Problem

A wire near the equator carries a current perpendicular to the Earth’s magnetic field of 50μT in a location where the field is parallel to the ground and points straight north. The wire has a mass per length of 5.9g/m. What magnitude of current in the wire could balance it against the force of gravity? (This example is not very realistic. The mass per length given would be reasonable for a very thin wire which could not handle this large of a current for very long.)