Electromagnetic Induction

According to Lenz's law of electromagnetic induction

The horizontal component of earth's magnetic field at a place is 4 * 10^–4 T and dip is 45°. A metal rod of length 20 cm is placed in north south direction and is moved at constant speed of 5 cm/s towards East. What is e.m.f. induced in the rod?

Three long wires, carrying current 10 A, 20 A and 30 A are placed parallel to each other as shown. Point P and Q are in midway of wires. What is ratio of magnetic field at P to the Q?

A particle moves along x axis from x = 1 m to x = 3 m under the effect of the force F = 3x² – 2x + 5 N. Work done in process is

In an electric transformer, 220 V is applied on primary coil having number of turn 100. Find output current through 3 W resistance if number of secondary turn is 10.

The magnetic flux through a loop varies with time as f = 5t² − 3t + 5. If the resistance of loop is 8 W, find the current through it at t = 2 s

The core of a transformer is laminated to reduce energy losses due to

The current in a coil changes from 8 A to zero in 0.2 s. If self-inductance is 4 H then average induced emf is:

Two co-planar circular loops are placed concentrically as shown in figure. The radius of the outer and inner loops are R and r respectively R >> r. The mutual inductance between them will be

 

A square loop of side l is placed at a separation a with a very long wire AB, in same plane. If the current through BA is increasing in the direction shown, the induced current produced in the loop is