Machine Kinematics

Types of Friction

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Co-efficient of rolling friction is _______________ than co-efficient of sliding friction.
greater
equal to
lesser
none of the mentioned
Explanation:
For the same pair of surfaces, co-efficient of rolling friction is lesser than co-efficient of sliding friction.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
_____________ friction is the value of the limiting friction just before slipping occurs.
Dynamic
Static
Sliding
Rolling
Explanation:
Static friction is the force of friction experienced by a body when it is at rest.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
The co-efficient of dynamic friction is _______________ than static friction.
greater
equal to
lesser
none of the mentioned
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.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
When a body rolls over another, frictional force experienced by the body is known as _______________ friction.
sliding
rolling
static
none of the mentioned
Explanation:
When a body slides over another, the frictional force experienced by the body is known as sliding friction.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
When a body slides over another, the frictional force experienced by the body is known as ____________ friction.
sliding
rolling
static
none of the mentioned
Explanation:
When a body slides over another, the frictional force experienced by the body is known as sliding friction.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
____________friction is the force of friction experienced by a body when it is in motion.
Dynamic
Static
Sliding
Rolling
Explanation:
Dynamic friction is the force of friction experienced by a body when it is in motion.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
_____________ friction is the force of friction experienced by a body when it is at rest.
Dynamic
Static
Sliding
Rolling
Explanation:
Static friction is the force of friction experienced by a body when it is at rest.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
_____________ friction is the value of frictional force after slipping has occurred.
Dynamic
Static
Sliding
Rolling
Explanation:
Dynamic friction is the force of friction experienced by a body when it is in motion.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Co-efficient of sliding friction for steel is
0.030
0.70
0.18
0.004
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.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Co-efficient of sliding friction for rubber on concrete is
0.030
0.70
0.18
0.004
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.