Chapter 23, Problem 25PCE

Predict/Explain (a) As the solid metal disk in Figure 23-37 swings to the right, from the region with no field into the region with a finite magnetic field, is the induced current in the disk clockwise, counterclockwise, or zero? (b) Choose the best explanation from among the following:

1. I.                    The induced current is clockwise, since this produces a field within the disk in the same direction as the magnetic field that produced the current.
2. II.                 The induced current is counterclockwise to generate a field within the disk that points out of the page.
3. III.              The induced current is zero because the disk enters a region where the magnetic field is uniform.