An iron rod is placed parallel to magnetic field of intensity $$2000 \mathrm{~A} / \mathrm{m}$$. The magnetic flux through the rod is $$6 \times 10^{-4} \mathrm{~Wb}$$ and its cross-sectional area is $$3 \mathrm{~cm}^2$$. The magnetic permeability of the rod in $$\frac{\mathrm{Wb}}{\mathrm{A}-\mathrm{m}}$$ is