Materials suitable for permanent magnets must have which of the following properties?

Which of the following statements is correct for diamagnetic materials?

Which of the following statements are true about the magnetic susceptibility ${\chi _m}$ of a paramagnetic substance?

$A$ paramagnetic salt contains $2 \times 10^{26} \, m^{-3}$ atomic dipoles. Each dipole has a magnetic moment of $1.5 \times 10^{-23} \, A \cdot m^2$. What is the saturation magnetization?

Choose the $CORRECT$ variation of $\mu$ (permeability of material) with magnetising field intensity $(H)$ for a ferromagnetic material.

$A$ sample of paramagnetic salt contains $2.0 \times 10^{24}$ atomic dipoles each of dipole moment $1.5 \times 10^{-23} \; J \, T^{-1}$. The sample is placed under a homogeneous magnetic field of $0.64 \; T$ and cooled to a temperature of $4.2 \; K$. The degree of magnetic saturation achieved is $15 \%$. What is the total dipole moment of the sample for a magnetic field of $0.98 \; T$ and a temperature of $2.8 \; K$? (Assume Curie's law)