How many times does the voltage drop to zero in a 60 hertz single-phase AC circuit each second?

In a 60 hertz single-phase alternating current (AC) circuit, the frequency of 60 hertz indicates that the current completes 60 cycles per second. Within each cycle, the voltage goes from zero to its maximum positive value, drops back through zero to its maximum negative value, and then returns to zero again.

This means that in one complete cycle, the voltage crosses zero two times: once when transitioning from positive to negative and once again when returning to positive after reaching the negative peak. Therefore, in one second, since the AC circuit oscillates 60 times, the total number of times the voltage drops to zero is doubled, resulting in 120 instances where the voltage is zero in a one-second timeframe.

This understanding of AC waveforms and their behavior is critical for electrical professionals, as it influences the design and functioning of electrical systems.