Physics 1.4

• kW>W =x1000

  hours>seconds =x3600

  hours>minutes =x60
• in a ring main circuit the current travels two ways so you can make the wires thinner and have lower current in each part and you can add more sockets anywhere on the ring and each will have the same voltage
• live wire carries current into the house at a high voltage
• Earth wire carries no current when operating normally
• Neutral wire completes the circuit and has the same current as the live wire but a lower voltage
• Fuse stops the current if it becomes too large by melting a wire in the fuse.
• Miniature circuit breaker(MCB) stops current if becomes too large. it reacts more quickly and can be reset
• Residual current circuit breaker(RCCB) stops the current if The current in the neutral wire is different to the live wire. it reacts to a very small difference and reacts quickly. it will protect the user.