How does direct current (DC) differ from alternating current (AC)?

Direct current (DC) is characterized by the fact that it flows in a single direction, maintaining a constant polarity. This means that the electrical charge moves steadily from the negative terminal to the positive terminal, providing a continuous flow of electricity. In contrast, alternating current (AC) reverses its direction periodically. This ability to change direction frequently allows AC to be more suitable for long-distance power transmission because it can easily be transformed to higher or lower voltages.

Understanding this distinction is crucial for numerous applications in electrical systems. For example, many battery-operated devices use DC because it is easy to store and is stable, while power plants typically use AC because it can be transmitted efficiently over long distances and is more convenient for use in household circuits.

The assertion that AC flows in one direction while DC periodically reverses direction is incorrect, which highlights the importance of recognizing these fundamental differences in electrical current types. AC does not generate less heat compared to DC under the same conditions; rather, the heat generation depends on several factors, including resistance in the circuit. Therefore, the specific characteristics of DC and AC primarily revolve around their directionality and changes over time, clarifying why the chosen answer stands correct.