Question

The power factor of a good choke coil is

• A. Nearly zero
• B. Exactly zero
• C. Nearly one
• D. Exactly one

Answer 1

The correct option is A

Nearly zero

Step 1: Choke coil

1. A choke coil is an extremely low resistance inductance coil used to regulate the current in an alternate current circuit.
2. It can not be used in DC circuits.
3. And the cosine of the phase difference between voltage and current is known as the power factor. The phase difference between voltage and current in AC circuits should ideally be zero. As a result, the power factor is measured using the following formula:
4. $\text{Power factor=cos}\left(\varphi \right)$

Step 2: Formula used

It is understood that the power factor is defined as the cosine of the phase difference between voltage and current. So, it can be written that,

$\text{Power factor=cos}\left(\varphi \right)\text{where}\varphi =$phase difference between the voltage and the current phaser

Step 3: Compute power factor

We know that in the choke coil the phase difference$\left(\varphi \right)\approx {90}^{°}$. So,

$$\begin{gathered} \text{Power factor=cos}\left({90}^{°}\right) \\ \mathrm{Power}\mathrm{factor}=0 \end{gathered}$$

Power factor of good choke coil is nearly zero as phase difference $ɸ$ between voltage & current is almost $90°$. Thus, the power factor of a good choke coil is nearly zero.

Hence, option A is the correct answer.