Which condition must be met for a circuit to be considered complete?

For a circuit to be considered complete, a fundamental requirement is that the current must have a defined path to ground. A complete circuit allows current to flow uninterrupted from the power source, through the conductors, and back to the ground or neutral. This path is essential because without a return path, the circuit cannot function.

The defined path to ground serves as a reference point for the electrical system and helps maintain safety by providing a route for fault currents to dissipate. Moreover, a proper ground connection prevents the buildup of voltages that could lead to electric shock or equipment damage.

While having all switches closed, connections to a load, and appropriate voltage levels are important aspects of circuit functionality, they do not solely determine whether a circuit is complete or operational. The critical aspect is ensuring the current has a definitive return path, which is achieved by establishing a connection to ground.