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Finding the number of electrons?

  1. Aug 2, 2017 #1
    1. The problem statement, all variables and given/known data
    I was asked to find number of electrons passing through a wire giving only resistance.

    2. Relevant equations
    V=IR
    I = dQ/dt
    n= Q/e

    3. The attempt at a solution
    It's pretty straight forward, with direct substitution of the equations with the written order.
    I could attempt this assuming V = 1 V but, is there another way to get this with only the value of R and I'm not seeing it??
     
  2. jcsd
  3. Aug 2, 2017 #2
    Do note that you also have to assume the time (t) as well as the voltage.
    Therefore I believe the values of V and Time(t) don't matter so long as they have a relationship such that V times Time t gives you 1, given the relationship they have in the derived equation.
     
  4. Aug 2, 2017 #3
    forgot to mention that he did mention it's number of electrons passing through xx ohms in one second.

    Correct me if wrong, your suggestion is:
    n=Q/e=Idt/e= (V/R)dt/e=(V/dt) R/e and assuming V/dt = 1 but I'm not how does that work if I look at it dimensionally using units.
     
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