Machine Kinematics Multiple Choice Questions on “Inversions of Four Bar Chain”.
1. Match list I with list II
List I List II
A. Quick return mechanism 1. Lathe
B. Apron mechanism 2. Milling machine
C. Indexing mechanism 3. Shaper
D. Regulating wheel 4. Centreless grinding
a) A-3,B-2,C-1,D-4
b) A-2,B-3,C-4,D-1
c) A-4,B-2,C-3,D-1
d) A-3,B-1,C-2,D-4
Answer: d
Clarification: Quick return mechanism – Shaper
Apron mechanism – Lathe
Indexing mechanism – Milling machine
Regulating wheel – Centreless grinding
2. A point on a link connecting a double slider crank chain will trace a
a) straight line
b) circle
c) parabola
d) ellipse
Answer: d
Clarification: The point on connecting link traces an elliptical path.
3. A wheel is rolling on a straight level track with a uniform velocity ‘v’. The instantaneous velocity of a point on the wheel lying at the mid-point of a radius
a) varies between 3 v/2 and -v/2
b) varies between v/2 and -v/2
c) varies between 3 v/2 and -v/2
d) does not vary and is equal to v
Answer: b
Clarification: None
4. A four-bar chain has
a) all turning pairs
b) one turning pair and the others are sliding pairs
c) one sliding pair and the others are turning pairs
d) all sliding pairs
Answer: a
Clarification: A four-bar linkage, also called a four-bar, is the simplest movable closed chain linkage. It consists of four bodies, called bars or links, connected in a loop by four joints. Generally, the joints are configured so the links move in parallel planes, and the assembly is called a planar four-bar linkage.
5. The mechanism in a shaping machine is
a) a closed 4-bar chain having 6 revolute pairs
b) a closed 6-bar chain having 6 revolute pairs
c) a closed 4-bar chain having 2 revolute and 2 sliding pairs
d) an inversion of single slider crank chain
Answer: d
Clarification: Shaping machines use quick return mechanism which are either Whitworth quick return mechanism or crank and slotted lever quick return mechanism. These are inversions of single slider crank chain.
6. The number of inversions of a slider crank chain is
a) 6
b) 5
c) 4
d) 3
Answer: c
Clarification: A slider crank chain has 4 links and by fixing each link, one at a time, we get 4 different mechanisms, each of which is an inversion. Hence, a slider crank chain has 4 inversions.
7. Which of the following is an inversion of single slider crank chain?
a) Elliptical Trammel
b) Hand Pump
c) Oldham’s Coupling
d) Scotch Yoke
Answer: b
Clarification: Hand pump is an inversion of single slider crank chain.
8. Which of the following are the inversions of double slider crank chain?
1. Oldhan coupling
2. Whitworth quick return mechanism
3. Beam engine mechanism
4. Elliptical Trammel mechanism
The correct answer codes are
a) 1 and 2
b) 1 and 4
c) 2, 3 and 4
d) 1, 2 and 3
Answer: b
Clarification: Oldham coupling and Elliptical trammel are inversions of double slider crank chain.
Whitworth quick return mechanism is an inversion of single slider crank chain. Beam engine mechanism is an inversion of 4-bar linkage.
9. Which of the following is an inversion of single slider crank chain?
a) Beam engine
b) Watt’s indicator mechanism
c) Elliptical Trammel
d) Oscillating cylinder engine
Answer: d
Clarification: Oscillating cylinder engine is an inversion of single slider crank chain.
10. Oldham’s coupling is used to connect two shafts which are
a) intersecting
b) parallel
c) perpendicular
d) co-axial
Answer: b
Clarification: Oldham’s coupling is used to connect slightly offset parallel shafts.