Calculating Equivalent Resistance in a Hexagonal Prism Circuit

Click For Summary
The discussion focuses on calculating the equivalent resistance between points P and Q in a hexagonal prism circuit with varying resistances. Participants debate the redundancy of certain wires due to the balanced Wheatstone bridge configuration, leading to different resistance calculations, with some suggesting values like 3R/2 and 33R/28. The importance of symmetry in simplifying the circuit is emphasized, with suggestions to use nodal analysis and Y-Δ transformations, although some participants express restrictions on their use. The conversation reveals confusion over the application of the Wheatstone bridge principle and the impact of symmetry on current flow, ultimately leading to various proposed solutions. The complexity of the circuit and the need for careful analysis are highlighted throughout the discussion.
  • #31
gneill said:
The correct one :smile:
I'm not sure it's the right time yet to give away the answer.

I did the same you did ...

So your answer is 33R/28 ?
 
Physics news on Phys.org
  • #32
cupid.callin said:
I did the same you did ...

So your answer is 33R/28 ?

Nope. A bit smaller.
 
  • #33
smaller than 1.7R ?

Here's how i solved ... Bold black lines are the resistances

attachment.php?attachmentid=33586&stc=1&d=1301182953.jpg
 

Attachments

  • HEX2.jpg
    HEX2.jpg
    12.1 KB · Views: 512
  • #34
What happened to the resistances ab, cd, a'b', c'd' ?
 
  • #35
there won't be any current through them right? so we can just remove them. Is that wrong ?:confused:
 
  • #36
cupid.callin said:
there won't be any current through them right? so we can just remove them. Is that wrong ?:confused:

I don't think that you can assume that there will be no current through them.
 
  • #37
gneill said:
Sure. I've only labeled some of the resistances, the rest should be obvious by color code and symmetry.

Did you get 17R/16?
 
  • #38
Abdul Quadeer said:
Did you get 17R/16?

Nope. A bit too small.
 
  • #39
Here's the next step in the simplification. The diagram is still symmetrical, so the Delta-Y transformations at either end will be the same...
 

Attachments

  • HEX3.jpg
    HEX3.jpg
    9.4 KB · Views: 408
  • #40
Yup. That's what I had & did.
 
  • #41
I got it - 23R/20
Thanks!
 
  • #42
Abdul Quadeer said:
I got it - 23R/20
Thanks!

Yes, that's it. Attached is the summary of the simplifications used.
 

Attachments

  • HEX1.jpg
    HEX1.jpg
    23.3 KB · Views: 463

Similar threads

  • · Replies 10 ·
Replies
10
Views
825
  • · Replies 31 ·
2
Replies
31
Views
4K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
9
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 15 ·
Replies
15
Views
4K
  • · Replies 1 ·
Replies
1
Views
719
  • · Replies 2 ·
Replies
2
Views
622