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

principle of conservation of energy

principle of conservation of momentum

83 + Mcqs in General in Engineering Mechanics Page 2 McqOptions

51.	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» C.

Discussion

52.	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» B. cos ?

Discussion

53.	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» B. less than

Discussion

54.	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» B. 20 N and 5 N

Discussion

55.	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» B. 40N

Discussion

56.	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» B. FALSE

Discussion

57.	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» E.

Discussion

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

Discussion

59.	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» C.

Discussion

60.	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» B. No

Discussion

61.	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» E.

Discussion

62.	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» B. six times

Discussion

63.	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» C.

Discussion

64.	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» C.

Discussion

65.	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» B. mr2 / 4

Discussion

66.	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» E.

Discussion

67.	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» E.

Discussion

68.	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» B. T.? / 60 (in watts)

Discussion

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

Discussion

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

Discussion

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

Discussion

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

Discussion

73.	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» C. a = r / ?

Discussion

74.	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» B. False

Discussion

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

Discussion

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

Discussion

77.	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» D.

Discussion

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

Discussion

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

Discussion

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

Discussion

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

Discussion

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

Discussion

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

Discussion

Explore topic-wise MCQs in Engineering Mechanics.

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

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

The force required to move the body up the plane will be minimum if it makes an angle with the inclined plane

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

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 resultant force is a single force which produces the same effect as produced by all the given forces acting on a body

If the resultant of two equal forces has the same magnitude as either of the forces, then angle between the two forces is

If the efficiency of a lifting machine is kept constant, its velocity ratio is

If the resultant of a number of forces acting on a body is zero, then the body will not be in equilibrium

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

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

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 machine which is capable of doing any work in the reversed direction, after the effort is removed, is called a reversible machine.

A machine which is capable of doing work in the reversed direction, after the effort is re-moved, is called a non-reversible machine.

The moment of inertia of a solid cylinder of mass m, radius r and length l about the longitudenal axis or polar axis is

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

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

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 smooth cylinder lying on a

If a pendulum is taken 1 km below the earth surface in a mine, it will

The acceleration of a particle moving with simple harmonic motion is

Tension in the cable supporting a lift is more when the lift is moving

The linear acceleration (a) of a body rotating along a circular path of radius (r) with an angular acceleration of ? rad / s2, is

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

When the lift is moving upwards with some acceleration, the pressure exerted by a man is

The impact between two lead spheres is approximately equal to an

A body will begin to move down an inclined plane if the angle of inclination of the plane is

The range of projectile on a downward inclined plane is

If a given force (or a given system of forces) acting on a body

The loss of kinetic energy due to direct impact of two bodies

A non-reversible machine is also called a self-locking machine

A smooth cylinder lying on its convex surface remains in

In actual machines, mechanical advantage is