Question

A wire of resistance 20 ohm is bent in the form of a circle. What is the effective resistance between two points at the end of any diameter of the circle?

Answer 1

Answer:

resistance given here = 20 ohm

asit is bent into the wire so L= 2πr

so Ri = Rho*2πr/A = 20 ohm

Now resistance between two point at the end of diameter can be given by

1/R =(1/Ri/2)+(1/Ri/2) {as half of the wire attachedto the other half so it may be considered as parallel connection. }

1/R = 1/10+1/10 {Ri = 20 ohm so. Ri /2= 10 ohm}

or 1/R = 2/10

so, R = 5 ohm {across ends of diameter }

Hope it helps you