In the circuits shown what is the phase relationship Iphase

In the circuits shown, what is the phase relationship Iphase quantities shown in - (f) below. State which one I voltage or current) leads.

Solution

Rules to the phase difference between Voltage and current phasors:

1. If circuit has resistor, the voltage and current phasors are in phase, so phase difference is zero degrees.

2. If circuit has inductor, the current phasor is lagging to voltage phasor, so the phase difference is negative and non-zero.

3. If circuit has capacitor, the current phasor is leading to voltage phasor, so phase diffrence is positive and non-zero.

The above two circuits(series and parallel networks) have only resistor elements.so in all cases (a)- (f) the phase difference is zero.