Question

The average power dissipated in a pure inductor is

• A. Zero
• B. $V{I}^2$
• C. $\frac{1}{2}VI$
• D. $\frac{V{I}^2}{4}$

Answer 1

The correct option is A

Zero

Step 1: Given Data

1. Pure Inductor
2. We need to find the average power

Step 2: Formula used

The power dissipated is given by, $P_{avg}=\frac{v_0{i}_0}{2}\cos \phi$

$v_0$ is the voltage, $i_0$ is the current and $\cos \phi$ is the power factor.

Step 2: Determine the average power dissipated

In a pure inductive circuit, the current is lagging behind the voltage by $90°$

Hence, the phase difference between the voltage and the current is $\phi =90°$

Therefore,

$$\begin{gathered} P_{avg}=\frac{v_0{i}_0}{2}\cos \phi \\ =\frac{v_0{i}_0}{2}\cos \left(90\right) \\ =0 \end{gathered}$$

Hence, option A is the correct option.