An inductor of inductance `L` and ressistor of resistance `R` are joined in series and connected by a source of frequency `omega`. Power dissipated in the circuit is

Options

A. `((R^(2) + omega^(2) L^(2)))/(V)`
B. `(V^(2)R)/((R^(2) + omega^(2) L^(2)))`
C. `(V)/((R^(2) + omega^(2) L^(2)))`
D. `(sqrt(R^(2) + omega^(2) L^(2)))/(V^(2))`

Answer

B

Explanation

`P = Vl cos phi = V xx (V)/(sqrt(R^(2) + omega^(2) L^(2))) xx (R )/(sqrt(R^(2) + omega^(2) L^(2)))`
`P = (V^(2) R)/(R^(2) + omega^(2) L^(2))`