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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 pressure ratio for an open cycle gas turbine compared to closed cycle gas turbine of same h.p. is
- ALow
- BHigh
- CHigh
- DLow/high depending on make and type
2.Efficiency of gas turbine is increased by
- AReheating
- BInter cooling
- CAdding a regenerator
- DAll of the above
3.The closed cycle in gas turbines
- AProvides greater flexibility
- BProvides lesser flexibility
- CIn never used
- DIs used when gas is to be burnt
4.The specific output per kg mass flow rate of a gas turbine (having fixed efficiencies of compressor and turbine and fixed higher and lower temperature) with increase in pressure ratio will
- AIncrease first at fast rate and then slow
- BIncrease first at slow rate and then fast
- CDecrease continuously
- DFirst increase, reach maximum and then decrease
5.The stagnation pressure rise in a centrifugal compressor takes place
- AIn the diffuser only
- BIn the impeller only
- CIn the diffuser and impeller
- DIn the inlet guide vanes only
6.The ratio of work-done per cycle to the stroke volume of the compressor is known as
- ACompressor capacity
- BCompression ratio
- CCompressor efficiency
- DMean effective pressure
7.The thermodynamic efficiency of rotary compressor is based on
- AIsothermal compression
- BAdiabatic compression
- CIsentropic compression
- DPolytropic compression
8.The volumetric efficiency of compressor with increase in compression ratio will
- AIncrease
- BDecrease
- CRemain same
- DMay increase or decrease depending on clearance volume
9.The volumetric efficiency of a compressor falls roughly as follows for every 100 m increase in elevation
- A0.1%
- B0.5%
- C1.0%
- D5%
10.The ratio of the increase in pressure in rotor blades to total increase in pressure in the stage is called
- APressure ratio
- BPressure coefficient
- CDegree of reaction
- DSlip factor
11.A compressor mostly used for supercharging of I.C. engines is
- ARadial flow compressor
- BAxial flow compressor
- CRoots blower
- DReciprocating compressor
12.A jet engine works on the principle of conservation of
- AMass
- BEnergy
- CFlow
- DLinear momentum
13.The mass of gas turbine per kW developed is about ________ as that of an I.C. engine.
- ASame
- BOne-half
- COne fourth
- DOne sixth
14.When the temperature of air leaving the inter-cooler, in a two stage compression with inter-cooler, is ________ the original atmospheric air temperature, then the intercooling is known as perfect or complete intercooling.
- AEqual to
- BLess than
- CMore than
- DNone of these
15.The following property is most important for material used for gas turbine blade
- AToughness
- BFatigue
- CCreep
- DCorrosion resistance
16.The main purpose of reheating in gas turbine is to
- AIncrease temperature
- BReduce turbine size
- CIncrease power output
- DIncrease speed
17.In the cross compounding of the gas turbine plant
- AH.P. compressor is connected to H.P. turbine and L.P. compressor to L.P. turbine
- BH.P. compressor is connected to L.P. turbine and L.P. compressor is connected to H.P. turbine
- CBoth the arrangements can be employed
- DAll are connected in series
18.The advantage of multistage compression over single stage compression is
- ALower power consumption per unit of air delivered
- BHigher volumetric efficiency
- CDecreased discharge temperature
- DAll of the above
19.1 m of air at atmospheric condition weighs approximately
- A0.5 kg
- B1.0 kg
- C1.3 kg
- D2.2 kg
20.In air compressors, free air delivery means 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