"Peter L. Peres" wrote: > On Sat, 27 Jul 2002, Dave Tweed wrote: > >"Peter L. Peres" wrote: > > > On Fri, 26 Jul 2002, Wouter van Ooijen wrote: > > > > A related 'trick' question: take a wire cube, each wire has a > > > > resistance of 1 ohm. Put a 1 Volt battery on the two diagonally > > > > opposite points on one side. How much current does the battery > > > > supply? The trick is of course that some wires carry zero current. > > > > > > I beg to differ. There are no wires that bear zero current in a cube as > > > you describe (hint: the number of edges the current has to traverse is > > > always uneven - equal to three). > > > > Check again. Remember, he specified diagonally across one face of the > > cube. There are exactly two wires that carry no current. > > > > If you apply the battery along a major diagonal, you need a different > > "trick" to solve the problem, because in that case, all wires are > > indeed carrying current. > > Maybe I misread the posting, I thought it was across a major diagonal. So, what's the answer for the major diagonal? (and what's the trick?) -- Dave Tweed -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.