What Is the Effective Resistance Between A and F?

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Discussion Overview

The discussion revolves around calculating the effective resistance between points A and F in a circuit. Participants explore different configurations of resistors and their implications on the overall resistance, considering both theoretical and practical aspects of circuit analysis.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant suggests that the first resistance might be ignored, leading to a calculation of effective resistance as 1Ω for two 2Ω resistors in parallel.
  • Another participant proposes that all three resistors could be in parallel, resulting in an effective resistance of 2/3Ω.
  • A different perspective indicates that if the upper and lower loops are ignored, the total resistance could be considered as 6Ω.
  • Some participants emphasize the importance of recognizing nodes in the circuit, suggesting that A, B, and D are the same node, as well as C, E, and F.
  • There is a question about whether the configuration leads to each resistor being in parallel with each other, prompting further clarification and diagrammatic representation.

Areas of Agreement / Disagreement

Participants express differing views on how to approach the circuit analysis, with no consensus on the correct effective resistance or the configuration of the resistors. The discussion remains unresolved with multiple competing interpretations.

Contextual Notes

Participants highlight the need for careful consideration of circuit nodes and potential connections, indicating that assumptions about the circuit layout significantly affect the calculations. There are unresolved mathematical steps and dependencies on the specific circuit diagram provided.

niktoo1
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(please check attachment)
Calculate the effective resistance between A and F

Initially, I thought that the first resistance is ignored and the current takes the lower path. Then 2Ω and 2Ω are in parallel giving an effective resistance of 1Ω.

However, it could also be that all three are in parallel and thus give an effective resistance of 2/3 Ω.
If the upper and lower loops are ignored, the resistance is 6Ω!
What is the correct answer??
 

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hi niktoo1! welcome to pf! :smile:
niktoo1 said:
Initially, I thought that the first resistance is ignored and the current takes the lower path.

hint: wouldn't that only be if the current through BC and CD was flowing the same way? :wink:
However, it could also be that all three are in parallel and thus give an effective resistance of 2/3 Ω.
If the upper and lower loops are ignored, the resistance is 6Ω!

hint: if two points are shown joined by a zero-resistance wire, then they must be at the same potential

so you can re-draw the diagram omitting the wire completely, and showing those two points as the same point :wink:
 
Don't ignore anything. Redraw realizing that A, B, and D are the same node and C, E, and F are also the same.
 
attachment.php?attachmentid=65681&stc=1&d=1389875734.jpg
 

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tiny-tim said:
so you can re-draw the diagram omitting the wire completely, and showing those two points as the same point :wink:


Does that mean that each resistor is in parallel with each other?
 
niktoo1 said:
Does that mean that each resistor is in parallel with each other?

what diagram do you get? (mark it with A BD and CE as in the original diagram)
 
niktoo1 said:
Does that mean that each resistor is in parallel with each other?

Which part of post #4 did you not understand?
 

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