A solenoid having 400 turns per metre has a core of a material with relative permeability 400. When a current of 0.5 A is passed through it, the magnetization of the core material in $\mathrm{Am}^{-1}$ is nearly

The materials having negative magnetic susceptibility are

A bar magnet has length 4 cm , cross-sectional area $2 \mathrm{~cm}^2$ and magnetic moment $6 \mathrm{Am}^2$. The intensity of magnetisation of bar magnet is

In the following graph of flux density versus magnetizing force, coercivity and retentivity are respectively represented by the points