The magnitude of velocities of the points on a rigid link is

directly proportional to the distance from the points to the instantaneous centre and is parallel to the line joining the point to the instantaneous centre

directly proportional to the distance from the points to the instantaneous centre and is perpendicular to the line joining the point to the instantaneous centre

inversely proportional to the distance from the points to the instantaneous centre and is parallel to the line joining the point to the instantaneous centre

inversely proportional to the distance from the points to the instantaneous centre and is perpendicular to the line joining the point to the instantaneous centre

Which of the following is an example of sliding pair?

Shaft with collars at both ends fitted into a circular hole

Piston and cylinder of a reciprocating steam engine

Shaft with collars at both ends fitted into a circular hole

A spring controlled governor is said to be isochronous when the controlling force

increases as the radius of rotation decreases

increases as the radius of rotation increases

decreases as the radius of rotation increases

remains constant for all radii of rotation

A system in dynamic balance implies that

there will absolutely no wear of bearings

the system is critically damped

there is no critical speed in the system

the system is also statically balanced

there will absolutely no wear of bearings

Which of the following statement is correct for gears ?

The addendum is less than the dedendum

The pitch circle diameter is the product of module and number of teeth

The contact ratio means the number of pairs of teeth in contact

Which of the following statements regarding laws governing the friction between dry surfaces are correct?

The friction force is dependent on the materials of the contact surfaces.

The friction force is directly proportional to the normal force.

The friction force is independent of me area of contact.

The frictional torque transmitted by a disc or plate clutch is same as that of

truncated conical pivot bearing

Critical damping is a function of

damping coefficient and natural frequency

The centrifugal tension in belts

increases power transmitted upto a certain speed and then decreases

have no effect on power transmitted

increases power transmitted upto a certain speed and then decreases

A system of masses rotating in different parallel planes is in dynamic balance if the

resultant force is numerically equal to the resultant couple, but neither of them need necessarily be zero

resultance force is equal to zero

resultant couple is equal to zero

resultant force and resultant couple are both equal to zero

resultant force is numerically equal to the resultant couple, but neither of them need necessarily be zero

The contact ratio is the ratio of

length of arc of approach to the circular pitch

length of pair of contact to the circular pitch

length of arc of contact to the circular pitch

length of arc of approach to the circular pitch

length of arc of recess to the circular pitch

For dynamic balancing of a shaft

the net dynamic force acting on the shaft is equal to zero

the net couple due to the dynamic forces acting on the shaft is equal to zero

In a cone pulley, if the sum of radii of the pulleys on the driving and driven shafts is Constant, then

both open belt drive and crossed belt drive is recommended

crossed belt drive is recommended

both open belt drive and crossed belt drive is recommended

the drive is recommended depending upon the torque transmitted

In a band and block brake, the ratio of tensions on tight side and slack side of the band is (where μ = Coefficient of friction between the blocks and the drum, θ = Semi-angle of each block subtending at the centre of drum, and n = Number of blocks)

T₁/T₂ = [(1 - μ tanθ)/ (1 + μ tanθ)]n

T₁/T₂ = [(1 + μ tanθ)/ (1 - μ tanθ)]n

470 + Mcqs in Theory of machines in Automobile Engineering Page 2 McqOptions

51.	The magnitude of velocities of the points on a rigid link is
A.	directly proportional to the distance from the points to the instantaneous centre and is parallel to the line joining the point to the instantaneous centre
B.	directly proportional to the distance from the points to the instantaneous centre and is perpendicular to the line joining the point to the instantaneous centre
C.	inversely proportional to the distance from the points to the instantaneous centre and is parallel to the line joining the point to the instantaneous centre
D.	inversely proportional to the distance from the points to the instantaneous centre and is perpendicular to the line joining the point to the instantaneous centre
Answer» E.

52.	When the nature of contact between the elements of a pair is such that it can only slide relative to the other, the pair is known as a
A.	screw pair
B.	spherical pair
C.	turning pair
D.	sliding pair
Answer» E.

53.	In a reciprocating engine, usually __________ of the reciprocating masses are balanced.
A.	one-half
B.	two-third
C.	three-fourth
D.	whole
Answer» C. three-fourth

54.	For static balancing of a shaft, the net dynamic force acting on the shaft is equal to zero.
A.	Agree
B.	Disagree
C.	Can't say
D.	None of these
Answer» B. Disagree

56.	The sensitiveness of the governor __________ as the speed range decreases.
A.	remains unaffected
B.	decreases
C.	increases
D.	None of these
Answer» D. None of these

58.	The unbalanced primary forces in a reciprocating engine are
A.	balanced completely
B.	balanced partially
C.	balanced by secondary forces
D.	not balanced
Answer» C. balanced by secondary forces

60.	The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as
A.	damping factor
B.	damping coefficient
C.	logarithmic decrement
D.	magnification factor
Answer» E.

62.	When no external force acts on a body, after giving it an initial displacement, the body is said to have free vibrations.
A.	True
B.	False
C.	Can't say
D.	None of these
Answer» B. False

64.	The relative velocity of B with respect to A in a rigid link AB is
A.	parallel to AB
B.	perpendicular to AB
C.	along AB
D.	at 45° to AB
Answer» C. along AB

65.	The equation of motion for a vibrating system with viscous damping is If the roots of this equation are real, then the system will be
A.	overdamped
B.	under damped
C.	critically damped
D.	without vibrations
Answer» B. under damped

66.	The frictional torque transmitted by a disc or plate clutch is same as that of
A.	flat pivot bearing
B.	flat collar bearing
C.	conical pivot bearing
D.	truncated conical pivot bearing
Answer» C. conical pivot bearing

73.	The piston slide valve is an inside admission valve.
A.	Yes
B.	No
C.	Can't say
D.	None of these
Answer» B. No

75.	The relation between number of pairs (p) forming a kinematic chain and the number of links (l) is
A.	l = 2p - 2
B.	l = 2p - 3
C.	l = 2p - 4
D.	l = 2p - 5
Answer» D. l = 2p - 5

76.	A rotor which is balanced statically but not dynamically is supported on two bearings L apart and at high speed of the rotor, reaction on the left bearing is R. The right side of the bearing is shifted to a new position 2 L apart from the left bearing. At the same rotor speed, dynamic reaction on the left bearing in the new arrangement will
A.	remain same as before
B.	become equal to 2 R
C.	become equal to R/2
D.	become equal to R/4
Answer» B. become equal to 2 R

80.	The velocity of a flat-faced follower when it has contact with the flank of a circular arc cam, is given by
A.	ωR cos θ
B.	ω(R - r1)cos θ
C.	ω(R - r1)sin θ
D.	ωr1 sin θ
Answer» D. ωr1 sin θ

67.	Critical damping is a function of
A.	mass and stiffness
B.	mass and damping coefficient
C.	mass and natural frequency
D.	damping coefficient and natural frequency
Answer» B. mass and damping coefficient

68.	The centrifugal tension in belts
A.	increases power transmitted
B.	decreases power transmitted
C.	have no effect on power transmitted
D.	increases power transmitted upto a certain speed and then decreases
Answer» D. increases power transmitted upto a certain speed and then decreases

69.	If the number of links in a mechanism are equal to l, then the number of possible inversions are equal to
A.	l - 2
B.	l - 1
C.	l
D.	l + 1
Answer» D. l + 1

70.	The tangential component of acceleration of the slider with respect to the coincident point on the link is called coriolis component of acceleration.
A.	Agree
B.	Disagree
C.	Can't say
D.	None of these
Answer» B. Disagree

71.	The wear of bearing is proportional to velocity and pressure.
A.	Yes
B.	No
C.	Can't say
D.	None of these
Answer» B. No

72.	The cam and follower is an example of
A.	sliding pair
B.	rolling pair
C.	lower pair
D.	higher pair
Answer» E.

78.	The inertia force is equal to the accelerating force in magnitude, but opposite in direction.
A.	Right
B.	Wrong
C.	Can't say
D.	None of these
Answer» B. Wrong

79.	In a Proell governor, the balls are attached to the extension of lower links.
A.	True
B.	False
C.	Can't say
D.	None of these
Answer» B. False

82.	The radial distance from the top of a tooth to the bottom of a tooth in a meshing gear, is called
A.	dedendum
B.	addendum
C.	clearance
D.	working depth
Answer» D. working depth

83.	The radius of a friction circle for a shaft rotating inside a bearing is (where r = Radius of shaft, and tan φ = Coefficient of friction between the shaft and bearing)
A.	r sin φ
B.	r cos φ
C.	r tan φ
D.	None of these
Answer» B. r cos φ

Explore topic-wise MCQs in Automobile Engineering.

The magnitude of velocities of the points on a rigid link is

When the nature of contact between the elements of a pair is such that it can only slide relative to the other, the pair is known as a

In a reciprocating engine, usually __________ of the reciprocating masses are balanced.

For static balancing of a shaft, the net dynamic force acting on the shaft is equal to zero.

Which of the following is an example of sliding pair?

The sensitiveness of the governor __________ as the speed range decreases.

A spring controlled governor is said to be isochronous when the controlling force

The unbalanced primary forces in a reciprocating engine are

A system in dynamic balance implies that

The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as

Which of the following statement is correct for gears ?

When no external force acts on a body, after giving it an initial displacement, the body is said to have free vibrations.

Which of the following statements regarding laws governing the friction between dry surfaces are correct?

The relative velocity of B with respect to A in a rigid link AB is

The equation of motion for a vibrating system with viscous damping is If the roots of this equation are real, then the system will be

The frictional torque transmitted by a disc or plate clutch is same as that of

Critical damping is a function of

The centrifugal tension in belts

If the number of links in a mechanism are equal to l, then the number of possible inversions are equal to

The tangential component of acceleration of the slider with respect to the coincident point on the link is called coriolis component of acceleration.

The wear of bearing is proportional to velocity and pressure.

The cam and follower is an example of

The piston slide valve is an inside admission valve.

A system of masses rotating in different parallel planes is in dynamic balance if the

The relation between number of pairs (p) forming a kinematic chain and the number of links (l) is

The contact ratio is the ratio of

The inertia force is equal to the accelerating force in magnitude, but opposite in direction.

In a Proell governor, the balls are attached to the extension of lower links.

The velocity of a flat-faced follower when it has contact with the flank of a circular arc cam, is given by

For dynamic balancing of a shaft

The radial distance from the top of a tooth to the bottom of a tooth in a meshing gear, is called

The radius of a friction circle for a shaft rotating inside a bearing is (where r = Radius of shaft, and tan φ = Coefficient of friction between the shaft and bearing)

The acceleration of the reciprocating roller follower when it has contact with the straight flanks of the tangent cam, is given by

The natural frequency of free transverse vibrations of a shaft fixed at both ends and carrying a uniformly distributed load is 0.571/δS , where δS is the static deflection of a shaft fixed at both ends and carrying a uniformly distributed load.

The primary unbalanced force is maximum __________ in one revolution of the crank.

The frictional torque transmitted in a conical pivot bearing with assumption of uniform pressure is __________ as compared to uniform wear.

A railway bridge is an example of a machine.

When brakes are applied to all the four wheels of a moving car, the distance travelled by the car before it is brought to rest, will be

In a screw jack, the effort required to lift the load W is given by (where α = Helix angle, and φ = Angle of friction)

In a cone pulley, if the sum of radii of the pulleys on the driving and driven shafts is Constant, then

In a steam engine, the earlier cut-off with a simple slide valve may be obtained by increasing the angle of advance of the eccentric but reducing the throw of the eccentric and keeping the steam lap and exhaust lap constant. This method will cause withdrawing or throttling of steam.

The velocity of piston in a reciprocating steam engine is given by (where ω = Angular velocity of crank, r = Radius of crank pin circle, θ = Angle turned by crank from inner dead centre, and n = Ratio of length of connecting rod to the radius of crank)

The ratio of height of Porter governor (when length of arms and links are equal) to the height of Watt's governor is (where m = Mass of the ball, and M = Mass on the sleeve)

In a band and block brake, the ratio of tensions on tight side and slack side of the band is (where μ = Coefficient of friction between the blocks and the drum, θ = Semi-angle of each block subtending at the centre of drum, and n = Number of blocks)

The velocity of a particle moving with simple harmonic motion, at any instant is given by (where ω = Displacement of the particle from mean position)

In Meyer's expansion valve, the main valve is driven by an eccentric having an angle of advance from

A very sensitive governor will cause hunting.

The virtual or equivalent eccentric for the Meyer's expansion valve is defined as an eccentric having such a length and angle of advance that will cause cut-off to take place at the same position, as is caused by the combined effect of main eccentric and expansion eccentric.

When a slider moves on a fixed link having curved surface, their instantaneous centre lies

84.	The acceleration of the reciprocating roller follower when it has contact with the straight flanks of the tangent cam, is given by
A.	ω²(r1 - r2)(1 - cos2θ)
B.	ω²(r1 + r2)(1 + cos2θ)
C.	ω²(r1 + r2)
D.	ω²(r1 - r2)(1 - sin² θ)
Answer» D. ω²(r1 - r2)(1 - sin² θ)

86.	The primary unbalanced force is maximum __________ in one revolution of the crank.
A.	twice
B.	four times
C.	eight times
D.	sixteen times
Answer» B. four times

87.	The frictional torque transmitted in a conical pivot bearing with assumption of uniform pressure is __________ as compared to uniform wear.
A.	less
B.	more
C.	same
D.	None of these
Answer» C. same

89.	When brakes are applied to all the four wheels of a moving car, the distance travelled by the car before it is brought to rest, will be
A.	maximum
B.	minimum
C.	zero
D.	None of these
Answer» C. zero

90.	In a screw jack, the effort required to lift the load W is given by (where α = Helix angle, and φ = Angle of friction)
A.	P = W tan(α - φ)
B.	P = W tan(α + φ)
C.	P = W tan(φ - α)
D.	P = W cos(α + φ)
Answer» C. P = W tan(φ - α)

91.	In a cone pulley, if the sum of radii of the pulleys on the driving and driven shafts is Constant, then
A.	open belt drive is recommended
B.	crossed belt drive is recommended
C.	both open belt drive and crossed belt drive is recommended
D.	the drive is recommended depending upon the torque transmitted
Answer» C. both open belt drive and crossed belt drive is recommended

93.	The velocity of piston in a reciprocating steam engine is given by (where ω = Angular velocity of crank, r = Radius of crank pin circle, θ = Angle turned by crank from inner dead centre, and n = Ratio of length of connecting rod to the radius of crank)
A.	ωr [sin θ + (sin 2θ/n)]
B.	ωr [cos θ + (cos 2θ/n)]
C.	ω²r [sin θ + (sin 2θ/n)]
D.	ω²r [cos θ + (cos 2θ/n)]
Answer» B. ωr [cos θ + (cos 2θ/n)]

94.	The ratio of height of Porter governor (when length of arms and links are equal) to the height of Watt's governor is (where m = Mass of the ball, and M = Mass on the sleeve)
A.	m/(m + M)
B.	M/(m + M)
C.	(m + M)/m
D.	(m + M)/M
Answer» D. (m + M)/M

95.	In a band and block brake, the ratio of tensions on tight side and slack side of the band is (where μ = Coefficient of friction between the blocks and the drum, θ = Semi-angle of each block subtending at the centre of drum, and n = Number of blocks)
A.	T₁/T₂ = μθ × n
B.	T₁/T₂ = (μθ)n
C.	T₁/T₂ = [(1 - μ tanθ)/ (1 + μ tanθ)]n
D.	T₁/T₂ = [(1 + μ tanθ)/ (1 - μ tanθ)]n
Answer» E.

96.	The velocity of a particle moving with simple harmonic motion, at any instant is given by (where ω = Displacement of the particle from mean position)
A.	ω √(r² - x²)
B.	ω √(x² - r²)
C.	ω² √(x² - r²)
D.	ω² √(r² - x²)
Answer» B. ω √(x² - r²)