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Differences between two Voltage formulas

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  1. Mar 6, 2015 #1
    What is the differences between these two voltage formulas.
    1. for a point charge: $$V = k\frac{q}{r}$$
    2. for an inductor: $$V(t)= L\frac{di}{dt}$$

    Why are there different voltage formulas? Can second one be derived from the first one?
    Or do they completely represent different concepts?
     
  2. jcsd
  3. Mar 6, 2015 #2

    sophiecentaur

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    The two expressions refer to different circumstances; sub-sets of the general case. If you look at Maxwell's equations then you will see how it all ties together.
    It is common for equations describing phenomena to share a variable.
     
  4. Mar 6, 2015 #3
    Can you please give some hints
     
  5. Mar 6, 2015 #4

    sophiecentaur

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    Just think of the suvat set of equations used for calculations in dynamics. There is always a choice of how to express things in terms of different variables. Are you looking for some extra significance in this?
     
  6. Mar 6, 2015 #5

    Drakkith

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    Well, what is generating the voltage in each case?
     
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