What is the speed of electric current?

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Electric current is primarily characterized by the drift velocity of electrons within a conductor, which is typically only a few centimeters per second. While electric fields propagate at nearly the speed of light, the actual flow of electrons is much slower. High current densities or specialized conductors could theoretically increase drift speeds to relativistic levels, but this would require extreme conditions. Such advancements might also lead to the emission of high-energy radiation and potential applications in space propulsion. Understanding these concepts is crucial for grasping the complexities of electric current in physics.
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My teacher taught me electrons(current) inside conductor don't flow apace but they drift inside it. This drift in one direction due to electric field is called drift velocity. But now I m reading
"Electric current flows very fast through any conductor, resistor, or semiconductor.
In fact, for most practical purposes you can consider the speed of current to be the
same as the speed of light: 186,000 miles per second. Actually, it is a little less."

Oh man ! physics sucks me :D
 
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Electric fields travel very fast but the electrons making up the current generally drift at very slow speeds.
 
You can calculate it, I just forgot how!

If memory serves me right, it's usually few centimeters per second for normal current densities.

It will take an incredibly high amount of current and/or very fine strand of conductor to take the drift up to relativistic speeds - if only there's such superconductor that can handle such extreme current density. But if it was possible, it might emit high energy radiation as well as appreciable amount of thrust (that could you could utilize for space propulsion)
 
I was using the Smith chart to determine the input impedance of a transmission line that has a reflection from the load. One can do this if one knows the characteristic impedance Zo, the degree of mismatch of the load ZL and the length of the transmission line in wavelengths. However, my question is: Consider the input impedance of a wave which appears back at the source after reflection from the load and has traveled for some fraction of a wavelength. The impedance of this wave as it...
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