Q: The magnetic moment of magnet of mass 75 gm is 9 × 10^{-7} A-m^{2} . If the density of the material of magnet is 7.5 × 10^{3} kg m^{-3} , then find intensity of magnetisation .

Sol: I = M/V Where Volume, V = (mass(m))/(density(p))

$\large I = \frac{M \times \rho}{m} $

$\large I = \frac{9 \times 10^{-7} \times 7.5 \times 10^3}{75 \times 10^{-3}} $

= 0.09 A/m.