In case of lower pairs
there is no contact between the two elements
there is contact only at lower point of the two elements while in motion
there is point or line contact between the two-elements while in motion
there is surface contact between the two elements while in motion
Which amongst the following constitutes a higher pair?
a ball and socket joint
toothed gearing
universal joint
cycle wheels turning on their axles
Which one of the followings is a lower pair?
cam and follower
toothed gearing
shaft in a bearing
ball and race in bearing
Various kinematic pairs are given below. Choose the lower pair/pairs:
cam and follower
belt and pulley
crank pin rotating in a connecting rod
roller and inner race of roller bearing
Pick the odd one out:
cam and follower
belt, rope and chain drive
ram and guides in a shaper
belt and pulley
ball and roller bearings
Two elements that permits relative motion which is completely constrained or successfully constrained constitute a
closed pair
lower pair
kinetic pair
mechanism
A pantograph is a mechanism or a kinetic arrangement comprising
lower pairs
rolling pairs
turning pairs
spherical pairs
The number of links in a pantograph is
3
4
5
6
All of the following statements about a kinematic link correct expect
A kinematic link is a machine part which moves relative to some part
A link may consist of several parts which are rigidly fastened together
A link must be a rigid and resistant body
A link is capable of transmitting the required forces with negligible deformation
Which of the following systems has 8-links?
Hart mechanism
Peaucellier mechanism
Whitworth quick return mechanism
Scotch yoke mechanism
Piston, piston rod and cross head of a steam engine constitute
one link
two links
three links
four links
Connecting rod, big and small end brasses, caps and bolts constitute
one link
two links
three links
four links
Crank, connecting rod, cylinder and piston of a steam engine constitute
one link
two links
three links
four links
Which of the following exemplifies a kinematic link?
Piston rings, piston and connecting rod
Piston rings, piston and cylinder
Piston rings, piston and gudgeon pin
Piston rings, piston, piston rod and cross head
A kinematic pair consists of
pair of elements having line or point contact
pair of elements having surface contact
two elements that permit relative motion
two elements which are mechanically held together
Identify the incorrect combination:
Cross head and guides : sliding pair
A bolt and nut : turning pair
A ball and socket joint : spherical pair
Ball bearing and roller bearing : rolling pair
Point out the screw pair :
tail stock on the lathe bed
lathe spindle supported in head stock
lead screw of a lathe with nut
pen supports joint in a pen stand
Type writer constitutes a
machine
mechanism
structure
inversion
Cam and follower mechanism constitutes a kinematic pair of the type
lower and open
higher and open
lower and closed
higher and closed
A ball and socket joint constitutes a spherical pair having
no degree of freedom
one degree of freedom
two degrees of freedom
three degrees of freedom
A completely constrained motion occurs in case of
circular bar or shaft in a circular hole
motion of an I.C. engine valves
foot step bearing and roller of a vertical turbine
circular shaft, with collars at each end, in a circular hole
The motion of circular rod in a circular hole is an example of
successfully constrained motion
completely constrained motion
partially constrained motion
incompletely constrained motion
The arrangement comprised by a rotating shaft in foot step bearing
does not exemplify a kinematic pair
has incompletely constrained motion
has successfully constrained motion
has completely constrained motion
Which of the followings is a wrong statement?
each part of a machine which moves relative to some other part is called kinematic link
The motion of an I.C. engine valve is successfully constrained
A kinematic chain is a combination of kinematic pair in which one link is fixed
When one of the links of a kinematic chain is fixed, the resulting mechanism is known as inversion of the original kinematic chain
A kinematic chain consists of a chain of links
in space with constrained motion
with incompletely constrained motion
with atleast one link fixed and successfully constrained motion
with atleast one link fixed and completely constrained motion
Inversion of a mechanism is
changing of a higher pair to lower pair
obtained by fixing different links in a kinematic chain
turning it upside down
obtained by reversing the input and output motion
Inversions of a kinetic chain
modify relative motion of one link relative to another
completely change the motion of links relative to each other
keep relative motions of links unchanged with respect to one another
have no effect on absolute motion of a link
For a kinematic chain constituted by lower pairs, the number of links l and the number of joins j are correlated by the expression
l = 1(j + 2)
3
l = 2(j + 2)
3
l = 1( j + 2)
2
l = (j + 2)
The number of links l and the number of pairs p in a kinematic chain conform to the relation
l = p – 4
l = 2p – 4
l = 2p + 1
l = 2(p – 1)
If the number of links in a mechanism is 6, the number of pairs would be
4
5
6
7
Is it possible to have kinematic chain with 5 links and 5 joints?
no
yes
marginal case
data insufficient to make any prediction
A slider crank chain consists of following number of turning and sliding pairs :
1,3
2,2
3,1
4,0
0,4
The criterion of constraint for a kinematic chain having plane motion is given by the equation
where j = number of binary joints in the chain
H = number of higher kinematic pairs
l = number of links in the chain
2j + H = 3l – 4
2 (j + H) = 3(l + 1)
j + H = 3l – 1
2(j + H) = 3(l + 2)
A six link chain with no higher pairs has 5 binary joints and 1 ternary joint. Is the chain
constrained
unconstrained
locked
no criterion exits to make such a prediction
The number of possible inversions for a mechanism with l number of links are
l – 1
l
l + 1
l + 2
A point on a link connecting double slider crank chain traces a ………………. path
parabolic
elliptic
hyperbola
straight line
The number of inversion of a double slider crank chain are
2
3
4
6
All of the following are inversion of slider crank chain, except
Whitworth quick return motion
Pendulum pump
Oldham’s coupling
Oscillating cylinder engine
Which amongst the followings is an inversion of double slider crank chain?
Engine indicator
Elliptical trammel
Quick return motion
Coupled wheels of a locomotive
An elliptical trammel has four pairs of the type
one pair turning and three pairs sliding
two pairs turning and two pairs sliding
three pairs turning and one pair sliding
all four pairs turning
Mid-point of the floating link of elliptical trammel traces a
circle
parabola
ellipse
straight line
Oldham’s coupling is used to connect two shafts
which change axis during transmission
which have lateral movement during power transmission
whose axis intersect
which have lateral misalignment
Two parallel shafts, the distance between whose axes is small and variable, are connected by
Clutch arrangement
Oldham’s coupling
Hook’s joint
Universal coupling
A Hook’s joint is used t connect
two parallel shafts
two intersecting shafts
two non-parallel intersecting shafts
two non-parallel, non-intersecting shafts
Which statement is not true about shafts joined by Hook’s joint?
the shaft rotate in opposite directions
the shafts may rotate at different angular speeds
the axis of the two shafts coincide
the angle between the axis of the two shafts can be altered whilst the shafts are in motion
A universal joint is an example of
lower pair
higher pair
rolling pair
sliding pair
A Davis steering gear consists of four bar mechanism with
one pair turning and three pairs sliding
two pairs turning and two pairs sliding
three pairs turning and pair sliding
all four pairs turning
all four pairs sliding
All of the following statements are correct, except
for a kinematic chain to be considered as a mechanism, one link should be fixed
the Ackermann steering gear consists of three pairs turning and one pair sliding
in automobiles, Hook’s joint is used between gear box and differential
a minimum of four kinematic pairs are required in a kinematic chain
Which of the following is a false statement?
the Hook’s joint consists of two forks
the Ackermann steering mechanism is preferred to Davis type in automobiles because it is mathematically correct in all positions
Watt-straight line mechanism is an approximate method for generating straight line path
Scott-Russel mechanism for generating straight line has two lower turning pairs and one lower sliding pair
Scotch Yoke mechanism is used for converting rotary motion into reciprocating motion
Identify the correct combinations between particular kinematic chain and its inversion/inversions
four bar chain : Ackermann steering gear
slider crank chain : Whitworth quick return motion
double slider crank chain : Oldham’s coupling
cross slider crank chain : Rapson’s slide
All combinations are correct