Current Electricity is caused by tiny invisible things called electrons that move through metal. This flow is called an electric current. Objects that need current electricity (moving electricity) are powered by batteries or by electricity which travels along wires from a power station. The circuit is completed by a switch, which turns the appliance on. When the switch is turned off, the circuit is broken and the appliance is turned off.
Many objects that we use in our every day routine are powered by electricity from computers and hairdryers to lamps and washing machines. Lights us mains electricity, and so do things like cookers and television. Mains electricity has a higher voltage than cells and can therefore be dangerous.
Conductors allow electricity flow through them. Conductors are materials that can carry electricity - they conduct electricity. Metal materials such as copper, iron, steel and aluminium are all good conductors of electricity. Therefore metals are good electrical conductors.
Insulators do not allow electricity to flow through them. Materials such as wood, plastic, rubber and glass do not carry electricity and are called insulators : they don't conduct electricity.
Insulators and conductors both have important uses in current electricity.
Electricity can be very dangerous. You should never touch anything electrical with wet hands and that includes any electrical switches. Electricity can be conducted through sweat (salty water) to your body, giving you an electric shock - so think before you touch.
- The moving electricity is called an electric current
- The current is the amount of electricity that is flowing around the circuit
- The current is the amount of electricity that is flowing around a circuit.
- We measure the current using an ammeter. The units for current are amps (A).
- An electrical cord has a plastic coating which is the insulator
- Inside the plastic cord are copper wires which are the conductors
- The glass of a light bulb is the insulator (bulb)
- The wires inside the glass light bulb are the conductors of electricity.
- The surface (wooden, glass or plastic) where you switch on and where the light bulb is inserted are the insulators.
- Never touch the bare metal parts of plugs.
- Never poke things into sockets.
- Keep electricity away from water.
- Do not plug too many things into one socket.
- Never use something that has a damaged wire.
- Stephen Gray (1666-1736) was the first person to discover that electricity can flow through wires.
It is important to learn about electricity so that you don't get shocked.
