A square wire loop with 1.87 m sides is perpendicular to a uniformmagnetic field, with half the area of the loop in the field asshown in the figure 30-44. The loop contains an ideal battery withemf ε = 20.0 V. If the magnitude of the field varies with timeaccording to B = 0.0510 - 0.782t, with Bin teslas and t in seconds, what is the net emf in the circuit?