2. Figure 1 shows the magnetic circuit of a relay. When each of the air gaps are 1.25 mm wide find the mmf required to produce a flux density of 0.75 T in the circuit. Use the B-H curves 1 cm 1 cm Airgap 1.25 mm 20 20 cm Mild steel 1.8 Cast-steel 1 cm 0.8 cm 1.6 Silicon iron 1.4 Mild steel armature 8 cm 12 Flux density, B(T) 1.0 10 0.8 Cast iron 0.6 1 cm] 0.4 0.8 cm Cast iron magnet Air gap 0.2 1.25 mm Figure 1 0 1000 2000 3000 4000 5000 6000 7000 Magnetic field strength, H(At/m) B-H curve