Q. Two copper wires of lengths $l$ and $2l$ have radii $\ r$ and $2r$ respectively. What is ratio of their specific resistances?
A) 1 : 2
B) 2 : 1
C) 1 : 1
D) 1 : 3
Explanation
(c) The specific resistance ($\rho$) is the characteristic of the material of conductor. Its value depends only on the material of conductor and its temperature. Its value does not depend on the length and area of cross-section of the conductor.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.