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Homework Help: How a current passes through a wire?

  1. Aug 12, 2009 #1
    1. The problem statement, all variables and given/known data
    I am a high school student of Taiwan. I'm investigating the parameters that determine the angular velocity of the strong magnet(RbFeB magnet) of the homopolar motor now.
    like this→

    And what beset me is that I don't know how a current passes through a strong magnet.
    I know that the surface of a RbFeB magnet is electroplated with a layer of conductive and metal material.
    I wonder if the current passes "through" the magnet or passes along the surface of the magnet. (I don't know how to prove it.)

    Thanks for your help!!!!!!!!!!!

    2. Relevant equations

    3. The attempt at a solution
    Last edited by a moderator: Sep 25, 2014
  2. jcsd
  3. Aug 12, 2009 #2


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    I don't know if RbFeB (without the electroplating) is a conductor or insulator. If it is a conductor, the current passes through the magnet. If it is an insulator, the current passes along the surface. The way to "prove" it is (a) look up the electrical properties of RbFeB or (b) get a sample that is not electroplated and measure its resistance.
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