QUESTION 110 marks] A wrought iron bar 30 cm long and with area, x 104 m² is bent into a circular shape as shown in Figure 1. It is then wound with 600 turns of wire and has an air gap of Imm in length. The relative permeability of the core is 4000. Calculate the current required to produce a flux of 0.5 mWb, and determine the flux density in the core and air gap. Assume 5 percent increase in effective air-gap area due to fringing effect. [10 marks] N=600 30 cm, core length Figure 1 Wrought iron bar 1 mm A₁ = xx 10 m