The Romer-Lewin ring with inductors (part 5b: Seeing the burden voltage on the scope)

Finally! My last video on the inductive ring.
Just to show how inserting a resistor in the ring alters the voltages. And to show the burden voltage of the UT61E on the scope.
Apart from some added noise (and a different selection of acquisition mode) that has increased the measurement by a couple of millivolts - affecting the smallest voltages the most - all measurements show an agreement with the theoretically computed values.
The theoretical values are computed starting from Faraday's law, and do not include any EMF in the loop: neither localized, nor distributed. All voltage drops take place at the interfaces between the copper conductor and the components (lumped inductor, lumped resistor), while no appreciable voltage drop happens in the copper conductor. There is no build up of voltage ('distributed EMF') in the copper coil because all the induced electric field in the copper has been obliterated by the coulombian electric field generated by surface and interface charge.
Ohm's law works perfectly fine in every part of the ring, while KVL only works in all those regions of space that do not include any changing magnetic flux. That is, KVL works in the measurement loops that the voltmeters/scope form with the nearest branch of circuit, but fails in the measurement loop that contains the other branch (and enclose the core).
More specifically, KVL fails completely in the ring itself, without any probes or voltmeters attached, because the voltage of one branch is different from the negative of the voltage of the opposing branch of the loop. The sum of the voltages is not zero - as KVL requires - but is instead equal to the EMF - as specified by Faraday's law.

[@copernicofelinis]

The burden voltage on the scope is at 06:30. (I hate videos where you have to search what is promised in the title 😊)

[@freemanrader75]

So what's going on here? I have one of those inside my Variac

[@copernicofelinis]

Toroidal transformers are everywhere, like parsley. Here it is used as a means to generate a sinusoidally changing magnetic flux.
If I had had a powerful enough magnet I could have attached that to my grandma's sewing machine and used that instead.

[@freemanrader75]

@@copernicofelinis so could you theoretically use a sinusoidal alternating magnetic field to replace the moving magnets of a generator? Like make a solid state generator that use 2 alternating sinusoidal magnetic fields at 90* to eachother.

[@copernicofelinis]

​@@freemanrader75 I believe the point of a generator with moving magnets is that to convert mechanical energy (used to move the magnets) into electrical energy. If we remove the magnets and replace them with an electrically generated variable field, we end up with a transformer.