Diamagnetic materials are repelled by magnetic fields.

• A. True
• B. False
• C. Not sure
• D. Not applicable

Answer: (A)

Diamagnetic behavior arises when an external magnetic field induces currents (or orbital motions of electrons) that create a magnetization opposite to the applied field. This opposite magnetization gives the material a negative magnetic susceptibility, so in a nonuniform magnetic field there is a net force that pushes the diamagnetic material away from stronger field regions. In other words, the material is repelled by the magnetic field. The effect is typically very weak, which is why everyday materials often seem unaffected, but it is observable in strong fields or with highly diamagnetic substances like copper, quartz, water, and especially bismuth. By contrast, materials with paramagnetic or ferromagnetic behavior have induced moments that align with the field and are attracted to magnets.