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A thin diamagnetic rod is placed vertically between the poles of an electromagnet. When the current in the electromagnet is switched on, then the diamagnetic rod is pushed up, out of the horizontal magnetic field. Hence the rod gains gravitational potential energy. The work required to do this comes from

The lattice structure of the material of the rod
The magnetic field
The current source
The induced electric field due to the changing magnetic field
Explanation:

Energy of current source will be converted into potential energy of the rod.
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