A device called a flip coil can be used to measure the earth's magnetic field. The coil has 180 turns and an area of 1.5×10−2 m2. It is oriented with its plane perpendicular to the earth's magnetic field, then flipped 180 degrees so the field goes through the coil in the opposite direction. The earth's magnetic field is 8.0×10−2 mT , and the coil flips over in 0.20 s .

What is the average value of the emf induced in the coil during the time it is flipping?
(a) 0.54 mV
(b) 1.1 mV
(c) 2.2 mV
(d) 11 mV