If the Earth's magnetic field at the equator is about `4 xx 10^(-5)T`, What is its approximate magnetic dipole moment ?

Explanation

Given, `B_(E) = 4 xx 10^(-5) T, r = 6.4 xx 10^(6)m, m = ?`
`B_(E) = (mu_(0))/(4pi)(m)/(r^(3))`
`4 xx 10^(-5) = (4pi xx 10^(-7))/(4pi) xx (m)/((6.4 xx 10^(6))^(3))`
`m = 4 xx 10^(2) xx (6.4 xx 10^(6))^(3)`
`:. m = 1.05 xx 10^(23) Am^(2) ~~ 1 xx 10^(23) Am^(2)`