B Why is the net acceleration of an electron in a conductor zero?

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The net acceleration of electrons in a conductor is generally zero due to constant collisions that balance forces in opposite directions. When current flows, the drift velocity of electrons becomes non-zero, indicating that they have accelerated. While the average drift velocity can be considered constant in steady current, it varies when current is initiated or altered. Additionally, classical electromagnetism treats current as a continuous flow, while quantum mechanics would provide a more accurate model of electron behavior. Overall, the discussion highlights the complexity of electron motion in conductors, emphasizing the distinction between average drift velocity and instantaneous acceleration.
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Is it because due to all the collisions in every direction, there's always a force that is opposite to another force? Hence acceleration is zero?
 
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Turn your room light off. No current is flowing in the wire and the electron drift velocity is zero. Turn it on and the electrin drift velocity will be a few millimeters per second. The electrons must have accelerated.

Perhaps you had a specific situation in mind? Because the statement you asked about isn't generally true.
 
Ibix said:
Turn your room light off. No current is flowing in the wire and the electron drift velocity is zero. Turn it on and the electrin drift velocity will be a few millimeters per second. The electrons must have accelerated.

Perhaps you had a specific situation in mind? Because the statement you asked about isn't generally true.
Isn't the average drift velocity of an electron a constant value? Hence, shouldn't its acceleration be zero (since velocity is constant)?
 
atharba said:
Isn't the average drift velocity of an electron a constant value? Hence, shouldn't its acceleration be zero (since velocity is constant)?
As I pointed out in post #2, the drift velocity is zero when there is no current and non-zero when there is current. So the electrons must accelerate when the current is turned on, and no, the drift velocity is clearly not a constant value.

The drift velocity is a constant value if you are considering, for example, a steady current. It isn't in general. That's why I asked if you were thinking of a particular scenario.
 
atharba said:
Isn't the average drift velocity of an electron a constant value? Hence, shouldn't its acceleration be zero (since velocity is constant)?
In a crude model where the electrons are drifting through the wire at a constant speed, then (clearly) there is no acceleration. Why would that be a question?

That said, classical EM tends to treat a current as a continous flow of charge. To model the electrons themselves would need QM (Quantum Mechanics). And that's a different ball game.
 
Even with a constant drift speed there is still acceleration around a bend in a wire.
 
Dale said:
Even with a constant drift speed there is still acceleration around a bend in a wire.
... and in one complete circuit of the wire, the total acceleration is zero.
 
Dale said:
Even with a constant drift speed there is still acceleration around a bend in a wire.
Due to the magnetic field produced by the current in the wire.
 
Gavran said:
Due to the magnetic field produced by the current in the wire.
Typically due to the electric field produced by the surface charges on the wire. There is a pretty decent amount of literature on this topic.
 
  • #10
PeroK said:
... and in one complete circuit of the wire, the total acceleration is zero.
Unless, perhaps, one is monitoring charge carriers circulating in the evacuated tubes of a particle accelerator.

Admittedly, for a decent accelerator, the velocity change can be quite small while the momentum change is significant.
 
  • #11
On the slightly philosophical side, it's rare for anything to have net acceleration if you watch it long enough. Things that start tend to stop somewhere, eventually, or maybe return to a previous state like a planet in orbit. IDK, maybe a solar wind particle that makes it into deep space?
 
  • #12
Dale said:
Typically due to the electric field produced by the surface charges on the wire. There is a pretty decent amount of literature on this topic.
Can you recommend something that can be found on the internet?
 
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