In alternating current, where does the voltage begin during each sine wave cycle?

The correct answer for where the voltage begins during each sine wave cycle in alternating current is at zero level. In a typical sine wave, the cycle begins at zero volts, progresses to a positive peak (maximum level), returns to zero, goes to a negative peak (minimum level), and returns again to zero. This represents one complete cycle of the AC waveform.

Understanding that the sine wave is a smooth repetitive oscillation helps clarify this. The sine wave starts at zero, moves upward to reach maximum voltage, decreases back to zero, goes negative to reach the minimum voltage, and finally returns to zero. The concept of cycles in alternating current is fundamental to its operation, where voltage and current alternate their direction and magnitude in a sinusoidal manner.

Thus, to summarize, the cycle commences at the zero voltage level, which is a key characteristic of how alternating current behaves over its waveforms.