GCSE Physics Unit 2 Revision (11)

Fuses and Earthing

• Mains Cables have 3 separate wires.
• The brown live wire in a mains supply alternates between a high positive and negative voltage. 
• The blue neutral wire is always at 0V.
• Electricity only flows in and out through the live and neutral wires normally.
• The green and yellow earth wire is just for safety, and works together with a fuse to prevent fire and shocks.
• Fuses prevent electric shocks.
• To prevent surges of current in electrical circuits and danger of electric shocks, a fuse is normally placed in the circuit. You can sometimes use a circuit-breaker, which is like a resettable fuse.
• If the current in the circuit gets…