Talk:Electrical resistivity and conductivity

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Mistaken postulate in Definition section?[edit]

Just a quick question. Unless I misunderstand something, under the heading "definition", it seems like the discussion about the definition of resticivity mistakenly reverses the point. Resticivity is defined as R=V/I, which is an intrinsic property of materials, while p=R*A/l specifies, as I read it, the resistance of an OBJECT, which varies with its geometry and is thus determined by its geometry and the intrinsic property, R, of its substance. But the article states the opposite. Or what? I know nothing about the subject, so might just be misreading it. I.e. it says:

"The reason resistivity is defined this way is that it makes resistivity an intrinsic property, unlike resistance.", but the rest of the content indicates that the words have just been swapped by mistake. I will not correct it, since I am no expert, but I urge someone to correct it if it is a mistake.

You say "V/I is an intrinsic property of materials" but that's not true. A long thin copper wire has a different V/I from a short thick copper wire, even though both are copper. --Steve (talk) 12:06, 16 May 2016 (UTC)

Dubious phrase[edit]

There is a hypothesis that electron pairing in high-temperature superconductors is mediated by short-range spin waves known as paramagnons

This phrase caught my eye because of new term I made redlinked. I did some reading and found this text saying that paramagnons are in fact suppress superconductivity. So, how they can "mediate"? Does somebody have access to the footnoting article to verify what it actually says? Staszek Lem (talk) 20:22, 5 August 2016 (UTC)

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Resistivity of Deionized Water?[edit]

Appears to be wrong: low by 100X. The ref is behind a paywall. Can someone with access verify it? The usual value for well-deionized water is 18e7 ohm-cm, not 18e5 71.37.36.149 (talk) 02:50, 6 March 2017 (UTC)

There is another source here, which does indeed give 18 MΩ·cm = 0.18×106 Ωm = 1.8×105 Ωm – the figure given in our article (as well as in purified water). You might have been confused by the choice of units – this article uses Ωm rather than Ω·cm. No such user (talk) 13:22, 6 March 2017 (UTC)

Conductivity of air versus absolute or relative humidity[edit]

It is well known that experiments on static electricity work better under dry than humid conditions. The usual reason given is that humid air conducts electricity better than dry air, but if so does that depend chiefly on relative or absolute humidity? I would guess absolute, since that's what corresponds to the actual ratio of water molecules to air molecules. Another way of asking this question would be to ask, at a given absolute humidity, does the conductivity of air vary with temperature (which would change the relative humidity). I could not find tables of the conductivity or resistivity of air versus humidity in a cursory Web search, so I'm beginning to suspect that the answer may be more complicated, e.g. in addition to an effect on the conductivity of air, humid conditions (especially high relative humidity) may moisten the surfaces of otherwise insulating solid materials, making them more conductive, and thereby hastening the dissipation of charge otherwise than by actual conduction through the air. In any case, since the effect of humidity on conductivity of air is of great interest and practical importance, there should be a section on it, hopefully with a table or graph of reliable values, and/or an explanation of more complicated aspects such as those I conjecture here.CharlesHBennett (talk)

de:Elektrische Leitfähigkeit[edit]

Why is there one page for two terms?

that causes problems wit the interwiki links. --Manorainjan (talk) 16:24, 20 July 2017 (UTC)

As explained at Wikipedia:Wikipedia is not a dictionary, an article is about a concept or topic, not a word, so it is common for multiple very-closely-related terms to be defined in the same article. In many cases, it is not obvious whether articles should be merged or split, and there are debates / discussions about what to do. But each language's wikipedia is entitled to make its own independent decisions about which articles exist and what their scope is. If you think that the article should be split in two, you can propose that and make arguments for it, but if "German wiki did it differently" is your only argument, I think that's a very weak argument. Maybe this article should stay the same and German wiki should merge them! Or maybe different ways of organizing the information make sense in the different contexts, and problematic interwiki links are just an inevitable problem we'll have to accept. :-D --Steve (talk) 01:39, 21 July 2017 (UTC)

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