Question

The radius of a conducting wire is doubled and length is tripled. What will be the ratio of its new resistivity to the old one? Assume the temperature is constant.

• A. $4:3$
• B. $3:4$
• C. $3:2$
• D. $1:1$

Answer 1

The correct option is D $1:1$

The resistivity of a material is constant at a given temperature. It is independent of the length and cross-section area of the conductor.
$\therefore$ the ratio of its new resistivity to the old one is $1:1$.