Talk:Ampère's law

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This article should correctly be entitled 'Ampère's Circuital Law'.

Ampère's Law is a different law relating to the magnetic force that acts between two loops of electric current. (203.115.188.254 08:02, 18 February 2007 (UTC))

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[edit] Alternate form of Ampere's Law

Why is there no mention of \oint_{l} \vec B\cdot d\vec l=\mu_0I on this page? --70.81.118.123 06:23, 5 December 2005 (UTC)

Was here,but someone must have deleted it.--85.103.37.24 10:16, 19 January 2006 (UTC)

I put it back, they're integrated now. This page needs *work* and the terminolgy is all messed up. Particularly confusing is the difference between B and H. Not to mention that H is magnetic field density on the Maxwell's equations page, and magnetic flux density on this page.. I'm too confused to fix more. Fresheneesz 22:51, 3 February 2006 (UTC)

H is not magnetic flux density.....B is magnetic flux density..H is magnetic flux intensity..similar what electric field is in electrostatics...[vijin]

[edit] whats dA

What's da in the first formula?

I'd vote for an infintesimal part of the surface S. This is a surface itself. In French, the word "aire" is used for surface. I suggest to change da for ds.

I added the defintion from the page Maxwell's equations. This page needs to define ALL its variables - its in poor shape. Fresheneesz 22:59, 3 February 2006 (UTC)

[edit] Bad Units for vector D

I noticed that the page defines

\vec{D} \ = \ \varepsilon \vec{E}

as having units of A/m2. The units should in fact be coulombs/m2. When you do:

{\mathrm{d} \over \mathrm{d}t} \iint_S \vec{D} \cdot \mathrm{d} \vec{A}

the result of the integral is in coulombs. Taking the derivative with respect to time yields coulombs/sec or amperes. This is what we want, since

\oint_C \vec{H} \cdot \mathrm{d}\vec{l}

gives a current, as H has units of A/M and integrating that over length results in Amperes.

I mention this here so that someone else can change it. I am new to Wikipedia and don't want to screw up the original article. UPDATE: I HAVE CORRECTED THIS IN THE ARTICLE.