$A$ coil having an area $A_0$ is placed in a magnetic field which changes from $B_0$ to $4B_0$ in a time interval $t$. The $e.m.f.$ induced in the coil will be

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

The magnetic flux linked with a coil (in $Wb$) is given by the equation $\phi = 5t^2 + 3t + 16$. The magnitude of induced emf in the coil at the fourth second will be (in $V$):

$A$ coil having an area $2\,m^2$ is placed in a magnetic field which changes from $1\,Wb/m^2$ to $4\,Wb/m^2$ in an interval of $2$ seconds. The $e.m.f.$ induced in the coil will be......$V$.

Discuss Faraday's experiment of bar magnet and coil for generation of electric current in coil.

$A$ long solenoid having $100$ turns per $cm$ carries a current of $\frac{4}{\pi} \,A$. At the centre of it is placed a coil of $200$ turns of cross-sectional area $25 \,cm^2$ having its axis parallel to the field produced by the solenoid. When the direction of the current in the solenoid is reversed within $0.04 \,s$, the induced emf in the coil is (in $\,V$)