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Op Amp inverting amplifier , help!

  1. Oct 7, 2008 #1

    I dont understand why they did something. I found output voltage to be -1.25v , but to find voltage across the 10k resistor, its (Va-Vo)/10k am i correct? cause when i do this and try to calculate the answer for Io its not right, the book does (Vo-Va)/10k . What am i not understanding ? I did mesh or nodal analysis if i wanted something like this i always took higher potential-lower potential divided by resistor . Or maybe which im not sure, the output is at higher potential then the invertting potential, since its being ampplified. Can someone explain please.

    1. The problem statement, all variables and given/known data

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    3. The attempt at a solution
    Last edited by a moderator: Apr 23, 2017
  2. jcsd
  3. Oct 9, 2008 #2


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    The voltage across the resistor is just the output voltage.
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