What is the primary distinction between alternating current (AC) and direct current (DC)?

The primary distinction between alternating current (AC) and direct current (DC) lies in the manner in which the electric charge flows. With AC, the electric current periodically reverses its direction, frequently changing its voltage level over time. This characteristic of AC allows for the efficient transmission of power over long distances, as the alternating fluctuations can be easily transformed to higher voltages, reducing energy loss during transmission.

On the other hand, DC maintains a constant voltage and flows only in one direction. This stable flow is beneficial for battery-operated devices and electronics but is not typically used for long-distance power transmission due to higher resistive losses.

Understanding these fundamental differences is essential in electrical engineering and applications, as it impacts the selection of the type of current used in various systems and devices.