Oklahoma Electrical Practice Exam

What color identifies an ungrounded wire?

1. Red

2. Blue

3. Black

4. Green

The correct answer is: Black

In electrical wiring, the color black is commonly used to identify an ungrounded (hot) wire. This standardization helps in maintaining uniformity and safety in electrical installations. Hot wires carry voltage and can pose a risk of electric shock if handled improperly, so recognizing them by their standardized color is crucial for both electricians and anyone who may be working on or around electrical systems. The choices of red and blue may also represent hot wires in certain situations, particularly in three-phase systems, but black is the most universally acknowledged color for ungrounded conductors. The green wire indicates grounding, which is essential for safety by providing a path for fault current. Understanding these color codes is essential for anyone involved in electrical work, as it promotes safe practices and helps prevent accidents.