Conceptual Question about Equivalent Resistance

AI Thread Summary
Understanding circuit diagrams is crucial for determining equivalent resistance. Circuit B is confirmed to be in parallel, calculated using the formula 1/R = 1/R1 + 1/R2. Circuit A's configuration may also be parallel, as the arrangement of resistances does not need to be visually parallel to be considered so. The key point is that the connections between resistors dictate their equivalence, not their physical layout. Clarifying these concepts aids in accurately finding equivalent resistance in various circuit configurations.
jumbogala
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Homework Statement


I don't quite understand how to read circuit diagrams, so I'm not sure how to find the equivalent resistance in some cases.

What is the equivalent resistance of circuits A and B?

I drew a picture to help me explain what I'm talking about:
Circuits.jpg



Homework Equations





The Attempt at a Solution


I know circuit B is definitely in parallel, so the equivalent resistance is 1/R = 1/R1 + 1/R2.

But is circuit A in parallel, too? I think it is but I'm not 100 % sure.
 
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jumbogala said:
What is the equivalent resistance of circuits A and B?

I drew a picture to help me explain what I'm talking about:
Circuits.jpg



Homework Equations



The Attempt at a Solution


I know circuit B is definitely in parallel, so the equivalent resistance is 1/R = 1/R1 + 1/R2.

But is circuit A in parallel, too? I think it is but I'm not 100 % sure.
You are correct -- the two circuits are absolutely equivalent. It does not matter how you draw the resistance R2 as long as it is there somewhere between the two points where the wires from R2 join the wire containing R1.

"Parallel" does not mean that the resistances have to be literally parallel.
 

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