Question

A finite square grid, each link having resistance r, is fitted in a resistance less conducing circular wire. Determine the equivalenet resistance between A and B `("in" Omega)` if `r = (80//7) Omega`.

Answer 1

Correct Answer - 6
If we connect battery between A and B, then different points will be at the same potentials.
(1,2,3,4,),(5,6,7,8),(9,10,11, 12,13,14,15,16,), and (17,18,19,20)

The resulting circuit can be drawn as follows :

`R_(AB) = (21)/(40) r = (21)/(40)xx(80)/(7) =6 Omega`