In LCR series circuit, R =18 and impedance 33 . An r.m.s. voltage of 220 V is applied across the circuit. The true power consumed in a.c. circuit is

Step-by-step solution

Given: Resistance R = 18 , impedance Z = 33 , and RMS voltage V_ rms = 220 . True power in an AC circuit is given by P = I_ rms ^2 R , where I_ rms = V_ rms Z . Substituting values yields: I_ rms = 220 33 = 20 3 Then, P = ( 20 3 )^2 18 = 400 9 18 = 400 2 = 800 W Alternatively, using power factor = R Z in P = V_ rms I_ rms leads to the equivalent formula: P = V_ rms ^2 R Z^2 = 220^2 18 33^2 = 400 18 9 = 800 W Thus, the true power consumed is 800 W , corresponding to option C.