The critical speed of a shaft with a disc supported in between is equal to the natural frequency of the system in
Transverse vibrations
Torsional vibrations
Longitudinal vibrations
All of these
Correct Answer :
A. Transverse vibrations
Related Questions
The example of completely constrained motion is a
Motion of a piston in the cylinder of a steam engine
Motion of a square bar in a square hole
Motion of a shaft with collars at each end in a circular hole
All of the above
Which of the following is an open pair?
Ball and socket joint
Journal bearing
Lead screw and nut
Cam and follower
Crowning on pulleys helps
In increasing velocity ratio
In decreasing the slip of the belt
For automatic adjustment of belt position so that belt runs centrally
Increase belt and pulley life
The acceleration of the reciprocating roller follower when it has contact with the straight flanks of the tangent cam, is given by
ω². (r₁ r₂). (1 - cos² θ)
ω². (r₁ + r₂). (1 + cos² θ)
ω². (r₁ + r₂). [(2 - cos² θ)/cos³ θ]
ω². (r₁ - r₂). (1 - sin² θ)
The frictional torque transmitted by a disc or plate clutch is same as that of
Flat pivot bearing
Flat collar bearing
Conical pivot bearing
Truncated conical pivot bearing
The maximum velocity of a particle moving with simple harmonic motion is
ω
ωr
ω²r
ω/r
The type of coupling used to join two shafts whose axes are neither in same straight line nor parallel, but intersect is
Flexible coupling
Universal coupling
Chain coupling
Oldham's coupling
The example of lower pair is
Shaft revolving in a bearing
Straight line motion mechanisms
Automobile steering gear
All of the above
The number of links and instantaneous centers in a reciprocating engine mechanism are
4, 4
4, 5
5, 4
4, 6
The factor which affects the critical speed of a shaft is
Diameter of disc
Span of shaft
Eccentricity
All of these
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
Which of the following is a turning pair?
Piston and cylinder of a reciprocating steam engine
Shaft with collars at both ends fitted into a circular hole
Lead screw of a lathe with nut
Ball and a socket joint
A fixed gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by an arm. The number of turns made by the smaller gear for one revolution of arm about the centre of bigger gear is
2
4
3
None of the above
When the sleeve of a Porter governor moves upwards, the governor speed
Increases
Decreases
Remain unaffected
First increases and then decreases
When the primary direct crank of a reciprocating engine makes an angle of θ with the line of stroke, then the secondary direct crank will make an angle of _________ with the line of stroke.
θ/2
θ
2θ
4θ
In a cam drive with uniform velocity follower, the sharp corners of the displacement diagram are rounded off at the beginning and at the end of each stroke. This is done
Because of difficulty in manufacturing cam profile
Because of loose contact of follower with cam surface
In order to have acceleration in beginning and retardation at the end of stroke within the finite limits
Because the uniform velocity motion is a partial parabolic motion
If the pressure angle is __________, a reciprocating follower will jam in its bearings.
Small
Too small
Large
Too large
Which of the following statement is correct for involute gears?
The interference is inherently absent.
The variation in centre distance of shafts increases radial force.
A convex flank is always in contact with concave flank.
The pressure angle is constant throughout the teeth engagement.
Ball and a Socket forms a
Turning pair
Rolling pair
Screw pair
Spherical pair
If the number of links in a mechanism is equal to l, then the numbers of possible inversions are equal to
l - 2
l - 1
l
l + 1
A circular bar moving in a round hole is an example of
Incompletely constrained motion
Partially constrained motion
Completely constrained motion
Successfully constrained motion
The balancing of a rigid rotor can be achieved by appropriately placing balancing masses in
A single plane
Two planes
Three planes
Four planes
In a simple train of wheels, the velocity ratio __________ the intermediate wheels.
Depends upon
Is independent of
Either A or B
None of these
The angle of inclination of the plane, at which the body begins to move down the plane is called
Angle of friction
Angle of repose
Angle of projection
None of these
The height of a Watt's governor is
Directly proportional to speed
Directly proportional to (speed)²
Inversely proportional to speed
Inversely proportional to (speed)²
The displacement of the D-slide valve is __________ the steam lap by a distance known as lead of the valve.
Greater than
Less than
Equal to
None of these
Which is the false statement about the properties of instantaneous centre?
At the instantaneous center of rotation, one rigid link rotates instantaneously relative to another for the configuration of mechanism considered
The two rigid links have no linear velocities relative to each other at the instantaneous centre
The two rigid links which have no linear velocity relative to each other at this center have the same linear velocity to the third rigid link
The double centre can be denoted either by O2 or O12, but proper selection should be made
Throw of a cam is the maximum distance of the follower from
Base circle
Pitch circle
Root circle
Prime circle
When a body is subjected to transverse vibrations, the stress induced in a body will be
Shear stress
Bending stress
Tensile stress
Compressive stress
Angle of action of cam is defined as the angle
Of rotation of the cam for a definite displacement of the follower
Through which the cam rotates during the period in which the follower remains in the highest position
Moved by the cam from the instant the follower begins to rise, till it reaches its highest position
Moved by the cam from beginning of ascent to the termination of descent