Question

A wire of length 1m and radius 0.1 mm has a resistance of 100 Ω. Find the resistivity of thematerial.

Answer 1

Answer:

6.91 x 10^4

Explanation:

Factors of resistance - length and area which are directly proportional to it then

   R = pl/A

   given, R = 100 ohm ,  length = 1m , Area of wire = area of cylinder

     then ,

               p = R x A / l

                 p = 100 x 2 pi 0.1 [ 0.1 + 1 } / 0.1

                 { : Area of cylinder = 2pi x r(radius) [ r+l} }

                     p = 6.91 x 10^4