# Equivalent Resistance? [duplicate]

How do you find the equivalent resistance here? (I realized it's a Wheatstone bridge, but it's unbalanced, so that doesn't help.) I tried using Kirchhoff's laws, but there is no cell given.

• No. Just practising, – Leponzo Nov 26 '14 at 17:21
• This might help you: en.wikipedia.org/wiki/… – Null Nov 26 '14 at 17:32
• If you connected +1V to point X and 0V to point Y how much current would flow? If you can work out the answer to that then you can work out the resistance between X and Y. – JIm Dearden Nov 26 '14 at 17:36
• This combination consists an unbalanced Weaston bridge, so there is a current from B to E and definately you can not solve with series/parallel method. You can use mesh analysis or Y-Δ transform en.wikipedia.org/wiki/Y-%CE%94_transform. Another interesting proposal is here physics.stackexchange.com/questions/22252/… but it is not proofed by anyone yet – GR Tech Nov 26 '14 at 21:04

It looks like irreducible network - network which does not contain series or parallel connections that can be reduced.

You can add some voltage source to X and Y terminals and do mesh analysis.

It is explained in Wikipedia mesh analysis article, and also in this video by Darryl Morrel so I will not explain it here.

• This can be found pretty easily using delta-to-wye transformations. – Eric Nov 26 '14 at 17:39
• Yea, but I saw that Null suggested that in comments, so I provided diffrent (more universal) approach. – Kamil Nov 26 '14 at 17:48