Switch S is closed for long time in the figure shown. Find the current i as soon as the switch is opened.
3. The attempt at a solution
At t=∞ inductor behaves as closed circuit. So, I can simply replace it with a wire and calculate the current which comes out to be 9A. But I can’t understand what will happen when the switch is opened. Will the current die out instantly? Will it be the same as before?