provides one model for solving this problem. The maximum strength of the earth's magnetic field is about 6.9 x 10-5 T near the s
outh magnetic pole. Suppose we want to utilize this field with a rotating coil to generate 84.5-Hz ac electricity What is the minimum number of turns (area per turn = 0.021 m2) that the coil must have to produce an rms voltage of 170 V?