A conducting circular loop is placed in a uniform magnetic field of inducting B tesla with its plane normal to the field. Now, radius of the loop starts shrinking at the rate (dr/dt). Then the induced e.m.f. at the instant when the radius is r is :

A varying current in a coil changes from 10 amp to zero in 0.5 sec. If average EMF is induced in
the coil is 220 volts, the self inductance of coil is :

The figure shows four wire loops, with edge lengths of either L or 2L. All four loops will move
through a region of uniform magnetic field \[\overrightarrow{B}\] (directed out of the page) at the same constant velocity. Rank the four loops according to the maximum magnitude of the e.m.f induced as they move through the field, greatest first :-

How much length of a very thin wire is required to obtain a solenoid of length l0 and inductance L.

An equilaterial triangular loop having a resistance R and length of each side ‘l’ is placed in a magnetic field which is varying at dB/dt =1 T/s. The induced current in the loop will be :

Two coils carrying current in opposite direction placed co-axially as shown in figure. Now that brought closer to each other, than :

The network shown in the figure is part of a complete circuit. If at a certain instant, the current
I is 5A and it is decreasing at a rate of

\[10^{3} As^{-1} then V_{B}-A_{A} equals\]

For the circuit shown in figure R = 10Ω, L = 5H, E = 20 V, i = 2 A. This current is decreasing at
a rate of 1.0 A /s Find Vab at this instant.

Using Lenz’s Law, determine the direction of current flow in the loop for each of the two
situations shown below.

Select the correct alternative. A thin semicircular conducting ring of radius R is falling with its plane vertical in a horizontal magnetic induction \[\overrightarrow{B}\] . At the position MNQ the speed of the ring is v & the potential difference developed across the ring is :