Practice Questions

Q12.A current of 200 μA deflects the coil of a moving coil galvanometer through 60°. The current to cause 𝜋 deflection through radian is 10 (1) 30 μA (2) 120 μA (3) 60 μA (4) 180 μA

Q12.A capacitor of capacitance 100 μF is charged to a potential of 12 V and connected to a 6. 4 mH inductor to produce oscillations. The maximum current in the circuit would be : (1) 3. 2 A (2) 1. 5 A (3) 2. 0 A (4) 1. 2 A

Q12.The reading in the ideal voltmeter 𝑉 shown in the given circuit diagram is: (1) 5 V (2) 10 V (3) 0 V (4) 3 V

Q12.In a metre-bridge when a resistance in the left gap is 2 Ω and unknown resistance in the right gap, the balance length is found to be 40 cm . On shunting the unknown resistance with 2 Ω, the balance length changes by: (1) 22 . 5 cm (2) 20 cm (3) 62 . 5 cm (4) 65 cm JEE Main 2024 (01 Feb Shift 2) JEE Main Previous Year Paper

Q12.An electric bulb rated 50 W −200 V is connected across a 100 V supply. The power dissipation of the bulb is: (1) 25 W (2) 12.5 W (3) 50 W (4) 100 W

Q12.If the collision frequency of hydrogen molecules in a closed chamber at 27∘C is Z, then the collision frequency of the same system at 127∘C is : (1) √3 2 z (2) √32 Z (3) 3 4 Z (4) 34 Z

Q12.The ratio of heat dissipated per second through the resistance 5Ω and 10Ω in the circuit given below is : (1) 1 : 2 (2) 2 : 1 (3) 4 : 1 (4) 1 : 1 −

Q12.The value of unknown resistance (x) for which the potential difference between B and D will be zero in the arrangement shown, is : (1) 3Ω (2) 42Ω (3) 9Ω (4) 6Ω

Q12. Match List-I with List-II : Choose the correct answer from the options given below : (1) (A)-(IV), (B)-(I), (C)-(III), (D)-(II) (2) (A)-(I), (B)-(III), (C)-(II), (D)-(IV) (3) (A)-(III), (B)-(IV), (C)- (I), (D)-(II) (4) (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

Q13.A galvanometer has a resistance of 50 𝛺 and it allows maximum current of 5 mA. It can be converted into voltmeter to measure upto 100 V by connecting in series a resistor of resistance. (1) 5975 𝛺 (2) 20050 𝛺 (3) 19950 𝛺 (4) 19500 𝛺

Q13.The magnetic moment of a bar magnet is 0.5Am2 . It is suspended in a uniform magnetic field of 8 × 10−2 T. The work done in rotating it from its most stable to most unstable position is: (1) 8 × 10−2 J (2) 4 × 10−2 J (3) Zero (4) 16 × 10−2 J JEE Main 2024 (04 Apr Shift 2) JEE Main Previous Year Paper

Q13.Three voltmeters, all having different internal resistances are joined as shown in figure. When some potential difference is applied across A and B, their readings are 𝑉1, 𝑉2 and 𝑉3. Choose the correct option. JEE Main 2024 (27 Jan Shift 2) JEE Main Previous Year Paper (1) 𝑉1 = 𝑉2 (2) 𝑉1 ≠𝑉3 - 𝑉2 (3) 𝑉1 + 𝑉2 > 𝑉3 (4) 𝑉1 + 𝑉2 = 𝑉3

Q13.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 and 2a from axis of the wire is : 2 (1) 1 : 4 (2) 1 : 1 (3) 3 : 4 (4) 4 : 1

Q13.Two particles X and Y having equal charges are being accelerated through the same potential difference. Thereafter, they enter normally in a region of uniform magnetic field and describes circular paths of radii R1 and R2 respectively. The mass ratio of X and Y is : (1) R2 2 (2) R1 2 ( R1 ) ( R2 ) (3) ( R2R1 ) (4) ( R1R2 ) JEE Main 2024 (29 Jan Shift 2) JEE Main Previous Year Paper

Q13.The electric current through a wire varies with time as I = I0 + βt, where I0 = 20 A and β = 3 A s−1 . The amount of electric charge crossed through a section of the wire in 20 s is: JEE Main 2024 (29 Jan Shift 1) JEE Main Previous Year Paper (1) 80 C (2) 1000 C (3) 800 C (4) 1600 C

Q13.An element Δl = Δx^i is placed at the origin and carries a large current I = 10 A. The magnetic field on the y- axis at a distance of 0.5 m from the elements Δx of 1 cm length is: JEE Main 2024 (06 Apr Shift 1) JEE Main Previous Year Paper (1) 4 × 10−8 T (2) 10 × 10−8 T (3) 8 × 10−8 T (4) 12 × 10−8 T

Q13.A proton moving with a constant velocity passes through a region of space without any change in its velocity. → → If E and B represent the electric and magnetic fields respectively, then the region of space may have : (A) E = 0, B = 0; (B) E = 0, B ≠0; (C) E ≠0, B = 0; (D) E ≠0, B ≠0 Choose the most appropriate answer from the options given below : (1) (A), (B) and (C) only (2) (A), (C) and (D) only (3) (A), (B) and (D) only (4) (B), (C) and (D) only

Q13.In a coil, the current changes from −2 A to +2 A in 0.2 s and induces an emf of 0.1 V. The self inductance of the coil is : (1) 4mH (2) 1mH (3) 5mH (4) 2.5mH

Q13.The electrostatic force → and magnetic force acting on a charge q moving with velocity v can be (→F2) (F1) written : (1) →F1 = q →E, →F2 = q(→V × →B) (2) →F1 = q →B, →F2 = q(→B × →V ) (3) →F1 = q →E, →F2 = q(→B × →V ) (4) →F1 = q →V ⋅→E, →F2 = q(→B ⋅→V )

Q13.In an ammeter, 5% of the main current passes through the galvanometer. If resistance of the galvanometer is G, the resistance of ammeter will be: G G (1) (2) 20 199 (3) 199 G (4) 200 G

Q13.Match List I with List II List I List II 1 A. Gauss’s law of magnetostatics i. ∮ →𝐸· d→𝑎= ∫𝜌d𝑉 𝜀0 B. Faraday’s law of electro magnetic induction ii. ∮ →𝐵· d→𝑎= 0 → → -d → C. Ampere’s law iii. ∮ 𝐸· d 𝑙= 𝐵· d →𝑎 d𝑡∫ D. Gauss’s law of electrostatics iv. ∮ →𝐵· d →𝑙= 𝜇0𝐼 Choose the correct answer from the options given below: (1) A-I, B-III, C-IV, D-II (2) A-III, B-IV, C-I, D-II (3) A-IV, B-II, C-III, D-I (4) A-II, B-III, C-IV, D-I

Q13.Two charges 𝑞 and 3𝑞 are separated by a distance ‘𝑟’ in air. At a distance 𝑥 from charge 𝑞, the resultant electric field is zero. The value of 𝑥 is : (1) ( 1 + √3 ) (2) 𝑟 𝑟 3 ( 1 + √3 ) 𝑟 (3) (4) 𝑟( 1 + √3 ) ( 1 + √3 ) JEE Main 2024 (31 Jan Shift 1) JEE Main Previous Year Paper

Q13.The magnetic field in a plane electromagnetic wave is By = (3.5 × 10−7) sin (1.5 × 103x + 0.5 × 1011t)T. The corresponding electric field will be : (1) Ey = 10.5 sin (1.5 × 103x + 0.5 × 1011t)Vm−1 (2) Ez = 1.17 sin (1.5 × 103x + 0.5 × 1011t)Vm−1 (3) Ey = 1.17 sin (1.5 × 103x + 0.5 × 1011t)Vm−1 (4) Ez = 105 sin (1.5 × 103x + 0.5 × 1011t)Vm−1

Q13.A uniform magnetic field of 2 × 10-3 T acts along positive Y-direction. A rectangular loop of sides 20 cm and 10 cm with current of 5 A is in Y-Z plane. The current is in anticlockwise sense with reference to negative X axis. Magnitude and direction of the torque is : (1) 2 × 10-4 N m along positive Z –direction (2) 2 × 10-4 N m along negative Z-direction (3) 2 × 10-4 N m along positive X-direction (4) 2 × 10-4 N m along positive Y-direction π

Q13.In the given figure R1 = 10Ω, R2 = 8Ω, R3 = 4Ω and R4 = 8Ω . Battery is ideal with emf 12 V . Equivalent resistant of the circuit and current supplied by battery are respectively : (1) 10.5Ω and 1.14 A (2) 12Ω and 1 A (3) 10.5Ω and 1 A (4) 12Ω and 11.4 A