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GAS TURBINES AND JET PROPULISION

BIT BANK

UNIT 1

1) Around the turn of nineteenth century the most important prime mover

was( )

a)gas turbines

b)diesel engines

c)steam turbines

d)gasoline engines

2) arly aircraft engines use ()a)gas turbines

b)gasoline engines

c)diesel engines

d)steam turbines

!) The gas turbine was invented by

a)"ohn barber

b)brayton

c)otto

d)At#inson

$) arly designs of the gas turbine were unsuccessful due to

a)low e%ciency of the compressorb) low e%ciency of the turbine

c)combustion temperature limitation

d)all of the above

&) 'eciprocating engines are preferred over gas turbines because of()a) high

reliability

b)high power to weight ratio

c)all of the above

d)none of the above

) A simple open cycle gas turbine power plant consists of ()a) turbine combustion chamber * heat e+changer

b) turbine combustion chamber * charge cooler

c) turbine combustion chamber * compressor

d) turbine compressor * heat e+changer



,) The combustion in a gas turbine is at ( )a)constant pressure

b)constant volume

c)partly constant pressure partly constant volume

d)none of the above

-) The performance of a simple gas turbine depends on ( )a)e%ciency of the compressor

b) e%ciency of the turbine

c) e%ciency of the compressor * turbine

d) none of the above

.) The pressure ratio of the modern gas turbine power plant is ( )

a) & / 1

b)10 / 1

c) 1& / 1

d)20 / 1

10) The highest turbine inlet temperature is a)1000#

b)1200#

c)1&00#

d)1-00#

11) Thermal e%ciency of a gas turbine plant as compared to 3iesel engine

plant is 4444444445a) 6oreb) 7ess

c) 8uald) None of the above12) Thermal e%ciency of closed cycle gas turbine plant increases by

44444444444445a) 6oreb) 7essc) 8uald) None of the above

1!) 9ith the increase in pressure ratio thermal e%ciency of a simple gas

turbine plant with :+ed turbine inlet temperature :rst 444444444 and

then4444444 a) Increases and decreases

b) 3ecreases and increasesc) all of the aboved) None of the above

1$) The thermal e%ciency of a gas turbine cycle with ideal regenerative

heat e+changer is 444444445a) 6oreb) 7essc) 8ual



d) None of the above

1&) In a two stage gas turbine plant reheating after :rst stage 44444444

thermal e%ciency5a) Increasesb) decreasesc) Increases and decreasesd) None of the above

UNIT ;II

21)<erformance of an ideal cycle power plant pertains to

a)wor# input

b)e%ciencyc)speci:c fuel consumption

d)all of the above

225 A simple ideal cycle consists of

a)two adiabatic * two isentropic

b) two adiabatic * two isothermal

c) two constant pressure * two isothermal

d) two isentropic * 1 constant pressure * 1 constant volume

2!5 =or the ma+imum speci:c output for any given value of t theoptimum pressure ratio is given by

a) c > t

b) c > t2

c) c > ?t

d)c > 1@t



2$5 <ower output of simple cycle is a function of

a) only pressure ratio

b) only temperature ratio

c) both pressure * temperature ratio

d)all of the above

2&5 The e%ciency of the ideal cycle is a function of

a)only the of the wor#ing fluid

b) only pressure ratio

c) both pressure ratio *

d) inlet temperature of the turbine

25 6a+imum power output is achieved for a simple ideal cycle with respect

to pressure ratio when

a)outlet temperature of compressor is e8ual to outlet temperature

b) outlet temperature of compressor is lower than outlet temperature

c) outlet temperature of compressor is higher than outlet temperatured)it has nothing to do with outlet temperature

2,5 9hen a heat e+changer is added to an ideal simple cycle

a)power output decrease but the e%ciency increases

b) power output increase but the e%ciency decreases

c)both remain the same

d) power output remains the same but the e%ciency increases

2-5 =or better performance an ideal heat e+change cycle should be operated with

a) lower t * higher r

b) higher t * higher r

c) lower r * higher t

d)r * t should be the same

2.5 6ulti stage compression with inter cooling * multi stage e+pansion with

reheating improves

a)e%ciency

b)power output

c)both power output * e%ciency


!0) An ideal cycle with reheat inter cooling * heat e+changer will increase

a)e%ciency

b)power output



c)both power output * e%ciency


15 A "et engine has 4444444

25 In "et propulsion power unit inlet duct of diverging shape is used for

converting #inetic energy of air into pressure energy True@=alse

!5 In a "et engine the compression varies as the s8uare of the speed

True@=alse

$5 In a "et engine the air fuel ratio is44444444

&5 The e%ciency of a "et engine is higher at44444444

5 The thrust of a "et propulsion power unit can be increased by 444444444444

, 5 A simple turbo "et engine is basically a gas turbine engine e8uipped witha propulsive noBBle and diCuser True@=alse

-5 In a "et propulsion unit the products of combustion after passing through

the gas turbine are discharged into 44444444444

.5 In open cycle turbo "et engines used in military aircraft reheating the

e+haust gas from the turbine by burning more fuel is used to increase

the4444444444

105 A roc#et wor#s with ma+imum overall e%ciency when air craft velocity

is4444444444 the "et velocity5

UNIT;III

1)The ma"or application of gas turbine is for

a)air craft application

b)automotive application

c)7ocomotive application

d)gas pumping

2) Dombustion in a gas turbine combustion system is at

a)constant;volume

b)constant;pressure

c)constant;temperature

d)constant enthalpy!) Acceleration of the reaction in a gas turbine combustion system is brought

about by



a)bombardment of nucleus

b)chain brea#ing

c)chain branching

d)none of the above$) Air;fuel ratio in a gas turbine in the range of

a)20;!0b)!0;$0

c)$0;0

d)0;100&) The isentropic e%ciency of the modern compressor is

a)&E

b),&Ec) -&E

3) .0E

) The isentropic e%ciency of a turbine is de:ned as the ratio of a) Actual wor# output@isentropic wor# output b) Isentropic wor# output @actual wor# output

c) actual wor# input@isentropic wor# input

d) isentropic wor# input@actual wor# input,) The eCectiveness of the modern heat e+changer is

a)>&&E

b)>&E

c)>,&E

d)>.0E-) The wor# ratio is de:ned as

a)9ry F9e@9ryb)1;9c@9t

c)9in@9t

d)all of the above.) The mechanical loses are accounted by mach on

a)compressor side

b)combustion chamber side

c)heat e+changer side

d)turbine side10) Dycle e%ciency can be de:ned as

a)9a;9a@f+Dv

b)9n@f+Dvc)!00@-fc+Dv

d)any of the above e8uation

15 The ma+imum combustion pressure in gas turbine is4444 as compared

to I5D engine5



25 In gas turbines the wor# input with intercooling is 444444 the wor# input

with no intercooling

!5 The ma+imum temperature in a gas turbine is444444444445

$5 A closed cycle gas turbine gives 444444444444444 e%ciency as comparedto an open cycle gas turbine5

&5 'eheating in a gas turbine 444444444 the thermal e%ciency5

5 'eheating in a multi stage e+pansion gas turbine 4444444444

compressor wor#5

,5 A regenerator in a gas turbine improves 444444444444 e%ciency5

-5 The compression ratio in a gas turbine is 44444445

.5 The ratio of the net wor# obtained from the gas turbine plant to theturbine wor# is #nown as 44444444444444444445

105 Gigh air fuel ratio in a gas turbines 44444444444 e+haust temperature5

UNIT;IH

1) =or a constant value of npc(say -&E) nc

a)increases with increase in pressure ratio

b)decreases with increase in pressure ratio

c)remains constant with increase in pressure ratiod)none of the above

2) A gas turbine cycle can be operated

a)only as an open;cycle arrangement

b)only as a closed;cycle arrangement

c)both as open Fcycle and closed Fcycle arrangement

d)none of the above!) Adding heat e+changer to a simple ideal cycle

a)improves wor# input

b)reduces wor# output

c)improves e%ciency

d)improves both wor# output and e%ciency

$) The speci:c weight of a gas turbine power plant is



a)&0#g@w

b)20#g@w

c)100#g@#9

d)-0#g@#9

&) The selection of the wor#ing medium of a close;cycle gas turbine power plant

is based on

a)the availability and cost

b)non;e+plosive and non F corrosive properties

c)high speci:c heat and speci:c heat ratio

d)all of the above) The life of an industrial gas turbine without ma"or over haul is

a)1205000h

J)12000h c)1200h

d)120h

,) The life of a aircraft gas turbine without ma"or overhaul is

a)1205000h

b)12000h

c)1200h

d)120h

-) The overall e%ciency of a gas turbine engine compared to reciprocating

engine for same power output a)more

b)less

c)same as reciprocating engine

d)none of the above

.5 Intercooling in gas turbine

A) decreases net output but increases thermal e%ciency

J) increases net output but decreases thermal e%ciency

D) decreases net output and thermal e%ciency both

3) increases net output and thermal e%ciency both

105 In the aircraft propellers

A) the propulsive matter is e"ected from within the propelled body

J) the propulsive matter is caused to Kow around the propelled body



D) itLs functioning does not depend upon the presence of air

3) none of the above

115 Mnly roc#et engines can be propelled to space because they are 4444444

engines5

125 The basic principal of the roc#et propulsion is the same as that of "et

propulsion5 yes@ no

1!5 In a gas turbine air is obtained from the atmosphere and compressed in

an air compressor5 true@ false

1$5 The velocity of air entering in a roc#et is4444444 as compared to an aircraft5

1&5 The mass of gas turbine per #9 developed is about 444444444 as that of

an I5D engine5

15 A closed cycle has turbine wor#s on 444444444445

1,5 An open cycle gas turbine wor#s on the same cycle as that of a closed

cycle gas turbine5 true @ false

1-5 A closed cycle gas turbine consists of a44444444445

1-5 In a closed cycle has turbine the air is compressed 4444444444444

1.5 The gas in cooling chamber of a closed cycle gas turbine is cooled at

444444444444444

205 A gas turbine used in air craft should have low weight and small frontal

area5 true @ false

UNIT - 5

15 A "et engine has

a no propeller b propeller at front c propeller at bac# d propeller on top

25 The e%ciency of a "et engine is higher at



a low speed b high speed c low altitude d high altitude

!5 The thrust is calculated as

a v "et ; va b ma(v "et ; va ) c 2va@ v "et va d ma(v "et ; va )va

$5 The thrust of a "et engine can be increased by

a In"ecting water into the compressor b reheating gas after turbine

c in"ecting methanol into compressor d all the above

&5 A turboprop is preferred to a turbo"et engine because

a it has high propulsive e%ciency at high speed

b it can Ky at supersonic speed

c it can Ky at high altitude

d it has high power for ta#e oC

5 In a "et propulsion unit the product of combustion after passing through the gas

turbine are discharged into

a atmosphere

b vacuum

c discharge noBBle

d bac# to compressor for ne+t cycle

,5 In a turbo"et engine used in military aircraft the e+haust gas from the turbine is

reheated by burning of additional fuel to increase the

a thrust and range of aircraft

b e%ciency of the engine

c both a and b

d none of the above

-5 In an ideal turbo"et engine after heat addition to compressed air the wor#ing

substance is e+panded in

a e+it noBBle at constant pressure

b e+it noBBle at isentropic manner



c turbine blades at constant temperature

d turbine blades in isentropic manner

.5 A "et engine uses o+ygen for combustion of its fuel form

a surrounding air b o+idiBer c propellent d none of the above

105 In a turbo"et engine the diCuser is :tted at

a nose b after compressor c after turbine d before turbine

115 A ram"et engine is the simplest type of engine5

125 3uring wor#ing of ram"et engine air from atmosphere enters into the diCuser at

.

1!5 'am"et engine wor#s on the principal of cycle5

1$5 The ideal cycle of ram"et engine consists of processes5

1&5 The operating speed of a ram"et should be at least mph5

15 'am"et engine operates continuous combustion due to absence ;;;;;;;;;;;; .

1,5 The cycle pressure ratio of an ram"et engine is dependent on velocity5

1-5 In aircraft fuel can be used directly5

1.5 A ram"et engine is an propulsion device5

205 Ocram"et engine is employed for the speed5

UNIT 6

15 The propulsive e%ciency is de:ned as

a H "et ;Ha2 @ 2Ha b 2Ha @ H "etHa c 2Ha @ H "et;Ha d H "etHa @ 2Ha

25 A roc#et engine receives o+ygen for combustion of fuel from

a surrounding air

b compressed atmospheric air

c o+idiBer o board

d none of te above

!5 A roc#et engine can be propelled to space because



a it generates very high thrust

b it has high propulsive e%ciency

c it can wor# on several fuels

d it is not air breathing engine

$5 A roc#et engine operates only in P

a rati:ed atmosphere b vacuum

c atmosphere d all the above

&5 9hen a roc#et is used as weapon with a warhead as payload then it is called a

a "et b turbo"et c missile d turbo propeller unit

5The propellant for a roc#et engine is a

a "et carried by the roc#et only

b o+idiBer carried by the roc#et only

c fuel and o+idiBer carried by the roc#et only

d none of the above

,5 Thrust in a roc#et is generated by a "et of

a air ta#en from the atmosphere

b e+haust gases coming out at high velocity at the rear

c compressed air

d none of the above

-5 The thrust is calculated as

a v "et ; va b ma(v "et ; va ) c 2va@ v "et va d ma(v "et ; va )va

.5 A turboprop is preferred to a turbo"et engine because

a it has high propulsive e%ciency at high speed

b it can Ky at supersonic speed

c it can Ky at high altitude

d it has high power for ta#e oC



105 The wor# ratio is de:ned as

a)9ry F9e@9ry

b)1;9c@9t

c)9in@9t

d)all of the above

115 A engine facilitates high amount of thrust for a re8uired time in a

speci:c direction5

125 'oc#et has low with higher consumption of propellant5

1!5 Gigh thermal stresses are produced by the chamber5

1$5 In roc#et engines thrust developed per unit area is .

1&5 In roc#et engines speci:c impulse is 5

15 The e%ciency of roc#et is very high at speeds51,5 The mass of roc#et gradually decreases during the operation due to the

and outKow of e+haust gases5

1-5 'oc#et engine is a breathing engine5

1.5 The hybrid roc#et engines uses a combination of and propellant5

205 The hybrid roc#ets are used to propel targets in testing5

UNIT 7

1)The ma"or application of gas turbine is for

a)air craft application

b)automotive application

c)7ocomotive application

d)gas pumping

11) Dombustion in a gas turbine combustion system is at

a)constant;volume

b)constant;pressure

c)constant;temperatured)constant enthalpy

12) Acceleration of the reaction in a gas turbine combustion system is

brought about by

a)bombardment of nucleus

b)chain brea#ing



c)chain branching

d)none of the above1!) Air;fuel ratio in a gas turbine in the range of

a)20;!0

b)!0;$0

c)$0;0d)0;100

1$) The isentropic e%ciency of the modern compressor is

a)&E

b),&Ec) -&E

3) .0E

1&) The isentropic e%ciency of a turbine is de:ned as the ratio of a) Actual wor# output@isentropic wor# output b) Isentropic wor# output @actual wor# output

c) actual wor# input@isentropic wor# input d) isentropic wor# input@actual wor# input1) The eCectiveness of the modern heat e+changer is

a)>&&E

b)>&E

c)>,&E

d)>.0E1,) The wor# ratio is de:ned as

a)9ry F9e@9ry

b)1;9c@9t

c)9in@9td)all of the above1-) The mechanical loses are accounted by mach on

a)compressor side

b)combustion chamber side

c)heat e+changer side

d)turbine side1.) Dycle e%ciency can be de:ned as

a)9a;9a@f+Dv

b)9n@f+Dv

c)!00@-fc+Dv

d)any of the above e8uation

115 The aerodynamic force produced by the wing movement through air is #nown

as force5

125 The force produced by the propeller or a roc#et in the direction of a+is of the

propeller shaft is #nown as 5



1!5 As the thrust decreases the speed of the Kight .

1$5 9hen the thrust and drag are e8ual a air speed is maintained5

1&5 ;;; ;;; roc#et is a type of roc#et employed for very long distance space travell5

15 multi staging roc#ets consists of stages5

1,5 IN multi staging roc#ets propellant tan#s are heavier than;;;;;;;;;;;;;

1-5 Geat transfer distribution plays a vital role in eCective functioning of the

5

1.5 In an under e+panded noBBle the e+it pressure of a discharging Kuid is greater

than the pressure205 In an over e+panded noBBle the e+it pressure of a discharging

Kuid is lower than the --------- pressure5

UNIT 8

1) The gas turbine was invented by

a)"ohn barber

b)brayton

c)otto

d)At#inson

1,) arly designs of the gas turbine were unsuccessful due to

a)low e%ciency of the compressor

b) low e%ciency of the turbinec)combustion temperature limitation

d)all of the above

1-) The highest turbine inlet temperature is a)1000#

b)1200#

c)1&00#

d)1-00#

$) =or better performance an ideal heat e+change cycle should be operated

with

a) lower t * higher r

b) higher t * higher r

c) lower r * higher t

d)r * t should be the same



&)Air;fuel ratio in a gas turbine in the range of

a)20;!0

b)!0;$0

c)$0;0

d)0;100

) The isentropic e%ciency of the modern compressor is

a)&E

b),&E

c) -&E

,) The life of an industrial gas turbine without ma"or over haul is

a)1205000h J)12000h c)1200h d)120h

-) The life of a aircraft gas turbine without ma"or overhaul is

a)1205000h

b)12000hc)1200h

d)120h

.) A gas turbine cycle can be operated

a)only as an open;cycle arrangement

b)only as a closed;cycle arrangement

c)both as open Fcycle and closed Fcycle arrangement

d)none of the above

10) Adding heat e+changer to a simple ideal cycle

a)improves wor# input

b)reduces wor# output

c)improves e%ciency

d)improves both wor# output and e%ciency

115 In cryogenic propellant the propellant which is in li8uid states is at

temperature5

125 In cryogenic propellant the propellant which is in gaseous states is at

temperature5

1!5 Nuclear roc#et engines can produce much larger velocities than

roc#et engine for a given weight5



1$5 In nuclear :ssion reactor heat is generated by the :ssion of in

solid reactor material5

1&5 nuclear :ssion reactor nuclear energy is produced to heat up the

5

15 The gas pressuriBation system both and tan#s are

pressuriBed5

1,5 In plasma roc#et engine the propellant is forced between and

to produce thrust form the e+pansion of plans in the noBBle5

1-5 In plasma roc#et engine energy is used for heating the propellant

and to generate thrust in the roc#et5

1.5 The ratio of the net wor# obtained from the gas turbine plant to the

turbine wor# is #nown as 44444444444444444445

205 Gigh air fuel ratio in a gas turbines 44444444444 e+haust temperature5



1.)

a)

b)

c)

d)

20)

a)

b)

c)d)

21)

a)

b)

c)



d)

22)

a)

b)

c)d)

2!)

a)

b)

c)

d)

2$)

a)

b)c)

d)

2&)

a)

b)

c)

d)2)

a)

b)

c)

d)

2,)

a)

b)

c)

d)2-)

a)b)

c)

d)2.)





a)

b)

c)

d)

a)

b)

c)

d)

a)b)

c)

d)

a)



b)

c)

d)

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