What type of electric current periodically reverses its flow direction?

Alternating current (AC) is characterized by the periodic reversal of its flow direction. In AC, the electrons shift back and forth, changing their direction multiple times per second. This is in contrast to direct current (DC), where the flow of electric charge remains in a constant direction.

The periodic reversal inherent in AC allows for more efficient transmission of electricity over long distances compared to DC, which is why most power plants generate AC power for distribution. Applications of AC include household appliances, electric power grids, and many forms of electronic devices.

Knowing that AC varies with time—typically in a sinusoidal pattern—clarifies its distinct behavior compared to the other types of currents mentioned. Static current, which could refer to the stationary accumulation of charge, does not involve a flow. Pulsating current, while resembling AC, does not have a consistent frequency or waveform.

The dynamic nature of AC makes it a fundamental concept in understanding how electrical systems operate in everyday environments.