In figure (14-E1) the upper wire is made of steel and the lower of copper. The wires have equal cross section. Find the ratio of the longitudinal strains developed in the two wires.

Here, the wires are of equal length(L) and cross-sectional area(A). Let the force produced by the load across them be F which is same for both the wires.

Young modulus of the steel,

Young modulus of the copper,

Let the elongation in steel be and that on copper be .

The strain in the steel wire is

The strain in the copper wire is

Hence,