Electricity can flow either as direct or alternating current, and is used in homes to power electrical appliances.
What type of current does a mobile phone battery produce?
What is the size of mains voltage Northern Ireland?
What colour is the live wire?
Green and yellow
Which wire is connected to the fuse?
What is the position of the neutral wire in a plug?
What is the purpose of the earth wire?
If there is a fault, the earth wire provides a low resistance path to earth
The earth wire is needed to make the appliance work
If the neutral wire fails, the earth wire can take over
What is the purpose of a fuse?
A fuse is designed to stop the wires being pulled out of a plug
A fuse is designed to melt if the earth wire becomes loose
A fuse is designed to melt if the current becomes too high
Use the following electricity meter readings to calculate the cost of electricity used by a school.
Previous reading = 37170 kWh.
Present reading = 41217 kWh.
Units at 14.78 p per kWh.
What is the cost of using a 3 kW heater for 9 hours if the price of a unit is 15 p?
A microwave has a power rating of 800 W. What size fuse should be used in the plug if the mains voltage is 240 V.