Question

A wire of resistance 4r is bent in the form of a circle . What is the effective resistance between the ends of the diameter

Answer 1

The 4R gets equally divided into 4 parts of 1R. Of which, 2 each are in series and the resultant of these form a parallel connection. Therefore

Equivalent resistance is (1+1)(1+1)/(1+1)+(1+1)= 4/4 =1R