Deriving Electric Field Near Metal Plate: Coulomb's & Gauss' Law

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Homework Help Overview

The discussion revolves around deriving the electric field near a square metal plate with infinitesimal thickness, specifically using Coulomb's law and Gauss' law. The original poster presents a formula for the electric field in terms of charge per unit area and relative permeability, seeking assistance in deriving this result.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss various approaches to derive the electric field, including using Coulomb's law and Gauss' law. There are questions about the initial steps and the correct application of these laws, with some participants expressing confusion over the results obtained.

Discussion Status

The conversation is ongoing, with participants exploring different methods and questioning the assumptions behind their calculations. Some guidance has been offered regarding the use of Gaussian surfaces and the integration process, but there is no clear consensus on the correct approach or outcome yet.

Contextual Notes

Participants are working under the constraints of deriving the electric field without providing complete solutions, and there is a focus on understanding the implications of using different laws in the context of an infinitesimally thick metal plate.

j-lee00
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What is the field near a square metal plate (with infinitesimal thickness)

The answer is E = [tex]\sigma[/tex] / [tex]\epsilon[/tex]

where [tex]\sigma[/tex] = Charge per unit area

[tex]\epsilon[/tex] = relative permeabily

Please help me to derive this result. using coulombs and then gauss' law
 
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What will be the first step?
 
For coulomb

[tex]\int[/tex] dE = k [tex]\sigma[/tex][tex]\int[/tex] 1/r^2 dA

Im getting

E = [tex]\sigma[/tex] [tex]\pi[/tex] / 8 [tex]\epsilon[/tex]

The symbolys are multiplying not tothe power of. This result is wrong
 
I didn't understand how did u get that answer.
newayz, try using gauss theorem... what is the Gaussian surface here?
 
no i want to use colomb
 
K, then you have take a disc with infinitesimal width, find electric field due to it, and integrate for radius = 0 to infinity(coz the sheet is infinite)
 
i know
 
im just not getting the right ans
 
k, tell me what is electric field at a distance x from the infinitesimally wide disc of radius r ?
 

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