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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.A closed cycle gas turbine consists of a
- ACompressor
- BHeating chamber
- CCooling chamber
- DAll of these
2.The thermal efficiency of a simple gas turbine for a given turbine inlet temperature with increase in pressure ratio
- AIncreases
- BDecreases
- CFirst increases and then decreases
- DFirst decreases and then increases
3.The pressure ratio of an ideal vaned compressor with increase in mass flow rate
- AIncreases
- BDecreases
- CRemain constant
- DFirst decreases and then increases
4.With the decrease in compression ratio, the volumetric efficiency
- ADoes not change
- BIncreases
- CDecreases
- DFirst decrease and then increase
5.In which case the air-fuel ratio is likely to be maximum?
- AGas turbine
- B4-stroke petrol engine
- C4-stroke diesel engine
- DMulti cylinder engine
6.A compressor at high altitude will draw
- AMore power
- BLess power
- CSame power
- DMore/less power depending on other factors
7.An ideal air compressor cycle with clearance on P-V diagram can be represented by following processes
- AOne adiabatic, two isobaric, and one constant volume
- BTwo adiabatic and two isobaric
- CTwo adiabatic, one isobaric and one constant volume
- DOne adiabatic, one isobaric and two constant volumes
8.An ideal air compressor cycle without clearance on P-V diagram can be represented by following processes
- AOne adiabatic, two isobaric, and one constant volume
- BTwo adiabatic and two isobaric
- CTwo adiabatic, one isobaric and one constant volume
- DOne adiabatic, one isobaric and two constant volumes
9.Gas turbines use following type of air compressor
- ACentrifugal type
- BReciprocating type
- CLobe type
- DAxial flow type
10.The power available for takeoff and climb in case of turbojet engine as compared to reciprocating engine is
- ALess
- BMore
- CSame
- DMay be less or more depending on ambient conditions
11.In the axial flow gas turbine, the work ratio is the ratio of
- ACompressor work and turbine work
- BOutput and input
- CActual total head temperature drop to the isentropic total head drop from total head inlet to static head outlet
- DActual compressor work and theoretical compressor work
12.High air-fuel ratio in gas turbines
- AIncreases power output
- BImproves thermal efficiency
- CReduces exhaust temperature
- DDo not damage turbine blades
13.Euler's equation can be used for
- ARadial flow compressors
- BAxial flow compressors
- CPumps
- DAll of these
14.The thrust of a jet propulsion power unit can be increased by
- AInjecting water into the compressor
- BBurning fuel after gas turbine
- CInjecting ammonia into the combustion chamber
- DAll of the above
15.The efficiency and work ratio of a gas turbine plant can be increased by
- AAdding heat exchanger
- BInjecting water in/around combustion chamber
- CReheating the air after partial expansion in the turbine
- DAll of the above
16.Inter-cooling in multistage compressors is done
- ATo cool the air during compression
- BTo cool the air at delivery
- CTo enable compression in two stages
- DTo minimize the work of compression
17.For maximum work, the reheating should be done to an intermediate pressure of (Where p₁ = Maximum pressure, and p₂ = Minimum pressure)
- A(p₁ - p₂)/2
- B(p₁ + p₂)/2
- Cp₁/p₂
- Dp₁ p₂
18.Volumetric efficiency of a compressor decreases with ________ in compression ratio.
- ADecrease
- BIncrease
- CRemain same
- DDoes not change
19.If p₁ is the pressure of air entering the L.P, cylinder and p₃ is the pressure of air leaving the H.P. cylinder, then the ratio of cylinder diameters for a single acting, two stage reciprocating compressor with complete intercooling is given by
- AD₁/D₂ = (p₁ p₃)1/2
- BD₁/D₂ = (p₁/p₃)1/4
- CD₁/D₂ = (p₁ p₃)1/4
- DD₁/D₂ = (p₃/p₁)1/4
20.In n₁ and n₂ are the indices of compression for the first and second stage of compression, then the ratio of work-done on the first and second stages (W₁/W₂) with perfect intercooling is given by
- AW₁/W₂ = n₂(n₁ - 1)/n₁(n₂ - 1)
- BW₁/W₂ = n₁(n₂ - 1)/n₂(n₁ - 1)
- CW₁/W₂ = n₁/n₂
- DW₁/W₂ = n₂/n₁