by Alan Zisman (c) 2003
Electricity works when tiny particles called electrons (which are part of an atom) move in a circuit-- a complete path from an electrical source like a battery through a load -- the part like a light bulb or a buzzer or a fan.
Electricity move easily through conductors. Insulators don’t let electricity move through it easily. Metals are good conductors.
We’re going to use a computer program, the Virtual Electricity Lab to make a circuit, and test various materials to see if they are conductors or insulators. Open the Virtual Electricity Lab... you’ll see something like this:
You drag the parts you want from the left side to the green area at the right... connect them with wires (when the little green hand is selected). To remove a part, click on the wirecutter icon, then click on the part that you want to get rid of.
A. Make a simple circuit.
You will need
the following parts:
- a 1.5 volt battery
- a Christmas tree light bulb (any colour)
- a switch
Click on the little switch icon (in the left-hand part of the screen), then you can flip the switch on... make sure the light bulb lights up. If the light bulb lights up, you made a complete circuit. Turn the switch off.
1. What happens to the light bulb when you turn the switch off?
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2. Why? (Hint: do you have a complete circuit anymore? Can the electrons get back to the battery?)
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With the switch off: Remove the wire on the right-hand side. Click on the Other items on the left side, and scroll down to find the wax crayon. Add a crayon to the circuit, adding wire to connect everything together. Turn the switch on.
3a. Does the lightbulb light up? _____
b. Is wax a conductor or insulator? _______________
Replace the crayon with a rubber eraser, and test your circuit.
4. Is rubber a conductor or insulator? _________________
Replace the eraser with a piece of paper and test your circuit
5. Is paper a conductor or insulator? ___________________
Replace the paper with a block of wood and test your circuit
6. Is wood a conductor or insulator? ___________________
Replace the wood with the plastic spoon and test your circuit
7. Is plastic a conductor or insulator? ___________________
Replace the spoon with the scissors and test your circuit
8. Is the scissors a conductor or insulator? ___________________
Replace the scissors with the paperclip and test your circuit
9. Is the paperclip a conductor or insulator? __________________
10. Fill in the table below, first predicting whether you think the items will be conductors or insulators, then testing to see if your predictions are correct:
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11. Most of the conductors have something in common. What do you think it is?
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Be able to define the following electricity vocabulary words (they may be on your test for this unit):
a) electron ______________________________________________________