What is the definition of alternating current (AC)?

The definition of alternating current (AC) is indeed that it reverses direction periodically. This means that in an AC circuit, the flow of electric charge changes direction at regular intervals. This is in contrast to direct current (DC), where the current flows in a single direction consistently.

AC is commonly used in household electrical systems and for powering large electrical devices due to its ability to be easily transformed to different voltages, making it efficient for long-distance transmission. The characteristics of AC allow it to fluctuate in waveform, often represented as a sine wave, which indicates the periodic nature of its direction change.

This understanding of AC is critical for applications in various electrical systems, as it plays a significant role in how electricity is generated and distributed, particularly in residential and commercial settings.