The maximum combustion pressure in gas turbine as compared to I.C. engine is
More
Less
Same
Depends on other factors
Correct Answer :
B. Less
Related Questions
A closed cycle gas turbine consists of a
Compressor
Heating chamber
Cooling chamber
All of these
In gas turbines, high thermal efficiency is obtained in
Closed cycle
Open cycle
Both of the above
Closed/open depending on other considerations
Mechanical efficiency of gas turbines as compared to I.C engines is
Higher
Lower
Same
None of the above
If the flow of air through the compressor is perpendicular to its axis, then it is a
Reciprocating compressor
Centrifugal compressor
Axial flow compressor
Turbo compressor
Choose the correct statement
Gas turbine requires lot of cooling water
Gas turbine is capable of rapid start up and loading
Gas turbines has flat efficiency at part loads
Gas turbines have high standby losses and require lot of maintenance
Work ratio of a gas turbine plant is ratio of
Net work output and work done by turbine
Net work output and heat supplied
Work done by turbine and heat supplied
Work done by turbine and net work output
The inlet pressure is always ________ the discharge pressure.
Equal to
Less than
More than
None of these
An ideal air compressor cycle without clearance on PV diagram can be represented by following processes
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
Surging is the phenomenon of
Air stream blocking the passage
Motion of air at sonic velocity
Unsteady, periodic and reversed flow
Air stream not able to follow the blade contour
A machine used to raise the pressure of air is called
Gas turbine
I.C engine
Compressor
Air motor
The ratio of the volume of free air delivery per stroke to the swept volume of the piston, is known as
Compressor efficiency
Volumetric efficiency
Isothermal efficiency
Mechanical efficiency
A rocket engine for the combustion of its fuel
Carries its own oxygen
Uses surrounding air
Uses compressed atmospheric air
Does not require oxygen
The ratio of work done per cycle to the swept volume in case of compressor is called
Compression index
Compression ratio
Compressor efficiency
Mean effective pressure
The pressure ratio in gas turbines is of the order of
2 : 1
4 :1
61 : 1
9 : 1
The pressure and temperature conditions of air at the suction of compressor are
Atmospheric
Slightly more than atmospheric
Slightly less than atmospheric
Pressure slightly less than atmospheric and temperature slightly more than atmospheric
Maximum delivery pressure is a rotary air compressor is of the order of
6 kg/cm²
10 kg/cm²
16 kg/cm²
25 kg/cm²
Pick up the correct statement
Closed cycle gas turbine is an I.C engine
Gas turbine uses same working fluid over and over again
Ideal efficiency of closed cycle gas turbine plant is more than Carnot cycle efficiency
Thrust in turbojet is produced by nozzle exit gases.
Ramjet engine
Is self operating at zero flight speed
Is not self operating at zero flight speed
Requires no air for its operation
Produces a jet consisting of plasma
The air power of the compressor is also known as
Indicated power
Brake power
Frictional power
None of these
Separators in compressor installations are located
Before intercooler
After intercooler
After receiver
Between after-cooler and air receiver
A 3 m³/min compressor means that it
Compresses 3 m³/min of standard air
Compresses 3 m³/ min of free air
Delivers 3 m³/ min of compressed air
Delivers 3 m³/ min of compressed air at delivery pressure
Rotary compressors are suitable for
Large discharge at high pressure
Low discharge at high pressure
Large discharge at low pressure
Low discharge at low pressure
Cylinder clearance in a compressor should be
As large as possible
As small as possible
About 50% of swept volume
About 100% of swept volume
In a jet propulsion
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
Which of the following statement is correct relating to rocket engines?
The combustion chamber in a rocket engine is directly analogous to the reservoir of a supersonic wind tunnel
The stagnation conditions exist at the combustion chamber
The exit velocities of exhaust gases are much higher than those in jet engine
All of the above
For supplying intermittent small quantity of air at high pressure, following compressor is best suited
Centrifugal
Reciprocating
Axial
Screw
A centrifugal compressor works on the principle of
Conversion of pressure energy into kinetic energy
Conversion of kinetic energy into pressure energy
Centripetal action
Generating pressure directly
The efficiency of the vane blower is (where W₁ = Workdone due to compression, and W₂ = Workdone due to back flow)
W₁/(W₁ + W₂)
W₂/(W₁ + W₂)
(W₁ + W₂)/W₁
(W₁ + W₂)/W₂
A compressor mostly used for supercharging of I.C. engines is
Radial flow compressor
Axial flow compressor
Roots blower
Reciprocating compressor
Isothermal compression though most efficient, but is not practicable because
It requires very big cylinder
It does not increase pressure much
It is impossible in practice
Compressor has to run at very slow speed to achieve it