Case (ii) Purely inductive or capacitive circuit: If the circuit contains
only an inductor or capacitor, we know that the phase difference between
voltage and current is p/2 Therefore, cos f = 0, and no power is dissipated
even though a current is flowing in the circuit This current is sometimes
referred to as wattless current Case (iii) LCR series circuit: In an LCR series circuit, power dissipated is
given by Eq