A 40 µF capacitor is connected across a 220 V, 50 Hz supply. Calculate (a) the reactance of the capacitor, and (b) the current flowing through the circuit.

Solution:

1. The reactance, X_c = 1/2πfC = 1/ (2 x 3.14 x 50 x 40x10^-6) = 79.6 Ω.
2. The current is V_RMS/X_c = 220/79.6 = 2.76 A.