Consider an RL circuit (Fig. P21.38) with V = 9.0 V, L = 5.5 mH, and R 1500. After the switch has been left open

Consider an RL circuit (Fig. P21.38) with V = 9.0 V, L = 5.5 mH, and R 1500Ω. After the switch has been left open for a long time, the switch is closed at t = 0.
(a) What is the current the instant after the switch is closed?
(b) What is the current a very long time after the switch is closed?
(c) How long does it take the current in the circuit to reach 50% of its final (long time) value?

Figure 21.38

 

ll