3 REPRESENTATION OF AC CURRENT AND VOLTAGE
BY ROTATING VECTORS — PHASORS
In the previous section, we learnt that the current through  a resistor is
in phase with the ac voltage But this is not so in the case  of an inductor,
a capacitor or a combination  of these circuit elements In order to show
phase relationship between voltage and current
in an ac circuit, we use the notion of phasors The analysis of an ac circuit is facilitated by the
use of a phasor diagram