# Homework Help: Total resistance through cubic circuit

1. Oct 7, 2008

### Fizzicist

1. The problem statement, all variables and given/known data

Suppose a resistor R lies along each edge of a cube (12 resistors in all) with connections at the corners. Find the equivalent resistance between two diagonally opposite corners of the cube

2. Relevant equations

$$\Sigma$$I = 0 at a node (a junction)

$$\Sigma$$V = 0 through a loop

V=IR

3. The attempt at a solution

Not quite sure how to do this one algebraically. Would I just add up all the V/Is? how?

2. Oct 7, 2008

### Fizzicist

Not quite sure where to start...can anyone help me?

3. Oct 7, 2008

### Rake-MC

How about opening the cube out so it's flat and looking at it that way.

4. Oct 7, 2008

### Fizzicist

Interesting...is that necessary though, or could I just apply kirchoff's laws to it as it is?

5. Oct 7, 2008

### granpa

I count from any one node:
3 paths to 3 nodes which then connect by:
6 paths to 3 nodes which then connect by:
3 paths to 1 node.

connecting the 3 nodes together with wires should change nothing.

6. May 25, 2009

### AROD

are you saying just ignore those 6 connections?

7. May 25, 2009

### granpa

I think the post I was responding to was deleted.