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:
- AThe lattice structure of the material of the rod
- BThe magnetic field
- CThe current source
- DThe induced electric field due to the changing magnetic field
Solution & Step-by-step Explanation
Diamagnetic materials are repelled by magnetic fields (moving from stronger to weaker field regions). When the electromagnet is turned on, it creates a magnetic field. The work done in pushing the rod against gravity is provided by the energy of the current source that powers the electromagnet.