NEIEP Mechanics Practice Exam

What color insulation is used to indicate a ground wire?

1. Black

2. Red

3. Green

4. Blue

The correct answer is: Green

Ground wires are designated with green insulation, which is a widely accepted standard in electrical wiring. This color coding is crucial for safety and functionality, as it allows for easy identification of ground wires, helping to prevent accidental connections that could lead to electrical shock or fires. Understanding the significance of color coding in electrical installations is essential for ensuring proper circuit design and maintenance. While other colors are used for various purposes—such as red for secondary hot wires or black for primary hot wires—green is exclusively reserved for grounding. This helps to maintain clear and consistent wiring practices across the industry, ultimately promoting safer electrical systems.