Question

Current in a circuit is wattless if

• A. inductance in the circuit is zero
• B. resistance in the circuit is zero
• C. current is alternating
• D. resistance and inductance both are zero

Answer 1

Answer: (B)

resistance in the circuit is zero

Answer 2

If $R = 0 \, \Rightarrow \, \cos \, \phi = 0 \, \Rightarrow \, \phi = 90^{\circ}$ so P = 0, in this case, powerloss is zero & currentflowing in the circuitis called wattless current.

The current in the circuit is wattless, Hence, power = i2R, if P = 0, then R = 0.