In case of compression of one kg of air, the work done will be the least, when the value of polytropic index 'n' is
1
1.4
1.5
Y = Cp/Cv
Correct Answer :
A. 1
Related Questions
Catalyst used in the catalytic converter employed in automobiles to convert CO into CO2 and for complete oxidation of un-burnt hydrocarbons is
Nickel
Cobalt
Vanadium
Platinum
Use of economiser in a boiler plant reduces the fuel consumption for steam generation by about __________ percent.
1
10
30
50
The specific gravity of coal depends mainly on its __________ content.
Carbon
Volatile matter
Ash
Moisture
For dynamic strain measurement, the Wheatstone bridge used is of __________ type.
Voltage sensitive null
Voltage sensitive deflected
Current sensitive deflected
None of these
Drills are usually made of
Cermets
High speed steel
Alloy steel
Tungsten carbide
The ratio of the shear stress to the principal stress on a principal plane is
0
1
1/2
1/3
Speisses is a mixture of the following:
Arsenides of heavy metals
Antimonides of heavy metals
Arsenides & antimonides of heavy metals
Iron, cobalt and nickel
Ammonia leakage in the refrigeration system is detected by
Sulphur stick, which on detection gives white smoke
Using chemical reagents
Its smell
Soap solution
The most suitable material of construction for a sewer to carry sewage under high pressure is
Asbestos cement
Steel
Cement concrete
Stoneware
Hydrogen in liquid steels is dissolved
As tiny gas bubbles
In the atomic form
In the ionic form
In the molecular form
Which of the following is an example of stress corrosion?
Season cracking of brass
Caustic embrittlement of steel
Both (A) & (B)
Neither (A) nor (B)
Propulsion of rocket follows from the
Newton's second law of motion
Newton's third law of motion
Law of projectiles
Archimedes principle
Case hardening is not done by
Nitriding
Hot dipping
Electroplating
Both b & c
Quartz is a __________ material.
Diamagnetic
Ferromagnetic
Ferroelectric
Piezoelectric
Which of the following is resistant to the action of both heat & chemicals?
Borosilicate glass
Silica glass
Soda lime glass
None of these
A psychrometer does not measure the __________ temperature of moist air.
Dew point
Dry bulb
Wet bulb
None of these
The life of a ball bearing is inversely proportional to
(Load)1
(Load)2
(Load)3
(Load)0.33
Temper brittleness of a material can be fairly detected by the __________ test.
Fatigue
Notched bar impact
Tensile
Hardness
A common disinfectant used in village wells for disinfection of water is
Free chlorine
Bromine
Iodine
Potassium permanganate
A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will
Increase
Decrease
Remain unaffected
May increase or decrease; depends on the thickness of each layer
If Reynolds number is greater than 1, then the
Viscous force is larger than the inertia force
Inertia force is larger than the viscous force
Inertia force is larger than the surface tension force
Inertia force is larger than the gravitational force
A semi-conductor is damaged & behaves like a conductor, on passing a strong electric current through it, because it heats up the crystals & breaks the covalent bonds resulting in __________ electrons.
Lack of free
Excess of
Decrease in
None of these
Hollow shafts can be made as strong as solid shafts by making the twisting moments of both the shafts same. Shafts made by __________ have residual stresses.
Forging
Cold rolling
Hot rolling
Casting
More than 95% of __________ is present in corundum.
SiO2
Al2O3
CaSiO2
MgO
Age hardening is connected with
Babbitt metal
Gun metal
Stainless steel
Duralumin
In a good rimming steel
Carbon and silicon should be low
Silicon should be low but carbon should be high
Both silicon & carbon should be high
Silicon should be high but carbon should be low
Which of the following materials has the maximum shrinkage allowance?
Brass
Cast iron
Lead
Aluminium alloy
Cascade control is
The continuous adjustment of the set point index of an automatic control loop by a primary (master) controller
Used when changes in process conditions cause serious upsets in the controlled variable
Useful to control flow from temperature
All 'a', 'b' & 'c'
The activity co-efficient of the solute in a dilute solution
Decreases with the increase of concentration of the solute
Increases with the increase of concentration of the solute
Remains constant
Is unity at infinite dilution
Though tin occurs lower than iron in the electrochemical series, yet it is coated on steel for corrosion protection, because of its
Lower cost
Abundant availability
Resistance to vegetable acids as the tin plate are commercially used in 'canning' industry
None of these