Quiznetik

Strength of Materials | Set 4

1. A closely-coiled helical spring is cut into two halves. The stiffness of the resulting spring will be

Correct : B. double

2. The deformation of a bar under its own weight is

Correct : B. half

3. A steel bar 2 m long, 20 mm wide and 10 mm thick is subjected to a pull of 2 kN. If the same bar is subjected to a push of 2 kN, the Poission's ratio of the bar in tension will be

Correct : A. equal to

4. The breaking stress is

Correct : B. less than

5. Modulus of rigidity may be defined as the ratio of

Correct : D. shear stress to shear strain

6. A simply supported beam 'A' of length l, breadth b, and depth d carries a central point load W. Another beam 'B' has the same length and depth but its breadth is doubled. The deflection of beam 'B' will be

Correct : B. one-half

7. The limit of eccentricity for no tensile condition for a column of circular section of diameter

Correct : B. d / 8

8. When a rectangular beam is loaded transversely, the zero stress is developed on the neutral axis.

Correct : A. True

9. For no tension condition in the base of a short column of circular section, the line of action of the load should be within a circle of diameter equal to

Correct : C. one-fourth

10. A pressure vessel is said to be a thick shell, when

Correct : D. the ratio of wall thickness of the vessel to its diameter is greater than 1 / 10

11. A uniformly distributed load may be assumed to behave like a point load at the centre of gravity of the load for all sorts of calculations.

Correct : A. Right

12. A riveted joint may fail by

Correct : D. any one of these

13. A column that fails due to direct strss, is called

Correct : A. short column

14. The ultimate tensile stress for mild steel is

Correct : C. more than

15. A load which acts at a point on a beam is not called uniformly distributed load.

Correct : A. Agree

16. Young's modulus may be defined as the ratio of

Correct : C. linear stress to linear strain

17. The thermal or temperature stress is a function of

Correct : D. all of these

18. A section of beam is said to be in pure bending, if it is subjected to

Correct : C. constant bending moment and zero shear force

19. The rivets are made from ductile material.

Correct : A. Yes

20. When there is a sudden increase or decrease in shear force diagram between any two points, it indicates that there is a

Correct : A. point load at the two points

21. A double strap butt joint with equal straps is

Correct : B. always in double shear

22. The ratio of the largest load in a test to the original cross-sectional area of the test piece is called.

Correct : C. ultimate stress

23. Fatigue test is carried out for

Correct : D. all of the above

24. A spring used to absorb shocks and vibrations is

Correct : C. leaf spring

25. The neutral axis of a beam is subjected to

Correct : A. zero

26. When a bar is cooled to -5?C, it will develop

Correct : C. tensile stress

27. If the tearing efficiency of a riveted joint is 50%, then ratio of rivet hole diameter to the pitch of rivets is

Correct : C. 0.5

28. In case of an over-reinforced beam, the depth of actual neutral axis is the same as that of the critical neutral axis.

Correct : B. False

29. The bending moment diagram for a cantilever beam loaded with uniformly distributed load will be a parabolic curve.

Correct : A. Correct

30. The strain energy stored in a body, when suddenly loaded, is

Correct : D. four times

31. When a body is subjected to two equal and opposite pushes, as a result of which the body tends to reduce its length, the stress and strain induced is compressive.

Correct : A. True

32. The neutral axis of the cross-section a beam is that axis at which the bending stress is

Correct : A. zero

33. The stress at which the extension of the material takes place more quickly as compared to the increase in load, is called

Correct : B. yield point

34. The Young's modulus of a material is 125 Gpa and Poissons ratio is 0.25. The modulus of rigidity of the material is

Correct : B. 50 GPa

35. Euler's formula holds good only for

Correct : B. long column

36. A beam supported at its both ends is not a simply supported beam.

Correct : B. False

37. The shear force of a cantilever beam of length / carrying a uniformly distributed load of w per unit length is

Correct : D. wl

38. The shear force at the ends of a simply supported beam carrying a uniformly distributed load of w per unit length is

Correct : C. wl / 2 at one end and - wl / 2 at the other end

39. The shear force diagram for a cantilever beam of length l and carrying a gradually varying load from zero at free end and w per unit length at the fixed end is a

Correct : D. parabolic curve

40. In a riveted joint, when the rivets in the adjacent rows are staggered in such a way that every rivet is in the middle of the two rivets of the opposite row, the joint is said to be diamond riveted.

Correct : B. No

41. The Rankine's formula holds good for

Correct : C. both short and long columns

42. The extremeties of any diameter on Mohr's circle represent

Correct : B. normal stresses on planes at 45?

43. The Poisson's ratio for cast iron varies from

Correct : B. 0.25 to 0.33

44. The centre to centre distance, between two consecutive rivets in a row, is called

Correct : B. pitch

45. The load at which the column just buckles, is known as

Correct : D. any one of these

46. In a watch, the spring is used to store strain energy. This energy is released

Correct : B. to run the watch

47. The product of the tangential force acting on the shaft and its distance from the axis of the shaft (i.e. radius of shaft) is known as

Correct : B. twisting moment

48. If the modulus of elasticity of a material is twice its modulus of rigidity, then the Poisson's ratio of the material is equal to zero.

Correct : A. Correct

49. The shear force diagram for a simply supported beam carrying a uniformly distributed load of w per unit length, consists of

Correct : B. two right angled triangles

50. The columns whose slenderness ratio is less than 80, are known as

Correct : A. short column

51. The bending moment of a cantilever beam of length l and carrying a uniformly distributed load of w per unit length is

Correct : A. zero

52. When a beam is subjected to bending moment, the stress at any point is

Correct : B. directly proportional to

53. A beam of T-section is subjected to a shear force of F. The maximum shear force will occur at the

Correct : C. neutral axis of the section

54. The planes, which carry no shear stress, are known as principal planes.

Correct : A. True

55. A masonry dam may fail due to

Correct : D. any one of the above

56. A thin cylindrical shell of diameter (d) length (l) and thickness (t) is subjected to an internal pressure (p). The longitudinal stress in the shell is

Correct : C. pd / 4t

57. The proof resilience is the maximum strain energy which can be stored in a body

Correct : A. Yes

58. A pressure vessel is said to be a thin shell when it is made of thin sheets.

Correct : B. Disagree

59. The distance between the centres of rivets in adjacent rows of zig-zag riveted joint, is called back pitch.

Correct : B. False

60. A cantilever beam is one which is

Correct : B. fixed at one end and free at the other end

61. The buckling load for a given column depends upon

Correct : D. all of the above

62. If percentage reduction in area of a certain specimen made of material 'A' under tensile test is 60% and the percentage reduction in area of a specimen with same dimensions made of material 'B' is 40%, then

Correct : A. the material A is more ductile than material B

63. The springs in brakes and clutches are used to

Correct : A. to apply forces

64. The maximum shear stress is

Correct : C. one-half

65. When a column is subjected to an eccentric load, the stress induced in the column will be

Correct : D. direct and bending stress both

66. In a thick cylindrical shell subjected to an internal pressure (p), the tangential stress is always a tensile stress where as the radial stress is a compressive stress

Correct : A. Correct

67. The bending moment of a cantilever beam of length l and carrying a uniformly distributed load of w per unit length is

Correct : D. wl2 / 2

68. When a rectangular beam is loaded longitudinally, the shear force develops on the top layer.

Correct : B. Disagree

69. A thin cylindrical shell of diameter (d), length (l) and thickness (t) is subjected to an internal pressure (p). The hoop stress in the shell is

Correct : B. pd / 2t

70. A bar of copper and steel form a composite system, which is heated to a temperature of 40?C. The stress induced in the copper bar will be

Correct : B. compressive

71. When one plate overlaps the other and the two plates are riveted together with two rows of rivets, the joint is known as

Correct : B. double riveted lap joint

72. A body is subjected to a tensile stress of 1200 MPa on one plane and another tensile stress of 600 MPa on a plane at right angles to the former. It is also subjected to a shear stress of 400 MPa on the same planes. The maximum normal stress will be

Correct : D. 1400 MPa

73. A leaf spring is supported at the

Correct : B. centre and loaded at the ends

74. In a simple bending of beams, the stress in the beam varies

Correct : A. linearly

75. The unit of stress in S.I. units is

Correct : D. any one of these

76. In a simply supported beam carrying a uniformly distributed load w per unit length, the point of contraflexure

Correct : D. does not exist

77. When a rectangular beam is loaded transversely, the maximum tensile stress is developed on the

Correct : A. top layer

78. The unit of Young's modulus is same as that of stress.

Correct : A. True

79. The deformation per unit length is called

Correct : D. strain

80. In case of eccentrically loaded struts

Correct : C. composite section

81. The compression test is carried on

Correct : B. brittle

82. The point of contraflexure occurs in

Correct : C. overhanging beams

83. The shear force at a certain point on a beam changes sign form +ve value to -ve value or vice versa. The bending moment at that point will be zero.

Correct : B. False

84. When a body is subjected to two equal and opposite forces, acting tangentially across the resisting section, as a result of which the body tends to shear off across the section, the stress and strain induced is

Correct : D. shear stress, shear strain

85. The formation of the bar per unit length in the direction of the force is known as

Correct : A. linear strain

86. In a beam where shear force changes sign, the bending moment will be

Correct : C. maximum

87. When a change in length takes place, the strain is known as

Correct : A. linear strain

88. The factor of safety is always more than unity.

Correct : A. Correct

89. For long columns, the value of buckling load is

Correct : B. less than

90. The capacity of a strained body for doing work on the removal of the straining force, is called

Correct : B. resilience

91. A body is subjected to a direct tensile stress of 300 Mpa in one plane accompanied by a simple shear stress of 200 Mpa. The maximum normal stress will be

Correct : D. 400 MPa

92. A beam which is fixed at one end and free at the other is called

Correct : D. cantilever beam

93. The product of Young's modulus (E) and moment of inertia (I) is known as

Correct : C. flexural rigidity

94. The unit of modulus of elasticity is same as those of

Correct : D. stress, pressure and modulus of rigidity

95. 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

Correct : C. tensile stress, tensile strain

96. The total strain energy stored in a body is termed as

Correct : A. resilience

97. The stiffness of a closely-coiled helical spring is

Correct : B. inversely

98. For biaxial stress, the planes of maximum shear are at right angles to each other and are inclined at 45? to the principal planes.

Correct : A. True

99. The perpendicular distance between the centre lines of the successive rows, is called pitch.

Correct : B. Disagree

100. In a thick cylindrical shell subjected to an internal pressure (p), the maximum radial stress at the inner surface of the shell is

Correct : C. ? p (compressive)