Need to find two currents in this circuit

  • Context: Engineering 
  • Thread starter Thread starter opticaltempest
  • Start date Start date
  • Tags Tags
    Circuit Currents
Click For Summary

Discussion Overview

The discussion revolves around finding the currents I_D1 and I_D2 in a given circuit using methods such as Kirchhoff's Current Law (KCL) and Kirchhoff's Voltage Law (KVL). Participants explore different approaches to solve the problem, including mesh analysis.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Technical explanation

Main Points Raised

  • One participant expresses difficulty in applying KCL and KVL to find the currents I_D1 and I_D2, suggesting that the circuit appears simple but is challenging to solve.
  • The same participant derives a KCL equation at a node, leading to a relationship between I_D1, I_D2, and the current through a 6V source.
  • Another participant suggests that mesh analysis could be used to derive two equations for the circuit.
  • A later reply confirms that the method initially used by the first participant is indeed the simplest way to solve the circuit.
  • One participant offers a quick solution using mesh analysis, implying that it may be straightforward.

Areas of Agreement / Disagreement

There is no consensus on the best method to solve the circuit, as participants suggest different approaches (KCL, KVL, mesh analysis) without resolving which is superior.

Contextual Notes

Participants have not fully explored the implications of their equations or the assumptions behind their methods, leaving some steps and definitions potentially unresolved.

opticaltempest
Messages
135
Reaction score
0
I am trying to find the currents I_D1 and I_D2 labeled in the picture by the arrows. I am stumped on how to obtain the correct values for the currents. I am having trouble using either KCL or KVL. This circuit seems simple but has me stumped.

http://img127.imageshack.us/img127/8600/circuitvz9.jpg

If I write KCL at the node to the right of the I_D1 arrow I get

[tex]-I_{D1}+I_{D2}-I_{6V}=0 \implies[/tex]

[tex]I_{D1}=I_{D2}-I_{6V}.[/tex]

[tex]I_{6V}=\frac{6V}{43k\Omega}=140\mu A[/tex]

[tex]I_{D2}=\frac{9V}{22k\Omega}=409\mu A[/tex]

Is there an easier or different way to do this problem, perhaps using KVL instead of writing a KCL equation at the node I used?

Thanks
 
Last edited by a moderator:
Physics news on Phys.org
Yes you can also do it via mesh analysis. You would have 2 equations here.
 
opticaltempest said:
I am trying to find the currents I_D1 and I_D2 labeled in the picture by the arrows. I am stumped on how to obtain the correct values for the currents. I am having trouble using either KCL or KVL. This circuit seems simple but has me stumped.

http://img127.imageshack.us/img127/8600/circuitvz9.jpg

If I write KCL at the node to the right of the I_D1 arrow I get

[tex]-I_{D1}+I_{D2}-I_{6V}=0 \implies[/tex]

[tex]I_{D1}=I_{D2}-I_{6V}.[/tex]

[tex]I_{6V}=\frac{6V}{43k\Omega}=140\mu A[/tex]

[tex]I_{D2}=\frac{9V}{22k\Omega}=409\mu A[/tex]

Is there an easier or different way to do this problem, perhaps using KVL instead of writing a KCL equation at the node I used?

Thanks

The simplest way to solve the circuit is the one you used.
 
Last edited by a moderator:
Quick solution:

Hey this is a simple mesh anaylisis problem.. I've included a solution. I hope it helps. Cheers
 

Attachments

  • optical-tempestsprob.JPG
    optical-tempestsprob.JPG
    26.3 KB · Views: 477

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
6K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
7
Views
1K