A wire of length l and cross selection area a is made of material of Young's modulus Y.If the wire is stretched by an amount x,find the work done.

A steel wire of length 4.7 m and cross-sectional area 3.0 xx 10^-5 m^2 stretches by the same amount as a copper wire of length 3.5 m and cross-sectional area of 4.0 xx 10^-5 M^2 under a given load. What is the ratio of the Young’s modulus of steel to that of copper?

A wire of length L and 3 identical cells of negligible internal resistance are connected in series. Due to the current, the temperature of the wire is raised by DeltaT in a time t. A number N of similar cells is now connected in series with a wire of the same material and cross-section but of length 2L. The temperature of the wire is raised by the same amount DeltaT in the same time t. the value of N is

A thick wire of density rho and l is hung from a rigid support .Young's modulus of the material of wire is Y.What is the increases in length of the wire due to its own weight?