**P. 4681.** The chain of resistors made of \(\displaystyle 3N\) resistors as shown in the *figure* can be closed in two different ways.

\(\displaystyle a)\) The terminals at points \(\displaystyle A\) and \(\displaystyle C\) are connected and also the terminals at point \(\displaystyle B\) and \(\displaystyle D\) are connected.

\(\displaystyle b)\) The terminals at points \(\displaystyle A\) and \(\displaystyle D\) are connected and also the terminals at \(\displaystyle B\) and \(\displaystyle C\) are connected. (Möbius band.)

In which case will the equivalent resistance of the system between \(\displaystyle A\) and \(\displaystyle B\) be greater?

(6 points)

**Deadline expired on 10 December 2014.**