So, basically I can follow the math deriving E/B = c from Maxwell.
And I can calculate B and H from I: H = I/2*pi*r and B=uH. Easy.
So, for example I take a 2000 A, 50 Hz, current and a distance of 2 meter from that current in a round conductor.
H and B are set: H = 160 A/m and B = 0,2 mT...