STATEMENT - 1 : When a rod lying freely is heated, no thermal stress is developed in it.
and
STATEMENT - 2 : On heating, the length of the rod increase.

STATEMENT - 1 : A metallic rod placed upon smooth surface is heated. The strain produced is ZERO. STATEMENT - 2 : Strain is non-zero only when stress is developed in the rod. STATEMENT - 3 : Two metallic rods of length l_(1) and l_(2) and coefficient of linear expansion alpha_(1) and alpha_(2) are heated such that the difference of their length ramains same at ALL termperatures Then (alpha_(1))/(alpha_(2))=(l_(2))/(l_(1))

STATEMENT - 1 : A metallic rod placed upon smooth surface is heated. The strain produced is ZERO. STATEMENT - 2 : Strain is non-zero only when stress is developed in the rod. STATEMENT - 3 : Two metallic rods of length l_(1) and l_(2) and coefficient of linear expansion alpha_(1) and alpha_(2) are heated such that the difference of their length ramains same at ALL termperatures Then (alpha_(1))/(alpha_(2))=(l_(2))/(l_(1))

When a rod is heated but prevented from expanding the stress developed is independent of

STATEMENT 1: A free rod when heated experiences no thermal stress. STATEMENT 2: The rod when heated increases in length.

STATEMENT - 1 : A metallic rod is clamped between two fixed support. The rod is heated but not allowed to bend. Tensile stress is developed in it. STATEMENT - 2 : A metallic rod is fixed between two rigid supports. The rod is heated. The strain produced in the rod is ZERO because there is no change in length STATEMENT - 3 : The practical value of Poisson's ratio lies between 0 and 0.5.

STATEMENT - 1 : A metallic rod is clamped between two fixed support. The rod is heated but not allowed to bend. Tensile stress is developed in it. STATEMENT - 2 : A metallic rod is fixed between two rigid supports. The rod is heated. The strain produced in the rod is ZERO because there is no change in length STATEMENT - 3 : The practical value of Poisson's ratio lies between 0 and 0.5.

When a metal rod is heated it expands because