Unit I Thermal stress

When a material undergoes a temperature change, the resulting stress is called

• Hydrostatic stress

• Shear stress

• Thermal stress

• Torsional stress

A bar of length L, cross-sectional area A, and coefficient of linear expansion α is heated by ΔT. The longitudinal stress in the bar due to the change in temperature is given by

• σ = αLΔT/A

• σ = αAΔT/L

• σ = LαΔT/A

• σ = AαΔT/L

Factor of safety is defined as the ratio of

• Ultimate stress to working stress

• Working stress to ultimate stress

• Breaking stress to ultimate stress

• Ultimate stress to breaking stress

The ratio of linear stress to the linear strain is called

• Modulus of rigidity

• Modulus of elasticity

• Bulk modulus

• Poisson's ratio

When a body is subjected to two equal and opposite pulls, as a result of which the body tends to extend its length, the stress and strain induced is

• Compressive stress, tensile strain

• Tensile stress, compressive strain

• Tensile stress, tensile strain

• Compressive stress, compressive strain