A rotor which is balanced statically but not dynamically is supported on two bearings L apart and at high speed of the rotor, reaction on the left bearing is R. The right side of the bearing is shifted to a new position 2L apart from the left bearing. At the same rotor speed, dynamic reaction on the left bearing in the new arrangement will
Remain same as before
Become equal to 2R
Become equal to R/2
Become equal to R/4
Correct Answer :
A. Remain same as before
Related Questions
The frictional torque transmitted in a flat pivot bearing with assumption of uniform pressure is _________ as compared to uniform wear.
Less
More
Same
None of these
Minimum number of teeth for involute rack and pinion arrangement for pressure angle of 20° is
18
20
30
34
The type of pair formed by two elements which are so connected that one is constrained to turn or revolve about a fixed axis of another element is known as
Turning pair
Rolling pair
Sliding pair
Spherical pair
In a steam engine, the earlier cut-off with a simple slide valve may be obtained by increasing the steam lap and the angle of advance of the eccentric but keeping constant the travel and lead of the valve, this method will
Cause withdrawing or throttling of steam
Reduce length of effective stroke of piston
Reduce maximum opening of port to steam
All of these
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
A cam with a roller follower would constitute following type of pair
Lower pair
Higher pair
Open pair
Close pair
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
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
The method of obtaining different mechanisms by fixing in turn different links in a kinematic chain, is known as
Structure
Machine
Inversion
Compound mechanism
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
Which of the following is an inversion of a double slider crank chain?
Oldham's coupling
Elliptical trammel
Scotch yoke mechanism
All of these
When a point at the end of a link moves with constant angular velocity, its acceleration will have
Radial component only
Tangential component only
Coriolis component only
Radial and tangential components both
The example of lower pair is
Shaft revolving in a bearing
Straight line motion mechanisms
Automobile steering gear
All of the above
The arrangement is called bevel gearing, when two __________ are connected by gears.
Intersecting and coplanar shafts
Nonintersecting and non-coplanar shafts
Parallel and coplanar shafts
Parallel and non-coplanar shafts
Elements of pairs held together mechanically is known as
Closed pair
Open pair
Mechanical pair
Rolling pair
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
3
4
5
Coriolis component acts
Perpendicular to sliding surfaces
Along sliding surfaces
Somewhere in between above two
None of the above
An automobile steering gear is an example of
Sliding pair
Rolling pair
Lower pair
Higher pair
A chain comprises of 5 links having 5 joints. Is it kinematic chain?
Yes
No
It is a marginal case
Data are insufficient to determine it
To connect two parallel and coplanar shafts the following type of gearing is used
Spur gear
Bevel gear
Spiral gear
None of the above
If the controlling force line for a spring controlled governor when produced intersects the Y-axis at the origin, then the governor is said to be
Stable
Unstable
Isochronous
None of these
The pitching of a ship produces forces on the bearings which act __________ to the motion of the ship.
Vertically and parallel
Vertically and perpendicular
Horizontally and parallel
Horizontally and perpendicular
In a screw jack, the effort required to lift the load W is given by (where α = Helix angle, and φ = Angle of friction)
P = W tan(α - φ)
P = W tan(α + φ)
P = W tan(φ - α)
P = W cos(α + φ)
Klein's construction is useful to determine
Velocity of various parts
Acceleration of various parts
Displacement of various parts
Angular acceleration of various parts
A typewriter mechanism has 7 numbers of binary joints, six links and none of higher pairs. The mechanism is
Kinematically sound
Not sound
Soundness would depend upon which link is kept fixed
Data is not sufficient to determine same
A shaft carrying three rotors will have
No node
One node
Two nodes
Three nodes
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
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
An eccentric sheave pivoted at one point rotates and transmits oscillatory motion to a link whose one end is pivoted and other end is connected to it. This mechanism has
2 links
3 links
4 links
5 links
In considering friction of a V-thread, the virtual coefficient of friction (μ₁) is given by
μ₁ = μ sinβ
μ₁ = μ cosβ
μ₁ = μ/sinβ
μ₁ = μ/cosβ