An AC generator's coil is rotated in a uniform magnetic field at a frequency of $50 \mathrm{~Hz}$. I

Question

An AC generator's coil is rotated in a uniform magnetic field at a frequency of $50 \mathrm{~Hz}$. In one full second, how many times does the induced alternating current become zero?

Professor PC Thomas Classes · Answer

(b) : The induced alternating current follows a sinusoidal waveform ($I = I_0 \sin \omega t$). In a single complete cycle, a sine wave crosses the zero-axis exactly twice (at $\pi$ and $2\pi$ phase angles). Since the frequency is $50 \mathrm{~Hz}$, there are $50$ complete cycles in one second. Therefore, the current becomes zero $50 	imes 2 = 100$ times per second.