Watt's Electricity - Electromagnetism Circuit Basics

Here we have a very simple circuit, but its important we understand what makes up a circuit before be move on to more complex ones.

Video

Board Image

Tutorial (for when you are with the board)

Part 1

Look at the board, on it is a simple electrical circuit, let’s go through the different bits of it - what we call the components!

Every circuit will have something that provides the electricity, in this case it’s a battery. All batteries have two places where we connect the circuit.

See the metal wire by the top of the battery, we call this a conductor and it can carry electricity. You can think of it as a pipe through which water flows, it’s not exactly the same, but similar in many ways.

The next component in the circuit is a light unit, this is called the load – it's what the circuit is doing! The conductor comes out and goes round to the last thing in the circuit, a push button switch. Then there is a connection from the switch back to the battery. It’s really import that the circuit get back to the other end of the battery. At the moment the switch means that there is a gap in the circuit so nothing is happening, but if you press the button and hold it down, that gap will be closed and electricity will start to flow around the circuit which will turn the light on.

Part 2

Every circuit will have something that provides the electricity, in this case it’s a battery which uses chemicals to generate the electricity. Later we will see that other gadgets and things that can also produce electricity.

In this circuit it’s a thin piece of copper which is used to connect the components. Most metals will conduct electricity, but copper is used most of the time. All the wires in your home connecting the light and plug sockets will be made of copper. Note that the ends of the battery are labelled positive which is marked with a + sign and negative which is marked with a – sign. Convention says we think of the electricity flowing from the positive and round through the circuit to the negative.

To Try

Find something metal (like a paper clip) that you can use to connect the two copper wires either side of the switch. If you get this right, then the light will come on as you are by-passing the switch.
Very carefully try unscrewing the bulb a little, you will find that it will not work as the contact on the bottom with disconnect. This is another way the circuit can be made incomplete.

Follow-Up Ideas

Very carefully take a torch or bicycle light apart and try ans identify the parts of the circuit - you are looking for the switch, battery, bulb and the metal or wire that connects them.
Take the batteries out of a remote control and look at the metal points where the batteries connect. Note that there is always a spring connecting to the flat end of the battery. This adds pressure to ensure that both ends of the battery are always touching the metal ends. This is because if the battery was loose and came away from the metal for a short time the remote control would stop working.