1000 turns per meter are wound over a Rowland ring of ferromagnetic material. On passing a current of 2 ampere in the coil, a magnetic field of 10 Wb/m2 is produced in it.

The value of intensity of magnetisation in A/m will be :

7.96 x 10⁶

$ B = \mu_0(I+H)$

$ I = \frac{B}{\mu_0} - H$

$ I = \frac{10}{4\pi \times 10^{-7}} - 2\times 10^3 = 7.96\times 10^6A/m$