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Resistance of a wire

  1. Feb 27, 2012 #1
    1. The problem statement, all variables and given/known data


    Suppose that a 32-meter length of resistive wire is connected across the terminals of a battery. If a voltmeter reads 21 V when connected across the battery terminals, what should it read when connected across a 18-meter section of the wire? Enter you answers using one decimal place, do not enter units.



    2. Relevant equations

    e = iR


    3. The attempt at a solution

    thought the voltage doesn't change.
    but I think its wrong. Please help?
     
  2. jcsd
  3. Feb 27, 2012 #2

    SammyS

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    Hello john216. Welcome to PF !

    Think of this as 32 one-meter lengths of wire connected in series.

    What is the voltage drop across any one of those one-meter wires ?

    How much across 18 of them ?
     
  4. Feb 27, 2012 #3
    could you clarify little?
    i'm confused
     
  5. Feb 28, 2012 #4

    SammyS

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    It's hard for me to know what part/parts of what I posted confuses you.

    What do you understand about series circuits and resistances in series?

    What do you understand about voltage drop and Ohm's Law?

    etc.
     
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