Set 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
Similar to stud
Correct Answer :
C. Used to prevent relative motion between parts
Related Questions
According to I.B.R., when the thickness of the boiler shell (t) is less than 8 mm, then the diameter of the rivet hole (d) is obtained by
Equating tearing resistance of the plate to the shearing resistance of the rivets
Equating tearing resistance of the plate to the crushing resistance of the rivets
Equating shearing resistance to the crushing resistance of the rivets
None of the above
If threads on a bolt are left hand, threads on nut will be
Right hand with same pitch
Left hand with same pitch
Could be left or right hand
Right hand with fine pitch
In case of thick cylinders, the tangential stress across the thickness of cylinder is
Maximum at the outer surface and minimum at the inner surface
Maximum at the inner surface and minimum at the outer surface
Maximum at the inner surface and zero at the outer surface
Maximum at the outer surface and zero at the inner surface
A crankshaft is a __________ shaft.
Transmission
Machine
Machine frame
None of these
The taper on key is given on
Bottom side only
Top side only
On both sides
Any side
The dedendum is the radial distance from the
Pitch circle to the top of a tooth
Pitch circle to the bottom of a tooth
Top of a tooth to the bottom of a tooth
Addendum circle to the clearance circle
In order to ensure self locking in a screw jack, it is essential that helix angle is __________ friction angle.
Larger than
Smaller than
Equal to
None of these
The sleeve or muff coupling is designed as a
Dun cylinder
Hollow shaft
Solid shaft
Thick cylinder
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
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.
A bolt is designed on the basis of __________ with a large factor of safety.
Direct tensile stress
Direct compressive stress
Direct bending stress
Direct shear stress
The maximum stress due to stress concentration in a bar having circular transverse hole, as compared to its static stress without hole will be
Same in both cases
2 times more
3 times more
4 times more
Ball bearing type screws are found in following application
Screw jack
Aeroplane engines
Crane
Steering mechanism
A self locking screw has
Fine threads
Course threads
Coefficient of friction is greater than tangent of load angle
Hole for inserting split pin
When bevel gears connect two shafts whose axes intersect at an angle greater than a right angle and one of the bevel gears has a pitch angle of 90°, then they are known as
Angular bevel gears
Mitre gears
Internal bevel gears
Crown bevel gears
According to Indian standard specifications, 100 H6/g5 means that
Tolerance grade for the hole is 6 and for the shaft is 5
Tolerance grade for the shaft is 6 and for the hole is 5
Tolerance grade for the shaft is 4 to 8 and for the hole is 3 to 7
Tolerance grade for the hole is 4 to 8 and for the shaft is 3 to 7
The ratio of circumferential stress to longitudinal stress in a thin cylinder subjected to an internal pressure is
½
1
2
4
The taper on a rectangular sunk key is
1 in 16
1 in 32
1 in 48
1 in 100
Wahl's stress factor __________ very rapidly as the spring index decreases.
Increases
Decreases
Remain same
None of these
Yield point in fatigue loading as compared to static loading is
Same
Higher
Lower
Depends on other factors
The effective stress in wire ropes during normal working is equal to the stress due to
Axial load plus stress due to bending
Acceleration/retardation of masses plus stress due to bending
Axial load plus stress due to acceleration/retardation
Bending plus stress due to acceleration/retardation
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
The initial tension (in newtons) in a bolt used for making a fluid tight joint like steam engine cover joints, is calculated by the relation (where d = Nominal diameter of bolt in mm)
1420 d
1680 d
2080 d
2840 d
A sliding bearing which operates without any lubricant present, is called
Zero film bearing
Boundary lubricated bearing
Hydrodynamic lubricated bearing
Hydrostatic lubricated bearing
The coefficient of friction in belt drive depends upon
Material of belt
Material of pulley
Materials of belt and pulley
Belt velocity
The valve rod in a steam engine is connected to an eccentric rod by
Cotter joint
Bolted joint
Knuckle joint
Universal coupling
If the size of a standard specimen for a fatigue testing machine is increased, the endurance limit for the material will
Have same value as that of standard specimen
Increase
Decrease
None of these
According to maximum shear stress theory, the maximum shear stress in the shaft is
(1/2) × √(σ² + 4τ²)
√(σ² + 4τ²)
(1/2) × [σ + √(σ² + 4τ²)]
σ + √(σ² + 4τ²)
In a marine flange coupling, the pitch circle diameter of bolts is taken as
1.2 d
1.6 d
2d
2.5 d
The stress induced in the belt is,
Tensile stress
Compressive stress
Direct shear stress
Torsional shear stress