Quiznetik

Strength of Materials | Set 5

1. The springs in cars are used to store strain energy.

Correct : B. Incorrect

2. Factor of safety is defined as the ratio of

Correct : A. ultimate stress to working stress

3. When a beam is subjected to a bending moment, the strain in a layer is

Correct : B. directly proportional to

4. In the above question, the normal stress on an oblique section will be maximum, when ? is equal to

Correct : A. 0?

5. The Rankine's constant for a mild steel column with both ends hinged is

Correct : C. 1 ? 7500

6. A tensile test is performed on a mild steel round bar. Its diameter after fracture will

Correct : C. decrease

7. The hoop stress in a thick cylindrical shell is maximum at the inner radius.

Correct : A. True

8. For riveting, the size of hole drilled in plates is

Correct : C. greater than

9. When a shaft is subjected to a twisting moment, every cross-section of the shaft will be under

Correct : C. shear stress

10. The line of intersection of the neutral layer with any normal cross-section of the beam is called neutral axis.

Correct : A. True

11. A reinforced cement concrete beam is considered to be made of

Correct : B. hetrogeneous material

12. The strength of the shaft is judged by the torque transmitted by the shaft.

Correct : A. Yes

13. In a leaf spring the length of all the leaves are equal.

Correct : B. False

14. The ductility of the material

Correct : B. decreases

15. The ratio of linear stress to the linear strain is called

Correct : B. modulus of elasticity

16. The load required to produce a unit deflection in a spring is called

Correct : C. spring stiffness

17. When a thin cylindrical shell is subjected to an internal pressure, there will be

Correct : D. an increase in diameter and length of the shell

18. The design of thin cylindrical shells is based on

Correct : A. hoop stress

19. A column of length (l) with both ends fixed may be considered as equivalent to a column of length

Correct : C. l / 2

20. Resilience is the

Correct : D. none of the above

21. Two closely-coiled helical springs 'A' and 'B' of the same material, same number of turns and made from same wire are subjected to an axial load W. The mean diameter of spring 'A' is double the mean diameter of spring 'B'. The ratio of deflections in spring 'B' to spring 'A' will be

Correct : A. 1 ? 8

22. The neutral axis of the symmetrical beam does not pass through the centroid of the beam.

Correct : B. Disagree

23. The maximum bending moment of a cantilever beam of length l and carrying a uniformly distributed load of w per unit length lies at the middle of its length.

Correct : B. False

24. A body is subjected to a direct tensile stress (?) in one plane. The shear stress is maximum at a section inclined at

Correct : B. 45? to 135?

25. A localised compressive stress at the area of contact between two members is known as

Correct : C. crushing stress

26. The shear stress at the outermost fibres of a circular shaft under torsion is

Correct : C. maximum

27. A shaft of diameter D is subjected to a twisting moment (T) and a bending moment (M). If the maximum bending stress is equal to maximum shear stress developed, then M is equal to

Correct : A. T / 2

28. Which of the following statement is correct?

Correct : C. Rivets are generally specified by its shank diameter

29. A bolt is made to pass through a tube and both of them are tightly fitted with the help of washers and nuts. If the nut is tightened, then

Correct : D. bolt is under tension and tube is under compression

30. The thermal stress

Correct : B. does not depend

31. When a bar is subjected to a change of temperature and its deformation is prevented, the stress induced in the bar is

Correct : D. thermal stress

32. When a material is loaded within elastic limit, the material will regain its shape and size when the load is removed.

Correct : A. Agree

33. When a bar of length l, width b and thickness t is subjected to a pull of P, its

Correct : C. length increases, width and thickness decreases

34. A beam of uniform strength has

Correct : B. same bending stress at every section

35. In the above question, the ratio of stiffness of spring 'B' to spring 'A' will be

Correct : D. 8

36. A load which is spread over a beam in such a manner that it varies uniformly over the whole length of a beam is called uniformly

Correct : B. varying

37. Which of the following statement is wrong?

Correct : C. At the neutral axis of a beam, the bending stress is maximum

38. Which of the following statement is correct?

Correct : B. A uniformly distributed load spreads uniformly over the whole length of a beam.

39. A fixed beam is one which is fixed at

Correct : B. both

40. On one side of a neutral axis of a beam, there is a tensile stress and on the other side of the beam there is a compressive stress

Correct : A. Agree

41. If the magnitude of direct stress and bending stress is equal, then there will be zero stress at one of the extreme ends of a column.

Correct : A. Agree

42. The ratio of the lateral strain to the linear strain is called

Correct : D. Poisson's ratio

43. The bending moment diagram for a cantilever beam of length l and carrying a gradually varying load from zero at the free end and w per unit length at the fixed end is a parabolic curve.

Correct : A. Agree

44. A simply supported beam 'A' of length l, breadth b and depth d carries a central load W. Another beam 'B' of the same dimensions carries a central load equal to 2 W. The deflection of beam 'B' will be

Correct : C. double

45. A simply supported beam 'A' of length l, breadth b and depth d carried a central point load W. Another bream 'B' has the same length and breadth but its depth is doubled. The deflection of beam 'B' will be double as compared to beam 'A'.

Correct : B. Wrong

46. A flitched beam is used to

Correct : C. equalise the strength in tension and compression

47. The volumetric strain is the ratio of the

Correct : D. change in volume to the original volume

48. A concentrated load is one which

Correct : A. acts at a point on a beam

49. A simply supported beam is one which is supported on more than two supports.

Correct : B. False

50. For the above question, the minimum normal stress will be

Correct : A. ? 100 MPa

51. A beam extending beyond the supports is called

Correct : C. overhanging beam

52. Two shafts 'A' and 'B' are made of same material. The shaft 'A' is solid and has diameter D. The shaft 'B' is hollow with outer diameter D and inner diameter D / 2. The strength of hollow shaft in torsion is

Correct : D. 15 ? 16

53. The proof resilience per unit volume of a material is known as modulus of resilience.

Correct : A. True

54. The section modulus of a rectangular section about an axis through its C.G., is

Correct : D. bd2 / 6

55. The energy stored in a body when strained within elastic limit is known as

Correct : C. strain energy

56. According to Euler's column theory, the crippling load for a column of length (l) fixed at both ends is

Correct : C. four times

57. A continuous beam is one which is

Correct : C. supported on more than two supports

58. When two main plates are kept in alignment butting each other and riveted with cover plate on both sides of the main plates with two rows of rivets in each main plate, the joint is known as

Correct : B. double riveted

59. In order to prevent crushing of masonry at the base of the dam, the maximum stress should be

Correct : B. less than

60. The bending moment at a section tends to bend or deflect the beam and the internal stresses resist its bending. The resistance offered by the internal stresses, to the bending, is called

Correct : C. bending stress

61. The resultant stress on an inclined plane which is inclined at an angle ? to the normal cross-section of a body which is subjected to a direct tensile stress (?) in one plane, is

Correct : B. ? cos ?

62. In compression test, the fracture in cast iron specimen would occur along

Correct : B. an oblique plane

63. When there is no increase or decrease in shear force between two points, it indicates that there is no change in the bending moment between these points.

Correct : A. True

64. In a riveted joint, when the number of rivets decreases from the inner most row to outer most row, the joint is said to be

Correct : C. diamond riveted

65. In spring balances, the spring is used

Correct : B. to measure forces

66. When the shear force diagram is a parabolic curve between two points, it indicates that there is a

Correct : D. uniformly varying load between the two points

67. Whenever some external system of forces acts on a body, it undergoes some deformation. As the body undergoes some deformation, it sets up some resistance to the deformation. This resistance per unit area to deformation, is called

Correct : B. stress

68. The point of contraflexure is a point where

Correct : B. bending moment changes sign

69. In the Euler's formula, the value of C for a column with both ends fixed is 4.

Correct : B. Disagree

70. The maximum shear stress is equal to the radius of Mohr's circle.

Correct : A. Correct

71. The stress induced in a body, when suddenly loaded, is

Correct : C. twice

72. A beam encastered at both the ends is called

Correct : B. fixed beam

73. When a cantilever beam is loaded at its free end, the maximum compressive stress shall develop at

Correct : A. bottom fibre

74. A thick pressure vessel is always used for the generation of steam, as it can withstand high pressures.

Correct : B. False

75. Compression members always tend to buckle in the direction of the

Correct : D. least radius of gyration

76. An overhanging beam must overhang on both sides.

Correct : A. Right

77. When a closely-coiled helical spring is subjected to an axial load, it is said to be under

Correct : C. torsion

78. When the shear force diagram between any two points is an inclined straight line, it indicates that there is a uniformly varying load between the two points

Correct : A. Yes

79. The assumption made in the theory of the reinforced cement concrete beam is that

Correct : D. all of the above

80. When a body is subjected to three mutually perpendicular stresses, of equal intensity, the ratio of direct stress to the corresponding volumetric strain is known as

Correct : C. bulk modulus

81. A pressure vessel is said to be a thin shell when the ratio of wall thickness of the vessel to its diameter is

Correct : B. less than

82. The shear force diagram of a cantilever beam of length l and carrying a uniformly distributed load of w per unit length will be

Correct : A. a right angled triangle

83. When a cantilever beam is loaded with concentrated loads, the bending moment diagram will be a

Correct : C. inclined straight line

84. The efficiency of a riveted joint is the ratio of the strength of the joint to the strength of the solid plate.

Correct : A. True

85. Which of the following statement is wrong?

Correct : D. The bulk modulus is the ratio of linear stress to the linear strain.

86. Strain energy is the

Correct : A. energy stored in a body when strained within elastic limits

87. The bending stress in a beam is

Correct : B. inversely proportional to

88. Shear modulus is the ratio of

Correct : D. shear stress to shear strain

89. According to Euler's column theory, the crippling load of a column is given by P = ?2 EI / Cl2. In this equation, the value of C for a column with both ends hinged, is

Correct : C. 1

90. In watches, the spring is used to absorb shocks and vibrations.

Correct : B. No

91. The ratio of shear modulus to the modulus of elasticity for a Poisson's ratio of 0.4 will be

Correct : C. 5 ? 14

92. The shear force at the centre of a simply supported beam with a gradually varying load from zero at both ends to w per metre at the centre, is

Correct : A. zero

93. A column of length (l) with both ends fixed may be considered as equivalent to a column of length

Correct : B. l / 4

94. A spring, when loaded, is permanently distorted and recover its original shape when the load is removed.

Correct : A. Agree

95. In calculating the strength of a riveted joint in tearing, shearing and crushing, the

Correct : B. actual diameter of hole drilled for rivet is used

96. At the neutral axis of a beam

Correct : D. the layers do not undergo any strain

97. The equivalent length, of a given column with given end conditions, is the length of an equivalent column of the same material and cross-section with hinged ends, and having the value of crippling load equal to that of the given column.

Correct : A. True

98. The slenderness ratio is the ratio of

Correct : B. length of column to least radius of gyration

99. In order to know whether a column is long or short, we must know its slenderness ratio.

Correct : A. True

100. The steel bars in a reinforced cement concrete beam are embedded

Correct : B. near the bottom