ARRL Technician Practice Exam 2026 - Free Technician License Practice Questions and Study Guide

Alternating current, commonly known as AC, is characterized by its ability to reverse direction periodically. This switching of direction occurs at a specified frequency, which is typically measured in hertz (Hz). In contrast to direct current (DC), where the flow of electric charge is in a constant direction, alternating current varies its direction and amplitude, making it more suitable for transmitting electricity over long distances.

This property of alternating current allows for the efficient operation of electrical appliances and motors that are designed to utilize this type of current, which is why it is the standard form of electricity delivered to homes and businesses. Understanding alternating current is essential for anyone studying electronics, as it lays the groundwork for more complex concepts in electrical engineering and physics.