In this example, we will use B=₀I/2r to calculate the distance from a wire that is associated with a particular magnetic field. Specifically, a long, straight wire carries a current of 100 A. At what distance from the wire is the magnitude of the magnetic field from the current equal to the magnitude of earth's magnetic field, which is about 5.010⁵T?

1. At what distance from a wire carrying a current of 110 A would the wire make a magnetic field with the same magnitude as the earth's?