When an alternating voltage of $220 \mathrm{V}$ is applied across a device $P$, a current of $0.25 \mathrm{A}$ Flows through the circuit, and it leads the applied voltage by an angle $\frac{\mathrm{\pi }}{2} \mathrm{radian}$ . When the same voltage source is connected across another device $Q$, the same current is observed in the circuit but in phase with the applied voltage. What is the current when the same source is connected across a series combination of $P$ and $Q$.