The universal property of all substances is

$A$ paramagnetic sample shows a net magnetization of $0.8 \text{ A m}^{-1}$ when placed in an external magnetic field of strength $0.8 \text{ T}$ at a temperature of $5 \text{ K}$. If the temperature is raised to $20 \text{ K}$, then the magnetization becomes: (in $\text{ A m}^{-1}$)

Magnetic susceptibility for a paramagnetic and diamagnetic material is respectively

The Curie temperatures of cobalt and iron are $1400 \,K$ and $1000 \,K$ respectively. At $T=1600 \,K$, the ratio of the magnetic susceptibility of cobalt to that of iron is

The materials suitable for making electromagnets should have

The magnetic susceptibility of ferromagnetic materials is