# Ampere's Law

1. ### Emz19

11
Could someone give me a word definition of Ampere's Law as I have googled some definitions and they all seem a bit confusing. Thanks :)

2. ### ZapperZ

29,860
Staff Emeritus
You need to tell us what you found, and what exactly that you found "a bit confusing". Otherwise, we might give you the same definition and your confusion would not have been solved.

Tell us what you know, what you have understood, and what exactly you didn't.

Zz.

1,919
4. ### BOAS

370
For any current geometry that produces a magnetic field that does not change in time,

$\Sigma B_{||}\Delta l = \mu_{0} I$

Where $\Delta l$ is a small segment of length along a closed path of arbitrary shape around the current, $B_{||}$ is the component of the magnetic field parallel to $\Delta l$, I is the net current passing through the surface bounded by the path, and $\mu_{0}$ is the permeability of free space. The sum of all these must be taken around the closed path.

Personally, I find the best way to understand is to do.

5. ### ZapperZ

29,860
Staff Emeritus
UltrafastPED, BOAS: aren't you at all curious to figure out first at what level the OP could comprehend?

Zz.

6. ### BOAS

370
On reflection, finding out the level to pitch an answer at first would be most useful.

Will try to use this approach on any further questions I feel capable of assisting with.

7. ### Emz19

11
Thank you everyone. I am revising for an exam and i think i was just overloaded with the different ways of defining Ampere's Law on google and I just wanted the easiest way to state it as well as a way to best comprehend it. I have found all of your answers helpful and BOAS I now know for sure what each notation means. UltrafastPED thank you, those links are a great help and ZapperZ thank you for your concern to help me in the best way possible. I am sorted now, thanks guys :)