$A$ coil having effective area $A$ is held with its plane normal to a magnetic field of induction $B$. The magnetic induction is quickly reduced to $25 \%$ of its initial value in $1 \ s$. The e.m.f. induced in the coil (in volt) will be

$A$ hundred turns of insulated copper wire are wrapped around an iron cylinder of area $1 \times 10^{-3} \ m^2$ and are connected to a resistor. The total resistance in the circuit is $10 \ \Omega$. If the longitudinal magnetic induction in the iron changes from $1 \ Wb/m^2$ in one direction to $1 \ Wb/m^2$ in the opposite direction,how much charge flows through the circuit?

The graph shows the magnitude $B(t)$ of a uniform magnetic field that exists throughout a conducting loop,perpendicular to the plane of the loop. Rank the five regions of the graph according to the magnitude of the emf induced in the loop,greatest first.

$A$ conducting circular coil is placed in a uniform magnetic field with the magnetic field initially directed perpendicular to the plane of the coil. In step $A$,the coil is rotated from its initial position by $60^{\circ}$ about its diameter in time $t$. In step $B$,the coil is further rotated about the same axis in the same sense by another $120^{\circ}$ in time $2t$. The ratio of the emf induced in the coil in step $A$ to that in step $B$ is:

$A$ circular coil is placed near a current-carrying conductor, both lying on the plane of the paper. The current is flowing through the conductor in such a way that the induced current in the loop is clockwise, as shown in the figure. The current in the wire is,

If a coil of metal wire is kept stationary in a non-uniform magnetic field, then