Machine Kinematics Multiple Choice Questions on “Mechanism – 1”.
1. A type-writer constitutes a machine.
a) True
b) False
Answer: b
Clarification: When a mechanism is required to transmit power or to do some particular type of work, it then becomes a machine.But in case of a typewriter there is no case of power transmission. Hence it is not a machine.
2. The method of obtaining different mechanisms by fixing in turn different links in a kinematic chain, is known as
a) structure
b) machine
c) inversion
d) compound mechanism
Answer: c
Clarification: We can obtain as many mechanisms as the number of links in kinematic chain by fixing, in turn,different links in a kinematic chain. This method is known as inversion of the mechanism.
3. If the number of links in a mechanism are equal to l, then the number of possible inversions are equal to
a) l – 2
b) l – 1
c) l
d) l + 1
Answer: c
Clarification: Whatever is the number of links in a mechanism, only that much number of inversion can be obtained.
4. Which of the following statement is correct as regard to the difference between a machine and a structure?
a) The parts of a machine move relative to one another, whereas the members of a structure do not move relative to one another.
b) The links of a machine may transmit both power and motion, whereas the members of a structure transmit forces only.
c) A machine transforms the available energy into some useful work, whereas in a structure no energy is transformed into useful work.
d) all of the mentioned
Answer: d
Clarification: None
5. A kinematic chain is known as a mechanism when
a) none of the links is fixed
b) one of the links is fixed
c) two of the links are fixed
d) none of the mentioned
Answer: b
Clarification: When one of the links of a kinematic chain is fixed, the chain is known as mechanism.
6. The inversion of a mechanism is
a) changing of a higher pair to a lower pair
b) turning its upside down
c) obtained by fixing different links in a kinematic chain
d) obtained by reversing the input and output motion
Answer: c
Clarification: We can obtain as many mechanisms as the number of links in kinematic chain by fixing, in turn,different links in a kinematic chain. This method is known as inversion of the mechanism.
7. The Grubler’s criterion for determining the degrees of freedom (n) of a mechanism having plane motion is
a) n = (l – 1) – j
b) n = 2(l – 1) – 2j
c) n = 3(l – 1) – 2j
d) n = 4(l – 1) – 3j
Answer: c
Clarification: None
8. The mechanism forms a structure, when the number of degrees of freedom (n) is equal to
a) 0
b) 1
c) 2
d) -1
Answer: a
Clarification: A structure can be formed only when the number of degrees of freedom is zero.
9. In a four bar chain or quadric cycle chain
a) each of the four pairs is a turning pair
b) one is a turning pair and three are sliding pairs
c) two are turning pairs and two are sliding pairs
d) three are turning pairs and one is a sliding pair
Answer: a
Clarification: Four bar chain or quadric cycle chain consists of four links, each of them forms a turning pair.
10. The mechanism in which two are turning pairs and two are sliding pairs, is called a
a) double slider crank chain
b) elliptical trammel
c) scotch yoke mechanism
d) all of the mentioned
Answer: d
Clarification: A double slider crank chain consists of two sliding pairs and two turning pairs. The inversions of a double slider crank chain are as follows:
a) elliptical trammel
b) scotch yoke mechanism
c) oldham’s coupling