In the calculation of induced shear stress in helical springs, the Wahl's stress factor is used to take care of
Combined effect of transverse shear stress and bending stress in the wire
Combined effect of bending stress and curvature of the wire
Combined effect of transverse shear stress and curvature of wire
Combined effect of torsional shear stress and transverse shear stress in the wire
Correct Answer :
B. Combined effect of bending stress and curvature of the wire
Related Questions
A localised compressive stress at the area of contact between two members is known as
Tensile stress
Bending stress
Bearing stress
Shear stress
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
When the connected members are very yielding (soft gasket) as compared to the bolt, then the resultant load on the bolt will be equal to the
Initial tension
External load applied
Sum of the initial tension and external load applied
Initial tension or external load, whichever is greater
A leaf spring in automobiles is used
To apply forces
To measure forces
To absorb shocks
To store strain energy
The helix angle for double helical gears may be made up to
45°
60°
75°
90°
A locking device in which the bottom cylindrical portion is recessed to receive the tip of the locking set screw, is called
Ring nut
Castle nut
Sawn nut
Jam nut
Idler pulley is used for
Increasing velocity ratio
For applying tension
Changing the direction of motion of belt
All of these
According to I.B.R., the efficiency of a triple riveted butt joint with double straps of unequal width (5 rivets per pitch length) should be
45 to 60 %
63 to 70 %
70 to 83 %
80 to 90 %
Creep in belt is due to
Material of the belt
Material of the pulley
Uneven extensions and contractions due to varying tension
All of the above
Stress concentration is caused due to
Variations in load acting on a member
Variations in properties of materials in a member
Abrupt change of cross-section
All of these
The ratio of endurance limit in shear to the endurance limit in flexure is
0.33
0.4
0.5
0.55
If a spring is cut down into two springs, the stiffness of cut springs will be
Half
Same
Double
None of the above
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
The edges of a boiler plate are bevelled to an angle of
30°
45°
60°
80°
Silver based solder is used for
Flaring
Brazing
Soft soldering
Fusion welding
Spring index is
Ratio of coil diameter to wire diameter
Load required to produce unit deflection
Its capability of storing energy
Indication of quality of spring
If an application calls for stresses on screw threads in one direction only, then the following type of thread would be best suited
Square
Acme
Buttress
BSW
In designing a connecting rod, it is considered like __________ for buckling about X-axis.
Both ends hinged
Both ends fixed
One end fixed and the other end hinged
One end fixed and the other end free
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
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 endurance or fatigue limit is defined as the maximum value of the stress which a polished standard specimen can withstand without failure, for infinite number of cycles, when subjected to
Static load
Dynamic load
Static as well as dynamic load
Completely reversed load
A V-belt designated as B 4430 LP has
4430 mm as diameter of small pulley
4430 mm as nominal pitch length
4430 mm as diameter of large pulley
4430 mm as centre distance between pulleys
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
The efficiency of a riveted joint is equal to
Pt /P
Ps /P
Pc /P
Least of Pt, Ps and Pc/P
Castle nut is a locking device in which
One smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly is middle of nut and then slot reduced by tightening a screw
A hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin spitted and bent in reverse direction at other end
The centre distance between two meshing involute gears is equal to
(Sum of base circle radii)/cosφ
(Difference of base circle radii)/cosφ
(Sum of pitch circle radii)/cosφ
(Difference of pitch circle radii)/cosφ
The property of a material which enables it to resist fracture due to high impact loads is known as
Elasticity
Endurance
Strength
Toughness
According to Indian standards, the diameter of rivet hole is made larger than the basic size of rivet by
0.5 mm upto rivet diameter of 24 mm
1 mm for rivet diameter from 27 mm to 36 mm
2 mm for rivet diameter from 39 mm to 48 mm
All of the above
Stress concentration is caused due to
Variation in properties of material from point to point in a member
Pitting at points or areas at which loads on a member are applied
Abrupt change of section
All of the above
A column is known as a long column if the slenderness ratio is
40
50
70
100