Physics Past Paper Questions QPT 6 (1) PDF

## Physics Questions ### Q1. Single Correct The work function of three photosensitive materials used to build photoelectric devices are given as: Sodium (2.75 eV), copper (4.65 eV) and gold (5.1 eV). Which of the following statements is correct. (The frequency of visible light lies in the range 4 x...

## Physics Questions ### Q1. Single Correct The work function of three photosensitive materials used to build photoelectric devices are given as: Sodium (2.75 eV), copper (4.65 eV) and gold (5.1 eV). Which of the following statements is correct. (The frequency of visible light lies in the range 4 x 10¹⁴ Hz to 8 × 10¹⁴Hz) ? * A Devices built by copper and gold can operate with visible light. * B Devices built using sodium can operate with ultraviolet light. * C All the devices can operate with infrared light. * D All the devices can operate with visible light. ### Q2 Single Correct If E = energy, G = gravitational constant, I = impulse and M = mass, then dimensions of *GIM² / E²* are same as that of. * A Time * B Mass * C Length * D Force ### Q3 Single Correct A force F = (3xy – 5z) j + 4zk is applied to a particle. The work done by the force when the particle moves from point (0, 0, 0) to point (2, 4, 0) as shown in the figure is: * A 280 J / 5 * B 140 J / 5 * C 232 J / 5 * D 192 J / 5 The figure shows a graph with y = x². Point (0, 0, 0) is at the origin. Point (2, 4, 0) is on the curve. ### Q4. Single Correct A soap bubble (surface tension = T) is charged to a maximum surface density of charge = σ. When it is just going to burst, its radius R is given by: * A R = σ² / 8ε₀T * B R = 8ε₀T / σ² * C R = σ / √8ε₀T * D R = √8ε₀T / σ ### Q5. Single Correct A long straight wire of radius a carries a steady current i. The current is uniformly distributed across its cross section. The ratio of the magnetic field at a/2 and 2a is: * A 1/2 * B 1/4 * C 4 * D 1 ### Q6. Single Correct The primary and secondary coils of a transformer have 50 and 1500 turns respectively. If the magnetic flux ꭤ linked with the primary coil is given by ꭤ = ꭤ₀ + 4t, where ꭤ is in webers, t is time in second and ꭤ₀ is a constant, the output voltage across the secondary coil is equal to 60 k V, then k is---- * A 5 * B 4 * C 3 * D 2 ### Q7 Single Correct A solid sphere of mass M and radius R has a spherical cavity of radius R/2 such that the centre of cavity is at distance R/2 from the centre of the sphere. A point mass m is placed inside the cavity at a distance R/4 from the centre of sphere. The gravitational pull between the sphere and the point mass m is: * A 11GMm / R² * B 14GMm / R² * C GMm / 2R² * D GMm / R² ### Q8. Single Correct Statement - 1: Two tuning forks having frequency 410 Hz and 524 Hz are kept close and made to vibrate. Beats will not be heard. Statement - 2: Sound waves superimpose only when the frequencies of superposing waves are equal or nearly equal. * A Statement - 1 is True, Statement - 2 is True; Statement - 2 is a correct explanation for Statement - 1. * B Statement - 1 is True, Statement - 2 is True; Statement - 2 is NOT a correct explanation for Statement - 1. * C Statement - 1 is True, Statement - 2 is False. * D Statement - 1 is False, Statement - 2 is True. ### Q9. Single Correct A dipole of dipole moment p = 2i – 3j + 4k is placed at the point A(2, 3, 1). The electric potential due to this dipole at the point B(4, -1, 0) is equal to (All the parameters specified here are in SI units.), * A 2 × 10⁹V * B -2 × 10⁹V * C 3 × 10⁹V * D -3 × 10⁹V ### Q10 Single Correct The temperature of 5 moles of a gas at constant volume is changed from 100 °C to 120 °C. The change in internal energy is 80 J. The total heat capacity of the gas at constant volume will be in J/K is : * A 8 * B 4 * C 0.8 * D 0.4 ### Q11 Single Correct The energy of a photon is equal to the kinetic energy of a proton. The energy of the photon is E. Let λ₁ be the de-Broglie wavelength of the proton and λ₂ be the wavelength of the photon. The ratio λ₁ / λ₂ is proportional to? * A E⁰ * B E^-1/2 * C E^-1 * D E^-2 ### Q12 Single Correct A cyclic process ABCA is shown in P - T diagram. What would be its P - V graph? The figure shows four possible graphs of a cyclic process with pressures on the y-axis and volume on the x-axis. ### Q13 Single Correct For the shown situation, if a collision between blocks A and B is perfectly elastic, then find the maximum energy (in joules) stored in the spring. The figure shows three blocks placed on a frictionless surface: Block A with a mass of 3 kg, Block B with a mass of 3 kg that is attached to a spring, and Block C with a mass of 6 kg. Block A is moving with a velocity of 2 m/s towards Block B. * A 4 * B 2 * C 1 * D 3 ### Q14 In the circuit shown (figure), calculate the current through 6 V battery. The figure shows a circuit with: A 6V battery connected in series with a 2ohm resistor. A 5V battery connected in parallel with a 4ohm resistor. A 4V battery connected in parallel with a 2ohm resistor and a 3ohm resistor. * A (1/4) A * B (1/8) A * C (1/2) A * D None of these ### Q15. Single Correct A diffraction pattern is obtained using a beam of red light. What happens if the red light is replaced by blue light? * A Diffraction bands become narrower and crowded together. * B Diffraction bands become broader and farther apart. * C Bands disappear * D Diffraction band firstly become narrower and then become broader. ### Q16 Single Correct A screw gauge gives the following reading when used to measure the diameter of a wire. Main scale reading: 0 mm Circular scale reading: 52 divisions Given that 1 mm on the main scale corresponds to 100 divisions of the circular scale. The diameter of the wire from the above data is * A 0.052 cm * B 0.026 cm * C 0.005 cm * D 0.52 cm ### Q17 The space has electromagnetic field which varies with time whose variation is given as. * -B₀ k if 0 ≤ t ≤ π / qB₀ * B₀ j if π / qB₀ ≤ t ≤ 2π / qB₀ * 0 if 2π / qB₀ ≤ t < ∞ and E = * 0 if 0 ≤ t ≤ 2π / qB₀ * -E₀ k if 2π / qB₀ ≤ t < ∞ A charge particle having mass m and positive charge q is given velocity v₀ i at origin at t = 0 sec. The coordinate of point on xy plane when it again passes through xy plane for the first time is of the form (πmv₀ / q, √(πmv₀ / E₀B₀), πmv₀ / qB₀, 0). Find x + y? * A 5 * B 6 * C 3 * D 4 ### Q18 Single Correct A wheel of moment of inertia 2.5 Kg-m² has an initial angular velocity of 40 rads^-1. A constant torque of 10 Nm acts on the wheel. The time during which the wheel is accelerated to 60 rads^-1 is..... * A 6s * B 5 s * C 4.5 s * D 4 s ### Q19 Single Correct A beaker contains water up to a height h₁ and kerosene of height h₂ above water so that the total height of (water +kerosene) is (h₁ + h₂). Refractive index of water is μ₁ and that of kerosene is μ₂. The apparent shift in the position of the bottom of the beaker when viewed from above is? * A ( 1 - 1/ μ₁ )h₂ + ( 1 - 1/ μ₂ )h₁ * B ( 1 + 1/ μ₁ )h₁ + ( 1 + 1/ μ₂ )h₂ * C ( 1 - 1/ μ₁ )h₁ + ( 1 - 1/ μ₂ ) h₂ * D ( 1 + 1/ μ₁ )h₂ - ( 1 + 1/ μ₂ )h₁ ### Q20 Single Correct The escape velocity of an object from a planet is 16kms^-1. If the escape velocity of the object from another planet having twice the density and three times the radius of the planet is v√2 ms^-1, then the value of v is * A 12 * B 48 * C 18 * D 36 ### Q21 Numerical A Zener diode of Zener break-down voltage 10 V is connected as shown in the figure. Current through Zener diode is The figure shows a circuit with a 12V battery connected in series with a 1500 ohm resistor and a Zener diode. The Zener diode is connected in parallel with a 500 ohm resistor and an unknown resistor labeled as R₂ ### Q22 Numerical A solenoid of length 60 cm with 15 turns per cm and area of cross section 4 x 10^-3 m² completely surrounds another co-axial solenoid of same length and area of cross-section 2 × 10^-3 m² with 40 turns per cm. Mutual inductance of the system is ____mH. (Nearest Integer) ### Q23 Numerical Position (in m) of a particle moving on a straight line varies with time (in sec) as x = t³ / 3 - 3t² + 8t + 4 (m). Consider the motion of the particle from t = 0 to t = 5 sec. S₁ is the total distance travelled and S₂ is the distance travelled during retardation. If S₁ / S₂ = (3a+2) / 11 then find α. ### Q24 Numerical Two steel wires of same length but radii r and 2r are connected together end to end and tied to a wall as shown. The force stretches the combination by 10 mm. How far does the midpoint A move. (in mm) The figure shows two steel wires connected to a wall and pulled by a force F. The first wire has radius r and length L. The second wire has radius 2r and length L. The midpoint A is where the two wires are connected. ### Q25 Numerical A uniform thin rod of mass 'm' and length √3 l is released from rest from horizontal position as shown. When it passes through the vertical line AD, it gets broken at point 'C' due to some reason. Find the angle in radian rotated by rod BC till. Its centre of mass passes through the horizontal line PQ from the instant of breakage. (g = 10 m/s²) (hinge is smooth and there is no thrust on one part of rod due to the other part at the time of breaking.) The figure shows a rod of length √3 l that starts horizontally. The rod is hinged at point A and is released, causing it to fall. It breaks at point C. The distance from the hinge to the point where the rod breaks is l. Point D is directly below point A and is a distance 10l from point A. ### Q26 Single Correct The increasing order of Ag⁺ ion concentration in * I. Saturated solution of AgCl * II. Saturated solution of AgI * III. 1M Ag(NH₃)₂⁺ in 0.1M NH₃ * IV. 1M Ag(CN)₂^- in 0.1M KCN Given: * K_sp of AgCl = 1.0 × 10^-10 * K_sp of AgI = 1.0 × 10^-16 * K_a of Ag(NH₃)₂⁺ = 1.0 × 10^-8 * K_a of Ag(CN)₂^- = 1.0 × 10^-21 * A I < II < III < IV * B IV < III < II < I * C IV < II < III < I * D IV < II < I < III ### Q27 Single Correct The electronic configurations for some neutral atoms are given below * (I) 1s², 2s² 2p⁶, 3s² * (II) 1s², 2s² 2p⁶, 3s¹ * (III) 1s², 2s² 2p⁶, 3s² 3p² * (IV) 1s², 2s² 2p⁶, 3s² 3p³ Which of these is expected to have the highest second ionisation enthalpy? * A I * B II * C III * D IV ### Q28 Single Correct Identify the correct method for the synthesis of the compound shown below from the following alternatives. The figure shows a 6-member ring with a nitrogen atom and a double bond between the nitrogen atom and the carbon atom to the right of it. To the right of the ring is a CH₃ group. ### Q29 Single Correct In the following sub questions, choose the correct answer from among the following possibilities and select correct code of your answer (Answer of 1, 2, 3 and 4 respectively) * 1) The most stable low valent halide (1) GeCl₂ (2) SnCl₂ (3) PbCl₂. * 2) A non existing halide (1) SnCl₄ (2) PbCl₄ (3) PbI₄. * 3) A purely acidic oxide (1) PbO₂ (2) SnO₂ (3) SiO₂ * 4) Thermally most stable hydride (1) NH₃ (2) PH₃ (3) AsH₃. * A 3,2,1,3 * B 1, 3, 3, 1 * C 3,3,3,1 * D 1, 1, 1, 3 ### Q30 Single Correct Which of the following is a correct order of bond order? * A C₂ < NO < He₂⁺ < O₂ * B NO < C₂ < O₂ < He₂⁺ * C He₂⁺ < O₂ < NO < C₂ * D He₂⁺ < O₂ < C₂ < NO ### Q31 Single Correct A sample of hydrogen atoms de-excites from 6th excited state to the ground state in one or more electronic transitions. If no spectral line is obtained in the Paschen and Brackett series, then the maximum number of spectral lines of different photon energies obtained will be * A 21 * B 15 * C 10 * D 7 ### Q32 Single Correct The correct statement is. * A BI₃ is the weakest Lewis acid among the boron halides * B there is minimum ππ - ππ back bonding in BF₃ * C BF₃ is the strongest Lewis acid among the other boron halides * D there is maximum ππ - ππ back bonding in BF₃ ### Q33 Single Correct. In the reaction NH₂ (i) Br₂/HOH (ii) NaNO₂/HCI (X), 'X' will be (iii) HF/BF₃ (iv) Δ * A p-Bromofluorobenzene * B 2, 4, 6-Tribromofluorobenzene * C p-Bromoaniline * D 1. 3, 5-Tribromobenzene ### Q34 Single Correct Match list I with list II and select the correct answer using the codes given below the lists. * List I (Pair of isomers) - (I) [Co(NH₃)₆] [Cr(CN)₆] - (II) [Cr(NH₃)₆] [Co(CN)₆] - (III) [PrCl₂(NH₃)₄]Br₂ - (IV) [PrBr₂(NH₃)₄] Cl₂ - (v) [Co(SCN)(NH₃)₅] Cl₂ - (VI) [Co(NCS) (NH₃)₅]Cl₂ - (VII) [Cr₂(H₂O)₆]Cl₃] - (viII) [CrCl₂(H₂O)₄]Cl.2H₂O * List II (Type of isomerism) - 1. Ionization - 2. Hydrate - 3. Coordination - 4. Geometrical - 5. Linkage isomerism * A P q r s 4 1 5 2 * B P q r s 1 3 2 5 * C P q r s 3 1 5 2 * D P q r s 1 3 5 2 ### Q35 Single Correct Among the following molecules/ions, what is the correct order of increasing s-character (in percentage) in the hybrid orbitals? * (I) CO₃^2- * (II) XeF₄ * (III) I₃^- * (IV) NCl₃ * (V) BeCl₂ * A II < III < IV < I < V * B II < IV < III < V < I * C III < II < I < V < IV * D II < IV < III < I < V ### Q36 Single Correct Identify the set of acidic oxides. * A Na₂O, CaO, BaO * B ZnO, PbO, BeO * C CO, NO, N₂O * D Mn₂O₇, CrO₃, V₂O₅ ### Q37. Single Correct If enthalpy of hydrogenation of C₆H₆ (1) into C₆H₁₂ (1) is -205 kJ and resonance energy of C₆H₆ (1) is -152 kJ mol^-1 then enthalpy of hydrogenation of The figure shows a hexagon with a double bond between the top two carbons and another double bond between the bottom two carbons. (1) to C₆H₁₂(1) is? [Assume enthalpiies of vapourisation of all liquids involved are equal]. * A -535.5 kJ/mol * B -238 kJ/mol * C -357 kJ/mol * D -119kJ/mol ### Q38 Single Correct Assertion: La (Z = 57) belongs to the d-block and is an element of group 3 of the periodic table. Reason: All Lanthanoids belong to the group 3 of the periodic table. * A Both the assertion and reason statements are true and the reason is the correct explanation of the assertion * B Both assertion and reason statements are true but the reason is not the correct explanation of the assertion. * C The assertion statement is true but the reason statement is false * D Both the assertion and reason statements are false ### Q39 Single Correct For a complex reaction P → Products Ea₁ = 200 kJ/mol, Ea₂ = 90 kJ/mol, Ea₃ = 80 kJ/mol Overall rate constant k is related to individual rate constant by the equation k = (k₁k₂ / k₃ )^2/3. Activation energy (kJ/mol) for the overall reaction is (mark answer to nearest integer) * A 240 * B 160 * C 210 * D 140 ### Q40 Single Correct Total number of aromatic compounds from below is The figure shows four compounds: * Compound 1: A 6-member ring with a double bond between the top two carbons and another double bond between the bottom two carbons. To the right of the top carbon is a NH₂ group. * Compound 2: Two fused 6-member rings with two double bonds in each ring. * Compound 3: A 5-member ring with one double bond and an oxygen atom on the top left corner and a positive symbol directly above the oxygen atom. * Compound 4: A 6-member ring with one double bond and an oxygen atom on the top left corner and a nitrogen atom on the top right corner. * A 1 * B 4 * C 2 * D 3 ### Q41 Final product (p) in the sequence of reaction is The figure shows a sequence of reactions with starting material as a cyclohexane ring with bromine atom attached to the top right carbon. * A Br/CCl₄ → A → NaNH₂ → B → dil. H₂SO₄/HgSO₄ →C → NaOD/D₂O(excess) → P * A: Cyclohexane ring with bromine atom attached to the top right carbon and a double bond between the two carbons to the left of the bromine atom. * B: Cyclohexane ring with a single bond between the top right carbon and a carbon atom. The carbon atom is connected to a triple bond with another carbon atom. To the right of the triple bond is a hydrogen atom. * C: Cyclohexane ring with a single bond between the top right carbon and a double bond between the next carbon atom and a carbon atom. To the right of the double bond is a hydrogen atom. * P: Cyclohexane ring with a single bond between the top right carbon and a double bond between the next carbon atom and a carbon atom. To the right of the double bond is a deuterium atom. * A Cyclohexane ring with a single bond between the top right carbon and a double bond between the next carbon atom and a carbon atom. To the right of the double bond is a deuterium atom. * B Cyclohexane ring with a single bond between the top right carbon and a double bond between the next carbon atom and a carbon atom. To the right of the double bond is a hydrogen atom. * C Cyclohexane ring with a single bond between the top right carbon and a double bond between the next carbon atom and a carbon atom. To the right of the double bond is a CONa+CHD₃ group. * D Cyclohexane ring with a single bond between the top right carbon and a double bond between the next carbon atom and a carbon atom. To the right of the double bond is a deuterium atom. ### Q42 The major product of the following reaction is The figure shows a compound with a phenyl group on the left and a three carbon chain with a bromine atom attached to the second carbon of the chain. * A Phenyl group on the left and a three carbon chain with a double bond between the first and second carbon, and a double bond between the second and third carbon. * B Phenyl group on the left and a four carbon chain with a double bond between the first and second carbon and a double bond between the third and fourth carbon. * C Phenyl group on the left and a four carbon chain with a double bond between the first and second carbon, and a double bond between the second and third carbon. * D Phenyl group on the left and a four carbon chain with a double bond between the first and second carbon and a double bond between the second and third carbon. ### Q43 Single Correct Select the compound which cannot act as an oxidising agent and reducing agent? * A HNO₂ * B H₂O₂ * C HClO₄ * D SO₂ ### Q44 Single Correct The coordination number of Ni²⁺ is 4. NiCl₂ + KCN (excess) → A (cyano complex) NiCl₂ + conc. HCl (excess) → B (chloro complex) The IUPAC name of A and B are * A Potassium tetracyanonickelate (II), potassium tetrachloronickelate (II) * B Tetracyanopotassiumnickelate (II), tetrorachloropotassiumnickelate (II) * C Tetracyanonickel (II), tetrachloronickel (II) * D Potassium tetracvanonickel (II), potassium tetrachloronickel (II) ### Q45 Single Correct The major product B formed in the following reaction sequence is: The figure shows a compound with a phenyl group on the left and a three carbon chain with a CHO group on the second carbon of the chain and a methoxy group on the first carbon of the chain. * A Phenyl group on the left and a three carbon chain with two chlorine atoms on the second carbon of the chain. * B Phenyl group on the left and a three carbon chain with a methoxy group attached to the second carbon of the chain. * C Phenyl group on the left and a three carbon chain with the methoxy group on the second carbon of the chain. * D Phenyl group on the left and a four carbon chain with a methoxy group on the first carbon, a chlorine atom on the second carbon, and a chlorine atom on the third carbon. ### Q46 Numerical 1.5gm mixture of SiO₂ and Fe₂O₃ on very strong heating leave a residue weighting 1.46gm. The reaction responsible for loss of weight is: Fe₂O₃(s) → Fe₃O₄(s) + O₂(g) What is the percentage by mass of Fe in original sample :- ### Q47. Numerical Consider the following reversible reaction: NO + NO₃ → 2NO₂ If 1. Omol of NO is mixed with 3. Omol of NO₃, 'x' mole of NO₂ is produced at equilibrium. If 2. Omol of NO is added further, 'x' mol of NO₂ is further produced. What is the value of equilibrium constant? ### Q48 Numerical A solution containing 8.0 g of nicotine in 92 g of water freezes 0. 925 degrees below the normal freezing point of water. If the molal freezing point depression constant, K_f = 1.85°C mol^-1, then the molar mass of nicotine is: (mark answer to nearest integer) ### Q49 Numerical For the following electrochemical cell at 298 K, Pt(s)|H₂(g, 1 bar)|H⁺(aq, 1M)||M⁴⁺(aq), M²⁺ (aq)|Pt(s) E_cell = 0.092V when [M²⁺ (aq)] / [M⁴⁺(aq)] = 10^x Given: E⁰_{M⁴⁺|M²⁺} = 0.151V; 2.303 RT / F = 0.059 V The value of x is (nearest integer)..... ### Q50 Numerical There are some isomeric amines containing only one N atom. Each one of which forms a chloride salt on treatment with HCl containing 32.42% chlorine. None of them decolorizes Br₂ water. How many of them does not give carbyl amine test? ### Q51 Single Correct Let f : R → R be a function defined by f(x) = -x³ – 3x² - 6x + 1. Number of integers in the solution set of a satisfying the inequality f(f(x³ + f(x))) ≥ f(f(f(x) - x³)) is? * A 3 * B 4 * C 5 * D 6 ### Q52 Single Correct The system of simultaneous equations kx + 2y - z = 1, (k − 1)y – 2z = 2 and (k + 2)z = 3 has a unique solution, if k equals * A -2 * B -1 * C 0 * D 1 ### Q53 Single Correct If f(x) = cosx - ∫₀^x (x-t) f(t)dt, then f'(x) + f(x) is equal to * A - cos x * B - sin x * C ∫₀^x (x-t) f(t)dt * D 0 ### Q54 Single Correct If z is a complex number such that z + i|z| = iz + 1, then |z| is * A 4 * B 2 * C 1 * D 0 ### Q55 Single Correct If α₁, β₁, γ₁, δ₁ are the roots of the equation ax⁴ + bx³ + cx² + dx + e = 0 and α₂, β₂, γ₂, δ₂ are the roots of the equation ex⁴ + dx³ + cx² + bx + a = 0 such that 0 < α₁ < β₁ < γ₁ < δ₁,0 < α₂ < β₂ < γ₂ < δ₂ α₁ - δ₂ = β₁ - γ₂; γ₁ - β₂ = δ₁ - α₂ = 4, then a+b+c+d+e = * A 10 * B 12 * C 6 * D 8 ### Q56 Single Correct If the area bounded by f(x) = tan³x + tanx from x = 0 to x = π/4 is k square units, then the maximum value of g(x) = ksin√x is (√x∈ [0, π/4]) * A 2 * B 1/2√2 * C 4 * D 8 ### Q57 Single Correct Let the function defined as f(x) = { sin[x²]/x²-3x-18 + ax³ + b, 0 ≤ x ≤ 1 { 2cosx + tan^-1x, 1 < x ≤ 2 is a differentiable function in the interval (0, 2), then the value of [a + b] equals, ( [•] represents greatest integer function) * A 0 * B -1 * C -2 * D 1 ### Q58 Single Correct 4 cards are drawn from a well shuffled pack of 52 cards without replacement. If the fourth card is a king, then the chance that the first 3 cards are also king is 1 / 20820+a, then a is equal to * A 4 * B 1 * C 2 * D 5 ### Q59 Single Correct There are 3 identical black balls, 4 identical white balls and 2 identical red balls. The number of ways they can be arranged in a row so that at least one ball separates the balls of the same colour is * A 1210 * B 1212 * C 1244 * D 1254 ### Q60. Single Correct If the eccentricity of the hyperbola x² - y²sec²θ = 5 is √3 times the eccentricity of the ellipse x²sec²θ+ y² = 25, then smallest positive value of θ is π / p, where twice the value of ' p' is * A 8 * B 12 * C 16 * D 24 ### Q61 Single Correct An equilateral triangle's sides increase at the rate of 2 cm/sec. If the area of its incircle increases at a rate of k cm²/sec (when the length of the side is 6/π cm), then the value of k is * A 1 * B 4 * C 2 * D 3 ### Q62 Single Correct 5 5 If Σ_(i=1) ^5 (x_i - 6) = 5 and Σ_(i=1) ^5 (x_i - 6)^2 = 25, then the standard deviation of observations 3x₁ + 2, 3x₂+2, 3x₃ +2, 3x₄ + 2 and