A light disc made of aluminum (a nonmagnetic material) is kept horizontally and is free to rotate about its axis as shown in the figure. A strong magnet is held vertically at a point above the disc away from its axis. On revolving the magnet about the axis of the disc, the disc will (figure is schematic and not drawn to scale)

rotate in the direction opposite to the direction of magnet's motion
rotate in the same direction as the direction of magnet's motion
not rotate and its temperature will remain unchanged
not rotate but its temperature will slowly rise
Solution:
When we start rotating the magnet above the disc, eddy currents will be generated in the disc. Now we know from Lenz's law that the induced emf will drive the current such that it opposes the cause of the production of induced emf. Hence the disc will rotate in the same direction as the direction of magnet's motion
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