I am trying to calculate the flux density of an air gap in an electromagnet. I am following this page that calculates the flux density in a C core with an air gap. My confusion is that I am using 50Hz AC instead of DC I have control over the voltage amplitude since I would be using a variac to do my initial tests. Would the calculations differ for AC, my guess is that it would be different since the AC impedance of the coil would come into play and that would change the MMF(magneto-motive force) value. I have a C core of Electrical steel (laminated) with the following parameters Permeabity of core = 5.0×10−3 H/m Cross section Area = 1cm2 Magnetic Path Length = 19cm Air Gap length = 1cm Flux Density needed in air gap = 1Tesla Would appreciate your thoughts on how to go about doing this calculation. Thanks in advance.