The original statement is "The drift velocity of electrons in a metallic wire will decrease, if the temperature of the wire is increased.". My understanding is, the temperature of a wire increases because of electron collision which increases it's resistivity.

But, if drift velocity is the speed at which electrons collide, shouldn't electron collision increase with drift velocity?

  • 1
    $\begingroup$ I think the causality is the other way around: more collisions means lower drift velocity. Jut think of an electron being freely accelerated by a potential difference in empty space and no collisions. $\endgroup$
    – hyportnex
    Jul 30, 2022 at 12:33
  • $\begingroup$ @hyportnex Thanks for clearing my doubt, please post your comment as an answer. It genuinely helped me. $\endgroup$ Jul 30, 2022 at 12:59

1 Answer 1


Holding temperature constant, an increase in drift velocity will result in an increase in frequency of collisions.

Holding drift velocity constant, an increase in temperature will result in an in crease in frequency of collisions.

A reasonable analogy here would be like trying to bike through a parking lot (cold wire) vs. bike across a busy street (hot wire). If you increase the speed at which you bike in either scenario, you increase the chance of hitting a car. But going fast in a parking lot could certainly lead to fewer collisions than going slow across a busy road. It all depends on the what you're holding constant (hint: in this case it probably the $\vec{E}$ field)


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