What does the magnetic susceptibility of a material show?

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

The relative permeability of iron is $2000$. Its absolute permeability in $SI$ units will be (given $\frac{\mu_0}{4 \pi} = 10^{-7} \text{ SI units}$):

An iron rod of susceptibility $599$ is subjected to a magnetising field of $1200 \, A m^{-1}$. The permeability of the material of the rod is $(\mu_{0} = 4 \pi \times 10^{-7} \, T m A^{-1})$.

If $M$ is the magnetisation induced in the material,$H$ is the magnetic field intensity,and $B$ is the net magnetic field inside the material,then the correct relation between them is $(\mu_0 = \text{permeability of free space})$

An iron rod of volume $10^{-3} \ m^3$ and relative permeability $1000$ is placed as a core in a solenoid with $10 \ turns/cm$. If a current of $0.5 \ A$ is passed through the solenoid,then the magnetic moment of the rod will be $........... \ Am^2$.