the ans. will be
we know R=s(l/a).where s=specific resistance of the element, l=length of the element,a=circular base area of the element.
now for the first case if resistance was
now the diameter of the element is doubled ,so the radius of the circular base is also doubled.
here the volume of the element will remain constant,so the product of the area & length remains the same i.e.
since the element remains same s will be same for both the cases.