4791 + Mcqs in Mechanical Engineering Page 79 McqOptions

3901.	When two links are connected by a pin joint, their instantaneous centre lies
A.	on their point of contact
B.	at the centre of curvature
C.	at the centre of circle
D.	at the pin joint
Answer» E.

Discussion

3902.	The natural frequency of free torsional vibrations of a shaft is equal to (where q = Torsional stiffness of the shaft, and I = Mass moment of inertia of the disc attached at the end of a shaft)
A.	<img src="/_files/images/mechanical-engineering/theory-of-machines/518-508-1.png">
B.	2
C.	<span class="root"><i>qI</i></span>
D.	<img src="/_files/images/mechanical-engineering/theory-of-machines/518-508-2.png">
E.	<img src="/_files/images/mechanical-engineering/theory-of-machines/518-508-3.png">
Answer» D. <img src="/_files/images/mechanical-engineering/theory-of-machines/518-508-2.png">

Discussion

3903.	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

3904.	In a Hartnell governor, if a spring of greater stiffness is used, then the governor will be
A.	less sensitive
B.	more sensitive
C.	unaffected of sensitivity
D.	isochronous
Answer» B. more sensitive

Discussion

3905.	The included angle for the V-belt is usually
A.	10 to 20
B.	20 to 30
C.	30 to 40
D.	60 to 80
Answer» D. 60 to 80

Discussion

3906.	Which of the following is used to control the speed variations of the engine caused by the fluctuations of the engine turning moment?
A.	D-slide valve
B.	Governor
C.	Flywheel
D.	Meyer's expansion valve
Answer» D. Meyer's expansion valve

Discussion

3907.	The ratio of driving tensions for rope drive is same as that of V-belt drive.
A.	Yes
B.	No
Answer» B. No

Discussion

3908.	A Hartnell governor is a
A.	dead weight governor
B.	pendulum type governor
C.	spring loaded governor
D.	inertia governor
Answer» D. inertia governor

Discussion

3909.	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

3910.	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

3911.	Most of the engines, generally, do not require balancing of secondary forces and couples.
A.	Right
B.	Wrong
Answer» B. Wrong

Discussion

3912.	A spring controlled governor is found unstable. It can be made stable by
A.	increasing the spring stiffness
B.	decreasing the spring stiffness
C.	increasing the ball mass
D.	decreasing the ball mass
Answer» C. increasing the ball mass

Discussion

3913.	In order to have a good grip on the pulley, the V-belt should touch the bottom of the groove in the pulley.
A.	True
B.	False
Answer» C.

Discussion

3914.	In order to double the period of a simple pendulum, the length of the string should be
A.	halved
B.	doubled
C.	quadrupled
D.	none of these
Answer» D. none of these

Discussion

3915.	The displacement of the D-slide valve is __________ the steam lap by a distance known as lead of the valve.
A.	greater than
B.	less than
Answer» B. less than

Discussion

3916.	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

3917.	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

3918.	A spring controlled governor is said to be unstable, if the relation between the controlling force (Fc) and radius of rotation (r) is Fc = ar.
A.	Agree
B.	Disagree
Answer» C.

Discussion

3919.	The rotor of a ship rotates in clockwise direction when viewed from stern and the ship takes a left turn. The effect of gyroscopic couple acting on it will be
A.	to raise the bow and stern
B.	to lower the bow and stern
C.	to raise the bow and lower the stern
D.	to raise the stern and lower the bow
Answer» D. to raise the stern and lower the bow

Discussion

3920.	The swaying couple is due to the
A.	primary unbalanced force
B.	secondary unbalanced force
C.	two cylinders of locomotive
D.	partial balancing
Answer» B. secondary unbalanced force

Discussion

3921.	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

3922.	In forced vibrations, the magnitude of damping force at resonance is equal to the impressed force.
A.	Correct
B.	Incorrect
Answer» B. Incorrect

Discussion

3923.	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

3924.	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

3925.	Two pulleys of radii r1 and r2 and at distance x apart are connected by means of a cross belt drive. The length of the belt is
A.	<img src="/_files/images/mechanical-engineering/theory-of-machines/488-200-1.png">
B.	<img src="/_files/images/mechanical-engineering/theory-of-machines/488-200-2.png">
C.	<img src="/_files/images/mechanical-engineering/theory-of-machines/488-200-3.png">
D.	<img src="/_files/images/mechanical-engineering/theory-of-machines/488-200-4.png">
Answer» B. <img src="/_files/images/mechanical-engineering/theory-of-machines/488-200-2.png">

Discussion

3926.	In vibration isolation system, if / n > 2, then for all values of damping factor, the trans-missibility (i.e. the ratio of the force transmitted to the force applied) will be less than unity.
A.	True
B.	False
Answer» B. False

Discussion

3927.	For the brake to be self locking, the force P at C shown in the below figure, should
A.	be zero
B.	act in upward direction
C.	act in downward direction
D.	none of these
Answer» B. act in upward direction

Discussion

3928.	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

3929.	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

3930.	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

3931.	When the elements of a pair are kept in contact by the action of external forces, the pair is said to be a
A.	lower pair
B.	higher pair
C.	self-closed pair
D.	force-closed pair
Answer» E.

Discussion

3932.	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

Discussion

3933.	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

3934.	A shaft of mass (mc) and stiffness (s) is fixed at one end and carries a mass (m) at the other end. The natural frequency of its longitudinal vibration is equal to
A.	<img src="/_files/images/mechanical-engineering/theory-of-machines/514-465-1.png">
B.	<img src="/_files/images/mechanical-engineering/theory-of-machines/514-465-2.png">
C.	<img src="/_files/images/mechanical-engineering/theory-of-machines/514-465-3.png">
D.	<img src="/_files/images/mechanical-engineering/theory-of-machines/514-465-4.png">
Answer» E.

Discussion

3935.	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

3936.	A body in motion will be subjected to coriolis acceleration when that body is
A.	in plane rotation with variable velocity
B.	in plane translation with variable velocity
C.	in plane motion which is a resultant of plane translation and rotation
D.	restrained to rotate while sliding over another body
Answer» E.

Discussion

3937.	The rolling of a complete ship side-ways is known as pitching of a ship.
A.	True
B.	False
Answer» C.

Discussion

3938.	The arrangement is called bevel gearing, when two __________ are connected by gears.
A.	intersecting and coplaner shafts
B.	non-intersecting and non-coplaner shafts
C.	parallel and coplaner shafts
D.	parallel and non-coplaner shafts
Answer» B. non-intersecting and non-coplaner shafts

Discussion

3939.	The controlling force diagram for a spring controlled governor is a curve passing through the origin.
A.	Yes
B.	No
Answer» C.

Discussion

3940.	The static balancing is satisfactory for low speed rotors but with increasing speeds, dynamic balancing becomes necessary. This is because, the
A.	unbalanced couples are caused only at higher speeds
B.	unbalanced forces are not dangerous at higher speeds
C.	effects of unbalances are proportional to the square of the speed
D.	effects of unbalances are directly proportional to the speed
Answer» D. effects of unbalances are directly proportional to the speed

Discussion

3941.	The maximum fluctuation of speed is the
A.	difference of minimum fluctuation of speed and the mean speed
B.	difference of the maximum and minimum speeds
C.	sum of maximum and minimum speeds
D.	variations of speed above and below the mean resisting torque line
Answer» C. sum of maximum and minimum speeds

Discussion

3942.	When the sleeve of a Porter governor moves downwards, the governor speed
A.	increases
B.	decreases
C.	remains unaffected
D.	first increases and then decreases
Answer» C. remains unaffected

Discussion

3943.	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

3944.	The natural frequency of free transverse vibrations of a shaft fixed at both ends and carrying a uniformly distributed load is 0.571/ S , where S 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

3945.	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
Answer» C. zero

Discussion

3946.	The ratio of the number of teeth to the pitch circle diameter in millimetres, is called
A.	circular pitch
B.	diametral pitch
C.	module
D.	none of these
Answer» C. module

Discussion

3947.	In a steam engine, the distance by which the outer edge of the D-slide valve overlaps the steam port is called
A.	lead
B.	steam lap
C.	exhaust lap
D.	none of these
Answer» C. exhaust lap

Discussion

3948.	The ratio of the pitch circle diameter in millimetres to the number of teeth, is called circular pitch.
A.	Yes
B.	No
Answer» C.

Discussion

3949.	The rotating shafts tend to vibrate violently at whirling speeds because
A.	the system is unbalanced
B.	bearing centre line coincides with the axis
C.	the shafts are rotating at very high speeds
D.	resonance is caused due to the heavy mass of the rotor
Answer» E.

Discussion

3950.	Which of the following is an inversion of a double slider crank chain?
A.	Oldham's coupling
B.	Elliptical trammel
C.	Scotch yoke mechanism
D.	all of these
Answer» E.

Discussion

Explore topic-wise MCQs in Engineering.

When two links are connected by a pin joint, their instantaneous centre lies

The natural frequency of free torsional vibrations of a shaft is equal to (where q = Torsional stiffness of the shaft, and I = Mass moment of inertia of the disc attached at the end of a shaft)

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

In a Hartnell governor, if a spring of greater stiffness is used, then the governor will be

The included angle for the V-belt is usually

Which of the following is used to control the speed variations of the engine caused by the fluctuations of the engine turning moment?

The ratio of driving tensions for rope drive is same as that of V-belt drive.

A Hartnell governor is a

Frequency of vibrations is usually expressed in

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

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

A spring controlled governor is found unstable. It can be made stable by

In order to have a good grip on the pulley, the V-belt should touch the bottom of the groove in the pulley.

In order to double the period of a simple pendulum, the length of the string should be

The displacement of the D-slide valve is __________ the steam lap by a distance known as lead of the valve.

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

The lead screw of a lathe with nut forms a

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

The rotor of a ship rotates in clockwise direction when viewed from stern and the ship takes a left turn. The effect of gyroscopic couple acting on it will be

The swaying couple is due to the

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

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

Two pulleys of radii r1 and r2 and at distance x apart are connected by means of a cross belt drive. The length of the belt is

In vibration isolation system, if / n &gt; 2, then for all values of damping factor, the trans-missibility (i.e. the ratio of the force transmitted to the force applied) will be less than unity.

For the brake to be self locking, the force P at C shown in the below figure, should

In a four bar chain or quadric cycle chain

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.

When the elements of a pair are kept in contact by the action of external forces, the pair is said to be a

The centrifugal tension in belts

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

A shaft of mass (mc) and stiffness (s) is fixed at one end and carries a mass (m) at the other end. The natural frequency of its longitudinal vibration is equal to

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

A body in motion will be subjected to coriolis acceleration when that body is

The rolling of a complete ship side-ways is known as pitching of a ship.

The arrangement is called bevel gearing, when two __________ are connected by gears.

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

The static balancing is satisfactory for low speed rotors but with increasing speeds, dynamic balancing becomes necessary. This is because, the

The maximum fluctuation of speed is the

When the sleeve of a Porter governor moves downwards, the governor speed

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/ S , where S is the static deflection of a shaft fixed at both ends and carrying a uniformly distributed load.

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

The ratio of the number of teeth to the pitch circle diameter in millimetres, is called

In a steam engine, the distance by which the outer edge of the D-slide valve overlaps the steam port is called

The ratio of the pitch circle diameter in millimetres to the number of teeth, is called circular pitch.

The rotating shafts tend to vibrate violently at whirling speeds because

Which of the following is an inversion of a double slider crank chain?

In vibration isolation system, if / n > 2, then for all values of damping factor, the trans-missibility (i.e. the ratio of the force transmitted to the force applied) will be less than unity.