Open pairs are those which have

Two elements that permit relative motion

Point or line contact between the two elements when in motion

Surface contact between the two elements when in motion

Elements of pairs not held together mechanically

Two elements that permit relative motion

A body is said to be under forced vibrations, when

No external force acts on a body, after giving it an initial displacement

There is a reduction in amplitude after every cycle of vibration

No external force acts on a body, after giving it an initial displacement

A body vibrates under the influence of external force

The frictional torque transmitted in a truncated conical pivot bearing, considering uniform wear, is

(2/3).μ W cosec α (r₁ + r₂)

(1/2). μ W cosec α (r₁ + r₂)

(2/3).μ W cosec α (r₁ + r₂)

(1/2). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]

(2/3). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]

The C.G. of a link in any mechanism would experience

Both angular and linear accelerations

A point B on a rigid link AB moves with respect to A with angular velocity ω rad/s. The total acceleration of B with respect to A will be equal to

Vector difference of radial component and tangential component

Vector sum of radial component and Coriolis component

Vector sum of tangential component and Coriolis component

Vector sum of radial component and tangential component

Vector difference of radial component and tangential component

Power of a governor is the

Mean force exerted at the sleeve for a given percentage change of speed

Work-done at the sleeve for maximum equilibrium speed

Mean force exerted at the sleeve for maximum equilibrium speed

Effort of a governor is the

Work-done at the sleeve for maximum equilibrium speed

Mean force exerted at the sleeve for a given percentage change of speed

Work-done at the sleeve for maximum equilibrium speed

Mean force exerted at the sleeve for maximum equilibrium speed

The maximum efficiency of spiral gears is (where θ = Shaft angle, and φ = Friction angle)

cos (θ - φ) + 1/ cos (θ + φ) + 1

sin (θ + φ) + 1/ cos (θ - φ) + 1

cos (θ - φ) + 1/ sin (θ + φ) + 1

cos (θ + φ) + 1/ cos (θ - φ) + 1

cos (θ - φ) + 1/ cos (θ + φ) + 1

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 instantaneous center of a rigid thin disc rolling on a plane rigid surface is located at

An infinite distance on the plane surface

The point on the circumference situated vertically opposite to the contact point

The Coriolis component of acceleration acts

Perpendicular to the sliding surface

Parallel to the sliding surface

In a four bar chain or quadric cycle chain

One is a turning pair and three are sliding pairs

Each of the four pairs is a turning pair

One is a turning pair and three are sliding pairs

Two are turning pairs and two are sliding pairs

Three are turning pairs and one is a sliding pair

The example of successfully constrained motion is a

Motion of the shaft between a footstep bearing

Piston reciprocating inside an engine cylinder

The example of completely constrained motion is a

Motion of a piston in the cylinder of a steam engine

Motion of a square bar in a square hole

Motion of a shaft with collars at each end in a circular hole

A rigid body, under the action of external forces, can be replaced by two masses placed at a fixed distance apart. The two masses form an equivalent dynamical system, if

The sum of the two masses is equal to the total mass of body

The center of gravity of the two masses coincides with that of the body

The sum of mass moment of inertia of the masses about their center of gravity is equal to the mass moment of inertia of the body

If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then energy stored in the latter at the same speed will be

One and a half times the first one

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

Which is the false statement about the properties of instantaneous center?

At the instantaneous center of rotation, one rigid link rotates instantaneously relative to another for the configuration of mechanism considered

The two rigid links have no linear velocities relative to each other at the instantaneous center

The two rigid links which have no linear velocity relative to each other at this center have the same linear velocity to the third rigid link

The double center can be denoted either by O2 or O12, but proper selection should be made

977 + Mcqs in Theory Of Machine in Mechanical Engineering Page 3 McqOptions

101.	When the two elements of a pair have __________ when in motion, it is said to a lower pair.
A.	Line or point contact
B.	Surface contact
C.	Body contact
D.	None of these
Answer» C. Body contact

Discussion

102.	Open pairs are those which have
A.	Point or line contact between the two elements when in motion
B.	Surface contact between the two elements when in motion
C.	Elements of pairs not held together mechanically
D.	Two elements that permit relative motion
Answer» D. Two elements that permit relative motion

Discussion

103.	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» B. No external force acts on a body, after giving it an initial displacement

Discussion

104.	V-belts are usually used for
A.	Long drives
B.	Short drives
C.	Long and short drives
D.	None of these
Answer» C. Long and short drives

Discussion

105.	Scotch yoke mechanism is used to generate
A.	Sine functions
B.	Square roots
C.	Logarithms
D.	Inversions
Answer» B. Square roots

Discussion

106.	The frictional torque transmitted in a truncated conical pivot bearing, considering uniform wear, is
A.	(1/2). μ W cosec α (r₁ + r₂)
B.	(2/3).μ W cosec α (r₁ + r₂)
C.	(1/2). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]
D.	(2/3). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]
Answer» B. (2/3).μ W cosec α (r₁ + r₂)

Discussion

107.	The frictional torque transmitted in a conical pivot bearing, considering uniform wear, is
A.	(1/2) μ W R cosecα
B.	(2/3) μ W R cosecα
C.	(3/4) μ W R cosecα
D.	μ W R cosecα
Answer» B. (2/3) μ W R cosecα

Discussion

108.	The frictional torque transmitted in a flat 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

Discussion

109.	The condition for correct steering of a Davis steering gear is (where α = Angle of inclination of the links to the vertical)
A.	sinα = b/c
B.	cosα = c/b
C.	tanα = c/2b
D.	cotα = c/2b
Answer» D. cotα = c/2b

Discussion

110.	There are six gears A, B, C, D, E and F in a compound train. The numbers of teeth in the gears are 20, 60, 30, 80, 25 and 75 respectively. The ratio of angular speeds of the driven (F) to the driver (A) of the drive is
A.	1/24
B.	1/8
C.	4/15
D.	12
Answer» B. 1/8

Discussion

111.	The C.G. of a link in any mechanism would experience
A.	No acceleration
B.	Linear acceleration
C.	Angular acceleration
D.	Both angular and linear accelerations
Answer» E.

Discussion

112.	The lead screw of a lathe with nut forms a
A.	Rolling pair
B.	Sliding pair
C.	Screw pair
D.	Turning pair
Answer» D. Turning pair

Discussion

113.	A point B on a rigid link AB moves with respect to A with angular velocity ω rad/s. The total acceleration of B with respect to A will be equal to
A.	Vector sum of radial component and Coriolis component
B.	Vector sum of tangential component and Coriolis component
C.	Vector sum of radial component and tangential component
D.	Vector difference of radial component and tangential component
Answer» D. Vector difference of radial component and tangential component

Discussion

114.	A mechanism consisting of four links is called a __________ mechanism.
A.	Simple
B.	Compound
C.	Binary
D.	None of these
Answer» B. Compound

Discussion

115.	A rotary internal combustion engine has __________ cylinders.
A.	Four
B.	Five
C.	Six
D.	Seven
Answer» E.

Discussion

116.	When two pulleys are connected by means of a cross belt drive, then both the pulleys will rotate in _________ directions.
A.	Same
B.	Opposite
C.	Perpendicular
D.	None of these
Answer» C. Perpendicular

Discussion

117.	In a rigid link OA, velocity of 'A' w.r.t. 'O' will be
A.	Parallel to OA
B.	Perpendicular to OA
C.	At 45° to OA
D.	Along AO
Answer» C. At 45° to OA

Discussion

118.	Power of a governor is the
A.	Mean force exerted at the sleeve for a given percentage change of speed
B.	Work-done at the sleeve for maximum equilibrium speed
C.	Mean force exerted at the sleeve for maximum equilibrium speed
D.	None of the above
Answer» E.

Discussion

119.	Effort of a governor is the
A.	Mean force exerted at the sleeve for a given percentage change of speed
B.	Work-done at the sleeve for maximum equilibrium speed
C.	Mean force exerted at the sleeve for maximum equilibrium speed
D.	None of the above
Answer» B. Work-done at the sleeve for maximum equilibrium speed

Discussion

120.	When the addenda on pinion and wheel is such that the path of approach and path of recess are half of their maximum possible values, then the length of the path of contact is given by (where r = Pitch circle radius of pinion, R = Pitch circle radius of wheel, and φ = Pressure angle)
A.	[(r² + R²) cosφ]/2
B.	[(r² + R²) sinφ]/2
C.	[(r + R) cosφ]/2
D.	[(r + R) sinφ]/2
Answer» E.

Discussion

121.	The dedendum circle diameter is equal to (where, φ = Pressure angle)
A.	Pitch circle dia. × cosφ
B.	Addendum circle dia. × cosφ
C.	Clearance circle dia. × cosφ
D.	Pitch circle dia. × sinφ
Answer» B. Addendum circle dia. × cosφ

Discussion

122.	The maximum efficiency of spiral gears is (where θ = Shaft angle, and φ = Friction angle)
A.	sin (θ + φ) + 1/ cos (θ - φ) + 1
B.	cos (θ - φ) + 1/ sin (θ + φ) + 1
C.	cos (θ + φ) + 1/ cos (θ - φ) + 1
D.	cos (θ - φ) + 1/ cos (θ + φ) + 1
Answer» D. cos (θ - φ) + 1/ cos (θ + φ) + 1

Discussion

123.	Which of the following statements regarding laws governing the friction between dry surfaces are correct?
A.	The friction force is dependent on the materials of the contact surfaces.
B.	The friction force is directly proportional to the normal force.
C.	The friction force is independent of me area of contact.
D.	All of the above
Answer» E.

Discussion

124.	The instantaneous center of a rigid thin disc rolling on a plane rigid surface is located at
A.	The center of the disc
B.	The point of contact
C.	An infinite distance on the plane surface
D.	The point on the circumference situated vertically opposite to the contact point
Answer» C. An infinite distance on the plane surface

Discussion

125.	In a shaper mechanism, the Coriolis component of acceleration will
A.	Not exist
B.	Exist
C.	Depend on position of crank
D.	None of the above
Answer» C. Depend on position of crank

Discussion

126.	The Coriolis component of acceleration acts
A.	Along the sliding surface
B.	Perpendicular to the sliding surface
C.	At 45° to the sliding surface
D.	Parallel to the sliding surface
Answer» C. At 45° to the sliding surface

Discussion

127.	In a four bar chain or quadric cycle chain
A.	Each of the four pairs is a turning pair
B.	One is a turning pair and three are sliding pairs
C.	Two are turning pairs and two are sliding pairs
D.	Three are turning pairs and one is a sliding pair
Answer» B. One is a turning pair and three are sliding pairs

Discussion

128.	The frictional torque transmitted in a flat pivot bearing, assuming uniform wear, is(Where μ = Coefficient of friction, W=Load over the bearing, R=Radius of bearing)
A.	μwr
B.	¾μWR
C.	²/₃ μWR
D.	½μWR
Answer» E.

Discussion

129.	For an involute gear, the ratio of base circle radius and pitch circle radius is equal to
A.	sinφ
B.	cosφ
C.	secφ
D.	cosecφ
Answer» C. secφ

Discussion

130.	In vibration isolation system, the transmissibility will be equal to unity, for all values of damping factor, if ω/ωn is
A.	Equal to 1
B.	Equal to 2
C.	Less than 2
D.	Greater than 2
Answer» C. Less than 2

Discussion

131.	The example of successfully constrained motion is a
A.	Motion of an I.C. engine valve
B.	Motion of the shaft between a footstep bearing
C.	Piston reciprocating inside an engine cylinder
D.	All of the above
Answer» E.

Discussion

132.	The example of completely constrained motion is a
A.	Motion of a piston in the cylinder of a steam engine
B.	Motion of a square bar in a square hole
C.	Motion of a shaft with collars at each end in a circular hole
D.	All of the above
Answer» E.

Discussion

133.	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

134.	A body having moment of inertia o:m2 is rotating at 210 RPM and r with another body at rest having I 40 kg m2. The resultant speed after ing will be
A.	90 RPM
B.	100 RPM
C.	80 RPM
D.	data are insufficient
Answer» B. 100 RPM

Discussion

135.	A torsional system with discs of moment of inertia I₁ and I₂ as shown in the below figure, is gear driven such that the ratio of speed of shaft B to shaft A is 'G'. Neglecting the inertia of gears, the equivalent inertia of disc on shaft B at the speed of shaft A is equal to
A.	G.I₂
B.	G².I₂
C.	I₂/G
D.	I₂/G²
Answer» C. I₂/G

Discussion

136.	In a pantograph, all the pairs are
A.	Turning pairs
B.	Sliding pairs
C.	Spherical pairs
D.	Self-closed pairs
Answer» B. Sliding pairs

Discussion

137.	The mechanism in which two are turning pairs and two are sliding pairs, is called a
A.	Double slider crank chain
B.	Elliptical trammel
C.	Scotch yoke mechanism
D.	All of these
Answer» E.

Discussion

138.	The main disadvantage of the sliding pair is that it is
A.	Bulky
B.	Wears rapidly
C.	Difficult to manufacture
D.	Both (A) and (B) above
Answer» E.

Discussion

139.	Cylindrical cams can be classified as
A.	Circular
B.	Tangent
C.	Reciprocating
D.	None of the above
Answer» E.

Discussion

140.	A circle passing through the pitch point with its center at the center of cam axis is known as
A.	Pitch circle
B.	Base circle
C.	Prime circle
D.	Outer circle
Answer» D. Outer circle

Discussion

141.	The frequency of damped vibrations with viscous damping is ________ the frequency of undamped vibrations.
A.	More than
B.	Less than
C.	Same as
D.	None of these
Answer» C. Same as

Discussion

142.	A rigid body, under the action of external forces, can be replaced by two masses placed at a fixed distance apart. The two masses form an equivalent dynamical system, if
A.	The sum of the two masses is equal to the total mass of body
B.	The center of gravity of the two masses coincides with that of the body
C.	The sum of mass moment of inertia of the masses about their center of gravity is equal to the mass moment of inertia of the body
D.	All of the above
Answer» E.

Discussion

143.	If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then energy stored in the latter at the same speed will be
A.	Four times the first one
B.	Same as the first one
C.	One fourth of the first one
D.	One and a half times the first one
Answer» D. One and a half times the first one

Discussion

144.	Frequency of vibrations is usually expressed in
A.	Number of cycles per hour
B.	Number of cycles per minute
C.	Number of cycles per second
D.	None of these
Answer» D. None of these

Discussion

145.	A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by (where μ = tan φ = Coefficient of friction between the plane and the body)
A.	P = W tan α
B.	P = W tan (α + φ)
C.	P = W (sin α + μ cos α)
D.	P = W (cos α + μ sin α)
Answer» D. P = W (cos α + μ sin α)

Discussion

146.	A slider crank chain consists of following numbers of turning and sliding pairs
A.	1, 3
B.	2, 2
C.	3, 1
D.	4, 0
Answer» D. 4, 0

Discussion

147.	Cross head and guides form a
A.	Lower pair
B.	Higher pair
C.	Turning pair
D.	Sliding pair
Answer» E.

Discussion

148.	For dynamic balancing of a shaft
A.	The net dynamic force acting on the shaft is equal to zero
B.	The net couple due to the dynamic forces acting on the shaft is equal to zero
C.	Both (A) and (B)
D.	None of the above
Answer» D. None of the above

Discussion

149.	In a Hartnell governor, the lift of the sleeve is given by (where r₁ and r₂ = Max. and min. radii of rotation, x = Length of ball arm of the lever, and y = Length of sleeve arm of the lever)
A.	(r₁ + r₂) (y/x)
B.	(r₁ + r₂) (x/y)
C.	(r₁ - r₂) (y/x)
D.	(r₁ - r₂) (x/y)
Answer» D. (r₁ - r₂) (x/y)

Discussion

150.	Which is the false statement about the properties of instantaneous center?
A.	At the instantaneous center of rotation, one rigid link rotates instantaneously relative to another for the configuration of mechanism considered
B.	The two rigid links have no linear velocities relative to each other at the instantaneous center
C.	The two rigid links which have no linear velocity relative to each other at this center have the same linear velocity to the third rigid link
D.	The double center can be denoted either by O2 or O12, but proper selection should be made
Answer» E.

Discussion

Explore topic-wise MCQs in Mechanical Engineering.

When the two elements of a pair have __________ when in motion, it is said to a lower pair.

Open pairs are those which have

A body is said to be under forced vibrations, when

V-belts are usually used for

Scotch yoke mechanism is used to generate

The frictional torque transmitted in a truncated conical pivot bearing, considering uniform wear, is

The frictional torque transmitted in a conical pivot bearing, considering uniform wear, is

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

The condition for correct steering of a Davis steering gear is (where α = Angle of inclination of the links to the vertical)

There are six gears A, B, C, D, E and F in a compound train. The numbers of teeth in the gears are 20, 60, 30, 80, 25 and 75 respectively. The ratio of angular speeds of the driven (F) to the driver (A) of the drive is

The C.G. of a link in any mechanism would experience

The lead screw of a lathe with nut forms a

A point B on a rigid link AB moves with respect to A with angular velocity ω rad/s. The total acceleration of B with respect to A will be equal to

A mechanism consisting of four links is called a __________ mechanism.

A rotary internal combustion engine has __________ cylinders.

When two pulleys are connected by means of a cross belt drive, then both the pulleys will rotate in _________ directions.

In a rigid link OA, velocity of 'A' w.r.t. 'O' will be

Power of a governor is the

Effort of a governor is the

When the addenda on pinion and wheel is such that the path of approach and path of recess are half of their maximum possible values, then the length of the path of contact is given by (where r = Pitch circle radius of pinion, R = Pitch circle radius of wheel, and φ = Pressure angle)

The dedendum circle diameter is equal to (where, φ = Pressure angle)

The maximum efficiency of spiral gears is (where θ = Shaft angle, and φ = Friction angle)

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

The instantaneous center of a rigid thin disc rolling on a plane rigid surface is located at

In a shaper mechanism, the Coriolis component of acceleration will

The Coriolis component of acceleration acts

In a four bar chain or quadric cycle chain

The frictional torque transmitted in a flat pivot bearing, assuming uniform wear, is(Where μ = Coefficient of friction, W=Load over the bearing, R=Radius of bearing)

For an involute gear, the ratio of base circle radius and pitch circle radius is equal to

In vibration isolation system, the transmissibility will be equal to unity, for all values of damping factor, if ω/ωn is

The example of successfully constrained motion is a

The example of completely constrained motion is a

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

A body having moment of inertia o:m2 is rotating at 210 RPM and r with another body at rest having I 40 kg m2. The resultant speed after ing will be

A torsional system with discs of moment of inertia I₁ and I₂ as shown in the below figure, is gear driven such that the ratio of speed of shaft B to shaft A is 'G'. Neglecting the inertia of gears, the equivalent inertia of disc on shaft B at the speed of shaft A is equal to

In a pantograph, all the pairs are

The mechanism in which two are turning pairs and two are sliding pairs, is called a

The main disadvantage of the sliding pair is that it is

Cylindrical cams can be classified as

A circle passing through the pitch point with its center at the center of cam axis is known as

The frequency of damped vibrations with viscous damping is ________ the frequency of undamped vibrations.

A rigid body, under the action of external forces, can be replaced by two masses placed at a fixed distance apart. The two masses form an equivalent dynamical system, if

If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then energy stored in the latter at the same speed will be

Frequency of vibrations is usually expressed in

A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by (where μ = tan φ = Coefficient of friction between the plane and the body)

A slider crank chain consists of following numbers of turning and sliding pairs

Cross head and guides form a

For dynamic balancing of a shaft

In a Hartnell governor, the lift of the sleeve is given by (where r₁ and r₂ = Max. and min. radii of rotation, x = Length of ball arm of the lever, and y = Length of sleeve arm of the lever)

Which is the false statement about the properties of instantaneous center?