The initial tension (in newtons) in a bolt used for making a fluid tight joint like steam engine cover joints, is calculated by the relation (where d = Nominal diameter of bolt in mm)
1420 d
1680 d
2080 d
2840 d
Correct Answer :
D. 2840 d
Related Questions
Pick up wrong statement. Fatigue strength can be increased by
Cold working
Shot peening
Grinding and lapping surface
Hot working
Basic shaft is one
Whose upper deviation is zero
Whose lower deviation is zero
Whose lower as well as upper deviations are zero
Does not exist
In static loading, stress concentration is more serious in
Brittle materials
Ductile materials
Brittle as well as ductile materials
Elastic materials
In order to determine the stresses in a thin cylinder due to an internal pressure, it is assumed that
The effect of curvature of the cylinder wall is neglected
The tensile stresses are uniformly distributed over the section of the walls
The effect of the restraining action of the heads at the end of the pressure vessel is neglected
All of the above
The process extensively used for making bolts and nuts is
Hot piercing
Extrusion
Cold peening
Cold heading
The piston rod of a steam engine is usually connected to the crosshead by means of
Bolted joint
Knuckle joint
Cotter joint
Universal joint
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)
The bending stress in a curved beam is
Zero at the centroidal axis
Zero at the point other than centroidal axis
Maximum at the neutral axis
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
The function of cutting oil when threading a pipe is to
Provide cooling action
Lubricate the dies
Help removes chips
All of the above
In Vickers hardness testing, the pyramid indentor apex is
40°
122°
136°
152°
In case of pressure vessels having closed ends, the fluid pressure induces
Longitudinal stress
Shear stress
Circumferential stress
None of these
An imaginary circle which by pure rolling action gives the same motion as the actual gear, is called
Addendum circle
Dedendum circle
Pitch circle
Clearance circle
Two rigid plates are clamped by means of bolt and nut with an initial force F. After tightening, a separating force P (P < F) is applied to the lower plate, which in turn acts on the nut. The tension in the both after this is
F + P
F P
P
F
When a nut is tightened by placing a washer below it, the bolt will be subjected to following type of loads
Compression
Tension
Shear
Combined loads
The centre to centre distance between two consecutive rivets in a row, is called
Margin
Pitch
Back pitch
Diagonal pitch
Which one of the following is a positive drive?
V-belt drive
Rope drive
Crossed flat belt drive
Chain drive
The designation M 33 × 2 of a bolt means
Metric threads of 33 numbers in 2 cm
Metric threads with cross-section of 33 mm
Metric threads of 33 mm outside diameter and 2 mm pitch
Bolt of 33 mm nominal diameter having 2 threads per cm
In a marine flange coupling, the pitch circle diameter of bolts is taken as
1.2 d
1.6 d
2d
2.5 d
A connecting rod should be
Strong in buckling about X-axis
Strong in buckling about Y-axis
Equally strong in buckling about X-axis and Y-axis
Any one of the above
A leaf spring in automobiles is used
To apply forces
To measure forces
To absorb shocks
To store strain energy
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
Stress concentration in static loading is more serious in
Ductile materials
Brittle materials
Equally serious in both cases
Depends on other factors
When a circular beam of diameter d is subjected to a shear force F, the maximum shear stress induced will be
4F/ πd²
6F/ πd²
8F/ πd²
16F/ 3πd²
A hot short metal is
Brittle when cold
Brittle when hot
Brittle under all conditions
Ductile at high temperature
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 order to avoid tearing of the plate at edge, the distance from the center line of the rivet hole to the nearest edge of the plate in terms of dia. of rivet d should be equal to
d
1.25 d
1.5 d
1.75 d
Buttress threads are usually found on
Screw cutting lathes
Feed mechanisms
Spindles of bench vices
Railway carriage couplings
A shaft is subjected to a maximum bending stress of 80 N/mm² and maximum shearing stress equal to 30 N/mm² at a particular section. If the yield point in tension of the material is 280 N/mm² and the maximum shear stress theory of failure is used, then the factor of safety obtained will be
2.5
2.8
3.0
3.5
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