Intuition behind fields in Transmission lines

[Amartansh]

TL;DR Summary

How can travelling wave exist on transmission line if wires are perfect conductors (how voltages can be different at different positions on one perfect conductor)?

How can traveling wave exist on transmission line if wires are perfect conductors (how voltages can be different at different positions on one perfect conductor)? I mean electric fiels should be zero on equipotential source. I know if length is too long compared to wavelength, we get phase difference on each point. But if all the connected points on conductor have same potential, how voltage/ electric field can vary and if electric field cannot vary then how current varies. Also, if inductance of line causes variation then how this inherent inductance is explained in these conductors? I know the classical reasons but looking better intuition and physical insight into this phenomenon.

 

[DaveE]

While the electric potential on the wire is zero, moving electrons create a magnetic field near the wire which interacts with the electric field near the wire. In fact the energy carried down the transmission line is really carried "around" (i.e. nearby) the transmission line. You will hear a lot about this when you get into the Electricity and Magnetism part of your physics education. You can not figure this out if you ignore the magnetic fields.

If you want a head start, look into "Maxwell's Equations".

 

[zoki85]

You seem to confuse electrostatic or/and magnetostatic state condition with electrodynamic case. The traveling waves on Tx lines propagate at speed close to the speed of light so distant points on the line need not to be at same potential and with same currents at the same time. For example, if constant DC source suddenly gets connected (switched on) to uniform loseless TX line, than the wave propagates without change of the shape along the line (and you would be kind of right). If the source is not constant, and line is still losess than the shape of the launched wave changes in accordance with the source and propagates as such. In reality the line is lossy and shape of traveling wave changes from point to point even in the case of switched on constant DC source. Such Transients (and more) on TX lines are described by the Telegrapher's equations