Engineering Need help finding equivalent resistance in a circuit.

AI Thread Summary
The discussion revolves around finding the equivalent resistance in a circuit using delta-wye transformations. Participants suggest treating pairs of 3 kΩ resistors as 6 kΩ resistors to simplify the circuit analysis. The calculation involves combining resistors in parallel and series, leading to an intermediate equivalent resistance of 4.8 kΩ. However, confusion arises regarding the correct nodes and the final equivalent resistance, which is ultimately clarified to be 16.8 kΩ. The focus remains on accurately identifying the nodes and applying the correct transformations to solve the problem.
naivy
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Homework Statement



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Homework Equations



delta wye transformations?

The Attempt at a Solution



PM9Qm.png

I feel like I should do delta wye transforms here, but that doesn't really lead me anywhere. Am I missing how I should do the problem?
 
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Perhaps if you treated the two pairs of 3 kΩ resistors as two 6 kΩ resistors, you would realize the next step.
 
Oh, wait... treat them as 6 kΩ resistors and then they become resistors in parallel?

In that case, does the whole half above A become equivalent to 4.8 kΩ? If so, then the whole circuit would have an equivalent resistance of 14.4 kΩ? Is that right? Or did I take your hint the wrong way...
 
Your thinking and answer was wrong.

What is each 6 kΩ in parallel with?

Where is A?
 
So I figured the following:

wQWD1.png


Treat the boxed resistors as 6 kΩ and then treat those to be in parallel with the 4 kΩ resistors under them.

Then we can treat the two pieces on the top (the two sets of parallel resistors) to be parallel with each other and be equivalent to 4.8 kΩ.

The region I'm thinking of as being equivalent to 4.8 kΩ is shown in the circle below.

QcQkN.png


Then, we can just treat the 4.8 kΩ to be in series with the other four 3 kΩ resistors to get an answer of (4.8 kΩ + 12 kΩ) 16.8 kΩ.

Can you please guide me as to where I messed up? Thank you so much for your help!
 
You're supposed to be finding the resistance between A and B. You have to keep the A node!
 
BGHCy.jpg
 
That's correct.
 

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