# 13.5: Resistance and Capacitance in Series

Likewise the impedance of a resistance and a capacitance in series is

\[\label{13.5.1}Z=R-j/(C\omega).\]

The voltage and current are related, as usual, by

\[V = IZ.\]

Equation \ref{13.5.1} shows that the voltage lags behind the current by

\[\tan^{-1} \dfrac{1}{RC\omega}.\]

and that

\[\dfrac{\hat{V}}{\hat{I}}=\sqrt{R^2+1/(C\omega)^2}.\]