An alien bolt is
Self locking bolt
Same as stud
Provided with hexagonal depression in head
Used in high speed components
Correct Answer :
C. Provided with hexagonal depression in head
Related Questions
When the length of the journal is equal to the diameter of the journal, then the bearing is said to be a
Short bearing
Long bearing
Medium bearing
Square bearing
Wahl's stress factor __________ very rapidly as the spring index decreases.
Increases
Decreases
Remain same
None of these
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
The function of cutting oil when threading a pipe is to
Provide cooling action
Lubricate the dies
Help removes chips
All of the above
Which of the following statement is wrong?
A key is used as a temporary fastening
A key is subjected to tensile stresses
A key is always inserted parallel to the axis of the shaft
A key prevents relative motion between the shaft and boss of the pulley
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
Which of the following is a permanent fastening?
Bolts
Keys
Cotters
Rivets
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
Crown bevel gears
Angular bevel gears
Mitre gears
Internal bevel gears
The power transmitted by belt drive depends upon
Belt velocity
Initial belt tension
Arc of contact
All of the above
A connecting rod subjected to an axial load may buckle with
X-axis as neutral axis
Y-axis as neutral axis
X-axis or Y-axis as neutral axis
Z-axis
If P1 and P2 are the tight and slack side tensions in the belt, then the initial tension Pi (neglecting centrifugal tension) will be equal to
P1 - P2
P1 + P2
2 × (P1 + P2)
[2 × (P1 + P2)] + Pc Where Pc is centrifugal tension
A compound cylinder with inner radius 50 mm and outer radius 70 mm is made by shrinking one cylinder on to the other cylinder, the junction radius is 60 mm and the junction pressure is 1.1 N/mm². The maximum hoop stress developed in the inner cylinder is
3.6 N/mm² compression
3.6 N/mm² tension
7.2 N/mm² compression
7.2 N/mm² tension
The fatigue stress concentration factor is defined as
The ratio of endurance limit with stress concentration to the endurance limit without stress concentration
The ratio of endurance limit without stress concentration to the endurance limit with stress concentration
The product of the endurance limits with and without stress concentration
All of the above
Which of the following statement is wrong?
The V-belt may be operated in either direction with tight side of the belt at the top or bottom
The V-belt drive is used with large centre distance
The power transmitted by V-belts is less than flat belts for the same coefficient of friction, arc of contact and allowable tension in the belts
The ratio of driving tensions in V-belt drive is more than flat belt drives
Crowning on pulley helps
In decreasing the slip of the belt
In increasing the slip of the belt
To keep the belt in centre on a pulley while it is in motion
To increase pulley life
Slenderness ratio is the ratio of
Effective length of column to least radius of gyration of the column
Width of column to depth of column
Maximum size of column to minimum size of column
Effective length of column to width of column
Allen bolts are
Self locking bolts
Designed for shock load
Used in aircraft application
Provided with hexagonal depression in head
The ratio of endurance limit in shear to the endurance limit in flexure is
0.33
0.4
0.5
0.55
The material generally used for aircraft components is
Mild steel
High speed steel
Stainless steel
Aluminium
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
In Vickers hardness testing, the pyramid indentor apex is
40°
122°
136°
152°
The application of third type levers is found in
Handle of a hand pump
Hand wheel of a punching press
Lever of a loaded safety valve
A pair of tongs
A bolt of uniform strength can be developed by
Keeping the core diameter of threads equal to the diameter of unthreaded portion of the bolt
Keeping the core diameter smaller than the diameter of the unthreaded portion
Keeping the nominal diameter of threads equal to the diameter of unthreaded portion of the bolt
None of the above
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
The stiffness of a closely coiled helical spring subjected to an axial load W is equal to (where G = Modulus of rigidity, and n = Number of active coils)
Gd⁴/ 8D3n
Gd3/ 8D3n
Gd⁴/ 4D3n
Gd⁴/ 8D²n
For unequal width of butt straps, the thicknesses of butt straps are
0.75 t for narrow strap on the inside and 0.625 t for wide strap on the outside
0.75 t for wide strap on the inside and 0.625 t for narrow strap on the outside
0.75 t for both the straps on the inside and outside
0.625 t for both the straps on the inside and outside
In a boundary lubricated bearing, there is a __________ of lubricant between the journal and the bearing.
Thick film
Thin film
Either A or B
None of these
Which of the following statement is correct regarding power screws?
The efficiency of a self locking screw can not be more than 50%
The efficiency of Acme (trapezoidal) thread is less than that of a square thread
If the friction angle is less than the helix angle of the screw, then the efficiency will be more than 50%
(A) and (B) Only
Tearing resistance required to tear off the plate per pitch length is (where p = Pitch of rivets, d = Dia. of rivet hole, and σt = Permissible tensile stress for plate material)
p.d.σt
p.t.σt
(p - d) σt
(p - d) t.σt
When the bearing is subjected to large fluctuations of load and heavy impacts, the bearing characteristic number should be _________ the bearing modulus.
10 times
5 times
15 times
20 times