I have an aluminum desktop toy that is not magnetic but when I spin it and move some high strength neodymium magnets near it slows down a lot faster than normal. Is this forming some kind of eddy current in the metal creating some form of drag? Or is there some other contributing factor that I am overlooking? And if I am right how exactly is it creating this drag effect?
2 Answers
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The drag is due to repulsion caused by eddy currents induced by the moving magnetic field in the Aluminum metal.
The repulsive force opposes the motion of the metal ball according to Faraday's second law of electromagnetism.
The same thing will happen if you replace the aluminum with copper metal.
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$\begingroup$ Some more videos: youtu.be/VEIYXomRdLY, and youtu.be/sENgdSF8ppA. $\endgroup$– PhilipCommented Apr 10, 2021 at 11:37
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$\begingroup$ @Philip Erm... this 'NightHawkInLight' is dropping the ball at every turn. It so happens the video I linked to has no voice-over. That is for the best, it seems. $\endgroup$– CleonisCommented Apr 10, 2021 at 11:49