A homework in Direct Circuit for beginning students

AI Thread Summary
The discussion revolves around a homework problem in direct circuits where a user seeks help with their solution. They provide their calculations, assuming an ideal ammeter and detailing current values through various circuit components. Other participants encourage the user to explain their steps more clearly and remind them that the forum's purpose is to assist in problem-solving rather than simply providing answers. There is also a mention of a disagreement with the user's younger brother regarding the solution's correctness. The conversation emphasizes the importance of understanding the underlying concepts and verifying calculations in circuit analysis.
fdbjruitoirew
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Homework Statement



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Homework Equations



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The Attempt at a Solution



Well, I am not familiar with the Latex system on this website, just because I am a newbie and I rarely access to this forum. I have a problem (may be simple for you guys) but I still need a solution from you, or at least, please give me the answer if you are boring with typing a lot of formulae.
Thank you in advance
 

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Thanks naspook
I did have the solution that was solved by myself, and I think it's suitable for pupils, not a student but one day, my little brother gave a solution that was different to mine, and he believes that my solution is not right, So I need an answer from you to check.
 
fdbjruitoirew said:
So I need an answer from you to check.

Why don't you give your answer and the steps you took to find your results first in the proper format for this forum.
 
fdbjruitoirew said:
... please give me the answer

You need to read the forum rules. We help folks figure out how to solve problems, we do NOT just "give answers".
 
nsaspook said:
Why don't you give your answer and the steps you took to find your results first in the proper format for this forum.

Yeah, my steps: this DC circuit is a familiar one and we only need to know that with the given assumption as the ammeter is ideal, the potential difference between two points of \ R_5 is zero, then as a consequence \ {I_5}=0A. And \ {I_1}=2A, \ {I_2}=2A,\ {I_3}={I_4}=1A, then from Kirchooff law, \ {I_A}=4A.
Net resistance of the circuit is \ {R_{AB}}=6Ω
 
Yeah, well, you sure take big steps. Especially from I5 to I1, 2,3,4. Perhaps you want to explain the 2,2,1,1 in a little more detail ? And: what did your young brother find ?
 
to BvU:
Well, this problem can be solved simply by re-draw the circuit with the rule as: Consider all points that have the equal potential is one. So we can have a new and simple diagram, from it we get I1, I2, I3, I4, and of course, I5=0 as mentioned above. It's my steps

My little brother: I think he did make a small fault when he re-draw the diagram
 
Still: what did your young brother find ?

I agree with I5. Also with the two 1. But don't you become suspicious at all when 30 V over 6 Ohm gives 4 A ?
 
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  • #10
fdbjruitoirew said:
Yeah, my steps: this DC circuit is a familiar one and we only need to know that with the given assumption as the ammeter is ideal, the potential difference between two points of \ R_5 is zero, then as a consequence \ {I_5}=0A. And \ {I_1}=2A, \ {I_2}=2A,\ {I_3}={I_4}=1A, then from Kirchooff law, \ {I_A}=4A.
Net resistance of the circuit is \ {R_{AB}}=6Ω

Points for trying but you need to review a few things. It's aways good to work backwards (what voltage is across each node with your current calculations) from your result to check for errors.
http://www.usna.edu/Users/cs/vincent/suppnotes/EE301Topic06.pdf
 
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Of course, nasaspook, we should review it, but I did knew this theory many years ago when I was in 9-grade class and I did give my answer.
Could anyone give me your numerical answer, that is all I need
 
  • #12
Could anyone give the answer for me? I need it to check, this problem seems to be simple, but I need the answer from you
 
  • #13
Could anyone give me your numerical answer, that is all I need
Is not the way PF works. You have a choice to ignore answers to questions and hints to improve your work. You can not ask for 'the answer'.
 
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