Electricity generation Part 2
Faraday torch or wind-up torch
These are available on the web or from MUTR (www.mutr.co.uk)
If the session is held during the summer, lawn mowings could be brought into the class for the children to feel inside. The mowings should be in a large clear plastic bag. The shape of this can be arranged so that the children feel that the grass is warm inside without needing to touch the grass. If the children are able to touch the mowings they should wash their hands immediately afterwards. See safety notes.
- Grass - It is essential that the grass is clean
- Large thin plastic bag
- Strong plastic bag to protect the thinner one during transit
Water wheel toy
- Toy water wheel for use in a sandpit or bath
- Large plastic bottle full of water
- Large washing-up bowl
- Kitchen roll or large sponge
A helper could be asked to hold the wheel above the washing-up bowl. Then pour water through the toy so that children can see the wheel turn. The funnel might help to direct the water onto the wheel.
Paper wind mills
Sufficient sets of the following for one per group of about 4 children
- Thick plastic straw, tube from old ball point pen or any narrow tubing
- Square of stiff paper – cut as in diagram (make the holes before the session)
- Paperclip or length of stiff wire - bent as in the diagram
- 2 buttons about 1 cm diameter or larger
- Electric fan
Cut a square of paper with sides approximately 20 cms long. Then cut as shown by the dotted lines and punch holes where shown.
Partially straighten a paperclip as shown.
To assemble the windmill:
Pass end ‘a’ of the paperclip first through -
1. A hole in a button
2. The 4 holes at the corners of the paper square
(The corners should be flexed towards the central hole without causing a crease.)
3. The hole at the centre of the paper
4. A hole in the second button.
Move these to the section of the paperclip labelled ‘b’.
Finally push the end ‘a’ of the wire down the plastic tube.
A photograph of an assembled windmill is shown in the PowerPoint presentation (2.6 MB).
The children should experiment blowing in different directions. Windmills could be held in front of an electric fan to spin them. (If a fan is available,) The fan could be switched off to emphasise that the windmill will not turn if the wind stops blowing.
Note: For classes of young children - assemble the windmills before the session.
Alternative activity using a propeller
- Propeller (e.g. with 5 inch blades - MUTR SEP CP2 002 )
- String or plastic covered wire
Thread propeller onto the string or wire and ask 2 volunteers to hold the ends and then ask a third child to blow the propeller so it turns. Blowing in various directions might be tried. This could be done in groups of 4 children, if so, then sufficient for a set for each group of children would be needed.
- Electric fan
If carried out as a demonstration, an electric fan could be used to simulate a wind.
- Large Solar Panel Unit (for example MUTR - SEP 051)*
or Solar Panel (SEP 050)* These have 2mm connectors.
- DC buzzer -1.5V (for example from MUTR - EP1 900)*
- 2 leads with 2mm connectors
- Any bright table lamp
* MUTR (www.mutr.co.uk)
Connect the solar panel to the buzzer. It probably will not sound. Shine light onto the solar panel and the buzzer will sound. If you move lamp closer to the buzzer it will sound more loudly.
Activity 19: extra
Also show a calculator powered by solar cells.
Many calculators have a small battery to provide power when there is insufficient light. If this is removed then it is more obvious how the solar panel works. Then placing a finger over the solar panel stops the calculator from working. This also demonstrates that solar cells that need light to work.