# Analyzing Circuit Nodes & Meshes: Find I'”

• gfd43tg
In summary, the conversation discusses a circuit with 8 extraordinary nodes and the question of how many independent meshes and mesh currents can be determined from the circuit. There is some debate over the definition of an extraordinary node and its relation to essential nodes. However, it is agreed upon that the right-most mesh in the circuit cannot be determined by inspection due to the presence of a shared branch.
gfd43tg
Gold Member

## Homework Statement

Consider the circuit shown below.
(a) How many extraordinary nodes does it have?
(b) How many independent meshes does it have?
(c) The values of how many of those mesh currents can be determined immediately from the circuit?
(d) Apply mesh analysis to find I’.

## The Attempt at a Solution

I am having a hard time for parts (a) and (b). I put a dot on everything I called an extraordinary node, and got 5. My friend got 10 and I don't see it.

Also, the the independent meshes, apparently where the 7 Amp current source is, you can't say the furthest right branches mesh current by inspection. How is this?

#### Attachments

• 3.1.png
23.4 KB · Views: 439
• 3.1 attempt 1.pdf
181.7 KB · Views: 249
What is the definition of an extraordiary node?

Where 3 or more junctions meet

Maylis said:
Where 3 or more junctions meet
That is too ambiguous, too imprecise. What is the formal definition from your course notes?

Maylis said:
Also, the the independent meshes, apparently where the 7 Amp current source is, you can't say the furthest right branches mesh current by inspection. How is this?
You were probably told that so as to contrast it with most of the other meshes in this figure. Most meshes here show a current source in one of their unshared branches, and this current sets that mesh's mesh current. The right-most mesh has a current source but located in a shared branch, so that source represents the nett result of two mesh currents, not one current alone.

To say that the mesh current there can't be determined by inpection is arguable, though.

Last edited:
Given in lecture slide:

Extraordinary
Node:
connection point between at least 3 branches

I watched a youtube video, and now after watching it

I count 8 extraordinary nodes. Anyone else get the same?

Last edited by a moderator:
Maylis said:
I count 8 extraordinary nodes. Anyone else get the same?
8 is the number I count.

Okay great, I feel more comfortable with it now. Thanks

## What is the purpose of analyzing circuit nodes and meshes?

The purpose of analyzing circuit nodes and meshes is to determine the currents and voltages at different points in a circuit. This information is crucial in understanding how a circuit functions and can help in troubleshooting and designing circuits.

## What is a circuit node?

A circuit node is a point in a circuit where two or more circuit elements are connected. It is represented by a dot in a circuit diagram. The voltage at a node is the same for all elements connected to that node.

## What is a circuit mesh?

A circuit mesh is a loop formed by a continuous path of circuit elements. It can be thought of as a closed path in which the current flows. The voltage drop across each element in a mesh adds up to zero according to Kirchhoff's voltage law.

## How do you find the current through a circuit node?

To find the current through a circuit node, you can use Kirchhoff's current law. This law states that the sum of all currents entering a node is equal to the sum of all currents leaving that node. By setting up equations for all the currents at the node, you can solve for the unknown current.

## How do you find the current through a circuit mesh?

To find the current through a circuit mesh, you can use Kirchhoff's voltage law. This law states that the sum of all voltage drops around a closed loop is equal to the sum of all voltage sources in that loop. By setting up equations for the voltage drops and sources in the mesh, you can solve for the unknown current.

Replies
5
Views
1K
Replies
15
Views
3K
Replies
10
Views
2K
Replies
7
Views
2K
Replies
2
Views
1K
Replies
6
Views
2K
Replies
5
Views
2K
Replies
1
Views
2K
Replies
6
Views
3K
Replies
5
Views
2K