Q.
An inductor of $10\, mH$ is connected to a $20\, V$ battery through a resistor of $10\, k\, \Omega$ and a switch.
After a long time, when maximum current is set up in the circuit, the current is switched off. The current in the circuit after $1\, \mu s$ is $\frac{x}{100} m A$. Then $x$ is equal to_______.
(Take $e^{-1}=0.37$ )
Solution: