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Current direction in circuit?

  1. Jul 26, 2014 #1
    I want to know the current direction in the circuit. From where to where it will flow.

    I know the simplification of the circuit. All the three resistor will be in parallel. But without simplification of circuit. I want to know the direction of current.
     

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  3. Jul 26, 2014 #2

    phinds

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    You have enough posts to know better than to ask others to do you work for you. Try it yourself and if you get stuck, come back for help.
     
  4. Jul 26, 2014 #3
    I have tried out. But don't know this is right or wrong.
     

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  5. Jul 26, 2014 #4

    phinds

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    Below the label "R2" you have a current flowing to the right. Below the label "R3" you have a current flowing to the left. These currents are flowing in the same wire. You need to rethink that.
     
  6. Jul 26, 2014 #5
    Here. No current is flowing through resistor R1.
     

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  7. Jul 26, 2014 #6

    phinds

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    If the resistors are all in parallel, as you correctly pointed out they are, how is it possible to have a voltage that drives a current through 2 of the 3 parallel resistors but causes no current to flow in the other?

    Again, you need to rethink things.

    One thing I would suggest is that you get rid of the duplicate labels. I think they are misleading you into somehow thinking that they do not represent the same nodes in the circuit.
     
  8. Jul 26, 2014 #7
    Try redrawing the circuit instead of simplifying it.
     
  9. Jul 26, 2014 #8
    The last picture shows current flowing away from both ends of the battery at the same time.
    Overall, it is very simple to show that since all resistors are in parallel, the current flow is also as simple.
     
  10. Jul 26, 2014 #9
    I know by redrawing the circuit i will get three resistor and current will distribute to each resistor.
    But i want direction of current in this circuit only.

    Here no current would flow through A-R1-B. Because A and C point are directly connected (short circuit ?) Then current will distribute through C to B and C to D.

    Oh yeah,
    I thought,
    Here A & C and B & D are directly connected. Here A & C and B & D points both having same potential .
    So the current will not flow through A to C and B to D.

    This is right or wrong?
     
  11. Jul 27, 2014 #10

    phinds

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    Did you not understand my post #6? Think about it.

    You REALLY need to get rid of the labels B and C. They are meaningless and are just confusing you.

    AGAIN, reread my post #6.
     
  12. Jul 27, 2014 #11

    ehild

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    As U=RI I can be non-zero even in case U=0 if R=0. Current can flow through a zero-resistance wire even if both ends are at the same potential.

    Label on each resistor which terminal is positive (connected to the positive terminal of the battery) and which is negative. The current will flow from + to - through the resistor. Then apply the Node Rule to decide the currents through the shorts.

    ehild
     
  13. Jul 27, 2014 #12

    Zondrina

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    Technically speaking, current has no direction, it is a scalar quantity. It only has a "sense" of direction.
     
  14. Jul 27, 2014 #13
    I have tried but what to do next, i am confusing.
     

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  15. Jul 27, 2014 #14

    Nugatory

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    You know the voltage at each end of R1, so you should be able to find the size and direction of the current across that resistor as well.
     
  16. Jul 28, 2014 #15
    No. I don't know the voltage at each end of R1. How would i get?
     
  17. Jul 28, 2014 #16

    davenn

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    look at your circuit
    note where the ends of R1 are directly connected to

    the voltage of the "thing" they are connected to is labelled :wink:

    ( you work out what the "thing" is that I am referring and you have your answer)



    Dave
     
  18. Jul 28, 2014 #17

    phinds

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    Did you not understand my post #6? Think about it.

    You REALLY need to get rid of the labels B and C. They are meaningless and are just confusing you.

    AGAIN, reread my post #6.

    This is getting old.
     
  19. Jul 28, 2014 #18

    davenn

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    agreed ! :smile:

    also
    You really must learn to simplify a circuit as much as possible. Its going to save you so much confusion for this and future problems.
    Its just one of those thing you have to do. It makes life so much easier :smile:

    so before asking another question. redraw the circuit and post it so we can confirm you are on the right track. THEN the answers to your questions will be clear


    Dave
     
  20. Jul 28, 2014 #19
    Follow the path of least resistance, GrassHopper!
    Each end of each thing connects directly to what other thing ?
    If each end of R1 connects directly to , , , No, not giving the simple answer , , ,
    Your first post declared that the circuit is simply a parallel circuit , , ,
    So why would the currents behave in another manner?
    Advanced level question: "What difference does it make to the circuit, how you draw it?"
     
    Last edited: Jul 28, 2014
  21. Jul 28, 2014 #20

    phinds

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    We've all told him the same things over and over. Beginning to seem like a waste of time.
     
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