What it shows
A complete circuit with a cell, a bulb and a switch makes light. A lighthouse model shows how light guides ships at night.
The science
A circuit is a closed loop for current from the cell, through the bulb and back. A switch is a gap we can open or close. When the paper clip touches both pins the loop is closed and the bulb lights. A lighthouse light can be seen from far away and warns ships of rocks.
Materials
Cost: under Rs 200. Many items come from home or from waste; spare parts such as LEDs, motors and wire are in the store.
- A cardboard tube or a rolled chart paper (free)
- One 1.5 V cell and a bulb with holder (under Rs 50)
- Two pieces of insulated wire
- A paper clip and two pins for a switch
- A cardboard base
- Paint and tape
Safety
For this project: An adult must strip the wires and press the pins. Use only a small cell, never mains power.
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.
All the safety rulesStep by step
8 steps. Do them in order, and test each part before you go on to the next. Write what you notice in a notebook as you go.
Paint the tube in red and white stripes and let it dry.
Stand the tube on the base and fix it with tape.
Fix the bulb holder at the top and run the wires down inside.
Make a switch on the base using two pins and a paper clip that you can turn to touch both.
Connect one wire from the bulb to the cell and one to the first pin.
Connect another wire from the second pin to the other end of the cell.
Turn the clip to close the switch and see the lighthouse glow.
Darken the room and show how a ship would see the light.
What you should see
The lighthouse glows when you close the switch and goes dark when you open it.
Viva questions
A teacher or a judge will ask how it works. Try to answer each question before you open it, then compare.
1What does a switch do?
It opens or closes the circuit.
2Why does the bulb light?
Current flows through it in a complete loop.
3Why do ships need lighthouses?
To avoid rocks and find the coast at night.
4What is the source of energy in your model?
The cell.
Take it further
Add a second bulb in the circuit and see if both are as bright.
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
Science projects
Easy Science Projects for Class 1 to 5
Simple, safe projects young children can make with a little help
Science projects
Electricity and Magnetism Experiments
Hands-on experiments with cells, wires, bulbs and magnets