Which of the following best describes how alternating current behaves?

• A. It flows steadily in one direction.
• B. It regularly reverses its direction.
• C. It computes electrical resistance.
• D. It measures electric charge over time.

Answer: (B)

Alternating current (AC) is characterized by its ability to regularly reverse its direction. This means that the flow of electrons in an AC circuit changes polarity; the current flows in one direction for a period and then in the opposite direction after a set time interval. This behavior allows AC to effectively transfer energy over long distances, which is why it is commonly used for power distribution in residential and commercial applications.

In contrast, a steady flow in one direction would describe direct current (DC), which does not reverse direction and maintains a constant voltage over time. Concepts such as calculating electrical resistance or measuring electric charge pertain to other functionalities in electrical theory but do not define the fundamental behavior of alternating current. Thus, the alternating nature of AC makes it distinct and particularly useful for varied applications in electrical systems.