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Electrical potential

  1. Sep 30, 2007 #1

    if you got resistor, having its positive terminal attached to the positive end of a battery (say emf 5V), and the negative end left connected to a simple wire, as such....in short, the circuit is not complete.

    what is the pd when a voltmeter is connected across the resistor?

    is it zero, or 5V??

    and what is the potential, at any point on the wire connected to the negative terminal of the resistor?

  2. jcsd
  3. Sep 30, 2007 #2
    The p.d. is zero. Potentials only make sense relatively. In this case, the potential is the same as the +ve end of the battery.
  4. Sep 30, 2007 #3
  5. Dec 7, 2009 #4
    Ohm's Law: V=IR
    V = voltage across resistor
    I = current through resistor
    Current cannot flow since the circuit is incomplete (Kirchoff's Current Law).
    I = 0,
    regardless of R, V = 0
    The p.d. across the resistor is zero, but the p.d. from the open end of the resistor to the "simple wire" is 5V.
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