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Simplifying circuit

  1. Dec 5, 2016 #1
    [ Mod Note: relocated to homework forum so template is missing ]

    Hi
    Iwas soving a problem and the question is to simplify the circuit . Ididnt understand how the whole circuit is the same as the sum of I1 and I2 and U1 (which is a voltage source ) and I3 and R1 dont play a role
    Thank you





    upload_2016-12-6_1-23-41.png
     
    Last edited by a moderator: Dec 5, 2016
  2. jcsd
  3. Dec 5, 2016 #2

    NascentOxygen

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    Staff: Mentor

    This is similar to some of our homework questions, so I'll move this to the homework forum.

    Imagine there is an external load, represented by an additional resistor R (not shown) between A and B.

    Looking at these sources (and their ghastly non-standard symbols) can you say how much current is leaving this circuit to flow into resistor R via the wire at A?
     
  4. Dec 6, 2016 #3
    true its equal to i1 + i2
     
  5. Dec 6, 2016 #4
    But I have a problem where its not clear
     

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  6. Dec 6, 2016 #5

    NascentOxygen

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    [We're not finished yet.]

    So that's the current leaving at A and going into the top of the load resistor, R.

    Next, what would be an expression for current leaving the lower end of R to reenter the circuit at point B?
     
  7. Dec 6, 2016 #6

    NascentOxygen

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    What things have you explored in simplifying this next arrangement?

    3-png.109993.png
     
  8. Dec 6, 2016 #7

    CWatters

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    Have you studied Kirchhoff's Current Law?
     
  9. Dec 6, 2016 #8
    also I1 +I2
     
  10. Dec 6, 2016 #9

    NascentOxygen

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    So what is the voltage across the load resistor, R?

    Now, as a learning exercise, deduce what must be the voltage across the top left current source (the source supplying I1 ).
     
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