Which statement describes a circuit that periodically reverses current direction?

Which statement describes a circuit that periodically reverses current direction?

• A. A DC circuit
• B. A load
• C. AC circuit
• D. A power supply

Answer: (C)

The main idea is that alternating current systems have current that changes direction over time. In an AC circuit, the voltage from the source varies with time (often in a sinusoidal way), so the current flows first in one direction and then in the opposite direction, repeating at a set frequency. This back-and-forth flow is what characterizes AC as opposed to direct current, which travels in only one direction. A load is simply a device that consumes power, not a description of current direction. A power supply is a source that can produce either AC or DC, but the feature of periodically reversing current direction specifically describes an AC circuit. Frequency governs how many reversals occur each second (for example, 60 Hz in some regions).

The main idea is that alternating current systems have current that changes direction over time. In an AC circuit, the voltage from the source varies with time (often in a sinusoidal way), so the current flows first in one direction and then in the opposite direction, repeating at a set frequency. This back-and-forth flow is what characterizes AC as opposed to direct current, which travels in only one direction. A load is simply a device that consumes power, not a description of current direction. A power supply is a source that can produce either AC or DC, but the feature of periodically reversing current direction specifically describes an AC circuit. Frequency governs how many reversals occur each second (for example, 60 Hz in some regions).