Tensile strength of a mild steel specimen can be roughly predicted from following hardness test
Brinell
Rockwell
Vickers
None of the above
Correct Answer :
A. Brinell
Related Questions
The difference between the tooth space and the tooth thickness as measured on the pitch circle, is called
Working depth
Clearance
Backlash
Face width
The objective of crowning of the flat pulleys of belt drive is to
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 of the following spring is used in mechanical wrist watch?
Helical compression spring
Spiral spring
Torsion spring
Belleville spring
The smallest diameter of an external or internal screw thread is known as
Minor diameter
Major diameter
Pitch diameter
None of these
In a marine flange coupling, the pitch circle diameter of bolts is taken as
1.2 d
1.6 d
2d
2.5 d
When a close coiled helical spring is compressed, its wire is subjected to
Tension
Shear
Compression
All of the above
Lewis form factor for 14 ½° composite and full depth involute system is (where T = Number of teeth)
0.124 - (0.684/T)
0.154 - (0.912/T)
0.175 - (0.841/T)
None of these
A sliding bearing which operates without any lubricant present, is called
Zero film bearing
Boundary lubricated bearing
Hydrodynamic lubricated bearing
Hydrostatic lubricated bearing
The application of third type levers is found in
A pair of tongs
Hand wheel of a punching press
Lever of a loaded safety valve
Handle of a hand pump
Residual stress in materials
Acts when external load is applied
Becomes zero when external load is removed
Is independent of external loads
Is always harmful
When a circular beam of diameter d is subjected to a shear force F, the maximum shear stress induced will be
4F/ πd²
6F/ πd²
8F/ πd²
16F/ 3πd²
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
In order to remove internal stresses produced by hardening the steel, the process usually adopted is
Tempering
Normalising
Annealing
Spheroidising
For general industrial machinery, the ratio of the length of journal to its diameter is taken as
0.5 to 1
1 to 2
3 to 5
5 to 10
Which is positive drive?
Flat belt drive
V-belt drive
Crossed belt drive
Timing belt
According to I.B.R., the distance between the rows of rivets, for equal number of rivets in more than one row for lap joint or butt joint (chain riveting) shall not be less than
d
1.5 d
2d
2.5 d
If a shaft made from ductile material is subjected to combined bending and twisting moment, calculations based on which one of the following failure theories will give the most conservative value?
Maximum principal stress theory
Maximum shear stress theory
Maximum strain energy theory
Maximum distortion energy theory
The permissible stress in the fillet weld is 100 N/mm². The fillet weld has equal leg lengths of 15 mm each. The allowable shearing load on the weldment per cm length of the weld is
7.5 kN
10.6 kN
15 kN
22.5 kN
In testing a material for endurance strength, it is subjected to
Static load
Dynamic load
Impact load
Completely reversed load
Deep groove ball bearings are used for
Heavy thrust load only
Small angular displacement of shafts
Radial load at high speed
Combined thrust and radial loads at high speed
A taper key which fits half in the key way of the hub and half in the key way of shaft, is known as
Angular bevel gears
Mitre gears
Crown Bevel gears
Internal bevel gears
In an oil lubricated journal bearing, the coefficient of friction between the journal and the bearing
Remains constant at all speeds
Is minimum at zero speed and increases monotonically with increase in speed
Is maximum at zero speed and decreases monotonically with increase in speed
Becomes minimum at an optimum speed and then increases with further increase in speed
A key made from a cylindrical disc having segmental cross-section, is known as
Woodruff key
Feather key
Flat saddle key
Gib head key
The square threads are usually found on
Spindles of bench vices
Railway carriage couplings
Feed mechanism of machine tools
Screw cutting lathes
When a belt drive is transmitting maximum power,
Effective tension is equal to centrifugal tension
Effective tension is half of centrifugal tension
Driving tension on slack side is equal to centrifugal tension
Driving tension on tight side is twice the centrifugal tension
Which is correct statement?
A member made of steel will generally be more rigid than a member of equal load carrying ability made of cast iron
A member made of cast iron will generally be more rigid than a member of equal load carrying ability made of steel
Both will be equally rigid
Which one is rigid will depend on several other factors
A hollow saddle key is
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
If a bearing is designated by the number 305, it means that the bearing is of
Medium series whose bore is 5 mm
Medium series whose bore is 25 mm
Light series whose bore is 25 mm
Light series whose bore is 5 mm
Two shafts of the same length and material are joined in series. If the ratio of their diameters is 2, then the ratio of their angles of twist will be
2
4
8
16
In case of pressure vessels having open ends, the fluid pressure induces
Longitudinal stress
Circumferential stress
Shear stress
None of these