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Objective
This is one of those science fair experiments in which you will be testing different materials to find out which ones conduct electricity well.
Introduction
Electricity was known to exist since times when amber and fur was rubbed together by the ancient Greeks, resulting in the production of static electricity.
The first remarkable achievement in this field was by Alessandro Volta, an Italian physicist, who developed the first circuit in 1800. He also showed that a circuit must be closed, or complete, in order for electricity to flow through it. Science fair experiments can be conducted using circuits that demonstrate this principle.
Volta’s student, Georg Simon Ohm, made the next discovery in 1826. He observed that some materials did not allow electricity to pass through freely. In other words, they resisted the flowing of electricity through them. This resistance of a circuit is measured by a unit called ohms and is abbreviated by the Greek letter omega (?).
Some materials allow electricity to move through them whereas others do not allow it to move so well. Those materials which allow electricity to move through them are known as conductive materials. Those materials that resist the passage of electricity through them are called insulators. The resistance of conductive material is low whereas the resistance of insulators is high. In science fair experiments, we can use copper wire as a conductor and plastic coating as an insulator.
In this experiment different materials will be tested by you, to see whether they are insulators or conductors. You will figure out the same by attaching different materials to the circuit and making a note of how bright or dim the bulb is. You will be creating your own light bulb circuit for this purpose.
Materials
- paper clips, string, plastic, aluminum foil, rubber bands, etc…
- a battery (6V)
- 3 pieces of wire leads having alligator clips attached to both ends
- a light bulb (6V) with wires attached
- an insulating surface such as a chopping board that is flat
Procedure
- Create the circuit for testing the materials.
- Connect either terminals of the battery with wires. One end of the wire which is black should be attached to the (-) terminal and the free end to should be connected to the bulb lead.
- One end of the red colored wire should be attached to the (+) terminal and the free end should be left as it is for various materials to be attached.
- Attach the second lead of the bulb to one end of the yellow colored wire and leave the free end as it is for various materials to be attached to it.
- Now, the red colored and the yellow colored wire will be having one free end each. This is where the testing materials will be connected.
- In science fair experiments, data is always recorded. So draw a table with three columns to write the material type, the material source and the bulb brightness.
- Now connect the first piece of material to the circuit.
- Write down if the bulb lights up and how bright it is. Continue for all other materials.
- You can attach an Ohm meter and write down the readings in the table.
- Now make another table with three columns to write the names of conductors, poor conductors and insulators.
Note that when the bulb is bright, the material has high conductivity and low resistance, and should be written in the conductor column. When the bulb is dim, the material has low conductivity and goes in the poor conductor column. When the bulb does not light up, there is no conductivity and high resistance, and the material should be written in the insulator column. Now that you are excited about going ahead with this experiment, your next step would be to download a free copy of “Easy Steps to Award-Winning Science Fair Projects” from the link below right now.
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Source: http://ezinearticles.com/?Science-Fair-Experiments-That-Win-Awards—Project-12—Electrical-Conductors&id=1784349
