Question

In ac circuit, resistance 5 ohm is connected with a capacitor having capacitive reactance 12 ohm. Supply of 260 V is connected to the circuit. Calculate the voltage across a capacitor.

(a) 300 V

(b) 200 V

(c) 240 V

(d) 100 V

Answer 1

Correct choice is (c) 240 V

Easiest explanation: Z^2=R^2+XC^2 Substituting the values we get

Z^2 = 5^2 + 12^2

Z^2 = 169

Z=13 Ω.

I = V/Z = 260/13=20 A.

VC=iXC=20*12=240 V.