An object is considered to be magnetic, or magnetically charged when the electron particles of an object all point in the same direction. Magnets have two sides or poles, the north pole is positively charged and the south pole is negatively charged. Magnets are attracted to each other when opposite poles are near each other; magnets are repelled when similar poles are near each other.
Types of Magnets
There are two types of magnets: permanent magnets and temporary magnets.
Permanent magnets are made of things that are permanently magnetic; meaning that their electrons will not change directions.
Temporary Magnets only exhibit signs of magnetism when exposed to strong magnet fields. When temporary magnets are exposed to permanent magnets their atomic composition adjusts so that the poles point in the same direction; they then take on magnetic properties and will become either attracted or repelled by other magnets.
Types of Temporary Magnets
Temporary magnets are made from soft metals, and only retain their magnetism while near a permanent magnetic field or electronic current. Common temporary magnets include nails and paperclips, which can be picked up or moved by a strong magnet.
Another type of temporary magnet is an electromagnet which only retains magnetism when an electrical current is running through it. Electromagnets vary in strength and polarity, and are composed of coil wire usually with an iron core. Electromagnets are used in common objects such as doorbells and complex objects such as motors.
How to Make a Temporary Magnet
Magnets are created when the electrons in the object all point in the same direction. Common ways to create a temporary magnet include bringing the object close to a magnet, striking the object while in a magnetic field, and stroking the object on a magnet. A temporary magnet can also be created by using an electrical field.
How to Demagnetize a Temporary Magnet
Magnets are created when all the atoms in the object are aligned with the north pole in one direction and the south pole in another direction. When the atoms are jarred, such as being dropped on the floor, the object will return to its normal non-magnetic state.
Science Fair Projet Ideas
Students looking for an interesting science experiment on temporary magnets should consider learning about how temperature affects magnetism. The “Hot on Magnets” experiment gives suggestions on heating and cooling magnets, and how to measure their strength. Consider adding to the experiment by comparing permanent magnet strength to temporary magnet strength.
- Cool Magnet Man
- Electricity and Magnetism Science Fair Projects; Robert Gardner; 2004.
- Decorative magnets of Prague image by TekinT from Fotolia.com