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Circuit Analysis Help

  1. Sep 3, 2011 #1
    [a]1. The problem statement, all variables and given/known data[/b]
    I have the following circuit attached as PDF and I need to find out if the state of the diode and what V0 is. The forward voltage on the diode is 1V.

    [a]3. The attempt at a solution[/b]
    I just simply used current division to know that the diode is on since 1V travels up to the diode and 1V through the 1KΩ resistor. But at V0 what do I do? I would stupidly say it's zero since it's an open circuit but I am way to new at this.

    Attached Files:

    • 4.pdf
      File size:
      159.5 KB
  2. jcsd
  3. Sep 3, 2011 #2


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    Gold Member

    Some comments on your terminology:
    Voltage is always applied or measured across something (or at a point with respect to some other reference point). Current always travels through something.

    If you look at the voltage across the diode, the diode will be on if the voltage at the anode is greater than the voltage at the cathode (bar side). So look at the 1K resistor in parallel. If current is going through it from left to right, the voltage on the left will be greater than the voltage on the right.

    You are not so stupid if you think you might be wrong :wink:. V0 is simply the same voltage as the voltage across the resistor.
  4. Sep 5, 2011 #3


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    Staff: Mentor

    Assume that the diode is not conducting any current. Determine what Vo would be.

    Under these circumstances, determine what the forward voltage across the diode terminals would be. Is this greater than 0.7 volts? If not, then your initial assumption is correct, i.e., the diode is not conducting.
    Last edited: Sep 5, 2011
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