The transformer shown in the figure consists of a long wire coincident with the z current I=1, cos(wt), coupling magnetic energy to a toroidal coil situated in the x - y plane and centered at the origin. The toroidal core uses iron material with relative permeability μr, around which 100 turns of a tightly wound coil serves to induce a voltage Vemf, as shown in the figure. a. Develop an expression for Vemf b. Calculate Vemf for f = 60 Hz, μr = 4000, a = 5 cm, b = 6 cm, c = 2 cm, and I₁ = 50 A. Vemf - axis carrying a Iron core with p x