10. P5 Mains Electricity Flashcards
What is meant by the frequency of an AC supply?
The number of cycles per second.
What is the frequency of mains electricity in the uk?
50 Hz (50 cycles per second)
What two wires do every device connected to the mains have?
Live wire and neutral wire
What type of current is the mains electricity?
A.C. (alternating current)
Potential Difference of the mains supply?
230 V
Maximum value that the PD reaches in the mains supply of the UK?
325V
What type of current is produced by a battery?
Direct current
Describe what is meant by a direct current?
Current flows only in one direction only.
What does a fuse do in a plug?
Protects the user, melts if too high a current flows through it, breaking the circuit.
What colour is the live wire?
Brown
What colour is the neutral wire?
Blue
5 safety features of a 3 pin plug?
Fuse, Earth wire, Cable grip, colour coded wires, hard plastic coating.
What devices in the UK require an earth wire?
Devices with a metal casing.
What colour is the earth wire
Green and yellow (stripes)
How does the earth wire protect the user?
Earth wire is connected to the casing. If fault develops making the casing live, the earth wire provides a route back to socket.