7/26/2019 Jet Engine System Class Test -2 2015

1/2

CLASS TEST-2 SUBJECTSJET ENGINE SYSTEMBATECH-6 SEM.-IV Total Marks-20Date-6!0" !206 TIME-60 MINUTES

1 In gas turbine engines, a condition of normal light off but with

r.p.m. remaining at some low value rather than increasing to

the normal idle r.p.m. This is often the result of insufficient

power to the engine from the starter.a. Hung start.b. Hot start.c. False start.#. Bot$ %a& a'# %(&.

2 When temperature limitations are eceeded during start,

possibl! damaging the engine"s hot section. If the condition

continues unchec#ed, a fire ma! result. Hot starts ma! be

caused b! improper pilot action $introducing fuel before

reaching the proper motoring rpm%, a failure of the fuel

controller or fuel no&&le.a. Hung start.). Hot start.

c. False start.d. 'oth $a% and $c%.

( What t!pe of lubrication s!stem used in gas turbine engine)a *ressure relief valve s!stemb Full flow s!stem( Bot$ %a& * %)& are (orre(td +one of the above

Which t!pe of valve s!stem controls oil flow b! limiting the

pressure from the oil pump to the given value)a +ress,re rele /al/e sste1b Full flow s!stemc 'oth $a% - $b% are correctd +one of the above

Which t!pe of s!stem pressure changes with /*0 change

and when the bearing vent cavities contain high air pressure)a *ressure relief valve s!stem) ,ll lo3 sste1c 'oth $a% - $b% are correctd +one of the above

What is the primar! function of the lubrication s!stem)a To suppl! oil to the various parts within the engine which

are subected to friction loads from engine rotation and

heat loads from the gas path.b To suppl! oil under pressure along the main rotor shaft

and to the gearbo to reduce friction to cool and to clean.( Bot$ %a& * %)& are (orre(td +one of the above

3 0T45 $/egarding lubricating fluids %a 6ubricating fluids fill all surface irregularities providing oil

film which slide against each other and prevent metal to

metal contact.b The primar! purpose of an engine lubricant is to reduce

friction between moving parts.c The secondar! purpose of an engine lubricant is to act as

a cushion between metal parts to cool and to clean.# All o t$e a)o/e.

7 Which t!pe of lubricants is used in gas turbine engine)a 5!nthetic lubricants.

b *etroleum lubricants.( Bot$ %a& * %)& are (orre(td 8nl! $a% is correct

9 What are desirable characteristic of s!nthetic lubricants.a 6ow volatilit!.b :s $a% and high flash point.c :s $b% and low pour point.# As 4 a'# lo3 la(5,er a'# (oke #eosts.

1; What are desirable characteristic of s!nthetic lubricants.a High volatilit!.b 6ow flash point.( A't-oa1'7 5,alt.d High pour point.

11 What are desirable characteristic of s!nthetic lubricants.a High volatilit!.b 6ow flash point.

c High pour point.# H7$ /s(ost '#e8.

12 0T45 $/egarding oil tan#s%a 8il tan#s epansion space of 1; < must be provided.b 8il tan# scupper must be provided to carr! spilled oil

drain point on an engine.( Bot$ %a& * %)& are (orre(td 8nl! $b% is correct

1( 5:= means in lubricant oil >a 5ociet! of association engineers.) So(et o a,to1ot/e e'7'eers.c 5ociet! of association engine.d 5ociet! of automotive engine.

1 5:= number indicates in lubricants oil

a Vs(ost 7ra#e.b ?ualit! of oil.c 'oth $a% - $b% are correctd +one of the above

1 5.@.5 means in oil grade>a Sa)olt - U'/ersal se(o'#.b 5ociet! > @niversal second.c 5econd > @niversal 5ociet!.d :ll of the above

1 5:= W>2; means in oil grade>a 8il when cold will have the viscosit! of 5:= .b +ormal operating temperature will thin out no more th

5:=>2;.c 8nl! $b% is correct.

# Bot$ %a& * %)& are (orre(t

13 Which t!pe of oils does not have 5:= rating indicating

viscosit!)a S't$et( l,)r(a'ts.b *etroleum lubricants.c 'oth $a% - $b% are correct

17 Which t!pe of oils has #inematic viscosit! rating in

centisto#es)a S't$et( l,)r(a'ts.b *etroleum lubricants.c 'oth $a% - $b% are correct

1

7/26/2019 Jet Engine System Class Test -2 2015

2/2

d :ll of the above.

19 What are the determined b! measuring the viscosit! change

when a liAuid lubricant is heated to different temperature.a 5!nthetic lubricants.b *etroleum lubricants.( Vs(ost '#e8.d :ll of the above.

2; :5T0 means>a :erospace societ! of testing material.) A1er(a' so(et o test'7 1ateral.c :erospace science of testing material.d :ll of the above.

21 How is determine viscosit! inde when the sa!bolt universal

viscosit! is #nown.a Biscometer.) No1o7ra$.c 0onograph.d 5!smograph.

22 T!pe >1 lubricant isa. MIL-L-9:0:b. 0I6>6>2(99c. 0I6>6>377;d. 0I6>6>2(99

2( 0T45 $/egarding viscosit! inde%a The higher the viscosit! inde of the oil, the less

tendenc! it has to thin out when heated.b Biscosit! of oil is given as #inematic viscosit! in

centisto#es from a #inematic viscometer rather than in

5.@.5 units from a sa!>bolt viscometer.c +omograph reveals is a basic Aualit! of the oil.# All o t$e a)o/e.

2 Biscosit! of lubricant oil is measured b!

a Vs(os1eter.b Biscometer.c 0onograph.d C>meter.

2 Which t!pe of centisto#es oil is used in a turboprop engine

where high gear loading.a Three.) Se/e'.c Five.d Four.

2 Which t!pe of centisto#es oil is used in a turboet and turbofan

engine)

a Three.b 5even.( /e.d Four.

23 T!pe >2 lubricant isa. 0I6>6>37;7). MIL-L-2"6;;c. 0I6>6>377;d. 0I6>6>2(99

27 4olor of s!nthetic oils of t!pe>1 and t!pe>2 isa. 5traw colored when new.b. Dar#en over time in service.c. 8nl! $a% is correct.#. Bot$ %a& a'# %)& are (orre(t.

29 4olor of s!nthetic oils of t!pe>( isa. Sl7$tl #arker 3$e' 'e3.b. Dar#en over time in service.c. 8nl! $b% is correct.d. 'oth $a% and $b% are correct.

(; 0T45 $/egarding centisto#es values%a Three centisto#es oils are approimatel! eAual to 5:=b Five centisto#es oils are approimatel! eAual to 5:=>

1; multi>viscosit! oil.c 5even centisto#es oils are approimatel! eAual to 5:

W>2; multi>viscosit! oil.# All o t$e a)o/e.

(1 Which device is used for good contaminant indicator of en

wear when counted)a. Se(tro1eter.b. Biscometer.c. 0onograph.d. C>meter.

(2 Which t!pe of bearings ta#es aial and thrust load)a. /oller bearingb. 'all bearingc. Deep grob baring#. Bot$ %a& a'# %)& are (orre(t

SUBJECTIVE