Latest Competitive Mechanical Engineering MCQs – Compressors, Gas Turbines and Jet Engines MCQs

Latest Competitive Mechanical Engineering MCQs – Compressors, Gas Turbines and Jet Engines MCQs

This post is comprising of latest ” Compressors, Gas Turbines and Jet Engines MCQs Latest – Competitive Mechanical Engineering MCQs “. Here you’ll get latest mechanical engineering mcqs for written test, interview with answers. If you want to improve your knowledge regarding mechanical engineering then read these mcqs of Design of Steel Structures.

Latest Mechanical Engineering MCQs

By practicing these MCQs of Mechanical Engineering MCQs – Compressors, Gas Turbines and Jet Engines Mcqs, an individual for exams performs better than before. This post comprising of mechanical engineering objective questions and answers related to Compressors, Gas Turbines and Jet Engines“. As wise people believe “Perfect Practice make a Man Perfect”. It is therefore practice these mcqs of mechanical engineering to approach the success. Tab this page to check “Latest Compressors, Gas Turbines and Jet Engines Mcqs” for the preparation of competitive mcqs, FPSC mcqs, PPSC mcqs, SPSC mcqs, KPPSC mcqs, AJKPSC mcqs, BPSC mcqs, NTS mcqs, PTS mcqs, OTS mcqs, Atomic Energy mcqs, Pak Army mcqs, Pak Navy mcqs, CTS mcqs, ETEA mcqs and others.

Latest Compressors, Gas Turbines and Jet Engines Mcqs

The most occurred mcqs of Compressors, Gas Turbines and Jet Engines in past papers. Past papers of Compressors, Gas Turbines and Jet Engines Mcqs. Past papers of Compressors, Gas Turbines and Jet Engines Mcqs . Mcqs are the necessary part of any competitive / job related exams. The Mcqs having specific numbers in any written test. It is therefore everyone have to learn / remember the related Compressors, Gas Turbines and Jet Engines Mcqs. The Important series of Compressors, Gas Turbines and Jet Engines Mcqs are given below:

Gas turbine works on_______________?

A. Brayton or Atkinson cycle
B. Rankine cycle
C. Carnot cycle
D. Erricsson cycle
E. Joule cycle

Gas turbine works on______________?

A. Brayton or Atkinson cycle
B. Rankine cycle
C. Carnot cycle
D. Erricsson cycle
E. Joule cycle

Rotary compressors are suitable for ____________________?

A. low discharge at high pressure
B. large discharge at high pressure
C. large discharge at low pressure
D. low discharge at low pressure
E. there is no such limitation

The work ratio of a gas turbine plant is defined as the ratio of__________________?

A. actual heat drop and isentropic heat drop
C. net work output and heat supplied (6) net work output and work done by tur¬bine
D. net work output and isentropic heat drop
E. isentropic increase/drop in tempera¬ture and actual increase/ drop in temperature

The pressure ratio for an open cycle gas turbine compared to closed cycle gas turbine of same h.p. is_______________?

A. low
B. same
C. high
D. low/high depending on make and type
E. unpredictable

The fuel consumption in gas turbines is accounted for by___________________?

A. low.er heating value
B. heating value
C. higher heating value
D. higher calorific value
E. highest calorific value

Mechanical efficiency of gas turbines as compared to I.C engines is____________________?

A. higher
B. same
C. lower
D. depends on on odier considerations
E. unpredictable

The air-fuel ratio in gas turbines is of the order of ______________________?

A. 15 : 1
B. 7 : 1
C. 30 : 1
D. 40 : 1
E. 50: 1

Gas turbine blades are given a rake___________________?

A. depending on the velocity
B. in the direction of motion of blades
C. opposite to the direction of motion of blades
D. equal to zero
E. none of the above

The thermal efficiency of a gas turbine as compared to a diesel plant is__________________?

A. more
B. same
C. less
D. depends on other factors
E. unpredictably

The ratio of specific weighf/h.p. of gas turbine and I.C engines may be typically of the order of_______________________?

A. 2 : 1
B. 1 : 1
C. 4 : 1
D. 1:2
E. 1 : 6

The pressure ratio in gas turbines is of the order of__________________?

A. 4:1
b. 2:l
C. 61: 1
D. 9 : 1
E. 12:1.

Temperature of gases at end of compression as compared to exhaust gases in a gas turbine is_________________?

A. equal
B. lower
C. higher
D. can’t be compared
E. unpredictable

The hottest point in a gas turbine is______________________?

A. at the tip
B. at the base
C. in the center
D. between ~ to i of the blade height
E. uniformly heated

Efficiency of gas turbine is increased by________________ ?

A. inter cooling
B. reheating
C. adding a regenerator
D. all of the above
E. none of the above

The following is true for an open cycle gas turbine having exhaust heat exchanger. Atmospheric air before entering the compressor is____________________?

A. exhaust gases drive the compressor
B. compressed air before entering the combustion chamber is heated
C. bled gas from turbine is heated and readmitted for complete expansion
D. heated
E. part of exhaust gases are heated and mixed up with atmospheric air to utilise exhaust heat

The thermal efficiency of a simple gas turbine for a given turbine inlet temperature with increase in pressure ratio_____________________?

A. increases
B. first increases and then decreases
C. decreases
D. first decreases and then increases
E. remains same

Water gas is produced by ___________________ ?

A. same way as the natural gas
B. passing steam over incandescent coke
C. passing air and a large amount of steam over waste coal at about 65°C
D. partial combustion of caol, eke, anthractie coal or charcoal in a mixed air steam blast
E. carbonisation of coal

The combustion efficiency of a gas turbine using perfect combustion chamber is of the order of________________?

A. 75%
B. 50%
C. 85%
D. 90%
E. 99%

There is a certain pressure ratio (optimum) for a gas turbine at which its thermal efficiency is maximum. With increase in turbine temperature, the value of pressure ratio for the peak efficiency would__________________?

A. decrease
B. remain same
C. increase
D. unpredictable
E. none of the above

The ideal efficiency of simple gas turbine cycle depends on________________?

A. pressure ratio
B. minimum cycle temperature
C. maximum cycle temperature
D. all of the above
E. none of the above

The material commonly used for air craft gas turbine is__________________?

A. high alloy’ steel
B. stainless steel
C. duralumin
D. Timken, Haste and Inconel allpys
E. titanium

The jnaximum combustion pressure in gas turbine as compared to I.C. engine is_________________?

A. same
B. less
C. more
D. depends on other factors
E. unpredictable

As the turbine inlet temperature increases, the thermal efficiency of gas turbine for the optimum pressure ratio_____________________?

A. increases
B. remains same
C. decreases
D. first increases and then decreases
E. first decreases and then increases

It is not possible to use closed gas turbine cycle in aeronautical engines because_________________ ?

A. it is bulky
B. it is inefficient
C. it requires cooling water for its operation
D. non of theses

For an irreversible gas turbine cycle, the efficiency and work ratio both depend on___________________?

A. maximum cycle temperature alone
B. pressure ratio alone
C. minimum cycle temperature alone
D. both pressure ratio and maximum cycle temperature
E. none of the above

Producer gas is produced by_____________________?

A. passing steam over incandescent coke
B. carbonisation of coal
C. passing air and a large amount of steam over waste coal at about 65°C
D. partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
E. same way as the natural gas

Fluid Mechanics Mcqs

A gas turbine used in air craft should have______________________?

A. high speed and high h.p.
B. low weight and small frontal area
C. small frontal area and high h.p.
D. high h.p. and low weight
E. all of the above

The degree of reaction of an axial flow turbine is the ratio of isentropic temperature drop in a blade row to the_____________________?

A. adiabatic temperature drop in the stage
B. total adiabaitc temperature drop
C. total temperature drop in the stage
D. total temperature drop
E. difference of maximum and minimum temperature in the cycle

The closed cycle in gas turbines_________________?

A. provides greater flexibility
B. in never used
C. provides lesser flexibility
D. is used when gas is to be burnt
E. none of the above

Water is injected in gas turbine cycle to___________________?

A. control fire hazards
B. control output of turbine
C. control temperature
D. increase efficiency
E. it is never done

In the axial flow gas turbine, the work ratio is the ratio of____________________?

A. output and input
B. compressor work and turbine work
C. actual total head tempeature drop to the isentrpic total head drop from total head inlet to static head outlet
D. actual compressor work and theoretical comprssor work
E. none of the above

A closed gas turbine in which fuel is burnt directly in the air is not possible because of__________________?

A. high specific volume
B. increasing gas temperature
C. high pressure ratio
D. high friction losses
E. paucity of 02

In gas turbines^ high thermal efficiency is obtained in_________________?

A. closed cycle
B. both of the above
C. open cycle
D. closed/open depending on other con-siderations
E. unpredictable

In jet engines, for the efficient production of large power, fuel is burnt in an atmosphere of__________________?

A. atmospheric air
B. vacuum
C. compressed air
D. oxygen alone
E. liquid hydrogen

Turbo propeller has the following additional feature over the turbojet __________________?

A. peopeller
B. intercooler
C. diffuser
D. turbine and combustion chamber
E. starting engine

In jet engines, paraffin is usually used as the fuel because of its _________________?

A. low freezing point
B. ease of atomisation
C. high calorific value
D. A. and C. above
E. none of the above

If infinite number of heaters be used in a gas turbine, then expansion process in turbine approaches _________________?

A. isothermal
B. adiabatic
C. isentropic
D. isochoric
E. isobaric

Intercooling in gas turbine results in ____________________ ?

A. increase in net output but decrease in thermal efficiency
B. increase in both thermal efficiency and net output
C. increase in thermal efficiency but decrease in net output
D. decrease in both thermal efficiency and net output
E. none of the above

The power available for take off and climb in case of turbojet engine as compared to reciprocating engine is ___________________?

A. less
B. same
C. more
D. may be less or more depending on ambient conditons
E. unpredictable

Ram compression in turbojet involves____________________?

A. reduction of speed of incoming air and conversion of part of it into pressure energy
B. lost work
C. increasing speed of incoming air
D. compression of inlet air
E. leakage losses

A jet engine works on the principle of conservation of____________________?

A. energy
B. mass
C. flow
D. linear momentum
E. angular momentum

Which of the following fuels can be used in turbojet engines _____________________?

A. high speed diesel oil
B. liquid hydrogne
C. kerosene
D. demethylated spirit
E. methyl alcohol

A rocket engine for the combustion of its fuel_____________________?

A. carries its own oxygen
B. uses compressed atmospheric air
C. uses surrounding air
D. does not require oxygen
E. depends on electrical energy supplied by solar cells

Propulsive efficiency is defined as ratio of___________________?

A. engine output and propulsive power
B. thrust power and fuel energy
C. propulsive power and fuel input
D. thrust power and propulsive power
E. none of the above

In the cross compounding of the gas turbine plant__________________?

A. both the arrangements can be employed
B. h.p. compressor is connected to l.p. turbine and l.p. compressor is con-nected to h.p. turbine
C. h.p. compressor L connected to h.p. turbine and l.p. compressor ot l.p. tur-bine
D. all are connected in series
E. none of the above

A rocket works with maximum overall efficiency when air craft velocity is equal to the_________________?

A. twice the jet velocity
B. jet velocity
C. half the jet velocity
D. average of the jet velocity
E. no such co-relationship with jet velocity exists

The maximum propulsion efficiency of a turbojet is attained at around following speed __________________?

A. 1050km/hr
B. 550 km/hr
C. 1700 km/hr
D. 2400km /hr
E. 4000 km/hr

Propulsion efficiency of the following order-is obtained in practice _______________?

A. 50%
B. 34%
C. 60%
D. 72%
E. 85%.

The air entry velocity m a rocket as compared to aircraft is_________________?

A. more
B. same
C. less
D. zero
E. dependent on power and speed

In jet propulsion power unit, the inlet duct of diverging shape is used in order to _______________ ?

A. provide robust structure
B. convert kinetic energy of air into pres-sure energy
C. collect more air
D. beautify the shape
E. none of the above

The weight per horse power ratio for gas. turbine as compared to I.C. engine and steam turbine is________________?

A. higher
B. same
C. lower
D. uncomparable
E. unpredictable

The blades of gas turbine are made of_________________?

A. stainless steel
B. mild steel
C. carbon steel
D. high alloy seel
E. high nicket alloy (neimonic)

Fighter bombers use following type of engine __________________?

A. turbo-jet
B. rocket
C. turbo-propeller
D. ram-jet
E. pulsojet

The following property is most important for material used for gas turbine blade___________________?

A. fatigue
B. toughness
C. creep
D. corrosion resistance
E. bulk modulus

The specific output per kg mass flow rate of a gas turbine (having fixed efficiencies of compressor and turine and fixed higher and lower temperature) with increase in pressure ratio will___________________?

A. increase first at fast rate and then slow
B. decrease continuously
C. increase first at slow rate and then fast
D. first increase, reach maximum and then decrease
E. none of the above

The effective power of gas turbines is increased by adding the following in compressor__________________?

A. ammonia and water vapour
B. nitrogen
C. carbon dioxide
D. hydrogen
E. none of the above

Air-fuel ratio in a jet engine will be of the order of__________________?

A. 15: 1
B. 10: 1
C. 20: 1
D. 60: 1
E. 100: 1

In jet engines the compression ratio__________________?

A. Varies linearly to the speed
B. varies as square root of the speed
C. varies as square of the speed
D. varies as cube of the speed
E. is constant irrespective of variation in speed

Fluid Mechanics Mcqs – Mechanical Engineering Mcqs

High air-fuel ratio is used in gas turbines______________________?

A. to save fuel
B. to increase the efficiency
C. to increase the output
D. to reduce the exit temperature
E. none of the above

In which case the air-fuel ratio is likely to be maximum _________________?

A. 4-stroke petrol engine
B. 2-stroke engine
C. 4-stroke diesel engine
D. multi-cylinder engine
E. gas turbine

Reheating in gas turbine results in___________________?

A. decrease of thermal efficiency
B. decrease of work ratio
C. decrease of work ratio
D. both A. and B. above
E. both B. and C. above

Work ratio of a gas turbine may be improved by f____________________?

A. increasing the turbine work
B. increasing the compression work
C. decreasing the compression work
D. decreasing the turbine work
E. A. and C. above

In the aircraft propellers __________________?

A. the propulsive matter is caused to flow around the propelled body
B. its functioning does not depend on presence of air
C. propulsive matter is ejected from within the propelled body
D. all of the above
E. none of the above

Work ratio of a gas turbine plant is ratio of______________________?

A. net work output and work done by turbine
B. work done by turbine and heat supplied
C. net work output and heat supplied
D. work done by turbine and net work output
E. actual/heat drop and isentropic heat drop

The main purpose of reheating in gas turbine is to__________________?

A. reduce turbine size
B. increase temperature
C. increase power output
D. increase speed
E. increase pressure ratio

Gas turbine cycle with Regenerator __________________?

A. increases thermal efficiency
B. decreases heat loss is exhaust
C. allows high compression ratio
D. allows operation at very high altitudes
E. permits high moisture content fuel to be used

Reheating in multistage expansion gas turbine results in____________________?

A. reduction in compressor work
B. high thermal efficiency
C. decrease of heat loss in exhaust
D. maximum work output
E. none of the above

Maximum temprature in a gas turbine is of the order of COMPRESSORS, GAS TURBINES AND JET ENGINES______________________?

A. 2000°C
B. 2500°C
C. 1500°C
D. 1000°C
E. 700°C

In air breathing jet engine, the jet is formed by expanding__________________?

A. solids
B. gases
C. liquid
D. plasma
E. highly heated atmospheric air

The efficiency of jet engine is__________________?

A. same at all altitudes
B. higher at high altitudes
C. higher at ground
D. higher at high speed
E. lower at low speed

For speed above 3000 km/hour, it is more advantageous to use____________________?

A. propellers
B. ram-jet engine
C. turbo-jet engine
D. rockets
E. hydraulic jet propulsion

The compression ratio in a jet engine varies proportional to ____________________?

A. altitude
B. speed
C. speed
D. Vspeed
E. does not Vary

The efficiency and work ratio of a gas turbine plant can be increased by _____________________?

A. using mulit-stage compressor with mfercooler
B. injecting water in/around combustion chamber
C. adding heat exchanger
D. reheating the air after partial expansion in the turbine
E. all of the above

Turbofan engine employs ____________________ ?

A. no air stream
B. two or more air streams
C. one air stream
D. solid fuel firing
E. rocket principle for its operation

Which of the following plants is smallest and lightest for genrating a given amount of power__________________?

A. petrol engine
B. steam power plant
C. diesel engine’
D. solar plant
E. gas turbine plant

Pressure ratio in gas turbines is the ratio of ____________________?

A. pressures across the turbine
B. highest pressure to exhaust pressure
C. inlet pressure to exhaust pressure
D. compressor pressure ratio
E. none of the above

In turbo fan engine, the jet velocity as compared to turbo-jet engine is_________________?

A. less
B. same
C. more
D. may be less or more depening upon speed
E. none of the above

A simple turbo-jet engine is basically_________________?

A. chemical rocket engine
B. gas-turbine engine equipped with a propulsive nozzle and diffuse*
C. a propeller system
D. ram-jet engine
E. none of the above

Ram-jet engine__________________?

A. requires no air for its operation
B. is not self-operating at zero^flight speed
C. is self-operating at zero flight speed
D. produces a jet consisting of plasma
E. none of the above

The compression ratio in a gas turbine is of the roder of____________________?

A. 5 : 1
B. 3 : 1
C. 8 : 1
D. 12 : 1
E. 20 : 1

The working fluid in ai turbine is___________________?

A. in three phases
B. in two phases
C. in a single phase
D. in the form of air and water mixture
E. gas and no air

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______________?

A. Vi=V0B
B. U,<V0
C. Vt>V0
D. V,= U0
E. Vri=Vm

In jet engines the products of combustion after passing through the gas lurbine are discharged into_______________?

A. back to the compressor
B. atmosphere
C. discharge nozzle
D. vacuum
E. none of the above

Pick up the false statement ?

A. gas turbine is a self-starting unit
B. gas turbine does not require huge quantity of water like steam plant
C. overall efficiency of gas turbine plant is lower than that of a reciprocating engine
D. exhaust losses in gas turbine are high due to large mass flow rate
E. gas turbine can be easily started and stopped and thus is best suited for peaking demands

Pick up the correct statement?

A. air-fuel ratio in a gas turbine is 100 : 1
B. gas turbine uses same working fluid over and over again
C. closed cycle gas turbine is an I.C engine
D. ideal efficiency of closed cycle gas turbine plant is more than carnot cycle efficiency
E. thrust in turbo-jet is produced by nozzle exit gases

Pick up the wrong statement ?

A. pulsojet requires no ambient air for propulsion
B. turbine drives compressor in a burbojet
C. ramjet-engine has no turbine
D. bypass turbo-jet engine increases the thrust without adversely affecting, the propulsive efficiency and fuel economy
E. propeller is an indirect reaction device

Pick up the correct statement ?

A. gas turbines use both air and liquid cooling
B. gas turbines have their blades similar to steam turbine
C. gas .turbine’s blade will appear as impulse section at the hub and as a reaction section at tip
D. large gas turbines use radial inflow turbines
E. all of the above are correct.

Choose the correct statement ________________?

A. gas turbines have flat efficiency at part loads
B. gas turbine is capable of rapid start up and loading
C. gas turbine requires lot of cooling water
D. gas turbines have high standby losses and require lot of maintenance
E. gas turbines can be used to generate power only

Pick up the wrong statement ?

A. axial flow compressors have high capacity and efficiency
B. axial flow compressors are more stable than centrifugal type compressors but not as efficient
C. large gas turbines employ axial flow compressors
D. axial flow compressors have instability region of operation
E. centrifugal compressors are used mainly on low flow pressure ratio gas turbines

Pick up the correct statement ?

A. gas turbine uses low air-fuel ratio to develop the high thrust required
B. gas turhine uses high air-fuel ratio to reduce outgoing temperature
C. gas turbine uses low air-fuel ratio to economize on fuel
D. all of the above
E. none of the above

Pick up the wrong statement ?

A. centrifugal compressors deliver prac-tically constant pressure over a considerable range of capacities
B. centrifugal compressors have a wider stable operating range than axial flow compressors
C. Axial flow compressors have a sub-stantially constant delivery at variable pressures
D. axial flow compressors are bigger in diameter compared to centrifugal type
E. axial flow compressors apt to be longer as compared to centrifugal type

Latest Competitive Mechanical Engineering MCQs – Compressors, Gas Turbines and Jet Engines MCQs

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