KIRCHOFF's Law: Solving Circuit

AI Thread Summary
The discussion focuses on applying Kirchhoff's Law to solve a circuit with two loops, resulting in equations that determine the currents I1 and I2. The calculations yield I1 as 1.5 and I2 as approximately 2.1666. Participants clarify how to determine the direction of current flow, emphasizing that consistency in defining clockwise (CW) and counterclockwise (CCW) is crucial. If the assumed direction is incorrect, the resulting negative value indicates the actual current flows in the opposite direction. The conversation concludes with a reminder to keep questions relevant to the topic at hand.
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according to circuit
In Left Loop Current is I1 and Right Loop is I2

Now Loop Left
10-8I1-3I1-I2=0
which becomes
10-8I1-3I1+3I2=0
11I1-3I2-10=0 ------------eq 1


Now Loop Right
15-6I2-3I2-I1=0
15-6I2-3I2+3I1=0
3I1-9I2+15=0
I1-3I2+5=0 ---------------eq 2

Deduct eq 2 from eq 1

10I1-15=0
I1= 1.5
from eq 2 we have
I2=2.1666

Now I want to ask
I= I1-I2
or
I=I2-I1
or what and how to take decision what i have to do
 
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When you consider the magnitude of the current it should be +ve. So I = I2 - I1
 
Thanks Bhat i got your point, and one thing more what will be the direction current on both the loop
 
Since you defined I1 and I2 to be clockwise for positive currents, and both currents are in fact positive, then the direction of each is _____?
 
yes direction of current is positive in the diagram what if direction is counter-clock wise and one loop clock wise and othe one counter clock wise
 
It doesn't matter how you define things, as long as you are consistent. When you assume one loop to be CW and the other CCW, current on the R3 will be sum of the currents in both loops. If you have assumed wrong (that is, currents don't go as you expect them) one of the currents in your final solution will be negative - and that's perfectly OK, that just means current flows in the opposite direction.
 
Thanks Borek now i 'm clear about Kirchoff
 
what is a comlex dc circuit
 
haroon1972 said:
what is a comlex dc circuit

Hello harroon1972, welcome to PF!

If you have a separate question unrelated to what the OP (original poster) was asking, you should start a new thread for it. I'd be happy to help, but you need to be more specific. As it stands right now, it's not very clear what you're asking.
 
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