Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Demagnetizing field

  1. May 29, 2009 #1
    Can anybody enlighten me on what demagnetizing field is and how it comes to existence?
  2. jcsd
  3. May 29, 2009 #2


    User Avatar
    Science Advisor

    At the end of a bar magnet, H points in the opposite direction to M and B. This is due to the boundary condition on H at the end of a magnet. In many books, this is called a
    "demagnetizing field". That is a misnomer, because it is B and not H that acts to polarize the atoms in the iron. Since B near the end of the magnet is 1/2 its value at the middle, there is some tendency for the magnet to lose a bit of its magnetization (M) over time.
  4. May 30, 2009 #3
    I'll try to absorb what you said, and then come back.
    Thanks for your post
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook