$A$ varying current in a coil changes from $10 \, A$ to $0 \, A$ in $0.5 \, s$. If the average $EMF$ induced in the coil is $220 \, V$,the self-inductance of the coil is ... $H$.

If a coil is open,then its self-inductance $L$ and resistance $R$ become:

In the following circuit,the bulb will become suddenly bright if

What is the self-inductance of a coil in which an induced emf of $2 \,V$ is set up, when the current is changing at the rate of $4 \,A s^{-1}$?

The current flowing through an inductance coil of self-inductance $6 \text{ mH}$ at different time instants is as shown. The emf induced between $t=20 \text{ s}$ and $t=40 \text{ s}$ is nearly

An air-cored solenoid with length $30 \; cm$,area of cross-section $25 \; cm^{2}$ and number of turns $500$,carries a current of $2.5 \; A$. The current is suddenly switched off in a brief time of $10^{-3} \; s$. How much is the average back $emf$ induced (in $V$) across the ends of the open switch in the circuit? Ignore the variation in magnetic field near the ends of the solenoid.