220 + Mcqs in Theory of machines Page 4 McqOptions

151.	The equivalent length of a simple pendulum depends upon the distance between the point of suspension and the centre of gravity.
A.	True
B.	False
Answer» B. False

Discussion

152.	Balancing of rotating and reciprocating parts of an engine is necessary when it runs at
A.	slow speed
B.	moderate speed
C.	highs peed
D.	any one of these
Answer» D. any one of these

Discussion

153.	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

Discussion

154.	The motion of a shaft in a circular hole is an example of
A.	completely constrained motion
B.	incompletely constrained motion
C.	successfully constrained motion
D.	none of these
Answer» C. successfully constrained motion

Discussion

155.	The acceleration of the particle moving with simple harmonic motion is __________ at the mean position.
A.	zero
B.	minimum
C.	maximum
Answer» B. minimum

Discussion

156.	In a differential band brake as shown in the below figure, if the length is greater than , then the force at should act in the downward direction.
A.	Yes
B.	No
Answer» C.

Discussion

157.	A flywheel is used to control the mean speed of an engine caused by the variations in load.
A.	Correct
B.	Incorrect
Answer» C.

Discussion

158.	A simple spring-mass vibrating system has a natural frequency of . If the spring stiffness is halved and the mass is doubled, then the natural frequency will become
A.	/2
B.	2
C.	4
D.	8
Answer» B. 2

Discussion

159.	A slider moves at a velocity on a link revolving at ω rad/s. The coriolis component of acceleration is
A.	ω
B.	2 ω
C.	ω
D.	2 ω
Answer» C. ω

Discussion

160.	The coefficient of fluctuation of energy is the ratio of maximum energy to the minimum energy.
A.	True
B.	False
Answer» C.

Discussion

161.	If the controlling force line for a spring controlled governor when produced intersects the Y-axis above the origin, then the governor is said to be unstable.
A.	Right
B.	Wrong
Answer» B. Wrong

Discussion

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

Discussion

163.	The fundamental equation for correct steering is (where φ and α = Angle through which the axis of the outer wheel and inner wheel turns respectively, = Distance between the pivots of the front axles, and = Wheel base)
A.	sin φ + sin α =
B.	cos φ - sin α =
C.	cot φ - cot α =
D.	tan φ + cot α =
Answer» D. tan φ + cot α =

Discussion

164.	A rotor supported at and carries two masses as shown in the below figure. The rotor is
A.	dynamically balanced
B.	statically balanced
C.	statically and dynamically balanced
D.	not balanced
Answer» D. not balanced

Discussion

165.	When two pulleys of different diameters are connected by means of an open belt, the angle of contact at the __________ pulley must be taken into consideration.
A.	smaller
B.	larger
Answer» B. larger

Discussion

166.	The maximum frictional force, which comes into play, when an 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» D. coefficient of friction

Discussion

167.	In a shaper mechanism, the coriolis component of acceleration does not exist.
A.	True
B.	False
Answer» C.

Discussion

168.	In a gear having involute teeth, the normal to the involute is a tangent to the
A.	pitch circle
B.	base circle
C.	addendum circle
D.	dedendum circle
Answer» C. addendum circle

Discussion

169.	A body is said to be under forced vibrations, when
A.	there is a reduction in amplitude after every cycle of vibration
B.	no external force acts on a body, after giving it an initial displacement
C.	a body vibrates under the influence of external force
D.	none of the above
Answer» D. none of the above

Discussion

170.	The natural frequency of free longitudinal vibrations is equal to (where = Mass of the body, = Stiffness of the body, and δ = Static deflection of the body)
A.	any one of these
Answer» E.

Discussion

171.	The radius of a friction circle for a shaft rotating inside a bearing is (where = Radius of shaft, and tan φ = Coefficient of friction between the shaft and bearing)
A.	sin φ
B.	cos φ
C.	tan φ
Answer» B. cos φ

Discussion

172.	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

Discussion

173.	In considering friction of a V-thread, the virtual coefficient of friction (μ) is given by
A.	μ
B.	= μ sin β
C.	μ
D.	= μ cos β
Answer» E.

Discussion

174.	The wear of bearing is proportional to velocity and pressure.
A.	Yes
B.	No
Answer» B. No

Discussion

175.	In a spring controlled governor, when the controlling force __________ as the radius of rotation increases, it is said to be a stable governor.
A.	remains constant
B.	decreases
C.	increases
Answer» D.

Discussion

176.	When the body is suspended at the point of suspension, its periodic time and frequency will be __________ as compared to the body suspended at the point of percussion.
A.	same
B.	two times
C.	four times
Answer» B. two times

Discussion

177.	A reed type tachometer use the principle of
A.	longitudinal vibration
B.	torsional vibration
C.	transverse vibration
D.	damped free vibration
Answer» D. damped free vibration

Discussion

178.	A thin circular disc is rolling with a uniform linear speed, along a straight path on a plane surface. Which of the following statement is correct in this regard ?
A.	All points of the disc have the same velocity
B.	The centre of the disc has zero acceleration
C.	The centre of the disc has centrifugal acceleration
D.	The point on the disc making contact with the plane surface has zero acceleration
Answer» C. The centre of the disc has centrifugal acceleration

Discussion

179.	In under damped vibrating system, if and are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to
A.	log
B.	log
C.	log(
D.	.
E.	)
Answer» C. log(

Discussion

180.	The angle of the inclined plane at which the body just begins to slide down the plane, is called helix angle.
A.	Right
B.	Wrong
Answer» C.

Discussion

181.	In forced vibrations, the magnitude of damping force at resonance is equal to the impressed force.
A.	Correct
B.	Incorrect
Answer» B. Incorrect

Discussion

182.	The danger of breakage and vibration is maximum
A.	below the critical speed
B.	near the critical speed
C.	above the critical speed
D.	none of these
Answer» C. above the critical speed

Discussion

183.	In a multiple V-belt drive, if one of the belt is broken, then we should replace
A.	the broken belt only
B.	all the belts
C.	the broken belt and the belts on either side of it
D.	none of the above
Answer» C. the broken belt and the belts on either side of it

Discussion

184.	A single degree of freedom system is given by , with usual notations. It represents
A.	free vibration with damping
B.	free vibration without damping
C.	forced vibration with damping
D.	forced vibration without damping
Answer» D. forced vibration without damping

Discussion

185.	When a shaking force is transmitted through the springs, damping becomes detrimental when the ratio of its frequency to the natural frequency is greater than
A.	0.25
B.	0.5
C.	1
Answer» E.

Discussion

186.	When the nature of contact between the elements of a pair is such that it can turn or revolve about a fixed axis, the pair is known as a rolling pair.
A.	Correct
B.	Incorrect
Answer» C.

Discussion

187.	In steady state forced vibrations, the amplitude of vibrations at resonance is __________ damping coefficient.
A.	equal to
B.	directly proportional to
C.	inversely proportional to
D.	independent of
Answer» D. independent of

Discussion

188.	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.
A.	Agree
B.	Disagree
Answer» B. Disagree

Discussion

189.	The frictional torque transmitted by a cone clutch is same as that of
A.	flat pivot bearing
B.	flat collar bearing
C.	conical pivot bearing
D.	truncated conical pivot bearing
Answer» E.

Discussion

190.	When two non-intersecting and non-coplaner shafts are connected by gears, the arrangement is known as helical gearing.
A.	Right
B.	Wrong
Answer» C.

Discussion

191.	In a Hartnell governor, the compression of the spring is __________ the lift of the sleeve.
A.	equal to
B.	less than
C.	greater than
Answer» B. less than

Discussion

192.	When one of the links of a kinematic chain is fixed, the chain is known as a
A.	structure
B.	mechanism
C.	inversion
D.	machine
Answer» C. inversion

Discussion

193.	The natural frequency of free transverse vibrations of a shaft fixed at both ends and carrying a uniformly distributed load is 0.571/ , where δ is the static deflection of a shaft fixed at both ends and carrying a uniformly distributed load.
A.	True
B.	False
Answer» B. False

Discussion

194.	The sensitiveness of the governor __________ as the speed range decreases.
A.	remains unaffected
B.	decreases
C.	increases
Answer» D.

Discussion

195.	For static balancing of a shaft, the net dynamic force acting on the shaft is equal to zero.
A.	Agree
B.	Disagree
Answer» B. Disagree

Discussion

196.	A spring controlled governor is said to be unstable, if the relation between the controlling force () and radius of rotation () is = .
A.	Agree
B.	Disagree
Answer» C.

Discussion

197.	The controlling force diagram for a spring controlled governor is a curve passing through the origin.
A.	Yes
B.	No
Answer» C.

Discussion

198.	Most of the engines, generally, do not require balancing of secondary forces and couples.
A.	Right
B.	Wrong
Answer» B. Wrong

Discussion

199.	The essential condition of placing the two masses, so that the system becomes dynamically equivalent, is (where and = Distance of two masses from the centre of gravity of the body, and = Radius of gyration of the body)
A.	=
B.	=
C.	=
D.	=
Answer» E.

Discussion

200.	The secondary unbalanced force is maximum __________ in one revolution of the crank.
A.	two times
B.	four times
C.	eight times
D.	sixteen times
Answer» C. eight times

Discussion

Explore topic-wise MCQs in Mechanical Engineering.

The equivalent length of a simple pendulum depends upon the distance between the point of suspension and the centre of gravity.

Balancing of rotating and reciprocating parts of an engine is necessary when it runs at

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 motion of a shaft in a circular hole is an example of

The acceleration of the particle moving with simple harmonic motion is __________ at the mean position.

In a differential band brake as shown in the below figure, if the length is greater than , then the force at should act in the downward direction.

A flywheel is used to control the mean speed of an engine caused by the variations in load.

A simple spring-mass vibrating system has a natural frequency of . If the spring stiffness is halved and the mass is doubled, then the natural frequency will become

A slider moves at a velocity on a link revolving at ω rad/s. The coriolis component of acceleration is

The coefficient of fluctuation of energy is the ratio of maximum energy to the minimum energy.

If the controlling force line for a spring controlled governor when produced intersects the Y-axis above the origin, then the governor is said to be unstable.

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

The fundamental equation for correct steering is (where φ and α = Angle through which the axis of the outer wheel and inner wheel turns respectively, = Distance between the pivots of the front axles, and = Wheel base)

A rotor supported at and carries two masses as shown in the below figure. The rotor is

When two pulleys of different diameters are connected by means of an open belt, the angle of contact at the __________ pulley must be taken into consideration.

The maximum frictional force, which comes into play, when an body just begins to slide over the surface of the other body, is known as

In a shaper mechanism, the coriolis component of acceleration does not exist.

In a gear having involute teeth, the normal to the involute is a tangent to the

A body is said to be under forced vibrations, when

The natural frequency of free longitudinal vibrations is equal to (where = Mass of the body, = Stiffness of the body, and δ = Static deflection of the body)

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

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

In considering friction of a V-thread, the virtual coefficient of friction (μ) is given by

The wear of bearing is proportional to velocity and pressure.

In a spring controlled governor, when the controlling force __________ as the radius of rotation increases, it is said to be a stable governor.

When the body is suspended at the point of suspension, its periodic time and frequency will be __________ as compared to the body suspended at the point of percussion.

A reed type tachometer use the principle of

A thin circular disc is rolling with a uniform linear speed, along a straight path on a plane surface. Which of the following statement is correct in this regard ?

In under damped vibrating system, if and are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to

The angle of the inclined plane at which the body just begins to slide down the plane, is called helix angle.

In forced vibrations, the magnitude of damping force at resonance is equal to the impressed force.

The danger of breakage and vibration is maximum

In a multiple V-belt drive, if one of the belt is broken, then we should replace

A single degree of freedom system is given by , with usual notations. It represents

When a shaking force is transmitted through the springs, damping becomes detrimental when the ratio of its frequency to the natural frequency is greater than

When the nature of contact between the elements of a pair is such that it can turn or revolve about a fixed axis, the pair is known as a rolling pair.

In steady state forced vibrations, the amplitude of vibrations at resonance is __________ damping coefficient.

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 frictional torque transmitted by a cone clutch is same as that of

When two non-intersecting and non-coplaner shafts are connected by gears, the arrangement is known as helical gearing.

In a Hartnell governor, the compression of the spring is __________ the lift of the sleeve.

When one of the links of a kinematic chain is fixed, the chain is known as a

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

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

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

A spring controlled governor is said to be unstable, if the relation between the controlling force () and radius of rotation () is = .

The controlling force diagram for a spring controlled governor is a curve passing through the origin.

Most of the engines, generally, do not require balancing of secondary forces and couples.

The essential condition of placing the two masses, so that the system becomes dynamically equivalent, is (where and = Distance of two masses from the centre of gravity of the body, and = Radius of gyration of the body)

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