According to Curie's law,the magnetic susceptibility of a substance at an absolute temperature $T$ is proportional to

Oersted is a unit of

$A$ magnetizing field of $100 \,A/m$ produces a magnetic flux of $2.4 \times 10^{-5} \,Wb$ in an iron bar of cross-sectional area $0.3 \,cm^2$. The magnetic permeability of the iron bar in the $SI$ unit is

An iron rod of cross-sectional area $2 \times 10^{-5} \ m^2$ is subjected to a magnetizing field intensity of $2000 \ A/m$. If the magnetic flux produced in the rod is $6.28 \times 10^{-4} \ Wb$,what is the magnetic permeability of the rod?

The magnetic susceptibility of the material of a rod is $599$. The absolute permeability of the material of the rod will be $\left[\mu_0=4 \pi \times 10^{-7} \text{ SI unit}\right]$.

Which of the following relations is incorrect?
$(a) \ B = \mu_0(H + I)$
$(b) \ B = \mu_0(H + \chi_m)$
$(c) \ \mu_r = 1 + \chi_m$
$(d) \ \chi_m = I / H$
(Here,$I =$ intensity of magnetization and $H =$ magnetising field)