Light It Up
Make an electrical circuit to light a bulb Suitable for kids aged 7+, with adult supervision
- The light globe is glass and misuse may cause it to break, resulting in sharp pieces that could cut skin. Use carefully.
- Do not hold the wire on the battery for long periods without removing it. The wire and/or battery terminal may get hot.
- Small globe
- Globe holder
- Short electrical wire x 2
What to do:
- Screw the light globe into the holder.
- Attach the end of a stripped piece of wire to one side of the globe holder, by threading it through the metal hole and twisting it in on itself to hold it in place. The copper wire (not the plastic coating) needs to be in contact with the globe holder for electricity to flow and power the bulb.
- Attach the end of another stripped piece of wire to the other side of the globe holder following the step above. See picture. Masking tape can be used to secure the wires further.
- Hold the free ends of both wires to a battery, making a circuit (electricitys pathway). One wire to each battery terminal. Does the bulb light up? Why? What happens if you take one of the wires away from the battery?
- As a further challenge you may like to think of a way to connect the wires to the battery without holding it with your fingers. The use of paper clips and masking tape could be a starting point
Why is it so?
The bulb lights up and works, because electricity flows through it. The current (or flow of electricity) moves from the battery through the wire to the globe, then back through the second wire to the battery. This is called a circuit, a path electricity can run along. Electricity only flows if there is no break in the circuit.
When one of the wires is taken away from the battery, electricity stops flowing and cant power the globe. This could be thought of as a very simple switch.
Most circuits contain switches. When the switch is on there is a complete circuit and electricity will flow. When it is off there is a small break or gap, and electricity cant pass through the air in the gap to complete the circuit. The word circuit comes from the word circle you can understand why!
Globes, globe holders and wire are available from the science supply section of this website.