Topic: Strength of Materials
A bar of bronze and a bar of steel are placed between two immovable supports, A and B as shown in the figure. The physical constants are: (where L = length of bars, A = cross-sectional area, $\alpha$ = linear co-efficient of thermal expansion, E = Young's modulus). The stresses in the steel & bronze, when temperature drops by 50°C is
- A. Tension
- B. Compression
- C. Shear
- D. None of these
Answer: A. Tension
Explanation: When the temperature drops, the bars tend to contract. However, because they are placed between two immovable (rigid) supports, the supports prevent this free contraction. This restriction of the natural thermal shortening induces tensile stresses in both the steel and bronze bars.