Question

A 3.1-µF capacitor has a voltage of 31 V between its plates. What must be the current in a 5.6-mH inductor so that the energy stored in the inductor equals the energy stored in the capacitor?

Answer 1

(1/2) L i^2 = (1/2) C V^2

i^2 = (C/L) V^2

i^2 = (3.1*10^-6 / 5.6*10^-3) (961)

i^2 = 532 * 10^-3 = 53.2 * 10^-4

i = 7.3 * 10^-2 = .073 amps