Question

The power loss in an AC circuit is ${{E}_{rms}}{{I}_{rms}}$, when there in the circuit there is only
$\begin{align}
  & A. C \\
 & B. L \\
 & C. R \\
 & D. L,C,R \\
\end{align}$

Answer 1

Hint: Electrical power used up by a resistor in an AC circuit is very much different from the power consumed by the reactance since reactances do not dissipate energy. In a direct current circuit, the power consumed is given as the product of the DC voltage times the DC current, which is given in watts.

Complete step by step answer:
The ratio of the power absorbed by the input circuit of a transducer to the power delivered to a specified load; usually expressed in decibels. The power factor of an AC electrical power system is described as the ratio of the real power flowing into the load to the apparent power in the circuit. It is given as a dimensionless quantity and in the closed interval of -1 to 1. Inductors as well as capacitors bring a phase difference in between the voltage and the current in the circuit, hence varying the power factor. That is when there is only a resistance is present the power factor becomes one.
We also know that, the power loss in an AC circuit is given as,
$PL={{E}_{rms}}{{I}_{rms}}\times$ power factor
So here the power factor should be one for the required answer.

So, the correct answer is “Option C”.

Note: The ideal power factor is given as unity, or one. The value which is less than one means that extra power is needed to achieve the actual task at hand. All current flow will result in losses both in the supply and distribution system. A load with a power factor of one will cause the most efficient loading of the supply.