In an electrical circuit,$R$,$L$,$C$,and an $a.c.$ voltage source are all connected in series. When $L$ is removed from the circuit,the phase difference between the voltage and the current in the circuit is $\frac{\pi}{3}$. If instead $C$ is removed from the circuit,the phase difference is again $\frac{\pi}{3}$. The power factor of the circuit is $(\tan \frac{\pi}{3} = \sqrt{3})$.

• A
  $\frac{\sqrt{3}}{2}$
• B
  $\frac{1}{2}$
• C
  $\frac{1}{\sqrt{2}}$
• D
  $1$