How large a current would a very long, straight wire have to carry so that the magnetic field 2.20 cm from the wire is equal to 1.00 g (comparable to the earth's northward-pointing magnetic field)?
Biot-Savart Law - Magnetic field around a straight conductor carrying a current I.
B = μ_0 I/2πr
where: B is strength of magnetic field in T. μ_0 is permeability of free space = 1.25664 x 10^ -6 T-m/A. I is current in A. r is distance from conductor in m.
