explain the phasor diagrams for alternating emf and alternating current

Dear Student,

A phasor diagram represents the phase relationship between the alternating current and alternating e.m.f. The peak values are represented by the arrows called phasors which can be rotated in the anticlockwise direction.

A phasor diagram is drawn to show the phasor relationship between voltage and current in an AC circuit.

The phasor diagram is drawn corresponding to time zero along the horizontal axis. The lengths of the phasors are proportional to the values of the voltage and the current at the instant in time. From the diagram we can easily find out whether the current and voltage are in phase or one of them is lagging behind.