Background
Many people do not realize that electricity and magnetism are related. What that means is that magnets can be used to make electricity, and electricity creates magnetism. Essentially everything that operates via electricity gives off its own small magnetic field, and when the electricity stops, the magnetic field disappears.
Electricity is created when charged particles move. For this activity, the electrons (-) will be moving through the wire, creating current. Voltage is the muscle behind the current, pushing the electrons along a circuit so that we can create electricity. If the circuit is broken, the electrons cannot travel and there is no electricity.
But if there is another path available, the electrons will take it to continue the circuit. When the electrons have multiple paths that they can use, this is called a parallel circuit.
In this exercise, you’ll combine these three items to form an electric current and light the lightbulb.
Why do this in your classroom
- To allow students to manipulate variables and record changes
- To give students an opportunity to create their own circuit
- By allowing multiple correct answers, this shows that a scientific principle can be discovered in more than one way
Materials
- One battery (D or C)
- One small piece of aluminum foil (about 12 inches by four inches should be enough)
- One flashlight bulb (available for about a dollar at most hardware stores)
Procedure
- This is an open-ended activity. There are multiple correct solutions. The foil should be twisted into a wire. Any correct solution will involve a connection that goes battery-foil-lightbulb-battery. The connections on the battery and the lightbulb can vary, as long as each connection is made on a unique part (the + and – end of the battery; the side and bottom of the bulb).
- Try changing the orientation of the battery and see what happens.
- Add a second battery and see how that affects your lightbulb.
- Add a second piece of foil and second lightbulb and try it again. With additional pieces, the circuit created can be either series or parallel. If there is only one path for the electrons to flow through, it is series. If there are multiple paths, it is parallel. What is the difference in the brightness of the lightbulbs between the two circuits?
What’s happening
Electricity needs a simple circuit in order to flow. This can be done by connecting the metal parts of the wire, lightbulb and battery. When there is a clear path for the electrons to flow through, electricity is created and maintained as long as the circuit is complete and the battery has voltage. Adjusting the voltage of the battery is one way to vary the amount of electricity flowing. Use other variables to see what increases and decreases the current.
For more information contact MagLab educator Carlos Villa.
