Question

A series LCR circuit with $R=20\Omega$, $L=1.5$H and $C=35\mu F$ is connected to a variable-frequency $200$V ac supply. When the frequency of the supply equals the natural frequency of the circuit, what is the average power transferred to the circuit in one complete cycle?

Answer 1

Impendance is equal to resistance,

$z=R,\varphi =0^o$

$I_V=\frac{E_V}{Z}=\frac{200}{20}=10A$

$P=E_V{I}_{V}cos{0}^o=200\times 10\times 1=2000watt$