Resistance and Inductance in AC Series

The following figure shows an inductor in series with a resistor in an AC circuit. An inductor is a length of wire wound into a coil.

FIGURE

        The following is the waveform diagram and the phasor diagram that shows that voltage and current are out of phase by an angle less than 90^o_.

FIGURE

FIGURE

        In the phasor diagram, the voltage across the resistor (V_R) is in phase with the current and the voltage across the inductor (V_L) leads the current by 90^o.

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