Electrical Circuits
Electrical circuits are fun to make, and easy to understand. In this article we will build on the "Introduction to Electricity", by furthering our circuit work.
First, let's continue our study of current. We have already learned about resistance, and conductors. A wire's resistance is determined by the type of wire, thickness of the wire, and the length of the wire. A conductor is a material that allows the electrons to flow freely through it. An example of a conductor is any metal. A non-conductor resists or does not allow for the flow of electrons. An example of a non-conductor is rubber. Silver and copper are excellent conductors of electrical current. Although silver is a superior conductor, copper is used often in wiring, since silver is so expensive.
The thickness of a wire determines how many electrons can pass through it at a time. The thicker the wire, the greater number of electrons are able to pass. A thin wire results in more resistance for the electrons, due to nature of it's size. Think of it this way. A large funnel can allow much more liquid to pass through it, compared to a tiny funnel.
The length of the wire also effect the flow of electrons. The longer the wire, the more resistance electrons must deal with. Compare this to jogging. A runner will have an easier time reaching their destination, if the course is only 1/2 mile long, in contrast to the course being a 10 K race.
Basically, a thick, short, silver wire will conduct electricity better than a long, skinny, copper wire. Either wire will conduct electricity better than a rubber tube. The better the conductor, the easier it is for the electrons to flow. Flow equals current. A strong current mean there is a good flow of electrons.
You might want to perform the experiment from the introduction to this series again, by making a simple circuit. Than try some variations:
You will need:
- 2-9 volt batteries
- coated wire
- 2-small light bulbs - Radio Shack and other electronic stores carry them with wires already attached to them
- 2 battery connectors for a 9 volt battery- again Radio Shack will have these. They look like the kind of connector in kids toys, the ones you attach the battery to, to make the toy operate.
- a sharp knife
- adult supervision
Directions:
- Cut four pieces of wire, in various lengths.
- With an adults help, strip the ends of the wire, to expose about 1 inch of the metal inside.
- Attach one end of the wire to the light bulb. Attach the other end to the battery holder.
- Now attached the other wire to
Go To Page: 1 2
