In the given figure,the magnet is moved towards the coil with speed $v$ and the induced $emf$ is $e$. If the magnet and the coil recede away from one another,each moving with speed $v$,the induced $emf$ in the coil will be

In a coil of area $10 \; cm^2$ and $10$ turns, a magnetic field is directed perpendicular to the plane and is changing at the rate of $10^8 \; G/s$. The resistance of the coil is $20 \; \Omega$. The current in the coil will be ......... $A$.

$A$ circular coil of radius $10 \; cm$, $500$ turns, and resistance $2 \; \Omega$ is placed with its plane perpendicular to the horizontal component of the earth's magnetic field. It is rotated about its vertical diameter through $180^{\circ}$ in $0.25 \; s$. The induced e.m.f. in the coil is (Take $B_H = 3.0 \times 10^{-5} \; T$).

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.

$A$ closed planar wire loop of area $A$ and arbitrary shape is placed in a uniform magnetic field of magnitude $B$,with its plane perpendicular to the magnetic field. The resistance of the wire loop is $R$. The loop is now turned upside down by $180^o$ so that its plane again becomes perpendicular to the magnetic field. The total charge that must have flowed through the wire ring in the process is

Magnetic flux $\phi$ (in weber) linked with a closed circuit of resistance $10\, \Omega$ varies with time $t$ (in seconds) as $\phi = 5t^2 - 4t + 1$. The induced electromotive force in the circuit at $t = 0.2\, s$ is ......... $V$.