Talk:Resistivity
From Wikipedia, the free encyclopedia
 |
This article is within the scope of WikiProject Physics, which collaborates on articles related to physics. | |
| ??? | This article has not yet received a rating on the assessment scale. [FAQ] | |
| ??? | This article has not yet received an importance rating within physics. | |
|
Please rate this article, and then leave comments here to explain the ratings and/or to identify the strengths and weaknesses of the article. |
||
Contents |
[edit] resistivity of Al
After searching other locations, I'm finding very different versions of resistivity for Al. Something closer to 2.6 or 2.8 rather than 2.282... --Hobit 14:19, 11 October 2005 (UTC)
- –Fixed. I used the value from aluminium, which was taken at 20°C. This is equivilent to 293K, as used in this article). —deanos {ptaa*lgke} 15:18, 15 October 2005 (UTC)
[edit] References
The table of resistivity values looks exactly like the one in my physics textbook (Physics for Scientists and Engineers, with Modern Physics by Serway and Jewett). Is there a missing citation here or am I missing something? Mahsmanj
- I've added references for most of the materials, and for those where I couldn't I've moved them from the article to here. I also redirected Table of resistivities here, because the table here was exactly the same.
| Material | Resistivity (ohm metres) | Temperature coefficient per kelvin |
|---|---|---|
| Chromium | 1.8 × 10-7 | .0000059 |
| Tin | 1.15 × 10-5 | .0042 |
| Silver, German | 3.3 × 10-5 | .0004 |
| Seawater | 2.0 × 10-1 [1] | ? |
| Pure water | 2.5 × 105 | ? |
| Human skin | approximately 5.0 × 105 | ? |
Kevin 09:30, 4 May 2006 (UTC)
[edit] Volume?
Does anybody know how resistivity relates to the volume of an object? That is, if I had something that looked more like a sphere than a thin wire, and wanted to calculate its resistance using its resistivity, how would I do it?
- Its wikipedia custom to sign your name with four tildes ~~~~, welcome to wikipedia. As for your question, I think you could calculate it with an integral if you really want to : ) . Start by approximating it as a series of circles with some thickness dx, where the thickness of circles in the series goes from 0 to the radius (of the sphere). Add all the resistivities of those circles up, and take the limit as the distance between different sized circles goes to 0.
- That would probably be a difficult integral to figure out how to set up, but you could easily approximate it without taking such a limit. Simply approximate the sphere as say 5 different circles, and see what the resistivity comes out to. Fresheneesz 22:50, 27 May 2006 (UTC)
[edit] combining resistivity and conductivity tables
I think it would be better if we combined the tables of resistivity and conductivity since they are so fundamentally linked. Please discuss this at Talk:Electrical conductivity. Fresheneesz 22:52, 27 May 2006 (UTC)
