I know that they move extremely slow in wire, http://www.youtube.com/watch?v=jbi7gJTPSXk) but how fast do electrons move in air in an electric spark/arc?

  • $\begingroup$ To be fair, the communication speed is high because the effective collision rate is high? So while their bulk drift speed is low, that they almost constantly bump into each other allows them to transmit information at much larger speeds. It's similar to pushing on the end of a rigid rod (very loose analogy). $\endgroup$ – honeste_vivere Feb 17 '17 at 14:28
  • $\begingroup$ Is there anywhere where I can find out what the speed is at various voltages, such as ten kilo volts? $\endgroup$ – Maxwell Baker Feb 17 '17 at 18:11
  • $\begingroup$ also is there any chart that show how magnetic fields would change the speed. $\endgroup$ – Maxwell Baker Feb 17 '17 at 18:12
  • $\begingroup$ I just noticed a punctuation error/typo. The first sentence should end with a period, not question mark. $\endgroup$ – honeste_vivere Feb 17 '17 at 18:20

The speed of electrons in metals is actually very high, around $10^5 ms^{-1}$. It is the drift velocity which is very slow, about $1mms^{-1}$. The electrical signal in the wire travels close the speed of light at about $10^8ms^{-1}$. See velocity of free electrons in a wire.

You need to specify the conditions in the arc. An electron accelerated through a potential difference of $300V$ has a speed of about $10^7ms^{-1}$.


If you mean electric arc welding or plasma cut that depends on the surrounding gas temperature of magnetic fields if there is such provideing pinch effect on the arc. The electron velocity is 20 000 times bigger than the particles. All depends on the specific conditions and arc.

  • $\begingroup$ The electron velocity is 20 000 times bigger than the particles. What does that mean? How can you compare velocity with diameter? $\endgroup$ – sammy gerbil Feb 17 '17 at 2:06
  • $\begingroup$ This answer needs serious revising as it is incomprehensible. $\endgroup$ – DepressedDaniel Feb 17 '17 at 3:18
  • $\begingroup$ Is there any charts online that show the speed at various conditions? $\endgroup$ – Maxwell Baker Feb 17 '17 at 18:13
  • $\begingroup$ Also what's the maximum electron drift speed in air? (with standard atmospheric air pressure) $\endgroup$ – Maxwell Baker Feb 17 '17 at 18:17

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