Final answer:
The neutral wire carries electrical current back to the power source in a circuit and is usually identified by white colored insulation, although this can vary with regional standards.
Step-by-step explanation:
The neutral wire is a critical component of a household electrical circuit, which carries electrical current away from a device and back to the power source to complete the circuit. It is typically identified by white colored insulation. However, it's important to note that wire insulation color codes can vary by region. Therefore, while the neutral wire may commonly be white, it's essential to verify the local standards to determine the correct color code for your area.
Within the standard three-wire system, two connections to earth on the neutral wire ensure that it is at zero volts relative to the ground. This makes the wire safe to touch, even if the insulation is missing. The third connection to earth is made to the case of the appliance through the ground wire, typically green or yellow, ensuring the case is also at zero volts.