Energy and Change Electricity Energy Light
Electricity > Electric circuits > Conductors or insulators Home

Activity 1: Conductors or insulators

Electric train overhead wires and insulators

The electrical wires above the electric train are supported by porcelain objects (see arrows). Do you know what they do and how they do it? They are called insulators.
What do insulators do?
What to use
Battery, globe, wires, range of materials to test.
What to do
  1. Construct a test circuit similar to the one shown in the diagram.
    Electric circuit - test
  2. Test a range of different materials by touching the loose ends of the circuit wires onto the surface of the material.
  3. Keep the ends of the wires about 1 cm apart.
  4. See if the light globe comes on.
  5. You could test some of the following: eraser, pen, badge, pin, paper clip, ruler, paper, coin, beaker, bench top, chair leg, skin, hair, scissors, air and a small piece of black pencil lead.
Classification
  1. In a table such as the one shown, classify the substances as either conductors of electricity or as non-conductors (often called insulators). Classifying conductors or insulators record
  2. Is there a pattern in the classification? What is it that conductors have in common? What is it that non-conductors (insulators) have in common?
  3. Is there an exception to that pattern?
  4. Think about devices in your house that use electricity.
    What do you notice about the metal wires that conduct the electricity from the plug to the device? Why are they like this?
  5. Suggest why screwdrivers that electricians use have plastic handles.
  6. What parts of a light globe are most likely to be insulators and what parts are conductors?
  7. What do you think is the job of the insulators on the electrical wires above the electric train?

Challenge
Why can a bird stand on an electric wire in the street without getting electrocuted?



Copyright  |  Disclaimer  |  Privacy notice