Question

The magnetic susceptibility is negative for___?

• A. Diamagnetic material only
• B. Paramagnetic material
• C. Ferromagnetic material
• D. Paramagnetic and ferromagnetic material

Answer 1

The correct option is A

Diamagnetic material only

Explanation for correct option:

A. Diamagnetic material only

Magnetic susceptibility

• Magnetic susceptibility determines the degree of magnetization of a material with respect to the applied magnetic field. It can be expressed as the ratio of magnetization to the intensity of the magnetic field.
• Diamagnetic materials freely magnetize in the magnetic field. However, the magnetization is in the direction opposite to that of the magnetic field. Materials like copper, and zinc develop feeble magnetization in opposite directions in the magnetic field. They are repelled by magnets and hence move from the stronger to the weaker part of the magnetic field.
• Paramagnetic and ferromagnetic materials show attraction towards the magnetic field. Examples of paramagnetic materials are magnesium, molybdenum, lithium, and tantalum. Ferromagnetic materials are able to retain their magnetic properties after the external field has been removed. Examples of ferromagnetic materials include Nickel, Cobalt, etc.

Diamagnetic materials have small and negative magnetic susceptibility, as they develop feeble magnetization in opposite direction in the magnetic field.

Explanation for Incorrect options:

(B) Paramagnetic substances develop feeble magnetization in the same direction as a magnetic field. These materials have positive magnetic susceptibility.

(C) Ferromagnetic substances are strongly attracted by the magnetic field and hence move from weak to strong regions. They have positive magnetic susceptibility.

(D) Both paramagnetic and ferromagnetic materials have positive magnetic susceptibility.

Hence, the correct option is A i.e. diamagnetic materials, magnetic susceptibility is negative