A backing ring is used inside the pipe joint when making a
Butt weld
Fillet weld
Sleeve weld
Socket weld
Correct Answer :
A. Butt weld
Related Questions
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
For a square key made of mild steel, the shear and crushing strength are related as
Shear strength is equal to crushing strength
Shear strength is greater than crushing strength
Shear strength is less than crushing strength
None of the above
The tension on the slack side of the belt is __________ the tension on the tight side of the belt.
Equal to
Less than
Greater than
None of these
If a load W is applied instantaneously on a bar; Then the stress induced in bar will
Be independent of ratio of mass of load W to mass of bar (y)
Increase with increase in y
Decrease with decrease in y
Depend on other considerations
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
In a flange coupling, the flanges are coupled together by means of
Bolts and nuts
Studs
Headless taper bolts
None of these
The included angle for the V-belt is usually
10°-20°
30°-40°
40°-60°
60°-80°
The rated life of a bearing varies
Directly as load
Inversely as square of load
Inversely as cube of load
Inversely as fourth power of load
The helix angle for double helical gears may be made up to
45°
60°
75°
90°
When the belt speed increases
Power transmitted increases
Power transmitted decreases
Power transmitted increases to a maximum value and then decreases
Power transmitted remains the same
The pitch diameter is the __________ diameter of an external or internal screw thread.
Effective
Smallest
Largest
None of these
When a closely coiled helical spring is subjected to a couple about its axis, the stress induced in the wire material of the spring is
Bending stress only
A combination of torsional shear stress and bending
Direct shear stress only
A combination of bending stress and direct shear stress
In composite or reverse laid ropes
Direction of twist of wires in strands is opposite to the direction of twist of strands
Direction of twist of wires and strands are same
Wires in two adjacent strands are twisted in opposite direction
Wires are not twisted
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
Three different weights fall from a certain height under vacuum. They will take
Same time to reach earth
Times proportional to weight to reach earth
Times inversely proportional to weight to reach earth
None of the above
In Vickers hardness testing, the pyramid indentor apex is
40°
122°
136°
152°
In hydrostatic bearings
The Oil film pressure is generated only by the rotation of the journal
The oil film is maintained by supplying oil under pressure
Do not require external supply of lubricant
Grease is used for lubrication
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
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 nitrated parts, the origins of the fatigue cracks will occur at
Surface
Just below the surface
Within the core
None of the above
In unilateral system of tolerance, the tolerance is allowed on
Both sides of the actual size
One side of the actual size
One side of the nominal size
Both sides of the nominal size
Which of the following statement is correct for gears?
The pitch circle diameter is equal to the product of module and number of teeth
The addendum is less than dedendum
The pitch circle is always greater than the base circle
All of the above
A self locking screw has
Fine threads
Course threads
Coefficient of friction is greater than tangent of load angle
Hole for inserting split pin
An open belt drive is used when
Shafts are arranged at right angles and rotate in one definite direction
Shafts are arranged parallel and rotate in the opposite directions
Shafts are arranged parallel and rotate in the same directions
Driven shaft is to be started or stopped whenever desired without interfering with the driving shaft
In replacing the V-belts, a complete set of new belts is used instead of replacing a single damaged belt because
Belts are available in sets
Only one belt cannot be fitted with other used belts
The new belt will carry more than its share and result in short life
New and old belts will cause vibrations
In a hydrodynamic lubricated bearing
There is a thick film of lubricant between the journal and the bearing
There is a thin film of lubricant between the journal and the bearing
The lubricant is forced between the journal and the bearing, by external pressure
There is no lubricant between the journal and the bearing
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
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
The material used for brake lining should have __________ coefficient of friction.
Low
High
Moderate
None of these
In order to remove internal stresses produced by hardening the steel, the process usually adopted is
Tempering
Normalising
Annealing
Spheroidising