Which type of electricity changes direction periodically?

Alternating current (AC) is characterized by the periodic change in the direction of the flow of electric charge. In AC, the voltage rises and falls in a cyclical manner, which leads to the current reversing its flow at regular intervals. This is in contrast to direct current (DC), where the electric charge flows in a single direction continuously.

The periodicity in AC is typically measured in hertz (Hz), representing the number of cycles per second. This alternating nature makes AC suitable for powering homes and businesses, as it can be easily transformed to different voltage levels, helping to transmit electricity over long distances efficiently.

Understanding this feature of AC is essential in various applications, from household electrical systems to large scale power grids, as it directly affects how electrical devices are powered and how energy is distributed.