Quiznetik

Strength of Materials | Set 1

1. Hooke's law holds good up to..

Correct : B. proportional limit

2. The ratio of linear stress to linear strain is called as

Correct : A. modulus of elasticity

3. The modulus of elasticity for mild steel is approximately equal to

Correct : D. 210 kn/mm2

4. When the material is loaded with elastic limit , then the stress is ……. to strain.

Correct : B. directly proportional

5. The ratio of ultimate tensile stress to the design stress is known as

Correct : C. factor of safety

6. An aluminum member is designed based on

Correct : A. yield stress

7. The poisson's ratio for Cast Iron varies from

Correct : C. 0.23 to 0.27

8. The Poisson’s ratio for steel varies from

Correct : B. 0.25 to 0.33

9. The property of material to absorb shock energy without failure is known as….

Correct : B. toughness

10. Young’s modulus of Elasticity for perfectly rigid body is….

Correct : C. infinity

11. The stress is….

Correct : C. tensor

12. The Poisson’s ratio for perfectly rigid body is

Correct : B. 0

13. Shearing strain is represented by………

Correct : B. angle of shear

14. Greater the value of modulus of elasticity more…is the material

Correct : B. elastic

15. Stress does not depand upon

Correct : C. modulus of elasticity

16. stress does not depend upon

Correct : C. change in length

17. modulus of elasticity for rubber is ……than that for steel.

Correct : C. smaller than

18. Change in length of the rod due to change in temperature depends on…

Correct : D. all of above

19. The value of K for perfectly rigid body is

Correct : D. infinity

20. Time dependent permanent deformation is called as

Correct : C. creep

21. Figure out the odd point in the following

Correct : D. fracture point

22. Engineering stress strain curve and true stress strain curve are equal up to

Correct : C. yield point

23. Shape of true stress strain curve of material depends upon

Correct : D. all of the above

24. Within elastic limit in a loaded material, stress is

Correct : B. directly proportional to strain

25. The ratio of linear stress to linear strain is known as

Correct : D. modulus of elasticity

26. the ratio of lateral strain to linear strain is known as

Correct : A. poisson's ratio

27. The ratio of shear stress to shear strain is known as

Correct : C. modulus of rigidity

28. The ratio of normal stress of each face of a solid cube to volumetric strain is called

Correct : B. bulk modulus

29. Hooke's law holds good up to

Correct : A. proportional limit

30. The property of material by virtue of which a body returns to its original shape after removal of load is known as

Correct : C. elasticity

31. The work done in producing strain on a material per unit volume is called

Correct : A. resilience

32. The property of material by virtue of which a material can be beaten into plates is called

Correct : B. malleability

33. The Combined effect of external forces acting on body is called

Correct : C. load

34. ………….Load is one which is considered to act at a point.

Correct : C. point

35. The internal resistance which the body offers to meet the load or external force is called

Correct : A. stress

36. The Unit of stress in SI unit is

Correct : D. all of above

37. ……….represents the resistance developed by a unit area of cross section.

Correct : A. unit stress

38. Simple stress is often called

Correct : A. direct stress

39. The deformation per unit length is called……….

Correct : A. strain

40. If L and dL are are length and change in length respectively, then strain is equal to

Correct : A. dl/l

41. If V is the volume of a rectangular bar subjected to a three dimensional stress state and the Poisson's ratio for the material is 0.5, the change in volume of the bar will be __ _.

Correct : D. 0

42. For material Poisson’s ratio is 0.25. Relation between E and G will be

Correct : D. 2.5g

43. The modulus of elasticity of a material is 210 GPa and its Poisson's ratio is 0.4. The modulus of rigidity of the material is

Correct : B. 75

44. The value of factor of safety is always

Correct : A. >1

45. The value of margin of safety is always

Correct : D. >0

46. If the working load is one third of the ultimate load, the factor of safety is

Correct : B. 3

47. If 1 is subtracted from the ratio of yield stress to working stress the quantity obtained is known as

Correct : A. margin of safety

48. Stress does not depend upon

Correct : C. change in length

49. Stress does not depend upon

Correct : C. modulus of elasticity

50. A metal plate of length L and width b has a circle drawn on it. If it is subjected to a compressive stress acting along its width, the circle will

Correct : C. become ellipse with major axis along its length

51. If D is the diameter of the sphere, then volumetric strain is equal to

Correct : C. three times the strain of diameter

52. If L be the length and D be the diameter of cylindrical rod, then volumetric strain of the rod is equal to

Correct : C. strain of length plus twice the strain of diameter

53. the extension per unit length of the rod due to suddenly applied load as compare to same load gradually applied to same rod is

Correct : B. double

54. The tensile force at a distance y from support in a vertical hanging bar of length L whch carries a load P at the bottom is equal to---- where w = weight per unit length

Correct : C. p+w(l-y)

55. Total elongation produced in a bar due to its self weight is given by……….. Where ρ is the density of material in kg/m3

Correct : B. 9.81ρl2/2e

56. The elongation of circular tapered rod is given by…………. Where P=axial pull and d1, d2= diameters at two ends.

Correct : A. 4pl/πed1d2

57. If a bar of length L m extends by l mm under load W, the strain is

Correct : C. 0.001 l/l

58. Four wires of same material are applied the same load. In which of the following cases, the elongation will be maximum (length, diameter)?

Correct : A. 2m, 1mm

59. If ES = 3 EA , the stress in steel of a composite bar made of aluminium and steel strips each having a cross sectional area of 300 mm2 and subjected to an axial load of 12 kN

Correct : C. 30mpa

60. The modulus of rigidity in terms of modulus of elasticity is given by

Correct : B. e/2(1+γ)

61. The modulus of elasticity in terms of bulk modulus is given by

Correct : D. 3k(1-2γ)

62. The ratio of Young's modulus and bulk modulus is given by

Correct : D. 3(1-2γ)

63. The modulus of elasticity in terms of bulk modulus and modulus of rigidity is given by

Correct : A. 9kg/(3k+g)

64. For a Poisson's ratio of 0.4 for a material the ratio of shear modulus of elasticity to modulus of rigidity is

Correct : D. 5/14

65. A material has modulus of rigidity equal to 0.4x105 N/mm2 and Bulk modulus equal to 0.95 x105 N/mm2 The Young’s modulus value in GPa is..

Correct : B. 105

66. A bar of 30 mm diameter is subjected to an axial force 280 KN length of bar is 400 m and E= 200GPa. Determine volumetric strain if m=4.

Correct : B. 9.9 x 10-4

67. A rail 20 m long is prevented from expansion at both end . If the temperature is raised by 30 0C, Stress induced in rail is.. E=200 Gpa,α =12x10-6/°C

Correct : C. 72mpa

68. A tensile material is having Young’s modulus 2.1 x105 N/mm2 and modulus of Rigidity is 0.82 x105 N/mm2. The value of Bulk Modulus is ..

Correct : B. 1.6 x105 n/mm2

69. A steel rod of length is manufactured at a temperature 200C and its temperature increases upto 1350C.What are thermal stresses induced? E=200Gpa,α=12*10-6/0C

Correct : D. 276mpa

70. A steel rod of 3m is manufactured at 250C the temperature of rod is increases to 1250C. If free expansion is 3.6mm, what is the temperature stresses produced if 1.5mm expansion is permitted?

Correct : D. 140mpa

71. A steel rod of 3m length is manufactured at 250C the temperature of this rod increases to 1250C. What is the free expansion? Take E=200Gpa, α=12*10-6/0C,diameter=12mm

Correct : D. 3.6mm

72. A steel tube (E = 200 GPa) has an internal diameter of 40 mm thickness 10 mm and a length of 2 m. If it is subjected to an axial pull of 80 kN, the stress in the tube will be __ _MPa.

Correct : B. 50.13

73. A steel tube (E= 200Gpa) has an internal diameter of 40 mm, thickness 10 mm and a length of 2 m. If it is subjected to an axial pull of 80 kN, the change in length of the tube will be __ _mm.

Correct : B. 0.5

74. The axial force in the portion AB of the member shown in Fig. 1.1 is kN.

Correct : A. 50

75. If the member shown in Fig. 1.1 has a square cross section of 25 mm 25 mm and E = 200 GPa, the change in length of portion AB is              mm.

Correct : A. 0.24

76. The axial force in the portion BC of the member shown in Fig. 1.1 is kN.

Correct : D. -40

77. If the member shown in Fig. 1.1 has a square cross section of 25 mm 25 mm and E = 200 GPa, the change in length of portion CD is ------mm

Correct : B. -0.16

78. The axially loaded composite rod shown in Fig. 1.2 has a uniform cross- sectional area of 500 mm 2 . The modulii of elasticity are Est = 200 GPa, Eal = 70 GPa and Ecu = 120 GPa. The change in length of CD is mm.

Correct : A. 0.15

79. The axially loaded composite rod shown in Fig. 1.2 has a uniform cross- sectional area of 500 mm 2 . The modulii of elasticity are Est = 200 GPa, Eal = 70 GPa and Ecu = 120 GPa. The change in length of the composite rod is mm.

Correct : B. -0.95

80. For the stepped rod shown in Fig. 1.3, the stress is maximum in .

Correct : C. steel

81. For the stepped rod shown in Fig. 1.3,the in .

Correct : A. aluminum

82. A steel bar ABC (E = 200 GPa) is 1 m long. For AB = 0.7 m, it has cross section P area of 500 mm2 and for BC = 0.3 m the cross section area is 400 mm2. The bar is subjected to an axial pull of 100 kN. The stress is maximum in ___ _

Correct : B. bc

83. A stepped bar of steel consists of a pmormtion with cross section area 500 mm2 connected to a portion with cross section area 1000 2. Each portion has a length of 1 m. The modulus of elasticity of steel is 200 GPa. The maximum elongation of the bar by applying an axial tensile force at the ends without exceeding a stress of 100 MPa is    mm.

Correct : B. 0.75

84. The change in length of a rod of uniform circular cross section was found to be 2 mm for some applied force. The change in length of a rod of the same material and length but of half the diameter subjected to the same force will be Mm

Correct : D. 4

85. A strip of steel (E = 200 GPa, 0.25) has a length of 1 m, width of 200 mm and thickness of 10 mm. A line of length 1 m is drawn parallel to its length on one of its side surfaces. When the strip is subjected to an axial tensile force of 100 kN, the length of the line will be                  mm.

Correct : B. 1000.25

86. The change in length of a rod of uniform cross section was found to be 2 mm for some applied force. The change in length of a rod of the same material and length but of twice the cross section area subjected to the same force will be__ mm.

Correct : A. 1

87. Two rods have uniform cross section areas in the ratio 1 : 2 and are subjected to axial tensile forces with magnitudes in the ratio 2 : 1. The stresses induced in the two rods will be in the ratio ____ _.

Correct : D. 4 : 1

88. Two rods have uniform cross section areas in the ratio 1 : 2 and are subjected to axial tensile forces with magnitudes in the ratio 1 : 2. The stresses induced in the two rods will be in the ratio ____ _.

Correct : C. 1:1

89. Two rods have uniform cross section areas in the ratio 1 : 2 and are subjected to axial tensile forces of the same magnitude. The stresses induced in the two rods will be in the ratio __ _ .

Correct : B. 2 : 1

90. If an axial force of 15 kN is applied to a rod of 25 mm diameter, length 300 mm, the change in length of the rod was observed to be 0.045 mm. The modulus of elasticity of the material is 200 GPa. The strain in the rod will be ____ _.

Correct : B. 1.5*10-4

91. If an axial force of 1 kN is applied to a rod of 100 mm cross section area produces change in length of 1 mm over a length of 12 m, the modulus of elasticity of the material will be---------

Correct : D. 120gpa

92. If an axial force of 1 kN is applied to a rod of 100 mm2 cross section area, length 5 m and the modulus of elasticity of the material is 100 GPa, the change in length of the rod will be ___ .

Correct : C. 0.5mm

93. The longitudinal stress developed in a rod of cross section area 50 mm2 is 100 MPa. The force acting along its axis is -------

Correct : D. 5.5kn

94. If an axial force of 1 kN is applied to a steel rod of 100 mm2 cross section area, the stress in it will be ___ .

Correct : A. 10mpa

95. Two equal and opposite forces of magnitude 10 kN are applied at the ends of a steel wire to increase its length. The internal force in the wire will be-----KN

Correct : B. 10

96. The value of factor of safety is always __ _.

Correct : A. >1

97. The value of margin of safety is always __ _.

Correct : D. =0

98. The radius of wire stretched by a load is doubled, then its Modulus of elasticity will be..

Correct : D. unaffected

99. The factor of safety depends on i)Magnitude of external force ii) Properties of material iii) Dimension of the component iv) All of the above

Correct : D. iv

100. The thermal stress is given by where α = coeffeicient of linear expansion T = Rise in temperature

Correct : A. eαt