P5 Flashcards
Why use brass in a plug
Because it is a good conductor it does not rust or oxidise, harder than copper
Why use a plastic case for a plug
Good insulator, shaped so wires and pins cannot touch each other
Why use copper in a plug
Good conductor, is flexible so wire can be bent without breaking
Why use a fuse in a plug
Safety feature if current is too powerful fuse will melt and cut the power
What colours are in a cable
Brown, blue, green and yellow
What is the brown wire
Live wire, carries current to the appliance at a high voltage
What is the blue wire
Neutral wire, completes the circuit and carries current away from the appliance
What is the green and yellow wire
A safety feature and connects the metal case of an appliance to the earth to stop the appliance becoming live
What is the function of the fuse in a plug
Melts and breaks the wire the circuit is broken so it stops working
What is cable grip
Clamp over the cable to keep it in place, should be behind the cable to keep it in place
3 core cable
Metal case
Earth wire connected to the longest pin
If live wire touches case it is earted and the case does not become live itself
What is a short circuit
When a live wire touches a neutral wire a huge current passes through the circuit and the fuse blows
What happens if you touch a live wire
A massive voltage will flow through your body which will be lethal
What are pins made of in a llug
Brass
Why would you need only a 2 wire plug for a phone charger
Because there is plastic casing
