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Homework Help: Please determine the directions of currents

  1. Oct 14, 2012 #1
    1. The problem statement, all variables and given/known data
    What is the current in the 18 Ohm resistor in the figure below? What is the current in the 12 Ohm resistor? Please determine the directions of currents as well. What is the power dissipated in the 4.5 Ohm resistor? What is the equivalent resistance of the circuit shown (meaning between points A and B?

    My only question is the one in the title, that I have put in bold. The rest I am fair fairly confident of.

    The drawing:

    2. Relevant equations

    I can't really find much information about the whole matter. Any pointers to the right direction (no pun intended) would be awesome! The only thing I found so far is that current flows through all resistance (obviously) it won't simply opt for the path with the least resistance. I also know that current flows from positive to negative. Would the answer simply be:

    Current leaves the positive portion of the battery (longer line), travels along the top line, splits in two at the junction.

    1) First part keeps going left, goes down, and when it meets the bottom junction it keeps going straight until it reaches the negative part of the battery
    2) Goes down at the top junction, then splits in two at the diagonal junction until it hits the bottom line, then goes to the right towards the negative part of the battery


    Attached Files:

  2. jcsd
  3. Oct 15, 2012 #2
    Anyone got any clue? My deadline to submit is today :(
  4. Oct 15, 2012 #3


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    Staff: Mentor

    You are correct in stating that conventional current flows from higher potential to lower potential. Your summary of the resulting current directions looks fine.
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