Electric field in coaxial cable

AI Thread Summary
In a coaxial cable, the electric field is primarily axial within the conductors, with a perpendicular component between them, influenced by surface charges. The discussion highlights a contradiction in the propagation of TEM waves, where Ohm's law suggests a current flow in the same direction as the electric field. In an ideal scenario with infinite conductivity, the propagation is purely TEM, implying no longitudinal electric field component. The question arises about the force that drives charge flow in this ideal case. Understanding these dynamics is crucial for comprehending wave propagation in coaxial cables.
oocelik
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Every physics books show that wave prograpation in coxial cable is TEM wave, like in the picture. But we know that J=σ E from ohms law, which says current in same direction with E field, which is not the case here. What do you think the reason is ?

UzJYy.png
 
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Hello Dale,

Thank you for the reply. But I am talking about the ideal case where the cable has infinite conductivity and progpagation is pure TEM wave, which makes it sure that there is no "longitudinal" (i.e Ez=0) along the cable by definition. In this case, what force acts on the charges to flow down the cable ?
 

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