In the structure shown below, all flux lines in the core are

Last updated: 7/10/2022

In the structure shown below, all flux lines in the core are assumed to cross the air gap. The structure dimensions are as follows: core cross-sectional area Am = 20 cm2, mean-path length em = 40 cm, eg = 2 mm, and N = 75 turns. The iron-core permeability can be assumed to be constant with ur = 4500. The coil current i (-30 A) is below the saturation level. Calculate the flux density in the air gap, (a) including the reluctance of the core as well as that of the air gap and (b) ignoring the core reluctance in comparison to the reluctance of the air gap.