Question

In an L-C-R circuit, if impedance is $\sqrt{3}$ times of resistance and capacitive reactance is zero. Find the phase difference.

• A. zero
• B. $30^{\circ }$
• C. $60^{\circ }$
• D. Data is incomplete

Answer 1

Answer: (C)

The phasor diagram of L-C-R circuit shows that phase angle $\varphi$ is given by

$\tan \varphi =\frac{V_L-V_C}{V_R}=\frac{X_L-X_C}{R}$
Given, $X_C=0,X_L=\sqrt{3}R$
$\therefore \varphi ={\tan }^{-1}\left(\frac{\sqrt{3}R}{R}\right)$
$\Rightarrow \varphi ={\tan }^{-1}(\sqrt{3})=60^{\circ }$