Atmospheric
Slightly more than atmospheric
Slightly less than atmospheric
Pressure slightly less than atmospheric and temperature slightly more than atmospheric
D. Pressure slightly less than atmospheric and temperature slightly more than atmospheric
Carbonisation of coal
Passing steam over incandescent coke
Passing air and a large amount of steam over waste coal at about 65°C
Partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
7 : 1
15 : 1
30 : 1
50 : 1.
Compressor efficiency
Isentropic efficiency
Euler's efficiency
Pressure coefficient
Centrifugal
Reciprocating
Axial
Screw
In gas turbine plants
For operating pneumatic drills
In starting and supercharging of I.C. engines
All of the above
p₂ = (p₁ + p₃)/2
p₂ = p₁. p₃
P₂ = Pa × p₃/p₁
p₂ = Pa p₃/p₁
One adiabatic, two isobaric, and one constant volume
Two adiabatic and two isobaric
Two adiabatic, one isobaric and one constant volume
One adiabatic, one isobaric and two constant volumes
Rotor to static enthalpy rise in the stator
Stator to static enthalpy rise in the rotor
Rotor to static enthalpy rise in the stage
Stator to static enthalpy rise in the stage
Heated
Compressed air before entering the combustion chamber is heated
Bled gas from turbine is heated and readmitted for complete expansion
Exhaust gases drive the compressor
Same as isothermal
Same as adiabatic
Better than isothermal and adiabatic
In between isothermal and adiabatic
In one cylinder
In two cylinders
In a single cylinder on both sides of the piston
In two cylinders on both sides of the piston
Multistage compression
Cold water spray
Both (A) and (B) above
Fully insulating the cylinder
Equal to
Less than
More than
None of these
1
1.2
1.3
1.4
Inlet losses
Impeller channel losses
Diffuser losses
All of the above
34 %
50 %
60 %
72 %
Parallel
Perpendicular
Inclined
None of these
Decreasing the compression work
Increasing the compression work
Increasing the turbine work
Both (A) and (C) above
Remove impurities from air
Reduce volume of air
Cause moisture and oil vapour to drop out
Cool the air
Rise gradually towards the point of use
Drop gradually towards the point of use
Be laid vertically
Be laid exactly horizontally
Increases thermal efficiency
Allows high compression ratio
Decreases heat loss is exhaust
Allows operation at very high altitudes
A.C. electric motor
Compressed air
Petrol engine
Diesel engine
One stroke
Two strokes
Three strokes
Four strokes
In a two stage reciprocating air compressor with complete intercooling, maximum work is saved.
The minimum work required for a two stage reciprocating air compressor is double the work required for each stage.
The ratio of the volume of free air delivery per stroke to the swept volume of the piston is called volumetric efficiency.
None of the above
Ratio of shaft output of the air motor to the shaft input to the compressor
Ratio of shaft input to the compressor to the shaft output of air motor
Product of shaft output of air motor and shaft input to the compressor
None of the above
Stainless steel
High alloy steel
Duralumin
Timken, Haste alloys
Adding heat exchanger
Injecting water in/around combustion chamber
Reheating the air after partial expansion in the turbine
All of the above
Vacuum
Atmospheric air
Compressed air
Oxygen alone
The reciprocating compressors are best suited for high pressure and low volume capacity
The effect of clearance volume on power consumption is negligible for the same volume of discharge
Both (A) and (B)
None of these
The propulsive matter is ejected from within the propelled body
The propulsive matter is caused to flow around the propelled body
Its functioning does not depend upon presence of air
None of the above