MULTIPLE-CHOICE QUESTIONS
I. Choose the appropriate/correct choice/choices for the following questions.
1. A particle has
(a) only mass and no size
(b) no mass but only size
(c) neither mass nor size
(d) none of the above are correct concept of a particle.
Ans-a
3. The law ‘the state of rest or motion of the rigid body is unaltered if a force acting on the body is
replaced by another force of the same magnitude and direction but acting anywhere on the body
along the line of action of the replaced force’ is known as
(a) Newton’s 4th law
(b) Law of transmissibility
(c) Lami’s theorem
(d) D’ Alemberts’ principle
Ans-b
4. Which one of the following is fundamental law of forces?
(a) Triangle law
(b) Polygonal law
(c) Parallelogram law
(d) Lami’s theorem
Ans-c
5. Which one of the following is not a vector?
(a) Distance
(b) Velocity
(c) Acceleration
(d) Momentum
Ans-a
6. Unit of constant of gravitation is
(a) m/sec
2
(b) m-sec
(c) N m2
/kg
2
(d) newton
Ans-c
7. 1 newton is the force required to produce an acceleration of
(a) 9.81 m/sec
2
in a body of mass 1 kg
(b) 1 m/sec
2
in a body of mass 1 kg
(c) 9.81 m/sec
2
in a body of mass 1 kg
(d) none of the above
Ans- c
8. If A = 50 N and B = 120 N and A is at 90° to B, the resultant of AB is
(a) 70 N
(b) 130 N
(c) 190 N
(d) none of the above
Ans-b
9. If a 100 N body rests on a plane inclined at 30° to horizontal the component normal to the plane is
(a) 50 N
(b) 86.6 N
(c) 57.7 N
(d) 75 N
Ans-b
10. The angles between the two forces to make their resultant a minimum and a maximum are
respectively
(a) 180° and 0°
(b) 90° and 0°
(c) 180° and 90°
(d) 0° and 180°
Ans-a
11. If two forces P and P/2 are acting on a body at right angles to each other the motion of the body
will be directed at angle ______ to the direction of the force P.
(a) zero
(b) 30°
(c) 45°
(d) none of above
Ans-b
12. Free-body diagram means
(a) the diagram drawn with free hand
(b) the diagram of a body with applied forces
(c) the diagram of a body with applied forces, self-weight and reactions.
(d) the diagram of a freely suspended body.
(d)
Ans-c
14. A string is tied to a spindle passing through a smooth ball of weight w and tied to a smooth wall.
If the string makes angle q with the wall, reaction of the wall is
(a) W sin q
(b) W cos q
(c) W tan q
(d) W cot q
Ans-c
15. If a roller is to be pulled over a curb with least force q required is
(a) vertical
(b) horizontal
(c) 45° to reaction
(d) 90° to the reaction
Ans-d
16. The law stating that the algebraic sum of moments of a system of coplanar forces about a moment
centre is equal to the moment of their resultant force about the same moment centre is known as
(a) Law of transmissibility of forces
(b) Varignon’s theorem
(c) Lami’s theorem
(d) D’Alembert’s principle
Ans-b
17. Which one of the following is the wrong statement about a couple formed by two equal and
opposite parallel forces P separated by d. The effect of a couple is unchanged if
(a) the couple is rotated through any angle
(b) the couple is shifted to any position
(c) the couple is replaced by forces P/2 magnitude with a separation d/2
(d) the couple is replaced by forces of magnitude 2P with a separation of d/2.
(d) none of the above
Ans-c
19. Which one of the following equations is odd in the following group?
(a) SFx = SFy = SFZ = 0
(b) SFx = SFy = SMA = 0
(c) SFy = SMA = SMB = 0, if AB is not in y-direction
(d) SMA = SMB = SMC = 0, if A, B, C are not collinear.
Ans- A
20. In a beam of 6 m span with one end hinged and other on roller if 30 kN-m moment is acting at 2 m
from support A, then the reaction at A is
(a) 15 kN
(b) 7.5 kN
(c) 5 kN
(d) 4 kN
Ans-c
21. Which one of the following is indeterminate beam?
(a) Simply supported beam
(b) Cantilever
(c) One end hinged, other on roller
(d) Both ends hinged
Ans-d
22. The necessary and sufficient condition for a truss with m number of members and j number of
joints to be perfect is
(a) m = 2j – 3
(b) m = 2j + 3
(c) j = 2m – 3
Ans-d
(d) just sufficient members to retain its shape when the load is applied at any joint in any direction
23. Which one of the following is wrong in the list of assumptions for the analysis of pin jointed
tress?
(a) Load acts at joint only
(b) Self-weight neglected
(c) Loads act vertically
(d) Ends of members are pin connected
Ans- c
24. In the method of sections for the analysis of trusses, the section line should
(a) cut at least 3 members
(b) cut only three members
(c) cut 3 members and separate it into two independent parts
(d) cut not more than 3 members and separate the truss into two independent parts.
Ans- D
28. The coefficient of friction depends upon
(a) the area of contact
(b) the roughness of the surface
(c) the shape of contact area
(d) all of the above
Ans-b
29. If F is the limiting friction, N is the normal reaction and R is the resultant of F and N, the angle of
limiting friction is the
(a) angle between F and N
(b) angle between F and R
(c) angle between N and R
(d) none of the above
Ans- c
30. If f is the angle of repose, then the coefficient of friction m is
(a) tan f
(b) cot f
(c) cos f
(d) sec f
Ans-a
31. The angle of inclined plane with the horizontal when a body placed on it is on the verge of sliding
down is known as
(a) angle of friction
(b) cone of friction
(c) coefficient of friction
(d) angle of repose
Ans-a
32. The maximum angle upto which grains can be heaped is known as
(a) angle of friction
(b) cone of friction
(c) coefficient of friction
(d) angle of repose
Ans-d
33. A block weighing W is resting on a plane inclined at q to the horizontal. The coefficient of friction
is m. The force P required to pull it up the plane is
(a) W sin q – m W cos q
(b) W sin q + m W cos q
(c) W cos q – m W sin q
(d) W cos q + m W sin q
Ans-b
34. Compared to static friction, dynamic friction is
(a) more
(b) same
(c) less
(d) depending upon the value of coefficient of friction it may be more or less.
Ans-c
35. Friction is a kind of
(a) active force
(b) reactive force
(c) body force
(d) none of the above
Ans- -b
36. If T1
is the force on slack side and T2 on tight side of a rape passing over a pulley,
(a) T1 = T2 emq
(b) T2 = T1 emq
(c) T1 = mT2
(d) T2 = mT1
Ans- A
40. For the ideal machine,
(a) VR > MA
(b) VR < MA
(c) VR = MA
(d) none of the above
Ans- c
41. If P – actual effort required
Pi – ideal effort required
W – actual load to be lifted.
Wi – ideal load to be lifted
then the efficiency is
(a)
(b)
(c) both (a) and (b)
(d) none of the above
42. The law of machine in terms of load (N), effort (P), constants C and m is
(a) W = mP + C
(b) P = mW + C
(c) C = mP + W
(d) C = mW + P
Ans- b
43. The efficiency of a self-locking machine is
(a) 100%
(b) more than 50%
(c) less than 50%
(d) none of the above
Ans-c
44. If p is the pitch, d is mean diameter of a screw jack, and P is the effort required for lifting load W,
then P is directly proportional to
(a) W tan (q – f)
(b) W tan (q + f)
(c)
(d)
Ans-b
where f is angle of friction.
47. Second moment of area of a figure about x – x axis
(a) Sx
2dA
(b) Sy
2dA
(c) Sr
2dA
(d) SxydA
Ans-b
54. The unit of mass moment of inertia is
(a) N-m-sec
2
(b) N-m/sec
2
(c) N-m2
/sec
(d) none of the above
Ans-b
59. A point on the wheel of a moving vehicle is having
(a) rectilinear translation
(b) curvilinear motion
(c) rotation
(d) general plane motion
Ans-d
60. A body is said to have plane motion when
(a) it moves in a straight line on a plane surface
(b) it moves in a curved path on a plane surface
(c) it rotates around a point
(d) it possesses translation as well as rotation
Ans-d
61. In a velocity time curve the slope represents
(a) velocity
(b) acceleration
(c) displacement
(d) none of the above
Ans-b
62. In a velocity-time curve area under the curve represents
(a) displacement
(b) velocity
(c) acceleration
(d) none of the above
Ans-a
63. In a acceleration-time curve, the velocity is represented by
(a) slope of the curve
(b) ordinate of the curve
(c) area under the curve
(d) none of the above
Ans-c
64. In a displacement-time curve the slope represents
(a) displacement
(b) velocity
(c) acceleration
(d) none of the above
Ans-b
69. An automobile starts from rest form a station P and accelerated uniformly to attain a speed of 48
kmph in 30 seconds. Hence, it covers distance ______ to attain this speed.
(a) 200 m
(b) 300 m
(c) 400 m
(d) 450 m
Ans-a
70. The motion of a particle moving in a straight line is given by
s = t
3 – 3t
2 + 2t + 5.
After 4 seconds, the velocity and accelerations are
(a) 48 m/sec and 40 m/sec
2
(b) 36 m/sec and 24 m/sec
2
(c) 26 m/sec and 18 m/sec
2
(d) none of the above
Ans-c
71. The motion of a particle making in a straight line is given by
Then the extreme velocity is
(a) 2 m/sec
(b) 1 m/sec
(c) –1 m/sec
(d) –2 m/sec
Ans-c
72. A pilot flying his bomber at a height of 1962 m with a uniform velocity of 720 kmph wants to
strike a target. He should release the bomb ______ distance before reaching that target
(a) 4000 m
(b) 3000 m
(c) 2000 m
(d) none of the above
Ans-a
73. If a projectile is fired at angle a with initial velocity u, it traces the
(a) circular path
(b) parabolic path
(c) catenary path
(d) elliptic path
Ans-b
74. A projectile is fired with initial velocity u at an angle 55° to horizontal. Then second projectile
was fired with the same velocity but at an angle 35° to horizontal. Then the ratio of horizontal
projection of first one to second one is
(a) more than 1
(b) equal to 1
(c) less than 1
(d) May be anything depending upon the value of u
Ans-b
75. If air resistance is to be considered, to get maximum range the angle of projection should be
(a) equal to 45°
(b) slightly more than 45°
(c) slightly less than 45° (a) 60°
Ans-b
77. A river is flowing at a velocity of 5 kmph. A motor boat can move at a velocity of 10 kmph with
uniform velocity. To reach the other bank in minimum time the boat should be set at q = … to the
direction of flow
(a) 150°
b) 120°
(c) 90°
(d) 60°
Ans-b
78. The system of forces acting on a moving body is in a dynamic equilibrium with the inertia force of
the body. This low is known as
(a) D’ Alembert’s principle
(b) work-energy principle
(c) impulse momentum theorem
(d) Lami’s theorem
Ans-a
80. A block weighing 300 N is attached to one end and a block weighing 450 N is attached to another
end of a wire. The system is allowed to move over a smooth pulley. Then the ratio of tension in the
wire on 300 N load side to that on 450 N side is
(a) more than 1
(b) less than 1
(c) equal to 1
(d) may be anything depending upon diameter of pulley
Ans-c
81. One Joule of work is equal to
(a) 1 N-mm work
(b) 1 N-m work
(c) 1 kN-m work
(d) none of the above
Ans-b
82. One watt of power is equal to
(a) one joule of work done per second
(b) one kilo-joule of work done per second
(c) one kilo-joule of work done per minute
(d) one joule of work done per minute
Ans-a
89. In a system, if the resultant force is zero, initial momentum remains equal to the final momentum.
This law is known as
(a) impulse momentum equation
(b) conversation of momentum
(c) work energy equation
(d) equilibrium equation
Ans-b
94. A golf ball is dropped from a height of 10 m on a fixed steel plate. The coefficient of restitution is
0.8. The height to which the ball rebounds after the first bounce is
(a) 8.97 m
(b) 11.21 m
(c) 17.94 m
(d) 22.42 m
Ans-a
95. If a ball is dropped on a smooth ground from a height h and coefficient of restitution is e, after the
second bounce the ball rises to a height of
(a) eh
(b) e
2h
(c) 2eh
(d) e
4h
Ans-d
96. If W is the weight of the body, v is velocity, S is the distance moved and R is resultant force, work
energy equation may be stated as
(a) Kinetic energy =
(b) Work done = RS
(c) Work done = Change in kinetic energy
(d) kinetic energy can be changed to other form
Ans-c
97. Unit of momentum is
(a) joule
(b) watt
(c) N-m/sec
(d) n-sec
Ans- d
98. When a body moves in a curved path, centrifugal force to be applied to bring it to dynamic
equilibrium is in the direction
(a) radially inward
(b) radially outward
(c) tangentially forward
(d) tangentially backward
Ans-b
99. When a body of mass m moves in a curved path of radius r with velocity v, centrifugal force
developed is
(a) radially inward
(b) radially outward
(c) radially inward
(d) radially outward
Ans-b
101. On curved path banking is provided to
(a) avoid skidding and overturning
(b) permit higher speed
(c) reduce lateral pressure on wheels
(d) all the above
Ans-d
102. Design speed on a banked curved path is
(a) to avoid skidding of the vehicle
(b) to avoid overturning of the vehicle
(c) to avoid lateral pressure on tyres
(d) all the above
Ans-D
103. If a body rotates with uniform angular acceleration a, starting from initial velocity wo
, the
velocity w after t seconds and angular distance q, which one of the following is not correct
relation?
(a) w = wo + at
(b) w
2 – w
2
o = 2aq
(c) q =
(d) a =
Ans-d
104. The rotation of a flywheel is governed by the equation w = 3t
2 – 2t + 2 where w is in radians per
second and t is in second. After 1 second from the start the angular displacement was 4 radians.
Then the equation for angular displacement q is
(a) t
3 – t
2 + 2t + 2
(b) t
3 – t
2 + 2t
(c) 6t – 2
(d) none of the above
Ans-a
105. If I is mass moment of inertia, a is angular acceleration, w is angular velocity, q is angular
distance, angular momentum is
(a) Iw
(b) Ia
(c)
(d)
106. A motion in which acceleration of the body is directly proportional to its displacement and
directed towards the origin is called
(a) angular motion
(b) curvilinear motion
(c) circular motion
(d) simple harmonic motion
Ans-d
107. At the instantaneous centre, the velocity of the moving lamina at any instant is
(a) zero
(b) maximum
(c) minimum
(d) varying
Ans- A
108. Instantaneous centre for a wheel rolling on straight road is at
(a) point where it touches ground
(b) at top of the weel
(c) in the forward extreme point
(d) in the backward extreme point
Ans-A
109. Instantaneous centre is at infinity when the angular velocity is
(a) maximum
(b) constant
(c) zero
(d) minimum
Ans-c
110. A 3 m long ladder rests against a wall and makes an angle of 60° with the horizontal. When
ladder starts slipping, the instantaneous centre is at
(a) 2.6 m from the floor and 1.5 m from wall
(b) 2.6 m from the wall and 1.5 from floor
(c) 1.73 m from the wall and 1.5 m from floor
(d) 1.73 m from the floor and 1.5 m from wall
Ans-A
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