As a result of a change in the magnetic flux linked to the closed loop as shown in the figure,an $e.m.f.$ $V$ volt is induced in the loop. The work done (in joule) in taking a charge $Q$ coulomb once along the loop is

$A$ and $B$ are two metallic rings placed at opposite sides of an infinitely long straight conducting wire as shown. If current in the wire is slowly decreased,the direction of induced current will be

$A$ coil having $n$ turns and resistance $R \ \Omega$ is connected with a galvanometer of resistance $4 R \ \Omega$. This combination is moved in time $t$ seconds from a magnetic flux $\phi_1$ Weber to $\phi_2$ Weber. The induced current in the circuit is

As shown in the figure, two identical conducting rings of radius $r$ are placed in a magnetic field. In figure $(a)$, the magnetic field is increasing at the rate of $0.3 \text{ T/s}$, and in figure $(b)$, the magnetic field is decreasing at the rate of $0.2 \text{ T/s}$. The direction of the current in ring $(a)$ and ring $(b)$, when observed from the top, is . . . . . .

Two circular coils $A$ and $B$ are facing each other as shown in the figure. The current $i$ through coil $A$ can be altered.

The following figure shows planar loops of different shapes moving into or out of a region of a magnetic field which is directed normal to the plane of the loop,away from the reader. Determine the direction of the induced current in each loop using Lenz's law.