engineering mechanics Mcqs
51. A projectile is fired at an angle 9 to the vertical. Its horizontal range will be maximum when 9 is_______________?
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A. 0

B. 90.

C. 45

D. 60

E. 30

52. Which of the following is not the unit of pressure ?
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A. kg/cm

B. atmosphere

C. ata

D. newton

E. mm of wcl

53. The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is as per the principle of__________________?
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A. forces

B. resolution of forces

C. dependence of forces

D. independence of forces

E. balance of force

54. The center of percussion of the homogeneous rod of length L suspended at the top will be___________________?
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A. 3L/8

B. 2L/3

C. 3L/4

D. L/2

E. L/3

55. The maximum frictional force which comes into play when a body just begins to slide over another surface is called__________________?
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A. sliding friction

B. kinematic friction

C. limiting friction

D. dynamic friction

E. rolling friction

56. Center of percussion is___________________?
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A. point of suspension

B. the point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis

C. the point of C.G.

D. the point in a body about which it can rotate horizontally and oscillate under the influence of gravity

E. the point of metacentre

57. Effect of a force on a body depends upon ________________?
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A. none of the above

B. direction

C. magnitude

D. all of the above

E. position or line of action

58. If a number of forces act simultaneously on a particle, it is possible _____________________?
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A. to replace them by a single force

B. not a replace them by a single force

C. to replace them by a single force through C.G.

D. to replace them by a couple

E. to replace them by a couple and a force

59. A cable with a uniformly distributed load per horizontal meter run will take the following shape________________?
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A. part of a circle

B. elliptical

C. hyperbola

D. straight line

E. parabola
60. If two equal forces of magnitude P act at an angle 9, their resultant will be________________?
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A. P/2 cos 9/2

B. IP cos 9/2

C. Psin 9/2

D. 2P tan 9/2

E. IP sin 9/2

61. Two non-collinear parallel equal forces acting in opposite direction__________________?
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A. constitute a moment of couple

B. balance each other

C. constitute a couple

D. constitute a resultant couple

E. constitute a moment

62. The units of moment of inertia of mass are ________________?
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A. kg m2

B. m4

C. kg/m2

D. kg/m

E. m2/kg

63. A heavy ladder resting on floor and against a vertical wall may not be in equilibrium, if____________________?
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A. the floor is smooth, the wall is rough

B. the floor is rough, the wall is smooth

C. the floor and wall both are smooth surfaces

D. the floor and wall both are rough surfaces

E. will be in equilibrium under all conditions

64. According to law of triangle of forces __________________ ?
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A. three forces acting at a point will be in equilibrium

B. if three forces acting upon a patticle are represented in magnitude and direction by the sides of a triangle, taken in order, they will be in equilibrium

C. none of the above

D. if three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two

E. three forces acting at a point can be represented by a triangle, each side being proportional to force

65. When trying to turn a key into a lock, following is applied _____________________?
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A. moment

B. coplanar force

C. couple

D. non-coplanar forces

E. lever

66. 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

67. The C.G. of a solid hemisphere lies on the central radius 3r________________?
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A. at distance from the plane base or

B. at distance from the plane base 3r

C. at distance from the plane base 3r

D. at distance from the plane base

E. at distance from the plane base 3r

68. Center of gravity of a solid cone lies on the axis at the height _____________________?
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A. one-third of the total height above base

B. one-half of the total height above base

C. none of the above

D. one-fourth of the total height above base

E. three-eighth of the total height above the base

69. 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. none of the above

B. more inclined when moving

C. less inclined when standing

D. more inclined when standing

E. less inclined when moving

70. Dynamic friction as compared to static friction is___________________?
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A. less

B. more

C. may be less of more depending on nature of surfaces and velocity

D. has no correlation

E. same

71. Which of the following is not a vector quantity __________________?
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A. velocity

B. acceleration

C. weight

D. force

E. moment

72. Which is the correct statement about law of polygon of forces ?
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A. if any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon, then the forces are in equilibrium

B. a polygon taken in order, then the forces are in equilibrium

C. if a polygon representing forces acting at a point is closed then forces are in equilibrium

D. if any number of forces acting at a point can be represented by the sides

E. if any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon taken in order, then the forces are in equilibrium

F. none of the above.

73. The forces, which meet at one point, but their lines of action do not lie in a plane, are called_________________?
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A. coplanar non-concurrent forces

B. non-coplanar non-concurrent forces

C. intersecting forces

D. none of the above

E. non-coplanar concurrent forces
74. From a circular plate of diameter 6 cm is cut out a circle whose diameter is a radius of the plate. Find the e.g. of the remainder from the center of circular plate____________________?
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A. 0.25 cm

B. 2.5 cm

C. 1.0 cm

D. 0.5 cm

E. 1.5 cm

75. Angle of friction is the_______________________?
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A. the ratio of minimum friction force to friction force acting when the body is in motion

B. ratio of limiting friction and normal reaction

C. ratio of static and dynamic friction

D. angle between normal reaction and the resultant of normal reaction and the limiting friction

E. the ratio of minimum friction force to the friction force acting when the body is just about to move

76. If a suspended body is struck at the center of percussion, then the pressure on die axis passing through the point of suspension will be_________________?
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A. infinity

B. same as the force applied

C. maximum

D. zero

E. minimum

77. In detennining stresses in frames by methods of sections, the frame is divided into two parts by an imaginary section drawn in such a way as not to cut more than____________________?
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A. three members with known forces of the frame

B. four members with two known forces

C. four members with unknown forces of the frame

D. three members with unknown forces of the frame

E. two members with unknown forces of the frame

78. Which one of the following statements is not correct_________________?
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A. the tangent of the angle of repose is equal to coefficient of friction

B. the angle of repose is equal to angle of friction

C. none of the above

D. the sine of the angle of repose is equal to coefficient to friction

E. the tangent of the angle of friction is equal to coefficient of friction

79. A framed structure is perfect if it contains members equal to_________________?
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A. n 2

B. 2n-3

C. re n = number of joints in a frame

D. 3n-2.

E. n-l

F. 2n-l

80. Frictional force encountered after commencement of motion is called ___________________?
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A. frictional resistance

B. limiting friction

C. kinematic friction

D. dynamic friction

E. post friction

81. Least force required to draw a body up the inclined plane is W sin (plane inclination + friction angle) applied in the direction___________________?
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A. unpredictable

B. along the plane

C. horizontally

D. vertically

E. at an angle equal to the angle of friction to the inclined plane
82. A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span___________________?
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A. 2.0 cm

B. 5.0 cm

C. 2.5 cm

D. 3.0 cm

E. 4.0 cm
83. In the equation of virtual work, following force is neglected_______________________?
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A. reaction of any smooth surface with which the body is in contact

B. reaction of a rough surface of a body which rolls on it without slipping

C. reaction at a point or an axis, fixed in space, around which a body is con-strained to turn

D. all of the above

E. none of the above

84. Pick up the incorrect statement from the following ?
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A. The C.G. of a rectangle is at the inter-section of its diagonals

B. The C.G. of a triangle is at the intersection of its medians

C. The C.G. of a circle is at its center

D. The C.G. of a semicircle is at a distance of r/2 from the center

E. The C-G. of an ellipse is at its center

85. The resultant of the following three couples 20 kg force, 0.5 m arm, $ ve sense 30 kg force, 1 m arm, ve sense 40 kg force, 0.25 m arm, + ve sense having arm of 0.5 m will be__________________?
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A. 10 kg, + ve sense

B. 45 kg, + ve sense

C. 20 kg, ve sense

D. 10 kg, ve sense

E. 20 kg, + ve sense

86. Two coplanar couples having equal and opposite moments_________________?
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A. can not balance each other

B. are equivalent

C. produce a couple and an unbalanced force

D. produce a moment of couple

E. balance each other

87. The center of gravity of a triangle lies at the point of __________________?
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A. intersection of its altitudes

B. intersection of diagonals

C. all of the above

D. concurrence of the medians

E. intersection of bisector of angles

88. The possible loading in various members of framed structures are_________________?
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A. shear or tension

B. all of the above

C. compression or tension

D. bending

E. buckling or shear

89. The ratio of limiting friction and normal reaction is known as _____________________?
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A. angle of friction

B. friction resistance

C. sliding friction

D. coefficient of friction

E. angle of repose

90. The coefficient of friction depends on________________?
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A. shape of surfaces

B. nature of surface

C. strength of surfaces

D. all of the above

E. area of contact

91. On a ladder resting on smooth ground and leaning against vertical wall, the force of friction will be___________________?
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A. downwards at its upper end

B. towards the wall at its upper end

C. none of the above

D. away from the wall at its upper end

E. upwards at its upper end