### JEE Mains Previous Years Questions with Solutions

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### AIEEE 2002

The power factor of $AC$ circuit having resistance $(R)$ and inductance $(L)$ connected in series and an angular velocity $\omega$ is
A
$R/\omega L$
B
$R/{\left( {{R^2} + {\omega ^2}{L^2}} \right)^{1/2}}$
C
$\omega L/R$
D
$R/{\left( {{R^2} - {\omega ^2}{L^2}} \right)^{1/2}}$

## Explanation

The impedance triangle for resistance $\left( R \right)$ and inductor $(L)$ connected in series is shown in the figure.

Power factor $\cos \phi = {R \over {\sqrt {{R^2} + {\omega ^2}{L^2}} }}$