The magnetic moment of the assumed dipole at the earth's centre is `8.0 xx 10^22 A m^2`. Calculate the magnetic field `B` at the geomagnetic poles of the earth. Radius of the earth is `6400 km`.

Explanation

The goomagnetic pole ia at the and on position of the earth
`B = (mu)(0))/(4 pi) (2M)/(d^(3))`
`= (10^(-7) xx 2 xx 8 xx 10^(22))/((64)^(3) xx 10^(13))`
`= 60 xx 10^(6)T = 60 mu T`