Practice Questions

Q17.A cell of emf 90 V is connected across series combination of two resistors each of 100 Ω resistance. A voltmeter of resistance 400 Ω is used to measure the potential difference across each resistor. The reading of the voltmeter will be: (1) 40 V (2) 45 V (3) 80 V (4) 90 V

Q17.In the given circuit. C1 = 2μF, C2 = 0. 2μF, C3 = 2μF, C4 = 4μF, C5 = 2μF, C6 = 2μF. The charge stored on capacitor C4 is ______ μC. JEE Main 2023 (11 Apr Shift 2) JEE Main Previous Year Paper

Q17.An electric dipole of dipole moment is 6. 0 × 10−6 C m placed in a uniform electric field of 1. 5 × 103 N C−1 in such a way that dipole moment is along electric field. The work done in rotating dipole by 180° in this field will be_______ mJ.

Q18.The number density of free electrons in copper is nearly 8 × 1028 m−3 . A copper wire has its area of cross- section = 2 × 10−6 m2 and is carrying a current of 3. 2 A . The drift speed of the electrons is _____ ×10−6 m s−1 .

Q18.If the potential difference between B and D is zero, the value of x is n1 Ω. The value of n is ______.

Q18.A capacitor has capacitance 5 µF when its parallel plates are separated by air medium of thickness d. A slab of material of dielectric constant 1. 5 having area equal to that of plates but thickness d2 is inserted between the plates. Capacitance of the capacitor in the presence of slab will be ______ µF .

Q18.A potential V0 is applied across a uniform wire of resistance R. The power dissipation is P1. The wire is then cut into two equal halves and a potential of V0 is applied across the length of each half. The total power dissipation across two wires is P2. The ratio of P2 : P1 is √x : 1. The value of x is _____.

Q18.In the given circuit, the equivalent resistance between the terminal A and B is ____ Ω

Q18.A null point is found at 200 cm in potentiometer when cell in secondary circuit is shunted by 5 Ω . When a resistance of 15 Ω is used for shunting null point moves to 300 cm . The internal resistance of the cell is ______ Ω .

Q19.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Photodiodes are preferably operated in reverse bias condition for light intensity measurement. Reason R: The current in the forward bias is more than the current in the reverse bias for a 𝑝- 𝑛 junction diode. In the light of the above statement, choose the correct answer from the options given below : JEE Main 2023 (24 Jan Shift 1) JEE Main Previous Year Paper (1) A is false but R is true (2) Both A and R are true but R is NOT the correct explanation of A (3) A is true but R is false (4) Both A and R are true and R is the correct explanation of A

Q19.Two identical cells each of emf 1. 5 V are connected in series across a 10 Ω resistance. An ideal voltmeter connected across 10 Ω resistance reads 1. 5 V . The internal resistance of each cell is _____ Ω.

Q19.When a resistance of 5 Ω is shunted with a moving coil galvanometer, it shows a full scale deflection for a current of 250 mA, however when 1050 Ω resistance is connected with it in series, it gives full scale deflection for 25 volt. The resistance of galvanometer is _________Ω.

Q19.A current of 2 A flows through a wire of cross-sectional area 25. 0 mm2 . The number of free electrons in a cubic meter are 2. 0 × 1028 . The drift velocity of the electrons is _____ ×10−6 ms−1 (given, charge on electron = 1. 6 × 10−19C).

Q19.A long solenoid is formed by winding 70 turns cm−1 . If 2. 0 A current flows, then the magnetic field produced inside the solenoid is ______________. (µ0 = 4π × 10–7 T m A–1) (1) 1232 × 10–4 T (2) 176 × 10–4 T (3) 352 × 10–4 T (4) 88 × 10–4 T

Q19.Given below are two statements: Statement I : The diamagnetic property depends on temperature. Statement II : The induced magnetic dipole moment in a diamagnetic sample is always opposite to the magnetising field. In the light of given statements, choose the correct answer from the options given below (1) Both Statement I and Statement II are False (2) Statement I is incorrect but Statement II is true (3) Statement I is correct but Statement II is false (4) Both Statement I and Statement II are true

Q19.In the given circuit the value of I1+I3 is: I2

Q19.For the given circuit, in the steady state, |VB −VD| = _____ V .

Q20.The ratio of magnetic field at the centre of a current carrying coil of radius r to the magnetic field at distance r from the centre of coil on its axis is √x : 1 . The value of x is _____.

Q20.In an experiment with vernier callipers of least count 0 . 1 mm, when two jaws are joined together the zero of vernier scale lies right to the zero of the main scale and 6th division of vernier scale coincides with the main scale division. While measuring the diameter of a spherical bob, the zero of vernier scale lies in between 3 . 2 cm and 3 . 3 cm marks and 4th division of vernier scale coincides with the main scale division. The diameter of bob is measured as (1) 3 . 22 cm (2) 3 . 18 cm (3) 3 . 26 cm (4) 3 . 25 cm JEE Main 2023 (10 Apr Shift 2) JEE Main Previous Year Paper

Q20.As shown in the figure the voltmeter reads 2 V across 5 Ω resistor. The resistance of the voltmeter is _____ Ω

Q20.Two cells are connected between points A and B as shown. Cell 1 has emf of 12 V and internal resistance of 3 Ω. Cell 2 has emf of 6 V and internal resistance of 6 Ω. An external resistor R of 4 Ω is connected across A and B. The current flowing through R will be ______ A .

Q21.In the given figure, an inductor and resistor are connected in series with a battery of emf E volt. Ea2b J s−1 represents the maximum rate at which the energy is stored in the magnetic field (inductor). The numerical value of b will be _____. a JEE Main 2023 (13 Apr Shift 1) JEE Main Previous Year Paper

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 projectile fired at 30° to the ground is observed to be at same height at time 3 s and 5 s after projection, during its flight. The speed of projection of the projectile is m s-1. (Given 𝑔= 10 m s-2) →

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 _____.