Electromagnetic Induction and Alternating Currents: JEE Main 2021 Physics question

An inductor of 10 mH is connected to a 20V 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 ${x \over {100}}$ mA. Then x is equal to ___________. (Take e^$-$1 = 0.37)