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
Correct Answer :
A. Net work output and work done by turbine
Related Questions
Gas turbine as compared to internal combustion engine
Can be driven at a very high speed
Produces uniform torque
Has more efficiency
All of these
A closed cycle gas turbine works on
Carnot cycle
Rankine cycle
Ericsson cycle
Joule cycle
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
If the clearance ratio for a reciprocating air compressor is 'K', then its volumetric efficiency is given by
1 - k + k (p₁/p₂)1/n
1 + k - k (p₂/p₁)1/n
1 - k + k (p₁/p₂) n- 1/n
1 + k - k (p₂/p₁) n-1/n
Axial flow compressor resembles
Centrifugal pump
Reciprocating pump
Turbine
Sliding vane compressor
The working fluid in a turbine is
In two phases
In three phases
In a single phase
In the form of air and water mixture
In gas turbines, high thermal efficiency is obtained in
Closed cycle
Open cycle
Both of the above
Closed/open depending on other considerations
The pressure ratio for an open cycle gas turbine compared to closed cycle gas turbine of same h.p. is
Low
High
Same
Low/high depending on make and type
The ratio of the increase in pressure in rotor blades to total increase in pressure in the stage is called
Pressure ratio
Pressure coefficient
Degree of reaction
Slip factor
The volume of air delivered by the compressor is called
Free air delivery
Compressor capacity
Swept volume
None of these
Ram compression in turbojet involves
Reduction of speed of incoming air and conversion of part of it into pressure energy
Compression of inlet air
Increasing speed of incoming air
Lost work
If V, U and Vr represent the absolute velocity of fluid, velocity of blade, and relative velocity of fluid, and suffix I and o stand for entry and exit conditions, then in a rotary machine whose degree of reaction is unity
Vi = Vo
Vt > Vo
U < Vo
V = Uo
The compression ratio in a gas turbine is of the order of
3.5 : 1
5 : 1
8 : 1
12 : 1
Which is false statement about air receivers?
These are used to dampen pulsations
These act as reservoir to take care of sudden demands
These increase compressor efficiency
These knock out some oil and moisture
For a two stage compressor, if index of compression for higher stage is greater than index of compression for lower stage, then the optimum pressure as compared to ideal case will
Increase
Decrease
Remain unaffected
Other factors control it
Reheating in multistage expansion gas turbine results in
High thermal efficiency
Reduction in compressor work
Decrease of heat loss in exhaust
Maximum work output
In a compressor, free air delivered is the actual volume delivered at the stated pressure reduced to
N.T.P. conditions
Intake temperature and pressure conditions
0°C and 1 kg/cm²
20°C and 1 kg/cm²
A closed gas turbine in which fuel is burnt directly in the air is not possible because of
Paucity of O2
Increasing gas temperature
High specific volume
High friction losses
In which case the air-fuel ratio is likely to be maximum?
Gas turbine
4-stroke petrol engine
4-stroke diesel engine
Multi cylinder engine
Standard air is the air at
Atmospheric conditions at any specific location
20°C and 1 kg/cm² and relative humidity 36%
0°C and standard atmospheric conditions
15°C and 1 kg/cm²
Euler's equation is applicable for
Centrifugal compressor
Axial compressor
Pumps
All of the above
Free air is the air at
Atmospheric conditions at any specific location
20°C and 1 kg/cm² and relative humidity of 36%
0°C and standard atmospheric conditions
15°C and 1 kg/cm²
In multistage compressor, the isothermal compression is achieved by
Employing intercooler
By constantly cooling the cylinder
By running compressor at very slow speed
By insulating the cylinder
The process, which causes the air to enter the impeller blades of a centrifugal compressor at ________ velocity (without effecting the mass of air to flow and velocity of flow) is known as prewhirl.
Reduced
Increased
Zero
None of these
Reheating in a multistage expansion gas turbine __________ compressor work.
Has no effect on
Decreases
Increases
None of these
The inlet pressure is always ________ the discharge pressure.
Equal to
Less than
More than
None of these
Mining industry usually employs following motive power
A.C. electric motor
Compressed air
Petrol engine
Diesel engine
A simple turbojet engine is basically
A propeller system
Gas turbine engine equipped with a propulsive nozzle and diffuse
Chemical rocket engine
Ramjet engine
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
Only rocket engines can be propelled to space because
They can generate very high thrust
They have high propulsion efficiency
These engines can work on several fuels
They are not air breathing engines