Question

The power factor of the circuit as shown in figure is

• A. $0.2$
• B. $0.4$
• C. $0.8$
• D. $0.6$

Answer 1

The correct option is C $0.8$


Given,
$V=220VR=40+40=80\Omega X_L=100\Omega X_C=40\Omega$


Impedence ,$Z=\sqrt{R^2+(X_L-X_C{)}^2}=\sqrt{{80}^2+(100-40{)}^2}=100\Omega$

Power factor, $cos\varphi =\frac{R}{Z}$

$\therefore cos\varphi =\frac{80}{100}=0.8$