Practice Questions

Q20.A single turn current loop in the shape of a right angle triangle with sides 5 cm, 12 cm, 13 cm is carrying a current of 2 A . The loop is in a uniform magnetic field of magnitude 0. 75 T whose direction is parallel to the current in the 13 cm side of the loop. The magnitude of the magnetic force on the 5 cm side will be 130x N . The value of x is _______.

Q20.A current carrying rectangular loop PQRS is made of uniform wire. The length PR = QS = 5 cm and PQ = RS = 100 cm. If ammeter current reading changes from I to 2I , the ratio of : f PQ)2I is: magnetic forces per unit length on the wire PQ due to wire RS in the two cases respectively (f PQI JEE Main 2023 (30 Jan Shift 2) JEE Main Previous Year Paper (1) 1 : 2 (2) 1 : 4 (3) 1 : 5 (4) 1 : 3

Q20.The amplitude of 15sin ( 1000π𝑡) is modulated by 10sin ( 4π𝑡) signal. The amplitude modulated signal contains frequency (ies) of ( 𝐴) 500 Hz ( 𝐵) 2 Hz ( 𝐶) 250 Hz ( 𝐷) 498 Hz ( 𝐸) 502 Hz Choose the correct answer from the options given below: (1) A only (2) A, D and E only (3) B only (4) A and B only

Q20.To radiate EM signal of wavelength 𝜆 with high efficiency, the antennas should have a minimum size equal to: (1) 2𝜆 (2) 𝜆 2 (3) 𝜆 (4) 𝜆 4

Q20.A carrier wave of amplitude 15 V is modulated by a sinusoidal base band signal of amplitude 3 V. The ratio of maximum amplitude to minimum amplitude in an amplitude modulated wave is 3 (1) 2 (2) 2 (3) 1 (4) 5

Q20.A compass needle oscillates 20 times per minute at a place where the dip is 30o and 30 times per minute where the dip is 60o . The ratio of total magnetic field due to the earth at two places respectively is 4 . The value of √x x is

Q21.Vectors 𝑎 ^𝑖+ 𝑏 ^𝑗+ ^𝑘 and 2 ^𝑖- 3 ^𝑗+ 4 ^𝑘 are perpendicular to each other when 3𝑎+ 2𝑏= 7, the ratio of 𝑎 to 𝑏 is 𝑥 2. The value of 𝑥 is _____.

Q21.In an LC oscillator, if values of inductance and capacitance become twice and eight times, respectively, then the resonant frequency of oscillator becomes x times its initial resonant frequency ω0 . The value of x is: (1) 1/4 (2) 16 (3) 1/16 (4) 4

Q21.A charge particle moving in magnetic field B, has the components of velocity along B as well as perpendicular to B. The path of the charge particle will be (1) helical path with the axis perpendicular to the (2) helical path with the axis along magnetic field B direction of magnetic field B (3) circular path (4) straight along the direction of magnetic field B

Q21.A car accelerates from rest of 𝑢 m s-1. The energy spent in this process is 𝐸 J. The energy required to accelerate the car from 𝑢 m s-1 to 2𝑢 m s-1 is 𝑛𝐸 J. The value of 𝑛 is _____. JEE Main 2023 (13 Apr Shift 2) JEE Main Previous Year Paper

Q21.An alternating voltage source V = 260 sin(628t) is connected across a pure inductor of 5 mH . Inductive reactance in the circuit is: (1) 3. 14Ω (2) 6. 28Ω (3) 0. 5Ω (4) 0. 318Ω

Q21.An electron is allowed to move with constant velocity along the axis of current carrying straight solenoid. (A) The electron will experience magnetic force along the axis of the solenoid. (B) The electron will not experience magnetic force. (C) The electron will continue to move along the axis of the solenoid. (D) The electron will be accelerated along the axis of the solenoid. (E) The electron will follow parabolic path-inside the solenoid. Choose the correct answer from the option given below: (1) B, C and D only (2) A and D only (3) B and C only (4) B and E only

Q21.An emf of 0. 08 V is induced in a metal rod of length 10 cm held normal to a uniform magnetic field of 0. 4 T, when move with a velocity of: (1) 0. 5 m s−1 (2) 20 m s−1 (3) 3. 2 m s−1 (4) 2 m s−1

Q21.The length of a metallic wire is increased by 20% and its area of cross-section is reduced by 4 % . The percentage change in resistance of the metallic wire is ________ .

Q21.A block of mass 10 kg is moving along x-axis under the action of force F = 5x N . The work done by the force in moving the block from x = 2 m to 4 m will be _______ J.

Q21.A small particle moves to position 5 ^𝑖- 2 ^𝑗+ ^𝑘 from its initial position 2 ^𝑖+ 3 ^𝑗- 4 ^𝑘 under the action of force 5 ^𝑖+ 2 ^𝑗+ 7 ^𝑘 N. The value of work done will be ______ J.

Q22.In the given circuit, rms value of current (Irms) through the resistor R is : (1) 2 A (2) 21 A (3) 20 A (4) 2√2 A

Q22.A solid cylinder is released from rest from the top of an inclined plane of inclination 30° and length 60 cm. If the cylinder rolls without slipping, its speed upon reaching the bottom of the inclined plane is ______ m s-1. (Given 𝑔= 10 m s-2)

Q22.An inductor of inductance 2 μH is connected in series with a resistance, a variable capacitor and an AC source of frequency 7 kHz. The value of capacitance for which maximum current is drawn into the circuit is x1 F , where the value of x is ______. (Take π = 227 )

Q22.Which of the following are true? A. Speed of light in vacuum is dependent on the direction of propagation. B. Speed of light in a medium is independent of the wavelength of light. C. The speed of light is independent of the motion of the source. D. The speed of light in a medium is independent of intensity. Choose the correct answer from the question given below : (1) A and C only (2) B and D only (3) B and C only (4) C and D only

Q23.Match List I and List II List I List II A Microwaves I Physiotherapy B UV rays II Treatment of cancer JEE Main 2023 (31 Jan Shift 2) JEE Main Previous Year Paper C Infra-red rays III Lasik eye surgery D X-rays IV Aircraft navigation Choose the correct answer from the option given below: (1) A-II, B-IV, C-III, D-I (2) A-IV, B-I, C-II, D-III (3) A-IV, B-III, C-I, D-II (4) A-III, B-II, C-I, D-IV

Q23.All electromagnetic wave is transporting energy in the negative z direction. At a certain point and certain time the direction of electric field of the wave is along positive y direction. What will be the direction of the magnetic field of the wave at that point and instant? JEE Main 2023 (25 Jan Shift 1) JEE Main Previous Year Paper (1) Positive direction of x (2) Positive direction of z (3) Negative direction of x (4) Negative direction of y

Q23.A capacitor of capacitance 150. 0 μF is connected to an alternating source of emf given by E = 36 sin(120πt) V. The maximum value of current in the circuit is approximately equal to: (1) 2 A (2) √2 A (3) 2√2 A (4) 1 A √2 → →

Q23.A vessel of depth d is half filled with oil of refractive index n1 and the other half is filled with water of refractive index n2. The apparent depth of this vessel when viewed from above will be- (1) 2d(n1+n2) (2) d(n1+n2) n1+n2 2n1n2 (3) dn1n2 (4) dn1n2 2(n1+n2) (n1+n2)

Q23.The ratio of average electric energy density and total average energy density of electromagnetic wave is: (1) 2 (2) 1 (3) 3 (4) 21