The maximum normal stress theory is used for
Plastic materials
Brittle materials
Non-ferrous materials
Ductile materials
Correct Answer :
B. Brittle materials
Related Questions
Taper usually provided on cotter is
1 in 5
1 in 10
1 in 24
1 in 40
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 hot short metal is
Brittle when cold
Brittle when hot
Brittle under all conditions
Ductile at high temperature
A feather key is generally
Loose in shaft and tight in hub
Tight in shaft and loose in hub
Tight in both shaft and hub
Loose in both shaft and hub
Two shafts of the same length and material are joined in series. If the ratio of their diameters is 2, then the ratio of their angles of twist will be
2
4
8
16
Which one of the following is a positive drive?
V-belt drive
Rope drive
Crossed flat belt drive
Chain drive
The maximum stress due to stress concentration in a bar having circular transverse hole, as compared to its static stress without hole will be
Same in both cases
2 times more
3 times more
4 times more
The load cup of a screw jack is made separate from the head of the spindle to
Prevent the rotation of load being lifted
Enhance the load carrying capacity of the jack
Reduce the effort needed for lifting the working load
Reduce the value of frictional torque
If threads on a bolt are left hand, threads on nut will be
Right hand with same pitch
Left hand with same pitch
Could be left or right hand
Right hand with fine pitch
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
A compound cylinder with inner radius 50 mm and outer radius 70 mm is made by shrinking one cylinder on to the other cylinder, the junction radius is 60 mm and the junction pressure is 1.1 N/mm². The maximum hoop stress developed in the inner cylinder is
3.6 N/mm² compression
3.6 N/mm² tension
7.2 N/mm² compression
7.2 N/mm² tension
The usual clearance provided in hydrodynamic bearing per mm of diameter of shaft is
0.01 micron
0.1 micron
1 micron
10 microns
The process which improves the machinability of steels, but lowers the hardness and tensile strength is
Normalising
Full annealing
Process annealing
Spheroidising
Which process will increase the fatigue duration of parts?
Finishing and polishing
Shotpeening
De-carburisation
Electroplating
A tapered key which fits in a key way in the hub and the bottom of which is shaped to fit the curved surface of the shaft, is known as,
Hollow saddle key
Hollow key
Soft key
None of these
The objective of crowning of the flat pulleys of belt drive is to
Prevent the belt from running off the pulley
Increase the power transmission capacity
Increase the belt velocity
Prevent the belt joint from damaging the belt surface
The stress which vary from a minimum value to a maximum value of the same nature (i.e. tensile or compressive) is called
Repeated stress
Yield stress
Fluctuating stress
Alternating stress
The edges of a boiler plate are bevelled to an angle of
30°
45°
60°
80°
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 V-belt drive, belt touches
At bottom
At sides only
Both at bottom and sides
Could touch anywhere
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
Oil in journal bearing should be applied at the point where load is
Nil or lightest
Maximum
Average
Any one of the above
Yield point in fatigue loading as compared to static loading is
Same
Higher
Lower
Depends on other factors
In unilateral system of tolerance, the tolerance is allowed on
Both sides of the actual size
One side of the actual size
One side of the nominal size
Both sides of the nominal size
A metal pipe of 1 m diameter contains a fluid having a pressure of 1 N/mm². If the permissible tensile stress in the metal is 20 N/mm², then the thickness of the metal required for making the pipe will be
5 mm
10 mm
15 mm
25 mm
The pitch of threads on a Jock nut in comparison to pitch of nut is
Same
Coarser
Finer
Very fine
If a bearing is designated by the number 305, it means that the bearing is of
Medium series whose bore is 5 mm
Medium series whose bore is 25 mm
Light series whose bore is 25 mm
Light series whose bore is 5 mm
According to Unwin's formula, the relation between the diameter of rivet hole (d) and the thickness of plate (t) is given by (where d and t are in mm)
d = t
d = 1.6 t
d = 2t
d = 6t
A spring is used to
Measure forces
Apply forces
Store energy
All of these
The bearings of medium series have capacity __________ over the light series.
10 to 20 %
20 to 30 %
30 to 40 %
40 to 50 %