Question

The power factor of a good choke coil is:
A. Nearly zero
B. Exactly zero
C. Nearly one
D. Exactly one

Answer 1

In this question we will understand the power factor of the choke coil. In an electrical circuit, a choke coil is an inductor that is used to prevent high frequencies of AC. Resistors are used to precisely lower the current in a circuit. Current passing through the resistor is limited due to the presence of voltage across it. And it converts electrical energy into heat. The resistance of a choke coil, on the other hand, does not limit the current. It works based on induction methods.

Complete step by step answer:
Because the phase difference between voltage and current is about ${90^ \circ }$ , the power factor of a good choke coil is virtually zero i.e, $\cos \phi = 0$. Also, choke coils are used in electrical circuits to limit current. In AC circuits, we use it to replace resistance. A resistor will heat up when current passes through it.

As a result, when resistance is used as a current control mechanism, it wastes a significant amount of electrical energy in the form of heat, resulting in high power loss and lower current.Choke, on the other hand, works on the idea of inductance. As a result, the choke coil's power factor is extremely low. When compared to resistance, it absorbs a lot less power. Only hysteresis in the iron core causes energy loss, which is negligible compared to resistance.

A choke coil is a type of inductor that can be used in a circuit to block higher-frequency signals while allowing lower-frequency direct current (DC) and alternating current (AC) to flow. The quantity of AC that can pass through the circuit is limited by its reactance. Due to self-induction, the eddy currents created in a choke coil help to reduce the current in the circuit. Choke is a device that is only used in AC circuits. It cannot be used in DC circuits since its inductive reactance is 0 for DC current.

Therefore, the correct answer is option A.

Note: ${\text{Power factor = }}\dfrac{{{\text{True power}}}}{{{\text{Apparent power}}}}$
In which power factor is $\cos \theta$. Because actual power equals zero, the power factor for a completely inductive circuit is 0. Because the next side is 0 in length, the power triangle appears as a vertical line. The same might be argued for a circuit that is entirely capacitive. If the circuit contains no resistive components, the actual power must be 0, rendering any power in the circuit merely reactive.