A steel rod is clamped at its two ends and rests on a fixed horizontal base. The rod is unstrained at 20°C. Find the longitudinal strain developed in the rod if the temperature rises to 50°C. Coefficient of linear expansion of steel = 1.2 × 10–5 °C–1.



Given:

Temperature at which rod is unstrained: T1= 20 ° C
Increased Final Temperature : T2 = 50 ° C
Change in temperature : Δ T = T1 – T2 = 30 °C
Coefficient of linear expansion of steel: α = 1.2 × 10–5 °C–1.
Formula used:
Now we know that formula for linear thermal expansion of a body is:
Where ΔL is the Change in Length and L is the initial length at T1.
Substituting ,



But, Strain is Change in length divided by original length:




Hence, Longitudinal strain developed in the rod is 3.6 x 10


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