Quiznetik

Strength of Materials | Set 2

1. In a tensile test of specimen,the ratio of maximum load to the original cross sectional area of test piece is called

Correct : B. ultimate stress

2. In a body, thermal stress is one which arises because of the existence of

Correct : B. temperature gradient

3. A localized compressive stress at the area of contact between the two surfaces is called as

Correct : C. bearing stress

4. The ratio between change in volume to original volume of body is called ………… strain.

Correct : D. volumetric

5. There is always a limiting value of load up to which the strain totally disappears on the removal of load; the stress corresponding to this load is called…………

Correct : A. elastic limit

6. Robert Hooke discovered experimentally that within elastic limit

Correct : C. stress/strain = constant

7. When a tensile or compressive force (P) acts on a body, the change in its length is given by

Correct : A. pl/ae

8. Modulus of elasticity is defined as the ratio of

Correct : B. linear stress to linear strain

9. The ratio of linear strain to lateral strain is known as

Correct : D. none of above

10. The ratio of lateral strain to linear strain is known as

Correct : C. poisson's ratio

11. The relation between E (modulus of elasticity) and C (modulus of rigidity) is given by

Correct : B. e =2 c (1+µ)

12. The relation between E (modulus of elasticity) and K (bulk modulus of elasticity) is given by

Correct : C. e=3k(1-2µ)

13. Relation between E, K and C is given by

Correct : A. e=9kc/(3k+c)

14. Which of the following statement is incorrect?

Correct : C. hooke's law holds good up to the breaking point

15. When a bar is subjected to a change of temperature and its deformation is prevented, which of the following stress is induced?

Correct : A. thermal stress

16. Temperature stress developed in a bar depends on which of the following?

Correct : D. all of above

17. The temperature strain in a bar is ……………..proportional to the change in temperature.

Correct : A. directly

18. …………….Strain is the deformation of the bar per unit length in the direction of force.

Correct : D. linear

19. Strain in a direction at right angles to the direction of applied force is known as

Correct : A. lateral strain

20. A localized compressive stress at the area of contact between two members is known as ……………..stress.

Correct : B. crushing

21. A material with identical properties in all directions is known as

Correct : A. homogeneous

22. The units of stress in the SI system are

Correct : B. n/m2

23. In a lap riveted joint the rivets are mainly subjected to --------------stress

Correct : A. shear

24. The resistance to deformation of a body per unit area is known as

Correct : A. stress

25. stress developed due to external force in an elastic material

Correct : B. does not depend on elastic constants

26. Strain is defined as deformation per unit

Correct : B. length

27. The units of modulus of elasticity are the same as of

Correct : D. any of the above

28. Approximate value of Young's modulus for mild steel is

Correct : C. 205gpa

29. 1MPa is equal to

Correct : B. 1 n/mm2

30. Temperature stress is a function of

Correct : D. all of the above

31. Factor of safety is defined as ratio of

Correct : A. ultimate stress to allowable stress

32. The stress at which elongation of a material is quite large as compared to increase in load is known as

Correct : B. yield point

33. Poisson's ratio is defined as ratio of

Correct : B. transverse strain to axial strain

34. During free expansion due to temperature rise or fall,

Correct : A. no stress is developed

35. For any material, the maximum value of E in terms of G is E =

Correct : C. 3g

36. For any material, the minimum value of E in terms of G is E

Correct : B. 2g

37. Two materials are having modulus of elasticity, modulus of rigidities and bulk modulus as (E1, E2), (C1, C2), and (K1, K2). The modulus ratio is given by

Correct : C. e1/e2

38. The force

Correct : A. stiffness

39. Thermal stress is developed in a temperature when _.

Correct : B. not allowed to expand freely

40. Which of the following beams will develop thermal stress when subjected to a change in temperature ?

Correct : B. beam with hinges at both ends

41. Change in length of a rod due to change in depend on _.

Correct : C. modulus of elasticity

42. A steel strip is welded to a copper strip of the same dimensions along the length. The coefficient of thermal expansion for copper is greater than that for steel. If temperature is increased, ___ .

Correct : B. steel has tensile stress

43. While punching a hole in a metal sheet using a punch, stress is developed in the metal sheet.

Correct : C. shear

44. While punching a hole in a metal sheet using a punch, stress is developed in the Punch.

Correct : A. normal compressive

45. Poisson’s ratio for rubber is……that for steel.

Correct : A. larger than

46. For a certain material, the Poisson's ratio is 0. The relation between modulus of elasticity E and the bulk modulus K is E = ____ _.

Correct : B. 3k

47. For a certain material, E = 3K . The value of Poisson's ratio for the material will be__ _.

Correct : A. 0

48. Modulus of rigidity is defined as the ratio of

Correct : B. shear stress to shear strain

49. 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

Correct : D. zero

50. Limit of proportionality depends upon

Correct : C. type of material

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

Correct : A. 2

52. In a thin cylindrical shell, the ratio of longitudinal stress to hoop stress is

Correct : C. 2

53. If all the dimensions of a prismatic bar are doubled, then the maximum stress produced in it under its own weight will

Correct : C. increase to two times

54. The relationship between Young's, modulus of elasticity E, bulk modulus K and Poisson's ratio u is given by

Correct : C. E = 3K(l-2u)

55. Limiting values of Poisson's ratio are

Correct : A. - 1 and 0.5

56. The elongation of a conical bar under its own weight is equal to

Correct : C. one third that of a prismatic bar of same length

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

Correct : B. isotropic

58. 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

Correct : A. 7:4

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

Correct : C. (l + e)(l-ne)2V

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

Correct : B. compression

61. Effective length of a weld is equal to

Correct : C. overall length - 2 x weld size

62. Size of a right angled fillet weld is given by

Correct : B. 0.414 x throat thickness

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

Correct : B. 4 x size of weld

64. Size of fillet weld with unequal legs is equal to

Correct : A. smaller leg length

65. Weakest section in a fillet weld is

Correct : A. throat of the fillet

66. Effective throat thickness of a fillet weld is

Correct : C. a function of the angle between fusion faces

67. According to Unwin's formula, the dia¬meter of rivet in mm to suit the t mm thickness of plate is given by

Correct : B. 6Vt

68. A flat carrying a pull of 69C kN is con-nected to a gusset plate using rivets. If the pulls required to shear the rivet, to crush the rivet and to tear the plate per pitch length are 68.5 kN, 46 kN and 69 kN respectively, then the number of rivets required is

Correct : C. 15

69. If the rivet value is 16.8 kN and force in the member is 16.3 kN, then the number of rivets required for the connection of the member to a gusset plate is

Correct : B. 2

70. At a point in a strained body carrying two unequal unlike principal stresses pi and p2 (Pi > P2X the maximum shear stress is given by

Correct : D. (p, + p2)/2

71. If a point in a strained material is subjected to equal normal and tangential stresses, then the angle of obliquity is

Correct : B. 45°

72. If a prismatic member with area of cross-section A is subjected to a tensile load P, then the maximum shear stress and its inclination with the direction of load respectively are

Correct : B. P/2Aand45°

73. The sum of normal stresses is

Correct : A. constant

74. The radius of Mohr's circle for two equal unlike principal stresses of magnitude p is

Correct : A. p

75. Shear stress on principal planes is

Correct : A. zero

76. The state of pure shear stress is produced by

Correct : A. tension in one direction and equal compression in perpendicular direction

77. According to Rankine's hypothesis, the criterion of failure of a brittle material is

Correct : A. maximum principal stress

78. Maximum bending moment in a beam occurs where

Correct : D. shear force changes sign

79. Rate of change of bending moment is equal to

Correct : D. rate of loading

80. The diagram showing the variation of axial load along the span is called

Correct : A. shear force diagram

81. The difference in ordinate of the shear curve between any two sections is equal to the area under

Correct : D. load curve between these two sections plus concentrated loads applied between the sections

82. The variation of the bending moment in the portion of a beam carrying linearly varying load is

Correct : C. cubic

83. The maximum bending moment due to a moving load on a fixed ended beam occurs

Correct : A. at a support

84. A cantilever beam AB of length 1 carries a concentrated load W at its midspan C. If the free end B is supported on a rigid prop, then there is a point of contraflexure

Correct : A. between A and C

85. A prismatic beam fixed at both ends carries a uniformly distributed load. The ratio of bending moment at the supports to the bending moment at mid-span is

Correct : D. 2.0

86. A beam of overall length 1 with equal overhangs on both sides carries a uniformly distributed load over the entire length. To have numerically equal bending moments at centre of the beam and at supports, the distance between the supports should be

Correct : C. 0.5861

87. A prismatic beam of length 1 and fixed at both ends carries a uniformly distributed load. The distance of points of contraflexure from either end is

Correct : B. 0.2111

88. A simply supported beam of length 1 carries a load varying uniformly from zero at left end to maximum at right end. The maximum bending moment occurs at a distance of

Correct : A. 1/V3 from left end

89. A portion of a beam between two sections is said to be in pure bending when there is

Correct : A. constant bending moment and zero shear force

90. The ratio of width to depth of a strongest beam that can be cut out of a cylindrical log of wood is

Correct : B. 1/V2

91. Of the several prismatic beams of equal lengths, the strongest in flexure is the one having maximum

Correct : B. section modulus

92. Of the two prismatic beams of same material, length and flexural strength, one is circular and other is square in cross-section. The ratio of weights of circular and square beams is

Correct : A. 1.118

93. A flitched beam consists of a wooden joist 150 mm wide and 300 mm deep strengthened by steel plates 10 mm thick and 300 mm deep one on either side of the joist. If modulus of elasticity of steel is 20 times that of wood, then the width of equivalent wooden section will be

Correct : D. 550 mm

94. A beam of rectangular cross-section is 100 mm wide and 200 mm deep. If the section is subjected to a shear force of 20 kN, then the maximum shear stress in the section is

Correct : D. 1.5 N/mm2

95. A beam of square cross-section with side 100 mm is placed with one diagonal vertical. If the shear force acting on the section is 10 kN, the maximum shear stress is

Correct : B. 1.125 N/mm2

96. A prismatic bar when subjected to pure bending assumes the shape of

Correct : D. arc of a circle

97. A beam of triangular cross section is placed with its base horizontal. The maximum shear stress intensity in the section will be

Correct : C. above the neutral axis

98. A beam of uniform strength has at every cross-section same

Correct : B. bending stress

99. For no torsion, the plane of bending should

Correct : B. pass through shear centre of section

100. Two beams, one of circular cross-section and other of square cross-section, have equal areas of cross-section. If subjected to bending

Correct : B. square section is more economical