stepped up from 120 V to 1200 V and then down again rather than simply transmitting at 120 V. Assume the trans formers are each 99% efficient. 29-7 Changing Dy Produces E 54. (II) In a circular region, there is a uniform magnetic field B pointing into the page (Fig. 29-47). An xy coordinate system has its origin at the circular region's center. A free positive point charge +Q = 1.0/C is initially at rest at a position x = +10 cm on the x axis. If the magnitude of the magnetic field is now decreased at a rate of -0.10 T/s, what force (magnitude and direction) will act on +0? X X X xO -x X X= +X X X X FIGURE 29-47 X XI Problem 54. x ! General Problems 58. Suppose you are looking at two current loops in the plane of the page as shown in Fig. 29-49. When the switch S is closed in the left-hand coil, (a) what is the dir