Flexible coupling is used because
It is easy to disassemble
It is easy to engage and disengage
It transmits shocks gradually
It prevents shock transmission and eliminates stress reversals
Correct Answer :
D. It prevents shock transmission and eliminates stress reversals
Related Questions
In order to balance the reciprocating masses,
Primary forces and couples must be balanced
Secondary forces and couples must be balanced
Both (A) and (B)
None of these
Coriolis component acts
Perpendicular to sliding surfaces
Along sliding surfaces
Somewhere in between above two
None of the above
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
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
1/24
1/8
4/15
12
A mass of 1 kg is attached to the end of a spring with a stiffness of 0.7 N/mm. The critical damping coefficient of this system is
1.4 N-s/m
18.52 N-s/m
52.92 N-s/m
529.2 N-s/m
The example of rolling pair is
Bolt and nut
Lead screw of a lathe
Ball and socket joint
Ball bearing and roller bearing
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?
All points of the disc have the same velocity
The centre of the disc has zero acceleration
The centre of the disc has centrifugal acceleration
The point on the disc making contact with the plane surface has zero acceleration
The example of lower pair is
Shaft revolving in a bearing
Straight line motion mechanisms
Automobile steering gear
All of the above
When the particles of a body moves perpendicular to its axis, then the body is said to have
Longitudinal vibration
Transverse vibration
Torsional vibration
None of these
In a gear having involute teeth, the normal to the involute is a tangent to the
Pitch circle
Base circle
Addendum circle
Dedendum circle
In a four bar chain or quadric cycle chain
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
An exact straight line motion mechanism is a
Scott-Russell's mechanism
Hart's mechanism
Peaucellier's mechanism
All of these
The centre of percussion is below the centre of gravity of the body and is at a distance equal to
h/kG
h²/kG
kG²/h
h × kG
A Porter governor is a
Pendulum type governor
Dead weight governor
Spring loaded governor
Inertia governor
The radial distance of a tooth from the pitch circle to the bottom of the tooth is called
Dedendum
Addendum
Clearance
Working depth
The periodic time is given by (where ω = Angular velocity of the particle in rad/s)
ω/2π
2π/ω
ω × 2π
π/ω
The mechanism forms a structure, when the number of degrees of freedom (n) is equal to
0
1
2
-1
If D₁ and D₂ be the diameters of driver and driven pulleys, then belt speed is proportional to
D₁/D₂
D₂/D₁
D₁.D₂
D₁
The efficiency of a screw jack is maximum, when (where α = Helix angle, and φ = Angle of friction)
α = 45° + φ/2
α = 45° - φ/2
α = 90° + φ
α = 90° - φ
When the pitching of a ship is upward, the effect of gyroscopic couple acting on it will be
To move the ship towards starboard
To move the ship towards port side
To raise the bow and lower the stern
To raise the stern and lower the bow
For the brake to be self locking, the force P at C shown in the below figure, should 
Be zero
Act in upward direction
Act in downward direction
None of these
Kinematic pairs are those which have
Two elements held together mechanically
Two elements having relative motion
Two elements having Coriolis component
Minimum of two instantaneous centres
Shaft revolving in a bearing is the following type of pair
Lower pair
Higher pair
Spherical pair
Cylindrical pair
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
Lower pairs are those which have
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
The method of obtaining different mechanisms by fixing in turn different links in a kinematic chain, is known as
Structure
Machine
Inversion
Compound mechanism
When the sleeve of a Porter governor moves upwards, the governor speed
Increases
Decreases
Remain unaffected
First increases and then decreases
In a hydrodynamic journal bearing, there is
A very thin film of lubricant between the journal and the bearing such that there is contact between the journal and the bearing
A thick film of lubricant between the journal and the bearing
No lubricant between the journal and the bearing
A forced lubricant between the journal and the bearing
Under logarithmic decrement, the amplitude of successive vibrations are
Constant
In arithmetic progression
In geometric progression
In logarithmic progression
In multi V-belt transmission, if one of the belt is broken, we have to change the
Broken belt
Broken belt and its adjacent belts
All the belts
There is no need of changing any one as remaining belts can take care of transmission of load