Determining the equivalent resistance of an irreducible network of resistors

[richyw]

Homework Statement

Alright so I am having trouble finding the equivalent resistance of something like this

Without "hooking it up" to a current source and solving a large system of equations to find the voltage drop across the network and therefore the resistance.

Is there a faster way to do this (say in an exam situation)?

Homework Equations

-kirchoffs laws
-parallel/series equivalent resistances
V=IR

The Attempt at a Solution

As I described gets me the answer. Want to know if it is the quickest way!

 

[gneill]

Unless there's a symmetry to exploit with the given values of the resistors (so that the potentials at either end of resistor R3 must be equal), there are two choices:

1. Add a supply and write three loop or nodal equations and solve

2. Use a Δ-Y transformation on one of the resistor loops and continue reducing the network