Question

A thin light weight rod of diamagnetic substance such as silver is suspended in a uniform external magnetic field. It will align itself with its length

• A. perpendicular to magnetic field.
• B. inclined at an angle 120° to magnetic field.
• C. inclined at an angle 45° to magnetic field.
• D. parallel to magnetic field.

Hint:

In diamagnetic materials, the induced magnetic moment opposes the applied magnetic field, leading to alignment perpendicular to the field.

Answer 1

The Correct Option is A

Step 1: Diamagnetic behavior.
Diamagnetic substances create an induced magnetic field in the direction opposite to the applied magnetic field. This causes a force that tends to align the substance in a direction where it minimizes energy.
Step 2: Orientation of the rod.
For a thin diamagnetic rod suspended in a uniform external magnetic field, it aligns itself perpendicular to the magnetic field. This minimizes the potential energy of the system, as the magnetic moment opposes the external field.
Step 3: Conclusion.
The rod will align itself perpendicular to the magnetic field, so the correct answer is (A).