For ferromagnetic material, the relative permeability $\left({\mathrm{\mu }}_{\mathrm{r}}\right)$ versus magnetic intensity (H) has which of the following shape?

${\mathrm{\mu }}_{\mathrm{r}}=1+\frac{\mathrm{I}}{\mathrm{H}}$; as we know I is dependent on H, initialiy value of $\frac{\mathrm{I}}{\mathrm{H}}$ is smaller so value of ${\mathrm{\mu }}_{\mathrm{r}}$ increases with H but slowly but with further increases of H value of $\frac{\mathrm{I}}{\mathrm{H}}$ also increases i.e.,${\mathrm{\mu }}_{\mathrm{r}}$ increases rapidly. When material is fully magnerised l becomes constant. then with the increase of H ($\frac{\mathrm{I}}{\mathrm{H}}$decreases) ${\mathrm{\mu }}_{\mathrm{r}}$ decreases.