Question

In an A.C circuit current is 2A and voltage is 220V and the power is 44 W power factor is _ _ _ _ _
A. 0.10
B. 1.80
C. 0.09
D. 0.18

Answer 1

This is a direct question. We will use the formula that relates the power, current, voltage, and power factor. We will substitute the given values of the power, current, and voltage values in the equation to find the value of the required value of the power factor.
Formula used:
$P=VI\cos \phi$

Complete step-by-step solution
The formula that relates the power, current, voltage, and the power factor is given as follows.
$P=VI\cos \phi$
Where P is the power, V is the voltage, I is the current, and$\cos \phi$is the power factor.
From the data, we have the data as follows.
The power value of an A.C circuit is, P = 44 W
The current value of an A.C circuit is, I = 2 A
The voltage value of an A.C circuit is, V = 220 V
Substitute the given values in the above equation mentioned.

& 44=220\times 2\times \cos \phi \\\ & \cos \phi =\dfrac{44}{220\times 2} \\\ \end{aligned}$$ Continue the further calculation to find the value of the power factor. $$\begin{aligned} & \cos \phi =\dfrac{44}{440} \\\ & \cos \phi =\dfrac{1}{10} \\\ \end{aligned}$$ Therefore, the value of the power factor is 0.1. The power factor is the ratio of the real power to the apparent power flowing in the circuit. This power factor represents energy efficiency. $$ \therefore $$ The value of the power factor is 0.1. **As the value of the power factor is 0.1, thus, option (A) is correct.** **Note:** In this question, the value of the power factor is asked by giving the values of the power, current and voltage. Even they may ask for the value of power or current or voltage by giving the other values. The units of the parameters should be taken care of.