When the speed of the engine fluctuates continuously above and below the mean speed, the governor is said to be
Stable
Unstable
Isochronous
Hunt
Correct Answer :
D. Hunt
Related Questions
The Bifilar suspension method is used to determine
Natural frequency of vibration
Position of balancing weights
Moment of inertia
Centripetal acceleration
Which of the following property of the instantaneous centre is correct?
A rigid link rotates instantaneously relative to another link at the instantaneous centre for the configuration of the mechanism considered.
The two rigid links have no linear velocity relative to each other at the instantaneous centre.
The velocity of the instantaneous centre relative to any third rigid link is same whether the instantaneous centre is regarded as a point on the first rigid link or on the second rigid link.
All of the above
The swaying couple is maximum or minimum when the angle of inclination of the crank to the line of stroke (θ) is equal to
90° and 180°
45° and 225°
180° and 270°
270° and 360°
In a ball bearing, ball and bearing forms a
Turning pair
Rolling pair
Screw pair
Spherical pair
The motion of a shaft in a circular hole is an example of
Completely constrained motion
Incompletely constrained motion
Successfully constrained motion
None of these
In a shaper mechanism, the Coriolis component of acceleration will
Not exist
Exist
Depend on position of crank
None of the above
Efficiency of a screw jack is given by
tan (α + φ)/tanα
tanα/tan (α +φ)
tan (α - φ)/tanα
tanα/tan (α - φ)
Balancing of rotating and reciprocating parts of an engine is necessary when it runs at
Slow speed
Moderate speed
Highs peed
Any one of these
The velocity of the reciprocating roller follower when it has contact with the straight flanks of the tangent cam, is given by (where ω = Angular velocity of the cam shaft)
ω (r₁ r₂) sinθ
ω (r₁ + r₂) sinθ sec2θ
ω (r₁ r₂) cosθ
ω (r₁ + r₂) cosθ cosec2θ
The condition for correct steering of a Davis steering gear is (where α = Angle of inclination of the links to the vertical)
sinα = b/c
cosα = c/b
tanα = c/2b
cotα = c/2b
Whirling speed of the shaft is the speed at which
Shaft tends to vibrate in longitudinal direction
Torsional vibrations occur
Shaft tends to vibrate vigorously in transverse direction
Combination of transverse and longitudinal vibration occurs
The mechanism in which two are turning pairs and two are sliding pairs, is called a
Double slider crank chain
Elliptical trammel
Scotch yoke mechanism
All of these
The C.G. of a link in any mechanism would experience
No acceleration
Linear acceleration
Angular acceleration
Both angular and linear accelerations
The working depth of a gear is the radial distance from the
Pitch circle to the bottom of a tooth
Pitch circle to the top of a tooth
Top of a tooth to the bottom of a tooth
Addendum circle to the clearance circle
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
To raise the bow and stern
To lower the bow and stern
To raise the bow and lower the stern
To raise the stern and lower the bow
In order to double the period of a simple pendulum, the length of the string should be
Halved
Doubled
Quadrupled
None of these
Angular acceleration of a link can be determined by dividing the
Centripetal component of acceleration with length of link
Tangential component of acceleration with length of link
Resultant acceleration with length of link
All of the above
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.
Same
Two times
Four times
None of these
The method of direct and reverse cranks is used in engines for
The control of speed fluctuations
Balancing of forces and couples
Kinematic analysis
Vibration analysis
A single degree of freedom system is given by, m × (d²x/dt²) + c × (dx/dt) + sx = F.cosω.t with usual notations. It represents
Free vibration with damping
Free vibration without damping
Forced vibration with damping
Forced vibration without damping
Ackermann steering gear consists of
Sliding pairs
Turning pairs
Rolling pairs
Higher pairs
The tractive force is maximum or minimum when the angle of inclination of crank with the line of stroke (θ) is equal to
0° and 90°
90° and 180°
135° and 315°
270° and 360°
The cam follower generally used in aircraft engines is
Knife edge follower
Flat faced follower
Spherical faced follower
Roller follower
In S.H.M., the velocity vector w.r.t. displacement vector
Leads by 90°
Lags by 90°
Leads by 180°
Are in phase
The radial distance from the top of a tooth to the bottom of a tooth in a meshing gear, is called
Dedendum
Addendum
Clearance
Working depth
In a steam engine, the distance by which the outer edge of the Dslide valve overlaps the steam port is called
Lead
Steam lap
Exhaust lap
None of these
The instantaneous centre of a rigid thin disc rolling on a plane rigid surface is located at
The centre of the disc
The point of contact
An infinite distance on the plane surface
The point on the circumference situated vertically opposite to the contact point
Under logarithmic decrement, the amplitude of successive vibrations are
Constant
In arithmetic progression
In geometric progression
In logarithmic progression
Pitch point on a cam is
Any point on pitch curve
The point on cam pitch curve having the maximum pressure angle
Any point on pitch circle
The point on cam pitch curve having the minimum pressure angle
The lower pairs are __________ pairs.
Self-closed
Force-closed
Friction closed
None of these