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skydog
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Registered: 08/03/05
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Electromagnetics question
#7480041 - 10/03/07 08:25 AM (16 years, 3 months ago) |
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Hey, I'm looking for a little help here.
I'm working this homework problem that asks:
>> Determine which of the following are genuine electric fields.
Then it lists the E fields in question.
Anyway, the text doesn't mention "genuine" electric fields at all, and as far as I can tell, the question is basically asking if the curl of E is equal to 0.
So, I calculated the curl of all the fields and none of them equalled zero. I'm kinda second guessing myself here because I figured at least one would equal zero.
Here is a): E = 5x3Ax + 15x2yAy curl E = 30xyAz
Any help is appreciated
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TheCow
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Re: Electromagnetics question [Re: skydog]
#7480779 - 10/03/07 12:14 PM (16 years, 3 months ago) |
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hm, in my intoxicated state im gona have to ask for more clarificatin about this doohicky. If Iremember correctly, the curl of the electric field is equal tot he negative time derivative of the magnetic flux? Does heonly give you the electric field? You are allowed to have the curl of E not be 0 thats the whole idea of induction. So maybe he wants you check if the gradient of the magnetic field is 0? And it does seem to be 0. But you might want to ignore this as I haven't done straight E&M in about 2 years
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skydog
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Re: Electromagnetics question [Re: TheCow]
#7480834 - 10/03/07 12:24 PM (16 years, 3 months ago) |
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The thing is, we haven't gotten into magnetic fields or induction yet, so it doesn't have anything to do with those.
If curl E = 0, then the vector field is conservative since the line integral is independent of the path of integration.
I'm wondering if the the book is using "genuine" and "conservative" interchangeably, which is kinda strage that they would not make mention of "genuine" anywhere else in the text.
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TheCow
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Re: Electromagnetics question [Re: skydog]
#7480922 - 10/03/07 12:41 PM (16 years, 3 months ago) |
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well in a vacuum the divergence of the electric field is 0. So you could try that, and see what you come up with
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SymmetryGroup8
It's about theFLOW!



Registered: 02/25/07
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Re: Electromagnetics question [Re: TheCow]
#7481103 - 10/03/07 01:30 PM (16 years, 3 months ago) |
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NVM. I have no clue.
-------------------- Be like water my friend!
Edited by SymmetryGroup8 (10/03/07 01:31 PM)
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SymmetryGroup8
It's about theFLOW!



Registered: 02/25/07
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BTW what I had is I remembered something from the vector formulation of Coulmb's laws, where one can show that for E(R), Del X E = 0.
But I need to reread the entire chapter on the equations of electrodynamics...
Now if you wanted to know something about simulation fluid dynamics, I know a little about that.
-------------------- Be like water my friend!
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TheCow
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thats what he was saying. del x E is called the curl of E Also it doesn't equal 0
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skydog
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Re: Electromagnetics question [Re: TheCow]
#7481593 - 10/03/07 04:03 PM (16 years, 3 months ago) |
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I forgot to mention that this is electrostatic.
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SymmetryGroup8
It's about theFLOW!



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Re: Electromagnetics question [Re: skydog]
#7482719 - 10/03/07 08:54 PM (16 years, 3 months ago) |
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Yeah man, I know what a Curl is! I'd fail big time if I didn't. 
I just like writing out Del X E...
I'm sure it's something weird...
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SymmetryGroup8
It's about theFLOW!



Registered: 02/25/07
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Yeah, I just did the given example, and I got what you got.
(30xy)k
Hmmm...
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skydog
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Ah well, it's due tomorrow and I'm gonna hand it in as is. I found the curl of each field, and none of them came to zero, but there is plenty enough work there for some decent partial credit, if nothing else.
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