A long, straight, horizontal wire carries a left-to-right current of 20 A. If the wire is placed in a uniform magnetic field of magnitude T that is directed vertically downward, what is the resultant magnitude of the magnetic field 20 cm above the wire?
A typical current in a lightning bolt is A. Estimate the magnetic field 5.0 m from the bolt.
A transmission line strung 3.00 m above the ground carries a current of 335 A. What is the magnetic field on the ground directly below the wire?