# Homework Help: Resistance in an octahedron between adjacent vertices

1. Oct 18, 2016

### Tazi

1. The problem statement, all variables and given/known data
Twelve identical wires, each with resistance R = 1.0 ohms, are linked together to form a
octahedron. Find the resistance in an octahedron between opposite vertices and adjacent vertices( A,B for example)

picture

2. The attempt at a solution

I already found the resistance between opposite vertices (R/2) using symmetry and equipotential points but can't find any way to calculate the resistance between adjacent vertices. Do u have any tips for me?

2. Oct 18, 2016

### Staff: Mentor

Hi Tazi. Welcome to Physics Forums.

One tip: Do not use text-speak on these forums ("u" rather than "you") . It's against the rules.

What have you tried so far? Show us your best effort.

3. Oct 19, 2016

### Tazi

My attempt (resistance between points A and B): potential in point E equals to potential in point F but I'm not sure what to do about points D and C. How to find potential in those points? I tried to use Kirchoff laws but didnt find anything.

4. Oct 19, 2016

### haruspex

You can certainly get there using Kirchoff. Please show some attempt that way.
You can also go the more usual route of breaking it down into a nested combination of parallel and serial links. The first step, breaking it into two parallel paths, is obvious. After that it gets a bit tougher, but I think I see a way to use symmetry to simplify it.