Question

Which of the following power factors results in less energy loss in an RL circuit?
(A) \[1\]
(B) \[0.2\]
(C) \[0.8\]
(D) \[0.4\]

Answer 1

Hint In the given question, we have been asked to make a comment on the energy loss in an RL circuit based on the power factor of the circuit; note that RL circuit is a resistor inductor circuit. Now we should know about the power factor and the energy loss and the relation between the two to make a statement. Let’s see the detailed solution.

Step by Step Solution
Power factor is a ratio that gives us real power as a multiple of the apparent. Power factor tells us how effectively and efficiently a circuit is using electricity.
Energy is lost in a circuit when the voltage and the current are not in the same phase and as the phase difference increases, the energy lost also increases. The power factor tells us how well a circuit is using electricity, and for using electricity efficiently, the voltage and the current should be in the same phase as well. Thus we can say that the deciding factor for both the power factor and the energy loss is the same. As the phase difference between the voltage and the current increases, the power factor increases and the energy loss increases.
Hence for lesser energy loss, the power factor should be less too. In the given question, the minimum power factor available is \[0.2\] , hence it should correspond to the minimum energy loss.

Hence option (B) is the correct answer.

Note
A power factor of one is said to be an ideal situation. Also, you should directly remember the result of this question: the energy loss in a given circuit is directly proportional to the power factor of the circuit. The circuit given to us in the question was an RL circuit, but this analysis applies to any circuit you may come across.