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neonstrobe

Joined May 15, 2009
200
My final objective is finding the voltage of V1. I can do that by using KVL , i already found the voltage of R2 which is 24V and 2mA but to find the KVL i need the last voltage of R1, how can i find that voltage, how does the 2mA current divide there?

(R5 is 4V with 4mA passing throught it, i dont know if that 4mA current will be the one going throught the resistor 3K)

View attachment 138304

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Don't think you have enough information to find V1. The value of V1 will change the currents.
 

WBahn

Joined Mar 31, 2012
32,833
My final objective is finding the voltage of V1. I can do that by using KVL , i already found the voltage of R2 which is 24V and 2mA but to find the KVL i need the last voltage of R1, how can i find that voltage, how does the 2mA current divide there?

(R5 is 4V with 4mA passing throught it, i dont know if that 4mA current will be the one going throught the resistor 3K)

View attachment 138304
Your description of your work isn't quite good enough -- saying something like "R5 is 4 V with 4 mA" doesn't tell us a VERY important piece of information -- the polarity of the voltage (and current).

Also, how did you determine the voltage across R5? Or was that information that was given with the problem?

The schematic shown is unsolvable without knowing the voltage across or current through at least one of the resistors (or current through a voltage source or voltage across the current source). To see that this is the case, imagine building the circuit as shown using a variable source for V1. You can turn the dial to a random setting and no one will be able to tell you what it's voltage is based only on the information in the schematic.
 

WBahn

Joined Mar 31, 2012
32,833
I looked at that and from what I see V1 should be the same as V2
Only way that the meter would show 2mA
I'm pretty sure that it is not a meter, but rather an independent current source that is delivering 2 mA. Both the symbol used and the reference designator are the normal ones used for a current source. A meter generally has a stylized meter face with an 'A' or a 'V' to indicate the type of meter.

But if it WERE an ammeter, you would be correct.
 

WBahn

Joined Mar 31, 2012
32,833
I assumed that was a 2mA current source, as the label says I1. (Like V1 only current).
I think it's a 2 mA current source, as well.

But that means that, unless you are given additional information (beyond what is provided by the schematic alone), there is no unique solution -- V1 can literally be anything.
 

be80be

Joined Jul 5, 2008
2,395
@neonstrobe: Oops - I thought you were the TS responding. Clearly you already know that it has no solution as is.
That's why I was thinking it maybe a meter there is no way to to figure it out if not a reading some where that's useful.

I figured maybe a mistake on the drawing and they used that for a meter.
 

WBahn

Joined Mar 31, 2012
32,833
That's why I was thinking it maybe a meter there is no way to to figure it out if not a reading some where that's useful.

I figured maybe a mistake on the drawing and they used that for a meter.
I rather doubt it. If I had to guess, I'd guess that the problem statement gives another parameter and I suspect it is the voltage across R5 (and probably stated so as to indicate the polarity). But we can't know until the TS provides some more information.
 
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