Finding a voltage across 2 nodes [Check answer - work already done]

AI Thread Summary
The discussion revolves around calculating the voltage across two nodes using Kirchhoff's Voltage Law (KVL). A participant initially calculated V1 as 18V but later revised it to 37.33V after further analysis. There is confusion regarding the presence of two loops in the circuit, which impacts the calculations and assumptions about voltage signs. The need for the original question to be reposted for verification is emphasized, as it may clarify the circuit's design and the calculations involved. Overall, the conversation highlights the complexities of circuit analysis and the importance of clear problem statements.
naivy
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Homework Statement



blFU9.png


Homework Equations





The Attempt at a Solution


I got V1=18V
Here's my work:
AdrND.jpg
 
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Can you repost the original question and then rewrite your solution with some brief explanations to show what you are doing? i.e KVL (Right): V1 - Vx - 24 = 0
 
I got V1 = 37.33V, Vx= 13.33V. It checks when you plug the numbers into your schematic.

If V1 = 18V then Vx = 18 - 24 = -6V so i thru the 25K = -6/25 = 0.24 mA
whereas i thru the 5K would then be
(-3*6 - 18)/5 = -7.2 mA so that can't be right.
 
Vab = Va - Vb. Assuming Va is at V1+ and Vb is at V1-, what is V1?

Given V1, and using KVL around the right hand loop, what is Vx?
 
There are 2 loops? If so, V1 = 0!
 
Given the line drawn between V1+ and V1-, and the node 'dots', it seems a safe assumption that there are two loops, rather than just one with an errant line.

I got V1 = 37.33V, Vx= 13.33V. It checks when you plug the numbers into your schematic.

I did it your way as well though and got the same numbers, but wanted the original question reposted just to verify.
 
Two loops were my firat assumption too, but then I realized that that would make the problem pathological (viz. V1 = 0). Also, the OP calculated a finite (albeit erroneous) V1. So I decided that extra line must indicate voltage rise gnd to V1, although I did wonder why there was no arrow at the top of that line. Also, if two loops, why did the OP have - and + signs next to that line?
 
Also, if two loops, why did the OP have - and + signs next to that line?

It could possibly have been designed as a (trick) knowledge problem, rather than a circuit analysis problem. Needs more OP confirmation I suppose.
 

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