Engineering Questions with Answers - Multiple Choice Questions
Machine Kinematics MCQ – Types of Friction
1 - Question
____________ friction is the force of friction experienced by a body when it is at rest.
a) Dynamic
b) Static
c) Sliding
d) Rolling
View Answer
Answer: b
Explanation: Static friction is the force of friction experienced by a body when it is at rest.
OR Static friction is the value of the limiting friction just before slipping occurs.
2 - Question
_____________ friction is the value of the limiting friction just before slipping occurs.
a) Dynamic
b) Static
c) Sliding
d) Rolling
View Answer
Answer: b
Explanation: Static friction is the force of friction experienced by a body when it is at rest.
OR Static friction is the value of the limiting friction just before slipping occurs.
3 - Question
____________friction is the force of friction experienced by a body when it is in motion.
a) Dynamic
b) Static
c) Sliding
d) Rolling
View Answer
Answer: a
Explanation: Dynamic friction is the force of friction experienced by a body when it is in motion.
OR Dynamic friction is the value of frictional force after slipping has occurred.
4 - Question
_____________ friction is the value of frictional force after slipping has occurred.
a) Dynamic
b) Static
c) Sliding
d) Rolling
View Answer
Answer: a
Explanation: Dynamic friction is the force of friction experienced by a body when it is in motion.
OR Dynamic friction is the value of frictional force after slipping has occurred.
5 - Question
When a body slides over another, the frictional force experienced by the body is known as ____________ friction.
a) sliding
b) rolling
c) static
d) none of the mentioned
View Answer
Answer: a
Explanation: When a body slides over another, the frictional force experienced by the body is known as sliding friction.
When a body rolls over another, frictional force experienced by the body is known as rolling friction.
6 - Question
When a body rolls over another, frictional force experienced by the body is known as _______________ friction.
a) sliding
b) rolling
c) static
d) none of the mentioned
View Answer
Answer: b
Explanation: When a body slides over another, the frictional force experienced by the body is known as sliding friction.
When a body rolls over another, frictional force experienced by the body is known as rolling friction.
7 - Question
Co-efficient of rolling friction is _______________ than co-efficient of sliding friction.
a) greater
b) equal to
c) lesser
d) none of the mentioned
View Answer
Answer: c
Explanation: For the same pair of surfaces, co-efficient of rolling friction is lesser than co-efficient of sliding friction.
8 - Question
Co-efficient of sliding friction for rubber on concrete is
a) 0.030
b) 0.70
c) 0.18
d) 0.004
View Answer
Answer: b
Explanation: Co-efficient of sliding friction for rubber on concrete is 0.70. When tires made of rubber rolls on concrete, co-efficient of rolling friction becomes 0.030.
9 - Question
Co-efficient of sliding friction for steel is
a) 0.030
b) 0.70
c) 0.18
d) 0.004
View Answer
Answer: c
Explanation: Co-efficient of sliding friction for steel is 0.18. When railway wheels made of steel rolls on rails made of steel, the co-eficient of rolling friction becomes 0.004.
10 - Question
The co-efficient of dynamic friction is _______________ than static friction.
a) greater
b) equal to
c) lesser
d) none of the mentioned
View Answer
Answer: c
Explanation: Since the value of F in dynamic friction is little lesser than in static friction, the ratio F/N and hence, the co-efficient of dynamic friction will also be a little lesser than static friction.