$A$ coil of area $100 \, cm^2$ has $500$ turns. $A$ magnetic field of $0.1 \, Wb/m^2$ is perpendicular to the coil. The field is reduced to zero in $0.1 \, s$. The induced $e.m.f.$ in the coil is $...... \, V$.

$A$ conducting loop of radius $10/\sqrt{\pi}$ $cm$ is placed perpendicular to a uniform magnetic field of $0.5$ $T$. The magnetic field is decreased to zero in $0.5$ $s$ at a steady rate. The induced emf in the circular loop at $0.25$ $s$ is (in $mV$)

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

The magnetic flux $\phi$ through a coil varies with time $t$ as shown in the diagram. Which graph best represents the variation of the induced electromotive force (e.m.f.) $E$ in the coil with time $t$?

$A$ coil of resistance $400\,\Omega$ is placed in a magnetic field. If the magnetic flux $\phi$ (in $Wb$) linked with the coil varies with time $t$ (in $s$) as $\phi = 50t^2 + 4$,the current in the coil at $t = 2\,s$ is $..........\,A$.

Assertion $(A)$: It is more difficult to push a magnet into a coil with a greater number of turns.
Reason $(R)$: The $emf$ induced in a coil opposes the motion of a magnet when it is moved towards the coil.