Nodal Analysis Homework

Thread Starter

Jabbar Lawi

Joined Sep 26, 2017
8
Can you please help me on this question with it's solution? Because I really don't have any idea on how I would get the Voltage on a Current Source.

Nodal_Analysis.jpg
 
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WBahn

Joined Mar 31, 2012
30,071
Remember that Nodal Analysis is just a systematic application of KCL, so apply KCL at each node by summing up the currents leaving each node along all the branches connected to that node. For branches connected to an independent current source, that is trivial.

You need to show YOUR best attempt to work the problem to go further.
 

RBR1317

Joined Nov 13, 2010
714
Nodal Analysis is just a procedure. Follow these steps:

1. Identify the nodes.

2. Write the node equation for each node, i.e., The sum of all currents leaving the node equals zero. Current leaving the node is positive. I1+I2+I3+...=0

3. Each term in the node equation begins with the voltage of that node. Each current term has the form:
(Vnode - Vother)/(resistance between node and other node). Current for a current source is as given.

4. Solve the node equations for the node voltages.
 

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Thread Starter

Jabbar Lawi

Joined Sep 26, 2017
8
Ans: V3A = 5.235 V; V7A = 11.47 V. This is the answer base on the book. Please tell me what mistake I've done. Even there a little difference I think there's some mistake on my work. Gonna appreciate your help :)
 

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WBahn

Joined Mar 31, 2012
30,071
Ans: V3A = 5.235 V; V7A = 11.47 V. This is the answer base on the book. Please tell me what mistake I've done. Even there a little difference I think there's some mistake on my work. Gonna appreciate your help :)
You need quite a bit better resolution on that image.

And keep in mind that some of us have older eyes than others.

Make sure YOU can easily read the image. You probably need a file size in the 50 kB to 200 kB range.
 

RBR1317

Joined Nov 13, 2010
714
It is better to assume that all current across the nodes are leaving?
It is better to be consistent in your approach. Look at your equation for "KCL at node V1" and notice that there is a term with no "V1". That seems to be an obvious mistake, and one that you would likely not have made had you followed the procedural steps as previously outlined.
 

Thread Starter

Jabbar Lawi

Joined Sep 26, 2017
8
It is better to be consistent in your approach. Look at your equation for "KCL at node V1" and notice that there is a term with no "V1". That seems to be an obvious mistake, and one that you would likely not have made had you followed the procedural steps as previously outlined.
Thanks sir. I got the answer now.
 
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