Question

A solid cylinder of radius r, length l is recasted into a hollow cylinder of inner radius r and outer radius 2r keeping the volume constant. The ratio of electrical resistance of solid cylinder to hollow cylinder assuming that the resistivity remains constant throughout the process is

Answer 1

first part of radius is 2 r and length is l so you find the volume of hollow cylinder by using formula okk and after in second part the radius is 2r and length is constant okk so in two parts you find the volume of hollow cylinderical by using formula after then the two volume which you are calculate both will added okk