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Voltage across a wire

  1. Feb 22, 2010 #1
    1. The problem statement, all variables and given/known data
    Why are voltages across wire close to zero? Or is it just a coincidence?



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Feb 22, 2010 #2

    PhanthomJay

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    Do you mean why is the voltage difference between 2 near points along an energized wire near 0?? Or do you mean why is the voltage difference between 2 wires each energized at near the same voltage and phase angle near 0? or something else? Please indicate your thoughts on this.
     
  4. Feb 22, 2010 #3
    In class we used a voltmeter to measure the voltage across the different parts of a circuit. In the circuit there was a battery, resistor and light bulb. they just had us measure in parallel using the voltmeter all the parts including the wire. One of our questions afterwards was why are some of the voltages near zero?
     
  5. Feb 22, 2010 #4

    collinsmark

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    May I assume that at some point in the exercise you were able to either measure the current going through the wires, or deduce the current going through the wires in some other way? You might want to invoke Ohms' law in your answer, noting that the resistance of a typical wire is quite small.
     
  6. Feb 22, 2010 #5

    PhanthomJay

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    The resistance of the wire (ohms/meter) is rather low, so there is very little votage drop between 2 points on the wire. If the wire was very long, or very small, the resistance would be greater, and then there could be a measurable voltage drop between the 2 points.
     
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