Maximum principal stress theory is applicable for
Ductile materials
Brittle materials
Elastic materials
All of the above
Correct Answer :
B. Brittle materials
Related Questions
When the belt is transmitting maximum power, the belt speed should be
√(Pmax / 2m)
√(Pmax / 3m)
√(Pmax / m)
√(3m /Pmax) Where m = mass of belt per metre (kg/m) Pmax = maximum permissible tension in belt (N)
When bevel gears having equal teeth and equal pitch angles connect two shafts whose axes intersect at right angle, then they are known as
Angular bevel gears
Crown bevel gears
Internal bevel gears
Mitre gears
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
A double fillet welded joint with parallel fillet weld of length l and leg s is subjected to a tensile force P. Assuming uniform stress distribution, the shear stress in the weld is given by
√2P/s.l
P/2.s.l
P/√2.s.l
2P/s.l
Rankine Gordon formula for buckling is valid for
Long column
Short column
Short and long column
Very long column
The gears are termed as medium velocity gears, if their peripheral velocity is
1-3 m/s
3-15 m/s
15-30 m/s
30-50 m/s
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
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
Set screws are
Similar to small size tap bolts except that a greater variety of shapes of heads are available
Slotted for a screw driver and generally used with a nut
Used to prevent relative motion between parts
Similar to stud
The expansion joint is mostly used for pipes which carry steam at __________ pressures.
Low
High
Medium
None of these
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
The maximum shear stress theory is used for
Brittle materials
Ductile materials
Plastic materials
Nonferrous materials
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
In a multiple V-belt drive, if one of the belts break, then
Only the broken belt is replaced
The entire set of belts is replaced
The broken belt and the belt on either side of it, is replaced
The broken belt need not to be replaced
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)
In a steam engine, the piston rod is usually connected to the crosshead by means of a
Knuckle joint
Cotter joint
Oldham coupling
Universal joint
The bearings of medium series have capacity __________ over the light series.
10 to 20 %
20 to 30 %
30 to 40 %
40 to 50 %
The taper on a rectangular sunk key is
1 in 16
1 in 32
1 in 48
1 in 100
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 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 the assembly of pulley, key and shaft
Pulley is made the weakest
Key is made the weakest
Key is made the strongest
All the three are designed for equal strength
The steel pulleys are __________ in weight than cast iron pulleys of the same capacity.
Heavier
Lighter
Moderate
None of these
According to Indian standards, total numbers of tolerance grades are
8
12
18
20
A bolt is designed on the basis of __________ with a large factor of safety.
Direct tensile stress
Direct compressive stress
Direct bending stress
Direct shear stress
The size of a cam depends upon
Base circle
Pitch circle
Prime circle
Pitch curve
I.S. specifies following total number of grades of tolerances
18
16
20
22
A type of brake commonly used in motor cars is a
Shoe brake
Band and block brake
Band brake
Internal expanding brake
In designing a connecting rod, it is considered like __________ for buckling about Y-axis.
Both ends hinged
Both ends fixed
One end fixed and the other end hinged
One end fixed and the other end free
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
In nitrated parts, the origins of the fatigue cracks will occur at
Surface
Just below the surface
Within the core
None of the above