What defines an electric circuit?

An electric circuit is fundamentally defined as a closed loop that permits electric current to flow. This closed loop is composed of various components, such as wires, resistors, capacitors, and power sources, which collectively facilitate the movement of electrons. When the circuit is complete—meaning there are no breaks in the path—the current can flow continuously, enabling electrical devices to operate.

Proper understanding of an electric circuit emphasizes that it must be a closed loop; if there are any interruptions in the path, such as a disconnected wire or a broken component, the flow of current is halted. This concept is essential in electronics and electrical engineering, as it underpins how devices function, from simple circuits to complex systems.

Other options do not accurately define what an electric circuit is. While one speaks about energy and another addresses resistance in materials, these concepts are related to electricity and circuits but do not describe the fundamental nature of a circuit itself. The option discussing a system that converts electrical energy into thermal energy refers to applications of circuits in devices like resistors or heaters but does not capture the concept of what constitutes a circuit.