Capacitor in series with a parallel RL branch (${\omega }_{\ast }^{-2}=LC-L^2/R^2$)

For an ideal capacitor in series with a parallel resistor and inductor, $Z=1/(i\omega C)+(R\parallel i\omega L)$. A finite positive frequency with real input impedance exists precisely when $R^{2}C>L$. At that frequency ${\omega }_{\ast }=[LC-L^2/R^2{]}^{-1/2}$ and $Z_{\ast }=L/(RC)$. The resistor's voltage can exceed the source voltage because the reactive voltage drops cancel in the series sum; all average dissipation is still supplied by the source.