Practice Questions

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

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

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.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.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 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.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]

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 work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV , respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of (1) Both Cs and Li (2) Neither Cs nor Li (3) Cs only (4) Li only

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

Q41. A tube of length L is shown in the figure. The radius of cross section at the point (1) is 2 cm and at the point (2) is 1 cm , respectively. If the velocity of water entering at point (1) is 2 m/s, then velocity of water leaving the point (2) will be (1) 4 m/s (2) 2 m/s (3) 6 m/s (4) 8 m/s

Q42.The pair of physical quantities not having same dimensions is : (1) Pressure and Young's modulus (2) Surface tension and impulse (3) Torque and energy (4) Angular momentum and Planck's constant

Q42.A solid sphere is rolling without slipping on a horizontal plane. The ratio of the linear kinetic energy of the centre of mass of the sphere and rotational kinetic energy is : (1) 3 (2) 4 4 3 (3) 5 (4) 2 2 5

Q42.The ratio of vapour densities of two gases at the same temperature is 4 , then the ratio of r.m.s. velocities will 25 be: (1) 25 (2) 2 4 5 (3) 5 (4) 4 2 25

Q42.A parallel plate capacitor was made with two rectangular plates, each with a length of l = 3 cm and breath of b = 1 cm . The distance between the plates is 3μ m . Out of the following, which are the ways to increase the capacitance by a factor of 10 ? A. l = 30 cm, b = 1 cm, d = 1μ m B. l = 3 cm, b = 1 cm, d = 30μ m C. l = 6 cm, b = 5 cm, d = 3μ m D. l = 1 cm, b = 1 cm, d = 10μ m E. l = 5 cm, b = 2 cm, d = 1μ m Choose the correct answer from the options given below: 2025 (24 Jan Shift 1) JEE Main Previous Year Paper (1) A only (2) C only (3) B and D only (4) C and E only

Q43.Match List - I with List - II. List - I List - II (A) Magnetic induction (I) Ampere meter 2 (B) Magnetic intensity (II) Weber (C) Magnetic flux (III) Gauss (D) Magnetic moment (IV) Ampere/meter (1) (A)-(I), (B)-(II), (C)-(III), (D)-(IV) (2) (A)-(III), (B)-(IV), (C)-(I), (D)-(II) (3) (A)-(III), (B)-(II), (C)-(I), (D)-(IV) (4) (A)-(III), (B)-(IV), (C)-(II), (D)-(I)

Q43.Consider I1 and I2 are the currents flowing simultaneously in two nearby coils 1 & 2, respectively. If L1 = self inductance of coil 1, M12 = mutual inductance of coil 1 with respect to coil 2, then the value of induced emf in coil 1 will be Options (1) ε1 = −L1 dI2dt −M12 dI1dt (2) ε1 = −L1 dI1dt −M12 dI2dt (3) ε1 = −L1 dI1dt −M12 dI1dt (4) ε1 = −L1 dI1dt + M12 dI2dt

Q43.Consider a parallel plate capacitor of area A (of each plate) and separation 'd' between the plates. If E is the electric field and ε0 is the permittivity of free space between the plates, then potential energy stored in the capacitor is (1) ε0E2Ad (2) 12 ε0E2Ad (3) 1 4 ε0E2Ad (4) 34 ε0E2Ad

Q44.A point charge causes an electric flux of −2 × 104Nm2C−1 to pass through a spherical Gaussian surface of 8.0 cm radius, centred on the charge. The value of the point charge is : (Given ϵ0 = 8.85 × 10−12C2 N−1 m−2 ) (1) 15.7 × 10−8C (2) 17.7 × 10−8C (3) −15.7 × 10−8C (4) −17.7 × 10−8C

Q45.For an experimental expression y = 32.3×112527.4 , where all the digits are significant. Then to report the value of y we should write (1) y = 1326.19 (2) y = 1330 (3) y = 1326.186 (4) y = 1326.2

Q45.A force F = 2^i + b^j + ^k is applied on a particle and it undergoes a displacement ^i −2^j −^k. What will be the value of b, if work done on the particle is zero. (1) 0 (2) 1 2 (3) 2 (4) 1 3

Q45.In photoelectric effect an em-wave is incident on a metal surface and electrons are ejected from the surface. If the work function of the metal is 2.14 eV and stopping potential is 2 V , what is the wavelength of the em- wave ? (Given hc = 1242eVnm where h is the Planck's constant and c is the speed of light in vaccum.) 2025 (23 Jan Shift 2) JEE Main Previous Year Paper (1) 300 nm (2) 400 nm (3) 600 nm (4) 200 nm

Q51.For hydrogen atom, the orbital/s with lowest energy is/are : (A) 4 s (B) 3px (C) 3 dx2−y2 (D) 3 dz2 (E) 4pz Choose the correct answer from the options given below : (1) (B), (C) and (D) only (2) (A) and (E) only (3) (A) only (4) (B) only

Q51.Radius of the first excited state of Helium ion is given as : a0 → radius of first stationary state of hydrogen atom. (1) r = 4a0 (2) r = 2a0 (3) r = a02 (4) r = a04