Physics – 4.4 Electrical safety | e-Consult
4.4 Electrical safety (1 questions)
Login to see all questions.
Click on a question to view the answer
The three wires in a mains circuit have distinct functions:
- Live Wire: Carries the electrical current from the power source to the appliance. It has a potential difference (voltage) relative to the neutral wire.
- Neutral Wire: Provides the return path for the electrical current, completing the circuit. It is typically at or near zero potential.
- Earth Wire: Provides a safe path for electrical current to flow back to the power source in the event of a fault (e.g., a live wire coming into contact with the metal casing of an appliance).
The earth wire is a crucial safety feature because it ensures that if a fault occurs and the appliance casing becomes live, a large current will flow through the earth wire. This large current will quickly trip the circuit breaker or blow the fuse, disconnecting the power and preventing someone from receiving a dangerous electric shock. Without the earth wire, the metal casing of an appliance could become live, posing a serious safety hazard.