| MadSci Network: Physics |
Sarah,
There are two issues that your question addresses. Can the power of
an individual magnet be changed, and do two (or more) separate magnets add
their power together?
I will assume that you are asking about permanent magnets, like bar
magnets or refrigerator magnets. Permanent magnets have internal domains,
which are regions of aligned magnetic dipoles. These dipoles are the atoms
of the magnet. When a permanent magnet is magnetized, what happens is that
one of the domains grows larger than any of the other domains. The power
of the magnet depends on how much of the magnet is part of this largest
domain, so there is an upper limit to the power of a single magnet, but it
can be varied below that.
Two separate magnets can combine their power to create a more powerful
magnet, but as you have probably noticed, combining two magnets to add
their power is not easy. The magnets will (usually) want to combine so
that the power is lower, but it is possible to hold them in some sort of
framework, so that the powers add in the way that you want.
I hope that this has answered your question. If you want to read more
about magnets, you should know that the word "power" has a very specific
meaning in physics, and we have used it incorrectly here. The quantity
that is used to describe the strength of magnets is called the "magnetic
moment" or sometimes "magnetic dipole".
Try the links in the MadSci Library for more information on Physics.