Question

a wire of resistance 5 ohm is bent in a form of a closed circle.what is the effective resisitance between the two points at ends of any diameter of the circle?

Answer 1

$\frac{1}{r} = \frac{1}{5} + \frac{1}{5} \\ \\ \frac{ 1}{r} = \frac{2}{5} \\ \\ r = \frac{5}{2} \\ \\ r = 2.5 \: ohm$