The figure shows a coil with a sheet iron core with unlimited magnetic penetration and a rectangular cross-section. The coil is made of insulated copper wire with specific resistance p. Coil coefficient (le the ratio of the net cross-sectional area of copper to the total cross-sectional area of the coil) is equal to fw. A) Find the mean length (I) of both windings. B) If the flux density of the core is B, determine the electrical power input to the coil in terms of fw, I, Ho, p, B and the dimensions given in the figure. C) Find the energy stored in the magnetic field in terms of B and the dimensions of the shape. D) Using the results of parts (b) and (c), the electric time constant of the coil (r = L/R) Set. h=.Core thickness Coil cross section