The endurance limit of a material with finished surface in comparison to rough surface is
More
Less
Same
More or less depending on quantum of load
Correct Answer :
A. More
Related Questions
The centrifugal tension in belts
Decreases the power transmitted
Increases the power transmitted
Increase the wrap angle
Increases the belt tension without increasing power transmission
In the levers of first type, the mechanical advantage is __________ one.
Less than
Equal to
More than
None of these
The pitch of threads on a Jock nut in comparison to pitch of nut is
Same
Coarser
Finer
Very fine
The design of shafts made of brittle materials is based on
Guest's theory
Rankine's theory
St Venant's theory
Von Mises theory
Aircraft body is usually fabricated by
Welding
Pre-casting
Riveting
Casting
The velocity of sliding ________ the distance of the point of contact from the pitch point.
Is directly proportional to
Is inversely proportional to
Is equal to cos φ multiplied by
Does not depend upon
For longitudinal joint in boilers, the type of joint used is
Butt joint with single cover plate
Butt joint with double cover plate
Lap joint with one ring overlapping the other
Any one of the above
The property of a material which enables it to resist fracture due to high impact loads is known as
Elasticity
Endurance
Strength
Toughness
The shearing stresses in the inner face as compared to outer face of the wire in a heavy close coiled spring is
Larger
Smaller
Equal
Larger/smaller depending on diameter of spring coil
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
Whether any core is required in wire ropes
Yes
No
Sometimes
Rarely
The endurance limit of a material with finished surface in comparison to rough surface is
More
Less
Same
More or less depending on quantum of load
According to Unwin's formula, the relation between the diameter of rivet hole (d) and the thickness of plate (t) is given by (where d and t are in mm)
d = t
d = 1.6 t
d = 2t
d = 6t
Cap screws are
Similar to small size tap bolts except that a greater variety of shapes of heads are available
Slotted for a screw driver and generally used with a nut
Used to prevent relative motion between parts
Provided with detachable caps
In block brakes, the ratio of shoe width to wheel diameter is taken between
0.1 and 0.25
0.25 and 0.50
0.50 and 0.75
0.75 and 1
The centre distance between two meshing involute gears is equal to
(Sum of base circle radii)/cosφ
(Difference of base circle radii)/cosφ
(Sum of pitch circle radii)/cosφ
(Difference of pitch circle radii)/cosφ
The face of the tooth is the
Surface of the top of the tooth
Surface of the tooth above the pitch surface
Surface of the tooth below the pitch surface
Width of the tooth measured along the pitch circle
In the case of an elastic bar fixed at upper end and loaded by a falling weight at lower end, the shock load produced can be decreased by
Decreasing the cross-section area of bar
Increasing the cross-section area of bar
Remain unaffected with cross-section area
Would depend upon other factors
The allowable static stress for steel gears is approximately __________ of the ultimate tensile stress.
One-fourth
One-third
One-half
Double
A circular shaft can transmit a torque of 5 kN-m. If the torque is reduced to 4 kN-m, then the maximum value of bending moment that can be applied to the shaft is
1 kN-m
2 kN-m
3 kN-m
4 kN-m
Guest's theory of failure is applicable for following type of materials
Brittle
Ductile
Elastic
Plastic
Which is correct statement? Stress concentration in static loading is
Very serious in brittle materials and less serious in ductile materials
Very serious in ductile materials and less serious in brittle materials
Equally serious in both types of materials
Seriousness would depend on other factors
In helical gears, the right hand helixes on one gear will mesh __________ helixes on the other gear.
Right hand
Left hand
Both A and B
None of these
A spring of stiffness 1000 N/m is stretched initially by 100 mm from the undeformed position. The work required to stretch it by another 100 mm is
5 N-m
7 N-m
10 N-m
15 N-m
When the connected members are very yielding (soft gasket) as compared to the bolt, 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
The strength of a riveted joint is equal to
Tearing strength of plate (Pt)
Shearing strength of rivet (Ps)
Crushing strength of rivet (Pc)
Least value of Pt Ps and Pc
In standard taper roller bearings, the angle of taper of outer raceway is
5°
8°
15°
25°
The rolling contact bearings are known as
Thick lubricated bearings
Plastic bearings
Antifriction bearings
Thin lubricated bearings
In hydrostatic bearings
The Oil film pressure is generated only by the rotation of the journal
The oil film is maintained by supplying oil under pressure
Do not require external supply of lubricant
Grease is used for lubrication
Rankine's theory is used for
Brittle materials
Ductile materials
Elastic materials
Plastic materials