Using Kirchhoff's Laws to Find Currents, Source Current and Power Dissipated

AI Thread Summary
The discussion focuses on applying Kirchhoff's Laws to analyze a circuit with a 10V source, aiming to determine the currents (i1, i2, i3) and the power dissipated by resistors. Participants emphasize the importance of understanding Kirchhoff's Current Law (KCL) and Kirchhoff's Voltage Law (KVL) in solving circuit problems. There is a struggle with the concepts, particularly in distinguishing between current and voltage, and how to apply these laws correctly. Clarifications are provided, explaining that KCL states the sum of currents entering a junction equals those leaving, while KVL asserts that the total voltage around a closed loop must equal zero. The conversation highlights the need for a deeper grasp of these fundamental principles to effectively solve circuit problems.
  • #51
So based on the circuit and resistors etc, we've gotten equations for KVL. How do those equations translate into the other equation i5 = i1 + i2 + i3? I have another tutorial on this tonight but I really want to make a bit more progress.
For my own review I know that:
Right Loop: 40i2 -80i3 = 0
Middle Loop: 20i1 - 40i2 = 0
Left Loop: 10i5 + 20i1 = 10

I mean, is it simple algebra so each equation comes to 0, 0 and 10? Ie, i3 would be 1, i2 would be 2, i1 would be 4?
 
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  • #52
hi cschear87! :smile:
cschear87 said:
Right Loop: 40i2 -80i3 = 0
Middle Loop: 20i1 - 40i2 = 0

I mean, is it simple algebra so each equation comes to 0, 0 and 10? Ie, i3 would be 1, i2 would be 2, i1 would be 4?

i'm not really following you :confused:

those two equations tell us the ratios: i1 = 2i2 = 4i3
Left Loop: 10i5 + 20i1 = 10
So based on the circuit and resistors etc, we've gotten equations for KVL. How do those equations translate into the other equation i5 = i1 + i2 + i3?

the first 2 equations, in 3 unknowns, give you only the ratios between those 3 unknowns (because 3 = 2 + 1)

the last 2 equations (the equations with 15) give you a total of 4 equations in 4 unknowns, which enable you to solve them completely (because 4 = 4)
I have another tutorial on this tonight but I really want to make a bit more progress.

you need to ask for help on solving simultaneous equations :smile:
 
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