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Find the Current Flowing through each resistor

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  1. Mar 27, 2017 #1
    1. The problem statement, all variables and given/known data
    upload_2017-3-27_18-32-38.png

    2. Relevant equations / 3. The attempt at a solution
    Looking to solve mistakes to study from homework. Here's what I had so far

    upload_2017-3-27_18-32-1.png
     
  2. jcsd
  3. Mar 27, 2017 #2

    BvU

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    Good. Now: what is your question ?
     
  4. Mar 27, 2017 #3
    The batteries are arranged in opposite polarity. Check your second equation.
     
  5. Mar 28, 2017 #4
    I'm just wondering how to find the Voltage drop.
    Would I need to find the voltage using V=IR for each of the currents that I found and then I could observe the drop from V1 to V2?
     
  6. Mar 28, 2017 #5

    BvU

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    IS it clear what you mean with V1 and V2 ? What do you think of Magoo's remark ?
     
  7. Mar 28, 2017 #6
    Aren't the currents going in the same direction, though? - They're both moving in a clock-wise direction?
     
  8. Mar 28, 2017 #7

    BvU

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    Yes, so do the voltage drop over the 2 k##\Omega## and the 5V have he same sign or an opposite sign ?
     
  9. Mar 28, 2017 #8
    Hmm...If you start with 10V and on the opposite side is 5V, is it bc of Kirchhoff's voltage law that the voltage drop would be negative over the 2kOhm to 5V battery?
    Because your overall voltage of the loop should end up =0?
     
  10. Mar 28, 2017 #9

    cnh1995

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    Sum of potential changes (gains and drops) should be zero.

    Usually, you can't predict that. You should assume the directions of currents first and solve the KVL and KCL equations. If the current direction assumed is incorrect, you'll get a minus sign in the answer.
     
  11. Mar 28, 2017 #10
    A few things:

    Voltage polarity is due to potential difference.

    Your equations don't seem to be loop (mesh) equations.

    The direction to assign a current for analysis is arbitrary, as long as you don't swap it's direction mid analysis. If you guessed the correct direction, the result will be positive. Otherwise, the result will be negative. Compare your result, to the direction you assigned, and that will tell you which way current is flowing.
     
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