Question

What is the average power over one complete cycle for a capacitor connected to an AC source?

Options

• \[P_{\mathrm{avg}}=v_mi_m\]

• \[P_{\mathrm{avg}}=0\]

• \[P_{\mathrm{avg}}=\frac{v_mi_m}{2}\]

• \[P_{\mathrm{avg}}=\omega Cv_m\]

Answer 1

Instantaneous power is proportional to \[\sin 2\omega t\], whose average over a full cycle is zero. Thus, the capacitor consumes no net energy over one complete cycle.