$(i)$ What is the angle between the phasor of $V_R$ and $I$?
$(ii)$ The voltage phasor $V_C$ is ...... of the current phasor $I$. (Fill in the blank)

(N/A) $(i)$ In a purely resistive circuit,the voltage $V_R$ and the current $I$ are in the same phase. Therefore,the phase angle between the phasor of $V_R$ and $I$ is $0^{\circ}$.
$(ii)$ In a purely capacitive circuit,the voltage $V_C$ lags behind the current $I$ by a phase angle of $90^{\circ}$ or $\pi/2$ radians. Thus,the voltage phasor $V_C$ is $90^{\circ}$ behind the current phasor $I$.