# Find magnitude of current to produce magnetic field

## Homework Statement

Suppose that the magnetic field of the Earth were due to a single current moving in a circle of radius 1758 km through the Earth's molten core. The strength of the Earth's magnetic field on the surface near a magnetic pole is about 6. 10^-5 T. About how large a current would be required to produce such a field?

## Homework Equations

B=(μ0/4∏)∫I*dl X r^ / r^2