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Activity 2: Electricity and electric currents Strategies

Read the information and then answer the questions.

Electricity
Electricity carries electrical energy and, as you have seen, electrical energy can change into other forms of energy.

Electrical energy can change into light energy when it flows through a lamp. It can change into heat energy in an electric toaster. It can also change into other forms of energy.

Materials that allow electricity to pass through them are called conductors. Copper wire is a good conductor. Materials that do not allow electricity to pass through them are called insulators. Plastic is a good insulator.

What is an electric current?

To produce an electric current, three things are needed: a supply of electric charges (electrons) which are free to flow, some form of push to move the charges through the circuit and a pathway to carry the charges. The pathway to carry the charges is usually a copper wire.

The flow of electricity can be likened to a flow of water through a pipe. Water comes from the dam and is forced through a pipe by a pump or by gravity. The supply of water is the dam, the push is the pump or gravity and the pipe is the pathway.

Flow of electrons

Current flow in a simple circuit
The diagram shows the flow of the electric charges (electrons).


You could go to the following websites to see an animation of electrons flowing through a conductor.
http://www.school-for-champions.com/science/images/dc1.swf
http://www.school-for-champions.com/science/dc.htm
  1. Name some other devices where electrical energy can change into light energy, and change into heat energy.
  2. List some forms of energy, other than heat or light, that can be produced by using electricity. (Think of some electrical appliances you use.)
  3. What is a conductor and an insulator?
  4. Name several other materials that are conductors and several that are insulators.
  5. What are the three parts of this simple electric circuit?
    A simple electric circuit
  6. What is the purpose of each of the three parts?
  7. Name several devices other than batteries that are used as a source of electrical charges.
  8. Name several devices other than a light globe that use the electrical energy carried by the electricity.

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