Factor of safety for fatigue loading is the ratio of
Elastic limit to the working stress
Elastic limit to the yield point
Endurance limit to the working stress
Young's modulus to the ultimate tensile strength
Correct Answer :
C. Endurance limit to the working stress
Related Questions
When a beam of rectangular cross-section of width b and depth d, is subjected to a shear force F, the maximum shear stress induced will be
F/bh
3F/2bh
2F/bh
4F/bh
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 creep in the belt is due to
Effect of temperature on belt
Material of belt
Unequal extensions in the belt due to tight and slack side tensions
Stresses beyond elastic limit of belt material
In oilness 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 required to be applied after some intervals
Yield point in fatigue loading as compared to static loading is
Same
Higher
Lower
Depends on other factors
The maximum normal stress theory is used for
Plastic materials
Brittle materials
Non-ferrous materials
Ductile materials
According to I.B.R., the efficiency of a double riveted butt joint with double cover straps of equal width should be
45 to 60 %
63 to 70 %
70 to 83 %
80 to 90 %
The objective of idler pulley in belt drive is to
Decrease the tendency of belt to slip
Increase the power transmission capacity
Increase the wrap angle and belt tension
All the above objectives
In Vickers hardness testing, the pyramid indentor apex is
40°
122°
136°
152°
An open coiled helical compression spring 'A' of mean diameter 50 mm is subjected to an axial load W. Another spring 'B' of mean diameter 25 mm is similar to spring 'A' in all respects. The deflection of spring 'B' will be __________ as compared to spring 'A'.
One-eighth
One-fourth
One-half
Double
The expression 0.175 - 0.841/T is the Lewis form factor for
14 ½° composite and full depth involute system
20° full depth involute system
20° stub system
None of the above
In helical gears, the distance parallel to the axis, between similar faces of adjacent teeth, is called
Normal pitch
Axial pitch
Diametral pitch
Module
The metal suitable for bearings subjected to heavy loads is
White metal
Silicon bronze
Monel metal
Phosphor bronze
The included angle for the V-belt is usually
10°-20°
30°-40°
40°-60°
60°-80°
A column of length l is fixed at both ends. The equivalent length of the column is
l/2
l/√2
l
2 l
The material used for brake lining should have __________ coefficient of friction.
Low
High
Moderate
None of these
The coefficient of friction in belt drive depends upon
Material of belt
Material of pulley
Materials of belt and pulley
Belt velocity
According to Indian standard specifications, 100 H6/g5 means that
Tolerance grade for the hole is 6 and for the shaft is 5
Tolerance grade for the shaft is 6 and for the hole is 5
Tolerance grade for the shaft is 4 to 8 and for the hole is 3 to 7
Tolerance grade for the hole is 4 to 8 and for the shaft is 3 to 7
In designing thick cylinders, the equation used is
Lame's equation
Birnie's equation
Clavarinos' equation
All 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
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 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
When the fulcrum is in between the load and effort, the lever is said to be of
First type
Second type
Third type
Any one of these
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)
In helical gears, the right hand helixes on one gear will mesh __________ helixes on the other gear.
Right hand
Left hand
Both A and B
None of these
The smallest diameter of an external or internal screw thread is known as
Minor diameter
Major diameter
Pitch diameter
None of these
The power transmitted by the belt drive can be increased by
Increasing the initial tension in the belt
Dressing the belt to increase the coefficient of friction
Increasing wrap angle by using idler pulley
All of the above methods
The notch angle of the Izod impact test specimen is
10°
20°
30°
45°
The lower deviation is the algebraic difference between the
Actual size and the corresponding basic size
Maximum limit and the basic size
Minimum limit and the basic size
None of the above
Which of the following statement is correct?
The distance from a point on one thread to the corresponding point on the next thread is called pitch
The distance which a screw thread advances axially in one rotation of the nut is called lead
In single start threads, lead is equal to pitch
All of the above