A famous problem in electronics or physics course,is the following---
Consider an infinite 2d grid of resistors having resistance of equal value.Find the resistance between any two nodes in the grid.
This problem has been discussed in nerd sniping,and in-
Simpler versions of this often crops up in various college/university/competitive exams,and is now-a-days considered a "famous" problem--- (see last paragraph of https://www.mathpages.com/home/kmath668/kmath668.htm)
Interestingly,I could not find it's reference in most classic circuit analysis/electronics textbooks! So,How did it rise to popularity and what is the original source of this?Did this come up on the internet or excercise of some book or otherwise?