Deriving Biot Savart's law from Ampere's law

Click For Summary

Discussion Overview

The discussion revolves around the derivation of Biot-Savart's law from Ampere's law, exploring the mathematical connections between these two fundamental laws in electromagnetism. Participants express varying levels of understanding and seek clarification on the derivation process, with references to both theoretical and practical aspects.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant seeks help on how to derive Biot-Savart's law from Ampere's law, referencing a textbook for guidance.
  • Another participant shares a link to a proof but expresses skepticism about its validity, suggesting that the connection between the two laws is not straightforward.
  • A different participant critiques the linked proof, indicating that it does not adequately derive Biot-Savart's law from Ampere's law and highlights the ambiguity in the definitions of these laws.
  • One participant proposes a specific form of Biot-Savart's law and suggests a method involving the curl of Ampere's law and Fourier Transform techniques to derive it.
  • A college freshman expresses confusion about the previous explanation and requests a more accessible derivation approach, indicating familiarity only with the integral form of Ampere's law.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the derivation process, with multiple competing views on the validity of the proposed methods and the clarity of the explanations provided. The discussion remains unresolved regarding the best approach to derive Biot-Savart's law from Ampere's law.

Contextual Notes

There are limitations in the discussion, including varying levels of mathematical understanding among participants, differing interpretations of the laws involved, and the need for specific boundary conditions in the derivation process. Some assumptions about the forms of the laws and the mathematical techniques required are not fully articulated.

Who May Find This Useful

This discussion may be useful for students and individuals interested in electromagnetism, particularly those seeking to understand the relationship between Ampere's law and Biot-Savart's law, as well as those looking for different perspectives on mathematical derivations in physics.

McLaren Rulez
Messages
289
Reaction score
3
Can anyone help me with this? My textbook (Young and Freedman's University Physics) says that Ampere's law can be extrapolated to give Biot Savart's law but I'm not sure how to go about it.
 
Physics news on Phys.org
Here is a proof I found because i am too lazy to deal with maths.
Anyway, it is pritty clear they are connected since both deal with the relation beteen I and B

http://www.abbasem.net/articles/axiomatic.pdf

Thumbs up and good luck
 
Last edited by a moderator:
I have not looked at that paper in detail, but it does not claim to derive B-S from Ampere.
What I have read on that website is all wrong. I showed the mistake to the author of the website, but he did not send me the $5,000.

You have to be more specific, "Ampere's law" can refer to two different laws,
"Biot=Savart's law" can be in differential or integral form.
 
I think you can derive the Biot-Savart Law in the form

\textbf{B}(\textbf{x})=\frac{\mu_0}{4\pi}\int\frac{\textbf{J}(\textbf{x}')\times (\textbf{x}-\textbf{x}')}{|\textbf{x}-\textbf{x}'|^3}d^3x'

From Ampere's law (for magnetostatics) in the form \mathbf{\nabla}\times\textbf{B}=\mu_0\textbf{J} and \mathbf{\nabla}\cdot\textbf{B}=0, along with the boundary condition that the field goes to zero at infinity (falls of sufficiently quickly far from the source currents). If that's what you are interested in, I'd start by taking the curl of both sides of Ampere's Law, and then solve the resulting vector form of Poisson's equation for each Cartesian component of \textbf{B} via Fourier Transform methods.
 
Okay I know Ampere's law and Biot Savart's law in their most basic forms so I don't understand the explanation in the previous post. I'm a college freshman so I only know the integral form of Ampere's law also. So how can I derive Biot Savart's law from Ampere's law.
 

Similar threads

  • · Replies 13 ·
Replies
13
Views
2K
Replies
8
Views
1K
  • · Replies 12 ·
Replies
12
Views
4K
  • · Replies 1 ·
Replies
1
Views
6K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 21 ·
Replies
21
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 0 ·
Replies
0
Views
2K