NEC Commercial Electrical Practice Test

How should the terminal intended for connection to the grounded conductor be identified on receptacles, plugs, and connectors?

1. Red

2. Blue

3. White

4. Green

The correct answer is: White

The terminal intended for connection to the grounded conductor must be identified by the color white. This identification is consistent with the National Electrical Code (NEC), which specifies that the grounded conductor—commonly referred to as the neutral conductor—should be marked with white or gray insulation. The significance of using white for the grounded conductor is primarily for safety and to ensure correct installation. It helps prevent confusion during wiring and maintenance, as white is universally recognized as the standard color for neutral conductors in residential and commercial applications. Electricians and inspectors can quickly identify which terminal is meant for the grounded conductor, thereby reducing the risks of electrical faults or accidents. It also helps maintain uniformity in electrical installations across various devices, making it easier to troubleshoot issues when they arise. While colors like red, blue, and green have specific meanings in electrical work—red and blue are commonly used for hot wires in multi-wire circuits, and green is designated for grounding conductors—they do not apply to the identification of terminals for the grounded conductor. Therefore, the use of white is crucial for promoting safety and standardization in electrical systems.