You want to get an idea of the magnitude of magnetic fields produced by overhead powerlines. you estimate the that a transmission wire is about 11m above the ground. the local power company tells you that the lines operate at 240 kv and and provide a maximum power of 46 mw.
a. estimate the magnetic field you might experience walking under one such power line.
b. compare this field to the earth's field: bwire/bearth= ? %