The velocity of any point in mechanism relative to any other point on the mechanism on velocity polygon is represented by the line
Joining the corresponding points
Perpendicular to line as per (A)
Not possible to determine with these data
At 45° to line as per (A)
Correct Answer :
A. Joining the corresponding points
Related Questions
Hammer blow
Is the maximum horizontal unbalanced force caused by the mass provided to balance the reciprocating masses.
Is the maximum vertical unbalanced force caused by the mass added to balance the reciprocating masses
Varies as the square root of the speed
Varies inversely with the square of the speed
TJIE horse power transmitted by a belt is dependent upon
Tension on tight side of belt
Tension on slack side of belt
Radius of pulley
All of the above
Whitworth quick return mechanism is obtained by inversion of
Slider crank mechanism
Kinematic chain
Five link mechanism
Roller cam mechanism
The danger of breakage and vibration is maximum
Below the critical speed
Near the critical speed
Above the critical speed
None of these
When the axes of the first and last wheels are coaxial, then the train is known as
Simple train of wheels
Compound train of wheels
Reverted gear train
Epicyclic gear train
The product of the diametral pitch and circular pitch is equal to
1
1/π
π
2 π
Power of a governor is the
Mean force exerted at the sleeve for a given percentage change of speed
Workdone at the sleeve for maximum equilibrium speed
Mean force exerted at the sleeve for maximum equilibrium speed
None of the above
The Klein's method of construction for reciprocating engine mechanism
Is a simplified version of instantaneous centre method
Utilises a quadrilateral similar to the diagram of mechanism for reciprocating engine
Enables determination of coriolis component
Is based on the acceleration diagram
In a system subjected to damped forced vibrations, the ratio of maximum displacement to the static deflection is known as
Critical damping ratio
Damping factor
Logarithmic decrement
Magnification factor
Oldhams coupling is an inversion of the kinematic chain used in
Whitworth quick return mechanism
Elliptical trammels
Rotary engine
Universal joint
When a point moves along a straight line, its acceleration will have
Radial component only
Tangential component only
Coriolis component only
Radial and tangential components both
The number of links in pantograph mechanism is equal to
2
3
4
5
It is required to connect two parallel shafts, the distance between whose axes is small and variable. The shafts are coupled by
Universal joint
Knuckle joint
Oldham's coupling
Flexible coupling
Coriolis component acts
Perpendicular to sliding surfaces
Along sliding surfaces
Somewhere in between above two
None of the above
Open 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 number of centers in a crank driven slider crank mechanism is
0
2
4
6
For fluctuating loads, well suited bearing is
Ball bearing
Roller bearing
Needle roller bearing
Thrust bearing
When the nature of contact between the elements of a pair is such that one element can turn about the other by screw threads, the pair is known as a
Screw pair
Spherical pair
Turning pair
Sliding pair
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.
All of the above
The coriolis component of acceleration depends upon
Velocity of slider
Angular velocity of the link
Both (A) and (B)
None of these
The sensitiveness of the governor __________ as the speed range decreases.
Remains unaffected
Decreases
Increases
None of these
Scotch yoke mechanism is used to generate
Sine functions
Square roots
Logarithms
Inversions
Sensitiveness of the governor is defined as the ratio of the
Mean speed to the maximum equilibrium speed
Mean speed to the minimum equilibrium speed
Difference of the maximum and minimum equilibrium speeds to the mean speed
Sum of the maximum and minimum equilibrium speeds to the mean speed
Which of the following is an example of a higher pair?
Toothed gearing
Belt and rope drive
Ball and roller bearing
All of these
A foot step bearing and rotor of a vertical turbine form examples of
Incompletely constrained motion
Partially constrained motion
Completely constrained motion
Successfully constrained motion
What is the number of instantaneous centres for an eight link mechanism?
15
28
30
8
When the crank is at the outer dead centre, in a reciprocating steam engine, then the acceleration of the piston will be
ω² r {(n + 1)/n}
ω² r {(n - 1)/n}
ω² r {n/(n + 1)}
ω² r {n/(n - 1)}
The displacement of the reciprocating roller follower, when it has contact with the straight flanks of the tangent cam, is given by (where r₁ = Minimum radius of the cam, r₂ = Radius of the roller follower, and θ = Angle turned by the cam from the beginning of the follower displacement)
(r₁ - r₂) (1 - cosθ)
(r₁ + r₂) (1 + cosθ)
(r₁ - r₂) [(1 - cosθ)/cos θ]
(r₁ + r₂) [(1 - cosθ)/cos θ]
The coriolis component of acceleration exists whenever a point moves along a path that has
Linear displacement
Rotational motion
Gravitational acceleration
Tangential acceleration
The essential condition of placing the two masses, so that the system becomes dynamically equivalent, is (where l₁ and l₂ = Distance of two masses from the centre of gravity of the body, and kG = Radius of gyration of the body)
l₁ = kG
l₂ = kG
l₁l₂ = kG
l₁l₂ = kG²