What describes electric current that periodically reverses direction?

The type of electric current that periodically reverses direction is known as alternating current (AC). This means that the flow of electric charge changes its direction periodically, which can be characterized by sinusoidal waveforms in its graphical representation. AC is commonly used in household electricity and electrical power systems because it allows for efficient transmission over long distances and can easily be transformed to different voltage levels.

In contrast, direct current (DC) flows in only one direction, providing a constant voltage or current. Pulsating current typically refers to a form of direct current that varies in amplitude but does not change direction, and static current does not exist in the context of electric current as it implies a lack of movement of charge. Thus, alternating current stands out as the correct description for current that reverses direction periodically.