CityBird

Must a core for a 100mH/10A inductor have a larger cross section than a 100mH/1A inductor? I am confused here. Ampere's law says that the Field strength is proportional to the current flowing though the windings (H= n.I/lm). Core saturation B/H (permeability, μ in fact) at the other hand does not depend on the actual core area. One may logically conclude that a 10A inductor could be assembled with the exact same core, at least if one would be able to fit the thicker wire. This seems counter-intuitive to me.

I would like to know if my understanding of capacitors is correct. a) If you move the plate of a charged hypothetical capacitor further apart from each other the voltage must increase since V = Q/C and C = εA/d. The stored energy E = 1/2CV² increases because V² increases faster then the capacitance C drops. My understanding is that this energy rise strictly comes from the mechanical energy from the lateral pull. b) If one would insert a dielectric with an εr of 2 into an unconnected and charged air plate capacitor εr of 1, capacitance would obviously double. There's however no conversion of energy (At least that's my line of thought) since the work done is at a 90 degrees angle with respect to the capacitor. Also when you would remove the dielectric again everything is as before. So one can't speak about energy loss and gain. The drop in voltage must therefore come from inside. My understanding is that the dielectric is charged due to the electric field inside the capacitor. This produces a voltage that counters the already present voltage on the plates which results in an overall voltage drop. Is a) and b) correct?