$A$ coil having effective area $A$ is held with its plane normal to a magnetic field of induction $B$. The magnetic induction is quickly reduced by $25 \%$ of its initial value in $2 \ s$. The e.m.f. induced across the coil will be:

$A$ cylindrical bar magnet is kept along the axis of a circular coil. If the magnet is rotated about its axis,then

Discuss Faraday's experiment which shows that relative motion is not an absolute requirement for electromagnetic induction.

$A$ coil of $n$ turns and area $A$ is suddenly removed from a magnetic field,and a charge $q$ flows through the coil. If the resistance of the coil is $R$,then the magnetic flux density is (in $Wb/m^2$):

$A$ 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

To induce an $e.m.f.$ in a coil, the linking magnetic flux