How to analyze a circuit with one node using the node method

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SUMMARY

The discussion focuses on analyzing a circuit with a single node using the inspection method. The resistance matrix, A, is defined as [17000], with the voltage matrix, x, representing the node voltage, and the current matrix, M, calculated as [2mA]. However, the correct approach requires using the conductance matrix instead of the resistance matrix, and the current sources should be noted as 1 Amp each rather than 1 milliamp. The participant realizes their mistake regarding the current source values and the appropriate matrix for nodal analysis.

PREREQUISITES
  • Understanding of nodal analysis in electrical circuits
  • Familiarity with resistance and conductance matrices
  • Knowledge of current source values and their impact on circuit analysis
  • Proficiency in matrix operations, including inversion and multiplication
NEXT STEPS
  • Study the concept of conductance matrices in nodal analysis
  • Learn how to perform matrix inversion and multiplication in circuit analysis
  • Explore examples of circuits with multiple nodes using the inspection method
  • Review the principles of current sources and their representation in circuit equations
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Electrical engineering students, circuit designers, and anyone interested in mastering nodal analysis techniques for circuit evaluation.

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Homework Statement


I have the circuit given below with a single node where R3 and ground meet. How can I solve this problem using the inspection method? Is it possible? I can easily solve using another method but I would rather try using the inspection method.

Homework Equations



Ax = M
A is the resistance matrix obtained via inspections
x is the voltage matrix
M is the current matrix

The Attempt at a Solution



Since there is only one node then my resistance matrix, obtained using inspection, will only have one row and one column. Thus in this case:

A = [ 17000]

The voltage matrix will only have my one at the node:

x = [V]

finally the current matrix will have the sum of all the current sources going into the node (subtract those going away):

M = [1mA + 1mA] = [2mA]

I can take the inverse of A and then multiply it by M to get:

x = A^-1 * M
or
V = 2mA/17000
which i believe is the wrong answer. Am I wrong? Can I even solve this using inspection since it is only one node? Thanks.
circuitNode.png
 

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Since this is nodal analysis you'll want the conductance matrix, not the resistance matrix. Those current sources appear to be 1 Amp each, not one milliamp each.
 
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gneill said:
Since this is nodal analysis you'll want the conductance matrix, not the resistance matrix. Those current sources appear to be 1 Amp each, not one milliamp each.
OMG I totally forgot about that! Thank you Thank you!
 

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