The permanent magnetic moment of the atoms of a material is not zero. What can you say about the material?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → It may be paramagnetic.
Option (1) It must be paramagnetic. — Incorrect. Atoms with a permanent magnetic moment are found in ferromagnetic materials too, so a non-zero atomic moment alone does not make the material paramagnetic.
Option (2) It must be diamagnetic. — Incorrect. In a diamagnetic substance, the resultant magnetic moment of each atom is zero. A moment appears only in an applied field, and it points opposite to that field.
Option (3) It must be ferromagnetic. — Incorrect. Ferromagnetism needs, besides the atomic moments, an interaction that aligns them spontaneously in domains. Paramagnetic atoms have permanent moments without such alignment.
Option (4) It may be paramagnetic. — Correct. The atoms of a paramagnetic material have a permanent magnetic dipole moment, and so do the atoms of a ferromagnetic material. The material is therefore paramagnetic or ferromagnetic, so it may be paramagnetic.
NCERT (2026-27):
Paramagnetism – “The individual atoms (or ions or molecules) of a paramagnetic material possess a permanent magnetic dipole moment of their own.”
Ferromagnetism – “The individual atoms (or ions or molecules) in a ferromagnetic material possess a dipole moment as in a paramagnetic material.”