Experiments with Magnets
- You can reveal the field of magnetism around a bar magnet with a few household objects. You'll need iron filings in a salt shaker type of dispenser (if iron fillings are unavailable, use scissors to cut up a steel wool pad finely), a sheet of white paper, thin piece of cardboard and a bar magnet.
Tape the white paper to the cardboard and place the cardboard over the bar magnet. Next, sprinkle the iron filings onto the paper, and then gently tap the cardboard. Once the cardboard has been tapped the iron filings will move align themselves and reveal the shape of the bar magnet. You should also notice a cluster of iron filings around the ends of the bar magnet where the filings surround the poles. - Temporary magnets are something that exhibits magnetic qualities when around a magnetic field. For instance, paperclips and nails are not normally magnetic in and of themselves, however when exposed to or stimulated by a strong magnet, the paperclip or nail will attract or repel other magnets.
Hold a steel magnet against a piece of wood with one hand and use the other hand to stroke the length of the nail with a bar magnet. Be sure to stroke only in one direction with the same pole of the magnet each time. After about 30 strokes, check the nail's magnetism. This is considered a temporary magnet. - Un-magnetized objects have their atoms aligned in a random fashion, whereas magnetized objects have atoms aligned with the north pole facing one direction and the south pole facing the opposite direction.
Demagnetize an object by dropping it several times on a non-magnetic object, such as the floor. The first drop might not fully demagnetize the object, however the strength will lessen. Test how many times it takes to fully demagnetize a magnetized nail. - Create a simple compass with a few household objects. You'll need a sewing needle, the bottom of a Styrofoam cup and a bowl of water. Place the Styrofoam cup on top of the bowl of water and then place the needle inside the foam disc. The needle should behave like a compass, always pointing in the same direction regardless of how you twist or move the bowl of water.
- Ever wondered whether magnetism is affected by temperature? The properties of magnets are altered when exposed to three levels of temperatures: 0 degrees Celcius, 100 degrees and minus 196 degrees (see Resources).
