In Vickers hardness testing, the pyramid indentor apex is
40°
122°
136°
152°
Correct Answer :
C. 136°
Related Questions
For circumferential joint in boilers, the type of joint used is
Butt joint with single cover plate
Butt joint with double cover plate
Lap joint with one ring overlapping the other
Any one of the above
When a bolt is subjected to shock loading, the resilience of the bolt should be considered in order to prevent breakage at the
Thread
Middle
Shank
Head
A bolt
Has a head on one end and a nut fitted to the other
Has head at one end and other end fits into a tapped hole in the other part to be joined
Has both the ends threaded
Is provided with pointed threads
The temperature at which the new grains are formed in the metal is known as
Lower critical temperature
Upper critical temperature
Recrystallisation temperature
None of these
Gear box is used
To produce torque
For speed reduction
To obtain variable speeds
To increase efficiency of system
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
In a steam engine, the piston rod is usually connected to the crosshead by means of a
Knuckle joint
Cotter joint
Oldham coupling
Universal joint
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 bending moment M and a torque T is applied on a solid circular shaft. If the maximum bending stress equals to maximum shear stress developed, then M is equal to
T/2
T
2T
4T
Which of the following pipe joints would be suitable for pipes carrying steam?
Flanged
Threaded
Bell and spigot
Expansion
In the assembly of pulley, key and shaft
Pulley is made the weakest
Key is made the weakest
Key is made the strongest
All the three are designed for equal strength
The condition for maximum power transmission is that the maximum tension in the flat belt should be equal to
3 Pc
Pc
Pc/3
2 Pc Where, Pc = tension in belt due to centrifugal force
The plasticity is the property of a material which enables it to
Regain its original shape after deformation when the external forces are removed
Draw into wires by the application of a tensile force
Resist fracture due to high impact loads
Retain deformation produced under load permanently
The velocity of sliding ________ the distance of the point of contact from the pitch point.
Is directly proportional to
Is inversely proportional to
Is equal to cos φ multiplied by
Does not depend upon
Wahl's stress factor __________ very rapidly as the spring index decreases.
Increases
Decreases
Remain same
None of these
The shock resistance of steel is increased by adding
Nickel
Chromium
Nickel and chromium
Cobalt and molybdenum
The coefficient of friction in belt drive depends upon
Material of belt
Material of pulley
Materials of belt and pulley
Belt velocity
The dedendum circle diameter is equal to (where φ = Pressure angle)
Pitch circle diameter × cosφ
Addendum circle diameter × cosφ
Clearance circle diameter × cosφ
Pitch circle diameter × sinφ
The pitch diameter is the __________ diameter of an external or internal screw thread.
Effective
Smallest
Largest
None of these
Oil in journal bearing should be applied at the point where load is
Nil or lightest
Maximum
Average
Any one of the above
The lower deviation is the algebraic difference between the
Actual size and the corresponding basic size
Maximum limit and the basic size
Minimum limit and the basic size
None of the above
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)
Jam nut is a locking device in which
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
The centre distance between two meshing involute gears is equal to
(Sum of base circle radii)/cosφ
(Difference of base circle radii)/cosφ
(Sum of pitch circle radii)/cosφ
(Difference of pitch circle radii)/cosφ
Elastic nut is a locking device in which
One small 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
Hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is stewed 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 other end
A sliding bearing in which although lubricant is present, the working surfaces __________ contact each other at least part of the time, is called boundary lubricated bearing.
Partially
Fully
Either A or B
None of these
A locking device in which the bottom cylindrical portion is recessed to receive the tip of the locking set screw, is called
Ring nut
Castle nut
Sawn nut
Jam nut
The load cup of a screw jack is made separate from the head of the spindle to
Prevent the rotation of load being lifted
Enhance the load carrying capacity of the jack
Reduce the effort needed for lifting the working load
Reduce the value of frictional torque
A steel containing __________ 0.8% carbon is known as hypoeutectoid steel.
Equal to
Less than
Greater than
None of these
The notch sensitivity q is expressed in terms of fatigue stress concentration factor Kf and theoretical stress concentration factor Kt as
(Kf + 1)/ (Kt + 1)
(Kf - 1)/ (Kt - 1)
(Kt + 1)/ (Kf + 1)
(Kt - 1)/ (Kf - 1)