Equivalent resistance in a complex circuit

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Homework Help Overview

The discussion revolves around calculating the equivalent resistance in a complex circuit involving resistors R1, R2, R3, and R0, with a power supply connected between specific points. The participants are exploring the relationships between the resistors and the implications of circuit branches on current flow.

Discussion Character

  • Exploratory, Conceptual clarification, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the series and parallel relationships between resistors, with some confusion about the role of branch D. Questions arise regarding the treatment of open circuits and the application of voltage across parallel resistors.

Discussion Status

Some participants have provided guidance on how to simplify the circuit by ignoring irrelevant branches, while others have successfully calculated parts of the circuit but are still grappling with specific current calculations. There is an acknowledgment of progress, but not all aspects have been resolved.

Contextual Notes

Participants are working under the constraints of homework rules, which may limit the information they can share or the methods they can use. The complexity of the circuit and the presence of open branches are key points of discussion.

PhysicsMan999
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Homework Statement



  1. In the circuit shown, R1 = 0.810 Ω, R2 = 8.10 Ω, R3 = 81.0 Ω, and R0 = 810 Ω.
    See attachment

  1. Calculate the equivalent resistance of the circuit when a 7.70 V power supply is connected between points A and C.
    Calculate the current through R0 and R1

Homework Equations


Series: resistances sum
Parallel: 1/Req=1/R1+1/R2...

The Attempt at a Solution


Okay so I'm not really understanding circuits well. From what I would gather R3 and R0 would be in series, but I'm just really confused about R1 and R2. And I'm not even 100% sure if R3 and R0 are actually in series since it branches off to D between them as well..
 

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You're correct that R3 and R0 are in series. Now combine them and notice what happens with the circuit.

Now, why doesn't it matter that D is in between them? Because in this particular scenario, the D branch is an open circuit, so there will be no current flow in it, so you can treat the circuit as if thst branch isn't even there.

So if the B branch is also an open circuit, then...
 
I think you should redraw the circuit, leaving off what is irrelevant, including a piece of wire going nowhere and labelled D. Then see what you have.
 
Thank you guys! I found R0 and R3 are in series with each other, and so are R1 and R2, and these two series are in parallel with each other. I managed to calculate Req, and the current through R0, but now I'm having trouble calculating the current through R1..I now that parallel resistors are supposed to have the same change in voltage across resistors, but I'm not really sure how to apply that here. I thought that the voltage change would be 7.7, and just divided that by R1 for the current, but that was wrong.
 
Figured it out guys! Thanks for the help! Couldn't find an edit button so sorry for the double post just didn't want to unnecessarily take up more of anyones time than needed.
 

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