry",
|
||
"subtopic": "Mole Concept",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The total number of atoms present in $4.25$ g of $NH_3$ is approximately ($N_A = 6.02\\times 10^{23}\\ \\text{mol}^{-1}$):",
|
||
"options": {
|
||
"A": "$3.01\\times 10^{23}$",
|
||
"B": "$1.5\\times 10^{23}$",
|
||
"C": "$6.02\\times 10^{23}$",
|
||
"D": "$1.2\\times 10^{24}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Moles of $NH_3 = 4.25/17 = 0.25$ mol. Each molecule has 4 atoms, so atoms $=0.25\\times 4\\times N_A = N_A \\approx 6.02\\times 10^{23}$."
|
||
},
|
||
{
|
||
"id": "7fe48721-16ce-4b0a-8ae7-2e7697d06188",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Structure of Atom",
|
||
"subtopic": "Quantum Numbers",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following sets of quantum numbers is NOT permissible for an electron in an atom?",
|
||
"options": {
|
||
"A": "$n=3,\\ l=2,\\ m=-2,\\ s=+\\frac{1}{2}$",
|
||
"B": "$n=4,\\ l=0,\\ m=0,\\ s=-\\frac{1}{2}$",
|
||
"C": "$n=3,\\ l=2,\\ m=-3,\\ s=-\\frac{1}{2}$",
|
||
"D": "$n=2,\\ l=1,\\ m=0,\\ s=+\\frac{1}{2}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "For a given $l$, $m$ can take values $-l$ to $+l$. For $l=2$, $m=-3$ is not allowed (only $-2$ to $+2$); all other sets are valid."
|
||
},
|
||
{
|
||
"id": "3ef23036-0a59-4f7f-a089-44e6d255122b",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Structure of Atom",
|
||
"subtopic": "de Broglie Hypothesis",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The wavelength associated with an electron accelerated through a potential difference of $100$ V is ($h = 6.63\\times 10^{-34}$ J s, $m_e = 9.1\\times 10^{-31}$ kg, $e = 1.6\\times 10^{-19}$ C):",
|
||
"options": {
|
||
"A": "$12.27\\ \\text{nm}$",
|
||
"B": "$0.01227\\ \\text{nm}$",
|
||
"C": "$1.227\\ \\text{nm}$",
|
||
"D": "$0.1227\\ \\text{nm}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "$\\lambda = \\dfrac{h}{\\sqrt{2meV}} = \\dfrac{12.27}{\\sqrt{V}}\\ \\text{Å} = \\dfrac{12.27}{\\sqrt{100}} = 1.227\\ \\text{Å} = 0.1227\\ \\text{nm}$."
|
||
},
|
||
{
|
||
"id": "72789dce-5db6-442d-92c9-359c3b1bdf20",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Classification of Elements and Periodicity",
|
||
"subtopic": "Ionization Enthalpy",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The correct order of first ionization enthalpy of N, O and F is:",
|
||
"options": {
|
||
"A": "$N < F < O$",
|
||
"B": "$F < O < N$",
|
||
"C": "$N < O < F$",
|
||
"D": "$O < N < F$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Across a period IE increases, but N (configuration $2s^2 2p^3$) has extra stable half-filled $p$ orbitals, so $IE_1(O) < IE_1(N)$. F has the highest IE: $O < N < F$."
|
||
},
|
||
{
|
||
"id": "5a197e12-4926-42f4-bac2-cdbb2bd7c032",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Classification of Elements and Periodicity",
|
||
"subtopic": "Ionic Radii",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The correct order of ionic radii among the isoelectronic species $N^{3-}$, $O^{2-}$, $F^-$, $Na^+$ and $Mg^{2+}$ is:",
|
||
"options": {
|
||
"A": "$N^{3-} > O^{2-} > F^- > Na^+ > Mg^{2+}$",
|
||
"B": "$N^{3-} > Na^+ > O^{2-} > F^- > Mg^{2+}$",
|
||
"C": "$F^- > O^{2-} > N^{3-} > Mg^{2+} > Na^+$",
|
||
"D": "$Mg^{2+} > Na^+ > F^- > O^{2-} > N^{3-}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "All have 10 electrons, so size depends only on nuclear charge. Higher $Z$ pulls the electron cloud closer: $N^{3-} (Z=7) > O^{2-} (8) > F^- (9) > Na^+ (11) > Mg^{2+} (12)$."
|
||
},
|
||
{
|
||
"id": "1abc1aa4-ca10-4286-869e-4c0ecbe48cfd",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Chemical Bonding and Molecular Structure",
|
||
"subtopic": "Hybridisation",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The hybridisation of the sulphur atom and the shape of the $SF_4$ molecule are respectively:",
|
||
"options": {
|
||
"A": "$sp^3d$, trigonal bipyramidal",
|
||
"B": "$sp^3d$, see-saw",
|
||
"C": "$sp^3d^2$, square planar",
|
||
"D": "$sp^3$, tetrahedral"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$S$ has 4 bond pairs + 1 lone pair (5 electron pairs) $\\Rightarrow sp^3d$. With one equatorial lone pair, the shape is see-saw."
|
||
},
|
||
{
|
||
"id": "6a12454e-efc7-4a1e-87c4-3cddfd1d4787",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Chemical Bonding and Molecular Structure",
|
||
"subtopic": "Dipole Moment",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following molecules has zero dipole moment?",
|
||
"options": {
|
||
"A": "$H_2O$",
|
||
"B": "$SO_2$",
|
||
"C": "$NH_3$",
|
||
"D": "$CO_2$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "$CO_2$ is linear ($O=C=O$); the two equal C=O bond dipoles point opposite and cancel. $H_2O$, $NH_3$ and $SO_2$ are bent/pyramidal and possess net dipole moments."
|
||
},
|
||
{
|
||
"id": "2487a207-a004-4556-a2ce-ff37bab63b85",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Chemical Bonding and Molecular Structure",
|
||
"subtopic": "Molecular Orbital Theory",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "According to molecular orbital theory, the bond order of the $O_2^-$ (superoxide) ion is:",
|
||
"options": {
|
||
"A": "$1.5$",
|
||
"B": "$2$",
|
||
"C": "$1$",
|
||
"D": "$2.5$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$O_2^-$ has 17 electrons: bonding electrons $=10$, antibonding $=7$. Bond order $=\\dfrac{10-7}{2}=1.5$; it is paramagnetic with one unpaired electron."
|
||
},
|
||
{
|
||
"id": "9c00cfa4-f4e6-454b-b825-a34cfaa074da",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Chemical Bonding and Molecular Structure",
|
||
"subtopic": "VSEPR Theory",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The shape of the $XeF_4$ molecule is:",
|
||
"options": {
|
||
"A": "square planar",
|
||
"B": "octahedral",
|
||
"C": "tetrahedral",
|
||
"D": "see-saw"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$Xe$ has 4 bond pairs and 2 lone pairs ($sp^3d^2$). The lone pairs occupy opposite (trans) positions, giving a square planar shape."
|
||
},
|
||
{
|
||
"id": "064657aa-2397-4089-a5c1-108d3ba7baa6",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "States of Matter",
|
||
"subtopic": "Ideal Gas Equation",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The volume occupied by $4.4$ g of $CO_2$ at STP is ($C = 12$, $O = 16$):",
|
||
"options": {
|
||
"A": "$1.12$ L",
|
||
"B": "$4.48$ L",
|
||
"C": "$22.4$ L",
|
||
"D": "$2.24$ L"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Moles of $CO_2 = 4.4/44 = 0.1$ mol. At STP, 1 mol gas occupies $22.4$ L, so volume $= 0.1\\times 22.4 = 2.24$ L."
|
||
},
|
||
{
|
||
"id": "7f617a28-cfa4-4451-a2a9-c891a764c457",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Thermodynamics",
|
||
"subtopic": "Enthalpy and Internal Energy",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "For which of the following reactions is $\\Delta H$ greater than $\\Delta U$?",
|
||
"options": {
|
||
"A": "$H_2(g) + I_2(g) \\rightarrow 2HI(g)$",
|
||
"B": "$PCl_5(g) \\rightarrow PCl_3(g) + Cl_2(g)$",
|
||
"C": "$N_2(g) + 3H_2(g) \\rightarrow 2NH_3(g)$",
|
||
"D": "$2SO_2(g) + O_2(g) \\rightarrow 2SO_3(g)$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$\\Delta H = \\Delta U + \\Delta n_g RT$. Only in option D, $\\Delta n_g = +1$, so $\\Delta H > \\Delta U$. In A and B $\\Delta n_g < 0$ and in C $\\Delta n_g = 0$."
|
||
},
|
||
{
|
||
"id": "8073850e-a221-44be-9773-b8a6edae1306",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Thermodynamics",
|
||
"subtopic": "Gibbs Energy and Spontaneity",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A reaction is spontaneous at all temperatures when:",
|
||
"options": {
|
||
"A": "$\\Delta H < 0,\\ \\Delta S < 0$",
|
||
"B": "$\\Delta H > 0,\\ \\Delta S < 0$",
|
||
"C": "$\\Delta H < 0,\\ \\Delta S > 0$",
|
||
"D": "$\\Delta H > 0,\\ \\Delta S > 0$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "$\\Delta G = \\Delta H - T\\Delta S$. With $\\Delta H < 0$ and $\\Delta S > 0$, both terms are negative at every $T$, so $\\Delta G < 0$ always."
|
||
},
|
||
{
|
||
"id": "2f8e33a1-2afb-499f-bcad-62289d0e2ab9",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Equilibrium",
|
||
"subtopic": "Relation between Kp and Kc",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "For the equilibrium $N_2(g) + 3H_2(g) \\rightleftharpoons 2NH_3(g)$, the ratio $K_p/K_c$ is equal to:",
|
||
"options": {
|
||
"A": "$(RT)^{-2}$",
|
||
"B": "$1$",
|
||
"C": "$(RT)^2$",
|
||
"D": "$RT$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$K_p = K_c(RT)^{\\Delta n}$, where $\\Delta n = 2 - 4 = -2$. Hence $K_p/K_c = (RT)^{-2} = \\dfrac{1}{(RT)^2}$."
|
||
},
|
||
{
|
||
"id": "5b5f2686-bf54-4211-b782-a25f7a093b96",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Equilibrium",
|
||
"subtopic": "pH of Strong Base",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The pH of a $0.001$ M aqueous NaOH solution at $25^\\circ$C is:",
|
||
"options": {
|
||
"A": "$3$",
|
||
"B": "$11$",
|
||
"C": "$10$",
|
||
"D": "$12$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$[OH^-] = 10^{-3}$ M $\\Rightarrow pOH = 3$. Since $pH + pOH = 14$, $pH = 11$."
|
||
},
|
||
{
|
||
"id": "8a268478-ce8c-47fe-be6b-627b35b7fb3a",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Equilibrium",
|
||
"subtopic": "Le Chatelier's Principle",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "For the Haber process, $N_2(g) + 3H_2(g) \\rightleftharpoons 2NH_3(g)$, $\\Delta H = -92$ kJ mol$^{-1}$. Which change will increase the yield of $NH_3$ at equilibrium?",
|
||
"options": {
|
||
"A": "Increasing temperature",
|
||
"B": "Decreasing pressure",
|
||
"C": "Adding more $NH_3$ to the reaction mixture",
|
||
"D": "Increasing pressure at constant temperature"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "The forward reaction reduces the number of gaseous moles (4 $\\to$ 2) and is exothermic, so high pressure and low temperature favour $NH_3$. Increasing pressure shifts equilibrium forward; adding product or raising $T$ shifts it backward."
|
||
},
|
||
{
|
||
"id": "ac9ad180-18d2-4431-a3fc-9c1f0c615966",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Redox Reactions",
|
||
"subtopic": "Oxidation Number",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The oxidation state of chromium in the dichromate ion $Cr_2O_7^{2-}$ is:",
|
||
"options": {
|
||
"A": "$+7$",
|
||
"B": "$+6$",
|
||
"C": "$+3$",
|
||
"D": "$+4$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Let oxidation state of Cr be $x$: $2x + 7(-2) = -2 \\Rightarrow 2x = +12 \\Rightarrow x = +6$."
|
||
},
|
||
{
|
||
"id": "8bf9e506-d1be-4022-be7b-929516860cf0",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Redox Reactions",
|
||
"subtopic": "Equivalent Weight",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The equivalent weight of $KMnO_4$ (formula weight $= 158$) when it acts as an oxidising agent in acidic medium is:",
|
||
"options": {
|
||
"A": "$52.7$",
|
||
"B": "$158.0$",
|
||
"C": "$79.0$",
|
||
"D": "$31.6$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "In acidic medium $MnO_4^- \\to Mn^{2+}$ involves a 5-electron change. Equivalent weight $= \\dfrac{158}{5} = 31.6$."
|
||
},
|
||
{
|
||
"id": "35ba48ca-8ab3-46c9-8218-07b639a2597c",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Electrochemistry",
|
||
"subtopic": "Faraday's Laws of Electrolysis",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The quantity of charge required to deposit one mole of aluminium from molten $Al_2O_3$ is ($F = 96500$ C mol$^{-1}$):",
|
||
"options": {
|
||
"A": "$96500$ C",
|
||
"B": "$48250$ C",
|
||
"C": "$193000$ C",
|
||
"D": "$289500$ C"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "$Al^{3+} + 3e^- \\to Al$ needs 3 Faradays per mole: $q = 3\\times 96500 = 289500$ C."
|
||
},
|
||
{
|
||
"id": "22bb4e9c-4cb6-42ef-a6c9-e82c08afa733",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Solutions",
|
||
"subtopic": "Mole Fraction",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The mole fraction of glucose in a solution prepared by dissolving $18$ g of glucose in $90$ g of water is ($C = 12$, $H = 1$, $O = 16$):",
|
||
"options": {
|
||
"A": "$0.02$",
|
||
"B": "$0.05$",
|
||
"C": "$0.20$",
|
||
"D": "$0.10$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$n_{glucose} = 18/180 = 0.1$ mol; $n_{water} = 90/18 = 5$ mol. $x_{glucose} = \\dfrac{0.1}{5.1} \\approx 0.02$."
|
||
},
|
||
{
|
||
"id": "df3254ed-f76e-49fc-924f-949de5df027e",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Chemical Kinetics",
|
||
"subtopic": "First Order Reactions",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A first order reaction has a rate constant $k = 6.93\\times 10^{-3}\\ \\text{s}^{-1}$. Its half-life period is:",
|
||
"options": {
|
||
"A": "$200$ s",
|
||
"B": "$100$ s",
|
||
"C": "$693$ s",
|
||
"D": "$50$ s"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "For a first order reaction $t_{1/2} = \\dfrac{0.693}{k} = \\dfrac{0.693}{6.93\\times 10^{-3}} = 100$ s (independent of initial concentration)."
|
||
},
|
||
{
|
||
"id": "93cca283-7514-4299-bdb6-096f8bf97871",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Chemical Kinetics",
|
||
"subtopic": "Order of Reaction",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "For the reaction $A \\rightarrow$ products, the rate doubles when the concentration of $A$ is doubled, and becomes half when $[A]$ is halved. The order of the reaction with respect to $A$ is:",
|
||
"options": {
|
||
"A": "$2$",
|
||
"B": "$0$",
|
||
"C": "$1$",
|
||
"D": "$3$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Rate $= k[A]^n$; doubling $[A]$ doubles the rate only when $n = 1$. So the reaction is first order in $A$."
|
||
},
|
||
{
|
||
"id": "2d01527c-c425-4dfd-9e05-1213fdf70345",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Chemical Kinetics",
|
||
"subtopic": "Arrhenius Equation",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The rate of a reaction doubles when temperature is raised from $300$ K to $310$ K. The activation energy of the reaction is ($R = 8.3\\ \\text{J K}^{-1}\\text{mol}^{-1}$, $\\log 2 = 0.301$):",
|
||
"options": {
|
||
"A": "$41.9\\ \\text{kJ mol}^{-1}$",
|
||
"B": "$26.8\\ \\text{kJ mol}^{-1}$",
|
||
"C": "$107.2\\ \\text{kJ mol}^{-1}$",
|
||
"D": "$53.6\\ \\text{kJ mol}^{-1}$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "$\\log\\dfrac{k_2}{k_1} = \\dfrac{E_a}{2.303R}\\cdot\\dfrac{T_2-T_1}{T_1T_2}$: $0.301 = \\dfrac{E_a}{2.303\\times 8.3}\\times\\dfrac{10}{300\\times 310}$ $\\Rightarrow E_a \\approx 2.303\\times 8.3\\times 0.301\\times 9300 \\approx 53.6\\ \\text{kJ mol}^{-1}$."
|
||
},
|
||
{
|
||
"id": "fffefc2e-4019-4055-ba93-07516cc66931",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "p-Block Elements",
|
||
"subtopic": "Compounds of Sulphur",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The bleaching action of sulphur dioxide is due to its:",
|
||
"options": {
|
||
"A": "reducing nature and is permanent",
|
||
"B": "reducing nature and is temporary",
|
||
"C": "oxidising nature and is temporary",
|
||
"D": "oxidising nature and is permanent"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$SO_2$ bleaches by reduction: $SO_2 + 2H_2O \\to H_2SO_4 + 2[H]$, and the nascent hydrogen reduces the coloured dye to a colourless product. The colour is often restored by air oxidation, so the bleach is temporary (unlike $Cl_2$, which bleaches by oxidation)."
|
||
},
|
||
{
|
||
"id": "ec9695df-48d5-4cb7-8219-aaee31af1426",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "p-Block Elements",
|
||
"subtopic": "Oxoacids of Phosphorus",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The basicity of phosphorous acid, $H_3PO_3$, is:",
|
||
"options": {
|
||
"A": "$3$",
|
||
"B": "$2$",
|
||
"C": "$4$",
|
||
"D": "$1$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$H_3PO_3$ has the structure $HPO(OH)_2$: only the two OH hydrogens are ionisable; the third H is bonded directly to P. Hence it is a diprotic (dibasic) acid."
|
||
},
|
||
{
|
||
"id": "b38718d9-6f37-46b8-9232-ce60bb187aca",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "p-Block Elements",
|
||
"subtopic": "Interhalogen and Polyhalide Ions",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The shape of the triiodide ion, $I_3^-$, is:",
|
||
"options": {
|
||
"A": "trigonal planar",
|
||
"B": "bent (V-shaped)",
|
||
"C": "T-shaped",
|
||
"D": "linear"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "The central iodine in $I_3^-$ is $sp^3d$ hybridised with 2 bond pairs and 3 lone pairs. The three lone pairs occupy equatorial positions, forcing the ion to be linear (like $XeF_2$)."
|
||
},
|
||
{
|
||
"id": "64344071-4463-4573-9e6d-4aef5c90a934",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "d- and f-Block Elements",
|
||
"subtopic": "Colour of Transition Metal Ions",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "$Cu^+$ is colourless in aqueous solution whereas $Cu^{2+}$ is blue. This is because:",
|
||
"options": {
|
||
"A": "$Cu^+$ has a completely filled $3d^{10}$ configuration and cannot undergo $d$-$d$ transitions",
|
||
"B": "$Cu^+$ has an incomplete $3d$ subshell",
|
||
"C": "$Cu^{2+}$ has a completely filled $3d^{10}$ configuration",
|
||
"D": "$Cu^{2+}$ ions are larger in size than $Cu^+$ ions"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$Cu^+$ is $3d^{10}$ (no unpaired $d$ electron, no $d$-$d$ transition), while $Cu^{2+}$ is $3d^9$ and absorbs visible light for $d$-$d$ transitions, appearing blue."
|
||
},
|
||
{
|
||
"id": "2f68f747-31da-4496-b17c-6c1870a7c0ba",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "d- and f-Block Elements",
|
||
"subtopic": "Oxidation States",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The highest oxidation state exhibited by manganese in its common compounds is:",
|
||
"options": {
|
||
"A": "$+6$",
|
||
"B": "$+4$",
|
||
"C": "$+5$",
|
||
"D": "$+7$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Mn ($3d^5 4s^2$) shows a maximum oxidation state of $+7$, e.g. in $KMnO_4$ and $Mn_2O_7$, corresponding to the total loss of all valence electrons."
|
||
},
|
||
{
|
||
"id": "539865ea-9f65-49a0-9a53-c1abaa290321",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "d- and f-Block Elements",
|
||
"subtopic": "Magnetic Properties",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The spin-only magnetic moment of $Fe^{3+}$ ($Z = 26$) is:",
|
||
"options": {
|
||
"A": "$5.92$ BM",
|
||
"B": "$4.90$ BM",
|
||
"C": "$6.93$ BM",
|
||
"D": "$3.87$ BM"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$Fe^{3+}$ is $3d^5$ with $n = 5$ unpaired electrons. $\\mu = \\sqrt{n(n+2)} = \\sqrt{35} = 5.92$ BM."
|
||
},
|
||
{
|
||
"id": "1cf6395f-fb0c-4201-923c-fea57567365b",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Coordination Compounds",
|
||
"subtopic": "Nomenclature of Coordination Compounds",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The IUPAC name of $[Co(NH_3)_5Cl]Cl_2$ is:",
|
||
"options": {
|
||
"A": "pentaamminechloridocobalt(II) chloride",
|
||
"B": "chloridopentaamminecobalt(III) dichloride",
|
||
"C": "pentaamminechloridocobalt(III) chloride",
|
||
"D": "pentachloroamminecobalt(III) chloride"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Ligands are named alphabetically (ammine before chlorido). The complex ion carries $+3$ on Co (2 Cl$^-$ outside + 1 Cl$^-$ inside), so the name is pentaamminechloridocobalt(III) chloride."
|
||
},
|
||
{
|
||
"id": "68254f5b-be8b-4107-862c-f151d02b9372",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Coordination Compounds",
|
||
"subtopic": "Ligands and Crystal Field Theory",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following ligands is a strong field ligand according to the spectrochemical series?",
|
||
"options": {
|
||
"A": "$H_2O$",
|
||
"B": "$CN^-$",
|
||
"C": "$F^-$",
|
||
"D": "$Cl^-$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "In the spectrochemical series, $CN^-$ lies far to the strong-field end ($I^- < Br^- < Cl^- < F^- < H_2O < NH_3 < en < CN^- \\approx CO$), causing large crystal field splitting."
|
||
},
|
||
{
|
||
"id": "e558ed22-7ceb-4aee-9ef3-d48555fd59f4",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Coordination Compounds",
|
||
"subtopic": "Isomerism in Coordination Compounds",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The number of geometrical isomers possible for the complex ion $[Co(NH_3)_4Cl_2]^+$ is:",
|
||
"options": {
|
||
"A": "$3$",
|
||
"B": "$4$",
|
||
"C": "$1$",
|
||
"D": "$2$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "An octahedral $MA_4B_2$ complex shows two geometrical isomers: cis (the two Cl adjacent) and trans (the two Cl opposite)."
|
||
},
|
||
{
|
||
"id": "6d2fd6ca-f975-4dc9-bfd6-84a71bc69d3c",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Coordination Compounds",
|
||
"subtopic": "Valence Bond Theory",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "$[Ni(CN)_4]^{2-}$ is diamagnetic and square planar, whereas $[NiCl_4]^{2-}$ is paramagnetic and tetrahedral. This is because:",
|
||
"options": {
|
||
"A": "$CN^-$ is a weak field ligand causing $sp^3$ hybridisation",
|
||
"B": "$CN^-$ is a strong field ligand that pairs the $d$ electrons of $Ni^{2+}$ leading to $dsp^2$ hybridisation",
|
||
"C": "$Ni^{2+}$ has a $3d^{10}$ configuration in both complexes",
|
||
"D": "$Cl^-$ is a strong field ligand that pairs all electrons"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "$Ni^{2+}$ is $3d^8$. $CN^-$ (strong field) pairs the two unpaired $d$ electrons giving $dsp^2$ square planar, diamagnetic $[Ni(CN)_4]^{2-}$; weak field $Cl^-$ leaves them unpaired ($sp^3$, tetrahedral, paramagnetic)."
|
||
},
|
||
{
|
||
"id": "1209147e-d322-4a50-9dca-20eb74b33daf",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Haloalkanes and Haloarenes",
|
||
"subtopic": "SN1 Reactions",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following alkyl halides undergoes hydrolysis by the $S_N1$ mechanism most readily?",
|
||
"options": {
|
||
"A": "$(CH_3)_2CHCl$",
|
||
"B": "$CH_3CH_2Cl$",
|
||
"C": "$(CH_3)_3CCl$",
|
||
"D": "$CH_3Cl$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "$S_N1$ rate depends on carbocation stability: tertiary $> $ secondary $>$ primary. $(CH_3)_3CCl$ forms the most stable tertiary carbocation, so it is most reactive."
|
||
},
|
||
{
|
||
"id": "1f37875b-c59a-4654-8783-f9046d1f7365",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Haloalkanes and Haloarenes",
|
||
"subtopic": "Reactivity of Halides",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Treatment of which of the following with aqueous KOH under $S_N1$ conditions gives the fastest reaction?",
|
||
"options": {
|
||
"A": "$CH_3CH_2Cl$",
|
||
"B": "chlorobenzene",
|
||
"C": "$CH_3Cl$",
|
||
"D": "$C_6H_5CH_2Cl$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Benzyl chloride ionises to the benzyl carbocation, which is resonance stabilised by the phenyl ring, so benzyl chloride reacts fastest among the given halides. Chlorobenzene is least reactive (partial double-bond character of C–Cl)."
|
||
},
|
||
{
|
||
"id": "cf6807a7-0d93-49c4-95a2-18d697104f8a",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Alcohols, Phenols and Ethers",
|
||
"subtopic": "Lucas Test",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In the Lucas test, an alcohol gives turbidity immediately at room temperature. The alcohol is most likely:",
|
||
"options": {
|
||
"A": "a secondary alcohol",
|
||
"B": "a tertiary alcohol",
|
||
"C": "a primary alcohol",
|
||
"D": "phenol"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "With conc. HCl and anhydrous $ZnCl_2$ (Lucas reagent), tertiary alcohols form insoluble alkyl chlorides immediately; secondary alcohols take about 5 minutes and primary alcohols do not react at room temperature."
|
||
},
|
||
{
|
||
"id": "e6d6b0a9-304e-493c-bf41-861f98670d89",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Alcohols, Phenols and Ethers",
|
||
"subtopic": "Acidity of Phenols",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following is the most acidic?",
|
||
"options": {
|
||
"A": "$p$-nitrophenol",
|
||
"B": "phenol",
|
||
"C": "$p$-cresol",
|
||
"D": "ethanol"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "The $-NO_2$ group is strongly electron-withdrawing (–I and –R effects), which stabilises the $p$-nitrophenoxide ion; hence $p$-nitrophenol is more acidic than phenol, $p$-cresol or ethanol."
|
||
},
|
||
{
|
||
"id": "d9a8e8c5-bbdf-42e0-9f9d-241663ea2d58",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Aldehydes, Ketones and Carboxylic Acids",
|
||
"subtopic": "Tollens' Test",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following compounds gives a positive Tollens' test (silver mirror)?",
|
||
"options": {
|
||
"A": "acetaldehyde",
|
||
"B": "acetone",
|
||
"C": "diethyl ether",
|
||
"D": "benzophenone"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Tollens' reagent (ammoniacal $AgNO_3$) oxidises aldehydes but not ketones or ethers. Acetaldehyde reduces $Ag^+$ to metallic silver, forming a silver mirror."
|
||
},
|
||
{
|
||
"id": "50deecb0-ddec-42cf-9d4a-92e4f06bb02c",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Aldehydes, Ketones and Carboxylic Acids",
|
||
"subtopic": "Cannizzaro Reaction",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following undergoes the Cannizzaro reaction with concentrated alkali?",
|
||
"options": {
|
||
"A": "$CH_3CH_2CHO$",
|
||
"B": "$CH_3COCH_3$",
|
||
"C": "$HCHO$",
|
||
"D": "$CH_3CHO$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "The Cannizzaro (disproportionation) reaction is given by aldehydes lacking $\\alpha$-hydrogen. $HCHO$ has no $\\alpha$-carbon, so it gives methanol and sodium formate with conc. NaOH; the others have $\\alpha$-H and undergo aldol condensation."
|
||
},
|
||
{
|
||
"id": "ae4fec35-7200-430e-aa3d-593e298017d4",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Aldehydes, Ketones and Carboxylic Acids",
|
||
"subtopic": "Hell-Volhard-Zelinsky Reaction",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Alpha-halogenation of a carboxylic acid containing an $\\alpha$-hydrogen is carried out using:",
|
||
"options": {
|
||
"A": "$KMnO_4$ and $HCl$",
|
||
"B": "$Cl_2$ in presence of red phosphorus",
|
||
"C": "$Cl_2$ in presence of ultraviolet light only",
|
||
"D": "$LiAlH_4$ followed by $Cl_2$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "In the Hell-Volhard-Zelinsky reaction, $Cl_2$ (or $Br_2$) with red phosphorus converts the acid to the $\\alpha$-acyl halide via the acid halide enol, giving the $\\alpha$-chloro (or $\\alpha$-bromo) acid on hydrolysis."
|
||
},
|
||
{
|
||
"id": "15b66694-c883-467a-aa56-d96eae7e8300",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Organic Chemistry - Basic Principles",
|
||
"subtopic": "Basicity of Amines",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The correct order of basic strength in aqueous solution is:",
|
||
"options": {
|
||
"A": "$(CH_3)_2NH > CH_3NH_2 > (CH_3)_3N > NH_3$",
|
||
"B": "$CH_3NH_2 > (CH_3)_2NH > NH_3 > (CH_3)_3N$",
|
||
"C": "$(CH_3)_3N > (CH_3)_2NH > CH_3NH_2 > NH_3$",
|
||
"D": "$NH_3 > CH_3NH_2 > (CH_3)_2NH > (CH_3)_3N$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "In water, basicity is decided by the interplay of $+I$ effect, solvation of the ion and steric hindrance. For methylamines the observed order is $(CH_3)_2NH > CH_3NH_2 > (CH_3)_3N > NH_3$."
|
||
},
|
||
{
|
||
"id": "6f2bd421-5eb5-4517-b501-446c4787b670",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Amines",
|
||
"subtopic": "Carbylamine Reaction",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The carbylamine reaction (foul-smelling isocyanide formation with chloroform and alcoholic KOH) is used to detect:",
|
||
"options": {
|
||
"A": "tertiary amines",
|
||
"B": "secondary amines",
|
||
"C": "primary amines",
|
||
"D": "quaternary ammonium salts"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "$R-NH_2 + CHCl_3 + 3KOH \\to R-NC$ (foul smell) $+ 3KCl + 3H_2O$. Only primary amines (aliphatic or aromatic) give this test; secondary and tertiary amines do not."
|
||
},
|
||
{
|
||
"id": "70960a0c-5a80-46ca-8965-b6fd85e7d559",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Biomolecules",
|
||
"subtopic": "Carbohydrates",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following is a reducing sugar?",
|
||
"options": {
|
||
"A": "sucrose",
|
||
"B": "maltose",
|
||
"C": "starch",
|
||
"D": "cellulose"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Maltose has one free anomeric (hemiacetal) OH group, so it reduces Tollens' and Fehling's reagents. In sucrose both anomeric carbons are involved in the glycosidic linkage, and starch/cellulose are non-reducing polysaccharides."
|
||
},
|
||
{
|
||
"id": "731fd22e-6311-4303-94e1-08426d082e0f",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Biomolecules",
|
||
"subtopic": "Vitamins",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Deficiency of vitamin $B_{12}$ in the human body causes:",
|
||
"options": {
|
||
"A": "scurvy",
|
||
"B": "rickets",
|
||
"C": "beri-beri",
|
||
"D": "pernicious anaemia"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Vitamin $B_{12}$ (cobalamin) deficiency leads to pernicious anaemia. Scurvy — vitamin C; rickets — vitamin D; beri-beri — vitamin $B_1$."
|
||
},
|
||
{
|
||
"id": "fc121ed2-e270-4da3-9aad-3de03777b3dd",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Organic Chemistry - Basic Principles",
|
||
"subtopic": "Tautomerism",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following compounds can exhibit keto-enol tautomerism?",
|
||
"options": {
|
||
"A": "benzophenone",
|
||
"B": "both 2,2-dimethylpropanal and benzophenone",
|
||
"C": "acetone",
|
||
"D": "2,2-dimethylpropanal"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Keto-enol tautomerism requires at least one $\\alpha$-hydrogen on the carbon adjacent to the C=O group. Acetone ($CH_3COCH_3$) has six $\\alpha$-H atoms, so it readily enolises. In 2,2-dimethylpropanal the $\\alpha$-carbon is quaternary (no H), and benzophenone ($C_6H_5COC_6H_5$) has no $\\alpha$-carbon at all, so neither can enolise."
|
||
},
|
||
{
|
||
"id": "d3ebbe37-f224-4b01-9dc3-43ab35a19538",
|
||
"section": "General",
|
||
"subject": "Chemistry",
|
||
"topic": "Organic Chemistry - Basic Principles",
|
||
"subtopic": "Purification Techniques",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In column chromatography, the components of a mixture are separated based on their:",
|
||
"options": {
|
||
"A": "different densities",
|
||
"B": "different adsorption on the stationary phase",
|
||
"C": "different solubility in water",
|
||
"D": "different boiling points"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "In adsorption column chromatography, components are separated by differential adsorption on the stationary phase (alumina/silica) and differential elution by the moving solvent; the most strongly adsorbed component moves slowest."
|
||
},
|
||
{
|
||
"id": "251fd007-8b06-4c4f-aa6b-451a0c80b5a1",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Cell Cycle and Cell Division",
|
||
"subtopic": "Prophase I of Meiosis",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "During which substage of prophase I of meiosis I does crossing over occur, and which enzyme complex mediates it?",
|
||
"options": {
|
||
"A": "Diplotene; topoisomerase",
|
||
"B": "Pachytene; recombinase (Spd1)",
|
||
"C": "Pachytene; recombinase (RPA)",
|
||
"D": "Zygotene; recombinase (Spd1)"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Crossing over occurs between non-sister chromatids of homologous chromosomes during pachytene, and it is catalysed by the enzyme recombinase (Spd1 in the NCERT account). Crossing over is completed and recombination nodules disappear by diplotene."
|
||
},
|
||
{
|
||
"id": "31da5130-3b04-491e-8638-1746d19168f2",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Cell Cycle and Cell Division",
|
||
"subtopic": "Interphase",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "During interphase, DNA replication takes place specifically in the:",
|
||
"options": {
|
||
"A": "$G_2$ phase",
|
||
"B": "$G_1$ phase",
|
||
"C": "$M$ phase",
|
||
"D": "$S$ phase"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "In the $S$ (synthesis) phase the amount of DNA doubles while the chromosome number stays the same; $G_1$ is pre-replication growth, $G_2$ is post-replication growth, and no DNA replication occurs in $M$ phase."
|
||
},
|
||
{
|
||
"id": "cbce8cea-5cb0-41c6-9404-72332ed426c1",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Cell: The Unit of Life",
|
||
"subtopic": "Prokaryotic Cell Structure",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Consider the following statements about prokaryotic cells: (A) They possess 70S ribosomes made of 50S and 30S subunits. (B) The genetic material lies naked in the cytoplasm and is not organised into true chromatin. (C) Mesosomes are infoldings of the plasma membrane that increase the surface area of enzymatic reactions. (D) They contain membrane-bound organelles such as mitochondria and Golgi bodies. How many of the above statements are CORRECT?",
|
||
"options": {
|
||
"A": "1",
|
||
"B": "3",
|
||
"C": "4",
|
||
"D": "2"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "(A), (B) and (C) are correct — prokaryotes have 70S ribosomes (50S + 30S), naked circular DNA without histone-organised chromatin, and mesosomes formed by plasma-membrane infolding. (D) is incorrect because membrane-bound organelles are absent in prokaryotic cells. Hence 3 statements are correct."
|
||
},
|
||
{
|
||
"id": "78cb7042-4626-4b6f-8677-290452e7d4d6",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Cell: The Unit of Life",
|
||
"subtopic": "Cell Organelles",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The primary function of polysomes (polyribosomes) in a cell is:",
|
||
"options": {
|
||
"A": "lipid synthesis",
|
||
"B": "packaging of proteins",
|
||
"C": "translation of mRNA into polypeptides",
|
||
"D": "ATP synthesis"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "A polysome is an mRNA molecule with several ribosomes translating it simultaneously, enabling rapid production of many copies of the same polypeptide. Lipid synthesis is smooth ER, ATP is mitochondria, packaging is Golgi."
|
||
},
|
||
{
|
||
"id": "b51b62da-bf1c-423b-a682-2cb054afa56d",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Cell: The Unit of Life",
|
||
"subtopic": "Endomembrane System",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Consider the following statements about cell organelles: (A) The endomembrane system includes the endoplasmic reticulum, Golgi complex, lysosomes and vacuoles, but excludes mitochondria and chloroplasts. (B) The smooth endoplasmic reticulum is the major site for the synthesis of lipids and steroidal hormones. (C) The inner mitochondrial membrane bears oxysomes ($F_0$–$F_1$ particles) for oxidative phosphorylation. (D) Ribosomes are membrane-bound organelles present in both prokaryotic and eukaryotic cells. How many of the above statements are INCORRECT?",
|
||
"options": {
|
||
"A": "4",
|
||
"B": "1",
|
||
"C": "3",
|
||
"D": "2"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "(A), (B) and (C) are correct — the endomembrane system excludes mitochondria and chloroplasts, SER synthesises lipids and steroids, and oxysomes on the inner mitochondrial membrane carry out oxidative phosphorylation. (D) is incorrect — ribosomes are non-membrane-bound particles. Hence only 1 statement is incorrect."
|
||
},
|
||
{
|
||
"id": "c87f6f77-b60a-4ff7-bbd3-74bf032b86aa",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Biomolecules",
|
||
"subtopic": "Enzymes",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In competitive inhibition of an enzyme, the inhibitor:",
|
||
"options": {
|
||
"A": "binds covalently to the active site",
|
||
"B": "binds only to the enzyme-substrate complex",
|
||
"C": "denatures the enzyme permanently",
|
||
"D": "resembles the substrate and binds at the active site"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "A competitive inhibitor closely resembles the substrate and competes for the active site; its effect can be overcome by increasing substrate concentration. In uncompetitive/non-competitive inhibition the inhibitor binds elsewhere."
|
||
},
|
||
{
|
||
"id": "52fcba0f-763b-4925-a881-33b770e309b0",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Biomolecules",
|
||
"subtopic": "Proteins",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The $\\alpha$-helix secondary structure of proteins is stabilised primarily by:",
|
||
"options": {
|
||
"A": "hydrogen bonds",
|
||
"B": "hydrophobic interactions",
|
||
"C": "peptide bonds",
|
||
"D": "disulphide bonds"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "In the $\\alpha$-helix, intra-chain hydrogen bonds between C=O of one peptide unit and N–H of another stabilize the coiled structure; the peptide bonds themselves form the backbone and are not the stabilising force of the helix."
|
||
},
|
||
{
|
||
"id": "517aea5f-82c7-48e9-8adc-3b3793d20ece",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Transport in Plants",
|
||
"subtopic": "Water Potential",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A plant cell with solute potential $\\Psi_s = -10$ bar is placed in pure water at atmospheric pressure ($\\Psi_p = 0$). The water potential of the cell and the direction of net water movement are:",
|
||
"options": {
|
||
"A": "$\\Psi_w = +10$ bar; water moves out of the cell",
|
||
"B": "$\\Psi_w = -10$ bar; water moves out of the cell",
|
||
"C": "$\\Psi_w = 0$ bar; water moves into the cell",
|
||
"D": "$\\Psi_w = -10$ bar; water moves into the cell"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "$\\Psi_w = \\Psi_s + \\Psi_p = -10 + 0 = -10$ bar. Water moves from higher (less negative) to lower water potential, i.e. from pure water ($\\Psi_w = 0$) into the cell ($\\Psi_w = -10$ bar)."
|
||
},
|
||
{
|
||
"id": "faa16ee1-b41c-479f-a276-f6c3bff729d5",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Transport in Plants",
|
||
"subtopic": "Ascent of Sap — Cohesion-Tension",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following phenomena is chiefly responsible for the upward movement of water through the xylem to the tops of tall trees?",
|
||
"options": {
|
||
"A": "Root pressure",
|
||
"B": "Capillarity",
|
||
"C": "Imbibition by cell walls",
|
||
"D": "Transpiration pull generated by stomatal transpiration"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "By the cohesion-tension (transpiration pull) theory, water evaporating from mesophyll cells creates tension that pulls the continuous water column up the xylem; root pressure is too weak for tall trees and acts mainly at night/mild conditions."
|
||
},
|
||
{
|
||
"id": "5f95f9c0-c83c-4c43-9a6e-d9a79af8384e",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Transport in Plants",
|
||
"subtopic": "Stomatal Movement",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Stomatal opening during the day is promoted by:",
|
||
"options": {
|
||
"A": "efflux of $K^+$ from guard cells",
|
||
"B": "influx of $K^+$ into guard cells",
|
||
"C": "decreased turgidity of guard cells",
|
||
"D": "abscisic acid under low humidity"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "In light, $K^+$ and Cl$^-$ enter guard cells (malate also forms), lowering $\\Psi_s$, so water enters and guard cells become turgid, opening the stoma. ABA promotes $K^+$ efflux and closure."
|
||
},
|
||
{
|
||
"id": "7e91f11f-dc97-4613-a717-9d0060716b14",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Mineral Nutrition",
|
||
"subtopic": "Biological Nitrogen Fixation",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In root nodules of legumes, the enzyme nitrogenase is protected from oxygen by:",
|
||
"options": {
|
||
"A": "haemoglobin",
|
||
"B": "cytochrome oxidase",
|
||
"C": "leghaemoglobin",
|
||
"D": "nitrate reductase"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Leghaemoglobin, a pink oxygen-scavenging pigment produced in the nodule, buffers free oxygen around nitrogenase, which is irreversibly inactivated by $O_2$; the nodule is anoxic inside but the plant still gets oxygen aerobically."
|
||
},
|
||
{
|
||
"id": "c0e34d0d-da50-4f2c-8b23-394fc43b450b",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Mineral Nutrition",
|
||
"subtopic": "Essential Mineral Elements",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which mineral element is a component of the porphyrin ring of chlorophyll and is also an activator of several enzymes of respiration and photosynthesis?",
|
||
"options": {
|
||
"A": "Manganese",
|
||
"B": "Iron",
|
||
"C": "Magnesium",
|
||
"D": "Zinc"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "$Mg^{2+}$ occupies the centre of the porphyrin (chlorin) ring of chlorophyll and also activates enzymes such as RuBisCO, PEP carboxylase, and several respiratory enzymes. Fe and Mn are micronutrients not part of chlorophyll."
|
||
},
|
||
{
|
||
"id": "cf3677ac-2800-44de-944d-a32baccae350",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Photosynthesis",
|
||
"subtopic": "Light Reaction",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The light reaction of photosynthesis occurs in the:",
|
||
"options": {
|
||
"A": "cytosol",
|
||
"B": "grana matrix",
|
||
"C": "stroma of chloroplast",
|
||
"D": "thylakoid membrane"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Photosystems, ETC and ATP synthase are embedded in the thylakoid membranes where light reactions (ATP, NADPH, $O_2$) occur; carbon fixation occurs in the stroma."
|
||
},
|
||
{
|
||
"id": "0081156b-49c1-49e0-a523-e4fcd643385e",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Photosynthesis",
|
||
"subtopic": "Photolysis of Water",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In non-cyclic photophosphorylation, the ultimate electron donor that finally reduces NADP$^+$ is:",
|
||
"options": {
|
||
"A": "$FADH_2$",
|
||
"B": "plastocyanin",
|
||
"C": "NADH",
|
||
"D": "water"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "In Z-scheme non-cyclic electron transport, water is the ultimate electron donor: $H_2O \\to PSII \\to plastoquinone \\to cytochrome\\ b_6f \\to plastocyanin \\to PSI \\to ferredoxin \\to NADP^+$."
|
||
},
|
||
{
|
||
"id": "981594e3-182b-4046-bb22-1c6f12541c04",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Photosynthesis",
|
||
"subtopic": "Calvin Cycle",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The enzyme that catalyses the carboxylation of ribulose-1,5-bisphosphate in the Calvin cycle is:",
|
||
"options": {
|
||
"A": "phosphoglycerate kinase",
|
||
"B": "RuBisCO",
|
||
"C": "PEP carboxylase",
|
||
"D": "Ru5P kinase"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "RuBisCO (ribulose-1,5-bisphosphate carboxylase-oxygenase) carboxylates RuBP to form 2 molecules of 3-PGA in the Calvin cycle."
|
||
},
|
||
{
|
||
"id": "c3c49e91-78d4-401c-81a4-d17e5b838229",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Photosynthesis",
|
||
"subtopic": "C4 Pathway",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In $C_4$ plants, the primary carboxylating enzyme in mesophyll cells is:",
|
||
"options": {
|
||
"A": "RuBisCO",
|
||
"B": "PEP carboxylase",
|
||
"C": "pyruvate dehydrogenase",
|
||
"D": "aldolase"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "In $C_4$ plants, mesophyll cells fix $HCO_3^-$ via PEP carboxylase to form OAA (a 4-C acid); RuBisCO acts later in bundle sheath cells on the $CO_2$ released from the 4-C acid."
|
||
},
|
||
{
|
||
"id": "73be1618-6030-4297-b3b4-1169576b746b",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Photosynthesis",
|
||
"subtopic": "Photorespiration",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following is a major consequence of photorespiration in $C_3$ plants?",
|
||
"options": {
|
||
"A": "It produces extra ATP for the cell",
|
||
"B": "It reduces the oxygenase activity of RuBisCO",
|
||
"C": "It releases $CO_2$ and consumes ATP with no sugar synthesis",
|
||
"D": "It increases photosynthetic yield significantly"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "RuBisCO's oxygenase activity in $C_3$ plants diverts RuBP into the $C_2$ photorespiratory cycle, releasing $CO_2$, consuming ATP, and synthesising no sugar — a major yield limitation."
|
||
},
|
||
{
|
||
"id": "06d4d1f6-cdcd-4dae-9a01-9a9eb62a89e3",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Respiration in Plants",
|
||
"subtopic": "Aerobic Respiration — ATP Yield",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The complete aerobic oxidation of one molecule of glucose yields a net gain of:",
|
||
"options": {
|
||
"A": "30 ATP",
|
||
"B": "38 ATP",
|
||
"C": "40 ATP",
|
||
"D": "36 ATP"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Net ATP from one glucose: glycolysis (8, including NADH shuttle), link reaction (6), Krebs cycle (24) — total $38$ ATP in the NCERT scheme of complete aerobic oxidation."
|
||
},
|
||
{
|
||
"id": "a356851a-15ee-47e0-b3ea-396513b0010c",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Respiration in Plants",
|
||
"subtopic": "Respiratory Quotient",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The respiratory quotient (RQ) for a substrate undergoing complete oxidation is $1.0$. The substrate is:",
|
||
"options": {
|
||
"A": "a hexose sugar",
|
||
"B": "a fat",
|
||
"C": "a protein",
|
||
"D": "an organic acid"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$RQ = \\dfrac{CO_2 \\text{ evolved}}{O_2 \\text{ consumed}}$. For a hexose like glucose: $C_6H_{12}O_6 + 6O_2 \\to 6CO_2 + 6H_2O$, so $RQ = 6/6 = 1.0$. Organic acids give $RQ > 1$, fats and proteins $< 1$."
|
||
},
|
||
{
|
||
"id": "be244a76-187c-474f-ae50-70b855e8b1e8",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Respiration in Plants",
|
||
"subtopic": "Krebs Cycle",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "All the enzymes of the Krebs (TCA) cycle in eukaryotic cells are located in the:",
|
||
"options": {
|
||
"A": "chloroplast stroma",
|
||
"B": "mitochondrial matrix",
|
||
"C": "cytosol",
|
||
"D": "inner mitochondrial membrane"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "In eukaryotes the enzymes of the TCA cycle (except succinate dehydrogenase, which is membrane-bound) are located in the mitochondrial matrix; glycolysis occurs in the cytosol."
|
||
},
|
||
{
|
||
"id": "e603e923-7d1c-41a8-acf9-6f62eadf7111",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Plant Growth and Development",
|
||
"subtopic": "Auxin",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The phenomenon of apical dominance (suppression of lateral bud growth) in plants is caused by:",
|
||
"options": {
|
||
"A": "cytokinin from the roots",
|
||
"B": "auxin produced at the shoot apex",
|
||
"C": "ethylene produced by senescing leaves",
|
||
"D": "abscisic acid in the roots"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Auxin produced at the shoot apex moves basipetally and inhibits growth of lateral buds; decapitation releases lateral buds (this is why hedge pruning promotes bushiness)."
|
||
},
|
||
{
|
||
"id": "5b5ce385-4e59-4768-912a-31febe7900e7",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Plant Growth and Development",
|
||
"subtopic": "Abscisic Acid",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which plant hormone is known to promote abscission of leaves and fruits?",
|
||
"options": {
|
||
"A": "gibberellin",
|
||
"B": "cytokinin",
|
||
"C": "abscisic acid",
|
||
"D": "auxin"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "ABA promotes abscission and senescence, and induces bud dormancy; it also promotes stomatal closure under water stress. (Ethylene also promotes abscission, but among the options ABA is the correct choice.)"
|
||
},
|
||
{
|
||
"id": "3ecbe609-6528-4bc0-981f-49e55376b4c0",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Plant Growth and Development",
|
||
"subtopic": "Photoperiodism",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The critical photoperiod for flowering is the:",
|
||
"options": {
|
||
"A": "duration of darkness required for flowering",
|
||
"B": "length of day (light period) at the threshold for floral response",
|
||
"C": "total hours of light needed to accumulate for flowering",
|
||
"D": "minimum light intensity needed for photosynthesis"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "The critical photoperiod is the day-length threshold for the floral response: long-day plants flower above it and short-day plants below it. The real measured factor is the duration of the uninterrupted dark period, but the critical photoperiod is the day-length threshold."
|
||
},
|
||
{
|
||
"id": "26580449-5f42-4351-afda-5bc9a808613e",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Plant Growth and Development",
|
||
"subtopic": "Vernalisation",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Vernalisation is the:",
|
||
"options": {
|
||
"A": "effect of gravity on root growth",
|
||
"B": "effect of red light on seed germination",
|
||
"C": "effect of low temperature on flowering",
|
||
"D": "effect of day length on tuber formation"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Vernalisation is the induction of flowering by prolonged exposure to low temperature (e.g. winter wheat, barley). It prevents precocious reproductive development in autumn and allows the plant to flower in spring."
|
||
},
|
||
{
|
||
"id": "21f2d89e-0d5b-4ddd-8b91-7584a7700ddd",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Sexual Reproduction in Flowering Plants",
|
||
"subtopic": "Microsporogenesis",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In an anther, each cell of the sporogenous tissue is:",
|
||
"options": {
|
||
"A": "diploid and acts as a pollen mother cell (microspore mother cell)",
|
||
"B": "haploid and forms the generative cell",
|
||
"C": "haploid and forms the vegetative cell",
|
||
"D": "diploid and directly forms the male gametes"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Cells of the sporogenous tissue in the anther are diploid microspore mother cells (pollen mother cells) that undergo meiosis to form microspore tetrads, which develop into pollen grains."
|
||
},
|
||
{
|
||
"id": "99725d86-061d-4238-a2ce-1da5514a5d65",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Sexual Reproduction in Flowering Plants",
|
||
"subtopic": "Pollen Grain Structure",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The outer wall layer of a pollen grain is made up of:",
|
||
"options": {
|
||
"A": "suberin",
|
||
"B": "sporopollenin",
|
||
"C": "cutin",
|
||
"D": "cellulose"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "The exine is made of sporopollenin, one of the most resistant organic materials known, which enables pollen grains to survive harsh conditions for long periods (hence their value in fossils)."
|
||
},
|
||
{
|
||
"id": "747a342a-2916-4b65-8091-83583a266ec1",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Sexual Reproduction in Flowering Plants",
|
||
"subtopic": "Double Fertilisation",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Double fertilisation in angiosperms involves:",
|
||
"options": {
|
||
"A": "fusion of two eggs with one male gamete",
|
||
"B": "two male gametes fusing with the egg",
|
||
"C": "fusion of the two polar nuclei only",
|
||
"D": "syngamy and triple fusion"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Double fertilisation comprises syngamy (one sperm + egg $\\to$ zygote, $2n$) and triple fusion (other sperm + two polar nuclei $\\to$ primary endosperm nucleus, $3n$), both occurring in the embryo sac."
|
||
},
|
||
{
|
||
"id": "b97f944f-d490-4385-9f00-a78dcaeaf06d",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Sexual Reproduction in Flowering Plants",
|
||
"subtopic": "Apomixis and Polyembryony",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Apomixis in flowering plants is:",
|
||
"options": {
|
||
"A": "fusion of gametes without plasmogamy",
|
||
"B": "asexual seed formation without meiosis or syngamy",
|
||
"C": "development of more than one embryo in a seed",
|
||
"D": "germination of seeds within the fruit"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Apomixis is a form of asexual reproduction where seeds form without meiosis and syngamy (e.g. in some Asteraceae and grasses), producing progeny identical to the mother plant — useful for hybrid seed industry."
|
||
},
|
||
{
|
||
"id": "44238643-4425-445b-a231-7414a0f4f1f9",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Principles of Inheritance and Variation",
|
||
"subtopic": "Mendel's Laws",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In a Mendelian dihybrid cross between a true-breeding round-yellow seeded pea plant and a wrinkled-green seeded pea plant, the $F_2$ phenotypic ratio is:",
|
||
"options": {
|
||
"A": "$3:1$",
|
||
"B": "$9:7$",
|
||
"C": "$1:1:1:1$",
|
||
"D": "$9:3:3:1$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "A dihybrid $F_1$ (RrYy) selfed gives the $F_2$ phenotypic ratio $9:3:3:1$ (round-yellow : round-green : wrinkled-yellow : wrinkled-green), showing independent assortment."
|
||
},
|
||
{
|
||
"id": "6a337cbd-c9cc-4e29-a8aa-08a2bf73b49d",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Principles of Inheritance and Variation",
|
||
"subtopic": "Test Cross",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A test cross is used to determine the:",
|
||
"options": {
|
||
"A": "linkage distance between two genes",
|
||
"B": "number of chromosomes in a cell",
|
||
"C": "dominance relationship between two alleles",
|
||
"D": "genotype of a dominant phenotype individual"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "A test cross between an individual with a dominant phenotype and a homozygous recessive parent reveals the unknown genotype: a $1:1$ ratio indicates heterozygosity, while all dominant progeny indicate homozygosity."
|
||
},
|
||
{
|
||
"id": "0cbf33be-2023-4899-8a18-3e71176a97e0",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Principles of Inheritance and Variation",
|
||
"subtopic": "Incomplete Dominance",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Inheritance of flower colour in snapdragon (dog flower) is an example of:",
|
||
"options": {
|
||
"A": "co-dominance",
|
||
"B": "epistasis",
|
||
"C": "complete dominance",
|
||
"D": "incomplete dominance"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "In snapdragon, $RR$ (red) $\\times\\ rr$ (white) gives pink $Rr$ in $F_1$; $F_2$ shows red : pink : white $= 1:2:1$ — genotypic and phenotypic ratios coincide, defining incomplete dominance."
|
||
},
|
||
{
|
||
"id": "5b04914c-32de-4021-b575-c6a0abc2ab0b",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Principles of Inheritance and Variation",
|
||
"subtopic": "Multiple Alleles (ABO)",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "How many genotypes are possible for the ABO blood group system in humans?",
|
||
"options": {
|
||
"A": "$9$",
|
||
"B": "$4$",
|
||
"C": "$8$",
|
||
"D": "$6$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Three alleles $I^A$, $I^B$, $i$ give $3+2+1 = 6$ genotypes: $I^AI^A, I^Ai, I^BI^B, I^Bi, I^AI^B, ii$ (four phenotypes)."
|
||
},
|
||
{
|
||
"id": "5a00aba1-6a4c-427c-acaf-70fa9498ac8f",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Principles of Inheritance and Variation",
|
||
"subtopic": "Sex-linked Inheritance",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "A man with normal blood clotting marries a woman who is a carrier for haemophilia A. The probability that their first son will be haemophilic is:",
|
||
"options": {
|
||
"A": "$75\\%$",
|
||
"B": "$100\\%$",
|
||
"C": "$25\\%$",
|
||
"D": "$50\\%$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Haemophilia A is X-linked recessive. Sons receive the Y from the father and one X from the carrier mother; there is a $50\\%$ chance a son receives the affected X (the $25\\%$ figure refers to all children)."
|
||
},
|
||
{
|
||
"id": "af5fa81c-74ee-4510-a4e3-f22e3437e36e",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Principles of Inheritance and Variation",
|
||
"subtopic": "Search for Genetic Material",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Hershey and Chase's experiment with $^{32}P$ and $^{35}S$ labelled bacteriophages established that:",
|
||
"options": {
|
||
"A": "both DNA and protein are transmitted to the host",
|
||
"B": "RNA is the genetic material of T2 phage",
|
||
"C": "protein enters the bacterial cell during infection",
|
||
"D": "DNA, not protein, is the genetic material of T2 phage"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "$^{32}P$ (DNA label) was found in the bacterial pellet while $^{35}S$ (protein label) remained in the supernatant, proving DNA — not protein — enters the host and directs phage reproduction."
|
||
},
|
||
{
|
||
"id": "9c7665aa-9c5a-4afc-8109-379c22ea1d3d",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Molecular Basis of Inheritance",
|
||
"subtopic": "Transcription Unit",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In a transcription unit, the DNA-dependent RNA polymerase binds at the:",
|
||
"options": {
|
||
"A": "promoter",
|
||
"B": "terminator",
|
||
"C": "operator",
|
||
"D": "structural gene"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "The promoter, located upstream of the structural gene and toward the 3'-end (5' to 3') of the template strand, is the binding site for RNA polymerase; the terminator ends transcription."
|
||
},
|
||
{
|
||
"id": "5f363475-df8c-45fd-bb4a-1d32a7cb14e1",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Molecular Basis of Inheritance",
|
||
"subtopic": "Genetic Code",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The codon AUG serves as:",
|
||
"options": {
|
||
"A": "a codon for proline",
|
||
"B": "initiation codon for translation and codes for methionine",
|
||
"C": "only a stop codon",
|
||
"D": "a nonsense codon"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "AUG is the universal initiation codon and codes for methionine (formyl-methionine in prokaryotes). Stop (nonsense) codons are UAA, UAG and UGA."
|
||
},
|
||
{
|
||
"id": "9c1231d1-b911-478f-b68e-0ad200d17ee0",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Molecular Basis of Inheritance",
|
||
"subtopic": "Lac Operon",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In the lac operon of E. coli, transcription of the structural genes is switched on when:",
|
||
"options": {
|
||
"A": "lactose (inducer) binds the repressor, inactivating it",
|
||
"B": "lactose binds the operator DNA directly",
|
||
"C": "glucose is present in high concentration",
|
||
"D": "the repressor binds the promoter"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Allolactose (the inducer) binds the lac repressor, changing its shape so it cannot bind the operator; RNA polymerase can then transcribe the $lacZ$, $lacY$ and $lacA$ genes."
|
||
},
|
||
{
|
||
"id": "19122766-b5fa-4b70-9f53-438ea2865223",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Molecular Basis of Inheritance",
|
||
"subtopic": "Translation",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In eukaryotic translation, the sequence of assembly is:",
|
||
"options": {
|
||
"A": "tRNA, mRNA, ribosome",
|
||
"B": "mRNA, tRNA, ribosome",
|
||
"C": "ribosome, mRNA, tRNA",
|
||
"D": "ribosome, tRNA, mRNA"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Translation initiates with the two ribosomal subunits assembling around the mRNA, then the initiator tRNA (carrying methionine) occupies the P-site to begin polypeptide synthesis."
|
||
},
|
||
{
|
||
"id": "3bb412db-953b-490c-86aa-ccd76c75062a",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Evolution",
|
||
"subtopic": "Darwinian Natural Selection",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Darwin's theory of evolution by natural selection is primarily based on:",
|
||
"options": {
|
||
"A": "inheritance of acquired characters",
|
||
"B": "survival of the fittest through differential reproduction",
|
||
"C": "genetic drift in small populations",
|
||
"D": "mutation pressure alone"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Darwin proposed that individuals with heritable variations better suited to their environment survive and reproduce more ('survival of the fittest'), leading to gradual evolutionary change; inheritance of acquired characters is Lamarck's idea."
|
||
},
|
||
{
|
||
"id": "144c7603-f019-4d6c-8e8a-78dfd3be90fb",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Evolution",
|
||
"subtopic": "Convergent Evolution",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Consider the following pairs: (a) Wings of butterfly and wings of birds — analogous organs; (b) Forelimbs of humans and wings of bats — analogous organs; (c) Thorns of Bougainvillea and tendrils of Cucurbita — homologous organs; (d) Eyes of octopus and eyes of mammals — homologous organs. How many pairs are CORRECTLY matched?",
|
||
"options": {
|
||
"A": "3",
|
||
"B": "1",
|
||
"C": "2",
|
||
"D": "4"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "(a) and (c) are correctly matched: butterfly and bird wings perform the same function with different structures (analogous), and thorns and tendrils share the same basic structural plan (homologous, modified parts of the shoot system). (b) is wrongly matched — human forelimb and bat wing are homologous organs. (d) is wrongly matched — the eyes of octopus and mammals are analogous organs with different embryonic origins."
|
||
},
|
||
{
|
||
"id": "a59bbd18-9e36-46c3-8989-985ed9ea0eb3",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Ecosystem",
|
||
"subtopic": "Ecosystem — Trophic Levels",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In a terrestrial ecosystem, the greatest standing crop of biomass occurs at the:",
|
||
"options": {
|
||
"A": "primary consumers",
|
||
"B": "secondary consumers",
|
||
"C": "primary producers",
|
||
"D": "tertiary consumers"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Energy and biomass decrease with each successive trophic level (about 10% transfer), so producers (plants) always have the greatest standing crop in a terrestrial ecosystem."
|
||
},
|
||
{
|
||
"id": "8bc8b23b-113b-459c-b7ca-67a71c3d122b",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Ecosystem",
|
||
"subtopic": "Ecological Pyramids",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following ecological pyramids is always upright (never inverted) in any ecosystem?",
|
||
"options": {
|
||
"A": "pyramid of number",
|
||
"B": "pyramid of energy",
|
||
"C": "all pyramids are always upright",
|
||
"D": "pyramid of biomass"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "The pyramid of energy is always upright because of the second law of thermodynamics — energy is lost as heat at each transfer; number and biomass pyramids can be inverted (e.g. parasitic food chains, aquatic ecosystems)."
|
||
},
|
||
{
|
||
"id": "360738e8-6e93-4d00-8033-270d4ed3eebe",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Biodiversity and Conservation",
|
||
"subtopic": "Biodiversity Hotspots",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which one of the following is NOT a biodiversity hotspot of India?",
|
||
"options": {
|
||
"A": "Indo-Burma region",
|
||
"B": "Deccan Plateau",
|
||
"C": "Eastern Himalayas",
|
||
"D": "Western Ghats and Sri Lanka"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "India's biodiversity hotspots are the Western Ghats–Sri Lanka, Indo-Burma and Eastern Himalayas (and more recently the Sundaland/Nicobar region); the Deccan Plateau is not one of them."
|
||
},
|
||
{
|
||
"id": "87b7b042-c735-4ffb-955f-e16e01d4bbb3",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Environmental Issues",
|
||
"subtopic": "Ozone Depletion",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Consider the following statements about ozone depletion: (A) Chlorofluorocarbons release chlorine atoms in the stratosphere that catalytically degrade ozone. (B) The thickness of the ozone column is measured in Dobson units. (C) The Montreal Protocol led to the phase-out of CFC production. (D) Ozone-depleting substances mainly destroy ozone in the troposphere. How many of the above statements are INCORRECT?",
|
||
"options": {
|
||
"A": "1",
|
||
"B": "2",
|
||
"C": "3",
|
||
"D": "4"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "(A), (B) and (C) are correct — CFCs release chlorine radicals that destroy stratospheric ozone, column thickness is expressed in Dobson units, and the Montreal Protocol phased out CFC production. (D) is incorrect because the protective ozone layer lies in the stratosphere, not the troposphere. Hence only 1 statement is incorrect."
|
||
},
|
||
{
|
||
"id": "95c0fac1-c18c-4d04-af31-f4b35628abd3",
|
||
"section": "General",
|
||
"subject": "Botany",
|
||
"topic": "Organisms and Populations",
|
||
"subtopic": "Adaptations",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following is NOT an adaptation of the camel to desert life?",
|
||
"options": {
|
||
"A": "ability to tolerate water loss of up to $25\\%$ of body weight without distress",
|
||
"B": "production of very concentrated urine to conserve water",
|
||
"C": "thin skin with abundant sweat glands for cooling",
|
||
"D": "wide padded feet that prevent sinking in sand"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Camels conserve water: they tolerate large water losses, excrete concentrated urine, and their body temperature rises during the day to avoid sweating. Thin skin with abundant sweat glands would cause excessive water loss — it is not a desert adaptation."
|
||
},
|
||
{
|
||
"id": "2b2c6685-cc38-4df3-abca-e49026123d33",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Animal Kingdom",
|
||
"subtopic": "Phylum Porifera",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In sponges (Phylum Porifera), the body wall is lined internally by:",
|
||
"options": {
|
||
"A": "choanocytes",
|
||
"B": "cnidocytes",
|
||
"C": "myocytes",
|
||
"D": "pinacocytes"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "The spongocoel and the canals of the water canal system are lined internally by choanocytes (collar cells), whose flagella maintain the water current for feeding and gas exchange."
|
||
},
|
||
{
|
||
"id": "177acdc0-5d26-47c6-905c-6bcd679dfca0",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Animal Kingdom",
|
||
"subtopic": "Phylum Cnidaria",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Cnidoblasts (cnidocytes), characteristic of phylum Cnidaria, are used for:",
|
||
"options": {
|
||
"A": "locomotion only",
|
||
"B": "digestion of food",
|
||
"C": "respiration",
|
||
"D": "defence, anchorage and capture of prey"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Cnidoblasts containing the stinging nematocyst are present on tentacles and the body, serving for defence, anchorage and capturing prey."
|
||
},
|
||
{
|
||
"id": "df4354a3-b344-42f3-a028-dd9b2f5fcef3",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Animal Kingdom",
|
||
"subtopic": "Phylum Platyhelminthes",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following is a correct statement about Phylum Platyhelminthes?",
|
||
"options": {
|
||
"A": "They are acoelomate, dorsoventrally flattened, with flame cells for osmoregulation",
|
||
"B": "They are pseudocoelomate and have a complete digestive tract",
|
||
"C": "They exhibit cephalization with a hard exoskeleton",
|
||
"D": "They have a true coelom lined by mesoderm"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Flatworms are bilaterally symmetrical, triploblastic, acoelomate animals with a dorsoventrally flattened body; flame cells (protonephridia) perform osmoregulation and excretion, and the digestive tract is incomplete."
|
||
},
|
||
{
|
||
"id": "6eae494a-7817-427b-a69b-ed758bfb5316",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Animal Kingdom",
|
||
"subtopic": "Phylum Aschelminthes",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Aschelminthes (roundworms) are characterised by all of the following EXCEPT:",
|
||
"options": {
|
||
"A": "segmented body with a true coelom",
|
||
"B": "bilateral symmetry",
|
||
"C": "a complete digestive tract with a muscular pharynx",
|
||
"D": "a body cavity that is not lined by mesoderm (pseudocoelom)"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Aschelminthes are non-segmented pseudocoelomates; their body is NOT segmented and they lack a true coelom. They are bilaterally symmetrical with a complete digestive tract."
|
||
},
|
||
{
|
||
"id": "4595d6a2-a432-41fa-9f9f-b88dc68e7900",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Animal Kingdom",
|
||
"subtopic": "Phylum Annelida",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Consider the following statements about phylum Annelida: (A) The body is metamerically segmented and a true coelom is present. (B) Nereis possesses parapodia, whereas earthworm (Pheretima) and leech (Hirudinaria) lack them. (C) Annelids possess an open type of circulatory system. (D) Nephridia help in osmoregulation and excretion. How many of the above statements are INCORRECT?",
|
||
"options": {
|
||
"A": "1",
|
||
"B": "2",
|
||
"C": "4",
|
||
"D": "3"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "(A), (B) and (D) are correct — annelids are truly coelomate metameric animals; Nereis has parapodia while Pheretima and Hirudinaria do not; nephridia perform excretion and osmoregulation. (C) is incorrect because annelids have a closed circulatory system. Hence only 1 statement is incorrect."
|
||
},
|
||
{
|
||
"id": "f4a27bba-80b6-49d4-a186-a3652d37f87e",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Animal Kingdom",
|
||
"subtopic": "Phylum Arthropoda",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The largest phylum in the animal kingdom in terms of described species is:",
|
||
"options": {
|
||
"A": "Chordata",
|
||
"B": "Arthropoda",
|
||
"C": "Nematoda",
|
||
"D": "Mollusca"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Arthropoda is the largest phylum, containing over two-thirds of all named animal species (insects alone account for a huge share)."
|
||
},
|
||
{
|
||
"id": "acaae1f1-5573-4781-aaa4-735ac366b3b7",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Animal Kingdom",
|
||
"subtopic": "Phylum Echinodermata",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The water vascular system in echinoderms is used for:",
|
||
"options": {
|
||
"A": "nerve conduction",
|
||
"B": "circulation of blood",
|
||
"C": "locomotion, capture of food and respiration",
|
||
"D": "reproduction and excretion only"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "The unique water vascular system of echinoderms (e.g. starfish) operates tube feet used for locomotion, capturing food and respiration; it is not a blood vascular system."
|
||
},
|
||
{
|
||
"id": "ec1a3b46-de45-43d5-9794-8aff38141060",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Animal Kingdom",
|
||
"subtopic": "Phylum Chordata",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Consider the following four statements about phylum Chordata: (A) The notochord is mesodermally derived and is replaced by a cartilaginous vertebral column in adult vertebrates. (B) The nerve cord is dorsal, hollow and single. (C) All chordates possess a post-anal tail throughout their life. (D) Adult frogs do not possess pharyngeal gill slits. How many of the above statements are INCORRECT?",
|
||
"options": {
|
||
"A": "2",
|
||
"B": "4",
|
||
"C": "1",
|
||
"D": "3"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "(A) is correct — the notochord is replaced by a cartilaginous vertebral column in adult vertebrates. (B) is correct — the nerve cord is dorsal, hollow and single. (C) is incorrect — the post-anal tail is present at least in the embryonic stage, but is lost in adults of many chordates (e.g. adult frog, humans). (D) is correct — gill slits occur in the tadpole, not in the adult frog. Hence only 1 statement is incorrect."
|
||
},
|
||
{
|
||
"id": "b451a6a6-c365-460f-853c-2eab9ff42826",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Structural Organisation in Animals",
|
||
"subtopic": "Frog — Digestive System",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In the frog, the digestive tract opens into the cloaca, which also receives openings of the:",
|
||
"options": {
|
||
"A": "kidneys and lungs",
|
||
"B": "spleen and gall bladder",
|
||
"C": "urinary bladder and reproductive tract",
|
||
"D": "liver and pancreas"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "The frog's cloaca is a common chamber receiving the digestive tract, urinary bladder and reproductive tract (biliary and pancreatic ducts open into the duodenum, not the cloaca)."
|
||
},
|
||
{
|
||
"id": "bc158074-208c-400e-848e-9918bd00958a",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Structural Organisation in Animals",
|
||
"subtopic": "Frog — Respiratory System",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which type of respiration occurs in the frog when it is submerged in water?",
|
||
"options": {
|
||
"A": "Pulmonary respiration",
|
||
"B": "Buccopharyngeal respiration",
|
||
"C": "Cutaneous respiration",
|
||
"D": "Tracheal respiration"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "In water, the frog respires through its moist skin (cutaneous respiration); on land it uses buccopharyngeal and pulmonary respiration."
|
||
},
|
||
{
|
||
"id": "f0a741f6-ad79-4868-84e2-2bd95375156d",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Structural Organisation in Animals",
|
||
"subtopic": "Epithelial Tissue",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Ciliated epithelium lines the inner surface of:",
|
||
"options": {
|
||
"A": "trachea and fallopian tubes",
|
||
"B": "blood vessels",
|
||
"C": "urinary bladder",
|
||
"D": "alveoli of lungs"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Ciliated columnar epithelium lines the trachea, bronchi and fallopian tubes; the mucus trap of dust particles is moved by cilia. Blood vessels and alveoli are lined by simple squamous epithelium."
|
||
},
|
||
{
|
||
"id": "f6325bc9-e262-4daf-b291-0f6897d94ddc",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Structural Organisation in Animals",
|
||
"subtopic": "Connective Tissue",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following cells is NOT found in areolar connective tissue?",
|
||
"options": {
|
||
"A": "Mast cells",
|
||
"B": "Fibroblasts",
|
||
"C": "Osteocytes",
|
||
"D": "Macrophages"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Areolar tissue contains fibroblasts, mast cells and macrophages embedded in a semi-fluid matrix; osteocytes occur in bone, a specialised skeletal connective tissue."
|
||
},
|
||
{
|
||
"id": "7eab2ccd-ecf2-453f-82da-cc520b4f8781",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Digestion and Absorption",
|
||
"subtopic": "Salivary Digestion",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which of the following enzymes present in human saliva begins the digestion of starch?",
|
||
"options": {
|
||
"A": "Trypsin",
|
||
"B": "Lipase",
|
||
"C": "Amylase",
|
||
"D": "Pepsin"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Salivary amylase (ptyalin) hydrolyses about 30% of starch into maltose, isomaltose and small dextrins ('maltose') at pH $\\approx 6.8$; trypsin and pepsin act later in the gut."
|
||
},
|
||
{
|
||
"id": "122abebb-7169-4555-a0f3-42c1847c4341",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Digestion and Absorption",
|
||
"subtopic": "Liver and Bile",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Bile juice does NOT contain any enzyme but aids digestion by:",
|
||
"options": {
|
||
"A": "emulsifying fats and providing alkaline pH",
|
||
"B": "hydrolysing proteins into amino acids",
|
||
"C": "digesting nucleic acids",
|
||
"D": "breaking down starch into maltose"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Bile (no enzymes) emulsifies fats into small micelles and makes the medium alkaline for pancreatic enzymes; lipases then hydrolyse the emulsified triglycerides."
|
||
},
|
||
{
|
||
"id": "3c633c4a-70ab-400a-b5ca-492dad699ede",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Digestion and Absorption",
|
||
"subtopic": "Absorption of Digested Products",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The chief site of absorption of digested food in the human alimentary canal is:",
|
||
"options": {
|
||
"A": "small intestine",
|
||
"B": "oesophagus",
|
||
"C": "stomach",
|
||
"D": "large intestine"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "The small intestine, with villi and microvilli increasing surface area, absorbs most digested nutrients; the large intestine mainly absorbs water and some minerals."
|
||
},
|
||
{
|
||
"id": "6f553865-10b1-4d53-9ace-0af32be340f7",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Breathing and Exchange of Gases",
|
||
"subtopic": "Transport of Gases",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Most of the oxygen in human blood is transported as:",
|
||
"options": {
|
||
"A": "dissolved in plasma",
|
||
"B": "oxyhaemoglobin in RBCs",
|
||
"C": "carbaminohaemoglobin",
|
||
"D": "bicarbonate ions"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "About $97\\%$ of $O_2$ is carried bound to haemoglobin as oxyhaemoglobin; only about $3\\%$ is dissolved in plasma."
|
||
},
|
||
{
|
||
"id": "dad13840-77e3-486a-a9d0-2bf4d3df90aa",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Breathing and Exchange of Gases",
|
||
"subtopic": "Carbon Dioxide Transport",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Most of the carbon dioxide in human blood is transported:",
|
||
"options": {
|
||
"A": "as bicarbonate ($HCO_3^-$) ions",
|
||
"B": "dissolved in plasma",
|
||
"C": "as carbonic acid",
|
||
"D": "as carbaminohaemoglobin"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "About $70\\%$ of $CO_2$ travels as bicarbonate (via the chloride shift), about $20-25\\%$ as carbaminohaemoglobin, and the rest dissolved."
|
||
},
|
||
{
|
||
"id": "2aa12584-39d8-4c1c-adee-89ac2fe7755b",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Body Fluids and Circulation",
|
||
"subtopic": "Blood Groups",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which blood group is called the universal recipient and why?",
|
||
"options": {
|
||
"A": "Group B — has anti-A only",
|
||
"B": "Group AB — lacks anti-A and anti-B antibodies in plasma",
|
||
"C": "Group A — has anti-B only",
|
||
"D": "Group O — has both anti-A and anti-B antibodies"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Group AB individuals have both A and B antigens on RBCs but neither anti-A nor anti-B antibodies in plasma, so they can receive blood from all groups."
|
||
},
|
||
{
|
||
"id": "9ad3add3-1a9a-473c-bbc4-2b10277e050d",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Body Fluids and Circulation",
|
||
"subtopic": "Cardiac Cycle",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The pacemaker of the human heart is the:",
|
||
"options": {
|
||
"A": "AV node",
|
||
"B": "bundle of His",
|
||
"C": "Purkinje fibres",
|
||
"D": "SA node"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "The sino-atrial (SA) node in the right atrial wall generates the maximum number of impulses (~70-75 per minute) and sets the rhythm of the heartbeat."
|
||
},
|
||
{
|
||
"id": "3d2e594b-da1b-47ba-8a23-7c534676d0c2",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Excretory Products and their Elimination",
|
||
"subtopic": "Nephron Function",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Reabsorption of glucose, amino acids and major amounts of electrolytes from the glomerular filtrate occurs chiefly in the:",
|
||
"options": {
|
||
"A": "collecting duct",
|
||
"B": "distal convoluted tubule",
|
||
"C": "loop of Henle",
|
||
"D": "proximal convoluted tubule"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "The PCT, lined with brush-border microvilli, reabsorbs about $70-80\\%$ of the filtrate including all glucose and amino acids (and $Na^+$ actively)."
|
||
},
|
||
{
|
||
"id": "aeb1e7d7-ee37-48f9-9e5a-3038e2d3b00e",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Excretory Products and their Elimination",
|
||
"subtopic": "Counter Current System",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The hormone that increases water reabsorption from the distal tubule and collecting duct is:",
|
||
"options": {
|
||
"A": "aldosterone",
|
||
"B": "cortisol",
|
||
"C": "renin",
|
||
"D": "antidiuretic hormone (ADH)"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "ADH (vasopressin) released from the posterior pituitary promotes insertion of aquaporins in the DCT and collecting duct, increasing water reabsorption; without ADH, dilute urine is produced."
|
||
},
|
||
{
|
||
"id": "8fe2e7d0-f382-4282-8054-436cb46499d1",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Locomotion and Movement",
|
||
"subtopic": "Sliding Filament Theory",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "During muscle contraction, which of the following remains constant in length?",
|
||
"options": {
|
||
"A": "A-band",
|
||
"B": "Sarcomere",
|
||
"C": "H-zone",
|
||
"D": "I-band"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "In the sliding filament model, the myosin (thick) filaments of the A-band do not change length; the sarcomere, I-band and H-zone all shorten."
|
||
},
|
||
{
|
||
"id": "e37e49d0-1cc7-4858-bcaf-16e887e95e3f",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Locomotion and Movement",
|
||
"subtopic": "Muscle Metabolism",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Muscle fatigue is caused by accumulation of:",
|
||
"options": {
|
||
"A": "excess ATP in muscle fibres",
|
||
"B": "CO$_2$ from respiration",
|
||
"C": "lactic acid due to anaerobic glycolysis",
|
||
"D": "pyruvic acid from Krebs cycle"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "During intense exercise, oxygen supply is insufficient, so pyruvate is reduced to lactic acid; its accumulation causes fatigue and cramps. The lactic acid is later converted back to pyruvate in the liver (Cori cycle)."
|
||
},
|
||
{
|
||
"id": "efbccac6-b654-4f46-9ced-f94b09c8719d",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Neural Control and Coordination",
|
||
"subtopic": "Nerve Impulse Conduction",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "During the rising phase (depolarisation) of a nerve action potential:",
|
||
"options": {
|
||
"A": "$K^+$ ions move out of the neuron",
|
||
"B": "$Na^+$ ions move into the neuron",
|
||
"C": "the membrane potential becomes more negative",
|
||
"D": "$Cl^-$ ions move into the neuron"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Depolarisation is due to rapid opening of voltage-gated $Na^+$ channels; the influx of $Na^+$ makes the inside positive ($+30$ mV). $K^+$ efflux occurs later in repolarisation."
|
||
},
|
||
{
|
||
"id": "18ca0561-82d1-497b-a13c-3e2767cb87da",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Neural Control and Coordination",
|
||
"subtopic": "Synapse",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "At a chemical synapse, the neurotransmitter is stored in the:",
|
||
"options": {
|
||
"A": "synaptic vesicles of the presynaptic terminal",
|
||
"B": "synaptic cleft",
|
||
"C": "postsynaptic membrane",
|
||
"D": "axon hillock"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Neurotransmitters (e.g. acetylcholine) are stored in synaptic vesicles in the presynaptic terminal and released into the cleft when an action potential arrives."
|
||
},
|
||
{
|
||
"id": "ab885797-1a53-43c3-8a1c-8894e29424a2",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Neural Control and Coordination",
|
||
"subtopic": "The Eye — Photoreceptors",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In dim light (scotopic vision), the photoreceptors mainly responsible are the:",
|
||
"options": {
|
||
"A": "rods",
|
||
"B": "cones",
|
||
"C": "bipolar cells",
|
||
"D": "ganglion cells"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Rods contain rhodopsin and respond to low light intensities (twilight vision); cones (with iodopsin) work in bright light and mediate colour vision."
|
||
},
|
||
{
|
||
"id": "2e400cf6-f249-4d8e-8fcf-0acc41b9b9a8",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Chemical Coordination and Integration",
|
||
"subtopic": "Pancreatic Hormones",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Insulin is secreted by which cells of the islets of Langerhans?",
|
||
"options": {
|
||
"A": "$\beta$-cells",
|
||
"B": "$\u0007lpha$-cells",
|
||
"C": "$\\delta$-cells",
|
||
"D": "acinar cells"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "The $\\beta$-cells of the islets of Langerhans secrete insulin, which promotes cellular glucose uptake and lowers blood glucose; $\\alpha$-cells secrete glucagon."
|
||
},
|
||
{
|
||
"id": "898ce675-9ed7-441b-bce5-7fed077e502a",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Chemical Coordination and Integration",
|
||
"subtopic": "Thyroid Disorders",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Hypersecretion of thyroid hormones in adults causes:",
|
||
"options": {
|
||
"A": "diabetes insipidus",
|
||
"B": "exophthalmic goitre (Graves' disease)",
|
||
"C": "myxoedema",
|
||
"D": "cretinism"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Excess thyroid hormone causes Graves' disease (exophthalmic goitre) with weight loss, tremors and protruding eyes. Cretinism is due to hypothyroidism in children; myxoedema is adult hypothyroidism."
|
||
},
|
||
{
|
||
"id": "51d0d8c7-45e4-400a-b2b6-376a1cb4bda0",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Human Reproduction",
|
||
"subtopic": "Assisted Reproductive Technologies",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In which assisted reproductive technology are gametes collected from the male and female partners and placed directly into the fallopian tube?",
|
||
"options": {
|
||
"A": "ICSI",
|
||
"B": "Artificial insemination",
|
||
"C": "ZIFT",
|
||
"D": "GIFT"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "GIFT (gamete intrafallopian transfer) places unfertilised gametes into the fallopian tube; ZIFT transfers a zygote (early embryo) into the tube; ICSI injects a sperm into an egg in vitro."
|
||
},
|
||
{
|
||
"id": "40c4113d-228f-4666-a359-448c6e3866c0",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Reproductive Health",
|
||
"subtopic": "Contraception",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "CuT, Cu7 and Multiload-375 are examples of:",
|
||
"options": {
|
||
"A": "hormonal contraceptives",
|
||
"B": "surgical methods",
|
||
"C": "barrier methods",
|
||
"D": "copper-releasing IUDs"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "CuT, Cu7 and Multiload-375 are copper-releasing intrauterine devices; the released $Cu^{2+}$ ions suppress sperm motility and fertilising capacity (Saheli is a hormonal pill, Lippes loop a non-medicated IUD)."
|
||
},
|
||
{
|
||
"id": "28c70aa7-c5f8-4f29-b677-90cb23502cff",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Reproductive Health",
|
||
"subtopic": "Natural Methods",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Lactational amenorrhea provides contraception because intense lactation:",
|
||
"options": {
|
||
"A": "thickens cervical mucus irreversibly",
|
||
"B": "causes permanent endometrial atrophy",
|
||
"C": "destroys sperm in the vagina",
|
||
"D": "suppresses ovulation due to high prolactin levels"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "During intense lactation, high prolactin suppresses GnRH and ovulation; the absence of the menstrual cycle during this period is called lactational amenorrhea (effective only up to six months post-partum)."
|
||
},
|
||
{
|
||
"id": "a342f711-4742-441b-ab4e-959e5f6f6c22",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Human Reproduction",
|
||
"subtopic": "Gametogenesis",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The human male gamete carries which sex chromosome(s)?",
|
||
"options": {
|
||
"A": "always Y",
|
||
"B": "either X or Y",
|
||
"C": "both X and Y in the same sperm",
|
||
"D": "always X"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Spermatocytes carry 22 autosomes plus either X or Y; about half the sperm are 22+X and half 22+Y, so the sperm determines the sex of the child (heterogametic male)."
|
||
},
|
||
{
|
||
"id": "19259a52-e3bd-4457-a7e8-d71deada62a1",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Human Reproduction",
|
||
"subtopic": "Placenta",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Which hormone(s) does the human placenta secrete?",
|
||
"options": {
|
||
"A": "oxytocin and ADH",
|
||
"B": "only progesterone",
|
||
"C": "hCG, hPL, oestrogens, progesterone",
|
||
"D": "FSH and LH"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "The placenta is a temporary endocrine gland secreting hCG, hPL, oestrogens, progesterone and relaxin; FSH/LH come from the pituitary and oxytocin/ADH from the hypothalamus-pituitary."
|
||
},
|
||
{
|
||
"id": "d6692dfb-48d6-401d-9944-ff7857e193d8",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Human Reproduction",
|
||
"subtopic": "Menstrual Cycle",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Ovulation in a typical 28-day human menstrual cycle is triggered by:",
|
||
"options": {
|
||
"A": "surge of LH around day 14",
|
||
"B": "rise in progesterone on day 21",
|
||
"C": "fall in oestrogen on day 14",
|
||
"D": "peak FSH on day 7"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "High oestrogen exerts positive feedback on the pituitary, causing a mid-cycle LH surge (around day 14) that ruptures the Graafian follicle and releases the ovum."
|
||
},
|
||
{
|
||
"id": "8a6ed8c6-1cdb-444c-b171-12d812bbb6f7",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Reproductive Health",
|
||
"subtopic": "Amniocentesis",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Amniocentesis is a technique used to:",
|
||
"options": {
|
||
"A": "measure maternal blood hormone levels",
|
||
"B": "visualise the foetus using ultrasound only",
|
||
"C": "assess foetal well-being by withdrawing amniotic fluid for chromosomal analysis",
|
||
"D": "induce labour at term"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Amniocentesis withdraws a small amount of amniotic fluid containing foetal cells for chromosomal and metabolic disorder testing; its misuse for sex determination has been legally banned in India."
|
||
},
|
||
{
|
||
"id": "7c6e3f95-0bfd-4ff2-a25b-b4db3e59952e",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Human Health and Disease",
|
||
"subtopic": "Malaria",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Consider the following statements about the malarial parasite Plasmodium: (A) Sporozoites injected by the female Anopheles mosquito first multiply inside the RBCs of the human host. (B) The parasite reproduces asexually inside human RBCs, and the rupture of RBCs is associated with the release of a toxin causing recurring fever. (C) Gametocytes taken up by the mosquito complete their sexual cycle in the mosquito's gut. (D) The female Anopheles mosquito is the definitive (final) host of Plasmodium. How many of the above statements are CORRECT?",
|
||
"options": {
|
||
"A": "1",
|
||
"B": "2",
|
||
"C": "4",
|
||
"D": "3"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "(A) is incorrect — sporozoites first reach and multiply inside liver (hepatocyte) cells, not RBCs. (B), (C) and (D) are correct: asexual multiplication occurs in RBCs with toxin release, gametocytes sexualise in the mosquito gut, and the female Anopheles is the definitive host. Hence 3 statements are correct."
|
||
},
|
||
{
|
||
"id": "0677bd07-ed03-4969-8ef3-68924278721e",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Human Health and Disease",
|
||
"subtopic": "Antibodies",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Each antibody molecule (e.g. IgG) has the structure:",
|
||
"options": {
|
||
"A": "one heavy chain and one light chain",
|
||
"B": "two heavy chains and two light chains joined by disulphide bonds",
|
||
"C": "four heavy chains only",
|
||
"D": "one light chain and three heavy chains"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "An antibody is a 'Y'-shaped heterotetramer with 2 heavy + 2 light polypeptide chains held by disulphide bonds; the tips of the arms form the antigen-binding sites."
|
||
},
|
||
{
|
||
"id": "2287fa5b-af9c-4660-8075-f21829317183",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Human Health and Disease",
|
||
"subtopic": "Immunity Types",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Consider the following pairs: (a) IgA antibodies in colostrum — passive immunity; (b) Antivenom injection — active immunity; (c) Recovery from chickenpox — active immunity; (d) Vaccination against polio — passive immunity. Which pairs are CORRECTLY matched?",
|
||
"options": {
|
||
"A": "(a), (c) and (d)",
|
||
"B": "(a) and (c) only",
|
||
"C": "All four pairs",
|
||
"D": "(a), (b) and (d)"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "Colostrum IgA is ready-made antibody transfer (passive), and recovery from chickenpox leaves memory-based active immunity — both correctly paired. Antivenom provides passive immunity (pre-formed antibodies), and vaccination induces active immunity, so (b) and (d) are wrongly paired."
|
||
},
|
||
{
|
||
"id": "78f2d751-16f4-41e9-a260-7bfa8868911a",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Microbes in Human Welfare",
|
||
"subtopic": "Biogas Production",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Consider the following statements about biogas: (A) Biogas contains up to 30% methane. (B) Methanobacterium, an anaerobic bacterium, produces large quantities of methane along with $CO_2$ and $H_2S$. (C) Biogas is produced under aerobic conditions. (D) The biogas technology was developed in India by the joint efforts of IARI and NEERI. How many of the above statements are INCORRECT?",
|
||
"options": {
|
||
"A": "2",
|
||
"B": "3",
|
||
"C": "4",
|
||
"D": "1"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "(A) is incorrect — biogas is 50–70% methane, not 30%. (C) is incorrect — methanogens are strict anaerobes, so production is anaerobic. (B) and (D) are correct per NCERT (Methanobacterium composition; IARI and NEERI developed the technology). Hence 2 statements are incorrect."
|
||
},
|
||
{
|
||
"id": "3aa72c6f-afa2-4c6b-b1d7-4570454ac0e3",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Microbes in Human Welfare",
|
||
"subtopic": "Antibiotics",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Consider the following statements about antibiotics: (A) Penicillin was the first antibiotic discovered and is a narrow-spectrum antibiotic. (B) Broad-spectrum antibiotics are effective against a wide range of Gram-positive and Gram-negative bacteria. (C) Antibiotics are ineffective against viruses. (D) Streptomycin was effective against tuberculosis. How many of the above statements are CORRECT?",
|
||
"options": {
|
||
"A": "2",
|
||
"B": "4",
|
||
"C": "1",
|
||
"D": "3"
|
||
},
|
||
"correct_answer": {
|
||
"value": "B"
|
||
},
|
||
"solution_text": "All four statements are correct: penicillin (Fleming, 1928) is narrow-spectrum; broad-spectrum antibiotics act on both Gram-positive and Gram-negative bacteria; antibiotics act against bacteria, not viruses; and streptomycin was the first effective antituberculosis drug. Hence the answer is 4."
|
||
},
|
||
{
|
||
"id": "cd92986a-6683-46c9-9c95-56ae05efbcff",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Biotechnology and its Applications",
|
||
"subtopic": "PCR",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "The three sequential steps of a PCR cycle, in order, are:",
|
||
"options": {
|
||
"A": "denaturation, annealing, extension",
|
||
"B": "annealing, denaturation, extension",
|
||
"C": "denaturation, extension, annealing",
|
||
"D": "extension, annealing, denaturation"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "Each PCR cycle: (1) denaturation of dsDNA at ~$94-95^\\circ$C, (2) primer annealing at ~$50-65^\\circ$C, (3) extension of the primer by Taq DNA polymerase at ~$72^\\circ$C."
|
||
},
|
||
{
|
||
"id": "dd7ff0f2-176d-4695-a3ff-22a8ab70d5e4",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Biotechnology and its Applications",
|
||
"subtopic": "Genetically Modified Organisms",
|
||
"difficulty": "Easy",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "'Golden rice' is a genetically modified rice variety developed to accumulate:",
|
||
"options": {
|
||
"A": "iron",
|
||
"B": "lysine",
|
||
"C": "vitamin C",
|
||
"D": "$\beta$-carotene (provitamin A)"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "Golden rice carries genes of the $\\beta$-carotene biosynthetic pathway, giving the grain a golden colour and helping combat vitamin A deficiency."
|
||
},
|
||
{
|
||
"id": "faeca54e-d1d4-4907-88c9-be58c0daf4a4",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Biotechnology and its Applications",
|
||
"subtopic": "Bt Toxin",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "Bt toxin genes used in Bt cotton are obtained from:",
|
||
"options": {
|
||
"A": "Rhizobium meliloti",
|
||
"B": "Escherichia coli",
|
||
"C": "Agrobacterium tumefaciens",
|
||
"D": "Bacillus thuringiensis"
|
||
},
|
||
"correct_answer": {
|
||
"value": "D"
|
||
},
|
||
"solution_text": "The cry genes of the soil bacterium Bacillus thuringiensis encode insecticidal crystal (Cry) proteins; their inclusion in cotton gives resistance to bollworms."
|
||
},
|
||
{
|
||
"id": "4e8681f0-ad59-4233-8a9f-6c7df376ccf1",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Evolution",
|
||
"subtopic": "Hardy-Weinberg Principle",
|
||
"difficulty": "Hard",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In a population at Hardy-Weinberg equilibrium, the frequency of the recessive phenotype ($aa$) is $0.16$. The frequency of heterozygotes ($Aa$) is:",
|
||
"options": {
|
||
"A": "$0.48$",
|
||
"B": "$0.40$",
|
||
"C": "$0.16$",
|
||
"D": "$0.24$"
|
||
},
|
||
"correct_answer": {
|
||
"value": "A"
|
||
},
|
||
"solution_text": "$q^2 = 0.16 \\Rightarrow q = 0.4$, so $p = 1 - 0.4 = 0.6$. Heterozygotes $= 2pq = 2 \\times 0.6 \\times 0.4 = 0.48$."
|
||
},
|
||
{
|
||
"id": "ef1df712-994c-412f-9d7f-1eb2c03c93e7",
|
||
"section": "General",
|
||
"subject": "Zoology",
|
||
"topic": "Evolution",
|
||
"subtopic": "Origin of Life",
|
||
"difficulty": "Medium",
|
||
"type": "MCQ_Single",
|
||
"language": "English",
|
||
"question_text": "In the Miller-Urey experiment (1953), which conditions were used in the closed apparatus to simulate the primitive Earth atmosphere?",
|
||
"options": {
|
||
"A": "$N_2$, $O_2$, $Ar$ with high pressure",
|
||
"B": "$CO_2$, $O_2$, $H_2O$ with electric discharges",
|
||
"C": "$CH_4$, $NH_3$, $H_2$ and water vapour with electric discharges",
|
||
"D": "$O_2$, $N_2$, $CO_2$ with ultraviolet light"
|
||
},
|
||
"correct_answer": {
|
||
"value": "C"
|
||
},
|
||
"solution_text": "Miller and Urey circulated $CH_4$, $NH_3$, $H_2$ and $H_2O$ (steam) past electric sparks for a week, producing amino acids such as glycine and alanine — evidence for chemical (abiotic) origin of organic molecules in a reducing atmosphere."
|
||
}
|
||
] |