Talk:Potential difference

I added this equivalent definition which was removed:

the amount of work that a unit charge that flows from the first point to the second can perform

since I find it more intuitive: one rarely moves a charge from one pole of a battery to the other, but one often exctracts energy from the electrons which flow naturally between the poles. Higher voltage means you get to extract more energy per electron.

In the explanation of emf, I put "force" in quotes, since the emf isn't really a force.

I added information about capacitors and coils and reintroduced the information about transformers that was deleted. AxelBoldt

With apologies to AxelBoldt, I have removed the following paragraphs:

Since the current I is defined as the amount of charge per time, and potential difference V is energy per charge, the product VI equals energy per time, which is known as power.

In a capacitor, the potential difference between the two plates is proportional to the charge on the plates; the proportionality constant is the capacitor's capacitance.

The voltage at the ends of an induction coil is proportional to the time rate of change of the current flowing through the coil, and is directed so as to slow down this change. The proportionality constant is the coil's inductance. By using alternating current and combining two coils of different inductances, it is possible to transform between high and low voltages. These transformers are important in electric power transmission since power losses are minimized if high voltages are used, which are however undesirable in the home.

I think these are better discussed in the individual articles on power, capacitor, inductor and transformer. -- Heron

Removed this line:

In mechanical systems the potential difference is the velocity difference.

Eh? What?

Potentiometer = potential meter?[edit]

Did potentiometer originally refer to a voltmeter? Obviously it doesn't anymore, but someone put it in the article as such, and I read the term in an Isaac Asimov short story as a meter that measured (positronic) voltages. - Omegatron 19:14, Jun 8, 2004 (UTC)

Yes. The original potentiometer was a type of bridge circuit for measuring voltages. The target voltage is connected across a piece of resistance wire, and a standard electrochemical cell of known voltage is then shorted across a variable-length section of the resistance wire using a sliding contact. The contact is moved until no current flows into or out of the standard cell, as indicated by a galvanometer in series with the cell. We then know that the voltage across the selected section of wire is equal to that of the cell. It is then just a matter of calculating the unknown voltage from the cell voltage and the fraction of the resistance wire that was shorted to the cell. The galvanometer does not need to be calibrated, as its only function is to read zero. -- Heron 19:41, 8 Jun 2004 (UTC)

Merge voltage[edit]

I merged the voltage section with volt. I think it makes more sense there than at electrical potential.--agr 11:10, 9 September 2005 (UTC)[reply]

The formula letters[edit]

Wouldn't it be nice to add the formula letters in parentheses after the names of each physic conception (for an example "Potential difference (U)", instead of just "Potential difference", and "Electric charge (Q)" instead of just "Electric charge"), it would make everything about physics much easier to read for those who didn't learn physics in English but otherwise speak english well, and help them to learn the physics-jargon. Those formula letters are international, taught everywhere but the english words for the conceptions are not. --Satúrnus 14:13, 9 September 2006 (UTC)[reply]

Yes why not? I cant see any harm in that.--Light current 22:51, 9 September 2006 (UTC)[reply]

link[edit]

The link no longer goes where it is supposed to so I think I am going to remove it.

The page is viewable here. Can we link to the Internet Archive? Pediacycle 02:43, 7 August 2007 (UTC)[reply]

Real_Potential_Difference_Number[edit]

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 15:19, 28 February 2007 (UTC)[reply]

Help![edit]

I need help with the following problem but I am oh so stumped. How do I find the Voltage of the Point on this diagram? Two other points are shown with their respective co ordinates relative to the origin. The charges on these points are in brackets (parenthesis whatever): Tourskin 01:58, 28 April 2007 (UTC)[reply]

Any suggestions please...Tourskin 19:50, 28 April 2007 (UTC)[reply]

Merge[edit]

Because potential difference and voltage are exactly the same physical concept, the two articles should be merged. After the merge, people going to the potential difference article would be redirected automatically to the voltage article. --Gerry Ashton (talk) 16:51, 20 April 2008 (UTC)[reply]

potential difference can also apply to other situations then with electricity. maybe its better to change the main heading of the artical in a more generic direction and expand the part of "Other types of potential difference"?Yourilima (talk) 19:47, 21 May 2008 (UTC)[reply]

I hate to say it, but the tag helps the article. I would have hated the redirect, but after your explanation, it does make sense, and was actually what I was looking for. But wilma is correct, potential difference is a property of field lines, not necessarily electrostatic fields, but also gravity. However, I am in favor of a link at the top like disambiguation: for the specific article about electrostatic potential difference, see voltage. Biologicithician (talk) 22:05, 25 October 2008 (UTC)[reply]

I have done as Biologicitician has suggested. While others have chimed in to confirm my impression, that voltage and potential difference are the same, no one has provided a convincing source to show that all fields of science and technology agree. --Gerry Ashton (talk) 22:52, 25 October 2008 (UTC)[reply]

Voltage is incorrect (or is it ?)[edit]

Voltage is not a scientific term and is considered a laymens term by the scientific community. Other than the name difference, potential difference and voltage are the same thing, only the name is different. I'm amazed that the voltage article is so long even though you cannot write voltage down in place of potential difference on a physics paper and pass. —Preceding unsigned comment added by 130.15.86.51 (talk) 14:52, 5 July 2008 (UTC)[reply]

you are right, the voltage article should be moved. --dab (𒁳) 17:37, 2 September 2008 (UTC)[reply]

No, this is not exactly correct. The term "voltage" (or, better, "voltage difference") is universally used in electronic and electrical engineering, and in very many physics experiments, to describe a well-specified scientific concept. Apart from anything else, "voltage" is what is measured on a "voltmeter". Science is concerned with the accurate description of reality, and voltmeters are part of the reality that science has to describe. Whether physics textbooks and physics teaching give correct explanations of what voltage really is, and whether they write down a correct formal definition of voltage, are other issues. Think about the following question: " If physicists cannot explain the concept of voltage and/or do not regard it as a scientific concept, how can anybody trust them to correctly interpret the results of physics experiments that use voltmeters ? (RGForbes (talk) 13:42, 14 April 2009 (UTC)) (Richard)[reply]

Why reconstruction has been needed[edit]

I hope no-one is going to mind, but I have reconstructed this article in the light of changes made in other electrical pages in Wikipedia. There were a number of things in the article, and there are also a number of things on this talk page that - from a research science point of view - are at least 50 years out of date. I appreciate that people may have been following textbook/teaching definitions, but some of these must also be at least 50 years out of date. Looking at the page in its previous state, it seemed to be serving two purposes. First, it dealt with the specifically electrical problem of the meaning of the term "Potential Difference" in the context of electrical circuits. Second, it dealt with other examples of potential. But it seems to me that these other examples do not have the same degree of ambiguity involved as the electfical case does. Also, if people are interested in gravitational potential difference, they are more likely to go to gravitation first. So I have omitted most of the specific examples. (RGForbes (talk) 13:42, 14 April 2009 (UTC)) (Richard)[reply]

Terrible article[edit]

I can't believe that the article is so long and doesn't actually mention what "potential difference" is. It repeatedly states that it's not "voltage". Great. What is it? MisterSheik (talk) 23:54, 5 June 2009 (UTC)[reply]

This article is unreferenced. Frankly, I just don't believe what it says. It should just be redirected to Voltage, because it has nothing of value in it. The article that might be a candidate for a real merger to "Voltage" would be "Electric potential". --Jc3s5h (talk) 00:06, 6 June 2009 (UTC)[reply]