I need to calculate the equivalent resistance

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Homework Help Overview

The discussion revolves around calculating the equivalent resistance in a circuit, specifically between points A and B, as depicted in a referenced figure. Participants are examining the connections and configurations of resistors within the circuit.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to analyze the circuit by suggesting that one resistor is shorted due to a wire connection. Other participants question this assumption and discuss the implications of node connections in the circuit.

Discussion Status

Some participants have provided clarifications regarding the correctness of the original poster's interpretation of the circuit. There is ongoing exploration of how to visualize the circuit more effectively, including suggestions to rename nodes and redraw the circuit for clarity.

Contextual Notes

Participants are considering the implications of node connections and how they affect the calculation of equivalent resistance. There is a mention of the need to identify distinct nodes within the circuit.

SaiTatter
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Homework Statement


The circuit is the one in "Fig.4"
dTMsA0n.jpg

I need to calculate equivalent resistance between A and B. This is what I've tried:
w0ZCnUq.jpg

I think that the first resistor is shorted by that wire connected between A and E. Their answer looks like this, in fig 2.2.1. I'm not sure if their answer is wrong, or my idea about electricity has flaws. Thanks in advance for the explanations!
jrpmShY.jpg
 

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Welcome to the PF. :smile:

Their answer/figure is correct. Just notice how point "A" connects to one side of those 3 R resistors, and the other side of each of those 3 R resistors are all connected together.
 
Thanks berkeman! So proud to be here :).
 
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Glad to help. :smile:
 
[QUOTE="SaiTatter]
I think that the first resistor is shorted by that wire connected between A and E.[/QUOTE]

That's not correct. The wire doesn't connect one side of the resistor to the other side. It connects it to another resistor.

Note that some nodes (eg A and E) are connected together by wire so they are really the same electrical node. Try renaming node E to node A. Likewise for any other nodes that have two names. It might help to colour the wires so points that are connected together are the same colour.

How many different nodes are there? The answer only has 3.

Then redraw the circuit starting with a line of these 3 nodes. Then add the resistors between them.
 

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