Electricity in homes is an alternating current and is used to power electrical appliances. In a plug the wires are colour-coded and a fuse is included as a safety device in the circuit.
What type of current does an electrical cell produce?
What is the mains voltage value in this country?
What is the frequency of mains electricity?
What colour is the live wire?
Green and yellow
Which wire is connected to the fuse?
Which is the correct description of the earth wire?
A high resistance path to ground
A low resistance path to ground
A negative resistance path to ground
What is the purpose of the earth wire?
If there is a fault, the earth wire provides a path for high currents to go to ground
The earth wire is needed to make the appliance work
If the neutral wire fails for some reason, the earth wire can take over
What is the purpose of a fuse?
A fuse is designed to stop the wires falling out of the plug
A fuse is designed to melt if a wire becomes loose in the circuit
A fuse is designed to melt if the current gets too high
A microwave has a power rating of 900 W. Calculate what size fuse should be used in the plug if the mains voltage is 230 V.
A TV has a power rating of 750 W and the plug connected to the 230 V mains has a 3 A fuse. Once the TV is turned on, the fuse melts, why has this happened?
The wires came loose
The current was too big due to a fault in the circuit
The fuse was the wrong rating