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Homework Statement
[PLAIN]http://dl.dropbox.com/u/9699560/EE%20Problem.jpg
(I added the text V1, V2, and Voc to the image).
I'm only trying to find Voc because I got the wrong answer. I got Isc correct.
Homework Equations
Basic node voltage analysis techniques.
The Attempt at a Solution
Let the bottom-most node be the ground (reference node).
[itex]\begin{array}{rcl}
\dfrac{v_1}{2} + \dfrac{v_1-v_2}{3} & = & 0 \\
\dfrac{v_2-v_1}{3} + \dfrac{v_2-v_{oc}}{5} & = & 10 \\
\dfrac{v_{oc}-v_2}{5} & = & \dfrac{v_x}{4} \\
v_1 & = & v_x
\end{array}[/itex]
These simplify to:
[itex]\begin{array}{rcl}
5v_1 - 2v_2 + 0v_{oc} & = & 0 \\
-5v_1 + 8v_2 - 3v_{oc} & = & 150 \\
5v_1 + 4v_2 - 4v_{oc} & = & 0
\end{array}[/itex]
in matrix form:
[itex]\left[\begin{array}{rrrr}
5 & -2 & 0 & 0 \\
-5 & 8 & -3 & 150 \\
5 & 4 & -4 & 0
\end{array}\right][/itex]
Solving, this gives:
[itex]\begin{array}{cc}
v_1 & = & 40\, V\\
v_2 & = & 100\, V\\
v_{oc} & = & 150\, V
\end{array}[/itex]
However, 150 V is not the correct answer for Voc. Does anyone know where I have made a mistake?
Thanks!
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