The magnetic susceptibility of diamagnetic materials is
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → small and negative
A diamagnetic material develops a magnetisation opposite to the applied field, so \( \chi \lt 0 \). The effect is weak: \( \chi \) is typically about \( -10^{-5} \), so it is small and negative. (A superconductor, with \( \chi = -1 \), is the extreme case of perfect diamagnetism.)
Why the other options are incorrect
Option (1) small and positive — Incorrect. Small and positive describes paramagnetic materials.
Option (2) large and positive — Incorrect. Large and positive describes ferromagnetic materials.
Option (4) large and negative — Incorrect. Diamagnetism is always weak; \( \chi \) cannot be less than \( -1 \).
NCERT (2026-27):
Summary – …
