You say “Twisted Pair” …
I say … not necessarily. Or rather: that is what my quad core processor said, just prior to saying overheat / overload and defaulting, whilst doing this quickie simulation in Excel.
The picture below shows the intensity of the magnetic field just in the vicinity of the outer insulation of a TWISTED QUAD. Not “Pair” but QUAD – like the number “4″.
The resulting graph, on the vertical axis, show right cork-screw values of the magnetic field intensity. The more higher up on the vertical axis, the mor intense the value of the “right turning” magnetic field.
The negative values on this vertical axis show the intensity of the values of the magnetic field intensity, but turning in the anti-cork-screw diretion. The more lower and down you go on the vertical axis, the more intense the value of the “left turning” magnetic field.
Now, a cross section of a “quad” of wires resembles more or less a square cross section, as you can see when looking at this graph “top-down”. Essentially, it is a representation of four wires.
The current flow in the wires is ORGANIZED as follows:
” + ” ; ” – “;
” – ” ; ” + “;
Now, take a very close look at the boarders of the rectangle cross section, as “seen from above”.
What can you tell me about the values of the resulting magnetic field flux (read the values from the vertical “Y” axis).
Fairly low values, and mostly compensated out / nulled out, or at least of very low values,
ARE THEY NOT ??
Now comes the killer question:
WHAT IS THE INDUCTANCE of a 1 meter length of such a cable ?