Electrical Machine

An iron ring of mean length 1.2 m and cross sectional area of 0.005 m² is wound with a coil of 900 turns. If a current of 2 A in the coil produces a flux density of 1.2 T in the iron ring, calculate: i) The mmf ii) Total Flux in the ring iii) The magnetic field strength iv) The relative permeability of iron at this flux density.