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Homework Help: AC analysis query

  1. Apr 12, 2010 #1
    1. The problem statement, all variables and given/known data
    I have two questions to two different problems.
    The first:
    dcsepf.jpg
    3. The attempt at a solution
    My attempt:
    ddeuk8.jpg

    Thing is, the solutions have V2=4.986[tex]\angle[/tex]111.45(degrees) and i can't seem to get to that answer at all? What is wrong with my attempt because i can't see anything wrong with it? (Unless i've left out some negative signs, but even then it shouldn't change by much? Btw i took a supernode at the two nodes, hence my long KCL eqn.)

    My second question is:
    ot3xc0.jpg

    Attempt:
    n6atk1.jpg

    So to find the current through the resistor, i need to firstly find the node voltages V1 and V2 right? Then it's just a simple matter of (V1-V2)/5+j15. Thing is, i'm having a difficult time trying to find V1 or V2, since as you can tell my maths gets rather messy and i just hit a wall with V1=... + V2(...). Can someone point me in the right direction? Also, i suspect that this is the 'right way' to do it, because according to the solutions, V1=6.735[tex]\angle[/tex]-38.54(degrees) and V2=16.25[tex]\angle[/tex]-55.52(degrees), and when i substitute in V2 into V1=...+V2(...) i get the answer of V1..so how do i actually find V1 or V2?

    Thanks.
     
  2. jcsd
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