Increases
Decreases
Remain same
None of these
A. Increases
Low
High
Medium
None of these
d/2
d/3
3d/4
d/4
Metric
Buttress
Square
NPT (national pipe threads)
Acts when external load is applied
Becomes zero when external load is removed
Is independent of external loads
Is always harmful
One smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly is middle of nut and then slot reduced by tightening a screw
A hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin spitted and bent in reverse direction at other end
Tensile stress
Compressive stress
Direct shear stress
Torsional shear stress
Diameter of bolt
0.75 × diameter of bolt
1.25 × diameter of bolt
1.5 × diameter of bolt
Dun cylinder
Hollow shaft
Solid shaft
Thick cylinder
A taper key which fits half in the key way of hub and half in the key way of shaft
A taper key which fits in a key way of the hub and is flat on the shaft
A taper key which fits in a key way of the hub and the bottom of the key is shaped to fit the curved surface of the shaft
Provided in pairs at right angles and each key is to withstand torsion in one direction only
40
50
70
100
Both sides of the actual size
One side of the actual size
One side of the nominal size
Both sides of the nominal size
Brittle materials
Ductile materials
Elastic materials
Plastic materials
5 N-m
7 N-m
10 N-m
15 N-m
Thick lubricated bearings
Plastic bearings
Antifriction bearings
Thin lubricated bearings
The stress concentration in static loading is more serious in ductile materials and less serious in brittle materials
The stress concentration in static loading is more serious in brittle materials and less serious in ductile materials
The toughness of a material increases when it is heated
The shear stress in a beam varies from zero at the neutral surface and maximum at the outer fibres
Margin
Pitch
Back pitch
Diagonal pitch
Ductile materials
Brittle materials
Equally serious in both cases
Depends on other factors
Uniform velocity
Simple harmonic motion
Uniform acceleration and retardation
Cycloidal motion
One smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly in middle of nut and then slot reduced by tightening a screw
A hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter spitted and bent in reverse direction at other end
Which are perfectly aligned
Which are not in exact alignment
Have lateral misalignment
Whose axes intersect at a small angle
Handle of a hand pump
Hand wheel of a punching press
Lever of a loaded safety valve
A pair of tongs
One smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly in middle of nut and then slot reduced by tightening screw
A hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin splitted and bent in reverse direction at the other end
Self locking bolts
Designed for shock load
Used in aircraft application
Provided with hexagonal depression in head
Parallel
Perpendicular
Both A and B
None of these
An axial compressive force
A tangential force
An axial tensile force
Any one of these
More than 50 %
Less than 50 %
Equal to 50 %
None of these
Surface
Just below the surface
Within the core
None of the above
Prevent the belt from running off the pulley
Increase the power transmission capacity
Increase the belt velocity
Prevent the belt joint from damaging the belt surface
Which are perfectly aligned
Which are not in exact alignment
Which have lateral misalignment
Whose axes intersect at a small angle
5 mm
10 mm
15 mm
25 mm