Experiment with Ampere?s Law and the Current Element
The reason that a finite length current element may legitimately be used in the mathematics of calculating forces and energy between current carrying wires is because the current carrying element has canceling stored energy in it. This fact is demonstrated by an experiment conducted by the author. This experiment measured the inductance of several different shaped single turn coils. The measured value of inductance was then compared to the value of inductance calculated employing the integral of Ampere?s Law. It was discovered that by adjusting the length of the current element a match between the measured and calculated inductance could be obtained for all the single turn coils. The inductance of the current element, itself, was then calculated using the integral of Ampere?s Law. The inductance of the length required for the match was found to be zero. There are mechanisms in the current element that give up energy to supply the energy stored in it so that the net stored energy is zero.