1. The motion of a shaft in a circular hole is an example of
a) completely constrained motion
b) incompletely constrained motion
c) successfully constrained motion
d) none of the mentioned
Explanation: When the motion between a pair can take place in more than one direction, then the motion is called an incompletely constrained motion. A circular bar or shaft in a circular hole, is an example of an incompletely constrained motion as it may either rotate or slide in a hole.
2. The example of successfully constrained motion is a
a) motion of an I.C. engine valve
b) motion of the shaft between a foot-step bearing
c) piston reciprocating inside an engine cylinder
d) all of the mentioned
Explanation: When the connection between the elements forming a pair is such that the constrained motion is not completed by itself, but by some other means, the motion is said to be a successfully constrained motion. so, the above examples have successfully constrained motion.
3. Which of the following statement is wrong?
a) A round bar in a round hole form a turning pair
b) A square bar in a square hole form a sliding pair
c) A vertical shaft in a foot step bearing forms a successful constraint
d) All of the mentioned
Explanation: A vertical shaft in a foot step bearing forms a successful constraint
4. When the nature of contact between the element of a pair is such that it can only slide relative to the other, the pair is known as a
a) screw pair
b) spherical pair
c) turning pair
d) sliding pair
Explanation: When the nature of contact between the element of a pair is such that one element can turn abut the other by screw threads, the pair is known as a screw pair. When the nature of contact between the element of a pair is such that it can only slide relative to the other, the pair is known as a sliding pair.
5. When the nature of contact between the element of a pair is such that it can turn or revolve about a fixed axis, the pair is known as a rolling pair.
a) True
b) False
Explanation: When the nature of contact between the element of a pair is such that it can turn or revolve about a fixed axis, the pair is known as a turning pair.
6. When the nature of contact between the element of a pair is such that one element can turn abut the other by screw threads, the pair is known as a
a) screw pair
b) spherical pair
c) turning pair
d) sliding pair
Explanation: When the nature of contact between the element of a pair is such that one element can turn abut the other by screw threads, the pair is known as a screw pair.
7. A sliding pair has a completely constrained motion
a) True
b) False
Explanation: When the nature of contact between the element of a pair is such that it can only slide relative to the other, the pair is known as a sliding pair and it has a completely constrained motion.
8. Which of the following is an example of sliding pair?
a) Piston and cylinder of a reciprocating steam engine
b) Shaft with collars at both ends fitted into a circular hole
c) Lead screw of a lathe with nut
d) Ball and a socket joint
Explanation: When the nature of contact between the element of a pair is such that it can only slide relative to the other, the pair is known as a sliding pair and can be found in piston and cylinder of a reciprocating steam engine.
9. The ball and socket joint is an example of screw pair.
a) True
b) False
Explanation: The ball and socket joint is an example of spherical pair. When the two elements of a pair are connected in such a way that one element turns or swivels about the other fixed element, the pair formed is called a spherical pair.
10. Which of the following is an open pair?
a) Ball and socket joint
b) Journal bearing
c) Lead screw and nut
d) Cam and follower
Explanation: Ball and socket joint