Question

Current of $\frac{50}{\pi }Hz$ frequency is passing through an A.C circuit having series combination of resistance $R=100\Omega$ and inductor $L=1H$, then phase difference between voltage and current is ______.

• A. ${60}^o$
• B. ${30}^o$
• C. ${45}^o$
• D. ${90}^o$

Answer 1

The correct option is C ${45}^o$

$\omega =2\pi f=2\pi \times \frac{50}{\pi }=100\therefore X_L=\omega L=100\Omega Z=\sqrt{R^2+X_L^2}=\sqrt{{\left(100\right)}^2+{\left(100\right)}^2}=100\sqrt{2}\cos \varphi =\frac{R}{Z}=\frac{1}{\sqrt{2}}\therefore \varphi =45°$