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Electromagnetics question

  1. Dec 3, 2007 #1
    see this set-up for a DC Motor

    If the sides of the copper frame were the only copper in the field, the motor would still work correct? (stretch the copper frame out, or thin the magnets) So now we have only two sides of the copper frame in the magnetic field. Now if those sides rolled so that the same face of the copper was always facing the same magnet, would the motor still work?
  2. jcsd
  3. Dec 4, 2007 #2


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    What copper frame? What are you talking about?
  4. Dec 4, 2007 #3


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    Based on the fact that the frame cannot rotate (it's the frame and is supporting everything), there is no relative motion between the magnetic field and the conductor (frame in your example), no, it will not work.
  5. Dec 4, 2007 #4
    I mean the inducting copper in the picture, maybe "wire" is a better word for it.
  6. Dec 4, 2007 #5

    No. It would not. It's like asking if you jump up when you pull your boots on and then stand up before you touch the ground and jump up again, could you levitate upwards?
  7. Dec 4, 2007 #6


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    If I understand what you are asking correctly, then no, it won't work. If the wire was able to rotate somehow and face the same magnet, then motor would not provide any mechanical power since it is free to rotate such that it counters the torque developed by the current flow and flux interaction.
  8. Dec 4, 2007 #7
    Ok wanted to be sure about that, now here's another question, or theory.

    Could it be that on a quantum scale that it's a gyroscopic effect that is causeing the motor to work? A diamagnetic effect happens to the copper, but that effect happens as if B is an axis. So B causes a net "spin", or whatever, in one direction, on the atom, and when the metal is turned in this, it's like turning billions of little gyroscopes, and so current flows as the reactant force?
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