Current through coils
Different currents at each end of a coil are easily explained.
A coil has capacitance to its surroundings distributed along its
length. And current flows from it radially.
Every coil has length. Both L and C are distributed. Therefore the
coil behaves as a transmission line. There are standing waves. Current
and voltage both vary with length.
The longer the line the greater the variation.
The line has phase-shift, Zo and attenuation resulting from wire loss
resistance and radiation resistance.
The line can have a resonant length. It then becomes a short antenna.
The whole business can be mathematically modelled.
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Reg, G4FGQ.
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