Properties of Instantaneous Centre

Question 1
Marks : +2 | -2
Pass Ratio : 50%
Which is the false statement about the properties of instantaneous centre?
at the instantaneous centre 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 centre have the same linear velocity to the third rigid link
the double centre can be denoted either by O21 or O12, but proper selection should be made
Explanation:
The following properties of the instantaneous centre are important from the subject point of view :
Question 2
Marks : +2 | -2
Pass Ratio : 50%
The absolute acceleration of any point P in a link about center of rotation O is
along PO
perpendicular to PO
at 450 to PO
none of the mentioned
Explanation:
The coriolis component of acceleration is always perpendicular to the link.
Question 3
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Pass Ratio : 50%
In a rigid link OA, velocity of A w.r.t. O will be
parallel to OA
perpendicular to OA
at 450 to OA
along AO
Explanation:
None.
Question 4
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Pass Ratio : 50%
According to Kennedy’s theorem, if three bodies have plane motions, their instantaneous centres lie on
a triangle
a point
two lines
a straight line
Explanation:
The Aronhold Kennedy’s theorem states that if three bodies move relatively to each other, they have three instantaneous centres and lie on a straight line.
Question 5
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Pass Ratio : 50%
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
at 450 to line
none of the mentioned
Explanation:
A link is rotating about O. Velocity of point P on link w.r.t. point Q on link will be perpendicular to PQ.
Question 6
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Pass Ratio : 50%
The number of links and instantaneous centers in a reciprocating engine mechanism are
4,4
4,5
5,4
4,6
Explanation:
First of all, determine the number of instantaneous centres (N) by using the relation
Question 7
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Two systems shall be dynamically equivalent when
the mass of two are same
c.g. of two coincides
M.I. of two about an axis through c.g. is equal
all of the mentioned
Explanation:
None.
Question 8
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Pass Ratio : 50%
A link is rotating about O. Velocity of point P on link w.r.t. point Q on link will be perpendicular to
OP
OQ
PQ
line in between OP and OQ
Explanation:
A link is rotating about O. Velocity of point P on link w.r.t. point Q on link will be perpendicular to PQ.
Question 9
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Pass Ratio : 50%
The total number of instantaneous centers for a mechanism of n links is
n(n – 1)/2
n
n – 1
n(n – 1)
Explanation:
The number of pairs of links or the number of instantaneous centres is the number of combinations of n links taken two at a time. Mathematically, number of instantaneous centres,
Question 10
Marks : +2 | -2
Pass Ratio : 50%
Instantaneous center of rotation of a link in a four bar mechanism lies on
right side pivot of this link
left side pivot of this link
a point obtained by intersection on extending adjoining links
none of the mentioned
Explanation:
None.