Class XII Physics Electromagnetic Induction 4

When the current changes from +2 A to −2 A in 0.05 second, an e.m.f. of 8 V is induced in a coil. The coefficient of self-induction of the coil is

One conducting U tube can slide inside another as shown in figure, maintaining electrical contacts between the tubes. The magnetic field B is perpendicular to the plane of the figure. If each tube moves towards the other at a constant speed V, then the emf induced in the circuit in terms of B, and V where is the width of each tube will be

A rectangular loop has a sliding connector PQ of length and resistance RΩ and it is moving with a speed v as shown. The set–up is placed in a uniform magnetic field going into the plane of the paper. The three current I₁, I₂ and I are

In an AC generator, a coil with N turns, all of the same area A and total resistance R, rotates with frequency ω in a magnetic field B. The maximum value of emf generated in the coil is

A metal conductor of length 1 m rotates vertically about one of its ends at angular velocity 5 radians per second. If the horizontal component of earth’s magnetic field is 0.2 × 10⁻⁴ T, then the e.m.f. developed between the two ends of the conductor is

A coil is suspended in a uniform magnetic field, with the plane of the coil parallel to the magnetic lines of force. When a current is passed through the coil it starts oscillating; it is very difficult to stop. But if an aluminium plate is placed near to the coil, is stops. This is due to

Two coaxial solenoids are made by winding thin insulted wire over a pipe of cross-sectional area A = 10 cm² and length = 20 cm. If one of the solenoids has 300 turns and the other 400 turns, their mutual inductance is
(μ₀ = 4π × 10^-7 T mA^-1)