A domain in ferromagnetic iron is in the form of a cube of side length 1µm. The maximum possible dipole moment is:

[The molecular mass of iron is 55 g/mole and its density is 7.9 g/cm³. Assume that each iron atom has a dipole moment of 9.27×10^–24 A $m^2]$ 

^{$$\begin{gathered} 1. 8.0\times {10}^{-13} A m^2 \\ 2. 8.0\times {10}^{-12} A m^2 \\ 3. 7.0\times {10}^{-13} A m^2 \\ 4. 7.0\times {10}^{-12} A m^2 \end{gathered}$$}

A domain in ferromagnetic iron is in the form of a cube of side length 1µm. The magnetisation of the domain is:

[The molecular mass of iron is 55 g/mole and its density is 7.9 g/cm³. Assume that each iron atom has a dipole moment of 9.27×10^–24 A $m^2]$ 

^{$$\begin{gathered} 1. 9.0\times {10}^5 A{m}^{-1} \\ 2. 8.0\times {10}^5 A{m}^{-1} \\ 3. 11\times {10}^5 A{m}^{-1} \\ 4. 3.0\times {10}^5 A{m}^{-1} \end{gathered}$$}