Question

Thermal stress occurs when:

• A. Temperature is uniform
• B. Expansion is allowed
• C. Expansion is restrained
• D. There is no temperature change

Hint:

Thermal stress is caused by a change in temperature when the material's expansion is restricted. If expansion is free, no stress is developed.

Answer 1

The Correct Option is C

Thermal stress occurs when a material undergoes a change in temperature, but its expansion or contraction is restricted.
- Temperature is uniform does not cause thermal stress by itself, as the material expands uniformly and does not develop stress.
- Expansion is allowed would result in no thermal stress because the material can freely expand or contract without restriction.
- Expansion is restrained leads to thermal stress because the material cannot expand or contract as needed, causing internal forces to develop.
- There is no temperature change would not cause thermal stress, as no temperature-induced deformation would occur.
Thus, thermal stress occurs when expansion is restrained.