Diamagnetic, Paramagnetic And Ferromagnetic Materials

Magnetic materials are classified by their magnetic susceptibility $\chi$, which relates the induced magnetization to the applied field through $M=\chi H$. Diamagnetic materials have no permanent atomic dipoles; an applied field induces moments opposing the field, giving a small negative $\chi$, so they are feebly repelled and tend to move toward weaker field regions. Paramagnetic materials have permanent but randomly oriented dipoles that partially align with the field, giving a small positive $\chi$ and feeble attraction. Ferromagnetic materials have strongly coupled domains producing a very large positive $\chi$ and strong attraction. The described material—feebly repelled with small negative susceptibility—is therefore diamagnetic. The paramagnetic option has the wrong sign of susceptibility. The ferromagnetic option describes far stronger attraction. The final option contradicts itself, since diamagnets cannot have large positive susceptibility. NCERT tabulates these three categories with their susceptibility ranges and temperature dependence. A consistency check: only diamagnetism gives negative $\chi$, uniquely fixing the answer. The three categories also differ in how they respond to temperature: paramagnetic susceptibility falls with rising temperature following Curie's law, while ferromagnets lose their strong magnetism entirely above the Curie temperature and become paramagnetic. Diamagnetism, arising from induced electronic currents that oppose the applied field by Lenz's law, is essentially temperature-independent and is present in all materials, though it is usually masked when stronger para- or ferromagnetic effects are present.