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Electronics, a resistor Cube

  1. May 10, 2005 #1
    Imagine a cube where all sides have a resistor, now remove one resistor from it and replace it with an ohmmeter, the ohmmeter reads 100ohms, calculate the resistance of each resistor. By the way each resistor is the same value.

    How do you go about doign this question?
  2. jcsd
  3. May 10, 2005 #2
    Questions like this only have one purpose: to confuse you. There is a very simple, sure-fire way of solving problems like this, and that is to re-draw the schematic in a way that makes sense. "Unwrap" the cube and draw it as a 2d schematic, and you will see that it's a trivial problem that can be solved with mesh analysis or KCL/KVL.

    Edit: don't be afraid to rearrange the circuit's shape a bit, too, to make it easier to evaluate. As long as you keep the connections at the same points, the outcome will be identical.
  4. May 12, 2005 #3
    Can you give me an image of your cude because i nedd an illutration to answer this question
  5. May 12, 2005 #4
    I want an image of your cube if it's possible
  6. May 13, 2005 #5


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    OK here ya go. It even has the revised version for flatlanders :smile:

    Attached Files:

  7. May 13, 2005 #6
    There's a better way to draw a flat "resistor cube" that doesn't involve overlapping any wires.


    In these circuit diagram problems it always helps me to imagine the wires as these infinitely stretchy/bendable entities that just have to stay connected. Bend them around in my head a bit, then see what I can come up with.
  8. May 14, 2005 #7


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    I think you are right. It just looks too 3D that way for my tastes :smile: , like peering into the cube through the face. I actually prefer the 3D look. The important thing is that no matter how you draw it, you have to see the six loops and deal with them.
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