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Circuit theoryplease help thanks!

  1. Sep 17, 2007 #1
    1. The problem statement, all variables and given/known data

    I have attached the circuit diagram to this post. I have to find i which I have shown in the diagram. All the voltage and resistor values are also given.

    2. Relevant equations



    3. The attempt at a solution

    I tried finding the current for the whole circuit which would be 36/4= 9A but I am not sure that is right. I think I missed something.
     

    Attached Files:

  2. jcsd
  3. Sep 17, 2007 #2

    berkeman

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    Staff: Mentor

    The diagram is incorrect. Since it is a series circuit, the current is the same through all three components. So you cannot have a current source of 5i, in series with a current i.

    Could you please check the original circuit? After you check the circuit schematic again and fix up the diagram, tell us what equations you think you should use to solve for the values in the circuit.

    Welcome to the PF, BTW.
     
  4. Sep 17, 2007 #3
    Sorry about that, i put the value of the resistance (4ohms) on the diagram. As I said, what I did was use V=IR and calculate i as follows

    I= V/R= 36/4= 9A.

    Problem is, I am not sure it is this simple.
     

    Attached Files:

  5. Sep 18, 2007 #4

    berkeman

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    Staff: Mentor

    What is the thing on the right? Is it a current-dependent voltage source? If so, you need to write the sum of the voltage drops around the circuit, and set the total sum equal to, what?
     
  6. Sep 18, 2007 #5
    i dunno what it is which is why this question is here. apparently, you ask more questions than me lol. if u can help me out, please do!
     
  7. Sep 18, 2007 #6
    so basically its just (v-36)/4 ???
     
  8. Sep 18, 2007 #7
    (v-36)/4= 0??
     
  9. Sep 18, 2007 #8

    berkeman

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    Staff: Mentor

    I'm honestly not able help without a clearer problem statement. Would it be possible for you to scan the question and post that?
     
  10. Sep 18, 2007 #9
    I dunno whether I can scan it because it might end up being higher than the upload limit. But the question says Find i for the circuit. There is a 36V on the left and a current dependent voltage source on the right which says 5i. There is a 4 ohm resistor as shown on the diagram. There is also i shown on the diagram with the arrow pointing from left to right. It is a 3 mark question.

    I first tried to use V=IR in thinking that i next to the arrow means the initial current which would be I=V/R=36/4= 9A but i think im wrong
     
  11. Sep 18, 2007 #10
    The second, corrected diagram has no more mistakes btw so u can refer to that
     
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