Testing Magnetic Field Range with Paperclips
Make a holder for a bar magnet. You can make a simple magnet holder using a clothespin and a paper or Styrofoam cup. This method would be suitable for teaching elementary school-age students about magnetic fields.
Tape one of the long ends of a clothespin to the bottom of the cup.
Place the cup with the attached clothespin on the table upside down.
Insert the magnet into the clothespin.
Bend a paperclip into a hook. The easiest way to do this is to pull out the outer end of the paperclip. You will need to be able to hang more paperclips from the hook.
Add further paperclips to measure the strength of the magnet. Touch the bent paperclip to the magnet at one of its poles. The hook portion should hang free. Hang paperclips from the hook. Keep doing this until the weight of the clips causes the hook to fall.
Note the number of paperclips that caused the hook to fall off. When you have added a sufficient number of paperclips and the hook falls off the magnet, carefully write down the exact number of paperclips that caused this to happen.
Add masking tape to the magnet pole. Put 3 small strips of masking tape over the magnet’s pole and hang the hook from it again.
Add paperclips to the hook until it falls off the magnet. Repeat the previous method of hanging paperclips from the original paperclip hook, until it eventually falls off the magnet.
Write down how many clips it took to make the hook fall this time. Make sure you note both the number of masking tape strips and the number of paperclips used.
Repeat the previous steps several times with more strips of masking tape. Each time, note the number of paperclips it took to make the hook fall off the magnet. You should notice that as you added strips, it took fewer and fewer clips to make the hook fall off.