Although the evidence is weak, there has been concern in recent years over possible health effects from the magnetic fields generated by transmission lines. a typical high-voltage transmission line is 20 m off the ground and carries a current of 200 a . part a estimate the magnetic field strength on the ground underneath such a line. express your answer in microtesla. b b = nothing μt submitrequest answer part b what percentage of the earth’s magnetic field does this represent? (assume that magnetic field strength at the surface of the earth is 5× 10 −5 t ) express your answer in percent. b tl b earth b t l b e a r t h = nothing % submitrequest answer provide feedback next