Question

How is resistivity related to cross section area?

Answer 1

resistivity is inversely proportional to the area of cross section

Answer 2

As
$resistance = \frac{resistivity \times length}{area } \\ r = \frac{p \times l}{a} \: where \: p \: is \: resistivity \\ arranging \: we \: get \\ p = \frac{ra}{l} \\ \\ a \: is \: cross \: section \: area$

hence resistivity is directly proportional to cross section area