You want to get an idea of the magnitude of magnetic fields produced by overhead power lines. You estimate that a transmission wire is about 11 m above the ground. The local power company tells you that the line operates a 11 kV and provide a maximum of 48 MW to the local area. Estimate the maximum magnetic field you might experience walking under such a power line, and compare to the Earth's field. [For an ac current, values are rms, and the magnetic field will be changing. Let the Earth's magnetic field strength be 5.0 10-5 T.]