- #1
Gusbob
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Problem Statement
In a recent exam, I was asked the following question:
"A superconducting disc is suspended on strings (horizontally, flat side facing ground) and cooled below it's critical temperature. A bar magnet is placed on a spinning axle under the disc. What happens to the disc once the magnets begin to spin?"
Attempt at Solution
What the answer key indicated was that the disc will spin in the same direction as the magnet because a current will be induced due to Lenz's law. However, my teacher said that explanation does not take into account of the meissner effect, and that the disc will not spin at all because the magnetic field is expelled. Can someone clear this up for me?
In a recent exam, I was asked the following question:
"A superconducting disc is suspended on strings (horizontally, flat side facing ground) and cooled below it's critical temperature. A bar magnet is placed on a spinning axle under the disc. What happens to the disc once the magnets begin to spin?"
Attempt at Solution
What the answer key indicated was that the disc will spin in the same direction as the magnet because a current will be induced due to Lenz's law. However, my teacher said that explanation does not take into account of the meissner effect, and that the disc will not spin at all because the magnetic field is expelled. Can someone clear this up for me?