Talk:Drift velocity

No electrons ever leave the switch
I believe the statement that no electrons crossing the contact point in the switch leave the switch, could be misleading to newbies. After all, we have computed an average velocity over quintillions of electrons, and the movement of a small fraction of them is a disproportionate part of the actual movement. So I have edited in a minor change in wording which might be less likely to mislead. Jethomas5 (talk) 15:14, 21 August 2022 (UTC)


 * Those were good changes. In the future, please add new talk sections at the bottom of the page. Constant314 (talk) 18:24, 21 August 2022 (UTC)

Untitled
i think this article is only a stub, so i put the tag on the test.

As it relates to guiding center drift theory
I think more discussion as it relates to Guiding center drift theory, since essentially the whole theory is essentially about finding "drift velocities". For now, I'll add Guiding center to "see also" IlyaV (talk) 02:39, 18 February 2010 (UTC)

Many information is absent.


 * Equation Error:

∂Q = (nAv)q is surely not correct. The right-hand side is equal to the current, not the change in Q. Either the LHS should read "I" or the RHS should include "dt" in the numerator. -- Anonymous

More changes are desirable
I just made some cosmetic changes now, but more changes are necessary. Probably rho for charge density is confusing in a context where rho is commonly used for specific resistivity. The article is also incomplete. I would have expected a relation with the relaxation time tau here. /Pieter Kuiper 11:44, 20 September 2007 (UTC)

Electron velocity
I just redirected this term to here, as they are essentially the same aren't they? The text of the article is below.


 * Electron velocity is a very important value in computing. Electron is the subatomic particle responsible for electromagnetic field, that's the way to transmit information in electronic hardware. In a metallic atom the electrons on his orbit are relatively free to move from an atom to one other; this movement is cause of current, which is an electron's flow.
 * Electron velocity is a very important value in computing. Electron is the subatomic particle responsible for electromagnetic field, that's the way to transmit information in electronic hardware. In a metallic atom the electrons on his orbit are relatively free to move from an atom to one other; this movement is cause of current, which is an electron's flow.


 * According to relativistic model electron in an hydrogen atom would be moving at 2.42 x 108 cm/sec.


 * For now, the most widely-used material with high electronic velocity is silicon, but faster ones are possible:
 * Gallium arsenide
 * Indium(III) phosphide
 * Indium gallium arsenide



Assessment comment
Substituted at 13:51, 29 April 2016 (UTC)

Dimensional Analysis
please check dimensions.

THE ASG.

106.192.176.37 (talk) 21:49, 20 September 2016 (UTC)

Variables
I noticed that this article uses a lowercase "u" for drift velocity. However, many textbooks use v or vd for drift velocity. In fact, vd is used in the Wikipedia article on current density. I would like to propose that we switch to vd throughout this article. What do other people think? Is there a good reason for using "u"? Navigatr85 18:08, 18 May 2018 (UTC) — Preceding unsigned comment added by Navigatr85 (talk • contribs)

The article is a bit misleading
It is currently claimed that "In general, an electron will propagate randomly in a conductor at the Fermi velocity. An applied electric field will give this random motion a small net flow velocity in one direction.". This is wrong. In the free or nearly free electron model, the free electrons (i.e. not the core electrons tightly bound to the nuclei) obey Fermi-Dirac statistics as well as Pauli's exlusion principle. This means their velocities range from 0 up to roughtly the Fermi velocity. So, we cannot really speak of an electron velocity in general, although we could speak of an average velocity but this would serve no purpose whatsoever. Instead, only the electrons that have a momentum near the Fermi momentum can take part in electrical conduction. In this sense, it is only these very few free electrons that have such a velocity that indeed propagate at the Fermi velocity. This is far from an electron in general, even free ones.

Thus a possible way to fix the current Wikipedia sentence could be something like "Following the free electron model, in a conductor the few free electrons that can take part in electrical conduction propagate randomly in at speeds near the Fermi velocity. An applied electric field will perturb the electrons that are going in the field's direction at the Fermi velocity, to change their momentum in the opposite direction with approximately the same speed. The net result is a small drift velocity in the opposite direction than the electric field." — Preceding unsigned comment added by 176.163.163.86 (talk) 11:37, 3 January 2019 (UTC)

Physics
Why Current and the direction of flow of electrons are Opposite? 2409:4043:61D:8F96:5115:2CDD:6B7D:63B6 (talk) 02:12, 29 January 2022 (UTC)

Darkmode
The two calculations above and below "Dimensional analysis" (in the subchapter "Numerical example") can't be seen if using darkmode. I would change it, but honestly I don't no how lol 85.94.241.175 (talk) 13:03, 29 September 2022 (UTC)

Wiki Education assignment: 4A Wikipedia assignment
— Assignment last updated by Mkomboti (talk) 18:20, 10 April 2023 (UTC)

Numerical example
I think there's an error here. If the charge on an electron (q) is 1.609x10^-19 coulombs, then one coulomb is the charge on 1/q (6.24x10^18) electrons. If a current of one ampere corresponds to a 'drift' of one coulomb per second, then in the second last paragraph, wouldn't 3x10^18 electrons flow across the contact point twice per cycle, rather than 3x10^16? George963 au (talk) 02:55, 8 October 2023 (UTC)


 * Charge = current x time. The time is 1/120 second.  So, the numbers are about right.  However, it has almost nothing to do with drift velocity. Constant314 (talk) 04:34, 8 October 2023 (UTC)

Numerical example
Source for the claim that copper is the most popular conductor? Aluminum yearly production exceeds copper. Aluminum-zinc strands supported by steel core is popular for grids, though contested by copper in transformers, houses, devices, etc. 08:21, 30 December 2023 (UTC) — Preceding unsigned comment added by 2600:8804:6757:9200:1C96:11C4:BC56:BFD4 (talk)