Alternating Current

The resistor '$R$' inductance '$L$' and capacitance '$C$' are connected in series with an a.c. source. When 'L' is removed from the circuit, the phase difference between voltage and current in the circuit is $\dfrac{\pi}{3}$. If instead, C is removed from the circuit, the phase difference is again $\dfrac{\pi}{3}$. The power factor of the circuit is