A rod of length / and radius r is held between two rigid walls so that it is not allowed to expand. If its temperature is increased, then the force developed in it is proportional to

Young's modulus for the material of a rod is Y and its coefficient of linear expansion is alpha . A rod of length l and cross-section A of this material is kept in between two rigid supports and its temperature is increased by t^(@)C . The force developed inside the rod is

A rod of length l and area of cross-section A is heated from 0^(@)C to 100^(@)C . The rod is so placed that it is not allowed to increase in length, then the force developed is proportional to

A metal rod has length L, radius of its cross-section r. Youngs modulus Y and thermal coefficient of linear expansion is α.It is clamped between two rigid supports with negligible tension. If its temperature is increased by T^@C , then force exerted by the rod on any of the supports is