1. The problem statement, all variables and given/known data In the circuit attached below, what's the resistance between A and B? 2. Relevant equations 3. The attempt at a solution I'm finding it difficult to interpret this thing. Are resistors 1 and 2 in series or parallel? What does the loop above 1 and 2 actually do, in terms of how much current would flow round it? It has no components in it. I really have no idea what's going on in the diagram. I'm guessing it involves Kirchhoff's current and voltage laws but I'm struggling to actually apply those here. Thanks for any help!