strength of materials mechanical engineering Mcqs
51. A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal__________________?
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A. metal is twice as dense as unknown fluid

B. density of metal cant be determined

C. metal is twice as dense as water

D. metal will float in water

E. none of the above

52. The effort required to lift a load W on a screw jack with helix angle a and angle of friction <j) is equal to__________________?
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A. Wsin(a + )

B. Wcos(a + )

C. Wtan(a-)

D. Wtan(a + )

E. W (sin a + cos ).

53. Percentage reduction of area in performing tensile test on cast iron may be of the order of__________________?
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A. 50%

B. 0%

C. 15%

D. 25%

E. 60%.

54. Efficiency of a riveted joint is the ratio of its strength (max. load it can resist without failure) to the strength of the unpunched plate in_________________?
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A. none of the above

B. any one of the above

C. compression

D. tension

E. bearing

55. The C.G. of a solid hemisphere lies on the central radius 3r_________________?
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A. at distance from the plane base 3r

B. at distance from the plane base 3r

C. at distance from the plane base

D. at distance from the plane base or

E. at distance from the plane base 3r

56. The safe twisting moment for a compound shaft is equal to the _________________?
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A. minimum calculated value

B. mean value

C. maximum calculated value

D. none of the above

E. extreme value

57. True stress-strain curve for materials is plotted between__________________?
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A. load/instantaneous area and instantaneous area/original area

B. load/original cross-sectional area and change in length/original length

C. none of the above

D. load/instantaneous cross-sectional area original area and log

E. load/instantaneous cross-sectional area and change in length/original length

58. If a part is constrained to move and heated, it will develop ____________________?
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A. principal stress

B. compressive stress

C. tensile stress

D. no stress

E. shear stress

59. The property of a material which allows it to be drawn into a smaller section is called________________?
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A. drawabihty

B. malleability

C. plasticity

D. ductility

E. elasticity

60. Which of the following is the locus of a point that moves in such a manner that its distance from a fixed point is equal to its distance from a fixed line multiplied by a constant greater than one_______________?
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A. ellipse

B. hyperbola

C. parabola

D. none of the above

E. circle

61. The stress necessary to initiate yielding is_________________?
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A. greater than that necessary to stop it

B. considerably lesser than that necessary to continue it

C. equal to that necessary to stop it

D. lesser than that necessary to stop it

E. considerably greater than that necessary to continue it
62. The co-efficient of friction depends upon _________________?
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A. nature of surfaces

B. ail of the above.

C. A. and B. above

D. area of contact

E. shape of the surfaces

63. The materials which exhibit the same elastic properties in all directions are called______________?
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A. isentropic

B. homogeneous

C. isotropic

D. inelastic

E. visco-elastic.

64. If rain is falling in the opposite direction of the movement of a pedestrain, he has to hold his umbrella ________________________?
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A. less inclined when standing

B. more inclined when moving

C. more inclined when standing

D. less inclined when moving

E. none of the above

65. A particle inside a hollow sphere of radius r, having coefficient of friction -rr can rest upto height of___________________?
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A. r/2

B. r/A

C. r/%

D. 0.134 r

E. 3r/8

66. A single force and a couple acting in the same plane upon a rigid body_________________?
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A. are equivalent

B. cannot balance each other

C. none of the above

D. balance each other

E. produce moment of a couple

67. A cylindrical section having no joint is known as ____________________?
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A. jointless section

B. seamless section

C. homogeneous section

D. manufactured section

E. perfect section

68. The value of Poissons ratio for steel is between_________________?
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A. 3 to 4

B. 0.25 to 0.33

C. 0.01 to 0.1

D. 0.4 to 0.6

E. 0.23 to 0.27

69. The algebraic sum of moments of the forces forming couple about any point in their plane is__________________?
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A. equal to the moment of the couple

B. constant

C. both of above are correct

D. both of above are wrong

E. none of the above

70. In a tensile test on mild steel specimen, the breaking stress as compared to ultimate tensile stress is_________________?
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A. same

B. less

C. more/less depending on composition

D. may have any value

E. more

71. The ratio of lateral strain to the linear strain within elastic limit is known as_______________?
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A. bulk modulus

B. modulus of elasticity

C. modulus of rigidity

D. Youngs modulus

E. Poissons ratio
72. During a tensile test on a specimen of 1 cm cross-section, maximum load observed was 8 tonnes and area of cross-section at neck was 0.5 cm2. Ultimate tensile strength of specimen is___________________?
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A. none of the above

B. 22 tonnes/cm2

C. 4 tonnes/cm2

D. 8 tonnes/cm2

E. 16 tonnes/cm2

73. If n = number of members andy = number of joints, then for a perfect frame, n =________________?
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A. 2/ -4

B. 2/-3

C. j-2

D. 3/-2

E. 2j-l

74. A beam is loaded as cantilever. If the load at the end is increased, the failure will occur ___________________?
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A. anywhere

B. in the middle

C. at the tip below the load

D. none of the above

E. at the support

75. In a belt drive, the pulley diameter is doubled, the belt tension and pulley width remaining same. The changes required in key will be____________________?
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A. increase key length

B. none of the above

C. increase key width

D. increase key depth

E. double all the dimensions

76. The C.G. of a plane lamina will not be at its geometrical centre in the case of a __________________?
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A. equilateral triangle

B. circle

C. rectangle

D. square

E. right angled triangle
77. Flow stress corresponds to___________________?
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A. rupture stress

B. breaking point

C. plastic deformation of solids

D. none of the above

E. fluids in motion

78. A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to_________________?
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A. 250

B. 500

C. 25

D. 50

E. 100

79. In the tensile test, the phenomenon of slow extension of the material, i. e. stress increasing with the time at a constant load is called_____________?
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A. breaking

B. plasticity

C. yielding

D. creeping

E. none of the above

80. Coulomb friction is the friction between_____________________?
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A. two dry surfaces

B. solids and liquids

C. bodies having relative motion

D. two lubricated surfaces

E. electrically charged particles

81. The impact strength of a material is an index of its ___________________?
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A. toughness

B. hardness

C. fatigue strength

D. tensile strength

E. capability of being cold worked

82. The internal reaction in bottom 80 cm length will be________________?
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A. same in both cases

B. zero in first case

C. different in both cases

D. data are not sufficient to determine same

E. none of the above

83. The angle which an inclined plane makes with the horizontal when a body placed on it is about to move down is known as angle of __________________?
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A. friction

B. limiting friction

C. kinematic friction

D. static friction

E. repose
84. The energy absorbed in a body, when it is strained within the elastic limits, is known as________________?
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A. proof resilience

B. strain energy

C. modulus of resilience

D. resilience

E. toughness

85. For which material the Poissons ratio is more than unity_________________?
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A. copper

B. cast iron

C. aluminium

D. steel

E. none of the above
86. The value of Poissons ratio for cast iron is_________________?
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A. 0.1 to 0.2

B. 0.25 to 0.33

C. 0.23 to 0.27

D. 0.4 to 0.6

E. 3 to 4

87. A riveted joint in which every rivet of a row is opposite to other rivet of the outer row, is known as______________________?
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A. chain riveted joint

B. none of the above

C. criss-cross riveted joint

D. diamond riveted joint

E. zig-zag riveted joint

88. The force acting along the circumference will cause stress in the walls in a direction normal to the longitudinal axis of cylinder; this stress is called___________________?
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A. yeiled stress

B. none of the above

C. longitudinal stress

D. hoop stress

E. ultimate stress

89. A body moves, from rest with a constant acceleration of 5 m per sec. The distance covered in 5 sec is most nearly_______________?
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A. 62.5 m

B. 38 m

C. 124 m

D. 96 m

E. 240 m

90. A material capable of absorbing large amount of energy before fracture is known as________________?
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A. plasticity

B. ductility

C. resilience

D. shock proof

E. toughness
91. The percentage reduction in area of a cast iron specimen during tensile test would be of the order of_________________?
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A. 1025%

B. 510%

C. 2550%

D. negligible

E. more than 50%

92. A cable with a uniformly distributed load per horizontal metre run will take the following shape_________________?
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A. straight line

B. elliptical

C. hyperbola

D. part of a circle

E. parabola
93. A key is subjected to side pressure as well at shearing forces. These pressures are called_________________?
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A. none of the above

B. resultant stresses

C. crushing stresses

D. fatigue stresses

E. bearing stresses
94. Which of the following is the example of lever of first order__________________?
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A. arm of man

B. all of the above

C. none of the above

D. pair of clinical tongs

E. pair of scissors

95. When it is indicated that a member is elastic, it means that when force is applied, it will________________?
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A. none of the above

B. be safest

C. stretch

D. not stretch

E. not deform

96. The value of shear stress which is induced in the shaft due to the applied couple varies____________________?
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A. from maximum at the center to zero at the circumference

B. from zero at the center to maximum at the circumference

C. from maximum at the center to mini-mum at the cricumference

D. from minimum at the centro to maxi-mum at the circumference

E. none of the above

97. The total strain energy stored in a body is termed as__________________?
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A. resilience

B. modulus of resilience

C. proof resilience

D. toughness

E. impact energy

98. The stress developed in a material at breaking point in extension is called_________________?
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A. ultimate tensile stress

B. breaking stress

C. proof stress

D. fracture stress

E. yield point stress

99. The Youngs modulus of a wire is defined as the stress which will increase the length of wire compared to its original length________________?
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A. same amount

B. half

C. one-fourth

D. double

E. four times

100. For steel, the ultimate strength in shear as compared to in tension is nearly _________________?
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A. one-third

B. same

C. one-fourth

D. half

E. two-third