I have been taught in my machine's class that eddy current losses are proportional to the square of frequency*flux density, this seemed so fair that I never questioned this. But my machine design book mentions that
Induced emf = 4.44*freq*Max Flux Density * Area of flux path * No of turns, hence as long as supply voltage is maintained constant, the product of flux density and frequency remains constant even if frequency is changed, and hence there is no change in eddy current losses with frequency.
Now this is also in accordance with emf equation of transformer, at least it seems so, but how is that possible? If that's the case why would we go for high frequencies in eddy current heaters?
I mean, suppose I have source 1 of 230V, 50Hz supplying a coil wound on iron core, now if I replace source 1 with 230V, 100kHz, will the eddy current heating remain same? How that could be the case? Where is my (or book author's) interpretation of equations wrong?