Chapter 2, Problem 2.16P

A single-phase, $120-\text{V}\left(\text{rms}\right),60-\text{Hz}$ source supplies power to a series $\text{R-L}$ circuit consisting of $\text{R}\text{=}\text{10}\Omega$ and $\text{L}\text{=}\text{40}\text{mH}$. (a) Determine the power factor of the circuit and state whether it is lagging or leading. (b) Determine the real and reactive power absorbed by the load. (c) Calculate the peak magnetic energy $W_{\mathrm{int}}$ stored in the inductor by using the expression $W_{\mathrm{int}}=\text{L}{\left({\text{I}}_{\text{rms}}\right)}^2$ and check whether the reactive power $\text{Q}=\omega W_{\mathrm{int}}$ is satisfied. (Note: The instantaneous magnetic energy storage fluctuates between zero and the peak energy. This energy must be sent twice each cycle to the load from the source by means of reactive power flows.)