Q. The resistivity of iron is $1 \times 10^{- 7}ohm - m.$ The resistance of a iron wire of particular length and thickness is $1\ ohm.$ If the length and the diameter of wire both are doubled, then the resistivity in $ohm - m$ will be
A) $1 \times 10^{- 7}$
B) $2 \times 10^{- 7}$
C) $4 \times 10^{- 7}$
D) $8 \times 10^{- 7}$
Explanation
(a) Resistivity of a material is its intrinsic property and is constant at particular temperature. Resistivity does not depend upon shape
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.