At Curie point,a ferromagnetic material becomes

Among the following, for which substance does the magnetic susceptibility not depend on the temperature?

$A$ substance is placed in a non-uniform magnetic field. It experiences a weak force towards the strong field. The substance is . . . . . . type.

If the magnetic dipole moment of an atom of diamagnetic material,paramagnetic material,and ferromagnetic material are denoted by $\mu_d, \mu_p, \mu_f$ respectively,then:

Pick out the $WRONG$ statements about magnetic substances ($\chi = \text{magnetic susceptibility}$, $\mu_r = \text{relative permeability}$).
$I$. Substances with $-1 \le \chi < 0$ are diamagnetic
$II$. Substances with $\chi \gg 1$ are paramagnetic
$III$. Substances with $\chi \ll 1$ are ferromagnetic
$IV$. Substances with $\mu_r \gg 1$ are ferromagnetic

Needles $N_{1}$,$N_{2}$,and $N_{3}$ are made of a ferromagnetic,a paramagnetic,and a diamagnetic substance,respectively. $A$ magnet when brought close to them will