Equivalent resistance in a complex circuit

Click For Summary
SUMMARY

The discussion focuses on calculating the equivalent resistance of a complex circuit with resistors R1 (0.810 Ω), R2 (8.10 Ω), R3 (81.0 Ω), and R0 (810 Ω) connected to a 7.70 V power supply. It is confirmed that R3 and R0 are in series, while R1 and R2 are also in series, with these two series combinations being in parallel. The user successfully calculated the equivalent resistance (Req) and the current through R0, but initially struggled with the current through R1, ultimately resolving the issue with guidance from forum members.

PREREQUISITES
  • Understanding of series and parallel resistor configurations
  • Familiarity with Ohm's Law
  • Basic circuit analysis techniques
  • Ability to interpret circuit diagrams
NEXT STEPS
  • Study the principles of series and parallel circuits in detail
  • Learn how to apply Ohm's Law in complex circuits
  • Explore circuit simulation tools like LTspice for practical understanding
  • Investigate advanced topics such as Thevenin's and Norton's theorems
USEFUL FOR

Students studying electrical engineering, hobbyists building circuits, and anyone looking to deepen their understanding of circuit analysis and resistor configurations.

PhysicsMan999
Messages
32
Reaction score
0

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..
 

Attachments

  • physics.gif
    physics.gif
    3 KB · Views: 576
Physics news on Phys.org
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.
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 13 ·
Replies
13
Views
2K
Replies
9
Views
2K
Replies
4
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K