Question

In a composite bar, under what conditions is the strain on both the bars equal?

• A. When both bars contract equally
• B. When both bars are subjected to same temperature change
• C. When both bars are subjected to same load
• D. When both bars have the same surface area

Answer 1

Answer:

A. When both bars contract equally

A composite bar is made of different materials and both bars strain together under external load. The strain in both bars will be the same when both bars contract equally. The total external load on the bar is equal to the sum of the loads carried by different materials. Strain will be independent of surface area and both materials used in the composite will have different coefficients of thermal expansion