Question

the resistance of a conductor is inversely proportional to square of the radius or not

Answer 1

Yes

Because R=p×l/A

A =pi×r^2

Answer 2

no it is not proportional to square of the radius it is v=RI
where I is current flowing through conductor, v Is potential difference
Also in case of resistivity
which rho ,p= R×L\A
where L is length of conductor, A is area of cross section of two ends of conductor
so R= rho×A/L