What does the magnetic susceptibility of a material show?

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 $........... \ Am^2$.

An iron rod of cross-sectional area $0.2 \, cm^2$ is subjected to a magnetizing field intensity of $1600 \, A \cdot m^{-1}$. If the magnetic flux produced in the rod is $2.4 \times 10^{-5} \, Wb$, what is the magnetic susceptibility of the material of the rod?

When a piece of a ferromagnetic substance is placed in a uniform magnetic field,the flux density inside it is four times the flux density away from the piece. The magnetic permeability of the material is

$A$ toroid has an average diameter of $2.5\,m$,$400$ turns,and a current of $2\,A$. If the total magnetic field inside the toroid is $10\,T$,what is the intensity of magnetization (in $A/m$)?

The permeability of a metal is $0.1256 \ TmA^{-1}$. Its relative permeability will be (Given: $\frac{\mu_0}{4 \pi} = 10^{-7} \ SI \ unit$,$\pi = 3.14$).