An inductor of \( 10 \, \text{mH} \) is connected to a \( 20 \, \text{V} \) battery through a resistor of \( 10 \, \text{k}\Omega \) 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 \( 1 \, \mu \text{s} \) is \( \dfrac{x}{100} \, \text{mA} \). Then \( x \) is equal to __________________ .
(Take \( e^{-1} = 0.37 \) )
