Resistance and Capacitance in AC Series

The following figure shows a resistor and a capacitor in an AC circuit.

FIGURE

        The following is the waveform diagram and the phasor diagram that shows that voltage and current are out of phase by less than 90^o with current leading the voltage.

FIGURE

FIGURE

        In the phasor diagram, the voltage across the resistor (V_R) is in phase with the current and the voltage across the capacitor (V_C) lags the current by 90^o.

        In this case, the impedance is calculated using the following formulae.