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Coulomb's Law (positive & negative charges)

  1. Mar 18, 2007 #1
    I need to draw a single point charge with a magnitude of +4.3 C (coulomb's)

    I want to make sure that I am doing this right so:

    If one electron equals 1.602*10^-19 C than +4.3 C is actually a negative charge and therefore -4.3 C would be a positive charge.

    Is this right or do i have it backwards and by stating +4.3 C they mean a proton charge (positive charge)?
  2. jcsd
  3. Mar 18, 2007 #2

    Doc Al

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    Staff: Mentor

    You have it backwards. 1.602*10^-19 C is the magnitude of the charge on the electron (or proton). The sign of an electron's charge is negative.

    A charge of +4.3 C is a positive charge--just as you'd expect!
  4. Mar 18, 2007 #3


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    Staff Emeritus
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    No, one electron has a charge equal to -1.602x10-19 C. However, the elementary charge, which is assigned the symbol e has a charge equal to +1.602x10-19 C. Therefore, a proton has a charge of +1e and an electron of -1e. Does that make sense?

    Edit: Doc Al strikes again...
  5. Mar 18, 2007 #4
    Yes, thanks
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