Strength of Materials(1-20)

1.Modulus of rigidity is defined as the ratio of-shear stress to shear strain

2.If the Young's modulus of elasticity of a material is twice its modulus of rigidity, then the Poisson's ratio of the material is-zero

3.Limit of proportionality depends upon-type of material

4.For an isotropic, homogeneous and elastic material obeying Hooke's law, number of independent elastic constants is-2

5.In a thin cylindrical shell, the ratio of longitudinal stress to hoop stress is-2

6.If all the dimensions of a prismatic bar are doubled, then the maximum stress

produced in it under its own weight will-increase to two times

7.The relationship between Young's modulus of elasticity E, bulk modulus K and

Poisson's ratio u is given by-E = 3 K ( l - 2 u )

8.Limiting values of Poisson's ratio are-(- 1 and 0.5)

9.The elongation of a conical bar under its own weight is equal to-one third that of a prismatic bar of same length

10.If a material has identical properties in all directions, it is said to be-isotropic

11. Two bars of different materials are of the same size and are subjected to same tensile forces. If the bars have unit elongations in the ratio of 4 : 7, then the

ratio of moduli of elasticity of the two materials is-7:4

12. A prismatic bar of volume V is subjected to a tensile force in longitudinal direction. If Poisson's ratio of the material is μ and longitudinal strain is e, then the final volume of the bar becomes-

13.If a composite bar of steel and copper is heated, then the copper bar will be under-compression

14.Effective length of a weld is equal to-overall length - 2 x weld size

15. Size of a right angled fillet weld is given by-0.414 x throat thickness

16. The effective length of a fillet weld designed to transmit axial load shall not be

less than-4 x size of weld

17. Size of fillet weld with unequal legs is equal to-smaller leg length

18.Weakest section in a fillet weld is-throat of the fillet

19.Effective throat thickness of a fillet weld is-a function of the angle between fusion faces

20.If b is the width of the plate and d is the diameter of rivet, then the efficiency of a riveted joint having diamond riveting is given by-((b-d)/b)