The switch in the circuit of Fig. 8.55 has been closed a ridiculously long time before sud...

The switch in the circuit of Fig. 8.55 has been closed a ridiculously long time before suddenly being thrown open at t = 0. (a) Obtain expressions for iL and υ in the circuit of Fig. 8.55 which are valid for allt ≥ 0. (b) Calculate iL.(t) and υ(t) at the instant just prior to the switch opening, at the instant just after the switch opening, and at t = 470 μs.