Potentials of the points in the electrical circuit

[Petrulis]

Homework Statement

So, first of all, here is a drawing of a circuit:

http://img253.imageshack.us/my.php?image=hexabj4.jpg

The resistance of each hexagon wire is r.

I need to find the resistance of this circuit when it is connected to the source with points A and B.

I know that in this case I need to find the points in the circuit which potentials are equal. Then I should be able to simplify this circuit and find out the resistance of it.

So I know what I have to do, but I don't know how to do it. I have tried searching the internet, but I haven't found any resourses which explain the process.

Do you know any resources, articles or something similar which explain how to find the points in the circuit which have the same potentials?

Any help or suggestion would be appreciated.

 

[mjsd]

I think the trick is to put in a test current (from memory)

 

[learningphysics]

What you can do is apply a voltage V. ie: The +V potential is connected to A... 0 is connect to B.

try to use symmetry. let k be the potential to the upper left of B... what are all the other potentials in terms of k and V...

try to find k in terms of V. what is the net current going through this network of resistors...

 

[mjsd]

I believe this is equivalent to the test current approach

 

[learningphysics]

I believe this is equivalent to the test current approach

yeah, sorry. I didn't see your post before I posted.

 

[mjsd]

no need to apologise... I just thought the OP may not see it that way

 

[Petrulis]

Thanks for answers.

I was really talking about a little bit different way for solving this kind of problems.
For example, please have a look at this picture:

http://img340.imageshack.us/my.php?image=copyofhexaoe6.jpg

Hexagonal circuit has got a vertical symmetry axis, so the potentials of the points K, L and M are the same, so we can connect these three points.

So I am looking for this kind of examples how to solve similar problems. Do you know any good resources which show more examples and methods how to do that?

 

[Petrulis]

Please somebody help me with this problem. I just need some resources which I could use for learning.