Question

A wire of resistance 8r is bent in the form of circle . what is the effective resistance between its ends of the diameter

Answer 1

it will be 2 r
because the wire is now bent to form a circle and if the points are on diameter then the wire is divided into two parts of resistance 4 r each and they will be in parallel resistance so the answer is
1/4+1/4 =1/r
1/2=1/r
2=r