The way of evaluating the electric field

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Discussion Overview

The discussion revolves around evaluating the electric field using a specific formula presented by a participant. The scope includes theoretical and mathematical reasoning, with references to Gauss's Law and Coulomb's Law.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant requests help with a problem related to evaluating the electric field, mentioning a formula in a file they uploaded.
  • Another participant suggests that examples of Gauss's Law might be what the original poster is looking for.
  • Several participants express a preference for direct questions in the forum rather than links to external files, citing security concerns.
  • A participant notes that the method described by the original poster is difficult to understand, particularly regarding the meanings of R and the vector dS.
  • One participant recalls that the equation mentioned involves an integral over a closed surface, which aligns with Gauss's Law in integral form, questioning if this is what the original poster intended.
  • Another participant points out a potential mistake in the original poster's derivation, questioning the treatment of charge density and its integration over a surface.
  • There is a suggestion to use Gauss's Law as a more straightforward approach to evaluating the electric field.

Areas of Agreement / Disagreement

Participants express differing views on the method of evaluating the electric field, with some advocating for Gauss's Law while others challenge the original poster's approach. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Participants highlight potential misunderstandings regarding the integration of charge density and the application of vector calculus in the context of electric fields. There are also concerns about the clarity of the original poster's formula and its implications.

abcdefg10645
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I upload the file which I described my problem thoroughly , I need someone who can help me to solve the problem.


Thanks!
 

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You want examples on how to use Gauss's Law?

Zz.
 
I think you will get more replies if you paste your question directly into your post in the forum - at least I don't like to open Word docs from sources I don't know. If you have pictures, you can upload them as attachments, and they will be shown directly in the post (if I recall correctly...).
 
Mårten said:
I think you will get more replies if you paste your question directly into your post in the forum - at least I don't like to open Word docs from sources I don't know. If you have pictures, you can upload them as attachments, and they will be shown directly in the post (if I recall correctly...).


In fact , I need someone to display evaluating electric field by using the formula I wrote in the file .

Gauss`s law is quite convenient to reckon the electric field , but the method I mention is quite...difficult to understand the meanings of R and[tex]\vec{}dS[/tex] .

And , I am sorry that I did not post the image but doc , for the image file is too "massive" to upload ...

Do not worry about that there exists virus .

I am sure that is thoroughly "pure"

Thanks for your replying (I hope you can give me the perfect answer to this question!)

:smile:
 
ZapperZ said:
You want examples on how to use Gauss's Law?

Zz.

In fact , I need someone to display evaluating electric field by using the formula I wrote in the file .

Gauss`s law is quite convenient to reckon the electric field , but the method I mention is quite...difficult to understand the meanings of R and[tex]\vec{}dS[/tex] .
 
abcdefg10645 said:
In fact , I need someone to display evaluating electric field by using the formula I wrote in the file .

Gauss`s law is quite convenient to reckon the electric field , but the method I mention is quite...difficult to understand the meanings of R and[tex]\vec{}dS[/tex] .

You removed the file?

As far as I can recall, the equation had an integral over a closed surface of a dot product of E and unit vector "n". This is exactly Gauss's law in the integral form, which should be nothing new to you if you are at the level of doing vector calculus form in your E&M class. That's why I had to double check if this is what you were asking.

Zz.
 
You have written Coulomb's law for the electric field. Examples of its use are in every elementary physics text.
 
I think there is a mistake in your derivation. How does the the charge density (rho) go "inside" the del operator?
Del(rho/R) is not equal to rho*del(1/R). rho is a function of R. (If by rho you mean the charge density).
And also, in the last integral you have rho*dS... rho is a volume density. How do you integrate it over the surface? And from the point of view of physics, the field depends not only on the charge on the surface.. it cannot be right.

As they said above, use Gauss' law.
 

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