A load is located 100 feet from the source. If #10 copper wire supplies the load, the total resistance of the wire between the source and the load will be ? #10 copper wire at 1,000 feet is 1.21 ohms. My answer is .121 ohms. But, I was told that was incorrect.

  • 1
    Yes it is incorrect. – Brian Drummond Aug 7 '16 at 15:23
  • 4
    Draw the diagram of the battery, the wire and the load. Then work it out again. – Transistor Aug 7 '16 at 15:28
  • To clarify, your math isn't wrong, but your visualization of the problem is. – Ignacio Vazquez-Abrams Aug 7 '16 at 15:29
  • Remember, a circuit is a closed loop. Sketching the circuit will likely help. Look at everywhere the #10 wire is required in the circuit. – user2943160 Aug 7 '16 at 15:41
  • @DanielTork, all of the people who commented before you already know that. Since this is school work, they are trying to lead the OP to the answer without just spelling it out. We generally try to help people with school work, but avoid just coming out and telling them. Not a big deal. Just FYI. ;-) – mkeith Aug 8 '16 at 3:49

Thank you all. It appears that I have not included the return wire to complete the circuit. This problem was for a DC circuit, and all I was picturing in my mind was the typical light for an automobile with only one lead coming off it, using the chassis as the ground. I am going with .242 ohms to include the return path.

  • A 100' long chassis would be unusual. – Transistor Aug 8 '16 at 18:05

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