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
Correct Answer :
C. Lap joint with one ring overlapping the other
Related Questions
In testing a material for endurance strength, it is subjected to
Static load
Dynamic load
Impact load
Completely reversed load
In order to have a connecting rod equally strong in buckling about X-axis and Y-axis, the moment of inertia about X-axis should be __________ the moment of inertia about Y-axis.
Equal to
Twice
Three times
Four times
If two springs are in parallel then their overall stiffness will be
Half
Same
Double
None of the above
Shear stress theory is applicable for
Ductile materials
Brittle materials
Elastic materials
All of the above
In a butt welded joint, the size of weld is __________ the throat of weld.
0.5 times
Equal to
2 times
Double
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
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 circumferential and longitudinal strains in a cylindrical boiler under internal steam pressure are εc and εl respectively. The change in volume of the boiler cylinder per unit volume will be
εc + 2εl
2εc + εl
εc + εl²
εc² + εl
A steel containing 0.8% carbon is known as
Eutectoid steel
Hypereutectoid steel
Hypo-eutectoid steel
None of these
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
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
Stress concentration in static loading is more serious in
Ductile materials
Brittle materials
Equally serious in both cases
Depends on other factors
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
In a multiple V-belt drive, if one of the belts break, then
Only the broken belt is replaced
The entire set of belts is replaced
The broken belt and the belt on either side of it, is replaced
The broken belt need not to be replaced
Form coefficient of spring is
Ratio of coil diameter to wire diameter
Load required to produce unit deflection
Its capability of storing energy
Concerned with strength of wire of spring
In block brakes, the ratio of shoe width to wheel diameter is taken between
0.1 and 0.25
0.25 and 0.50
0.50 and 0.75
0.75 and 1
Gear box is used
To produce torque
For speed reduction
To obtain variable speeds
To increase efficiency of system
Transverse fillet welded joints are designed for
Tensile strength
Compressive strength
Shear strength
Bending strength
The value of stress concentration factor depends upon
Material and geometry of the part
Geometry of the part
Material of the part
None of these
According to Indian standard specifications, a grey cast iron designated by 'FG 200' means that the
Carbon content is 2%
Maximum compressive strength is 200 N/mm²
Minimum tensile strength is 200 N/mm²
Maximum shear strength is 200 N/mm²
If the size of a standard specimen for a fatigue testing machine is increased, the endurance limit for the material will
Have same value as that of standard specimen
Increase
Decrease
None of these
Cast iron pipes are mainly used
For conveying steam
In water and sewage systems
In pressure lubrication systems on prime movers
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 stress in the threaded part of the bolt will be __________ as compared to the shank.
Same
Higher
Lower
None of these
If T is the actual number of teeth on a helical gear and φ is the helix angle for the teeth, then formative number of teeth is written as
T sec3φ
T sec²φ
T/sec3φ
T cosecφ
When carbon in the cast iron is principally in the form of graphite, the cast iron will be of
Brown colour
Yellow colour
White colour
Grey colour
The expansion joint is mostly used for pipes which carry steam at __________ pressures.
Low
High
Medium
None of these
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
The fatigue life of a part can be improved by
Electroplating
Polishing
Coating
Shot peening
For standard coarse threads of nut, the threads will be as strong in failure by shear as the bolt in tension, if the height of nut (h) is approximately
0.4 times
0.6 times
0.7 times
0.8 times