Circuit diagram: find the equivalent resistance

In summary, the conversation is about a problem with resistors and finding the total resistance. The person has narrowed it down to 4 resistors but is unsure how to handle the ones that are circled. They are looking for guidance and have shown their work so far. Through discussion, it is determined that the circled resistors are in parallel and can be simplified. The conversation also touches on the concept of voltage sources and how they can be connected in parallel.
  • #1
tensor0910
Gold Member
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Homework Statement



problem in title:

Homework Equations

1/Rtotal = 1/r1 + 1/r2...[/B]

The Attempt at a Solution


[/B]
I can get it down to 4 resistors...but the one's I have circled I don't know how they behave. I just need a little kick in the right direction lol. Thank you in advance!

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  • #2
tensor0910 said:

Homework Statement



problem in title:

Homework Equations

1/Rtotal = 1/r1 + 1/r2...[/B]

The Attempt at a Solution


[/B]
I can get it down to 4 resistors...but the one's I have circled I don't know how they behave. I just need a little kick in the right direction lol. Thank you in advance!

View attachment 220816
Can you show your work? It looks like those resistors fold up pretty well...
 
  • #3
tensor0910 said:
I can get it down to 4 resistors..
Please show your work.

If you are on the right track, two of the four resistances can be converted into one resistance and only 3 resistors remain in the circuit, two of which are your circled ones. You could then see how they behave.
 
  • #4
here is my work so far. sorry for the delay
circuit.jpg
 

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  • #5
Okay, so what's the next step? Can you find any more resistances that are in parallel?

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  • #6
Resistance in parallel means they have 2 common points.
 
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  • #7
ok I got it now. Sorry guys not my strongest subject lol. Thanks for all the help!
 
  • #8
Suppose your last diagram was rearranged into the diagram below. Then is it clear what the next step is? The two diagrams are equivalent.
Untitled 1.png


EDIT: I was too slow. My drawing skills are not worth s*&t.
 

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  • #9
FactChecker said:
Suppose your last diagram was rearranged into the diagram below. Then is it clear what the next step is? The two diagrams are equivalent.
View attachment 221057

EDIT: I was too slow. My drawing skills are not worth s*&t.

see that makes sense to me. they're in parallel. But my book has this for example: ( Figure P2.8)
There's two different voltage sources but they're connected in parallel, right? How can that be?

upload_2018-2-25_20-59-51.png
 

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  • #10
tensor0910 said:
see that makes sense to me. they're in parallel. But my book has this for example: ( Figure P2.8)
There's two different voltage sources but they're connected in parallel, right? How can that be?
upload_2018-2-26_7-17-40.png

I don't see any voltage sources connected in parallel. Both of the the sources are in series with current supplies.
 

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Related to Circuit diagram: find the equivalent resistance

1. What is a circuit diagram?

A circuit diagram is a graphical representation of an electrical circuit. It uses symbols to show the components of the circuit and the connections between them.

2. What is equivalent resistance?

Equivalent resistance is the total resistance of a circuit or a portion of a circuit, when all the resistors are replaced by a single resistor. It represents the total opposition to the flow of current in a circuit.

3. Why is it important to find the equivalent resistance in a circuit?

Finding the equivalent resistance in a circuit is important because it allows us to simplify complex circuits and make calculations easier. It also helps us understand the behavior of the circuit and determine the flow of current.

4. How do you find the equivalent resistance in a circuit diagram?

To find the equivalent resistance in a circuit diagram, you can use various methods such as the series and parallel combination of resistors, the delta-star transformation, or the use of Kirchhoff's laws. These methods involve applying mathematical equations to determine the total resistance.

5. Can the equivalent resistance in a circuit be greater than the sum of individual resistances?

Yes, the equivalent resistance in a circuit can be greater than the sum of individual resistances. This can happen in circuits with resistors connected in parallel, where the equivalent resistance is always less than the individual resistances. However, in circuits with resistors connected in series, the equivalent resistance can be greater than the sum of individual resistances.

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