In a ball bearing, ball and bearing forms a
Turning pair
Rolling pair
Screw pair
Spherical pair
Correct Answer :
B. Rolling pair
Related Questions
Which of the following statement is wrong?
The difference between the maximum and minimum energies is called maximum fluctuation of energy
The coefficient of fluctuation of speed is the ratio of maximum fluctuation of speed to the mean speed
The variations of energy above and below the mean resisting torque line is known as fluctuation of energy
None of the above
The frictional torque transmitted in a flat pivot bearing, considering uniform pressure, is (where μ = Coefficient of friction, W = Load over the bearing, and R = Radius of bearing surface)
(1/2) μ W R
(2/3) μ W R
(3/4) μ W R
μ W R
In a drag link quick return mechanism, the shortest link is always fixed. The sum of the shortest and longest link is
Equal to sum of other two
Greater than sum of other two
Less than sum of other two
There is no such relationship
When a shaking force is transmitted through the springs, damping becomes detrimental when the ratio of its frequency to the natural frequency is greater than
0.25
0.5
1
2
In a flat collar pivot bearing, the moment due to friction is proportional to
(r₁² - r₂²)/(r₁ - r₂)
(r₁² - r₂²)/(r₁ + r₂)
(r₁³ - r₂³)/(r₁² - r₂²)
(r₁³ - r₂³)/(r₁ - r₂)
Which of the following would constitute a link?
Piston, piston rod and cross head
Piston and piston rod
Piston rod and cross head
Piston, crank pin and crank shaft
The size of cam depends upon
Base circle
Pitch circle
Prime circle
Pitch curve
Which of the following is a spring controlled governor?
Hartnell governor
Hartung governor
Wilson-Hartnell governor
All of these
If two moving elements have surface contact in motion, such pair is known as
Sliding pair
Rolling pair
Surface pair
Higher pair
A fixed gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by an arm. The number of turns made by the smaller gear for one revolution of arm about the centre of bigger gear is
2
4
3
None of the above
The direction of linear velocity of any point on a link with respect to another point on the same link is
Parallel to the link joining the points
Perpendicular to the link joining the points
At 45° to the link joining the points
None of the above
In involute gears, the pressure angle is
Dependent on the size of teeth
Dependent on the size of gears
Always constant
Always variable
The height of a Watt's governor (in metres) is equal to (where N = Speed of the arm and ball about the spindle axis)
8.95/N²
89.5/N²
895/N²
8950/N²
Frequency of vibrations is usually expressed in
Number of cycles per hour
Number of cycles per minute
Number of cycles per second
None of these
To obviate axial thrust, following gear drive is used
Double helical gears having opposite teeth
Double helical gears having identical teeth
Single helical gear in which one of the teeth of helix angle a is more
Mutter gears
The train value of a gear train is
Equal to velocity ratio of a gear train
Reciprocal of velocity ratio of a gear train
Always greater than unity
Always less than unity
Torsional vibrations are said to occur when the particles of a body moves
Perpendicular to its axis
Parallel to its axis
In a circle about its axis
None of these
In multi V-belt transmission, if one of the belt is broken, we have to change the
Broken belt
Broken belt and its adjacent belts
All the belts
There is no need of changing any one as remaining belts can take care of transmission of load
The number of links in pantograph mechanism is equal to
2
3
4
5
An exact straight line motion mechanism is a
Scott-Russell's mechanism
Hart's mechanism
Peaucellier's mechanism
All of these
The ratio of maximum fluctuation of energy to the workdone per cycle is called
Fluctuation of energy
Maximum fluctuation of energy
Coefficient of fluctuation of energy
None of these
When the two elements of a pair have a surface contact when relative motion takes place and the surface of one element slides over the surface of the other, the pair formed is known as a
Lower pair
Higher pair
Self-closed pair
Force-closed pair
In a reciprocating steam engine, which of the following forms a kinematic link?
Cylinder and piston
Piston rod and connecting rod
Crankshaft and flywheel
Flywheel and engine frame
When two links are connected by a pin joint, their instantaneous centre lies
On their point of contact
At the centre of curvature
At the centre of circle
At the pin joint
The working depth of a gear is the radial distance from the
Pitch circle to the bottom of a tooth
Pitch circle to the top of a tooth
Top of a tooth to the bottom of a tooth
Addendum circle to the clearance circle
If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then energy stored in the latter at the same speed will be
Four times the first one
Same as the first one
One fourth of the first one
One and a half times the first one
In the two rotor system as shown in the below figure (I₁ < I₂), a node of vibration is situated 
Between I₁, and I₂ but nearer I₁
Between I₁, and I₂ but nearer to I₂
Exactly in the middle of the shaft
Nearer to I₁ but outside
Which of the following is a pendulum type governor?
Watt governor
Porter governor
Hartnell governor
None of these
Transmission angle is the angle between
Input link and coupler
Input link and fixed link
Output link and coupler
Output link and fixed link
A body is said to be under forced vibrations, when
There is a reduction in amplitude after every cycle of vibration
No external force acts on a body, after giving it an initial displacement
A body vibrates under the influence of external force
None of the above