What is the primary function of a neutral wire in an electrical system?

The primary function of a neutral wire in an electrical system is to carry current away from the outlet back to the source, allowing for a complete electrical circuit. In a typical AC (alternating current) circuit, the neutral wire provides a return path for current that has flowed through the load (like a light bulb or appliance). It ensures that electricity flows properly and safely by balancing the electrical load and completing the circuit. This is fundamental in maintaining the system's functionality and safety.

While other options highlight important aspects of electrical systems, they do not accurately describe the function of a neutral wire. For instance, the notion of the neutral wire being a direct connection to the power source misrepresents its role, which instead is to return current, not serve as a primary power conduit. Similarly, the idea of it acting as a backup in case of failure or detecting overloads relates more to safety features or protective devices within electrical systems, rather than the function of the neutral wire.