What amount of work is done in increasing the length of a wire through unity?

The force constant of a wire is K. What is the work done in increasing the length of the wire by l ?

If the force constant of a wire is K, the work done in increasing the length of the wire by l is

This work done to increase the length in a wire by load 'Mg' is

This work done to increase the length in a wire by load 'Mg' is

What amount of work is done in reading this book in terms of scientific definition of work?

The amount of work done in increasing the voltage across the plates of capacitor from 5 V to 10 V is W. The work done in increasing it from 10 V to 15 V will be

The amount of work done in increasing the voltage across the plates of capacitor from 5 V to 10 V is W. The work done in increasing it from 10 V to 15 V will be

When a wire is stretched, an amount of work is done. What is the amount of work done in stretching a wire through 0.1 mm, if its lengths is 2m and area of cross-section 10^(-6)m^(2)(Y=2xx10^(11)N//m^(2))

The work done in increasing the length of a one metre long wire of cross-sectional area 1 mm^(2) through 1 mm will be (Y = 2 xx 10^(11) Nm^(-2))

Why is it necessary to do work to increase the length of a wire by stretching it? Which form is this work converted into?