The increase in the length of a wire on stretching is $0.04$%. If Poisson's ratio for the material of wire is $0.5,$ then the diameter of the wire will:

The Poisson's ratio of a material is $0.4.$ If a force is applied to a wire of this material, there is a decrease in the cross-section area by $2$%. In such a case the percentage increase in its length will be: