New Experience #13: The Simplest Circuit

circuit with battery bulb and wireDid you know it’s possible to light a small lightbulb with just one battery and one wire?

When I taught fourth grade, I introduced our unit on electricity by having my students figure out how to do just that.  It is actually very simple, and some students figured out in minutes.  It took other students a half hour and a few hints to get it.

So, when I introduced this idea to Luke and Leah, I wondered how it would go over.  I’m glad to report it was a huge success.

kids simple circuitI set the materials on our kitchen table and told the kids to see if they could make their lightbulb turn on.  Since I am their mom, and not their teacher, the kids expected me to just give them the answer.  I didn’t cave in.  I let them experiment for a few minutes.  Once they got a little frustrated, I reminded them to think of how our Snap Circuits work.  Everything must be connected or nothing will happen.

When that hint wasn’t enough, I told them to think of the word circuit.  The beginning of the word sounds a lot like the beginning of the word circle.  I prompted them to think of a circuit in the shape of a circle, plus use the other hint that everything must be connected.

In another minute or two, both kids got the lightbulb to glow.  Their smiles were wide and proud.  They had done it all on their own.

In kid-friendly language, I explained how this circuit worked.  I needed to use kid-friendly  language because my understanding of electricity is not much more advanced than a fourth grade level!  Here is how I explained it to them:

When the battery, bulb, and wire are connected, energy leaves the negative end of the battery, travels through the wire, hits the metal part of the light bulb and finds the support wire.  It then goes into the light bulb by traveling up the support wire, crosses the filament, which gets so hot that it glows.  The energy doesn’t stop just because the light is on.  It continues to move down the other support wire, out of the bottom of the light bulb and back into the positive end of the battery.

033 (1)I drew a crude diagram to explain how this works.  We also took apart one of the light bulbs, so that the children could see how one support wire leads to the screw part of the bulb, and the other support wire leads to the very bottom.  That is why the bulb needs to be touched on the side and the bottom.  I also explained that electricity only travels through certain materials.  That is why the support wires and filament are metal. It’s also why we cover the wire in plastic – so we don’t get shocked.

We experimented with putting the light bulb on the other end of the battery, to see if it would work.  (It does.)  Then I left the materials out for the kids to play with whenever they want.  (Often!)

This is such a fun introduction to electricity.  Luke and Leah really learned a lot from this little experiment.  If you want to try it, you can find detailed directions here.  Some other things you could explore are why parts of the circuit feel warm to the touch.  (Escaping energy.)  You could also try bigger bulbs or different batteries to see if the circuit will still work.  I know we’ll be moving on to more complex tasks, such as building a series circuit and parallel circuit soon!

If you enjoyed this article, you’ll also like:

Experience #1:  Starting 2012 With a Shock

New Experience #51: Ivory Soap Experiment


About 52BrandNew

I am a single stay at home mom who is determined to live life to its fullest.
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