What it shows
Electricity flows only round a complete loop. The switch opens and closes the loop, turning the bulb off and on.
This idea has a short entry only. For the science behind it, read the sentence above with your textbook and ask your teacher to explain the law or idea it shows, so you can describe it in your own words.
Materials
- Two AA cells in a holder
- A 2.5 V torch bulb in a holder (an LED can be used instead, but only with a 100 ohm resistor in series and its longer leg towards the positive end of the cells)
- Insulated wires
- A switch, or one made from a drawing pin and a paper clip
- A cardboard base
Safety
For this project: Use cells only, never a mains socket. Do not join the two ends of a cell directly with a wire: it gets hot.
Never use mains electricity: power models with cells, batteries or a low-voltage adapter. Sharp and hot tools, flames and lab chemicals need an adult or your teacher beside you. Keep magnets, button cells and small parts away from young children, and wash your hands after making.
How to go about it
Numbered steps have not been written for this idea yet. Plan it with your teacher: sketch the design with measurements, build one part at a time, test each part, and write every observation with the date. The free ebooks below have step-by-step projects of the same kind.
Take it further
Put different objects in the gap to find out which are conductors and which are insulators.
Change one thing, measure what happens, and add a table or chart of your readings: that is what turns a model into your own investigation.
Free ebooks for this project
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Electricity and Magnetism Experiments
Hands-on experiments with cells, wires, bulbs and magnets
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Easy Science Projects for Class 1 to 5
Simple, safe projects young children can make with a little help
Find out more about physics
Free, well-known places to explore the subject further. Ask a grown-up before you sign up for anything or type your name anywhere.