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Homework Help: Questions regarding DC circuits

  1. May 8, 2008 #1
    I have one confusing issue to resolve:

    What is the resistance between points [tex]A[/tex] and [tex]B[/tex] in simple system illustrated in attachment?Wouldn`t be logical to assume that it is [tex]0[/tex],as current strives to flow through path with lowest possible resistance,if I understood it correctly?

    Yes,I know that real transmission lines have some resistance,but in network anaylsis their resistance is considered to be equal to zero.
     

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    Last edited: May 8, 2008
  2. jcsd
  3. May 8, 2008 #2

    stewartcs

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    You have a short circuit so what ever the resistance of the wire connecting point A and B.

    CS
     
  4. May 12, 2008 #3
    Yeah, it's zero assuming everything's ideal. Mathematically even, you have a wire ([tex]R=0[/tex]) in parallel with a resistor ([tex]R=R_0[/tex]). Then the parallel combination is:

    [tex]R_{eq} = \frac{1}{ \frac{1}{0} + \frac{1}{R_0} } = \frac{1}{\infty + \frac{1}{R_0}} = 0[/tex]

    I should probably have put some limits in there to be mathematically correct, but you get the idea.
     
  5. May 12, 2008 #4
    Thanks to both of you!
     
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