Consider the circuit shown in the figure below, where L = 4.55 mH and R2 = 475 Ω. The switch S can be positioned at either a or b. (a) When the switch is at position a, the time constant is 14.7 μs. What is R1 (in kΩ)? kΩ (b) What is the current in the inductor at the instant the switch is thrown to position b? mA