[whoosh] [ding] Hi, this is Ben Finio with Science Buddies and this video will show you
how to use your basic circuits kit to determine if materials are electrical conductors or
insulators.
So here we have all the parts in the kit, you have four double A batteries, you have
a three double A battery holder so your kit comes with one extra battery, you have a small
light bulb, a light bulb base, and three alligator clips which get their name because they have
these little metal jaws that can grab on to wires and circuit components.
To assemble your kit first you’re going to put three batteries in the battery holder.
Look closely at the batteries, you see that there are plus signs on one end of the batteries,
there are also plus signs printed inside the battery holder.
Make sure those plus signs line up.
You can also check the flat end of the battery is the side that goes up against the spring.
So put three batteries in the battery holder and then put the fourth battery aside.
Next just screw the light bulb into the base, and now you are ready to connect everything
with the alligator clips.
So we’re going to color code here, take the red alligator clip and connect it to the
red wire from the battery pack, take the black alligator clip and connect it to the black
wire, oops you can see so these alligator clips will hold on kind of snugly but if you
pull too hard they will come off, so I lost the red one there I’m going to reattach
that.
Now here’s one important safety note, at this point you want to make sure that the
red and black alligator clips do not touch each other directly.
That will create a short circuit and can cause your battery pack to get very hot.
So keep those nice and spaced out, away from each other on your table so they don’t bump
into each other.
Now you’re going to take your light bulb holder, and it has these two little screws
on it on either side that you can connect the alligator clips to.
Now it will be a little easier to connect to those if you actually take a small Philips
head screwdriver and loosen the screws slightly.
That kind of gets the surface up away from the bottom so it’s not flush there and it
will be easier to get them with the alligator clips.
So once you’ve loosened those a little bit, take the other end of the black alligator
clip, connect it to one of the screws, and now take the green alligator clip which you
haven’t used yet and connect it to the other screw.
So as of right now, we still have an open circuit.
There is no complete path for the electricity to flow so this light bulb does not light
up.
However if I take the free ends of the red and green alligator clips and touch them together,
I have a closed circuit so electricity can flow in a loop through this red wire, through
the green alligator clip, through the light bulb and then back through the black alligator
clip and wire to the battery pack.
So check that your light bulb lights up when you touch these two alligator clips together.
If it does not light up, make sure that all your connections are secure and you don’t
have a loose alligator clip and you did not put a battery in the battery pack backwards,
and once that’s working you are ready to start your experiment.
Now to test if a material is a conductor or an insulator, all you have to do is connect
it to the free ends of your red and green alligator clips.
I’m going to start out by testing this popsicle stick, so I take my two alligator clips and
pinch them onto the ends, and notice that the light bulb does not light up.
That means that this popsicle stick is an insulator, it does not allow electricity to
flow.
Now I’m going to remove my alligator clips and try with this quarter.
Again I’m going to connect to both sides of the quarter with the alligator clips, and
notice that now that the light bulb lights up.
This means that the quarter is a conductor and it does let electricity flow in a complete
circuit and through the light bulb.
You can try this with all sorts of other materials and objects you can find around your house
to classify whether they are conductors or insulators.
For directions for thousands of other science and engineering projects you can do for school
or at home, visit us online at www.sciencebuddies.org.