Question

A resistor and an inductor are connected to an ac supply of 120 V and 50 Hz, the current in the circuit is 3 A. If the power consumed in the circuit is 108 W, then the resistance in the circuit is
A. (A) `12 Omega`
B. (B) `40 Omega`
C. (C) `sqrt((52 xx 28))Omega`
D. (D) `360 Omega`

Answer 1

Correct Answer - A
In an ac circuit, a pure inductor does not consume any power. Therefore, power is consumed by the resistor only.
`:. P=I_(V)^(2) R` ltbRgt or `108 =(3)^(2) R or R = 12 Omega`.