P2.4 - Using mains electricity and the power of electrical appliances Flashcards
What is direct current?
Current that always flows in the same direction, supplied by cells and batteries
What is alternating current?
One which is constantly changing direction
What is the frequency of mains electricity?
50Hz
What is the voltage of mains electricity?
230V
What are most electrical appliances connected to the mains using?
A three-pin plug
What are the three wires in an electrical cable?
- Earth (Green and Yellow)
- Neutral (Blue)
- Live (Brown)
What is the function of the Earth wire?
A safety wire to stop the appliance becoming live
What is the function of the Neutral wire?
Completes the circuit
What is the function of the Live wire?
Carries the high voltage
Which way does each wire go in a plug?
bLue goes Left
bRown goes Right
sTriped goes Top
What is the difference between a two core cable and a three core cable?
A two core cable does not have an earth wire
What materials are used to make three-pin plugs?
- Copper for the wires - it is a good electrical conductor
- Plastic for the plug outer - plastic is a good insulator
What happens if an electrical fault causes too great a current?
The circuit is disconnected by a fuse or circuit breaker in the live wire
What happens when the current in a fuse wire exceeds the rating of the fuse?
It will melt, breaking the circuit
What are RCCBs?
Residual Current Circuit Breakers
