If the cross-section of a wire of fixed length is doubled, how does the resistance of that wire change?

Question

Halved

Doubled

Unchanged

Quadrupled

Answer 1

Resistance is directly related to the cross-sectional area of a wire, so for each scenario you gave, the effect for resistance should be the same.

Answer 2

double the cross sectional area, and the resistance is cut in half.

But you said just "cross-section", which could mean diameter.

Double the diameter and the area goes up by 4,  which means the resistance goes down by 4.

.

Answer 3

R1=(ro)XL/A,R2=(ro)XL/2A,then R2/R1=(ro)XL/2A  / (ro)XL/A=1/2,

so the resistance will be halved