Practice Questions

Q32.Given are statements for certain thermodynamic variables, (A) Internal energy, volume (V) and mass (M) are extensive variables. (B) Pressure (P), temperature (T) and density ( ρ ) are intensive variables. (C) Volume (V), temperature (T) and density ( ρ ) are intensive variables. (D) Mass (M), temperature (T) and internal energy are extensive variables. Choose the correct answer from the options given below : (1) (B) and (C) Only (2) (C) and (D) Only (3) (D) and (A) Only (4) (A) and (B) Only

Q33.What is the relative decrease in focal length of a lens for an increase in optical power by 0.1 D from 2.5D ? ['D' stands for dioptre] (1) 0.01 (2) 0.04 (3) 0.40 (4) 0.1

Q33.Which of the following circuits represents a forward biased diode? Choose the correct answer from the options given below : (1) (A) and (D) only (2) (B), (D) and (E) only (3) (C) and (E) only (4) (B), (C) and (E) only

Q33.A concave mirror of focal length f in air is dipped in a liquid of refractive index μ. Its focal length in the liquid will be: (1) μf (2) f (3) f (4) f (μ−1) μ 2025 (23 Jan Shift 2) JEE Main Previous Year Paper

Q34.A small uncharged conducting sphere is placed in contact with an identical sphere but having 4 × 10−8C charge and then removed to a distance such that the force of repulsion between them is 9 × 10−3 N . The distance between them is (Take 1 as 9 × 109inSI units) 4πϵo (1) 3 cm (2) 2 cm (3) 4 cm (4) 1 cm 2025 (24 Jan Shift 2) JEE Main Previous Year Paper

Q34. What is the current through the battery in the circuit shown below (1) 1.5 A (2) 0.5 A (3) 0.25 A (4) 1.0 A Q35.5 The refractive index of the material of a glass prism is √3. The angle of minimum deviation is equal to the angle of the prism. What is the angle of the prism? (1) 60∘ (2) 58∘ (3) 48∘ (4) 50∘

Q34.A force F = α + βx2 acts on an object in the x -direction. The work done by the force is 5 J when the object is displaced by 1 m . If the constant α = 1 N then β will be (1) 15 N/m2 (2) 12 N/m2 (3) 8 N/m2 (4) 10 N/m2

Q34.A 400 g solid cube having an edge of length 10 cm floats in water. How much volume of the cube is outside the water ? (Given : density of water = 1000 kg m−3 ) (1) 1400 cm3 (2) 600 cm3 (3) 4000 cm3 (4) 400 cm3

Q35.The number of spectral lines emitted by atomic hydrogen that is in the 4th energy level, is (1) 3 (2) 1 (3) 6 (4) 0

Q36.A wire of resistance R is bent into an equilateral triangle and an identical wire is bent into a square. The ratio of resistance between the two end points of an edge of the triangle to that of the square is Options (1) 8/9 (2) 27/32 (3) 32/27 (4) 9/8

Q36. LIST-I LIST-II A. Pressure varies inversely with volume of an ideal gas. I. Adiabatic process B. Heat absorbed goes partly to increase internal energy and partly to do work. II. Isochoric process C. Heat is neither absorbed nor released by a system. III. Isothermal process D. No work is done on or by a gas. IV. Isobaric process (1) A-III, B-IV, C-I, D-II (2) A-I, B-IV, C-II, D-III (3) A-III, B-I, C-IV, D-II (4) A-I, B-III, C-II, D-IV

Q37.If B is magnetic field and μ0 is permeability of free space, then the dimensions of (B/μ0) is (1) ML2 T−2 A−1 (2) MT−2 A−1 (3) L−1 A (4) LT−2 A−1

Q37.Earth has mass 8 times and radius 2 times that of a planet. If the escape velocity from the earth is 11.2 km/s, the escape velocity in km/s from the planet will be : (1) 2.8 (2) 11.2 (3) 5.6 (4) 8.4 → sin [ω (t −zc )] (S.I. Units). The

Q38. For the circuit shown above, equivalent GATE is : (1) OR gate (2) NAND gate (3) NOT gate (4) AND gate 2025 (29 Jan Shift 1) JEE Main Previous Year Paper

Q38.A plane electromagnetic wave of frequency 20 MHz travels in free space along the +x direction. At a particular point in space and time, the electric field vector of the wave is Ey = 9.3Vm−1 . Then, the magnetic field vector of the wave at that point is (1) Bz = 6.2 × 10−8 T (2) Bz = 3.1 × 10−8 T (3) Bz = 1.55 × 10−8 T (4) Bz = 9.3 × 10−8 T

Q39.The kinetic energy of translation of the molecules in 50 g of CO2 gas at 17∘C is (1) 4205.5 J (2) 4102.8 J (3) 3582.7 J (4) 3986.3 J

Q39.The equation of a transverse wave travelling along a string is y(x, t) = 4.0 sin [20 × 10−3x + 600t]mm , where x is in mm and t is in second. The velocity of the wave is : 2025 (23 Jan Shift 2) JEE Main Previous Year Paper (1) −60 m/s (2) −30 m/s (3) +30 m/s (4) +60 m/s

Q39.A plane electromagnetic wave propagates along the +x direction in free space. The components of the electric field, →E and magnetic field, →B vectors associated with the wave in Cartesian frame are (1) Ex, By (2) Ey, Bz (3) Ez, By (4) Ey, Bx

Q39.The expression given below shows the variation of velocity (v) with time (t), v = At2 + C+tBt . The dimension of ABC is : (1) [M0 L1 T−3] (2) [M0 L2 T−2] (3) [M0 L1 T−2] (4) [M0 L2 T−3]

Q39.Arrange the following in the ascending order of wavelength (λ) : (A) Microwaves (λ1) (B) Ultraviolet rays (λ2) (C) Infrared rays (λ3) (D) X-rays (λ4) Choose the most appropriate answer from the options given below : (1) λ4 < λ3 < λ2 < λ1 (2) λ3 < λ4 < λ2 < λ1 (3) λ4 < λ3 < λ1 < λ2 (4) λ4 < λ2 < λ3 < λ1

Q39.A series LCR circuit is connected to an alternating source of emf E. The current amplitude at resonant frequency is I0 . If the value of resistance R becomes twice of its initial value then amplitude of current at resonance will be (1) 2I0 (2) I0 (3) I0 (4) I0 2 √2

Q40.Which of the following phenomena can not be explained by wave theory of light? 2025 (28 Jan Shift 2) JEE Main Previous Year Paper (1) Compton effect (2) Refraction of light (3) Reflection of light (4) Diffraction of light

Q40.Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The binding energy per nucleon is found to be practically independent of the atomic number A, for nuclei with mass numbers between 30 and 170. Reason (R): Nuclear force is long range. In the light of the above statements, choose the correct answer from the options given below : (1) (A) is true but (R) is false (2) (A) is false but (R) is true (3) Both (A) and (R) are true and (R) is the correct (4) Both (A) and (R) are true but (R) is NOT the explanation of (A) correct explanation of (A)

Q40.The workdone in an adiabatic change in an ideal gas depends upon only : (1) change in its temperature (2) change in its volume (3) change in its pressure (4) change in its specific heat

Q40.The energy E and momentum p of a moving body of mass m are related by some equation. Given that c represents the speed of light, identify the correct equation (1) E2 = pc2 + m2c2 (2) E2 = p2c2 + m2c2 (3) E2 = pc2 + m2c4 (4) E2 = p2c2 + m2c4