Which of the following pipe joints would be suitable for pipes carrying steam?
Flanged
Threaded
Bell and spigot
Expansion
Correct Answer :
D. Expansion
Related Questions
When the belt is transmitting maximum power, the belt speed should be
√(Pmax / 2m)
√(Pmax / 3m)
√(Pmax / m)
√(3m /Pmax) Where m = mass of belt per metre (kg/m) Pmax = maximum permissible tension in belt (N)
If a material fails below its yield point, failure would be due to
Straining
Fatigue
Creep
Sudden loading
Which of the following cotter joint will be used to connect strap end of a connecting rod?
Spigot and socket cotter joint
Sleeve and cotter joint
Gib and cotter joint
Any one of these
The taper on key is given on
Bottom side only
Top side only
On both sides
Any side
In worm gears, the pressure angle is ________ the angle between two inclined faces in axial plane.
Half
Twice
Thrice
None of these
Machine 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 two parts
Similar to stud
If d is the normal diameter of a bolt in mm, then the initial tension in kg in a bolt used for making a fluid tight joint as for steam engine cover joint is calculated by the relation
124 d
138 d
151 d
168 d
Which of the following formula is used in designing a connecting rod?
Euler's formula
Rankine's formula
Johnson's straight line formula
Johnson's parabolic formula
The temperature required for full annealing in hypereutectoid steel is
50°C above upper critical temperature
50°C below upper critical temperature
50°C above lower critical temperature
50°C below lower critical temperature
In the case of an elastic bar fixed at upper end and loaded by a falling weight at lower end, the shock load produced can be decreased by
Decreasing the cross-section area of bar
Increasing the cross-section area of bar
Remain unaffected with cross-section area
Would depend upon other factors
In designing a key, it is assumed that the distribution of forces along the length of key
Varies linearly
Is uniform throughout
Varies exponentially, being more at the torque-input end
Varies exponentially, being less at the torque-input end
The velocity factor for precision metallic gears cut with high accuracy and operating at velocities upto 20 m/s is equal to
0.75/ (0.75 + √v)
3/ (3 + v)
4.5/ (4.5 + v)
6/ (6 + v)
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
The number of slots in a 25 mm castle nut is
8
6
4
2
Oil in journal bearing should be applied at the point where load is
Nil or lightest
Maximum
Average
Any one of the above
The design of shafts made of brittle materials is based on
Guest's theory
Rankine's theory
St Venant's theory
Von Mises theory
When a hole of diameter d is punched in a metal of thickness 't', then the force required to punch a hole is equal to (where τu = Ultimate shear strength of the material of the plate)
d.t.τu
πd.t.τu
π/4 × d².τu
π/4 × d² × t.τu
The contact ratio is the ratio of
Length of arc of recess to the circular pitch
Length of path of contact to the circular pitch
Length of arc of contact to the circular pitch
Length of arc of approach to the circular pitch
If shearing stress in nut is half the tensile stress in a bolt, then nut length should be equal to
Diameter of bolt
0.75 × diameter of bolt
1.25 × diameter of bolt
1.5 × diameter of bolt
Which of the following material has the maximum ductility?
Copper
Mild steel
Aluminium
Zinc
The product of the diametral pitch and circular pitch is equal to
1
1/π
π
π × number of teeth
A screw is said to be over hauling screw, if its efficiency is
More than 50 %
Less than 50 %
Equal to 50 %
None of these
The endurance limit in shear of carbon steel can be obtained by multiplying the endurance limit in flexure by a factor of
0.45
0.55
0.65
0.75
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
The cam follower extensively used in aircraft engines is
Knife edge follower
Flat faced follower
Spherical faced follower
Roller follower
A plate with an elliptical hole in the centre, with semi-major axis (A) perpendicular to the direction of loading and semi-minor axis (b) along the direction of loading, is subjected to a pull P. The maximum stress induced at the edge of the hole is equal to (where σ = Stress for a plate with no hole i.e. nominal stress)
σ [1 + (b/2a)]
σ [1 + (2a/b)]
σ [1 + (b/3a)]
σ [1 + (3a/b)]
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
The process which improves the machinability of steels, but lowers the hardness and tensile strength is
Normalising
Full annealing
Process annealing
Spheroidising
The velocity factor for ordinary cut gears operating at velocities upto 12.5 m/s is equal to
0.75/ (0.75 + √v)
3/ (3 + v)
4.5/ (4.5 + v)
6/ (6 + v)
A self locking screw has
Fine threads
Course threads
Coefficient of friction is greater than tangent of load angle
Hole for inserting split pin