Question-23 In LCR series circuit, R=18\ \Omega and impedance 33\ \Omega. An r.m.s. voltage of 220\ V is applied across the circuit. The true power consumed in a.c. circuit is
(A) 400\ W
(B) 600\ W
(C) 800\ W
(D) 900\ W
Answer : (C)
Explanation:
I = \frac{V}{Z} = \frac{220}{33} = \frac{20}{3} A
P = I^2 R = \left(\frac{20}{3}\right)^2 \times 18 = 800 W