Question

What is wattless current?

Answer 1

Wattles Current

1. When simply an inductor or capacitor is connected to a circuit, the power consumption is zero and the current is known as wattless current, as it consumes no energy in the circuit.
2. In other words, when the average power consumed in an AC circuit equals zero, the current is referred to be Wattless current. This type of current is also known as Idle Current.
3. The wattles current is calculated using the following formula:

$P=VI\cos \left(\theta \right)$

where, P -denotes the power in Watts.

V - the voltage in Volts

I - the current in Amperes

4. The phase difference between voltage and current is $\frac{\mathrm{\pi }}{2}$ when only an inductor or capacitor is present in the circuit.
As a result, the power consumption can be calculated using the formula above.

$P=VI\cos \left(\frac{\mathrm{\pi }}{2}\right)$

We know that $\cos \left(\frac{\mathrm{\pi }}{2}\right)=0$.
As a result, $P=0watt$

We can readily see that when the phase difference is $\frac{\mathrm{\pi }}{2}$ there is no power consumption, hence this is referred to as wattless current.