What is the Resistance Between A and B in a Circuit?

In summary, this problem is difficult to understand because it's not clear what the circuit is doing.
  • #1
Kara386
208
2

Homework Statement


In the circuit attached below, what's the resistance between A and B?

Homework Equations

The Attempt at a Solution


I'm finding it difficult to interpret this thing. Are resistors 1 and 2 in series or parallel? What does the loop above 1 and 2 actually do, in terms of how much current would flow round it? It has no components in it. I really have no idea what's going on in the diagram.

I'm guessing it involves Kirchhoff's current and voltage laws but I'm struggling to actually apply those here. Thanks for any help!
 

Attachments

  • circuit2.png
    circuit2.png
    2.9 KB · Views: 403
Last edited:
Physics news on Phys.org
  • #2
This exact problem has shown up here several times. You need to just pay attention to the definitions of serial and parallel connections and redraw the circuit. That is that POINT of the exercise, actually, more than the answer. It's to force you to pay close attention to the definitions.
 
  • Like
Likes Kara386
  • #3
phinds said:
This exact problem has shown up here several times. You need to just pay attention to the definitions of serial and parallel connections and redraw the circuit. That is that POINT of the exercise, actually, more than the answer. It's to force you to pay close attention to the definitions.
Are these just all in parallel? If I removed either of those loops I'd say what was left was three resistors in parallel, but what happens when there are two loops? Still just in parallel?
 
  • #4
Kara386 said:
Are these just all in parallel? If I removed either of those loops I'd say what was left was three resistors in parallel, but what happens when there are two loops? Still just in parallel?
Yes, it's rather trivial to note that each of the resistors has one end hooked to the input and one to the output so they are obviously in parallel. You'll need to define what you mean by "two loops" to get an answer to that, but if you draw the diagram properly it will be obvious in any case.
 
  • Like
Likes Kara386
  • #5
phinds said:
Yes, it's rather trivial to note that each of the resistors has one end hooked to the input and one to the output so they are obviously in parallel. You'll need to define what you mean by "two loops" to get an answer to that, but if you draw the diagram properly it will be obvious in any case.
I see it, thank you! :)
 

What is the total resistance?

The total resistance is the measurement of the combined opposition to the flow of electric current in a circuit. It is measured in ohms (Ω) and is calculated by adding all individual resistances in a series circuit or using complex formulas in a parallel circuit.

How do I calculate the total resistance in a series circuit?

In a series circuit, the total resistance is calculated by simply adding the individual resistances together. For example, if there are three resistors with values of 2 Ω, 4 Ω, and 6 Ω connected in series, the total resistance would be 2 Ω + 4 Ω + 6 Ω = 12 Ω.

What is the formula for calculating total resistance in a parallel circuit?

The formula for calculating total resistance in a parallel circuit is 1/Rt = 1/R1 + 1/R2 + 1/R3 + ... + 1/Rn, where Rt is the total resistance and R1, R2, R3, etc. are the individual resistances. This formula takes into account the inverse relationship between resistance and current in a parallel circuit.

How does temperature affect total resistance?

In most cases, as the temperature increases, the resistance of a material also increases. This is due to the fact that as the temperature rises, the atoms in the material vibrate more, causing more collisions and hindering the flow of electrons. However, there are some materials, such as semiconductors, that have a negative temperature coefficient, meaning their resistance decreases as temperature increases.

What is the difference between total resistance and equivalent resistance?

Total resistance refers to the overall resistance in a circuit, while equivalent resistance specifically refers to the combined resistance in a parallel circuit. Equivalent resistance takes into account the different paths that current can take in a parallel circuit, while total resistance does not differentiate between series and parallel connections.

Similar threads

  • Introductory Physics Homework Help
Replies
28
Views
1K
  • Introductory Physics Homework Help
Replies
7
Views
486
  • Introductory Physics Homework Help
Replies
3
Views
489
  • Introductory Physics Homework Help
Replies
14
Views
537
  • Introductory Physics Homework Help
Replies
3
Views
535
  • Introductory Physics Homework Help
Replies
3
Views
171
  • Introductory Physics Homework Help
2
Replies
44
Views
686
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
182
  • Introductory Physics Homework Help
Replies
6
Views
983
Back
Top