TEL Q4 A wrought iron bar 30cm long and 2cm in diameter is bent into a circular shape as shown in figure below. It is then wound with 600 turns of wire. Calculate the current required to produce a flux of 0.5 mWb in the magnetic circuit in the following cases: i. ii. No air-gap With an air-gap of 1 mm; r (iron) = 4000 (assumed constant); and With an air-gap of 1 mm; assume the following data for the Svind magnetization of iron: aufberleadw bne 9002A V3 H in AT/m B in T 2500 1.55 3000 1.59 N = 600 3500 1.6 osga 1 mm 4000 1.615 30 cm, core length = 10 -1.2 [3]