The earth's magnetic field lines resemble that of a dipole at the centre of the earth. If the magnetic moment of this dipole is close to 8×1022 Am2 , the value of earth's magnetic field near the equator is close to (radius of the earth = 6.4×106 m )
a. 0.6 Gauss
b. 1.2 Gauss
c. 1.8 Gauss
d. 0.32 Gauss