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Compressors, Gas Turbines And Jet Engines MCQ
300 Important Compressors, Gas Turbines And Jet Engines MCQ Question and Answer | PDF Free Download
1.The degree of reaction in an axial flow compressor is defined as the ratio of static enthalpy rise in the
- ARotor to static enthalpy rise in the stator
- BStator to static enthalpy rise in the rotor
- CRotor to static enthalpy rise in the stage
- DStator to static enthalpy rise in the stage
2.The efficiency of a jet engine is higher at
- ALow speeds
- BLow altitudes
- CHigh altitudes
- DHigh speeds
3.A simple turbojet engine is basically
- AA propeller system
- BGas turbine engine equipped with a propulsive nozzle and diffuse
- CChemical rocket engine
- DRamjet engine
4.The most efficient method of compressing air is to compress it
- AIsothermally
- BAdiabatically
- CIsentropically
- DIsochronically
5.In a centrifugal compressor, the flow of air is ________ to the axis of compressor.
- AParallel
- BPerpendicular
- CInclined
- DNone of these
6.In a single stage, single acting reciprocating air compressor, without clearance volume, the work-done is minimum during
- AIsothermal compression
- BIsentropic compression
- CPolytropic compression
- DNone of these
7.In a single stage, single acting reciprocating air compressor without clearance volume, the work-done is maximum during
- AIsothermal compression
- BIsentropic compression
- CPolytropic compression
- DNone of these
8.The compressor capacity is defined as the
- AActual volume of the air delivered by the compressor when reduced to normal temperature and pressure conditions
- BVolume of air delivered by the compressor
- CVolume of air sucked by the compressor during its suction stroke
- DNone of the above
9.Axial flow compressor has the following advantage over centrifugal compressor
- ALarger air handling ability per unit frontal area
- BHigher pressure ratio per stage
- CAerofoil blades are used
- DHigher average velocities
10.If the clearance ratio for a reciprocating air compressor is 'K', then its volumetric efficiency is given by
- A1 - k + k (p₁/p₂)1/n
- B1 + k - k (p₂/p₁)1/n
- C1 - k + k (p₁/p₂) n- 1/n
- D1 + k - k (p₂/p₁) n-1/n
11.In a centrifugal compressor, the highest Mach number leading to shock wave in the fluid flow occurs at
- ADiffuser inlet radius
- BDiffuser outlet radius
- CImpeller inlet radius
- DImpeller outlet radius
12.The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is
- ALess
- BMore
- CSame
- DMore/less depending on compressor capacity
13.The volumetric efficiency of a compressor falls roughly as follows for every 5°C increase in atmospheric temperature
- A0.1%
- B0.5%
- C1%
- D5%
14.In a centrifugal compressor, the ratio of the ________ to the blade velocity is called slip factor.
- AInlet whirl velocity
- BOutlet whirl velocity
- CInlet velocity of flow
- DOutlet velocity of flow
15.For slow speed large capacity compressor, following type of valve will be best suited
- APoppet valve
- BMechanical valve of the Corliss, sleeve, rotary or semi rotary type
- CDisc or feather type
- DAny of the above
16.It is not possible to use closed gas turbine cycle in aeronautical engines because
- AIt is inefficient
- BIt is bulky
- CIt requires cooling water for its operation
- DNone of the above
17.The capacity of compressor will be highest when its intake temperature is
- ALowest
- BHighest
- CAnything
- DAtmospheric
18.In a high pressure compressor, the delivery pressure is
- A1 to 5 bar
- B5 to 8 bar
- C8 to 10 bar
- D10 to 15 bar
19.The effective power of gas turbines is increased by adding the following in compressor
- AAmmonia and water vapour
- BCarbon dioxide
- CNitrogen
- DHydrogen
20.During base load operation, the best method of controlling compressor is
- AStart-stop motor
- BConstant speed unloader
- CRelief valve
- DVariable speed