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Energy lost in magnetism

  1. Mar 15, 2010 #1
    Two magnet I put nearer to each other in such a way that there is a repulsive force between them. Both the magnets have some potential energy with respect to each other. I keep magnet in this position for a long time & so magnetic field became weaker & so magnet have less amount of potential energy w.r.t. each other. So, where does the energy gone? For which work it is consumed?
  2. jcsd
  3. Mar 15, 2010 #2
    Why would the magnetic field get weaker?
  4. Mar 15, 2010 #3
    if the number of magnetic Domain go larger magnetic field will get weaker.
  5. Mar 17, 2010 #4
    Hello pallidin,
    If two magnet put in such a manner there is repulsion is acted between them, then lines of magnetic force of both magnet is in opposite direction, this leads lost in magnetism. That's why magnetism became weaker.
    I have heard this thing before if anything is wrong in this concept please tell me. I am from mechanical background so may be electrical misconception is there.
  6. Mar 17, 2010 #5
    So, is this saying that duct taping(or epoxy) two magnets together with N/N or S/S for a couple days, a week or a year will cause the two magnets to lose or reduce their magnetism?
  7. Mar 17, 2010 #6
    If you mean to ask why magnets become weaker after a long exposure, it's usually due to thermal losses.
    If you mean to ask about induced magnetism, consider the situation where the first magnet is small & the other is very strong. Even if the magnetic domains of the first magnet are to 'flip' over adiabatically, no energy is lost. It's just the energy density between the neighbouring poles of the magnets that decreases.
  8. Mar 17, 2010 #7
    Yes, the same thing which I want to tell you.
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