# The magnetic field of earth at the equator is approximately $\; 4 \times 10^{-5} \;T\;$ The radius of earth is $\;6.4 \times 10^{6}\;m\;$.Then the dipole moment of the earth will be nearly of the order of :

$(a)\;10^{23}\;Am^{2} \qquad(b)\;10^{20}\;Am^{2}\qquad(c)\;10^{16}\;Am^{2}\qquad(d)\;10^{10}\;Am^{2}$