Everyone finds Electricity fascinating even though it may be difficult to understand at times.

In order to make successful circuits you must get organised and try to keep things neat and tidy otherwise it is very easy to get mixed up and difficult to see where things are going wrong.

A jumble of long wires tangle up on the desk is a bad way to introduce the topic of electricity.

A common mistake which prevents all circuits from functioning is to allow ‘short circuits’. This is when the bare ends of wires or croc. clips touch where they are not supposed to and allow electricity to flow along a path leading directly back to the battery - this quickly flattens the battery and spoils further circuits.

How does a switch work?

Try using some paper fasteners to make a switch and this will hep explain what is inside a switch and how it ‘makes’ and ‘breaks’ a circuit.

An important thing to note is that paper fasteners are made from a metal. Metals are important in circuits and switches.

Here is an excellent way to make a switch.

One fastener has been pushed into the foam base and is connected to a croc. clip wire. The other fastener has had one leg bent outwards and the other pushed into the foam and connected to another croc. clip.

Push down on the raised up leg and this makes it touch or ‘make contact’ with the other fastener.

This completes the circuit and makes the bulb light up. Switches contain a fixed and a moving metal contact which together can complete a circuit. We provide the force to make the contacts close together.

When we know some science it’s great fun to invent and solve problems.

How do ships at sea at night know which lighthouse they are approaching? Ans. each one has its own special sequence of flashes.

Flashes of light have been used to send messages for thousands of years eg. reflections from a soldier’s shield or signal fires in ancient times.

We can send messages using Morse Code.

A better way to send Morse Code messages is using a buzzer but we need to find out something about the buzzer first.

In this circuit the buzzer has replaced the bulb but it does not work.

Have a close look at the colour of the buzzer wires.

Buzzers are not like bulbs - they will only work one way round in a circuit and the red and black wires help us tell which way to connect them.

Have a close look at the battery also.

It has a plus (+) mark at one end and a minus (-) mark at the other.

The red wire of the buzzer must connect to the plus terminal of the battery or it will not work.

This is why it was important earlier to try the bulb and switch in different orientations. All ‘components’ are not the same and assumptions can lead to confusion.