What color identifies the earth wire in a mains cable?

What color identifies the earth wire in a mains cable?

• A. Green and yellow
• B. Blue
• C. Brown
• D. Red

Answer: (A)

Color coding helps you identify wires quickly. The earth conductor is the protective one and is green-and-yellow striped. It provides a low-resistance path to earth if something faults, so metal parts stay at earth potential and the fuse or circuit breaker trips to cut the supply. It normally carries no current during normal operation. Live and neutral use other colors (brown and blue in modern wiring, with red used for live in older systems), which is why green-and-yellow is set aside for earth.

Color coding helps you identify wires quickly. The earth conductor is the protective one and is green-and-yellow striped. It provides a low-resistance path to earth if something faults, so metal parts stay at earth potential and the fuse or circuit breaker trips to cut the supply. It normally carries no current during normal operation. Live and neutral use other colors (brown and blue in modern wiring, with red used for live in older systems), which is why green-and-yellow is set aside for earth.