Which term describes a circuit where the current can only flow in one direction?

A DC circuit, or Direct Current circuit, specifically refers to a configuration where the electric current moves in a single direction. This characteristic is fundamental to how DC circuits operate, typically utilizing sources like batteries or DC power supplies. In these circuits, the flow of electrons travels consistently from the negative terminal to the positive terminal, enabling predictable and stable power delivery for devices that require a unidirectional current.

In contrast, an AC circuit (Alternating Current circuit) allows current flow that alternates direction, making it unsuitable for describing a circuit limited to one-direction flow. Open circuits are incomplete paths for current flow due to breaks or interruptions, while closed circuits provide a complete path for current to flow freely, but they do not stipulate the directionality of the current flow. Thus, the defining characteristic of a DC circuit being strictly one-directional affirms its distinction and correctness in this context.