Kinematic Pair

Question 1
Marks : +2 | -2
Pass Ratio : 100%
The relation l = 2/3(j+2) apply to kinematic chains in which lower pairs are used. This may be used to kinematic chains in which higher pairs are used, but each higher pair may be taken as equivalent to
one lower pair and two additional links
two lower pairs and one additional link
two lower pairs and two additional links
all of the mentioned
Explanation:
None
Question 2
Marks : +2 | -2
Pass Ratio : 100%
In an open pair, the two elements of a pair
have a surface contact when in motion
have a line or point contact when in motion
are kept in contact by the action of external forces, when in motion
are not held mechanically
Explanation:
When the two elements of a pair are not held mechanically, they are called open pair.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
When the two elements of a pair have _____________ when in motion, it is said to a lower pair.
line or point contact
surface contact
permit relative motion
none of the mentioned
Explanation:
When the two elements of a pair have surface contact when relative motion, takes place and the surface of one element slides over the surface of the other, the pair formed is known as lower pair. It will be seen that sliding pairs, turning pairs and screw pairs form lower pairs.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
The relation between number of pairs(p) forming a kinematic chain and the number of links(l) is
l = 2p – 2
l = 2p – 3
l = 2p – 4
l = 2p – 5
Explanation:
If each link is assumed to form two pairs with adjacent links, then the relation between the number of pairs(p) forming a kinematic chain and the number of links(l) may be expressed in the form of an equation : l = 2p – 4
Question 5
Marks : +2 | -2
Pass Ratio : 100%
The relation between number of links(l) and number of joints(j) in a kinematic chain is
l = 1/2 (j+2)
l = 2/3 (j+2)
l = 3/4 (j+2)
l = j+4
Explanation:
Another relation between the number of links (l) and the number of joints(j) which constitute a kinematic chain is given by the expression : l = 2/3 (j+2)
Question 6
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Pass Ratio : 100%
A combination of kinematic pairs, joined in such a way that the relative motion between the links is completely constrained, is called a
structure
mechanism
kinematic chain
inversion
Explanation:
A kinematic chain is defined as a combination of kinematic pairs, joined in such a way that each link forms a part of two pairs and the relative motion between the links or elements is completely or successfully constrained.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
In a force-closed pair, the two elements of a pair are not held together mechanically.
True
False
Explanation:
When the two elements of pair are not connected mechanically but are kept in contact by the action of external forces, the pair is said to be a forced-closed pair.
Question 8
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Pass Ratio : 100%
The two elements of a pair are said to form a higher pair, when they
have a surface contact when in motion
have a line or point contact when in motion
are kept in contact by the action of external forces, when in motion
permit relative motion
Explanation:
When the two elements of a pair have a line or point contact when relative motion takes place and the motion between the two elements is partly turning and partly sliding, then the pair is known as higher pair.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
The sliding pairs, turning pairs and screw pairs form lower pairs.
True
False
Explanation:
When the two elements of a pair have surface contact when relative motion, takes place and the surface of one element slides over the surface of the other, the pair formed is known as lower pair. It will be seen that sliding pairs, turning pairs and screw pairs form lower pairs.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
The two elements of a pair are said to form a ___________ when they permit relative motion between them.
open pair
kinematic pair
higher pair
lower pair
Explanation:
The two links or elements of a machine, when in contact with each other, are said to form a pair. If the relative motion between them is completely or successfully constrained, the pair is known as kinematic pair.