32-2 A toroidal solenoid has 500 turns, cross-sectional area 6.25 cm, and mean radius 4.00 cm. (a) Calcualte the coil's self- inductance. (b) If the current decreases uniformly from 5.00 A to 2.00 A in 3.00 ms, calculate the self-induced emf in the coil. (c) The current is directed from terminal a of the coil to terminal b. Is the direction of the induced emf from a to b or from b to a