Chapter 30, Problem 15P

GO A square wire loop with 2.00 m sides is perpendicular to a uniform magnetic field, with half the area of the loop in the field as shown in Fig. 30-43. The loop contains an ideal battery with emf ℰ = 20.0 V. If the magnitude of the field varies with time according to B = 0.0420 − 0.870t, with B in teslas and t in seconds, what are (a) the net emf in the circuit and (b) the direction of the (net) current around the loop?

Figure 30-43 Problem 15.