Theory Group Puzzles

Puzzle Set 1: Posed in the Year-end Special Theory Group contest
An interesting set which teases one's curiosity with a network of resistances and a pack of cards! It also has a question posed by a Fields Medal winner.
Questions     Hints
Puzzle Set 2: Pi Special
This will not give you the best ways to get π. But certainly quirky ones!
Questions     Encrypted solution

To publish your puzzles here on the webpage, please send them to Sharmila.Balamurugan(at)warwick.ac.uk