Thermal Stress

Q.

In the given figure, a rod is free at one end and other and is fixed. When we change the temperature of rod by $\Delta$T, then strain produced in the rod will be

1. $\alpha \Delta T$

2. zero
3. information incomplete

4. $\frac{1}{2}\alpha \Delta T$

Q.

A wire of cross-sectional area A at temperature t is held taut with a negligible tension between two rigid supports. If the wire is cooled to a temperature $(t-\Delta t)$, what tension is developed in the wire? The coefficient of linear expansion is $\alpha$ and Young's modulus of the wire is Y.

1. $YA\alpha \Delta t$

2. $\frac{Y\alpha \Delta t}{A}$

3. $\frac{A\alpha \Delta t}{Y}$

4. $\frac{YA}{\alpha \Delta T}$