To find the peak current, we first calculate the RMS current ($I$). According to the sources, the power consumed by a resistive element like a filament lamp is $P = V I$, where $V$ and $I$ are RMS values . Thus, $I = P / V = 100 \text{ W} / 200 \text{ V} = 0.5$ A. The relationship between the peak current ($i_m$) and the RMS current ($I$) is $i_m = I\sqrt{2}$ . Substituting the values, $i_m = 0.5 \times 1.414 = 0.707$ A.