6.8 The transformer shown in Fig. P6.8 consists of a longwire coincident with the z axis carrying a current I = Io cos wt,coupling magnetic energy to a toroidal coil

situated in the x-yplane and centered at the origin. The toroidal core uses ironmaterial with relative permeability µ, around which 100 turnsof a tightly wound coil serves to induce a voltage Vemf- asshown in the figure. (a) Develop an expression for Vemf. (b) Calculate Vemf for f = 60 Hz, µ = 4000, a= 5 cm,b=6 cm, c=2 cm, and Io = 50 A.