The ball bearings are provided with a cage
To reduce friction
To facilitate slipping of balls
To prevent the lubricant from flowing out
To maintain the balls at a fixed distance apart
Correct Answer :
D. To maintain the balls at a fixed distance apart
Related Questions
In composite or reverse laid ropes
Direction of twist of wires in strands is opposite to the direction of twist of strands
Direction of twist of wires and strands are same
Wires in two adjacent strands are twisted in opposite direction
Wires are not twisted
The shock absorbing capacity of a bolt can be increased by
Tightening it properly
Increasing shank diameter
Grinding the shank
Making shank diameter equal to core diameter of thread.
For applications involving high stresses in one direction only the following type of thread would be best suited
ISO metric thread
Acme thread
Square thread
Buttress thread
A coupling used to connect two perfectly aligned shafts, is
Muff coupling
Compression coupling
Flange coupling
All of these
The relation between the pitch of the chain (p) and pitch circle diameter of the sprocket (D) is given by (where T = Number of teeth on the sprocket)
p = D sin (90°/T)
p = D sin (120°/T)
p = D sin (180°/T)
p = D sin (360°/T)
Which of the following statement is correct?
The cold rolled shafting is stronger than hot rolled shafting
The hot rolled shafting is stronger than cold rolled shafting
The cold rolled and hot rolled shaftings are equally strong
The shafts are not made by rolling process
Rankine's theory of failure is applicable for following type of materials
Brittle
Ductile
Elastic
Plastic
When a close coiled helical spring is compressed, its wire is subjected to
Tension
Shear
Compression
All of the above
When a nut is tightened by placing a washer below it, the bolt will be subjected to following type of loads
Compression
Tension
Shear
Combined loads
The square threads are usually found on
Spindles of bench vices
Railway carriage couplings
Feed mechanism of machine tools
Screw cutting lathes
Which of the following statement is correct for gears?
The pitch circle diameter is equal to the product of module and number of teeth
The addendum is less than dedendum
The pitch circle is always greater than the base circle
All of the above
Lewis form factor for 14 ½° composite and full depth involute system is (where T = Number of teeth)
0.124 - (0.684/T)
0.154 - (0.912/T)
0.175 - (0.841/T)
None of these
The power transmitted by the belt drive can be increased by
Increasing the initial tension in the belt
Dressing the belt to increase the coefficient of friction
Increasing wrap angle by using idler pulley
All of the above methods
Fabric belts are used in industrial applications because
They are cheap
They can work at high temperature
They are unaffected by moisture and humidity
None of the above
Two rigid plates are clamped by means of bolt and nut with an initial force F. After tightening, a separating force P (P < F) is applied to the lower plate, which in turn acts on the nut. The tension in the both after this is
F + P
F P
P
F
The pitch diameter is the __________ diameter of an external or internal screw thread.
Effective
Smallest
Largest
None of these
The included angle in unified of American National threads is
60°
55°
47°
29°
An imaginary circle which by pure rolling action gives the same motion as the actual gear, is called
Addendum circle
Dedendum circle
Pitch circle
Clearance circle
For a shaft diameter of 100 mm, the number of bolts in a flange coupling should be
4
6
8
10
When the bolt is very yielding as compared to the connected members, then the resultant load on the bolt will be equal to the
Initial tension
External load applied
Sum of the initial tension and external load applied
Initial tension or external load, whichever is greater
Which of the following pipe joints would be suitable for pipes carrying steam?
Flanged
Threaded
Bell and spigot
Expansion
The fatigue life of a part can be improved by
Electroplating
Polishing
Coating
Shot peening
Two shafts will have equal strength, if
Diameter of both the shafts is same
Angle of twist of both the shafts is same
Material of both the shafts is same
Twisting moment of both the shafts is same
In skew bevel gearing, the axes of shafts are
Intersecting and the teeth are curved
Non-intersecting and nonparallel and the teeth are curved
Non-intersecting and non-parallel and the teeth are straight
None of the above
The shear stress in a beam varies from zero at the outer fibres to a maximum at the________.
Neutral surface
Upper surface
Lower surface
None of these
The plasticity is the property of a material which enables it to
Regain its original shape after deformation when the external forces are removed
Draw into wires by the application of a tensile force
Resist fracture due to high impact loads
Retain deformation produced under load permanently
A screw is said to be a self locking screw, if its efficiency is
Less than 50 %
More than 50 %
Equal to 50 %
None of these
If a spring is cut down into two springs, the stiffness of cut springs will be
Half
Same
Double
None of the above
The objective of idler pulley in belt drive is to
Decrease the tendency of belt to slip
Increase the power transmission capacity
Increase the wrap angle and belt tension
All the above objectives
Two helical springs of the same material and of equal circular crosssection, length and number of turns, but having radii 80 mm and 40 mm, kept concentrically (smaller radius spring within the larger radius spring), are compressed between two parallel planes with a load W. The inner spring will carry a load equal to
W/2
2W/3
W/9
8W/9