|MadSci Network: Physics|
The Faraday disc will generate an output with either the magnet stationary or rotating with the conductive disc. It is said that with the magnet stationary, application of DC power to the disc will cause a motor action to rotate the disc, but with the magnet attached to the disc, it will not act as a motor. It is also said that holding the disc still and rotating the magnet will not cause voltage to be generated in the disc. Question: Does the current in the disc (acting either as generator or motor) react against the mechanical magnet or against the magnetic field? If against the magnetic field, how is this reaction force "absorbed"? Does the answer to the above explain how attaching the magnet to the rotating disc prevent motor action but not generator action? To generate equal amounts of output power with and without the magnet attached to the disc, is equal mechanical input power required? An aside, but relevant: Why do physics books always discuss the force on a charged particle moving in a magnetic field, but never, that I have seen, the force of a charged moving particle on the field? Is there a force on the field (invoking Newton's laws dosen't "explain" a YES answer) Thanks
Re: How do you resolve the Faraday Disc paradox?
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