A steel ring has a mean diameter of 20 cm and a cross-section of 25 cm and a radial air gap 0.8 mm cut across it. When excited by a current of 1 A through a coil of 1000 turns wound on the ring core, it produces an air gap flux of I mWb. Calculate; (i) the total reluctance of the magnetic circuit. (ii) the relative permeability of steel. 3. A magnetic circuit with a 1200 turns windings wrapped around the center leg of the core is shown in figure below. Given the relative permeability of the core steel is 3000 and the permeability of the free space, u, is 47x 107 Wh/Am. Assume the coil resistance is zero and no flux leakage. (i) Sketch the equivalent analogous electrical circuit of the magnetic circuit. (ii) (iii) Calculate the total flux in the core, given the exciting current of the coil equals to I A. Calculate the total reluctance of the core. 2.