Getting electricity to do something: simple circuits
Electricity has a current. Unfortunately, you can't see what is flowing.
However, if we imagine that there
is an "electrical fluid" that moves through wires (instead of tubes), we can
develop a conceptual language that will let us understand how electricity works.
Let's familiarize ourselves with some electrical components:
A D-cell battery has two ends (and sides, which don't do anything). A
battery is like a pump: it tries to push "the electrical fluid" out one end.
By convention, the direction of flow is from the positive end (the top of the battery
-- the end with the bump on it)
to the negative end (the bottom).
Many electrical components, like the motor in your kit, come with two wires
already attached. One lets the current get to the device, and the
other carries it away again.
When we connect the two wires to the two ends of the battery, something
is likely to happen.
Some electrical components, like the light bulb in your kit, have no labels at
all, and it isn't even clear where wires are supposed to be attached to it to
make it go. We will figure this out shortly.
Time to explore!
Here are some things to think about and do.
Do these activities. Record in
your journal about what you learned, and any questions or problems you
encountered. We will ask to see your journals at the end of the workshop.
Make the motor run.
Figure out how to use the battery holder and the wires with the
"alligator clips" on them to have the motor run by itself.
Light the light bulb!
The light bulb contains a very thin (the filament) that gets really hot when
the current runs through it. For this to happen, there needs to
be a way for the current to get from one end of the battery to one
end of the filament, and a way for the current to continue from
the other end of the filament to the other end of the battery.
But where are the places to connect to the two ends of the little
wire? That's for you to figure out.
Need a hint?
Make a drawing showing a "cut away" view
of the inside of a light bulb, that shows how it might be connected together.
Do these activities. Record in
your journal about what you learned, and any questions or problems you
encountered. We will ask to see your journals at the end of the workshop.