Switches

An electric current will only flow round a circuit if there are no breaks in the circuit.

A switch is a way of controlling the current.
Some switches just open or close.
Other switches can change the path of the current rather like points on a railway track.

A simple switch

In the circuit there is one battery, one bulb and one switch.

This type of switch can only control whether something is on or off.

It can either be open (a) or closed (b)

The two circuits (A and B) show you what happens.
If the switch is open the current can't flow and the bulb is off (A).
If the switch is closed current can flow round the circuit and the bulb lights up (B).

Two way switch

The next switch can change the path of the current. It has two contacts (c and d). It is called a TWO-WAY switch.

The circuits C and D show you how it works.

When the switch is in position c, bulb C lights.
When the switch is moved to position d bulb D lights.