Resilience of a material is important, when it is subjected to
Combined loading
Fatigue
Thermal stresses
Shock loading
Correct Answer :
D. Shock loading
Related Questions
Rankine's theory is used for
Brittle materials
Ductile materials
Elastic materials
Plastic materials
A crankshaft is a __________ shaft.
Transmission
Machine
Machine frame
None of these
In case of V-belt drive
The belt should touch the bottom of groove in the pulley
The belt should not touch the bottom of groove in the pulley
The belt should not touch the sides of groove in the pulley
None of the above
Two helical springs of the same material and of equal circular crosssection, length and number of turns, but having radii 80 mm and 40 mm, kept concentrically (smaller radius spring within the larger radius spring), are compressed between two parallel planes with a load W. The inner spring will carry a load equal to
W/2
2W/3
W/9
8W/9
If two springs are in parallel then their overall stiffness will be
Half
Same
Double
None of the above
The washer is generally specified by its
Outer diameter
Hole diameter
Thickness
Mean diameter
When a helical compression spring is cut into halves, the stiffness of the resulting spring will be
Same
Double
One-half
One-fourth
The valve rod in a steam engine is connected to an eccentric rod by
Cotter joint
Bolted joint
Knuckle joint
Universal coupling
A special case of ductility which permits materials to be rolled or hammered into thin sheets, is called
Plasticity
Elasticity
Ductility
Malleability
For unequal width of butt straps, the thicknesses of butt straps are
0.75 t for narrow strap on the inside and 0.625 t for wide strap on the outside
0.75 t for wide strap on the inside and 0.625 t for narrow strap on the outside
0.75 t for both the straps on the inside and outside
0.625 t for both the straps on the inside and outside
When two non-parallel or intersecting but coplanar shafts are connected by gears, the arrangement is known as,
Bevel gearing
Helical gearing
Worm gearing
None of these
The contact ratio for gears is
Zero
Less than one
Greater than one
None of these
The ball bearings are provided with a cage
To reduce friction
To facilitate slipping of balls
To prevent the lubricant from flowing out
To maintain the balls at a fixed distance apart
The permissible stress for carbon steel under static loading is generally taken as
2000-3000 kg/m²
3000-4000 kg/cm²
4000-4500 kg/cm²
7500-10,000 kg/cm²
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 statement is correct?
The cold rolled shafting is stronger than hot rolled shafting
The hot rolled shafting is stronger than cold rolled shafting
The cold rolled and hot rolled shaftings are equally strong
The shafts are not made by rolling process
In the levers of first type, the mechanical advantage is __________ one.
Less than
Equal to
More than
None of these
Screws used for power transmission should have
Very fine threads
High efficiency
Low efficiency
Strong teeth
The strength of a riveted joint is equal to
Tearing strength of plate (Pt)
Shearing strength of rivet (Ps)
Crushing strength of rivet (Pc)
Least value of Pt Ps and Pc
The included angle between the sides of V-belt is
40°
45°
38°
60°
The circumferential and longitudinal strains in a cylindrical boiler under internal steam pressure are εc and εl respectively. The change in volume of the boiler cylinder per unit volume will be
εc + 2εl
2εc + εl
εc + εl²
εc² + εl
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
A type of brake commonly used in motor cars is a
Shoe brake
Band and block brake
Band brake
Internal expanding brake
Which is correct statement?
A member made of steel will generally be more rigid than a member of equal load carrying ability made of cast iron
A member made of cast iron will generally be more rigid than a member of equal load carrying ability made of steel
Both will be equally rigid
Which one is rigid will depend on several other factors
According to Indian standard specifications, a grey cast iron designated by 'FG 200' means that the
Carbon content is 2%
Maximum compressive strength is 200 N/mm²
Minimum tensile strength is 200 N/mm²
Maximum shear strength is 200 N/mm²
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
Belt slip may occur due to
Heavy load
Loose belt
Driving pulley too small
All of the above
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 screw thread is adopted for power transmission in either direction?
Acme threads
Square threads
Buttress threads
Multiple threads
According to maximum shear stress theory, the maximum shear stress in the shaft is
(1/2) × √(σ² + 4τ²)
√(σ² + 4τ²)
(1/2) × [σ + √(σ² + 4τ²)]
σ + √(σ² + 4τ²)