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Voltage/Potential Difference

  1. Mar 7, 2010 #1


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    Why is voltage also called potential difference? And what is the 'push' on the electrons, and how can this be calculated?

  2. jcsd
  3. Mar 7, 2010 #2
    The terms met with in electricity have some historical bias. Voltage appears to come from the name of the scientist Alessandro Giuseppe Antonio Anastasio Volta who was one of the first people to investigate electric circuits (http://en.wikipedia.org/wiki/Alessandro_Volta)

    One way to introduce the linke between voltage and currents in an electric circuit is to make an analogy between water flowing in a pipe (a "fluid circuit").

    The rate at which electric charge (or current) moves around a circuit depends in part on the "electrical pressure" provided by a battery. In fact, it is the "difference in electrical pressure" that is applied to the two ends of the circuit that is important.

    People usually say objects move because there is a force acting on them. In fact, it is probably more accurate to say is the difference in forces that make objects move.

    To get to p.d. make the following steps:
    1) "difference in electrical pressure" -> "difference in electrical potential"
    2) "difference in electrical potential" -> "electrical potential difference"
    3) "electrical potential difference" -> "potential difference"

    There is possibly a historical reason why "electrical pressure" becomes "electrical potential".

    Electric charge moves (i.e. an electric current flows) because of differences in the electrical forces acting on it. I usually try to say a current flows through a component because there is a difference in electrical potential on the two sides of the component, i.e. a current flows because of a p.d.
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