The coil in Figure has 250 turns and is wound on a silicon sheet steel. The inner and outer radii are 20 and 25 cm, respectively, and the toroidal core has a circular cross section. For a coil current of 2.5 A. Find (a) The magnetic flux density at the mean radius of the toroid. (b) The inductance of the coil, assuming that the flux density within the core is uniform and equal to that at the mean radius. N