KCL Question: Determine Currents

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Discussion Overview

The discussion revolves around determining the currents in each branch of a circuit using Kirchhoff's Current Law (KCL) and other circuit analysis techniques. Participants explore various methods, including KCL, mesh analysis, and nodal analysis, to solve the problem presented in a homework context.

Discussion Character

  • Homework-related
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant presents initial calculations for the currents in the circuit but claims their results are incorrect.
  • Another participant suggests writing simultaneous KCL equations and combining series resistors, questioning the need for just one KCL equation.
  • Mesh analysis and Kirchhoff's Voltage Law (KVL) are proposed as alternative methods for solving the circuit.
  • A participant provides a set of three equations based on KCL but expresses uncertainty about their correctness after checking against textbook answers.
  • There is a request for clarification on whether the equations presented are indeed KCL equations, highlighting confusion about their formulation.
  • Another participant recommends using mesh analysis or nodal analysis, suggesting these methods might be more effective for the problem at hand.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best approach to solve the problem, with multiple competing views on the use of KCL, mesh analysis, and nodal analysis remaining evident throughout the discussion.

Contextual Notes

Some participants express uncertainty about the formulation of their equations and the application of KCL, indicating potential limitations in their understanding of the circuit analysis methods being discussed.

Paymemoney
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Homework Statement


Determine the current in each branch of the circuit in the below diagram.
http://img341.imageshack.us/img341/7901/kclquestion.jpg

Homework Equations


V=IR
P=VI

The Attempt at a Solution


This is what i have done but it is incorrect.
Vtotal=16V
V=IR
[tex]Io1=\frac{16.00}{8.00}[/tex]
=2.00A

[tex]Io2=\frac{16}{6}[/tex]
=0.75A

[tex]Io3=\frac{16}{1}+\frac{16}{3}[/tex]
=21.3A

P.S
 
Last edited by a moderator:
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Paymemoney said:

Homework Statement


Determine the current in each branch of the circuit in the below diagram.
http://img341.imageshack.us/img341/7901/kclquestion.jpg

Homework Equations


V=IR
P=VI

The Attempt at a Solution


This is what i have done but it is incorrect.
Vtotal=16V
V=IR
[tex]Io1=\frac{16.00}{8.00}[/tex]
=2.00A

[tex]Io2=\frac{16}{6}[/tex]
=0.75A

[tex]Io3=\frac{16}{1}+\frac{16}{3}[/tex]
=21.3A

P.S

You are not writing the simultaneous KCL equations as far as I can tell. Combine series resistors where you can, and write the 1 KCL equation for this circuit (why just 1?). Then solve it.
 
Last edited by a moderator:
Use mesh analysis and KVL
 
Zayer said:
Use mesh analysis and KVL

Is there a reason to pick KVL over KCL here? Just curious.
 
After redoing the question this is what i have done:

Three equations:

Equation 1: Io3=Io1+1o2

Equation 2: 8-(4)Io2-(6)Io3=0

Equation 3: 4-(8)Io1-(6)Io2=0

Substitute Equation 1 into Equation 2
Equation 4
8-(4)Io2-(6)(Io1+Io2)=0
8=(10)Io2+(6)Io1

Equation 4 - Equation 3

8=(10)Io2+(6)Io1 - 4=(8)Io1+(6)Io2

Io2=0.90Amps

Substitute Io2 into Equation 3

Io1=\frac{4-(6*0.90)}{8}

=0.175Amps
Subsitute Io1 and Io2 into Equation 1

Io3=Io1+Io2
=0.90+0.175
=1.075Amps

I checked with the book's answers and my solutions are incorrect. Can someone tell me where i have gone wrong.
 
I do not understand your equations. Are they meant to be KCL equations? The KCL only involves the voltage at that top node, and the 3 currents that flow out of that node.
 
yes they are KCL equations
 
ok thanks i know how to do it now.
 

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