Nodal analysis - w/ dependent current source

Thread Starter

castrogfx

Joined Apr 13, 2012
4
Hi,
I think this problem is easy, but I can't do it.


answer: 2 A

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Node A is on the left, node B is on the right.

So,
A) \[ i_2 + i_4 = i_1 + i_3 \]
B) \[ i_3 + i_7 = i_6 + i_5 \]

\[i_1=\frac{v_1}{5}\], \[i_2=-3A\], \[i_3=\frac{v_1 - v_2}{20}\], \[i_4 = i_5 = 3 i_1 = \frac{3 v_1}{5}\], \[i_6=\frac{v_2}{10}\], \[i_7= 10 A\]

A) \[ -3 + \frac{3 v_1}{5} = \frac{v_1}{5} + \frac{v_1 - v_2}{20}\]

B) \[\frac{v_1 - v_2}{20} + 10 = \frac{v_2}{10} + \frac{3 v_1}{5}\]


I have this system of linear equations:

\[-60 = -7v_1 - v_2\]
\[200 = 13v_1 + 3v_2\]

\[v_1 = -2.5 V
v_2 = 77.5 V \]


\[i_1 =\frac{-2.5}{5} = -.5 A\]

Thanks for the help!
 

t_n_k

Joined Mar 6, 2009
5,448
The dependent source seems to be a CCVS despite having a symbol typical of a CCCS. However the answer of 2A is correct if it is a CCCS. I note you have I7 as 10A. Do you now see the error?
 
Last edited:

Thread Starter

castrogfx

Joined Apr 13, 2012
4
I've tried this so many times that I copied wrong in a moment.
Unbelievable.
Thanks t_n_k for the help, I really appreciated it.
 
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