COMEDK20269 May 2026Morning ShiftPhysicsAlternating CurrentActual
If wattless current flows in an AC circuit, then the circuit is:
Options
- ALR circuit
- BPurely capacitive circuit
- CPurely resistive circuit
- DLCR circuit
Correct answer
B. Purely capacitive circuit
Step-by-step solution
The average power dissipated in an AC circuit is given by P = V_ rms I_ rms , where is the phase difference between the voltage and the current. For wattless current, the average power dissipated must be zero, which means P = 0 . This implies = 0 , so the phase difference = 2 or - 2 . A phase difference of 2 occurs only in purely inductive or purely capacitive circuits. In a purely capacitive circuit, the current leads the voltage by exactly 2 , making the power factor zero. Therefore, wattless current flows in a p