| Energy & Forces - Properties & uses of energy - Electricity - G13 |
  Teacher's Guide
EF-C1.4 |
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1. Worksheet C12a (G) can be used for the children to write down all the electrical items they can think of in their homes and to note whether the item is powered by mains or battery. Less able children could draw the items and a symbol for battery or mains. |
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3. A good way to start this lesson is to give out two wires, a battery and a bulb to each pair or group of three children. Give them a short time to try to make the bulb light. Look at the arrangement made by a successful group and let everyone else copy it. Draw the successful arrangement on the board.
There are two ways the children could find :-
The important thing to notice about this is that the electricity must be able to go in a loop. We call this loop a circuit. A bulb has two points where the electricity can go in and out. One is the metal case and the other is the grey blob at the base. We call these points the terminals. The battery has two terminals as well - the blob at one end and the metal case at the other. The electricity must go from one end of the battery to the case of the bulb and from the blob at the end of the bulb back to the other end of the battery. It helps at this point to look more closely at what an electric current is. See Teaching Note - Electricity. |
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| Try not to use crocodile clips and bulb holders at this stage because they confuse what is happening. With simple wires and bare bulbs the children can see exactly what they are doing. Some children may think that the coloured plastic of the wire is carrying the electrons so point out the metal centre. Small bits of Sellotape can be used to hold wires in place if the children are struggling. | ||||
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Electricity
Electricity is a form of energy and it can be changed into heat energy, light energy and sound energy. It can also be changed into kinetic energy which is the form of energy used to make machines work. All things are made of tiny particles called atoms. Parts of atoms called electrons can travel from one atom to another and can carry electrical energy with them. It is these electrons travelling along wires which take the electrical energy from the battery to the bulb where it becomes heat and light energy but then the electrons have to travel back to the battery to get more electrical energy. |
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Activity - circuits
You can easily demonstrate this to the children as follows. Get the children to form a circle in the classroom (circuit) and place a tub of counters or cubes (battery) at one point beside the circle. Have one child to represent the bulb and stand next to the circle on the opposite side of the room from the tub. The children (electrons) walk around in the circle and pick up a cube (electrical energy) as they pass the tub. When they reach the ‘bulb’ they hand over the counter (energy) and the bulb can briefly light up (hold up a card or similar). When the tub (battery) runs out of counters (energy) the ‘bulb’ can no longer light - the battery is flat. The faster the children walk around, the faster the bulb will light until it appears to be lit all the time. If the circle is broken for any reason then energy will no longer reach the bulb and it will not light. |
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 4. To make a bulb brighter you can add extra batteries. Link the batteries end to end - blob end to smooth end and then put back into the circuit.
At this stage you can introduce battery holders, wires with crocodile clips and commercial switches to make these circuits easier to manage but point out to the children how the circuit is formed through these pieces of equipment. |
