Question

Due to change in length and area of cross-section of a conductor, resistance of conductor changes while resistivity does not change. Why?

Answer 1

Resistance (R) depends on the dimensions of the conductor.

R = `rho l/A`

So, if length (l) or area (A) changes, resistance changes.

Resistivity (ρ) is a property of the material and depends only on the nature of the material and temperature, not on dimensions.

Hence, resistance changes, but resistivity remains unchanged.