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On: July 17, 2023 Posted in Internet Comments: 0 Views: 96

Engineering Mechanics Solved MCQs

1.	If three forces acting at a point be represented in magnitude and direction by the three sides of a triangle, taken in order, the forces shall be in equilibrium.
A.	TRUE
B.	False
Answer» A. TRUE

2.	In order to double the period of simple pendulum, the length of the string should be
A.	halved
B.	doubled
C.	quadrupled
Answer» C. quadrupled

3.	The unit of angular acceleration is
A.	N – m
B.	m / s
C.	m / s2
D.	rad / s2
Answer» D. rad / s2

4.	The loss of kinetic energy due to direct impact of two bodies
A.	depends
B.	does not depend
Answer» A. depends

5.	If a given force (or a given system of forces) acting on a body
A.	change
B.	does not change
Answer» B. does not change

6.	For any system of coplaner forces, the condition of equilibrium is that the
A.	algebraic sum of the horizontal components of all the forces should be zero
B.	algebraic sum of the vertical components of all the forces should be zero
C.	algebraic sum of moments of all the forces about any point should be zero
D.	all of the above
Answer» D. all of the above

7.	In a single threaded worm and worm wheel, the number of teeth on the worm is 50. The diameter of the effort wheel is 100 mm and that of load drum is 50 mm. The velocity ratio is
A.	50
B.	100
C.	150
D.	200
Answer» B. 100

8.	In actual machines, mechanical advantage is
A.	equal to
B.	less than
C.	greater than
Answer» B. less than

9.	The angle of inclination of the plane at which the body begins to move down the plane, is called
A.	angle of friction
B.	angle of repose
C.	angle of projection
D.	none of these
Answer» A. angle of friction

10.	The minimum force required to slide a body of weight W on a rough horizontal plane is
A.	W sin ?
B.	W cos ?
C.	W tan ?
D.	none of these
Answer» C. W tan ?

11.	The range of projectile on a downward inclined plane is
A.	less than
B.	more than
C.	equal to
Answer» B. more than

12.	The forces, whose lines of action are parallel to each other and act in the same directions, are known as
A.	coplaner concurrent forces
B.	coplaner non-concurrent forces
C.	like parallel forces
D.	unlike parallel forces
Answer» C. like parallel forces

13.	The distance, between the point of projection and the point where the projectile strikes the ground, is known as range.
A.	Correct
B.	Incorrect
Answer» A. Correct

14.	If tension in the cable supporting a lift moving downwards is half the tension when it is moving upwards, the acceleration of the lift is
A.	g / 2
B.	g / 3
C.	g / 4
D.	none of these
Answer» D. none of these

15.	The impact between two lead spheres is approximately equal to an
A.	elastic
B.	inelastic
Answer» B. inelastic

16.	The angle of the inclined plane at which a body just begins to slide down the plane, is called helix angle.
A.	True
B.	False
Answer» B. False

17.	The total energy possessed by a system of moving bodies
A.	is constant at every instant
B.	varies from point to point
C.	is maximum in the start and minimum at the end
D.	is minimum in the start and maximum at the end
Answer» A. is constant at every instant

18.	Moment of inertia of a circular section about an axis perpendicular to the section is
A.	?d3 / 16
B.	?d3 / 32
C.	?d4 / 32
D.	?d4 / 64
Answer» C. ?d4 / 32

19.	A couple produces
A.	translatory motion
B.	rotational motion
C.	combined translatory and rotational motion
D.	none of the above
Answer» B. rotational motion

20.	A non-reversible machine is also called a self-locking machine
A.	Agree
B.	Disagree
Answer» A. Agree

21.	A body will begin to move down an inclined plane if the angle of inclination of the plane is
A.	equal to
B.	less than
C.	greater than
Answer» C. greater than

22.	Which of the following statement is wrong?
A.	A force acting in the opposite direction to the motion of the body is called force of friction.
B.	The ratio of the limiting friction to the normal reaction is called coefficient of friction.
C.	A machine whose efficiency is 100% is known as an ideal machine.
D.	The velocity ratio of a machine is the ratio of load lifted to the effort applied.
Answer» D. The velocity ratio of a machine is the ratio of load lifted to the effort applied.

23.	When a rigid body is suspended vertically, and it oscillates with a small amplitude under the action of the force of gravity, the body is known as
A.	simple pendulum
B.	compound pendulum
C.	torsional pendulum
D.	second’s pendulum
Answer» B. compound pendulum

24.	A smooth cylinder lying on its convex surface remains in
A.	stable
B.	unstable
C.	neutral
Answer» B. unstable

25.	A machine having an efficiency less than 50%, is known as
A.	reversible machine
B.	non-reversible machine
C.	neither reversible nor non-reversible machine
D.	ideal machine
Answer» B. non-reversible machine

26.	A framed structure is perfect, if the number of members are
A.	equal to
B.	less than
C.	greater than
D.	either (b) or (c)
Answer» A. equal to

27.	A ladder is resting on a rough ground and leaning against a smooth vertical wall. The force of friction will act
A.	downward at its upper end
B.	upward at its upper end
C.	zero at its upper end
D.	perpendicular to the wall at its upper end
Answer» C. zero at its upper end

28.	All the steel trusses of the bridges, have one of their end roller supported, and other end hinged. The main advantage of such a support is that the truss remains stable.
A.	True
B.	False
Answer» A. True

29.	The force required to move the body up the plane will be minimum if it makes an angle with the inclined plane
A.	equal to
B.	less than
C.	greater than
Answer» A. equal to

30.	One watt is equal to
A.	0.1 joule / s
B.	1 joule / s
C.	10 joules / s
D.	100 joules / s
Answer» B. 1 joule / s

31.	Vectors method for the resultant force is also called polygon law of forces.
A.	Correct
B.	Incorrect
Answer» A. Correct

32.	The acceleration of a particle moving with simple harmonic motion, at any instant is given by
A.	?.y
B.	?2.y
C.	?2/y
D.	?3.y
Answer» B. ?2.y

33.	The power developed by a body acted upon by a torque T newton metre (N – m) and revolving at ? radian / s is given by
A.	T.? (in watts)
B.	T.? / 60 (in watts)
C.	T.? / 75 (in kilowatts)
D.	T.? / 4500 (in kilowatts)
Answer» A. T.? (in watts)

34.	The centre of gravity of a hemisphere lies at a distance of 3r / 8 from its base measured along the vertical radius.
A.	Right
B.	Wrong
Answer» A. Right

35.	The friction experienced by a body, when at rest, is known as
A.	static friction
B.	dynamic friction
C.	limiting friction
D.	coefficient of friction
Answer» A. static friction

36.	The centre of percussion is below the centre of gravity of the body and is at a distance equal to
A.	h / kG
B.	h2 / kG
C.	k2G / h
D.	h x kG
Answer» C. k2G / h

37.	A smooth cylinder lying on a
A.	curved surface
B.	convex surface
C.	horizontal surface
Answer» C. horizontal surface

38.	The unit of moment of inertia of an area is
A.	kg-m2
B.	kg-m-s2
C.	kg/m2
D.	m4
Answer» D. m4

39.	A machine which is capable of doing work in the reversed direction, after the effort is re-moved, is called a non-reversible machine.
A.	Yes
B.	No
Answer» B. No

40.	The force applied on a body of mass 100 kg to produce an acceleration of 5 m/s2, is
A.	20N
B.	100N
C.	500N
D.	none of these
Answer» C. 500N

41.	A machine which is capable of doing any work in the reversed direction, after the effort is removed, is called a reversible machine.
A.	True
B.	False
Answer» B. False

42.	The velocity ratio of a simple wheel and axle with D and d as the diameters of effort wheel and load axle, is
A.	D + d
B.	D – d
C.	D x d
D.	D / d
Answer» D. D / d

43.	The centre of oscillation and centre of suspension for a compound pendulum are interchangeable.
A.	True
B.	False
Answer» A. True

44.	The term ‘force’ may be defined as an agent which produces or tends to produce, destroys or tends to destroy motion
A.	Agree
B.	Disagree
Answer» A. Agree

45.	The acceleration of a particle moving with simple harmonic motion is proportional to the displacement of the particle from the mean position.
A.	True
B.	False
Answer» A. True

46.	When a particle moves along a circular path, its acceleration has two components, one is normal component and the other is tangential component of acceleration
A.	True
B.	False
Answer» A. True

47.	If the resultant of two equal forces has the same magnitude as either of the forces, then angle between the two forces is
A.	30?
B.	60?
C.	90?
D.	120?
Answer» D. 120?

48.	The motion of a particle round a fixed axis is
A.	translatory
B.	rotary
C.	circular
D.	translatory as well as rotatry
Answer» C. circular

49.	According to Newton’s first law of motion,
A.	every body continues in its state of rest or of uniform motion, in a straight line, unless it is acted upon by some external force
B.	the rate of change of momentum is directly proportional to the impressed force, and takes place in the same direction, in which the force acts
C.	to every action, there is always an equal and opposite reaction
D.	none of the above
Answer» A. every body continues in its state of rest or of uniform motion, in a straight line, unless it is acted upon by some external force

50.	Two equal and opposite parallel forces whose lines of action are different, can be replaced by a single force parallel to the given forces
A.	Correct
B.	Incorrect
Answer» B. Incorrect

51.	Non-coplaner non-concurrent forces are those forces which
A.	meet at one point, but their lines of action do not lie on the same plane
B.	do not meet at one point and their lines of action do not lie on the same plane
C.	do not meet at one point, but their lines of action lie on the same plane
D.	none of the above
Answer» B. do not meet at one point and their lines of action do not lie on the same plane

52.	A machine having an efficiency greater than 50%, is known as
A.	reversible machine
B.	non-reversible machine
C.	neither reversible nor non-reversible machine
D.	ideal machine
Answer» A. reversible machine

53.	The time taken by a particle for one complete oscillation is known as periodic time.
A.	Agree
B.	Disagree
Answer» A. Agree

54.	The centre of gravity of a right circular solid cone is at a distance of
A.	h / 2
B.	h / 3
C.	h / 4
D.	h / 6
Answer» C. h / 4

55.	In order to determine the effects of a force, acting on a body, we must know
A.	magnitude of the force
B.	line of action of the force
C.	nature of the force i.e. whether the force is push or pull
D.	all of the above
Answer» D. all of the above

56.	The ratio of static friction to dynamic friction is always
A.	equal to one
B.	less than one
C.	greater than one
D.	none of these
Answer» C. greater than one

57.	Two equal and opposite parallel forces whose lines of action are different form a couple.
A.	Right
B.	Wrong
Answer» A. Right

58.	The range of a projectile is maximum, when the angle of projection is
A.	30?
B.	45?
C.	60?
D.	90?
Answer» B. 45?

59.	The mechanical advantage of a lifting machine is the ratio of
A.	distance moved by effort to the distance moved by load
B.	load lifted to the effort applied
C.	output to the input
D.	all of the above
Answer» B. load lifted to the effort applied

60.	Moment of inertia of a circular section about its diameter (d) is
A.	?d3 / 16
B.	?d3 / 32
C.	?d4 / 32
D.	?d4 / 64
Answer» D. ?d4 / 64

61.	The total motion possessed by a body, is called
A.	impulsive force
B.	mass
C.	weight
D.	momentum
Answer» D. momentum

62.	Which of the following are vector quantities?
A.	Linear displacement
B.	Linear velocity
C.	Linear acceleration
D.	all of these
Answer» D. all of these

63.	The radius of gyration is the distance where the whole mass (or area) of a body is assumed to be concentrated.
A.	Correct
B.	Incorrect
Answer» A. Correct

64.	A weight of 1000 N can be lifted by an effort of 80 N. If the velocity ratio is 20, the machine is
A.	reversible
B.	non-reversible
C.	ideal
Answer» A. reversible

65.	A lifting machine lifts a load of 1000N through a distance of 0.2 m by means of an effort of 200N through a distance of 1m. This machine is an ideal one.
A.	Right
B.	Wrong
Answer» A. Right

66.	The velocity ratio of a single purchase crab winch can be increased by
A.	increasing the length of the handle
B.	increasing the radius of the load drum
C.	increasing the number of teeth of the pinion
D.	all of the above
Answer» A. increasing the length of the handle

67.	When two elastic bodies collide with each other,
A.	the two bodies will momentarily come to rest after collision
B.	the two bodies tend to compress and deform at the surface of contact
C.	the two bodies begin to regain their original shape
D.	all of the above
Answer» D. all of the above

68.	Moment of inertia is the
A.	second moment of force
B.	second moment of area
C.	second moment of mass
D.	all of these
Answer» D. all of these

69.	The force which acts along the radius of a circle and directed away from the centre of the circle is called centrifugal force
A.	Agree
B.	Disagree
Answer» A. Agree

70.	When a person, on a bicycle, drives round a curve, he has to lean
A.	inward
B.	outward
Answer» A. inward

71.	The bodies which rebound after impact are called
A.	inelastic bodies
B.	elastic bodies
C.	neither elastic nor inelastic bodies
D.	none of these
Answer» B. elastic bodies

72.	If the number of pulleys in a system is equal to its velocity ratio, then it is a
A.	first
B.	second
C.	third
Answer» B. second

73.	The energy possessed by a body, for doing work by virtue of its position, is called
A.	potential energy
B.	kinetic energy
C.	electrical energy
D.	chemical energy
Answer» A. potential energy

74.	The matter contained in a body, is called
A.	impulsive force
B.	mass
C.	weight
D.	momentum
Answer» B. mass

75.	The motion of a wheel of a car is
A.	purely translation
B.	purely rotational
C.	combined translation and rotational
D.	none of these
Answer» C. combined translation and rotational

76.	The resultant of the two forces P and Q is R. If Q is doubled, the new resultant is perpendicular to P. Then
A.	P = Q
B.	Q = R
C.	Q = 2R
D.	none of these
Answer» B. Q = R

77.	Moment of inertia of a triangular section of base (b) and height (h) about an axis through its base, is
A.	bh3 / 4
B.	bh3 / 8
C.	bh3 / 12
D.	bh3 / 36
Answer» C. bh3 / 12

78.	According to lami’s theorem
A.	the three forces must be equal
B.	the three forces must be at 120? to each other
C.	the three forces must be in equilibrium
D.	if the three forces acting at a point are in equilibrium, then each force is proportional to the sine of the angle between the other two
Answer» D. if the three forces acting at a point are in equilibrium, then each force is proportional to the sine of the angle between the other two

79.	The centre of gravity of a rectangle lies at a point where its two diagonals meet each other.
A.	Agree
B.	Disagree
Answer» A. Agree

80.	A pendulum which executes one beat per second is known as
A.	simple pendulum
B.	compound pendulum
C.	torsional pendulum
D.	second’s pendulum
Answer» D. second’s pendulum

81.	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 known as
A.	principle of independence of forces
B.	principle of resolution of forces
C.	principle of transmissibility of forces
D.	none of these
Answer» B. principle of resolution of forces

82.	Which of the fololowing statement is correct in connection with projectiles?
A.	A path, traced by a projectile in the space, is known as trajectory.
B.	The velocity with which a projectile is projected, is known as the velocity of projection.
C.	The angle, with the horizontal, at which a projectile is projected is known as angle of projection.
D.	all of the above
Answer» D. all of the above

83.	The angle of inclination with the vertical is
A.	more
B.	less
Answer» A. more

84.	The centre of gravity of an equilateral triangle with each side a, is
A.	?3 a/2
B.	2?3 a
C.	a/2 ?3
D.	3?2 a
Answer» C. a/2 ?3

85.	In a screw jack, the effort required to lift the load is given by. Where W = Load lifted, ? = Helix angle, and ? = Angle of friction
A.	P = W tan (? ? ?)
B.	P = W tan (? + ?)
C.	P = W tan (? – ?)
D.	P = W tan (? + ?)
Answer» B. P = W tan (? + ?)

86.	Static friction is always
A.	equal to
B.	less than
C.	greater than
Answer» C. greater than

87.	If a number of forces acting at a point be represented in magnidude and direction by the three sides of a triangle, taken in order, then the forces are not in equilibrium
A.	Agree
B.	Disagree
Answer» B. Disagree

88.	One joule means that
A.	work is done by a force of 1 N when it displaces a body through 1 m
B.	work is done by a force of 1 kg when it displaces a body through 1 m
C.	work is done by a force of 1 dyne when it displaces a body through 1 cm
D.	work is done by a force of 1 g when it displaces a body through 1 cm
Answer» A. work is done by a force of 1 N when it displaces a body through 1 m

89.	The velocity ratio for the third system of pulleys is
A.	n
B.	n2
C.	2n
D.	2n – 1
Answer» D. 2n – 1

90.	A rubber ball is dropped from a height of 2 m. If there is no loss of velocity after rebounding, the ball will rise to a height of
A.	1 m
B.	2 m
C.	3 m
D.	4 m
Answer» B. 2 m

91.	Three forces acting on a rigid body are represented in magnitude, direction and line of action by the three sides of a triangle taken in order. The forces are equivalent to a couple whose moment is equal to
A.	area of the triangle
B.	twice the area of the triangle
C.	half the area of the triangle
D.	none of these
Answer» B. twice the area of the triangle

92.	Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its C.G. and parallel to the base, is
A.	bh3 / 4
B.	bh3 / 8
C.	bh3 / 12
D.	bh3 / 36
Answer» D. bh3 / 36

93.	The triangle law of forces states that if two forces acting simultaneously on a particle, be represented in magnitude and direction by the two sides of a triangle taken in order, then their resultant may be represented in mangnitude and direction by the third side of of a triangle, taken in opposite order.
A.	TRUE
B.	FALSE
Answer» A. TRUE

94.	The friction experienced by a body, when in motion, is known as
A.	rolling friction
B.	dynamic friction
C.	limiting friction
D.	static friction
Answer» B. dynamic friction

95.	The forces, which do not meet at one point, but their lines of action lie on the same plane, are known as coplaner concurrent forces
A.	Agree
B.	Disagree
Answer» A. Agree

96.	A redundant frame is also called
A.	perfect
B.	imperfect
C.	deficient
Answer» B. imperfect

97.	The process of finding out the resultant force is called
A.	composition
B.	resolution
Answer» A. composition

98.	A lead ball with a certain velocity is made to strike a wall, it falls down, but rubber ball of same mass and with same velocity strikes the same wall, it rebounds. Select the correct reason from the following
A.	both the balls undergo an equal change in momentum
B.	the change in momentum suffered by rubber ball is more than the lead balf
C.	the change in momentum suffered by rubber ball is less than the lead ball
D.	none of the above
Answer» B. the change in momentum suffered by rubber ball is more than the lead balf

99.	The centre of gravity of a semi-circle lies at a distance of
A.	3r/8
B.	4r/3?
C.	8r / 3
D.	3r / 4?
Answer» B. 4r/3?

100.	The velocity ratio of a first system of pulleys with 4 pulleys is
A.	4
B.	8
C.	16
D.	20
Answer» C. 16

101.	A screw jack used for lifting the loads is
A.	a reversible machine
B.	a non-reversible machine
C.	an ideal machine
D.	none of these
Answer» B. a non-reversible machine

102.	The potential energy stord by a spring in compression, is called strain energy.
A.	Yes
B.	No
Answer» A. Yes

103.	The coefficient of restitution for inelastic bodies is
A.	zero
B.	one
C.	between zero and one
D.	more than one
Answer» A. zero

104.	Coefficient of friction is the ratio of the limiting friction to the normal reaction between the two bodies.
A.	Yes
B.	No
Answer» A. Yes

105.	If a number of forces are acting at a point, their resultant will be inclined at an angle ? with the horizontal, such that
A.	tan ? = ?H / ?V
B.	tan ? = ?V / ?H
C.	tan ? = ?V x ?H
Answer» B. tan ? = ?V / ?H

106.	Energy may be defined as the capacity of doing work.
A.	Correct
B.	Incorrect
Answer» A. Correct

107.	The skidding away of the vehicle on a level circular path can be avoided if the force of friction between the wheels and the ground is
A.	less than
B.	greater than
Answer» B. greater than

108.	The moment of inertia of a solid sphere of mass m and radius r is
A.	2mr2 / 3
B.	2mr2 / 5
C.	mr2
D.	mr2 / 2
Answer» B. 2mr2 / 5

109.	Two like parallel forces are acting at a distance of 24 mm apart and their resultant is 20 N. If the line of action of the resultant is 6 mm from any given force the two forces are
A.	15 N and 5 N
B.	20 N and 5 N
C.	15 N and 10 N
D.	none of these
Answer» A. 15 N and 5 N

110.	The range of projectile will be maximum for a given velocity of projectile, when the angle of projection (?) is
A.	? / 2
B.	30? + ?/2
C.	45? + ?/2
D.	60? + ?/2
Answer» C. 45? + ?/2

111.	Which of the following is a scalar quantity?
A.	Force
B.	Speed
C.	Velocity
D.	Acceleration
Answer» B. Speed

112.	The maximum velocity of a particle moving with simple harmonic motion is
A.	?
B.	?r
C.	?2r
D.	?/r
Answer» B. ?r

113.	A differential pulley block has larger and smaller diameters of 100 mm and 80 mm respectively. Its velocity ratio is
A.	5
B.	10
C.	20
D.	40
Answer» B. 10

114.	The coefficient of restitution for elastic bodies is one
A.	Right
B.	Wrong
Answer» B. Wrong

115.	In ideal machines, mechanical advantage is
A.	equal to
B.	less than
C.	greater than
Answer» A. equal to

116.	If the efficiency of a lifting machine is kept constant, its velocity ratio is
A.	directly
B.	inversely
Answer» A. directly

117.	If the resultant of a number of forces acting on a body is zero, then the body will not be in equilibrium
A.	Yes
B.	No
Answer» B. No

118.	The velocity ratio for the first system of pulleys is. Where n is the number of pulleys.
A.	n
B.	n2
C.	2n
D.	2n – 1
Answer» C. 2n

119.	The angle which the normal reaction makes with the resultant reaction is called angle of friction.
A.	Agree
B.	Disagree
Answer» A. Agree

120.	Which of the following statement is correct?
A.	The kinetic egergy of a body during impact remains constant.
B.	The kinetic energy of a body before impact is equal to the kinetic energy of a body after impact.
C.	The kinetic energy of a body before impact is less than the kinetic energy of a body after impact.
D.	The kinetic energy of a body before impact is more than the kinetic energy of a body after impact.
Answer» D. The kinetic energy of a body before impact is more than the kinetic energy of a body after impact.

121.	If a number of coplaner forces acting at a point be in equilibrium, the sum of clockwise moments must be
A.	equal to
B.	less than
C.	greater than
Answer» A. equal to

122.	An irregular body may have more than one centre of gravity.
A.	Yes
B.	No
Answer» A. Yes

123.	The velocity of a particle moving with simple harmonic motion is
A.	zero
B.	minimum
C.	maximum
Answer» C. maximum

124.	The polygon law of forces states that if a number of forces, acting simultaneously on a particle, be represented in magnitude and direction by the sides a polygon taken in order, then their resultant is represented in magnitude and direction by the closing side of the polygon, taken in opposite direction.
A.	Correct
B.	Incorrect
Answer» A. Correct

125.	The efficiency of a lifting machine is the ratio of
A.	output to the input
B.	work done by the machine to the work done on the machine
C.	mechanical advantage to the velocity ratio
D.	all of the above
Answer» D. all of the above

126.	The three forces of 100 N, 200 N and 300 N have their lines of action parallel to each other but act in the opposite directions. These forces are known as
A.	coplaner concurrent forces
B.	coplaner non-concurrent forces
C.	like parallel forces
D.	unlike parallel forces
Answer» D. unlike parallel forces

127.	The moment of inertia of a square of side about its diagonal is
A.	a2 / 8
B.	a3 / 12
C.	a4 / 12
D.	a4 / 16
Answer» C. a4 / 12

128.	Joule is the unit of
A.	force
B.	work
C.	power
D.	energy
Answer» B. work

129.	In railways, the super-elevation is expressed in terms of the difference of level between the two rails.
A.	True
B.	False
Answer» A. True

130.	The moment of a force
A.	is the turning effect produced by a force, on the body, on which it acts
B.	is equal to the product of force acting on the body and the perpendicular distance of a point and the line of action of the force
C.	is equal to twice the area of the triangle, whose base is the line representing the force and whose vertex is the point, about which the moment is taken
D.	all of the above
Answer» D. all of the above

131.	The moment of inertia of a sphere of mass m and radius r, about an axis tangential to it, is
A.	2mr2 / 3
B.	2mr2 / 5
C.	7mr2 / 3
D.	7mr2 / 5
Answer» D. 7mr2 / 5

132.	If three coplaner forces acting on a point are in equilibrium, then each force is proportional to the sine of the angle between the other two
A.	Right
B.	Wrong
Answer» A. Right

133.	The centre of gravity a T-section 100 mm x 150 mm x 50 mm from its bottom is
A.	50 mm
B.	75 mm
C.	87.5 mm
D.	125 mm
Answer» C. 87.5 mm

134.	The rate of change of momentum is directly proportional to the impressed force, and takes place in the same direction in which the force acts. This statement is known as
A.	Newton’s first law of motion
B.	Newton’s second law of motion
C.	Newton’s third law of motion
D.	none of these
Answer» B. Newton’s second law of motion

135.	The point, through which the whole weight of the body acts, irrespective of its position, is known as
A.	moment of inertia
B.	centre of gravity
C.	centre of percussion
D.	centre of mass
Answer» B. centre of gravity

136.	The moment of inertia of a rectangular section 3cm wide and 4cm deep about X-X axis is
A.	9 cm4
B.	12 cm4
C.	16 cm4
D.	20 cm4
Answer» C. 16 cm4

137.	The angle of inclination of a vehicle when moving along a circular path
A.	depends
B.	does not depend
Answer» B. does not depend

138.	A science teacher claimed that Newton’s third law of motion is involved while studying the motion of rockets. His statement is
A.	justified
B.	not justified
Answer» A. justified

139.	The forces, which meet at one point and their lines of action also lie on the same plane, are known as
A.	coplaner concurrent forces
B.	coplaner non-concurrent forces
C.	non-coplaner concurrent forces
D.	non-coplaner non-concurrent forces
Answer» A. coplaner concurrent forces

140.	The law of motion involved in the recoil of gun is
A.	Newton’s first law of motion
B.	Newton’s second law of motion
C.	Newton’s third law of motion
D.	none of these
Answer» C. Newton’s third law of motion

141.	The force, by which the body is attracted, towards the centre of the earth, is called
A.	impulsive force
B.	mass
C.	weight
D.	momentum
Answer» C. weight

142.	The moment of inertia of a thin spherical shell of mass m and radius r, about its diameter is
A.	mr2 / 3
B.	2mr2 / 3
C.	2mr2 / 5
D.	3mr2 / 5
Answer» B. 2mr2 / 3

143.	The total time taken by a projectile to reach maximum height and to return back to the ground, is known as time of flight.
A.	Yes
B.	No
Answer» A. Yes

144.	If the gravitational acceleration at any place is doubled, then the weight of a body will be
A.	g / 2
B.	g
C.	?2 g
D.	2g
Answer» D. 2g

145.	The term ‘centroid’ is
A.	the same as centre of gravity
B.	the point of suspension
C.	the point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis
D.	none of the above
Answer» A. the same as centre of gravity

146.	If three forces acting at a point are represented in magnitude and direction by the three sides of a triangle, taken in order, then the forces are in equilibrium
A.	Yes
B.	No
Answer» A. Yes

147.	If a pendulum is taken 1 km below the earth surface in a mine, it will
A.	gain
B.	loose
Answer» A. gain

148.	The ideal angle of banking provided on the curves on roads depends upon
A.	weight of the vehicle
B.	(velocity)2 of the vehicle
C.	nature of the road surface
D.	coefficient of friction between the road and vehicle contact point
Answer» B. (velocity)2 of the vehicle

149.	The periodic time of a particle with simple harmonic motion is
A.	directly
B.	inversely
Answer» B. inversely

150.	The acceleration of a body sliding down an inclined surface is
A.	g sin ?
B.	g cos ?
C.	g tan ?
D.	none of these
Answer» A. g sin ?

151.	The centre of gravity of a right angled triangle lies at its geometrical centre.
A.	Correct
B.	Incorrect
Answer» B. Incorrect

152.	The moment of inertia of a solid cone of mass m and base radius r about its vertical axis is
A.	3mr2 / 5
B.	3mr2 / 10
C.	2mr2 / 5
D.	4mr2 / 5
Answer» B. 3mr2 / 10

153.	The amount by which the outer edge of the rail is raised, is known as super-elevation.
A.	Agree
B.	Disagree
Answer» A. Agree

154.	The maximum efficiency of a lifting machine is
A.	1 / m
B.	V.R. / m
C.	m / V.R.
D.	1 / m x V.R.
Answer» D. 1 / m x V.R.

155.	Which of the following statement is correct?
A.	The algebraic sum of the forces, constituting the couple is zero.
B.	The algebraic sum of the forces, constituting the couple, about any point is the same.
C.	A couple cannot be balanced by a single force but can be balanced only by a couple of opposite sense
D.	all of the above
Answer» D. all of the above

156.	If two bodies having masses m1 and m2 (m1 > m2) have equal kinetic energies, the momentum of body having mass m1 is
A.	equal to
B.	less than
C.	greater than
Answer» C. greater than

157.	The rate of doing work is known as
A.	potential energy
B.	kinetic energy
C.	power
D.	none of these
Answer» C. power

158.	Non-coplaner concurrent forces are those forces which
A.	meet at one point, but their lines of action do not lie on the same plane
B.	do not meet at one point and their lines of action do not lie on the same plane
C.	meet at one point and their lines of action also lie on the same plane
D.	do not meet at one point, but their lines of action lie on the same plane
Answer» A. meet at one point, but their lines of action do not lie on the same plane

159.	According to principle of conservation of energy, the total momentum of a system of masses in any direction remains constant unless acted upon by an external force in that direction.
A.	True
B.	False
Answer» B. False

160.	The total momentum of a system of masses (i.e. moving bodies) in any one direction remains constant, unless acted upon by an external force in that direction. This statement is called
A.	Newton’s first law of motion
B.	Newton’s second law of motion
C.	principle of conservation of energy
D.	principle of conservation of momentum
Answer» D. principle of conservation of momentum

161.	The unit of force in S.I. system of units of
A.	dyne
B.	kilogram
C.	newton
D.	watt
Answer» C. newton

162.	Which of the following are vector quantities?
A.	Angular displacement
B.	Angular velocity
C.	Angular acceleration
D.	all of these
Answer» D. all of these

163.	The loss of kinetic energy during elastic impact is zero.
A.	Agree
B.	Disagree
Answer» A. Agree

164.	The centre of gravity of a triangle lies at a point where its medians intersect each other.
A.	True
B.	False
Answer» A. True

165.	D’ Alembert’s principle basically depends upon Newton’s second law of motion.
A.	Correct
B.	Incorrect
Answer» A. Correct

166.	In order to completely specify angular displacement by a vector, it must fix
A.	direction of the axis of rotation
B.	magnitude of angular displacement
C.	sense of angular displacement
D.	all of these
Answer» D. all of these

167.	Two forces are acting at an angle of 120?. The bigger force is 40N and the resultant is perpendicular to the smaller one. The smaller force is
A.	20N
B.	40N
C.	40N
D.	none of these
Answer» A. 20N

168.	When a particle moves along a circular path with uniform velocity, there will be no tangential acceleration.
A.	Correct
B.	Incorrect
Answer» A. Correct

169.	One joule is equal to
A.	0.1 N – m
B.	1 N – m
C.	10 N – m
D.	100 N – m
Answer» B. 1 N – m

170.	Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its vertex and parallel to the base, is
A.	nine times
B.	six times
C.	four times
D.	two times
Answer» A. nine times

171.	The kinetic energy of a body
A.	does not depend
B.	depends
Answer» B. depends

172.	A newton is defined as the force while acting upon a mass of one kg, produces an acceleration of 1 m/s2 in the direction of which it acts.
A.	Yes
B.	No
Answer» A. Yes

173.	The resultant of two forces P and Q (such that P > Q) acting along the same straight line, but in opposite direction, is given by
A.	P + Q
B.	P – Q
C.	P / Q
D.	Q / P
Answer» B. P – Q

174.	A framed structure is imperfect, if the number of members are
A.	equal to
B.	less than
C.	greater than
D.	either (b) or (c)
Answer» D. either (b) or (c)

175.	The resultant of two equal forces P making an angle ?, is given by
A.	2 P sin ?/2
B.	2 P cos ? / 2
C.	2 P tan ?/2
D.	2 P cot ?/2
Answer» B. 2 P cos ? / 2

176.	The unit of mass moment of intertia in S.I. units is kg – m2
A.	True
B.	False
Answer» A. True

177.	When a body falls freely under gravitational force, it possesses
A.	no
B.	minimum
C.	maximum
Answer» A. no

178.	The potential energy of a vertically raised body is
A.	equal to
B.	less than
C.	greater than
Answer» A. equal to

179.	The moment of inertia of a square of side a about its base is a4 / 3
A.	True
B.	False
Answer» A. True

180.	The forces which meet at one point, but their lines of action
A.	lie
B.	do not lie
Answer» B. do not lie

181.	The amplitude is always
A.	equal to
B.	less than
C.	greater than
Answer» A. equal to

182.	The static friction
A.	bears a constant ratio to the normal reaction between the two surfaces
B.	is independent of the area of contact, between the two surfaces
C.	always acts in a direction, opposite to that in which the body tends to move
D.	all of the above
Answer» D. all of the above

183.	A lift moves downwards with an acceleration of 9.8 m/s2. The pressure exerted by a man on the floor of the lift is zero.
A.	True
B.	False
Answer» A. True

184.	One kg force is equal to
A.	7.8 N
B.	8.9 N
C.	9.8 N
D.	12 N
Answer» C. 9.8 N

185.	A force acting in the opposite direction to the motion of the body is called force of friction.
A.	Agree
B.	Disagree
Answer» A. Agree

186.	The moment of inertia of a thin disc of mass m and radius r, about an axis through its centre of gravity and perpendicular to the plane of the disc is
A.	mr2 / 2
B.	mr2 / 4
C.	mr2 / 6
D.	mr2 / 8
Answer» A. mr2 / 2

187.	If the body falls freely under gravity, then the gravitational acceleration is taken as
A.	Plus 8.9 m/s2
B.	? 8.9 m/s2
C.	Plus 9.8 m/s2
D.	? 9.8 m/s2
Answer» C. Plus 9.8 m/s2

188.	Mass moment of inertia of a thin rod about its one end is
A.	same as
B.	twice
C.	thrice
D.	four times
Answer» D. four times

189.	Newton’s second law motion
A.	gives
B.	does not give
Answer» A. gives

190.	The principle of transmissibility of forces states that, when a force acts upon a body, its effect is
A.	same at every point on its line of action
B.	different at different points on its line of action
C.	minimum, if it acts at the centre of gravity of the body
D.	maximum, if it acts at the centre of gravity of the body
Answer» C. minimum, if it acts at the centre of gravity of the body

191.	When a body of mass moment of inertia / (about a given axis) is rotated about that axis with an angular velocity ?, then the kinetic energy of rotation is
A.	I ?
B.	I ?2
C.	0.5 I ?
D.	0.5 I ?2
Answer» D. 0.5 I ?2

192.	The unit of work in S.I. units is
A.	newton
B.	erg
C.	kg-m
D.	joule
Answer» D. joule

193.	In a screw jcak, the effort required to lower the load is
A.	less than
B.	equal to
C.	more than
Answer» A. less than

194.	The terms ‘leverage’ and ‘mechanical advantage’ of a compound lever have got the same meaning.
A.	Right
B.	Wrong
Answer» A. Right

195.	An ideal machine is one whose efficiency is
A.	between 60 to 70%
B.	between 70 to 80%
C.	between 80 to 90%
D.	100%
Answer» D. 100%

196.	Tension in the cable supporting a lift is more when the lift is moving
A.	upwards
B.	downwards
Answer» A. upwards

197.	When the lift is moving upwards with some acceleration, the pressure exerted by a man is
A.	directly
B.	inversely
Answer» A. directly

198.	If a body is thrown upwards, then the gravitational acceleration is taken as zero.
A.	Right
B.	Wrong
Answer» B. Wrong

199.	The length of a second’s pendulum is
A.	94.9 cm
B.	99.4 cm
C.	100 cm
Answer» B. 99.4 cm

200.	Varingon’s theorem of moments states that if a number of coplaner forces acting on a particle are in equilibrium, then
A.	their algebraic sum is zero
B.	their lines of action are at equal distances
C.	the algebraic sum of their moments about any point in their plane is zero
D.	the algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point
Answer» D. the algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point

201.	A ladder is resting on a smooth ground and leaning against a rough vertical wall. The force of friction will act
A.	towards the wall at its upper and
B.	away from the wall at its upper end
C.	downward at its upper end
D.	upward at its upper end
Answer» D. upward at its upper end

202.	The forces which do not meet at one point and their lines of action do not lie on the same plane are known as
A.	coplaner concurrent forces
B.	coplaner non-concurrent forces
C.	non-coplaner concurrent forces
D.	none of these
Answer» D. none of these

203.	The linear acceleration (a) of a body rotating along a circular path of radius (r) with an angular acceleration of ? rad / s2, is
A.	a = ? / r
B.	a = ?.r
C.	a = r / ?
D.	none of these
Answer» B. a = ?.r

204.	The velocity ratio in case of an inclined plane inclined at angle ? to the horizontal and weight being pulled up the inclined plane by vertical effort is
A.	sin ?
B.	cos ?
C.	tan ?
D.	cosec ?
Answer» A. sin ?

205.	A body of mass m moving with a constant velocity v strikes another body of same mass m moving with same velocity but in opposite direction. The common velocity of both the bodies after collision is
A.	v
B.	2 v
C.	4 v
D.	8 v
Answer» B. 2 v

206.	When a body of mass m attains a velocity v from rest in time t, then the kinetic energy of translation is
A.	mv2
B.	mgv2
C.	0.5 mv2
D.	0.5 mgv2
Answer» C. 0.5 mv2

207.	Whenever a force acts on a body and the body undergoes a displacement, then
A.	work is said to be done
B.	power is being transmitted
C.	body has kinetic energy of translation
D.	none of these
Answer» A. work is said to be done

208.	The maximum displacement of a body, from its mean position is called amplitude.
A.	Right
B.	Wrong
Answer» A. Right

209.	The unit of power in S.I. units is
A.	horsepower
B.	joule
C.	watt
D.	kg-m
Answer» C. watt

210.	The moment of inertia of a solid cylinder of mass m, radius r and length l about the longitudenal axis or polar axis is
A.	mr2 / 2
B.	mr2 / 4
C.	mr2 / 6
D.	mr2 / 8
Answer» A. mr2 / 2

211.	When the spring of a watch is wound, it will possess
A.	strain energy
B.	kinetic energy
C.	heat energy
D.	electrical energy
Answer» A. strain energy

212.	The path of the projectile is a parabola.
A.	True
B.	False
Answer» A. True

213.	The wheels of a moving car possess
A.	potential energy only
B.	kinetic energy of translation only
C.	kinetic energy of rotation only
D.	kinetic energy of translation and rotation both
Answer» D. kinetic energy of translation and rotation both

214.	Frequency of vibrations means the number of cycles per second.
A.	Yes
B.	No
Answer» A. Yes

215.	A resultant force is a single force which produces the same effect as produced by all the given forces acting on a body
A.	TRUE
B.	FALSE
Answer» A. TRUE

216.	The maximum mechanical advantage of a lifting machine is
A.	1 + m
B.	1 – m
C.	1 / m
D.	m
Answer» C. 1 / m

217.	In a wormed geared pully block, if the number of teeth one the worm wheel is doubled, then its velocity ratio is also doubled.
A.	True
B.	False
Answer» A. True

218.	The moment of inertia of a thin rod of mass m and length l, about an axis through its centre of gravity and perpendicular to its length is
A.	ml2 / 4
B.	ml2 / 6
C.	ml2 / 8
D.	ml2 / 12
Answer» D. ml2 / 12

219.	Coplaner non-concurrent forces are those forces which
A.	meet
B.	do not meet
Answer» B. do not meet

220.	The linear velocity of a body rotating at ? rad / s along a circular path of radius r is given by
A.	? / r
B.	?.r
C.	?2/r
D.	?2.r
Answer» B. ?.r

221.	The acceleration of a particle moving with simple harmonic motion is
A.	zero
B.	minimum
C.	maximum
Answer» A. zero

222.	When a train is rounding a curve, the side thrust on the wheel flanges is prevented by raising the outer edge of the rail.
A.	Yes
B.	No
Answer» A. Yes

223.	In collision of elastic bodies, the coefficient of restitution is the ratio of the relative velocity after impact to the relative velocity before impact.
A.	True
B.	False
Answer» A. True

224.	The rate of change of displacement of a body is called
A.	velocity
B.	acceleration
C.	momentum
D.	none of these
Answer» A. velocity

225.	The maximum frictional force, which comes into play, when a body just begins to slide over the surface of the other body, is known as
A.	static friction
B.	dynamic friction
C.	limiting friction
D.	coefficient of friction
Answer» C. limiting friction

226.	The negative acceleration is called retardation.
A.	True
B.	False
Answer» A. True

227.	The velocity ratio for the second system of pulleys is n.
A.	True
B.	False
Answer» A. True

228.	The angle between two forces when the resultant is maximum and minimum respectively are
A.	0? and 180?
B.	180? and 0?
C.	90? and 180?
D.	90? and 0?
Answer» A. 0? and 180?

229.	The angular velocity (in rad / s) of a body rotating at N revolutions per minute is
A.	? N / 60
B.	? N / 180
C.	2? N / 60
D.	2? N/180
Answer» C. 2? N / 60

230.	If P is the force acting on the body, m is the mass of the body and a is the acceleration of the body, then according to Newton’s second law of motion,
A.	P + m.a = 0
B.	P – m.a = 0
C.	P x m.a = 0
D.	P/m.a = 0
Answer» B. P – m.a = 0

231.	Coplaner concurrent forces are those forces which
A.	meet at one point, but their lines of action do not lie on the same plane
B.	do not meet at one point and their lines of action do not lie on the same plane
C.	meet at one point and their lines of action also lie on the same plane
D.	do not meet at one point, but their lines of action lie on the same plane
Answer» C. meet at one point and their lines of action also lie on the same plane

232.	The time of flight of a projectile on downward inclined plane depends upon
A.	angle of projection
B.	angle of inclination of the plane
C.	both (a) and (b)
D.	none of these
Answer» C. both (a) and (b)

233.	Concurrent forces are those forces whose lines of action
A.	lie on the same line
B.	meet at one point
C.	meet on the same plane
D.	none of these
Answer» B. meet at one point

234.	During elastic impact, the relative velocity of the two bodies after impact is
A.	equal to
B.	equal and opposite to
C.	less than
D.	greater than
Answer» B. equal and opposite to

235.	Coefficient of friction depends upon
A.	area of contact only
B.	nature of surface only
C.	both (a) and (b)
D.	none of these
Answer» B. nature of surface only

236.	Work done is said to be zero, when
A.	some force acts on a body, but displacement is zero
B.	no force acts on a body but some displacement takes place
C.	either (a) or (b)
D.	none of the above
Answer» C. either (a) or (b)

237.	The moment of inertia of a square of side (a) about an axis through its centre of gravity is
A.	a4/4
B.	a4/8
C.	a4/12
D.	a4/36
Answer» C. a4/12

238.	When a particle moves along a straight path, there will be centripetal acceleration as well as tangential acceleration.
A.	Right
B.	Wrong
Answer» B. Wrong

239.	The motion of the body from one extremity to the other is known as a beat.
A.	Agree
B.	Disagree
Answer» A. Agree

240.	The force which acts along the radius of a circle and directed towards the centre of the circle is known as centripetal force.
A.	True
B.	False
Answer» A. True

241.	The centre of gravity of a quadrant of a circle lies along its central radius (r) at a distance of
A.	0.5 r
B.	0.6 r
C.	0.7 r
D.	0.8 r
Answer» B. 0.6 r

242.	A body is said to move or vibrate with simple harmonic motion if its acceleration is directed towards the mean position.
A.	True
B.	False
Answer» A. True

243.	The unit of energy in S.I. units is
A.	dyne
B.	watt
C.	kg – m
D.	joule
Answer» D. joule

244.	The slope on the road surface generally provided on the curves is known as
A.	angle of friction
B.	angle of repose
C.	angle of banking
D.	none of these
Answer» C. angle of banking

245.	Two balls of equal mass and of perfectly elastic material are lying on the floor. One of the ball with velocity v is made to struck the second ball. Both the balls after impact will move with a velocity
A.	v
B.	v / 2
C.	v / 4
D.	v / 8
Answer» B. v / 2

246.	According to the law of moments, if a number of coplaner forces acting on a particle are in equilibrium, then
A.	their algebraic sum is zero
B.	their lines of action are at equal distances
C.	the algebraic sum of their moments about any point in their plane is zero
D.	the algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point
Answer» C. the algebraic sum of their moments about any point in their plane is zero

247.	A force while acting on a body may
A.	change its motion
B.	balance the forces, already acting on it
C.	give rise to the internal stresses in it
D.	all of these
Answer» D. all of these

248.	For a self locking machine, the efficiency must be
A.	equal to 50%
B.	less than 50%
C.	greater than 50%
D.	100%
Answer» B. less than 50%

249.	The maximum acceleration of a particle moving with simple harmonic motion is
A.	?
B.	?r
C.	?2r
D.	?/r
Answer» C. ?2r

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