Equivalent resistance in a complex circuit

AI Thread Summary
The discussion focuses on calculating the equivalent resistance and current in a complex circuit with given resistor values. Participants clarify that resistors R3 and R0 are in series, while R1 and R2 are also in series, with these two series combinations being in parallel. The confusion arises from the presence of an open circuit branch (D), which does not affect the overall circuit analysis. After some guidance, the user successfully calculates the equivalent resistance and the current through R0 but initially struggles with the current through R1. Ultimately, they resolve their confusion regarding the voltage across parallel resistors and complete their calculations.
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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