According to I.B.R., when the thickness of boiler shell (t) is greater than 8 mm, then the diameter of rivet hole (d) is obtained by
Equating tearing resistance of the plate to the shearing resistance of the rivets
Equating tearing resistance of the plate to the crushing resistance of the rivets
Equating shearing resistance to the crushing resistance of the rivets
None of the above
Correct Answer :
B. Equating tearing resistance of the plate to the crushing resistance of the rivets
Related Questions
When two helical springs of equal lengths are arranged to form a cluster spring, then
Shear stress in each spring will be equal
Load taken by each spring will be half the total load
Only A is correct
Both A and B is correct
Crushing resistance required to crush the rivet per pitch length is
p.d.σc
p.t.σc
n.d.t.σc
(p - d) t.σc
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
The shear stress in a beam varies from zero at the outer fibres to a maximum at the________.
Neutral surface
Upper surface
Lower surface
None of these
When the screw in a mechanical screw jack rotates, the load kept on the top of it moves
Axially upwards
Axially downwards
Axially upwards or downwards
None of these
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
The included angle in unified of American National threads is
60°
55°
47°
29°
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
Eye bolts are used for
Foundation purposes
Absorbing shock and vibrations
Transmission of power
Lifting and transportation of machines and cubicles
The ratio of driving tensions for flat belts, neglecting centrifugal tension, is (where T₁, and T₂ = Tensions on the tight and slack sides of belt respectively, μ = Coefficient of friction, between the belt and pulley, and θ = Angle of contact)
T₁/T₂ = μθ
log (T₁/T₂) = μθ
T₁/T₂ =eμθ
T₁/T₂ = log μθ
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
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
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 effective stress in wire ropes during normal working is equal to the stress due to
Axial load plus stress due to bending
Acceleration/retardation of masses plus stress due to bending
Axial load plus stress due to acceleration/retardation
Bending plus stress due to acceleration/retardation
Belt slip may occur due to
Heavy load
Loose belt
Driving pulley too small
All of the above
For a shaft diameter of 100 mm, the number of bolts in a flange coupling should be
4
6
8
10
Which of the following has threads at both ends?
Bolt
Tap bolt
Stud
None of these
In skew bevel gearing, the axes of shafts are
Intersecting and the teeth are curved
Non-intersecting and nonparallel and the teeth are curved
Non-intersecting and non-parallel and the teeth are straight
None of the above
A universal coupling is used to connect two shafts
Which are not in exact alignment
Which are perfectly aligned
Whose axes intersect at a small angle
Have lateral misalignment
A localised compressive stress at the area of contact between two members is known as
Bending stress
Shear stress
Tensile stress
Bearing stress
The shear stress at a point in a shaft subjected to a torque is
Directly proportional to the polar moment of inertia and to the distance of the point from the axis
Directly proportional to the applied torque and inversely proportional to the polar moment of inertia
Directly proportional to the applied torque and the polar moment of inertia
Inversely proportional to the applied torque and the polar moment of inertia
Taper on the cotter and slot is provided
On both the sides
On one side only
On none of the sides
May be provided anywhere
The ratio of driving tensions in V-belt drives is __________ flat belt drives.
Equal to
sinα times more than
sinα times less than
cosecα times more than
A special case of ductility which permits materials to be rolled or hammered into thin sheets, is called
Plasticity
Elasticity
Ductility
Malleability
According to I.B.R., when the thickness of boiler shell (t) is greater than 8 mm, then the diameter of rivet hole (d) is obtained by
Equating tearing resistance of the plate to the shearing resistance of the rivets
Equating tearing resistance of the plate to the crushing resistance of the rivets
Equating shearing resistance to the crushing resistance of the rivets
None of the above
A bolt of M 24 × 2 means that
The pitch of the thread is 24 mm and depth is 2 mm
Cross-sectional area of the threads is 24 mm²
The nominal diameter of bolt is 24 mm and pitch is 2 mm
The effective diameter of bolt is 24 mm and there are 2 threads per cm
Which of the following screw thread is adopted for power transmission in either direction?
Acme threads
Square threads
Buttress threads
Multiple threads
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 value of stress concentration factor depends upon
Material and geometry of the part
Geometry of the part
Material of the part
None of these
The taper on key is given on
Bottom side only
Top side only
On both sides
Any side