Correctness of Equations in Electromagnetism Textbook

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Discussion Overview

The discussion revolves around the correctness of specific equations presented in a Russian handbook for electricians, particularly in the context of electromagnetism. Participants are examining the mathematical validity of these equations and their implications.

Discussion Character

  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant requests a simple confirmation of the mathematical correctness of the equations without sufficient knowledge to evaluate them.
  • Another participant inquires about the source of the equations, identifying it as a Russian handbook for electricians.
  • There is a suggestion that the equations may not be from a previously discussed book, leading to further clarification about the source.
  • Concerns are raised about the equations losing dependence on time after a certain point, which one participant suggests indicates a potential error.
  • A participant proposes a simplification involving taking the amplitude outside the integral, relating it to the Fourier transform of the delta function.
  • Questions are raised regarding the accuracy of the transcription of the equations, particularly about the notation of the amplitude and requests for a visual reference from the textbook.
  • Another participant notes that the notation may obscure the dependence on time, suggesting it complicates the interpretation of the equations.

Areas of Agreement / Disagreement

Participants express uncertainty about the correctness of the equations, with multiple competing views regarding their interpretation and transcription. No consensus is reached on the validity of the equations.

Contextual Notes

There are unresolved questions about the transcription accuracy of the equations, the meaning of certain notations, and the implications of losing time dependence in the expressions.

DesertFox
Hello buddies!
Please, check out these equations...
Tell me, please, are they mathematically correct or not?

I need a simple YES/NO answer.
I have not sufficient knowledge to understand them. I just need to know whether they are correct...

Thank you!

P.S. Am is amplitude; I guess it is a form of Fourier's inverse transform applied in electromagnetism...

CodeCogsEqn (7).gif
 
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What is the source of these equations?
 
Dale said:
What is the source of these equations?
A russian handbook for electricians..
 
Is it this same book that we have discussed here previously?
 
Dale said:
Is it this same book that we have discussed here previously?
No. This one is from Russian source! Is it correct?
 
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After the third equal sign the expression loses its dependence on t, so that seems wrong. The infinity/-infinity is not terribly meaningful either.
 
You can simplify by taking [tex]Ame^{j\psi}[/tex] outside the integral sign.
The resultant integrand looks like the Fourier transform of the delta function.
 
Are you sure you're copying it from the textbook correctly? Shouldn't amplitude ##Am## be with ##m## as a subscript (like in ##A_m## or something)? Can you just screenshot the page with equations (I doubt it is an actual screenshot from the textbook) or make a photo of it?
What is the name of the source and where in the source (page, equation number) one can find these equations?

Dale said:
After the third equal sign the expression loses its dependence on t, so that seems wrong.
Because it got buried in the notation like ##\phi(f)=2\pi f_0 t + \psi## (you can spot it somewhere at the end of this... mess). Not sure if it would help fully decipher it.
 
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