A self locking screw has
Fine threads
Course threads
Coefficient of friction is greater than tangent of load angle
Hole for inserting split pin
Correct Answer :
C. Coefficient of friction is greater than tangent of load angle
Related Questions
The cold working of metals is carried out __________ the recrystallisation temperature.
Above
Below
At
None of these
A steel containing __________ 0.8% carbon is known as hypoeutectoid steel.
Equal to
Less than
Greater than
None 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)
A connecting rod should be
Strong in buckling about X-axis
Strong in buckling about Y-axis
Equally strong in buckling about X-axis and Y-axis
Any one of the above
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
For a bevel gear having the pitch angle θ, the ratio of formative number of teeth (TE) to actual number of teeth (T) is
1/sinθ
1/cosθ
1/tanθ
sinθ cosθ
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 constant factor in case of R10 series of preferred numbers is
1.06
1.12
1.26
1.58
A tapered key which fits in a key way in the hub and the bottom of which is shaped to fit the curved surface of the shaft, is known as,
Hollow saddle key
Hollow key
Soft key
None of these
In nitrated parts, the origins of the fatigue cracks will occur at
Surface
Just below the surface
Within the core
None of the above
The metal suitable for bearings subjected to heavy loads is
White metal
Silicon bronze
Monel metal
Phosphor bronze
Ball bearing type screws are found in following application
Screw jack
Aeroplane engines
Crane
Steering mechanism
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
A metal pipe of 1 m diameter contains a fluid having a pressure of 1 N/mm². If the permissible tensile stress in the metal is 20 N/mm², then the thickness of the metal required for making the pipe will be
5 mm
10 mm
15 mm
25 mm
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
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
Soderberg relation is based on __________ of the material whereas all other failure relation for dynamic loading are based on ultimate strength of the material.
Elastic strength
Yield strength
Shear strength
None of these
Fibrous fracture occurs in
Ductile material
Brittle material
Elastic material
Hard material
In worm, gears, pitch lead angle is
Half the angle between two inclined faces in axial plane
The angle between the tangent to the pitch helix and the plane of rotation
The angle between the tangent to the pitch helix and an element of the cylinder
None of the above
The wire ropes make contact at
Bottom of groove of the pulley
Sides and bottom of groove of the pulley
Anywhere in the groove of the pulley
Sides of groove of the pulley
A localised compressive stress at the area of contact between two members is known as
Tensile stress
Bending stress
Bearing stress
Shear stress
Which of the following coupling is used to connect two shafts which have both lateral and angular misalignment?
Bushed pin type coupling
Universal coupling
Oldham coupling
All of these
For a shoe brake, the equivalent coefficient of friction is equal to (where μ = Actual coefficient of friction, and θ = Semi-block angle)
2μ sinθ/(θ + sinθ)
μ sinθ/(2θ + sin 2θ)
4μ sinθ/(θ + sinθ)
4μ sinθ/(2θ + sin 2θ)
If two springs are in parallel then their overall stiffness will be
Half
Same
Double
None of the above
When two non-parallel or intersecting but coplanar shafts are connected by gears, the arrangement is known as,
Bevel gearing
Helical gearing
Worm gearing
None of these
A coupling used to connect two perfectly aligned shafts, is
Muff coupling
Compression coupling
Flange coupling
All of these
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
Taper on the cotter and slot is provided
On both the sides
On one side only
On none of the sides
May be provided anywhere
In order to determine the stresses in a thin cylinder due to an internal pressure, it is assumed that
The effect of curvature of the cylinder wall is neglected
The tensile stresses are uniformly distributed over the section of the walls
The effect of the restraining action of the heads at the end of the pressure vessel is neglected
All of the above
A thin spherical shell of internal diameter d is subjected to an internal pressure p. If V is the storage capacity of shell, then its diameter will be
(6V/ π)1/2
(6V/ π)1/3
(6V/ π)2
(6V/ π)3