Defines the relationship of voltage and flux as: E = N [df/dt] x 10-8 For sinusoidal voltage conditions, it is written: E = 2.22 ft FN X 10-8 or E = 4.44 BmAc FN X 10-8 where, E = Voltage desired Bm = Flux density of material in gausses. t = Total flux capacity of core Ac = Effective core cross-sectional area F = Design frequency N = Number of turns ft = 2 Bm Ac