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Forces of magnetism

  1. Feb 12, 2015 #1

    I want to calculate the force exerted between two electromagnets, based on their current

    I want to hold two metallic discs together, how much force can I exert between them with electromagnetism?

    is this something simple?

    any hint?

  2. jcsd
  3. Feb 12, 2015 #2


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    Those calculations are complicated, and the result will depend on many details of the setup.
  4. Feb 12, 2015 #3
    can you give me an example at least?
    for example electrical current 1kAmpere is required to exert a force of 1kNewton
    isn't there an online calculator, simulator to play with?
    Last edited: Feb 12, 2015
  5. Feb 12, 2015 #4


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    If it would be that easy it would not be complicated. You'll need a detailed 3D model of your setup, various material constants, probably numerical simulations in two or three dimensions and so on.
    There is no way to even make a rough approximation without knowing how your setup looks like, and that's not something you can feed into an online tool in general.

    It can be easier to just measure it.
  6. Feb 13, 2015 #5


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    Build a small model, take measurements, then scale it up. If it will involve large currents for long durations, then heating of the electromagnet is going to be a major factor.

    An alternative might be to use powerful permanent magnets to hold things together long term, with an electromagnet to briefly oppose the field of the Neodymium Magnets so the discs can be swapped in/out. Try to avoid mechanically jarring permanent magnets, that can eventually weaken them, I believe. It might be feasible to slowly power down the electromagnet so that it cushions any slamming together of the neodymiums. :)

    Is this along the lines of a thought experiment, or do you have a real-world problem to solve?
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