Richard Harrison wrote:
Owen Duffy wrote:
"In the same vein, I saw an assertion without sufficient qualification
that in a transmission line, 50% of the energy is stored/contained in
the electric field and 50% in the magnetic field. Again, general
statements from specified cases."

Now we accept that energy travels a guided path as an EM wave. The
electric and magnetic fields of a wave alternately contain the energy of
the wave. When the electric-field is at its maximum, the magnetic-field
is at its minimum, and vice versa.

In addition:
Assuming ideal TEM waves, the B-field (magnetic) is always
orthogonal to the E-field (electric) and both are orthogonal
to the direction of travel. The power associated with the
ideal TEM wave is ExB in watts (no vars). A TEM wave travels
at the c' = c(VF) speed of light and cannot travel at any other
speed. If it slows down or stops, it is not longer a TEM wave
and has necessarily been converted to some other form of energy.
Energy "sloshing" back and forth between reactances is NOT TEM
energy.

The principle of superposition gives us permission to treat
the forward traveling wave and reverse traveling wave separately
and superpose the results. Superposing the results does NOT
change the nature of the TEM waves. The fact that the net total
fields are no longer orthogonal gives the illusion that there
exist vars in the circuit but they are only virtual vars based
on virtual voltages and virtual currents. There are no vars in
ideal TEM waves in ideal lossless purely resistive Z0 transmission
lines. The forward traveling wave TEM fields have no effect on
the reverse traveling wave TEM fields as long as a physical
impedance discontinuity is not encountered.
--
73, Cecil http://www.w5dxp.com