Is it true that one cycle of alternating current starts at zero and returns to zero after moving in both directions?

The statement is true because one cycle of alternating current (AC) is defined as the complete movement of the current through its full range, starting from zero, increasing to a maximum positive value, decreasing back to zero, continuing to a maximum negative value, and then returning again to zero. This pattern demonstrates the bidirectional flow of current characteristic of AC.

Understanding this concept is crucial in electrical work, as it underpins how many electrical systems and devices operate. In a standard sine wave, which is a common waveform for AC, this cycle can be observed clearly, making it essential for apprentices to grasp the foundational behavior of AC currents. Knowing that a cycle includes both the positive and negative directions reinforces the understanding of power supply design and the functioning of various electrical equipment.

While specific cases or waveforms may present variations in the shape and characteristics of AC, the fundamental concept of a cycle starting and returning to zero remains consistent. Therefore, the straightforward affirmation regarding the nature of an AC cycle is correctly identified.