Problem 4.118

A coil with active resistance $R$ and inductance $L$ was connected at the moment $t=0$ to a source of voltage $V=V_{m} \cos \omega t$ . Find the current in the coil as a function of time $t$ .

Reveal Answer

I=\frac{V_{m}}{\sqrt{R^{2}+\omega^{2} L^{2}}}\left[\cos (\omega t-\varphi)-\cos \varphi \cdot e^{-t R / L}\right], \tan \varphi=\omega L / R

Electric Oscillations