A magnetizing field of $5000 \mathrm{~A} / \mathrm{m}$ produces a magnetic flux of $4 \times 10^{-5} \mathrm{~Wb}$ in an iron rod of cross-sectional area $0.4 \mathrm{~cm}^2$. The permeabilit of the rod in Wb/A-m, is

The magnetization of bar magnet of length 5 cm , cross sectional area $2 \mathrm{~cm}^2$ and net magnetic moment $1 \mathrm{Am}^2$ is

Magnetic susceptibility of a paramagnetic substance is