What type of circuit allows current to flow in only one direction?

The type of circuit that allows current to flow in only one direction is a direct current (DC) circuit. In a DC circuit, the flow of electric charge is unidirectional, meaning that electrons move consistently in one direction from the positive terminal to the negative terminal. This is a fundamental characteristic of DC circuits, contrasting with alternating current (AC) circuits, where the direction of current changes periodically.

DC circuits are commonly used in a variety of applications, such as batteries, solar panels, and electronic devices, where consistent voltage is required for proper operation. Understanding the nature of current flow in DC circuits is essential for designing and troubleshooting electrical systems that rely on this type of power source.