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
Correct Answer :
C. kG²/h
Related Questions
In a simple harmonic motion, the velocity vector with respect to displacement vector
Is in phase
Leads by 90°
Leads by 180°
Lags by 90°
The centrifugal tension in belts
Increases power transmitted
Decreases power transmitted
Have no effect on power transmitted
Increases power transmitted upto a certain speed and then decreases
The acceleration of a flat-faced follower when it has contact with the flank of a circular arc cam, is given by
ω² R cosθ
ω² (R - r₁) cosθ
ω² (R - r₁) sinθ
ω² r₁ sinθ
The unbalanced primary forces in a reciprocating engine are
Balanced completely
Balanced partially
Balanced by secondary forces
Not balanced
The total number of instantaneous centres for a mechanism consisting of n links are
n/2
n
n - 1
n(n - 1)/2
The motion between a pair when limited to a definite direction, irrespective of the direction of force applied, is known as
Completely constrained motion
Incompletely constrained motion
Successfully constrained motion
None of these
Pitch point of a cam is
A point on the pitch curve having minimum pressure angle
A point on the pitch curve having maximum pressure angle
Any point on the pitch curve
Any point on the pitch circle
The cam follower generally used in automobile engines is
Knife edge follower
Flat faced follower
Spherical faced follower
Roller follower
The Ackermann steering mechanism is preferred to the Davis type in automobiles because
The former is mathematically accurate
The former is having turning pair
The former is most economical
The former is most rigid
In a four stroke I.C. engine, the turning moment during the compression stroke is
Positive throughout
Negative throughout
Positive during major portion of the stroke
Negative during major portion of the stroke
The example of lower pair is
Shaft revolving in a bearing
Straight line motion mechanisms
Automobile steering gear
All of the above
In a mechanism, usually one link is fixed. If the fixed link is changed in a kinematic chain, then relative motion of other links
Will remain same
Will change
Could change or remain unaltered depending on which link is fixed
Will not occur
The D-slide valve is also known as
Inside admission valve
Outside admission valve
Piston slide valve
None of these
The static friction
Bears a constant ratio to the normal reaction between the two surfaces
Is independent of the area of contact, between the two surfaces
Always acts in a direction, opposite to that in which the body tends to move
All of the above
What is the number of instantaneous centres for an eight link mechanism?
15
28
30
8
The pressure angle of a cam is the angle between the direction of the follower motion and a normal to the
Pitch circle
Base circle
Pitch curve
Prime circle
The critical speed of a shaft depends upon its
Mass
Stiffness
Mass and stiffness
Stiffness and eccentricity
In railway axle boxes, the bearing used is
Deep groove ball bearing
Double row self aligning ball bearing
Double row spherical roller bearing
Cylindrical roller bearing
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
A kinematic chain requires at least
2 links and 3 turning pairs
3 links and 4 turning pairs
4 links and 4 turning pairs
5 links and 4 turning pairs
The Kutzbach criterion for determining the number of degrees of freedom (n) is (where l = number of links, j = number of joints and h = number of higher pairs)
n = 3(l - 1) - 2j - h
n = 2(l - 1) -2j - h
n = 3(l - 1) - 3j - h
n = 2(l - 1) - 3j - h
Which of the following is false statement in respect of differences between machine and structure?
Machines transmit mechanical work, whereas structures transmit forces
In machines, relative motion exists between its members, whereas same does not exist in case of structures
Machines modify movement and work, whereas structures modify forces
Efficiency of machines as well as structures is below 100%
The method of obtaining different mechanisms by fixing in turn different links in a kinematic chain, is known as
Structure
Machine
Inversion
Compound mechanism
Oldhams coupling is an inversion of the kinematic chain used in
Whitworth quick return mechanism
Elliptical trammels
Rotary engine
Universal joint
The product of the diametral pitch and circular pitch is equal to
1
1/π
π
2 π
If the opposite links of a four bar linkage are equal, the links will always form a
Triangle
Rectangle
Parallelogram
Pentagon
The Hooke's joint consists of:
Two forks
One fork
Three forks
Four forks
The relation between the controlling force (Fc) and radius of rotation (r) for a stable spring controlled governor is
Fc = ar + b
Fc = ar - b
Fc = ar
Fc = a/r + b
The maximum fluctuation of energy is the
Difference between the maximum and minimum energies
Sum of the maximum and minimum energies
Variations of energy above and below the mean resisting torque line
Ratio of the mean resisting torque to the workdone per cycle
A point on a connecting link (excluding end points) of a double slider crank mechanism traces a
Straight line path
Hyperbolic path
Parabolic path
Elliptical path