Talk:Voltage

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Voltage IS NOT potential difference

Voltage can only be expressed as potential difference if there is no change in magnetic flux. If there is a change in magnetic flux, along a closed loop there is a voltage>0 - this would be obviously impossible if voltage was potential difference. Please have a look at Electromagnetic induction, what is called EMF there is voltage or electrical tension.

I recently read in New Scientist, an article about memresistors, that the definition of voltage is the change in magnetic flux over time (dØ/dt). I've never seen that before. I do not doubt that a change in magnetic flux will cause a force on charges, hence a voltage, but the formula (definition) given also hints that any voltage implies a change in magnetic flux over time. I believe that's just wrong (i.e. imagine an ideal battery in a room with infinitive R - there is no change in flux. And even if R is less than infinity, the change in flux really depends on the capacity of the battery, not the voltage). I'm confused. In any case, this article should be mentioning magnetic flux more than it does. tobixen (talk) 01:34, 28 November 2009 (UTC)[reply]

Electric tension

I think voltage should be replaced with electric tension. "Voltage" is an, in my opinion, an unnecessary link to one specific unit of measurement. The electric tension stays the same, no matter if you measure it in Volts, Statvolts or other units you could think up, like the quite absurd btu/elementary charge ( $1{\frac {\rm {btu}}{\rm {e}}}=6.5851046\times 10^{21}{\rm {V}}$ ). What do you call the electric tension of a powerline? Kilovoltage? You don't call a length "footage" or "inchage", do you? Ospalh 15:17, 17 May 2007 (UTC)[reply]

Voltage is not an unnecessary link to one specific unit of measurement. The terms voltage and Volt both refer to the physicist Alessandro Volta. Similarly, the term "Newtonian mechanics" does not refer to one specific unit of force, the Newton. Both terms refer to an influential scientist in that field.Alhead (talk) 22:00, 11 July 2008 (UTC)[reply]

Sorry, fixed a link.Alhead (talk) 22:01, 11 July 2008 (UTC)[reply]

I doubt your analogy. Voltage is named after the unit, not after the physicist. Note how "Newtonian mechanics" isn't known as "Newtonage". OED shares my view, deriving voltage directly from Volt, not from Volta. dab (𒁳) 17:26, 2 September 2008 (UTC)[reply]

I'll accept that the term came from the unit, not the physicist; I guess I just assumed otherwise. However, regardless of Ospalh's opinion on the subject, the term "voltage" is used colloquially as well as in text books, engineering classes, and elsewhere. The electric tension of a power line would not Kilovoltage, it would be a voltage of 110 kilovolts. Similarly, you say it would be a voltage of 1.67043664 E-17 btu/elementary charge. Perhaps it is an unnecessary link to one specific unit, but since the link exists, Wikipedia should reflect that. 129.7.202.125 (talk) 22:00, 1 December 2008 (UTC)[reply]

Bad redirect

This redirect page has a history of pointing to different things:

None of these is satisfactory, because voltage is an electric potential diffrence, which is measured in volts. The article Volt is, in fact, mostly about voltage, which is an unacceptable confusion. Voltage should be its own article. Melchoir 11:42, 15 February 2006 (UTC)[reply]

Volt is the unit that represents Voltage, there is no need to merge these articles. Captain scarlet 00:44, 18 February 2006 (UTC)[reply]

Electric current and Ampere,

Electric charge and Coulomb,

Electric power and Watt,

Electrical resistance and Ohm (unit),

Electrical conductance Siemens (unit),

Capacitance and Farad,

Inductance and Henry (inductance),

Magnetic field and Tesla (unit)...

all have separate articles, and that's just in electricity. Electric field doesn't have an article on its unit, but presumably that's because the unit doesn't have a name. I'm sure I don't have to quote articles from other fields. Melchoir 01:21, 18 February 2006 (UTC)[reply]

No you don't, it is a good thing that all this units have their own article. In many cases I have linked an article to volt and it is to Volt that the links are clearly intended to link to, not voltage. Captain scarlet 13:45, 19 February 2006 (UTC)[reply]

I'm sorry, I may have misunderstood you... do you agree with my very first comment? Melchoir 22:18, 19 February 2006 (UTC)[reply]

Voltage does not reflect "the potetial difference" or "the current driving force" and hence is not a really good name. In non english speaking countries (france/germany/scandinavia) the word that translate to Tention denoted U is measured in Volts [V]. The frensh (who sould now SI) call it La tension électrique or just tension for short. --Oy5tein 14:57, 24 February 2006 (UTC)[reply]

I agree that "tension" is a more evocative name than "voltage", and the article Tension does note that it's sometimes used in English. But according to Wikipedia:Naming conventions (common names), we should use the most common English name for the article, and that is "voltage". The information about other languages is interesting, and it should go into the article when we create it. Melchoir 20:29, 24 February 2006 (UTC)[reply]

I concur to keep articles on the physics, i.e. voltage/potential difference/etc., separate from articles on the units in which they are measured. In voltage, simply state that in SI voltage has the unit volt and reduce the article on volt (and other units) to origin of name, when it was adopted into the unit system, present definition and realisation etc. and maybe relation to other units. Dalle 15:48, 16 March 2006 (UTC)[reply]

The correct technical term is Potential difference. Voltage is informal language. 80.136.204.122 23:57, 6 October 2006 (UTC)[reply]

Electromotive force (emf) also needs to be considered. I agree that the quantities being measured should be separated from their units, and that the one thing voltage should not redirect to is volt. Gene Nygaard 16:16, 30 March 2006 (UTC)[reply]

Yes, but voltage should redirect to the correct term potential difference. 80.136.204.122 00:03, 7 October 2006 (UTC)[reply]

Split

Okay, I've split this article from Volt. English Wikipedia is now roughly the 25th language to have separate articles on volts and voltage. I find it interesting that of all the interlang links I've found, none of them are apparently named "Voltage", in stark contrast with the interlang situation at Volt. Rather, most languages seem to call voltage "electric tension"; after finding a couple of English webpages on Google that recommend "electric tension" at English, I have made electric tension a new redirect to Voltage and added the phrase in bold to the top of the article.

Some of the interlang links, such as fr and ca, are technically not about electricity, but they launch into electricity almost immediately, so I've linked them; I think it's okay that those articles then link back to en:Tension or en:Potential difference. However, I'm going to go through the "electric tension" articles that currently link back to en:Potential difference and link them to en:Voltage instead. Melchoir 06:46, 9 April 2006 (UTC)[reply]

Equations for DC circuits

In the section on DC circuit equations, the following are listed:

V={\sqrt {9PR}}

V={\frac {P}{I}}

V=IR\!\

Multiplying equations 2 and 3 produces $V^{2}=PR$ , which contradicts with equation 1. I don't know enough physics to know if this is (somehow) right, or what would make it correct. However, I'm guessing that equation 1 is not correct, and will delete the 9.

(Comment largely copied from pre-split Volt)

Ealex292 06:52, 9 April 2006 (UTC)[reply]

Thanks for taking care of that! I guess I'll copy over more of the discussions at Talk:Volt that now belong here. Melchoir 07:06, 9 April 2006 (UTC)[reply]

Hydraulic analogy

The following is from Talk:Volt, since the material in question used to live at Volt:

Re: "water circulating in a network of pipes, driven by pumps in the absence of gravity, then the potential difference corresponds to the hydrostatic pressure difference between two points". The "hydrostatic pressure" hyperlink is redirected to "fluid pressure", perhaps because "hydrostatic pressure" is more narrowly, and I presume correctly, defined there as the pressure of a fluid due to the weight of the fluid, which makes the "absence of gravity" correspondence to "hydrostatic pressure" on the "Volt" page problematic. Perhaps the simple solution is to change the linked reference text from "hydrostatic pressure" to "fluid pressure"? I am new to both Wiki and physics, and perhaps there is more to this than I can see, but for anyone simply following the linked text, there is I think a problem.

jauntymcd@sprint.ca Oct 22, 2005

I changed to fluid pressure, as above. I also removed most of : "Voltage is a convenient way of quantifying the ability to do work without having to specify the amount of charge (the number of electrons or other particles) involved. This simplifies electrical calculations, where the number of particles that move is usually of no interest." I don't think it is helpful. The amount of charge might be relevant in talking about the voltage across a capacitor, but the voltage induced across a conductor by a changing magnetic field has nothing to do with quantity of charge.--agr 11:25, 2 December 2005 (UTC)[reply]

W/ some minor exceptions, this is a good discussion of voltage. However, there is nothing as to what voltage is rigorously. What is it about certain electrons that makes them different from others of lower/higher voltage?

Voltage is a property of an electric field, not individual electrons. See "Technical definition". An electron moving across a voltage difference gains energy, often measured in electron-volts.(hmmm maybe this belongs in the article) --agr 11:34, 2 December 2005 (UTC)[reply]

Melchoir 07:14, 9 April 2006 (UTC)[reply]

Ryan858 removed the statement that voltage is analogous to fluid pressure in the opening paragraph with the summary note that it was redundant. This may be mentioned in the main article but it is appropriate to expand on the opening paragraph in a article. Without it the opening paragraph is over-the-head of the average reader. I put the statement back. Rsduhamel (talk) 06:32, 12 March 2009 (UTC)[reply]

Suggestion?

wouldn't it be more accurate to use ∆V instead of V?

It might be more suggestive, but it's not quite standard. Do you know of any texts that use ∆V to differentiate voltages from potentials? Melchoir 04:17, 29 April 2006 (UTC)[reply]

Its a rather sticky thing. A volt is a relative term, really. The difference between two points in it of itself. Confusingly, the electrical pressure of a point in space is of the unit 'volt'. But you can't just measure it. What do you compare it to? You compare it with another point in space, and that is the voltage, as I'm to understand. The comparison between the relative electrical pressures is voltage. ∆V is usually used to describe the change in voltage. That is, a change in the measurement that is between two points. You can easily say that the voltage of a battery has changed from when it was new to when you tossed it because it was drained. That's more of a ∆V. Disclaimer: I'm an EE, not a physicist, which is a big difference. Kevin_b_er 00:28, 2 June 2006 (UTC)[reply]

Use the term potential difference to describe the voltage between any 2 points! 8-)--Light current 00:38, 2 June 2006 (UTC)[reply]

There would potentially be confusion with Delta-v.—An Sealgair (talk) 02:32, 16 October 2009 (UTC)[reply]

Voltage with respect to a common point - that easy?

Is there a way to tell an absolute voltage value? I can imagine that there are problems specifing one single ground at least in moments when a power plant transmission line is supposed to be connected to an existing intercontinental electricity network. Or is ground everywhere the same on our planet? --Abdull 15:56, 12 December 2006 (UTC)[reply]

Real_Potential_Difference_Number

http://en.wikipedia.org/wiki/Real_number

File:Real Potential Difference Number 1.svg
Belgium, France, Netherlands, others ?

Czech Republic, Germany, others ?

USA, others ?

Other possibilities?

Tsi43318 16:05, 27 February 2007 (UTC)[reply]

Eduardo informatico

es una persona que trabaja en sistemas fondeur

Error?

Under ways to measure voltage a potentiometer is given as one method... I realize that this coupled with other equipment can measure voltage, did they mean a galvanometer, coupled with a potentiometer? —Preceding unsigned comment added by 68.37.153.73 (talk) 21:44, 27 January 2008 (UTC)[reply]

Merge from potential difference

Please comment at Talk:Potential difference#Merge about editing that article into this one. --Gerry Ashton (talk) 16:54, 20 April 2008 (UTC)[reply]

Is this correct?

A while back an IP edited "Specifically, Voltage is equal to energy per unit charge." into the first paragraph. Can anyone verify that it's correct and in the right place? —Preceding unsigned comment added by Ryan858 (talk • contribs) 03:57, 12 September 2008 (UTC)[reply]

Yes, it's correct. I added a footnote. --Gerry Ashton (talk) 04:24, 12 September 2008 (UTC)[reply]