A metal rod is fixed rigidly at two ends so as to prevent its thermal expansion. If L, and Y respectively denote the length of the rod, coefficient of linear thermal expansion and Young's modulus of its material, then for an increase in temperature of the rod by T, the longitudinal stress developed in the rod is [AMU 2014]
where, L = length of the rod,
= coefficient of linear thermal expansion
and Y = Young's modulus of its material.
So, the longitudinal stress developed in the rod is independent of L