Question

The magnetic dipole moment of Earth is 8.00 ✕ 1022 J/T. Assume that this is produced by charges flowing in Earth's molten outer core. If the radius of their circular path is 3350 km, calculate the current they produce.

Answer 1

To solve the problem it is necessary to use the concepts and expressions related to the magnetic dipole moment.

It is usually defined by,

$\mu = IA$

Where,

$\mu =$ Magnetic Dipole Moment

I = Current

A = Area

In this way re-arrange for the current and replacing,

$I = \frac{\mu}{A}$

$I = \frac{8*10^{22}}{\pi R^2}$

$I = \frac{8*10^{22}}{\pi * (3350*10^3)^2}$

$I = 7.1285*10^9A$

Therefore the current is $7.1285*10^9$  Amperes