Electricity can be very dangerous if not used properly. At home, mains electricity is used, which has a much higher voltage than the cells used at school. It can be extremely dangerous.
The general safety rules when handling electricity are:
- never touch the metal parts of plugs (see a plug inserted into a socket in the diagram)
- never poke things into sockets
- keep water away from electrical appliances (water is a conductor of electricity).
In science lessons:
- always show your circuits to your teacher before switching them on
- switch the current off before changing your circuit.
Electricity can be controlled by using a switch. When the switch is open, there is a gap in the circuit, so electric current cannot flow. When we close the switch there is a complete circuit for the current to flow around. The diagram shows a complete circuit with an open and then a closed switch. In science, we call the battery a cell, but actually a battery consists of many cells in a row.
All wires are metal, because metals conduct electricity, but they are covered in plastic to insulate us from the electricity and so avoid accidents. Have a look at the wires this plug contains:
You can see the differently-coloured wires for Earth (yellow/green), Live (brown) and Neutral (blue). As almost all appliances come with a fitted and sealed plug, it's not as vital to learn how to wire a plug as it once was.