Aircraft body is usually fabricated by
Welding
Pre-casting
Riveting
Casting
Correct Answer :
C. Riveting
Related Questions
Stress concentration in static loading is more serious in
Ductile materials
Brittle materials
Equally serious in both cases
Depends on other factors
Cast iron pipes are mainly used
For conveying steam
In water and sewage systems
In pressure lubrication systems on prime movers
All of the above
A hollow saddle key is
A taper key which fits half in the key way of hub and half in the key way of shaft
A taper key which fits in a key way of the hub and is flat on the shaft
A taper key which fits in a key way of the hub and the bottom of the key is shaped to fit the curved surface of the shaft
Provided in pairs at right angles and each key is to withstand torsion in one direction only
Eulers formula for a mild steel column is not valid if the slenderness ratio is
90
60
120
100
A bench vice has following type of threads
Metric
Square
Buttress
Acme
The ball bearings are, usually, made from
Low carbon steel
High carbon steel
Medium carbon steel
High speed steel
The resultant axial load on a bolt depends on
Initial tension
External load applied
Relative elastic yielding (springness) of the bolt and the connected member
All of the above
The centrifugal tension in belts
Decreases the power transmitted
Increases the power transmitted
Increase the wrap angle
Increases the belt tension without increasing power transmission
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
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 design of pin of a rocker arm of an I.C. engine is based on
Bearing failure
Shearing failure
Bending failure
All of these
Resilience of a material is important, when it is subjected to
Combined loading
Fatigue
Thermal stresses
Shock loading
For applications involving high stresses in one direction only the following type of thread would be best suited
ISO metric thread
Acme thread
Square thread
Buttress thread
The angle of twist of shaft is
Directly proportional to (shaft diameter)²
Inversely proportional to (shaft diameter)²
Directly proportional to (shaft diameter)⁴
Inversely proportional to (shaft diameter)⁴
The allowable static stress for steel gears is approximately __________ of the ultimate tensile stress.
One-fourth
One-third
One-half
Double
In a hydrodynamic lubricated bearing
There is a thick film of lubricant between the journal and the bearing
There is a thin film of lubricant between the journal and the bearing
The lubricant is forced between the journal and the bearing, by external pressure
There is no lubricant between the journal and the bearing
Residual stress in materials
Acts when external load is applied
Becomes zero when external load is removed
Is independent of external loads
Is always harmful
A steel containing upto 0.15% carbon is known as
Mild steel
Dead mild steel
Medium carbon steel
High carbon steel
When two helical springs of equal lengths are arranged to form a cluster spring, then
Shear stress in each spring will be equal
Load taken by each spring will be half the total load
Only A is correct
Both A and B is correct
When screw threads are to be used in a situation where power is being transmitted in one direction only, then the screw threads suitable for this will be
Knuckle threads
Square threads
Acme threads
Buttress threads
A localised compressive stress at the area of contact between two members is known as
Tensile stress
Bending stress
Bearing stress
Shear stress
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
Which is correct statement? Stress concentration in cyclic loading is
Very serious in brittle materials and less serious in ductile materials
Very serious in ductile materials and less serious in brittle materials
Equally serious in both types of materials
Seriousness would depend on other factors
The shock resistance of steel is increased by adding
Nickel
Chromium
Nickel and chromium
Cobalt and molybdenum
At low temperatures (say 75°C) the notched bar impact value of steel
Increases markedly
Decreases markedly
Remain same
Depends on heat treatment carried out
The effective stress in wire ropes during normal working is equal to the stress due to
Axial load plus stress due to bending
Acceleration/retardation of masses plus stress due to bending
Axial load plus stress due to acceleration/retardation
Bending plus stress due to acceleration/retardation
The ultimate strength of steel in tension in comparison to shear is in the ratio of
1 : 1
2 : 1
3 : 2
2 : 3
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
Rankine Gordon formula for buckling is valid for
Long column
Short column
Short and long column
Very long column
When a belt drive is transmitting maximum power,
Effective tension is equal to centrifugal tension
Effective tension is half of centrifugal tension
Driving tension on slack side is equal to centrifugal tension
Driving tension on tight side is twice the centrifugal tension