Question

Solution??
A wire has Resistance 12 ohm. It is bent in the form of a circle. The effective resistance between two points a cross a diameter is

Answer 1

The wire when wound into circle the length or wire between two diametric points will be equal i.e..half of the perimeter of the circle...
since resistance is directly proportional to length....both the parts either side of assumed diameter will have same resistance and can be said to be connected parallelly so the equipment resistance becomes (6*6)/(6+6)=3 ohms.