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MECHNICAL ENGINEERING J ·c==== -~==~

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PAPER·II

When can a pie-tometer be not used for pressure mensuremcnt in pipes'' a. The pressure difference fs low b, The velocity is high c. The lluid in ~1e pipe [sa gas d The Outd in the pipe is highly 1·iscous Wbtcll phenomenon will occur 1\ben lhe val ue Bl the discharge end of a pipe connected to a resen oir tS sudden!) closed1 a, Cavitation b Erosion c 1-lrunmenng

d. Surging For linear distri bmion of velocJty 111 the boundary layer on a Oat plate. "'hat is the milo of displacement thickness I o•) to th~ boundary layer thickness (5)'1

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5

Consider the foll omng Statements

I For ad11evmg dynamic in model studies on ships, Froude numbers are equated.

2 Reynolds number should be equated for studies on an aerofoil for dynamic similarfly.

3 In model studies on a. spillway. the ratio of ~Vidth lo height fs equaled for kinematics stmilarity.

What of the statements g•ven abo1 e are correct'/ a 1.2and3 b land2

c. 2 aml3 lL t and3

5

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7_

How is the beSI hydmnlic channel cross­section defined? a. ·n1e sect.ion '' i th minimtun roughness

coefficient b. The section that has n ma.' urn area of

a g1 vcn 1!011

c. The section that bas a miuimum wetted peri me(er

d The section that has maximum welled area

Constder the following statements: In the case of convergent noule for compressible llow_ I. No shock wa1•e c'111 occur at, any

pressure ratio, 2, No expansion wave can occur below a

certain pressure ratio

3 EJ>pansion wme can occur below a CL>rtain preSl;ure ratio.

4 Shoc.k wave can occur ubove a certain pressure ratio.

Which of the follo11ing statements gi\etl abo,'e are- correct'! a I and 2

b. 3 and 4 c. I and 3 d. 2 and 4 Which one of ~1e foiiO\Ving is the condition for s table equilibrium for a Ooating body? a. Tile 1ne1 cemer coutcides wtlh 1he

centre of gra\'ity

b. The met centre is below the centre of gnwrt~

c. The met centre ls nbove the centre of gra\'11)'

d. TI1e centre or buoyancy is below the centre of gra\'lty

Whtch of ~1e rollo11 ing assumptioru; /conditions ure true in the case of Rayle1yh no" ·1 I. Perfect gas 1. Constant area duct.

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3. Steady on~dimension~l rea l !low. ~ . He•ttromd'er during the flow. Select Ute ~ol'\'eet Pnswer nsln~ the code given below:

••• 1..2 ·'"" 3 h. 2.3 oml4 Ct 1, 3::m<J4 d. 1 . 2:md~

If the croos-section of a nozzJe is illcreasing ill the directi<m of now ;,, supersonic !low tlton i.tt the do\Vtllltrc•tn direction a~- .Both pressure a.nd velocity wiU

increase

h. !3oth pre.•snre and vdoQity will decrease

c. Pressure wlll inorease but velooity wiiJ d~-else

tl. Pl'llssull> will d..:I'C3!sc but velocity will ittcrc3:se.

Tbe entropy of a mix tun: of ideal gas.:s ], the •um of the entropie< of c.onstinoent• evo tnated •t:

~. 'h:mperature :md p~sure of t,h.,

mixtute b. Tcmpcruturc of lite nu,,-rurc •nd Ute

purtial pressure oflhc coustitucnt.s c. Temperature ootd volume ol' dtc

mL-<ture d. PrcMSure Pnd volume of dte mixture A pa•sive method to k<>CJ> dtc bou•c comll>rta~l~ warm by sot~r conditinmng in t~•ld clintalic C<ll)d it ion i< 1<1 puillt o.e : a. Eastern •~nil of the huuse b) black

JWiul Otl its outer .sitlt. b. E:ustcru w>JI of t11o 1wu.,e by l>Jlck

l)ajnts ori its iHner ~ide c. Southern wull uf the house by hl:lck

paiJll on its ou1er ~ide d. Southern woll of the house hy bl•ck

paint on it.s inn~-r •ide>. An air-conditioned room of volume 10 mJ l1os infiltration of air equivalent to 3 Aif chan~os per hour. Dcn•ity of air is 1.2 kg/m • specitic hen! Cp U. 1 kJt1cg K and temper•,ture differeuce betweeu I'OOUI aud :unbicnl Air C. '20 K. \VIul is tbc ••nsiblo heot load duo to infiltrated air? a. 61) ld/hour b. 12 kJ/hour

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c. 0.45 k\V d. 0.1kW Oo wrucb fnctor(s), does the. hc3l lost by the humnn body m the process of rndi.tion dcpcm" • TO.nper:u.ure only b. Teln]><:rature ontl air motion c. Temperature oo<l rotative humidity d. Relotive h nmidily and air motion

Wh1cb one of tlle to llowinj! statement• ls C(;lQ"CCt1

Tit~ optimum effective Lempe•~•ture for hunwn comforl is:

a. Higher in witttt:r thnn lhat in summur b. Low4...T in winter Lhan tlutl iu s.wmuer \!. Same-m winh.T and st.unntcr d. Nul deJ"'ndcnl on season. Which on" of the folio\\ ing causes lift 011 an fnm1en;ed body in a fluid •tr""m'! a. Buoyant fore"" b. Rosultonl lluid force on lbe body

c.. Dynamic fluid force componenl e.xerted on r.he body parallel to the opproaclt velocity

d. Oyn.:Q'U ic tluid fore<: ~<1mpononl <:xertod on Ute body to Utt "JIJ)I'oacb velocity

If for o flow a ~treom funcrion •11 c:x.ist..; tll\d solisfies the U.p lace eqlll3tlim. Uten whi-ch one of th" fo llowing is the correct st.Btcmen1'!

a. Th" continuity equation is s,,tiJ;fied and the tlow is in·igational

b. The continuity equation i• soli.sficd and rhe flnw i~ rotrdion:a1

c. The llow is iNigaliona l but do"S not sati•fy the cont inuity equation

d, 'l'he Oow is rotation~ I

When • vertical cylindrica I ves.•el conla ining water ;, rota led almut Jb axis. tJocn tb" free s urfAc'C of wnlot· become'S: a. A cycloid of revolulicm b. An dlipsoid of revolution c. A hyp~"fboloid llf oevolulion d. A paraboli.: of rovolutiou

Which on<! of lh~ followil•¥ Sl:JtcmtnlS is comet? The prossuru et.•ntro- is:

a. The ccnlwid of the po cssurc: prisnt

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b. A point on c:he ITne of action of the rcsulrom tbrce

c, At the ceniioid of the submerged area d. Alway~ above the centroid of the area

" I •. A-;cr I~ ~-~.J. L-~--------------+ S

Which one of the (oJJowjng express.:s the isentropic efficiency 17 of the compression process in terms of entl1alpy changes as i!odicated in the figure given above'/ a. 11 : Ml, I t;.H

b. 17 -= Mll Ml

c. q= (MI - Ml, } I MI

d. 'I: (All MJ, )1 Ml,

While nuwing through the l'<)lUI' blades in an axiul flO\\ air CUIIIprl"SSOr, the relative velocity of air; a. Continuously decreases b. Continuously increases c. First increases and ~1en decreases d. First decreases and then increases Consider the tbllowing properties of a fluid: I. ViscoSity 2. Surface tension 3. Capi llarity 4. Vapour pre~sure Which nl' the above pmpenk s can be attributed to the flow t>f jet of oil in (lJ1

unbroken swam? a. I only b. 2 only c. I and 3 d. 2 aut!~

Why is a mini mum of Net Positive Suction I lead required for a hydraulic pump'! a. To prevent cavitations b. To increase discharge c. To increase suction head d_ To increase efficienc)•

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J ul' !J Which one of tl1e following turbines exhibits ~ nearly constant c.fticien~y over a 6()% to 140% or d"si!,,'Tl speed'?

a. Pehon turbine. b. Francis turbine c. Deriaz turbine d. Kaplan turbine When a hydraulic norblnc is operated. it is found that it has n high design efticiency and this cflicicncy r~maln5 tOn>tant ovct a wide ran~;e of regulation from the design conditiooc What is the trpe of tltis turbine? a. Pelton b. Ft-aocis

c. Kaplan d. Propeller 1'hc functinn of whi~h of the following hydraulic. devices is analogous to thnt or the flywheel of a reciprocating engine and an electric storage battery? a. llydraulk ram b. Hydraulic accumulator c. Hy<lraulic intensifier d. Hydraulic jack The Euler's equation of mtllinn is n statement of:

a. En<.'rgy balance b. Conservation of momentum rot an in

viscid lluitl c. Conservation of momennun for an

incompressible now d. Conservation of mome-ntum for a reul

fluid Why is compounding of steam turbines do11e? a To improve eni~i cncy

b. To reduce IlK· Sp<?ed of rotor c. To reduce exit losse; d. 'To incr.,-~se the. turbine output C on~idcr the following, Statements: Which Qf lhe following increase the work ratio in a simple gas turbine plant? l. Ileal exchanger 2. I mer coollng 3. Reheating Select the correct answer ustng the code. given below: a. I and2 b. 2 and 3

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c. I liJld 3 cl. 1, 2 nnd 3

For centrifugol compressot'5 which one of the following ls the relationship between

pre>NUre coofticient ( ¢1, ), slip faclnr ( .P, ) ,

\vorl, input l'a~tot ( 11. ) imd i~~n ti'Oj>ic

cft'icic'tlcy ( lf4

) '!

n. '· = ' · "· "· b. ; ,, ;,

~--, /]

c, ;,- , ~ '1.,

<1. ; : , •/], p " ·

Which ono of the tollowing st~tements 1• no.t true for n superc.ritiO;Jl steam gcnerntnr'!

a. It ha.s a V•1)' small d.rum compa"'d to a .:Dnvcntlunul boiler

b. A super<ailical pn:s.w-e plant has higher efJieienoy than a suh critical pressure pl•nl

c. 'I he feed pre.-.ure required tS very high. uLuosl 1.2 to 1.4 times U1e boiler pressure

d. As it rc:quirc. nbsululcly pur;, fw d water. prepornlion of feed water i• more important fh;m in a sub critical pt..:ssure boilet

For a nMI theomodynamic o>yde. whfch unc of thu follow in~ is cot1'<>ct7

a, [~(l< = O

b. ~dQ <.0 7'

c. rf~~ = 0

d. ~ds= O The equalioo relntina the following mea.<uroble propcrtic::~ ' (i) ilte Mope of soturotlon pn:ssun::d temperature line. ( ii) tbc latent hoal. and (iii) the d1nnge In volume dluing phase trnnsfonnarion: is LJm\Vn as:

a. Maxwell relation b. Joules equation

c. Clapeyron equation

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·' " ' IJ d. None oftlte obovc. Which .,r the following ""' iJttensive­prnper1ies1 1. Kinetic Energy 2. Specific Enthnlp)' 3. Pn::ssure 4. Entropy Select the correcl answer using the C<Jde. given below: a. I and 3 b. 2 and::.

c. 1, 3 and 4 d. 2and4

In a Brayton cycle. what L• the voluo of optimum pr~s•= ratio for maximum net work don~ ~two~n tcmpct'aturcs T1 nnd 1';, where 1', i• the maximum temperature -and T1 is lhe minimum 1empernh1re1l

c. 'r =l:, )*" i r-e!

(T ) ' d. r,. = ..!. T,

A Beii-C'c>leman air reliigcrati<ln cycle '' t wk.<J as u n:v crs.c d : a. Stcrlins cycle b. Otto cycle c Die1el cycle d. Brayton <>yde Which one of U1e following cycles bas lhe highe•l U1.:rtlllll cfficiancy for given tnA.~imum ""d mrnonlllll cycle temperatures'/ a. Brayton cycle b. Otto cycle c. Diesel eyde d Sterling cycle An engine produces 10 kW bre~k power wbile working with a bl'ake U1ermal ~mct"ncy of 30'1•. If tltc calorific value of the fut~l used ;. 40.000 kJ/kg. then whnl is the lite! con.umption'l

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o.. l.S kg/hour b. 3.0 l;glbour c. 0.3. kg/hour cl. 1.0 l;glhour

/1 40 kW engine has n me<:h:tniC<•I eOiciency of S(t'lo. If ~te frictiona l power 1s nssumed lo he "onsl~ml with hlad, wh31 i~ ~'" app•·ox.imMc value oJ' I he mccu#ujc,,l e tlic•ency al 50~"' of lhe ralorl lond? a. 4;~1J

b. 55°o c . 65uu

d. 7S'•u l\'lalcll List! (S.J. Englno Operating Mo<W) with List II {Approxim•le iVF Rallo) and select lhe correcl answer using lhe code given h<low the Lisls: Li.J I A. Cold StnTI B. ldling C. Cruising D. Maximuru .Pow01·

Lisl n I. 11):1 2. IG:J 3. .j._

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n. b.

1 ~: 1

4: 1 20: 1

t\ 4 2

B 3 I

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I)

~. 4 2 3 cl. l 3 5 I l'h<= knoc~':ins tendency In compress ion ISJ!Ilion <-'IISin<ll< incre~l.'c<~ with: 'L lncroasc of c<)O)anl "ater iemp.:mture b. lncrea~e of tempera lUre of inlet air ..:., Decrease of compres.~ion ratio d Increase of compression ratio Wblch of the following cannot be caused by n hoi spal'k plug1 I . Pre-ignition 2. Post-ignition

3. Deton•tion 4. Run-on-ign ition Selecl the con·ect answer us ing Ute code given below:

n. L ontl4-

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~ " ' IJ b. 2only c. 2 and 3

d. 3 only Con.•id¢r 1be li>llow i11g •~>lcmentx: L. Sup~Nh:trging incre~e. ~tc power

outpul ond increases the volumetric cftltitJnc.y·.

2 Supercharging is more $Ull:l.b]e lilr s.r. uoginC$ lban CJ . engines.

3. The lintil of supurehar'!!ing fm uu SJ. c'llgine is •cL by knock while tl~:~l for n ('.L engine i• ••I by thermal load in g.

Which of the s tatements given above are com:ct1

a. 2 and,:; b. l.hnd 3 c. Land 3 d. I and 2 Which one of the following c~nnot be controlled by a three-way C<lWlytic converl4.1r'l

a. BC emission b. CO umission c. NO. emission d. SPM emissiurt The discltarge of hydJ'Ot•rbon~ from Jl"ltOI automobile oshawot i.~ minimum when Ute \'ehicle is: a. Idling

b, Cruising c. ,\ccelerating

d. Occelemting Weight percentage nf wh•ch rme <Jt' tht

fo llowing ;, dc:tennined hy J>roxim>te an• lysis of' coal? ;~ . Fi.~od ~:arbon. \'ulatile m'ilUcf. u\hi:1ture

$nd a.Ut

b. ;\11 solid <tnd !i•scous component;

c. All solid & g:tseous components except volatile marter

d. Fixed c~1rhoo •nd Yolotile malfor Which one of tl1e following fuels can be obtained by ferrnenlalion of vegetable maller? a. Benzone

b. Diesel c. Gasoline

d. Alcohol

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For which of ~1e following. re.1.Sons, do the indirect injeetion dk'Sel engine:; have ldgloer spcd lio nulpul cnmp>rcu to dirc~t Lujc~.tion c.licscl cngln~'l

l. TI1cy h•va loll or ~urface 10 volume mHo.

2. They nm al higher •Jieells. 3. They hAYC higheT air utiliu tion factor. -1. Tiley h•vo lower l'l:l:otive hc•tlos~.

Sel~t the con cc.t answer using Ute coda &<iven bolow: o, I and 2

b. 2only c. 2 tmd 3 d ~ and .t W hich one of lhe following stalem~'llls Is not correct for a '"801\erlltive steam cycle? • · It increases the thermodynamic

~ft'ici_~ucy

b It reduces boiler capAcity for n given output

c._ It reduces lentp'-•roturc stresses in thu boiler duo to ho tter feed

d. The efficiency incren~e~ with incre:osed number nf feed healers

Which one of lhe following ts the correct s~ntcmcnls?

·n,e dcgl'l!c oJ' reJ~otioo nf ao Impulse turbine: I. t. less than Zero 2. 1~ grcowr than zero 3. 1, c~u•lto Z<-'1'1>

4. lnc•·••ses with stcam \•olocity nl U1o inlet

Which """ qf the lo Uo,,ring is Uoe ~~~ ·~""' sootemenl? fo get sUp<'TSOnic veiOCJI)' of $to3m nl noz.zk ex:it with u Iorge pressure dmp acouss it. tbc uuclmllSI:

n. t:<lltverg<> from inlet to e:til b. divc:rgc from inletlo e:<it .:. lirsl convo:rge to ~te ll1root and thc:n

div~:~r:go till o:<il d. J'CllUiitt to!Oil8laul in Cl'tJSs .. s;oolio n

Whicb one of the foUowins is rJo" co'"""' ex'Pf"S''ion for the propuls ion cfliciency of • jet plane tneB iec.ting the mass of fuel)'/

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54.

.. ,,, -[~)- I

b. q, ~ (:/)+ 1

c. ,.,, 2

(f-) d. , , ~ (L)- 1

r.

6ofl3

(Where VJ vd ocity of jet rololive lo p1auu, V, ~ velocity ofth" plane) A nuclear -unit ht:c.umjng critlc.1l mc.an!l-: u. It is getotll'Oling power to r'Jtod capacity b. Jt is cnp•blo ol' gc'nc.rating JlOWco· much

more thion the r~ted capo1city

c. 111ero Is danger ofnucle"r 81)1'103d

d. Chain rt:.lcticm th:ll causes ttn1om:1~ic:

splitting of the li•el puc.lei has l><oen t$tablished

S.'l<'o·lioln (A): For " mixture olf ~oliil. l i.quid and vupour J_)h:t~cs of o1 pure suhslnnce in equilibrium lbe number of indo:pcndcnr intrinsic propertio:s n<:edcd L< <:qiUIIIO OJ!O.

Reason (R): The lhr~-c phil$<:.> tan c<Jc~isl

Only nt nne piu·tjculnr IH'o.J.!fUrc .

a. Both A and R nrc indivlduolly ttuc <1nd R is the correct exphmorion of A

b. Both A and R are individual!} truo bul R is not the correc.t explanation of A

c. A is ln1e hut R 1s 1:11se d, A is fal<e bui R is lrue Assertion (A): Thennodynnm ic work i• pa~1-dependent .:xcepl for '"' ntliabatie p1'0CC!S-

RcnsOn (Rl: is always po•siblo: to Ink~ • •yslcrn !Tom a !!,h'l'.n in itial •bte lo any finn! slate by performing adiabatic work only. 11. Both A and R 3l'e indiVidual!~ lru<> and

R is tho correct c.'<plftnation of A b. Both A and R oro iJl<tividu•UI true but

R is not the correot a:>planotio'n of A c . A is true but R is false

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,1, 1\ is l'ols~ but R is true Ass4.•rtiun (-\ ): An ncli:,h:.tic prnces~ i10

il l\\~I)'S :1 e<lnst~nc entrqpy proCe!jiM ..

l~eaM~n (R): In an ad1abntic process there iR nu helt lransl'er. ~, 'Both ' ' and R 31'e andividUlllly tl'\le ~ntl

R is Ute cort•oot cxfll3nalion of \ b. Both A and R ate indivitluaUy true hut

R is nQtthe correct e.xplonMiun uf A

c. A is true but R is false d. A is false but R is true

Assertion (A): A Vllnc lJ'l'C rotary compres..•;or is a rot dynamic m-ach me. Rca<on (R): A rot dynamic mochine is one in whlch a flu td flow~ freely tbroogh tb" fotating pnrt of th~ n\Jl~bJne.

a. Both A and Rare individually tn1c !Uld R is lh~ con..,ct txpl3nation of A

b. Both A and R arl) indn•iduolly lru~> but R is not the corNet ""PI•nntion of A

c. A is true but R is fal~e cl. A is /'also but R is true Assertion (A): The buoyant forc'C for a floating bod} passes lhroogb the oentro1d of the displa~ed volume.

Reusun {R): 1l'tc ror<:c of buq~uncy is • vertical fol\.-o &: ~Ull l lO lhr: \\<llj!hl of tluid di"J'lnced. a. Ood• A :lnd R lire individunlly lnlo :md

R 1~ lhe C(lm:ct CXIll~nati<)n 11( A b Both A nnd R Me individually true hut

R Ill nut the o::ur"'d olcplnn~tiun of A c. A is tJ·ue but R t• t'al~e il. A is ('ol•c but R i~ lru~ Ass~rtluu (A): G:t.~ oJ•d stre-Jm noztlt8 :ore shaped at inlol in su<>lt • way tltot !be nozzle convel'ge• tlq'lidly over the first portion of hs length. l{ca'<On! ' !'Ius shope i• provided •o thM velocity ot inlet I<> tlte nou.le i• negligibly ~m3U in compnrison with the ~xit vdocit-y. "" Both A and Rare individually true und

R is U1e con'Oc l cxplonotion of A b. Both A and R arc individually true but

R is not t.he corNet explanation of A c. A is true but R is false cl. A is fa lse but R is true Asso.rtion (1\ ): A correctly designed convergent divergent nozzle W()l'king at de.•iguod coudilion'" is olwny~ chok.:d..

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7 ul 13 R~nson (R): In thC!Oc conditTons the mus n.m throug)l lhe non le is minimum. •· Both A 11nd I< "-e ind ivi1htolly true :md

R U; lhe corr«lt cxnlonoti<!t1 nf A b. BOlli A hmt I~ arc individu•ll) tru<> but

R is nut llac· t:hl'l't:C:.I tx.pluno.liuu uf .r-\ <!. J\ i• tt•uc bt~ R ;,; folse

d. A is f•hcc but R i~ true A.ssl'Yt ioll (A); 11trotUe ~ovem1ng is u6ed only are ~m•JJ steum tu.tinf:S.

Ut>:ISOU (R): . \t p•rt loads.. lb10 dlicic'llcy of SITeam turbine rOOUCOII con; idorahly with tl1mllle governing. ac BoUt A and R are mdiv•dua ll)• tl'lle and

R is the COI""'l cxpbrwtion of A b. BoUt A and R or~ fndlviduaU} trw but

R is not thu COITcct uxplnnntion of A c. A is true but R is false

d. .\ is fa !so but R is U'U~

Ass•rt ion (A): 1n mulli·slogc compressors. the polytropic e:fficioocy is alway~ g:l'ellter limn tbe isentropie ~mci~nc y. Ronson (R): [ligitcT the pt·cs•w·o rotions. the gttal~'l' i~ the polytropic e.tlioicnc.y.

"· Both l \ and R nrc individuo ll) true and R i• tile correct expl~n:lli()Tl of A

b. Both A and Rare lndividWlll) true hut R 1s >lilt the correct cxplilllntion uf A

c, A is true hut R ~· t>•lse d. A is l'nlse but R is tru~ A 4-slm.ke die~<d ~ngine, wh<lll running at 2000 111m ~O.S lllJ !njtcti<\Jl dutntiun uf 15 ms "-ltal is the con·c~pooding durotion of the C111llk angle ln degrees? a. ISO b. ()"

e. 36°

d. 1s•

A rt.'Ve·BihJc engine operate& hctweti:n tempemtur!ls 9()(1 K & 'l'~ ( 1', <' 9()(1 K ), & another reversible eng111e between r, & 400 K( T! - 400K) in s~rics. What is tile value of To if work outputs of boU> engine are equal'! a, 6()()K

b. 625K e- 65tlK d. 675K

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65.

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1\<IDt~b LiJt J with l~iot II ~nd Select the corre.:t arum.:r olsing the code given hei0\1 tit~ l.,i~ts:

List J A CTitie~~l point B. Sublimation C". Tripi<; point 1) . Melting

List lJ All tbe three ph•ses--olid. liquid ~nd vapour co-exists Ill oquillbti um

2. PIU>e cbonge fonn solid to li~uid 3. PtOilCities of s3tutale.l liquid and

saturnl.ed vapour 4r\.l idcntlcaJ 4. ll""ling t>roc:css where solid get~

direcUy lrarudn m1ed to g:ISeous phase A ll C D

n, 2 ,j 3 b. 3 4 2

c.. 2 •I 1 3 d. ' ~ 4 2 A pl;utc waU is 2 5 em thi\Jk with an are;~ of I m'. and has • thermal conductivity of' 0.5 W rmk. If a tempo:t't1lure 1Li1Terence of r.o•c i> i.mposed across il what is the bunt llmv'l • . 120\V

b. 140\V

~ 160W

d. 180\V

Whicb of the follo.wing ure: boiler motmtlngs? I. Fusible plug.

2 Blow·off cock 3. Steam tup ~ . Feed check valve

Select the correct answer usins tho et•rl• given below; n. I. 2 and 3 t>. 2. 3 ond 4 c. I, 3 nnd 4 d. I. 2 :tnd 4

Which on~ of the following .is tho corre<:t p>lh of wat<:.r flow through various comi)Ollenb of boiler of a rnod<:ru U>onual power plant'! a. Economlzcr boiler drum wati!T

walls hoiler drum super heater hll'hine

68.

G!i.

70.

71.

8 of tJ b. Economizer - boiler drum - water wall

- super he.11er - turhlnc

c, econmn izer - water "'""• ht)iler drun1 - supe1· hcatcl' - turbine

d. Ecorlomizor - l~ater walls - super bcat<'f - tut·binc

Wlllll docs Ute rcvtrsod ideal ~terling. cycl~ consi~t ol'l a. Two rev~rsible clotbermal pn>ccsses

3nd twt) rev~ihle :~di:obotic proce>-se!!< b. Two reverRible isothermol proccs"""

11nd two revc~iblc isochnric proccss<'S c. two reverslble isob3rio processes and

two IWo.m!ible odiahatic pro=s.,. d. J\vo rt:Versiblc adinbatic procosses and

two t'IJvasible isocboric process

Change in intontJI energy in a rovcrsibl~ proce!is occurring in a closed sydem ftt equal t o tl1e heal transl'erred if the proces;< oocw·a at ~Jousta.ul: a. Prt.:ssuct: b. Volum~

c. T<tnpe~tutt

d. Enth•lpy In a puly tf()pi~ procc•s. the: term

r~)J p,••, - p,•i [ is eqnolt.o: y-1 ) (re - I) f

a. Hoot obsorbcd or rojo.,tcd b. ChMgc: In int0111• l energy

1 c. Ratio of..!..

1, d. Work done during polytrophic

expan51icm A closed system undergoes o process 1-2 for which the values of Q1.z •nd \111•1 are •20 kJ and 50 kJ, respectiv~ly. If ll1c: system is n:tunted Jo stole, L lU\d (.!:.1 is - I() kJ, what 1s thewlue oft he work w,.,'l • • - 20kJ b. - 40ki c, - R() k.l d. - 40kJ C'hnoge in enthalpy .in " dnsed system is e<JMI t<> the ht:al lr.lnsfc:rr<:<L if the reversi~lc process tokes l>lacc: nt conJitant: a. Tempcrnturx 1>. lnt,CflJal energy e. Pr'<;s.Su rc;

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d. Enu'Opy 73. A O.mnt engine operotc:s octween 27°f'

;m,d nJOC'. If the en _gino pr<xluce. 300 k) of work, whal i~ u,., entropy chunge during he~t uddition7 a. 0.5 kJIK b. J .O kJIK c. 1.5 kJJ'K d. 2.0 kJ'K

74. Which one of the following j• tbc stand) flow t'11Urgy equation for a boiler'?

,t~ \'l ~. I~ ~ _;)_: 1~ + _._

2g.J • 2~1

b. Q ~ (h, '') ,.i ,.;

c. h, >- 1- +Q = Il,+- ·-2gJ 1g.!

tl. w = (h, - h, )+{!

75 A g•• is comp•e.•~d in " cylinder by " movublt pi.<t<>n to" volume nne-half of it~ origin• I volume. During U1c prOC<:!$<, 300 "J '"'"' left tho 2">1 and U1o inlcmol cmt:rg) remained s om"--\\'hot i$ the work don~ on Ill¢ g: .. '/ o. ]{)() kNm

b. 150 kNm o.. 200 k.'IIJm d. ~()() kNm

16. Which of the fllllowurg is/are revtrrsiblc prooess (es)? I . Isentropic e.xp•nSion 2. Slow heotlng of water f()flll a hot

so w-ee 3. Constant pres.u1'1l healing of on ideal

gas fonn a constant tomperal'urc source .1. Evapm'lllion of n liqtiid al const:ull

tempera lure

Select lhe correct 3m;wer Wl'iJl£. Ute coda given below:

" · I only b. tnnd 2 c, 2 nm13 d. 1 and~"

77. !'he irrevon<ibility is defined •s tho diJl'trCJlCc ,,r ~'" ma;<imum useful " <lrk :tnd 40.tUU) WOrk. ] ~ " ' "tt>i. lUt'.f'd \V (lfl l.lll~· How ~n thi< IJC ~ll.ematiwly e..xpt'Ci!Sod?

u. I = 7~ ( .l.'! •~ + 6$., _,.. )

1Jofl3

b. / :Tj,(l!S.,.....-M~,-., )

c. I ~T. (JI!.s.,.,. -~ :,.") ..... -.., )

d. hT, (~...s .... - JAS.,,,,"'- ) 78. Air-condltioning l>:t_< to he done for " hnil

whoso RSII SU k\V tUid RLl I 50 k\V, Tbc:ro are oo other •ourc<:!l of heat addition or leakage~. What Is the v;~lue of the RSHF') 3 . 0.25

b. 0.5 c. 0.75

d. 1.00 7Q rn cmler (c) have a low bypn._ t:1Cic)r Of ll

cooling ooiL ~1e fin spacing and II•• number oftube rows ~!10uld be:

a. Wi<lc ~part and 'high. ""'l'ccth ely b. Wide apott and low rc:.~pc:cti\'el)'

c. Close and lliglt rc:src:cth•cly d. Clo<eand low. rcspoetivol~

80. Air ut dry bulb ternptralorc 111' 35"C 011d dew puint tcmp<'l'aturc of 25•c P"''""" through an :1ir \VaRher whose lemper:1h1re is matolaio.,d at 20°\ Wh•t i$ lhc n•tu•'lt "Ofthe pro~-. involvecl?

"· Cooling ond humidificntion b. St:nsible cooling c. Heating and deh\Jmidif•cation

d. Cooling nnd dohumidilic:J~Iion

81. When 11•• w•l bu lb and dry bulb t.:utplll'olw'Cs ore ~qua~ wltic:h of tbc following st:llt~ments islaf'll cc,rrect? l. Air L• fully snhuatod,

2 Dew poin.t tempi!Tature is reochod. 3. Portio I pressure of vnpour cqu.1ls to the

lolnl pressure. 4. Humidity ratio is l(IO''o a. I and 2

b. I only

c. 1,2 nnd 3 d. land ~

H2. l'<>r an air-conditioned St>:!Ce. RTH = 100 kW. RSHF = 0.75. volume Oow 1111e = 10() m31

mitL aud indoor desigu •l=ific humidity ;,; O.oJ kg/kg of dry •ir \VltM i~ UJ<t•pedfio hvmidily of the supply •ir'l

"· II,() I 11 b. 0.0075

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83.

84.

85.

S6.

87.

~. 0.005 d. 0.0025 Mnt~h Li!.t [ with List 1T and ~elect the C.>ITCCI nnswer using the code given belo\\ lh" Li~"l~: List r A. Dogr.:>e oJ' saturah<m

B. Dry bulb ltm~f)er•mr<r

C. Wet bulb l,em1>era1ure [), l)ew rointtemper~lllre u., 1l I Measure of lol•nt enth11lpy of moist air

2 Measure of lotol enlhnlpy ofmoi~lair

3 Measure of tlut copaclty of all' lo absorb moisture

4. Measure of sens ible enthalpy of moist .... :L.

b.

c. d.

.A 2 3 2 3

B l

4 4

c 3 2 3 2

D 4

4 Which ouc of U1e lo llowiugts responsible lor Ute operotion of • tbcrnto81llli" e;r<p.·ms·ion v3lue'l ;1, Pre~l!un: chang~ in evaporn1or

b Temper.~ tore changes in evaporator C, Degree· of superheat in eVnJJOnltOr

d. Oegree of~ub coo ling in evnporatror A R:frigeratiun plan! n.•cs o condouser wiUo heat rejection ratic\ of 1.2. If the capacity ofUoo ptaJ>t i• :ZIO I<'J '•nin, then what t~ tloc value of lhe rop or u,~ fllfiigerotion point? ;1, 3 b s ~. 7

'" 9 Whicb L' th" mool suil:!ble. type of >ir refrl_ger11tion ~ystem tOr ~-upersonic planes With Ma~h Number 3 or above? "· Boot-strap b Simple evaporative

c. Regenerative d. Boot-strap evaporative

In an ElecJrolux refrigerntor. a, Ammoni~ is absorhed in water

b. Ammoni• os a absorbed in hydrogen

88.

89.

91.

92

93.

10 ul 13 c. Hydrogen is evapor~ted ln n mmoni.1 d. Anunoni:~ ev>purated in hydrogen A revcncd Camol cycle worL'ing as • heat pump has n t'UP of 7. Whnt h tho ratio of lninimutn tO maximum nbl40iutc lc 111 p<.'1"U lUI'CS?

•. 7/8 h. 1/6

"· 617 d. 1/7

A rel~er>tor works on reversed Carnol cycle producing • temperature of ·Hl"C. \V ork done per 1'lt is 700 k.l per ten minutes:. \\ hal is the value of its COP"! a 3 b. 4.5

c.. S~tc

d. 7.0 A. refrigentor ~ased on revet~ed ( 'ar nol e:y-:-le works betwoo:n two tuclt lctnpcratures llml tho rulio lietwl:(on tlo~ low and high temperahlf<' ;,. 0.~. If a heat pump is oper•teil between same lemp.,.llllre o-,mg~. lhcu what would be iLs COP'/

a. 2 h. :>

" · -1 d. s 'llie vahoo• ul' eothalp} -.r the begmoiog uf compn:ssion. :ol tho end of compxcs•ion and at the end of condensation nrc 85 kJ1kg. IRS lcJII(g and 210 kJikg, J't!~pottivcl}'· Wltal is tbe value t)f the C'OP of !be vapour compression refrisernlion sy<tem9

• . 0.25

b. 5.4 e. 4 d. 1.35 In • 11.5 rR tu!p>city wotor cooleo. water enteoos •t 30•c and l.;.we~ at 15"C. What t~ Ute 3Cl\UII water flow o11te? a. 50 litre./hour

b. 75 litr~fhou.r

c. I<M) litresfhour

d. 125 lilreslhoUt \VItal is the shape factor of a hemispherical body placed on. • O•l su•face witlo o•esp•ct to ilscll'J

a. Zoro

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95.

'J7.

b , 0.25 c. (),5 d. 1.0 In " vnpour eompr'C..'iM ion rcfrigtrnlinn plnnt. the retrigernnt leuvt:s the "''nprmllor n! 195 kJ,k ~nd the eon!lcn~er al 65 kJtl\g. For I l.:g/s of refriger.tnL wb~t ~ the rcftigerntion effect?

"· 70 1-:\V

b. 100 KW c. 130 K \V

d. 1(,0 K"\V

Cousidcr !ltc following sL1tom<1uts: L ln • corburulor U1e U= ltlc volvc J.

u•ed to control the fuel snpply . 2. The fuel level in Uur Ooat chaJnb.;f'!l Is

to be about 4 to 5 mm below U1e orifice le\'el of m~ in jt..1.

3. An idle jet pruvid"" <-xtra fuel tlurwg •udden accel~rotion.

~ - An idl\> jet provides cxtm fud during snddert ncceleration richer with fuel.

\\ hicb of the s L1tements given obo, .., are ~orre<:t'/

:L 2 :tnd ~·

b. I rnd 3 c 1,2nnd3

d 2.3 bnd 4 Which Qne nflhe li>llowiJ18 j~ the e<>rrect sl;ltcmdflt~?

l'ur a given centrii\Jgol ptm1p, a. 1n e dischorge varie>< directly .._, 1),.,

speoil

h . ·n,c head vnrie8 ill\'''""'' Y ·~ the spc<:d .:., Tit.: power Vllfi~'ll lUI U1e $quare of th"

speed

d. The disch>~'J!" \'at•ic.< 'Ill the Sttuotc ol' the $peed

Which of th<> fo llowing combustion chamber dt$ign feolun:s mlfiC~ (S) krtu.,kiug m Sl. engines~ 1 Sp.'lrk plug loe.1tcd n..ar the inl~t valve. 2. 'l-heatl

3. Wedge shaped combustion "hambef 4. Short flame ll':lvel tlisL1nce

Solect the corre.:t answer using tl1e rode giVt:n bclo\v:

"· I and 3 b. ~only

98.

99.

(()(I

101.

102.

I I ol IJ c. 3 and 4 d. I and 2 A Polron wh~X>I with S~nglo jet rotates at 600 rpm. The velocity of the jet rrom the nozzle is 100 mls. if the ratio uf the ' 'nne velocity to jet vdocil) is 0.-14, w h• t is Ill<> diameter of tl,e Pelton wheel? a, 0. 7 m

"· 1.4 111 c. 2. 1 m d. 2.8 rn

A po\vdr plan[, whlch mcs a gas hubinc followed by Rteam l11rbme for power j!eneration is <.:ailed:

a. l'oppins cycle b. Bouom ing cycle c. Brayton cycle d. rombined cycle In a radial blade centrifugol C<>mpressor. thcveloeit)' of blade up is 400 m/s ond slip .fuotor i$ 0.9. Assuming the absolute \'clocity nt inlet to be "'<ial, what i• the work clone per kg of flow·• JJ. 36 kJ h. 121<.J c. 144 kJ d. 3(~) ld What shmJid be the rn1io of hlodes(>eed of jet ~peed ti>r tho mtfl(imum dl'i~icncy of n Pcli.'lll wheel?

a.

b.

I 4

l

2 ~ ,

c. II

d.

Which of the following types of turbine is/•re suiL1hle t'or Lid~ I power plants'} l. Tubular turbme

2. Kaplan turbine 3. Bulb t11tbine 4. Proncis tl1rhine Select the C<lrrecl answer tl'lin,g the code g_iwn below: a. I only

b. I and 3 c. 2 >nd 4

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103. d. 4on ly

lf u. i• the bl~de ,1nglu ;,t the outlet. then the maximum hydrnutlc eftic.ienc)• of •n ideal impulse turbine is:

•• I ~ CO:IIl

2 1- cos.;,

b. 2

1- sio a

2 l ; sina

tl 2

104. Which one of tl1e dimC~~J~lou.less uumbo:t·s idc'tltifies the comprc:ssibility cl'fect of a fluu:l1 a . Euler number b. Pmudo nwn her c. Mad1 number d. Weber number

lOS. A U-lube op..--n •I both ends and made of H mm clia01eter glass luhe n1ercury up lo a heifhl. of Ill em lu bolla Uae limbs. If 19 em of water is uddcd t<> one of Ute limbs. what t5 the difference m merom-y levels in the two limbs >t equilibrium'/ • n. 4.$1J1m b. 1.0 mm c. 2.S mm d. ~.2 mm

I 06 A 4-rc)W vel()city C(lmpmmdcd $lellm

turbin~ dtovdiOp$ llltal 6400 k W. What la the [>OWer dcvelot)t'd b y the last row? rt. '200 kW b. 400kW

"· 800 k.W d. l(i()O kW

107. Whic.h one of tho ltlllv,. inl! L' the lire-tube boi!Cl'/ n. D.nbcoc.k n!Ul \\il)cn'< h<liler h. Looomotjvc lloilct•

c. Slorllng bollur tl. Benson boiler

108. Intensity of radiation ol • surf11ce in perpendicular f;lircction is equal to: a. r~roduct of emissive of surface and 1/ n

h. Pl'nrluc.t nf C'l:nil'!.sivc ur 'HUI'IilcC !Utd 'IT

c. fJroduct of cmissiV\: power of sur!ace­and II "

110.

11 of ~~

d. Product of em~siv1: power of ! urf3ce ami "

In amass U"lln>fer pro~ess or dilfwion of hot smoktl in cold air in a pow .. planlllt~ lcmp..-~tur~ profile and Uto c<lnccnlnltitm profi le will bocomo identical w hen: a Prandtl No. ~ 1

b. NJL<Selt No. 1

c. Lewis No. ~ I d. Schmilt No. : 1

" TlUclt On< of lbe following numbut·~ represents !he ratio of kinem,1tics visco.•fty to th~ thermo I diO\t~ivit~•'l

a. Grash llil' uumber h. Pmmltl ntamb~r c. J'v(oc,h n ll(n her

d. Nusselt number I I t A"er e;qJn~t-•itlo frl)m .a gos turhinc, the hot

c.<houst gnses arc used to h~l. ~"' compressed •lr frorn a C<Jmpressor wilb lhu help Of ~ CTO!;S lfOW COmpact heal e;;;ehnngcr ofo.g efti:ctivencs~. \Vhnl is th e number Qf trnn•fer units of the heat cxclmngor?

a. 2 b. II c. 8 d. 16

112.. A lbiu flol plate 2m •2m is hanging fi-eely in air. Tile t<.·mpcraturc of the surroundings i$ 25°C. Solar rodiation is fo iling on one side of the plate at U1e me of 300 \VIm'. \VItot should be Uto ~nveelive boat tunsfcr cocfficimt i• \\'lm1"C.'. if lhc lempemture ol fhe plate is to remain C(tnstant al .30"(''1 • . 2) h. 5\1 c. 100 d. 2(10

It~ . Jn order to •~hlwe maxilmun heat dis~ipotion. the lin ~hould be dcsi)!ned in such n wo.v tllot ; u. n should hove maximum l:•tcral

~urf3cc 01 ~~e root ! ide of the lin b. It sholal4 hnvc maximum 1:.1,1'lal

surface ·t(lwards the tlp•ide of the rin c. II •hould have maximum lnlernl

surf11.ce ncar the centre ul' ll1e tin

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d. It ' hoold lAve. minimum L11cral $Urfaco near the t entre uf the fin

tt4, A c()mp<,.lte h<1llnw spht:re with steady int"'11• t h<:llting is mode of 2 Ioyer• of m:oteriols of equal tlticbteu w itb Otdtmol conduetivilies in th~ l'lltio of I :2 for Inner to <)Ulcr layer:;. Rallo nf in> ide to ouL•ide diamell:r is 0.8. What is ratio of lcmp<Ylllnr<: drop "cross the lm•cr 1111d cruter 13-yen;'?

•• 0.4 b. 1,1/ c. 2 in 0.~

d. 2.5 115, L'p to tho criti""l radius of insulation:

II ~.

117.

a.. Added in.sulolion increases~ heat loss b. Added insulation dccrcoscs heat loss c . Convectio n beo.~i loss is los.s tb.n.n

conduction heal loss d. He.1t flux decreases.

l\lotclt List I (GoYeming Equations of Heot l'nnsfer) with Li>t U (Spedf"' C'oses of Fl""t Trnnsfer) ond sd~cl t11o COI'tect answa using t.htJ code ~fvcn below: LiS~ I

A d'T ~ 2itr : O clr' t•dr

il'T l ilT B. iJ.<' : a (II

C. J1T , ldT - O

lir' r Jr

d 'O • D. ,fx' - m·IJ= H

Li~t IT l . Pin i]n l · D cnsc

l . l ·D oondu~tion in cylinder 3. 1-D condition uu pl1crc

4-. 1' lo1te !iln h (Symbols hove their usuol mc.>ning)

A B C 0 n. 2 <I 3 1

b. 3 I 2 4 c. 2 l 3 ~.

,l 3 4 2 l

6.0 kJ of condition ltoal U11nlifcr hJ.'< to lllko place ju 10 minul<;s from one <'!ld to other end of o metallic cylinder of l ll em= uross-

13ofl3 sectional aren. length I metre nnd lherm~l condu.:.tivlty as 100 WlmK. What t S the lcrnp<.Tllturc diiJ'cn:nc<: hetwccn the two ~uds of the cylindric3l bnr? a. SO"C b. 1oo•c c. 120"C tl 160"C

liS. Ht:at is conduced through • 10 cnt lhk k wall ot ill~ rote of 30 W/m2 wh011 the­ternp=ture dilfen.'nce across the wall is IOC. \l~>nl is lhc thermal ~tlnduetiV>IY 11f the woJJ1

119.

· ~·

a. 0.03 \VImK b. o.J \VimK

e. 3.0 W/ntK d. 30.0 \V/ !Uk Motch List J wltlt List ll ond sel<lct tl•e coi1"Qcct nnswcr using Llu.: code g.ivcn bclo\V the Li•ts: List I A. Radiation heot u·ansfer B. C'onducuon heal trnnsfer

(", Forced '"'"' 'e<:t ion

D. Tranlrient heatllo1< List n I. Fourier number 2. Wien diS)llacemcnt lnw 3. Fourier b w 4.

•• b. c.

Stunton number

A 13 2 -1 3 2 3 4

c -1

2 -1

2

D

3 Hcislct· chart" .u-c u.>Scd tn dt.lcnuinc trans ient heot llow rote and tem1>ernture distribution when:

a. Solids posses infinitely large tl1enn al c.mducl:ivity

b. Internal conduction resist.mce ls sm~ll and eonvecuw r~sistllnc.: is lnrgo

c. lutc,'t11al coltduclion '"sistaucc is large :1nd the oonvcctivo 1--es islam:c is !lnLlll

d. Both conduction and con\·ontion resi<tomcc are almost of etr••l sig.JtiJicance