posted by kala .
a wire whose cross-sectional area is 4mm^2
is stretched by 0.1 mm by a certain load.if a similar wire double the area of cross-section is under the same load,then then elongation would be
Doubling the cross section area decreases the stress by a factor of two. The strain is also reduced by the same factor, so that the elongation is 0.05 mm (instead of 0.1 mm)
Your answer is correct.