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Homework Help: Really Hard Circuit Question

  1. Apr 13, 2005 #1
    Hello there!!!

    I am doing a really tough physics question on circuits. I am posting link to the picture of the circuit so you can actually see what is going on :smile:

    These are the questions:

    a) What is the current through R1?

    This one was easy I just found the total resistance of the circuit and used the equation V= IR to get a current of 2.4 A which is the answer/

    b) What is the current through R4?

    I have no clue how to do this one, no matter what I do I get an answer either to high to to low. The answer should be 0.8 A.

    c) What is the power dissipated in R2?

    I have a feeling that I can't get this one because I can't get the one before it. The answer should be 5.1W.

    d) What is the total power dissipated in the circuit?

    I could do this one. It's just p = iv (12.0V)(2.4A) = 29W

    Oh and one more really stupid thing. When you are drawing a graph and it says to plot resistance as a function of the cross-sectional area the resistance should go on the x-axis right? :redface:
  2. jcsd
  3. Apr 13, 2005 #2


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    Homework Helper

    you've forgot the link
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