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Dynamic resistance confusion

  1. Mar 30, 2009 #1


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    I'm confused about dynamic resistance.

    The definition I've seen is Rd = dV/dI.

    Is it also ok to write it Rd = d(IR)/dI, so that Rd = R + I dR/dI ?

    I couldn't find a straightforward definition for dynamic resistivity at all …

    is it ρd = d(Iρ)dI = ρ + I dρ/dI ?
  2. jcsd
  3. Mar 30, 2009 #2
    Dynamic resistance is dV / dI. It is often used to refer to the dynamic forward resistance of a diode junction, or the dynamic resistance of a zener diode junction.
  4. Mar 30, 2009 #3
  5. Mar 30, 2009 #4


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    If RD = dV/dI, then a reasonable definition for dynamic resistivity would be
    ρD = dE/dJ,​

    where E is electric field and J is the current density.
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