Magnetic Materials & Curie Law
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
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Answer: (a)
- A diamagnetic rod is pushed from a strong field region to a weaker one, so it gains potential energy.
- When the current is switched on, the changing flux induces an emf in the electromagnet coil. The source does extra work against this emf.
- That extra energy from the current source becomes the rod's gain in potential energy.
- So the answer is (a) the current source.