In this activity, we will decide whether or not a circuit will work. For example, whether it will light a bulb or make a fan work.

As you know, electric current flows because it is pushed by cells (or batteries). For the current to flow right around a circuit, there must be no gaps in it.

If the circuit has a switch in it, and the switch is open, that's a gap - no electric current will flow.

The green component in this circuit is a type of switch called a reed switch. Reed switches are switched on by magnets - bringing a magnet near to it will close the switch and allow electric current to flow.

So, in this activity, we are going to be checking whether or not a circuit is complete, allowing current to flow around it.

Remember: the higher the electric current, the brighter any lamps will be, the faster a motor will turn and the louder a buzzer will sound.

Does that make sense?