|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".
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