Why Does an Aluminum Ring Levitate Above a Magnetic Coil?

AI Thread Summary
An aluminum ring levitates above a magnetic coil due to the interaction between the alternating current in the coil and the ring's electrons. The changing magnetic field creates an electromotive force (emf) in the ring, according to Faraday's Law, which induces currents within the aluminum. Although aluminum is non-magnetic, these induced currents generate a magnetic field that interacts with the coil's field, resulting in a Lorentz force that propels the ring upward. The strength of the induced emf is sufficient to overcome gravitational forces, causing the ring to rise. Understanding this phenomenon involves examining the principles of electromagnetic induction and the behavior of induced currents.
cheez
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A magnetic coil connected to AC power and an aluminum ring. The ring was placed on top of the coil and, although aluminum is non magnetic, the ring was thrown to the ceiling. Explain 1, why was there any force on the ring? 2. Why the ring went up? Use diagram and Faraday's Law

I don't know how to answer these questions. :(
I know the alternating current makes the magnetic field changes. And the changing magnetic field generates emf.But I don't know why the emf is large enough to push the aluminum ring upward, and how come it goes up?

thx a lot.
 
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A few more details might help but I would examine the Lorentz force acting on the electrons that were set in motion by the induced EMF.
 

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