In the circuit, switch S is opened at t=0 after having been closed for a long time.

a) How much energy is stored in the inductor at t=0?

b) What is the instantaneous rate of change of the inductor’s energy at t=0?

c) What is the average rate of change of the inductor’s energy between t=0.0 and t=1.0 s?

d) How long does it take for the current in the inductor to reach 0.0010 times its initial value?