A column of length l is fixed at both ends. The equivalent length of the column is
l/2
l/√2
l
2 l
Correct Answer :
A. l/2
Related Questions
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 width of the pulley should be __________ width of the belt.
Equal to
Less than
Greater than
None of these
Elastic nut is a locking device in which
One small nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly in middle of nut and then slot reduced by tightening a screw
Hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is stewed 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 splitted and bent in reverse direction at other end
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
In worm gears, the angle between the tangent to the pitch helix and an element of the cylinder, is known as
Helix angle
Pressure angle
Pitch lead angle
None of these
In a belt drive, if the pulley diameter is doubled keeping the tension and belt width constant, then it will be necessary to
Increase the key length
Increase the key depth
Increase the key width
Decrease the key length
An alien bolt is
Self locking bolt
Same as stud
Provided with hexagonal depression in head
Used in high speed components
The endurance limit in shear of carbon steel can be obtained by multiplying the endurance limit in flexure by a factor of
0.45
0.55
0.65
0.75
A steel containing upto 0.15% carbon is known as
Mild steel
Dead mild steel
Medium carbon steel
High carbon steel
Which of the following is a permanent fastening?
Bolts
Keys
Cotters
Rivets
The form factor of a helical gear __________ with the increase in the helix angle.
Increases
Decreases
Remains constant
None of these
The shock resistance of steel is increased by adding
Nickel
Chromium
Nickel and chromium
Cobalt and molybdenum
In second type of levers,
Load is in between the fulcrum and effort
Effort is in between the fulcrum and load
Fulcrum is in between the load and effort
None of these
Which of the following screw thread is used for power transmission in one direction only?
Square threads
Multiple threads
Acme threads
Buttress threads
A sliding bearing which can support steady loads without any relative motion between the journal and the bearing, is called
Hydrostatic lubricated bearing
Hydrodynamic lubricated bearing
Boundary lubricated bearing
Zero film bearing
Which of the following statement is correct?
A parallel sunk key is a taperless key
A parallel sunk key may be rectangular or square in cross-section
A flat saddle key is a taper key which fits in a key way of the hub and is flat on the shaft
All of the above
The edges of a boiler plate are bevelled to an angle of
30°
45°
60°
80°
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 ratio of circumferential stress to longitudinal stress in a thin cylinder subjected to an internal pressure is
½
1
2
4
The bending moment M and a torque T is applied on a solid circular shaft. If the maximum bending stress equals to maximum shear stress developed, then M is equal to
T/2
T
2T
4T
A flange coupling is used to connect two shafts
Which are perfectly aligned
Which are not in exact alignment
Have lateral misalignment
Whose axes intersect at a small angle
In hydrostatic 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 is used for lubrication
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
In leaf springs, the longest leaf is known as
Master leaf
Lower leaf
Upper leaf
None of these
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 key way lowers
The strength of the shaft
The rigidity of the shaft
Both the strength and rigidity of the shaft
The ductility of the shaft
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 minimum number of teeth on the pinion which will mesh with any gear without interference for 20° full depth involute teeth will be
12
14
18
24
Which of the following key is preferred for the condition when a large amount of impact type torque is to be transmitted in both direction of rotation?
Woodruff key
Feather key
Gib-head key
Tangent key
Resilience of a material is important, when it is subjected to
Combined loading
Fatigue
Thermal stresses
Shock loading