Calculate flux density at the pole center (Bg₎ in Wb/m², from the following data:

no. of pole = 4

slot pitch = 43 mm

slot opening = 21 mm

gross length of core = 480 mm

pole arc = 180 mm

length of airgap = 6 mm 

flux per pole = 0.056 Wb

no. of ventilation ducts = 8

width of each ventilating duct = 12 mm 

carter's coefficient for slot = 0.42

carter's coefficient for ducts = 0.28