An aluminium ring $B$ faces an electromagnet $A$. The current $I$ through $A$ can be altered.

$A$ long solenoid with $15$ turns per $cm$ has a small loop of area $2.0 \; cm^{2}$ placed inside the solenoid normal to its axis. If the current carried by the solenoid changes steadily from $2.0 \; A$ to $4.0 \; A$ in $0.1 \; s$, what is the induced $emf$ in the loop while the current is changing?

$A$ coil of surface area $200 \ cm^2$ having $25$ turns is held perpendicular to the magnetic field of intensity $0.02 \ Wb/m^2$. The resistance of the coil is $1 \ \Omega$. If it is removed from the magnetic field in $1 \ s$,the induced charge in the coil is . . . . . . $C$.

The direction of induced current is such that it opposes the very cause that has produced it. This is the law of

The north pole of a magnet is falling towards a metallic ring as shown in the figure. If looked at from above the ring,the direction of the induced current will be:

$A$ circular loop of wire of radius $14 \ cm$ is placed in a magnetic field directed perpendicular to the plane of the loop. If the field decreases at a steady rate of $0.05 \ Ts^{-1}$ in some interval,then the magnitude of the emf induced in the loop is (in $mV$)