Figure a show two concentric circular regions in which uniform magnetic fields can change. Region 1, with radius r1 = 1.0 cm, has an outward magnetic field B1, that is increasing in magnitude. Region 2, with radius r2 = 2.0 cm, has an outward magnetic field B2, that may also be changing. Imagine that a conducting ring of radius R is centered on the two regions and then the emf ? around the ring is determined. Figure b gives emf ?, as a function of the square R2 of the ring's radius, to the outer edge of region 2. The vertical axis scale is set by ? s = 20.0nV. What are the rates?(a) dB1/dt and(b) dB2/dt?(c) Is the magnitude of B2 increasing, decreasing, or remaining constant?

(a) E, R* (cm) (b) 2. (Au) 3