Waiting for the food to come?
Hear an audio activity
contact and comments
Find out the latest Science News
kudos and connections
About do science
Do Science services
The Do Science store

To get a Do Science logo product, click here.

Send a t-shirt with an activity on the back
(Condiment Diver activity is on back).

Return to
The Archive List

Do you have a comment or response to this activity, submit it to the Do Science bulletin board.

More science activities can be found here:
while you're waiting for the food to come
Great for Science Fair projects!

While You're Waiting for the Food to Come
by Eric Muller, Illustrated by Eldon Doty


To order or find out more about this book,
click on the book cover above or on either cover version.
Go to the Do Science Store


See how AC current shakes with a magnet.


- A strong magnet.
If you have one, a nice big refrigerator magnet will work...or...Most hardware stores carry ceramic magnets that you can buy for a buck or two.

-A light bulb.
A bulb that has the filament (the wire that glows) closer to the glass walls works best. Elongated bulbs like decorative bulbs or ones that are used in appliances work well.

The Recipe:
While the bulb is turned on, hold the magnet next to the bulb. Watch what happens to the filament.

Food for Thought:
You should have seen the filament inside the bulb shake and wiggle?
Electricity from your wall socket alternates direction which's why the electricity in your house is called alternating current or AC. Electricity flows one direction then switches and flows the opposite way. This switching back and forth happens 120 times a second or goes through 60 cycles each second (a cycle is one episode of back and forth electrical flow).

A wire carrying electricity creates a magnetic field. If the direction of the electricity changes so does the magnetic field. The wire or filament inside the bulb does this. The hot glowing wire creates an alternating magnetic field.

Two magnets held near each other attract or repel each other. By holding your magnet near the bulb the filament inside the bulb gets attracted and repelled by the magnet 120 times a second. This causes the filament to wiggle and you can see this!

If you have access to an overhead projector, place the bulb on it with the projector turned off. You can see the shaking filament projected onto a screen.
(This option was passed along to us after seeing presenter extraordinaire, Al Gunther at NSTA Orlando.)


Copyright 1999 Do Science

Activities | Waiting for Some Food? | Hear an Audio Activity | Contact & Comments | Do News | Kudos & Connections
About Do Science | Educational Resources & Presentation Services | The Do Science Store
Search | Home

Copyright Do Science® 1999