che objective type questions compilation-dean medina 8-28-10

8/9/2019 ChE Objective Type Questions Compilation-Dean Medina 8-28-10

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CHEMICAL ENGINEERINGOBJECTIVE TYPE QUESTIONS:

A COMPILATIONDR. LEONARDO C. MEDINA, JR.

DEAN, COLLEGE OF ENGINEERINGLYCEUM OF THE PHILIPPINES

UNIVERSITY

CHEMICAL REACTION ENGINEERING AND

REACTOR DESIGN

1. Rate of chemical reaction is independent of the concentration of reactants for(a) ze! !"e ea#$%!&(b) third order reaction(c) consecutive reaction(d) none of these

2. Which of the following is not a unit of reaction rate?(a) moles formed/(surface of catalyst) (time)(b) moles formed/(volume of reactor) (time)(c) mole formed/(volume of catalyst) (time)(") &!&e !' $ee

. !f "n# is the order of reaction then unit of rate constant is(a) * ($%+e) (#!e&$a$%!&)&*

(b) (time)$1(concentration)n$1

(c) (time)n$1(concentration) (d) none of these%. Which of the following is a controlling factor in very fast heterogeneousreaction? (a) ea$ a&" +a $a&'e e''e#$ (b) pressure (c) temperature (d) composition of reactant&. 'ariables affecting the rate of homogeneous reactions are (a) pressure and temperature only (b) temperature and composition only

(c) pressure and composition only (d) -ee, $e+-ea$e a&" #!+-!%$%!&


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. Rate determining step in a reaction consisting of a number of step in series is the (a) fastest step (b) /!0e" $e- (c) intermediate step (d) data insufficient can*t be predict

+. ,hemical -inetics can predict the (a) a$e !' ea#$%!& (b) feasibility of reaction (c) both (a) and (b) (d) none of these. 'elocity of a chemical reaction

(a) decreases with increase in temperature(b) increases with increase of pressure of reactant for all reactions(c) decreases with increase of reactant concentration(") &!&e !' $ee

. 0um of the powers of the concentration terms in the rate euation is called the

(a) order of the reaction(b) !1ea// !"e !' $e ea#$%!&(c) molecularity of the reaction

(d) none of these1.3olecularity of a reaction

(a) is always eual to the overall order of reaction (b) may not be eual to the order of reactionc (c) can4t have a fractional value

(") 2!$ (2) a&" (#)11.!nversion of cane sugar is an e5ample of

(a) unimolecular reaction with first order(b) bimolecular reaction with second order(c) 2%+!/e#/a ea#$%!& 0%$ '%$ !"e(d) unimolecular reaction with second order

12.,oncentration of the limiting reactant (with initial concentration of a moles/liter)after time t is (a$5).6hen t for a first order reaction is given by

(a) 3$ 4 /& a a5

(b) -t 7 5a(a$5)

(c) -t 7 ln a$5 a

(d) -.t 7 a (a$5) 5

1.8alf life period of a chemical reaction is(a) $e $%+e e6%e" $! e"#e $e #!e&$a$%!& !' $e ea#$%&7 2$ae$! a/' %$ %&%$%a/ 1a/e(b) half of the space time of a reaction

(c) half of the residence time of a reaction (d) none of these


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1%.9ill up the blan-s:8alf$life period for a first order reaction is....................... the initial concentrationof the reactant(a) directly proportional to

(b) inversely proportional to

(#) %&"e-e&"e&$ !'(d) none of these1&. 9ill up the blan-s from among the alternatives given below: !n a first order reactionthe time reuired to reduce the concentration of reactant from 1 mole/liter to .&mole/liter will be ............. that reuired to reduce it from 1 moles/liter to & moles/liter inthe same volume

(a) more than(b) less than(c) a+e a(d) data insufficient can*t be predicted

1. 0pecific rate constant for a second order reaction

(a) is independent of temperature(b) varies with temperature(c) depends on the nature of the reactants(") 2!$ (2) a&" (#)

1+. 6he reaction in which rate euation corresponds to a stoichiometric euation is called(a) e/e+e&$a8 ea#$%!&(b) non$elementary reaction

(c) parallel reaction (d) auto-inetic reaction1. ;uilibrium of a chemical reaction as viewed by -inetics is a

(a) "8&a+%# $ea"8 $a$e(b) static steady state

c (c) dynamic unsteady state(d) none of these

1. 9or a


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21. 6he energy of activation of a chemical reaction(a) is same as heat of reaction at constant pressure(2) % $e +%&%++ e&e78 0%# $e +!/e#/e +$ a1e 2e'!e $e ea#$%!a& $a3e -/a#e(c) varies as fifth power of the temperature

(d) both (b) and (c)22. Rate constant *-* and the absolute temperature 6 are related by collision theory (forbimolecular) as

(a) - 6 1.&

(b) - e @;/R6

(#) 3 T(d) - 6

2. 6ransition state theory relates the above uantities as(a) - e @;/R6

(b) - 6e@;/R6

(c) -

6(d) - 6 1.&

2%.Reactions with high activation energy are (a) 1e8 $e+-ea$e e&%$%1e (b) temperature insensitive

(c) always irreversible (d) always reversible

2&. !n autocalytic reactions (a) one of the reactants acts as a catalyst (2) !&e !' $e -!"#$ a#$ a a #a$a/8$ (c) catalyst has very high selectivity

(d) no catalyst is used2. With increase in temperature= the euilibrium conversion of a reversible e5othermicreaction

(a) "e#eae(d) increases(c) remain unaffected(d) decreases linearly with temperature

2+. With decrease in temperature= the euilibrium conversion of a reversible endothermicreaction

(a) "e#eae(b) increases(c) remains unaffected(d) increases linearly with temperature

2. 6he euilibrium constant of a chemical reaction(a) increases in the presence of catalyst(b) decreases in the presence of catalyst(#) e+a%& &a''e#$e" %& $e -eee !' a #a$a/8$(d) can either increase or decrease depends on the type of catalyst


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2. ,onversion increases with increase in temperature of(a) >utocatalytic reaction(b) !rreversible reaction(#) Re1e%2/e e&"!$e+%# ea#$%!&

(d) Reversible e5othermic reaction. 6he heat of reaction (a) depends on the pressure only

(b) depends on the mechanism of reaction only(c) depends on both pressure and mechanism of reaction

(") % %&"e-e&"e&$ !' $e +e#a&%+ !' ea#$%!&1. !ntegral method for analy tric-le bed reactor is one which(a) has altogether three streams either entering or leaving(b) processes three reactants at different flow rates(c) processes three reactant with same flow rate(d) e+-/!8 a// $e $ee -ae (%.e. !/%" /%6%" a&" 7a)

&.>ccording to >rrhenius euation of temperature dependency of rate constant for anelementary reaction

(a) - 6(2) 3 eE9RT

(c) - 6e$;/R6

(d) none of these. With increases in temperature= the rate constant obeying >rrhenius euation

(a) %eae(b) decreases(c) decreases e5ponentially with temperature(d) can either increase or decrease= depends on the freuency factor


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+. > batch reactor is characteri plug$flow reactor is characteri


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(") 2!$ (a) a&" (#)%. > space$time of hours for a flow reactor means that

(a) $e $%+e e6%e" $! -!#e !&e ea#$! 1!/+e !' 'ee" (+eae" a$-e#%'%e" #!&"%$%!&) % !

(b) three reactor volumes of feed can be processed every hour

(c) it ta-es three hours to dump the entire volume of the reaction with feed(d) conversion is cent per cent after three hour%+. 0pace time euals the mean residence time

(a) 0e& $e "e&%$8 !' $e ea#$%!& +%5$e % #!&$a&$(b) for large diameter tubular reactor(c) for narrow diameter tubular reactor(d) for ,06R

%. 9luidi


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&%. Dil hydrogenated using nic-el catalyst in a(a) batch reactor(2) /8 ea#$!(c) fluidi second order reaction of the form >EF , is called a pseudo$first order reactionwhen

(a) ,>D7 ,FD(b) ,>DG ,FD(c) ,>D ,FD(") CBO= CAO

&. > first order irreversible reaction > F is carried separately in a constant volume aswell as a in a variable volume reactor for a particular period. !t signifies that

(a) both conversion as well as concentration are same in the two reactors(2) #!&1e%!& %& 2!$ 0%// 2e $e a+e 2$ #!e&$a$%!& 0%// 2e "%''ee&$ %&

$e $0! ea#$!(c) both the conversion as well as concentrations will be different in the tworeactors

(d) none of these&+.> space velocity of & hour means that

(a) '%1e ea#$! 1!/+e !' 'ee" (a$ -e#%'%e" #!&"%$%!&) ae 2e%&7 'e" %&$! $eea#$! -e !

(b) after five hours= reactor is being filled with the feed(c) cent percent conversion can be achieved in at least & hoursc (d) a fi5ed conversion of a given batch of feed ta-es & hours

&. Which of the following fi5es the volume of a batch reactor for a particular conversion

and production rate?c (a) operating conditions (e.g. pressure and temperature)d (b) rate constante (c) "e&%$8 !' +%5$ef (d) none of these

&. !n a ,06R(a) reaction rate varies with time(b) concentration varies with time(c) both (a) and (b) occur(") &e%$e (a) &! (2) !##

. 6he use of space$time is preferred over the mean residence time in the design of

(a) batch reactor(2) %"ea/ $2/a'/!0 ea#$!(c) slurry reactor(d) ,06R


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1. 9or all positive reaction orders for a particular duty (a) +%5e" ea#$! % a/0a8 /a7e $a& $e -/7'/!0 ea#$! (b) the ratio of the volume of the mi5ed reactor to that of the plug$flow

reactor decreases with order

(c) reactor si Fis carried out separately in ,06R and B.9. reactor of eual volumes. 6he conversion willbe

(a) %7e %& P.F. ea#$!(b) higher in ,06R(c) same in both the reactors(d) data insufficient can4t be predicted

. 9or an autocatalytic reactor= the suitable reactor set up is(a) B.9. reactors in series

(b) ,06R in series(#) CSTR '!//!0e" 28 P.F. ea#$!(d) B.9. reactor followed by ,06R

%. 9or multiple reactions= the reaction within the vessel affects the(a) 0i first order reaction reuires two eual si


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. Which of the following is the optimum operating condition for an e5othermicreversible reaction$ta-ing place in a plug$flow reactor

(a)Te+-ea$e !/" 2e %7 %& $e 2e7%&&%&7 a&" "e#eae"$!0a" $e e&" !' $e ea#$%!&

(b) 'ery low temperature should be used throughout the reaction

(c) 'ery high temperature should be used throughout the reaction (d) Hone of these+. With increase in the space$time of an irreversible isothermal reaction being carriedout in a B.9. reactor= the conversion will

(a) Ieae (b) Aecrease (c) Remain same (d) Aata sufficient can4t be predicted

+1. 6he optimum performance for reactors operating in parallel is obtained when the feedstream is distributed in such a way that the

(a) S-a#e $%+e '! ea# -aa//e/ /%&e % a+e

(b) 0pace time for parallel lines is different (c) Iarger reactors have more space time compared to smaller ones (d) Hone of these

+2. Fac- mi5ing is most predominant ing (a) > well stirred reactorh (b) Blug$flow reactor% (#) A %&7/e CSTRC (d) ,06R connected in series+. 6he ratio of moles of a reactant converted into the desired product to that convertedinto unwanted product is calledc (a) Dperational yieldd (b) Relative yielde (#) Se/e#$%1%$8f (d) Hone of these+%. 6he performance of a cascade of ,06R4s can be improved by adding

(a) a B.9. reactor in series(b) a B.9. reactor in parallel(#) M!e CSTR> %& e%e(d) 3ore ,06R4s in parallel

+&. >n auto thermal reactor is(a) 3ost suitable for a second order reaction(b) 3ost suitable for a reversible reaction(#) C!+-/e$e/8 e/' --!$%&7 %& %$ $e+a/ e&e78 e6%e+e&$(d) !sothermal in nature

+. 9or series reaction=the(a) Relative yield is always greater for plug$flow reactor tha) for the single

,06R of the same volume(b) 0tatement in a is wrong(c) Relative yield decreases with increasing conversion(") B!$ (a) a&" (#) !/" 7!!"


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++. When a high liuid hold up is reuired in a reactor for a gas$liuid reaction=use

(a) Bac-ed column(b) 0pray column(c) 6ray column

(") B22/e #!/+&+. 9or reactions in parallel viJB (desired product) and >JK (unwanted product)=if the order of the desired reaction is higher than that of the undesired reaction= a

(a) Fatch rector is preferred over a single ,06R for high yield(b) 6ubular rector is preferred over a single ,06R for high yield(#) B!$ (a) a&" (2)(d) > single ,06R is the most suitable

+. !n uestion += high yield would be favored ( for gas phase reactions)(a) A$ %7 -ee(b) >t low pressure(c) Fy the presence of the inner gases in the reactant stream

(d) Foth (b) and (c). When all the limiting reactant is consumed in the reaction= the operation yield(a) !s greater than relative yield(b) !s smaller than relative yield(#) E6a/ $e e/a$%1e 8%e/"(d) ,an be greater or smaller than relative yield= depends on the type of

reaction1. Aesign of heterogeneous catalytic reactor involves consideration of

(a) Dnly chemical steps(b) Dnly physical steps(#) B!$ (a) a&" (2)(d) Heither (a) and (b)

2. Bic- out the wrong statement(a) > catalyst does not alter the final position of euilibrium in a reversible

reaction.(2) A #a$a/8$ %&%$%a$e a ea#$%!&(c) > catalyst is specific in action(d) > catalyst remain unchanged in chemical composition at the end of the

reaction. ,atalyst is a substance which

(a) !ncreases the speed of chemical reaction(b) Aecreases the speed of chemical reaction(#) Ca& e%$e %eae ! "e#eae $e -ee" !' #e+%#a/ ea#$%!&(d) >lters the value of euilibrium constant in a reversible reaction

%. ,atalyst carriers(a) 8ave very high selectivity(b) !ncrease the activity of a catalyst(#) P!1%"e /a7e 'a#e aea 0%$ +a// a+!&$ !' a#$%1e +a$e%a/(d) !nhibit catalyst poisoning


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&. > catalyst promoter(a) I+-!1e $e a#$%1%$8 !' a #a$a/8$(b) >cts as a catalyst support(c) !tself has very high activity(d) >ll (a) (b) and (c)

. > catalyst inhibitor(a) Iessens its selectivity(b) 3ay be useful for suppressing undesirable side reaction(c) !s added in small uantity during the catalyst manufacture itself(") A// (a) (2) a&" (#)

+. ,arbon catalyst accumulated on the catalyst used in the gas oil crac-ing lies in thecategory of :

(a) De-!%$e" -!%!&(b) ,hemisorbed poison(c) 0electivity poison(d) 0tability poison

. 0lurry reactors are characterised by(a) La#3 !' %&$a-a$%#/e "%''%!& e%$ae(b) Bresence of two mobile phase(c) Foth (a) and (b)(d) Heither (a) nor (b)

. > reaction . >J F is conducted in a constant pressure vessel. 0tarting with pure >=the volume of the reaction mi5ture increase times in minutes. 6he final conversion is

(a) .(b) .&(#) *(d) Aata insufficient= can4t be predicted

. 6he most suitable reactor for carrying out an auto$thermal reaction is(a) Fatch reactor(b) ,06R(#) Se+%2a$# ea#$!(d) Blug$flow reactor

1 Which of the following factors control the design of a fluid solid reactor?(a) 6he reaction -inetics for single particle(b) 6he si


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. 9or high conversion in highly e5othermic solid cataly


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CHEMICAL ENGINEERING THERMODYNAMICS

1. Which of the following is an e5tensive property of a system?a. ea$ #a-a#%$8 b. molal heat capactiyc. pressure d. concentration

2. Which of the following is a thermodynamic property of a system?a. concentration b. massc. temperature ". e&$!-8

. 9irst law of thermodynamics is mathematically stated asa. "Q 4 "U ? "@ b. dK 7 dM @ dWc. dM 7 dK E dW d. dW 7 dK @ dM

%. 9irst law of thermodynamics deals witha. "%e#$%!& !' e&e78 $a&'e b. reversible process only

c. irreversible processes only d. none of these

&. >n irreversible processa. is the analog of linear frictionless motion in machinesb. is an ideali


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11. 9or a constant pressure reversible process= the enthalpy ( P8) change of the system isa. , vd6 b. ,p d6#. C- "T d. Q,v d6

12. !nternal energy of an ideal gas

a. increases with increase in pressureb. decreases with increase in temperaturec. is independent of temperature". &!&e !' $ee

1. ;uation which relates pressure= volume= and temperature of a gas is calleda. E6a$%!& !' $a$e b. ibbs Auhem euationc. ideal gas euation d. none of these

1%. !sobaric process means a constanta. temperature process b. -ee -!#e

c. volume process d. entropy process1&. !sentropic process means a constant

a. enthalpy process b. pressure process#. 1!/+e -!#e d. none of these

1. 6hrottling process is a constanta. e&$a/-8 -!#e b. entropy processc. pressure process d. none of these

1+. 6he point at which all three phases co$e5ist is -nown asa. free


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21. 9or an isothermal reversible compression of an ideal gasa. only PM7 b. only P8 7 #. U 4 H 4 d. dK @ dM

22. >s the time is passing= entropy of the universe

a. % %ea%&7 b. is decreasingc. remains constant d. data insufficient= can4t be predicted

2. Foyle4s law for gases states thata. B 1/' when temperature is constantb. P*9V 0e& $e+-ea$e a&" +a !' $e 7a e+a%& #!&$a&$c. B ' at a constant temperature and mass of the gasd. B/' 7 constant= for any gas

2%. 6he euation= B' 7 nR6 is best obeyed by gases ata. /!0 -ee a&" %7 $e+-ea$e

b. high pressure and low temperaturec. low pressure and low temperatured. none of these

2&. ,ompressibility factor of a gas isa. &!$ a '$%!& !' -ee b. not a function of its naturec. not a function of its temperature d. unity= if it follows B' 7 nR6

2. ,ritical compressibility factor for all substancesa. ae +!e /e #!&$a&$(1a8 '!+ . $! .)b. vary as suare of the absolute temperature

c. vary as suare of the absolute pressured. none of these

2+. Reduced pressure of a gas is the ratio of itsa. -ee $! #%$%#a/ -ee b. critical pressure to pressurec. pressure to pseudocritical pressure d. pseudocritical pressure to pressure

2. ,ompressibility factor$reduced pressure plot on reduced coordinates facilitiesa. e !&/8 !&e 7a- '! a// 7aeb. covering of wider rangec. easier plotting

d. more accurate plotting

2. Humber of components (,) phase (B) and degrees of freedom (9) are related by ibbsphase rule asa. P ? F ; C 4 b. , 7B @ 9 E2c. 9 7 , @B @ 2 d. B 7 9 @ , @2


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. Aegrees of freedom at triple point will bea. b. 1c. 2 d.

1. ,p @ ,v 7 R is valid for

a. %"ea/ 7ae b. all gasesc. gases at very high pressure d. gases at a very low temperature

2. >n isolated system can e5changea. matter with its surroundingsb. energy with its surroundings#. &e%$e +a$$e &! e&e78 0%$ %$ !&"%&7d. both matter and energy with its surroundings.e.

. 8eat of formation of an element in its standard state isa. b. O

c. G d. a function of pressure%. 8eat of reaction is

a. dependent on pressure onlyb. dependent on temperature only#. "e-e&"e&$ !& 2!$ -ee a&" $e+-ea$ed. independent of temperature changes

&. 0econd law of thermodynamics is concerned witha. amount of energy transferred2. "%e#$%!& !' e&e78 $a&'ec. irreversible process onlyd. non$cyclic process only

. 6he absolute entropy for all crystalline substances at absolute


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. 9ill up the blan- from among the following:Hear their critical temperature all gases= occupy volumesUUU that of the ideal gasa. /e $a& b. same asc. more than d. half

%. ,harles law for gases states thata. V9T 4 #!&$a&$ b. ' 1/6c. ' 1/B d. B'/6 7 constant

%1. >bsolute


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%. ,v is given bya. ( U9 T)1 b. ( TM/T')6c. ( TM/TB)v d. (T'/ T6)B

&. 6hird law of thermodynamics is concerned with

a. $e 1a/e !' a2!/$e e&$!-8b. energy transferc. direction of energy transferd. none of these

&1. Which of the following euation is obtained on combining 1s6 and 2nd law ofthermodynamics= for a system of constant mass?a. "U 4 T"S ; P"V b. dK 7 ,v d6 E Bd'c. dK 7 ,p d6 E 'dp d. 6d0 7 dM @ Bd'

&2. 6he euation 6d0 7 dM @ Bd' applies toa. single phase fluid of varying compositionb. single phase fluid of constant compositionc. open as well as closed systems". 2!$ 2 a&" #

&. 9or an e5othermic reactiona. only enthalpy change (P8)is negativeb. only internal energy change (PM) is negative#. 2!$ H a&" U ae &e7a$%1ed. enthalpy change is /a0 b. Lirchhoff4s lawc. Iavoisier and Iaplace law d. none of these

&&. ,hange of heat content when one mole of the compound is burnt in o5ygen atconstant pressure is calleda. calorific value b. heat of reaction#. ea$ !' #!+2$%!& d. heat of formation

&. 3elting of wa5 is accompanied witha. %eae %& e&$!-8 b. decrease in entropyc. constant entropy d. none of these

&+. 8elmholt< free energy is defined asa. > 7 8 @ 60 2. A 4 U ; TSc. > 7 8 E 60 d. none of these


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&. ibbs free energy () is defined asa. 7 M@ 60 2. G 4 H TSc. 7 8 E 60 d. 7 ME 60

&. ibbs$8elmholt< euation is

a. G 4 H ? T ( G)9 TVBb. P 7 P8 @ 6P6c. d(M @60)6 =' Od. dB/d6 7 P8'>B/ 6P''>B

. 9or a reversible process involving only pressure volume wor-a. (d)6= pO b. (d)6= pG#. ("G)T, -4 d. (d>)6= v G

1. 9or an irreversible process involving only pressure volume wor-a. ("G)T, - b. (d)6= pG

c. (d)6= p7 d. (d>)6= v G 2. Bic- out the correct euation relating and >

a. G 4 A ? PV b. 7 M E >c. 7 > @ 60 d. 7 > E 60

. > chemical reaction will occur spontaneously at constant pressure and temperature= iffree energy isa. decreases#. 2!$ G a&" A "e#eae d. both and > increases

. Bic- out the ,laussius$,layperon euation from the following:a. dB/d6 7 P 8/6 P' 2. /& P 4 H9 RT ? #!&$a&$c. P 7 P8 E 6 T ( P)/T6VB d. none of these

+. 9ree energy charges for two reaction mechanism X and Y are respectively @ 1& and &units. !t implies that X isa. slower than Y 2. 'a$e $a& Yc. three times slower than Y d. three times faster than Y


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. ,hemical potential isa. an e5tensive propertyb. an intensive propertyc. a force which derives the chemical system to euilibrium". 2!$ 2 a&" #

. ,hemical potential of its component of a system is given bya. %4 ( G9&%)T,P,&% b. i7 ( >/ni)6=B=nic. i7 ( /ni)6=B d. i7 ( >/ni)6=B

+. 9ill up the blan-s from among the following alternatives6he chemical potential for a pure substance U.. its partial molal free energya. more than b. less than#. e6a/ $! d. not related to

+1. Bartial molal uantities are important in the study of

a. ideal gases b. ideal solutions#. &!&%"ea/ +%5$e d. a pure component

+2. 9ugacity and pressure are numerically eual when the gas isa. in standard state b. at high temperaturec. at low temperature ". %& %"ea/ $a$e

+. 6he relation connecting the fugacities of various components in a solution with oneanother and to composition at constant temperature and pressure is calleda. G%22De+ e6a$%!& b. 'an Iaar euationc. ibbs$8elmholt< euation d. 3argules euation

+%. 6he necessary condition for phase euilibrium in a multiphase system of Hcomponents is thea. #e+%#a/ -!$e&$%a/ !' a// #!+-!&e&$ !/" 2e e6a/ %& a// -aeb. chemical potentials of all components should be same in a particular phasec. sum of the chemical potentials of any given component in all the phases should be

the samed. none of these

+&. Which of the following is not affected by temperature changesa. fugacity b. activity co$efficient

c. free energy ". &!&e !' $ee+. 6he activity of an ideal gas is numerically

a. more than it pressure b. less than its pressure#. e6a/ $! %$ -ee d. data insufficient can4t be predicted


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++. 3a5imum wor- that could be secured by e5panding the gas over a given pressurerange is thea. %!$e+a/ 0!3 b. adiabatic wor-c. isentropic wor- d. none of these

+. 6he point at which both liuid and gas phases are identical is calleda. #%$%#a/ -!%&$ b. triple pointc. free


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+. !deal refrigeration cycle isa. same as ,arnot2. a+e a e1ee Ca&!$ #8#/ec. dependent on refrigerant properties

b. the least efficient of all refrigeration processes. 9undamental principle of refrigeration is based on

a. n ideal refrigerant shoulda. not have a subatmosphere vapor pressure at the temperature in the refrigerator

coilsb. not have unduly high vapor pressure at the condenser temp.#. 2!$ a a&" 2d. none of these

%. 8eat pumpa. accomplishes only space heating in winterb. accomplishes only space cooling in summer#. a##!+-/%e 2!$ a a&" 2d. wor- on ,arnot cycle


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&. Which of the following is not a common refrigeranta. freon 12 2. e$8/e&ec. ammonia d. carbon dio5ide

. Aomestic refrigerator usually wor-s on

a. ,arnot refrigeration cycleb. > refrigeration cycle#. A2!-$%!& e'%7ea$%!& #8#/ed. 'apor eCection refrigeration

+. Refrigerants commonly used for domestic refrigerations area. ethyl chloride 2. 'e!& *c. propane d. ,D2

. >ir refrigeration cycle

a. is most efficient of all refrigerationb. has very low efficiencyc. reuires relatively uantities of air to achieve a significant amount of refrigeration". 2!$ 2 a&" #

. ,oefficient to performance for a reversed ,arnot cycle wor-ing between temperatures61and 62(61G 62) isa. T9(T* T) b. 61/(61@ 62)c. (62@ 61) / 61 d. (61@ 62) /62

1. Ary ice isa. moisture free ice b. solid helium#. !/%" #a2!& "%!5%"e d. none of these

CHEMICAL ENGINEERING CALCULATIONS

1. !n flue gas analysis by Drsat4s apparatus= carbon mono5ide is absorbed by(a) #-! #/!%"e (b) potassium hydro5ide(c) al-aline pyrogallol solution (d) none of these

2. ,alorific value as determined by bomb calorimeter is(a) %7e #a/!%'%# 1a/e a$ #!&$a&$ 1!/+e

(b) gross calorific value at constant pressure(c) lower calorific value at constant pressure(d) net calorific value at constant volume

. !ncomplete combustion of a fuel is characteri


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%. 9or ma5imum discharge through a chimney= its height should be(a) 2 meters(b) infinitely long(c) more than 1&.+ meters(") e6a/ $! $e e%7$ !' $e !$ 7a #!/+& -!"#%&7 "a7$

&. D5ygen percentage (by weight) in atmospheric air is(a) 1 (b) 21(#) (d) 2

. 0tac- (chimney) height in a big thermal power plant is dictated by(a) pollution control aspect(2) "a7$ $! 2e #ea$e"(c) limitation of constructional facilities(d) none of these

+. > particular coal is said to be free burning when it(a) burns completely (b) gives smo-eless burning(#) !0 /%$$/e ! &! '%&7 a#$%!& (d) none of these

. >s time passes= the calorific value of stored coal(a) "e#eae(b) increases(c) remains unaltered(d) may increase or decrease (depends on the method of storage)

. ;mission of dense white smo-e out of chimney of a thermal power plant is anindication of the use of(a) less air for combustion (b) correct amount of air for combustion(#) $!! +# a% '! #!+2$%!&(d) pulveri


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1&. 9ischer$6ropsch method aims at(a) gasification of coal(2) 8&$e% !' 7a!/%&e ('!+ 0a$e 7a)(c) hydrogenation of coal to produce gasoline(d) none of these

1. ,ommercial production of petrol from coal (as practiced in a factory at 0asol in 0outh>frica) is done by(a) 8"!7e&a$%!& !' #!a/ (b) gasification of coal(c) carboni


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2. >diabatic flame temperature of a fuel is dependant on the initial temperature of(a) the fuel (b) the air (#) 2!$ 'e/ a&" $e a% (d) neither fuel nor the air

2%. Breheating of(a) the gaseous fuel before combustion decreases the flame temperature

(b) ,ombustion air decreases the flame temperature(#) e%$e $e 'e/ ! $e a% ! 2!$ %eae $e '/a+e $e+-ea$e(d) either the fuel or the air does not affect the flame temperature

2&. 6he fuel ratio of a coal is(a) the ratio of its percentage of fi5ed carbon to that of volatile matter(b) helpful in estimation of its ran-(c) 2!$ (a) a&" (2)(d) neither (a) nor (b)

2. > fuel containing carbon and carbon mono5ide (but containing the hydrogen or itscompounds) is burnt in pure o5ygen at constant pressure. !ts gross calorific value ascompared to the net calorific value will be

(a) more (b) less(#) a+e (d) data insufficient can4t be predicted2+. Removal of hydrogen from co-e oven gas

(a) %eae %$ #a/!%'%# 1a/e (b) decreases its calorific value(c) does not alter its calorific value (d) is not possible on commercial scale

2. With increase in calorific value of fuels= their adiabatic flame temperatures(a) increase(b) decrease(c) remain unchanged(") +a8 %eae ! "e#eae "e-e&" !& $e 6a&$%$8 !' -!"#$ !' #!+2$%!&

2. rindability inde5 of a coal is 1. !t implies that the(a) coal can be pulveri


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. 0team is intermittently admitted in to the fuel bed during the production of producergas to(a) convert ,D to ,D2(b) increase in combustion rate(c) increase the gas production rate

(") +%&%+%ze $e #ae !' #/%&3e '!+a$%!&%.Which of the following is called "blue gas#?

(a) co-e oven gas(2) 0a$e 7a

(c) natural gas

(d) producer gas (produced using Lopper 6ot


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%1. Which of the following constituents of fuel does not contribute to its calorific valueon combustion

(a) hydrogen (b) sulfur

(c) carbon (") &!&e !' $ee

%2. ,ombustion of pulveri


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&1. >tomish content in the co-e produced from a co-ing coal having 2Z ash may be around

(a) &Z (b) 2Z

(c)1+Z (")


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. Which of the following accentuates clin-ering trouble on furnace grate burning coal

(a) low density of carboni coal having high ratio of volatile matter to fi5ed carbon as compared to a coalhaving low ratio of volatile matter to fi5ed carbon

(a) is less liable to spontaneous combustion on storage(b) is more difficult to ignite and produces a shorter flame(c) reuires smaller combustion space and less secondary air(") &!&e !' $ee

2. Which of the following can be made into briuettes without the use of a binder

(a) /%7&%$e (b) bituminous coal

(c) anthracite coal (d) none of these

. Bresence of free moisture in coal is most disadvantageous during(a) %$ -/1e%za$%!& (a %$ e6%e +!e -!0e)(b) combustion of fine slac-s on the grates

(c) handling (e.g. when emptying wagons)(d) none of these

%. Which of the following is not a binder for coal briuetting?

(a) coal tar (b) bitumen

(c) molasses (") &!&e !' $ee

&. 8ighly ca-ing coals

(a) produce wea- co-e(b) produce strong co-e(c) may damage the co-e oven walls during carboni


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. !ncreases in ash content of blast furnace co-e

(a) reduces its consumption in the furnace(2) %eae %$ #!&+-$%!& %& $e '&a#e(c) does not affect its consumption in the furnace(d) decreases its hardness and abrasion resistance

. 8igh sulfur content in a fuel(a) increases the dew point of the flue gases(b) decreases the dew point of the flue gases(c) reduces combustion efficiency by limiting the permissible temperature reduction

of the flue gases(") 2!$ (a) a&" (#)

+. With the increase in carboni


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+&. Which of the following constituents of coal is most important in the production ofco-e

(a) moisture (b) ash

(c) volatiles (") #a2!&

+. Which of the following is most reactive (as regards the formation of ,D E 82from ,E 82D)?

(a) blast furnace co-e (2) /!0 $e+-ea$e #!3e

(c) anthracite coal (d) sub$bituminous coal

++. > coal that softens and fuses on heating in

(a) classified (b) carboni


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&. ,o-e oven gas compared to blast furnace gas is

(a) more e5plosive and inflammable (b) less poisonous(c) lighter (") a// (a), (2) a&" (#)

. Which of the following gases will reuire ma5imum amount of air for combustion of1 Hmgas?

(a) blast furnace gas (2) &a$a/ 7a

(c) producer gas (d) water gas

+. Which of the following will generate ma5imum volume of product of completecombustion (Hm/Hmof fuel)?

(a) carburetted water gas (b) blast furnace gas

(#) &a$a/ 7a (d) producers gas

. Which is the heaviest fuel gas out of the following?

(a) 2/a$ '&a#e 7a (b) co-e oven gas

(c) water gas (d) carburetted water gas

. N9uel can be defined as a substance which produces heat by

(a) combustion (b) nuclear fission

(c) nuclear fusion (") a// (a), (2) a&" (#)

. ,atalyst used in 9isher$6ropsch process is

(a) N%#3e/ (b) [inc o5ide

(c) >lumina (d) 6horium o5ide

1. !n the flue gas analysis by Drsat4s apparatus= o5ygen is absorbed by

(a) potassium hydro5ide (b) cuprous chloride

(#) a/3a/%&e -8!7a//!/ !/$%!& (d) none of these

2. !n flue gas analysis by Drsat4s apparatus= carbon dio5ide is absorbed by

(a) -!$a%+ 8"!5%"e (b) dilute potassium carbonate

(c) cuprous chloride (d) al-aline pyrogallol solution

. 6he seuence of absorption in flue gas analysis by Drsat4s apparatus is respectively

(a) CO, O, CO (b) ,D= D2= ,D2(c) ,D2= ,D= D2 (d) D2= ,D2= ,D

%. Which of the following has the highest calorific value?

(a) lignite (b) sub$bituminous coal

(#) a&$a#%$e (d) peat


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&. 6he main product of high temperature carboni


36/191

. ,ontact process (a) 8%e/" a#%" !' %7e #!e&$a$%!& $a& #a+2e -!#e (b) yields acids of lower concentration than chamber process

(c) is obsolete (d) eliminates absorber

%. 2Z Dleum means that in 1 lb.= there are 2 lb. of (a) SOa&" /2 !' HSO (b) 820D% and lb 0D (c) 0Dfor each 1 lb of 820D%

(d) 820D% and lb 0D&. Broducer gas consists mainly of (a) CO, CO, N, H

(b) ,D= 82(c) 82= ,8%(d) ,282= ,D2= 82

. D5ygen is produced by fraction of air using

(a) Iinde*s process(b) ,laude*s process(#) 2!$ L%&"e a&" C/a"e -!#e(d) Fayer*s process

+. Raw materials for *0olvay Brocess* for manufacture of the soda ash are(a) a/$, /%+e$!&e ,a++!&%a a&" #!3e !1e& 7a(b) ammonia= salt and limestone(c) ammonia= limestone and co-e(d) ammonia and co-e oven gas

. ;conomics of *0olvay Brocess\ depends upon the efficiency of(a) carbonating tower(b) ammonia recovery(#) a++!&%a e#!1e8 a&" %ze !' -/a&$(d) ammoniation of salt solution

. 3ercury cells for caustic soda manufacture compared to diaphragm cells(a) reuire lower initial investment(b) reuire more power(c) produce lower concentration of HaD8(") &!&e !' $ee

1. ,ement mainly contains(a)CaO, S%O, A/O

b (b) 3gD= 0iD2= L2D (c) >l2D= 3gD= 9e2D

(d) ,aD= 3gD= L2D11. ypsum is

(a) calcium chloride(b) potassium sulfate(c) sodium sulfate(") #a/#%+ /'a$e


37/191

12. lauber*s salt is(a) calcium sulfate(b) potassium sulfate(c) potassium chlorate(") !"%+ /'a$e "e#a8"a$e

1. Bermanent hardness of water is due to the presence of calcium and magnesium(a) bi$carbonates(2) /'a$e a&" #/!%"e(c) carbonate(d) chlorides

1%. Widely used method for conditioning of boiler feed water is(a) cold lime process(b) coagulation(#) !$/%+e !"a -!#e(d) seuestration

1&. 8ydra


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21. 0olvent used for e5traction of oil is(a) e5a&e(b) methyl ethyl -etone(c) furfural(d) ben


39/191

. Fuilders are added in soap to (a) 2!!$ #/ea&%&7 -!0eb (b) act as anti$redeposition agent

(c) act as corrosion inhibitor(d) acts as fabric brightener

1. Fio$degradable detergents(a) #a& 2e ea"%/8 !5%"%ze"(b) pose problem in sewerage plant(c) have an isoparaffinic structure(d) should not be used as it spoils the cloth

2. Which of the following is a detergent?(a) fatty alcohol(2) a/38/ 2e&ze&e /'!&a$e(c) fatty acids(d) methyl chloride

. Yellow glycerin is made into white= using

(a) a#$%1a$e" #a2!&(b) diatomaceous earth(c) bau5ite(d) bentonite

%. ;ssential oils are usually obtained using(a) $ea+ "%$%//a$%!&(b) e5tractive distillation(c) solvent e5traction(d) leaching

&. Blastici


40/191

. ;namels(a) 7%1e 7!!" 7/!8 '%&%(b) are same as varnish(c) are prepared from non$drying oil(d) do not contain pigment

%. 0D2is bubbled through hot sugar$cane Cuice to(a) a#$ a a& a#%"%'8%&7 a7e&$(b) increase its concentration(c) increase the amount of molasses(d) increase the crystal si


41/191

%. Fleaching of paper pulp is done with(a) activated clay(b) bromine(#) #/!%&e ! #/!%&e "%!5%"e(d) magnesium sulfite

%. 0i


42/191

&+. Mltimate analysis of coal determines(a) +!%$e, 8"!7e&, &%$!7e&, /'(b) carbon= ash= sulfur=nitrogen(c) carbon= sulfur= volatile matter= ash(d) carbon=volatile matter= ash= moisture

&. Washing of coal is done to(a) remove the inherent impurities(2) remove the adhering impurities(#) reduce the ash content(") 2!$ ba&" c

&. > good uality coal should have (a) low fusion point of ash

(b) high ash contentc (c) high sulfur contentd (") &!&e !' $ee. ,o-e oven gas consists mainly of

(a) H, CH (b) ,D= ,D2(c) 82= ,D(d) ,8%= ,D

1. Iurgi coal gasifier is a pressuri


43/191

. Lopper$6otcrylonitrile is mainly used in(a) -!/8+e %&"$8(b) printing industry(c) dyeing industry(d) photographic industry

. 6he maCor use of butadiene is (a) as a plastici


44/191

+&. AA6 stands(a) diethyl$diphenyl$trichloromethane(b) dichloro$diphenyl$trichloromethane(c) diphenyl$dichloro$trichloromethane(") "%#/!!"%-e&8/$%#/!!e$a&e

+. F8, (Fenntibiotic

(a) -!%2%$9"e$!8 $e 7!0$ !' +%#!!7a&%+ (b) is used as pain relievere (c) is an anti$malaria

(d) is an anaesthetic+. Benicillin is made employing

(a) continuous fermentation process(2) ae!2%# 2a$# 'e+e&$a$%!&(c) anaerobic batch fermentation(d) aerobic or anaerobic batch fermentation

. Which of the following is not an antibiotic?(a) penicillin(b) streptomycin(c) tetracyclin(") 6%&%&e

1. 3olecular weights of polymers are in the range of(a) 1 $ 1(b) 1&$ 1

(c) * *

(d) 1&$ 1+

2. [eigler process (a) -!"#e %7 "e&%$8 -!/8e$8/e&e

(b) produces low density polyethylene(c) uses no catalyst(d) employs very high pressure

. Boly$'inyl ,hloride (B',) is(a) thermosetting(2) $e+!-/a$%#(c) a fibrous material(d) chemically active


45/191

%. Bhenol formaldehyde(a) employs addition polymeri


46/191

. 6hermoplastic materials(a) do not soften on application of heat(b) are heavily branched molecules(c) are solvent insoluble(") ae #a-a2/e !' !'$e&%&7 ! '%&7 0e& ea$e" a&" !' a"e&%&7 a7a%& 0e&

#!!/e"%. 6hermosetting materials(a) ae #a-a2/e !' 2e#!+%&7 -e+a&e&$/8 %7%" 0e& ea$e" ! #e"(b) soften on application of heat(c) are solvent insoluble(d) are heavily branched molecules

&. 6ype of glass used in optical wor- is(a) soda$lime glass(b) fiber glass(#) /ea" 7/a(d) borosilicate glass

. 0ilicon carbide is(a) an adhesive(b) an abrasive(c) a type of glass(") 2%$$/e

+. 6he temperature in the calcium carbide furnace is(a) 2 $ ],(b) + $ &],(#) C(d) % $ %&],

. ,umene (!sopropyl ben


47/191

12. [eolite used in water softening process (cation e5change) is regenerated by washing withU

(a) 2%&e(b) chloramines(c) sodium bisulfite

(d) liuid chlorines1. Bresence of 820 in raw water (to be chlorinated) results in(a) reduced softening capacity of lum >l2(0D%)V is used as a coagulant in water treatment to remove(a) color(b) turbidity(c) bacteria(") a// a,b a&" c


48/191

111. Mse of hydrated lime in water treatment (a) before filtration= reduces the bacterial load on filters (b)after filtration= combats the corrosiveness of water due to presence of D2 and ,D2

(c) is to adCust the p8 value (") a// a,b a&" c

112. 6he purpose of adding Ha2,Dto water of low al-alinity is to (a) -e+%$ $e e !' a/+ a a #!a7/a&$ (b) increase the softening capacity of pplication of activated carbon reduces the temporary hardness of water (") N!+a//8, $e $2%"%$8 % e+!1e" 28 a""%&7 a #!a7/a&$ -%! $!

e"%+e&$a$%!&11%. Bic- out the false statement pertaining to water treatment (a) >eration of water is effective in ,D2 removalf (2) Te ze!/%$e 0a$e !'$e&%&7 -!#e e"#e $e a"&e !' 0a$e 28 &!$

+!e $a&


49/191

11. Dils are partially hydrogenated (not fully) to manufacture vanaspati= because fullysaturated solidified oils

(a) #ae #!/e$e!/ 2%/" - a&" 2/!!" #/!$$%&7 (b) are prone to rancid o5idation (c) always contain some amount of nic-el (as their complete removal is very

difficult) (d) have affinity to retain harmful sulfur compounds12. 8ydrogenation of oil ta-es place in

(a) an autothermal reactor(2) a $%#3/e 2e" ea#$!(c) a plug flow reactor(d) bac-mi5 reactor

121. 6emperature during hydrogenation of oil should not be more than 2],= otherwiseit will result in

(a) pyrolysis of oil(2) sintering of porous catalyst

(#) hydrogen embrittlement(") a// a,b a&" c122. 0having soaps are

(a) !'$ -!$a%+ !a- (-!$a%+ a/$ !' 'a$$8 a#%") 0%$ 'ee $ea%# a#%" $!7%1e /a$e a /a$%&7 -!-e$8

(b) metallic soaps compounded with frothing agents (c) high free al-ali soaps having e5cess of cane sugar and alcohol

(d) usually soap soaps12. 6ransparent soaps (e.g. Pears) are

(a) a//8 !'$ !a- (+a"e '!+ #!#!&$ !%/) %& 0%# #a&e 7a a&" a/#!!/ae a""e" a&" '%&a//8 0ae" 0%$ +e$8/a$e -%%$ $! a#%e1e $a&-ae

(b) metallic soaps with frothing agent and free stearic acid to achieve transparency (c) metallic soaps with frothing agent from which glycerin has not been recovered (d) high free al-ali soaps having e5cess of cane sugar and alcohol12%. lycerin is recovered from lye by

(a) e1a-!a$%!& '!//!0e" 28 1a#+ "%$%//a$%!& (b) liuid e5traction techniue

(c) e5tractive distillation techniue(d) steam distllation

12&. lycerin is not used in the (a) manufacture of e5plosive (b) conditioning and humidification of tobacco (c) manufacture of pharmaceuticals (") +a&'a#$e !' #a$%# !"a


50/191

FLO@ OF FLUIDS

1. > fluid is one which

(a) #a&&!$ e+a%& a$ e$ &"e $e a#$%!& !' ea '!#e(b) continuously e5pands till it fills any container(c) is incompressible(d) permanently resists distortion

2. !n an incompressible fluid density(a) is greatly affected by moderate changes in pressure(b) is greatly affected only by moderate changes in temperature(#) e+a%& &a''e#$e" 0%$ +!"ea$e #a&7e %& $e+-ea$e a&" -ee(d) is sensible to changes in both temperature and pressure

. Botential flow is the flow of(a) compressible fluids with shear(b) compressible fluids with no shear(c) incompressible fluids with shear(") %!+-e%2/e '/%" 0%$ &! ea

%. Botential flow is characteri


51/191

+. Boise is converted into sto-e by(a) multiplying with density (gm/c.c.)(2) "%1%"%&7 0%$ "e&%$8 (7+9#.#.)(c) multiplying with specific gravity

(d) dividing with specific gravity

. Aimension of -inematic viscosity is(a) 3I$2 (2) LT*

(c) I26 (d) I262

. With increase in the temperature viscosity of a liuid(a) increase (2) "e#eae(c) remains constant (d) first decreases and then increases

1. 9or water= when the pressure increases the viscosity(a) also increases (b) decreases(c) remains constant (") '%$ "e#eae a&" $e& %eae


52/191

11. 6he pressure intensity is the same in all direction at a point in a fluid(a) only when the fluid is frictionless(b) only when the fluid is at rest having


53/191

1+. 3ass velocity is the independent of temperature and pressure when the flow is(a) unsteady through uncharged cross$section(b) steady through changing cross$section(#) $ea"8 a&" $e #!e#$%!& % a&7e"

(d) unsteady ant the cross$section is changed1. !n turbulent flow

(a) the fluid particles move in an orderly manner(b) momentum transfer is on molecular scale only(c) shear stress is caused more effectively by cohesion than momentum transfer(") ea $ee ae 7e&ea//8 /a7e $a& %& a %+%/a /a+%&a '/!0

1. 6urbulant flow generally occurs for cases involving

(a) highly viscous fluid (b) very narrow passages

(c) very slow motion (") &!&e !' $ee2. >n ideal fluid is

(a) '%#$%!&/e a&" %!+-e%2/e(b) one which obeys Hewton4s law of viscosity(c) highly viscous (d) none of these

21.0teady flow occurs when(a) conditions change steadily with time(b) conditions are the same at the adCacent points at any instant(#) #!&"%$%!& "! &!$ #a&7e 0%$ $%+e a$ a&8 -!%&$(d) rate of change of velocity is constant

22. Which of the following must be followed by the flow of fluid (real or ideal)?(i) Hewton4s law of viscosity(ii) Hewton4s second law of motion(iii) the continuity euation(iv) velocity of boundary must be


54/191

2&. Fernoulli4s euation describes(a) +e#a&%#a/ e&e78 2a/ae %& -!$e&$%a/ '/!0(b) -inetic energy balance in laminar flow(c) mechanical energy balance in turbulent flow

(d) mechanical energy balance in boundary layer2. 6he -inetic energy correction factor for velocity distribution of laminar flow is

(a) .& (2) *.(c) 1 (d) 2

2+. 6he momentum correction factor for the velocity distribution of laminar flow is(a) 1. (b) 1.(c) 2.& (") &!&e !' $ee

2. 6he loss due to sudden e5pansion is

(a) '12

@ '22

2gc (2) (V*; V)

7C(#) '1@ '2 2gc

(d) none of these

2. 6he loss due to sudden contraction is proportional to(a) velocity (2) 1e/!#%$8 ea"(c) turbulence (d) none of these

. 6he value of critical Reynolds number for pipe flow is(a) * (b) 1=(c) 1= (d) none of these

1. Reynolds number flow of water at room temperature through 2 cm diameter pipe ataverage velocity of & cm/sec is around(a) 2 (b) 1(c) 1 (") *


55/191

2. 0hear stress in a fluid flowing in a round pipe(a) varies parabolically across the cross$section(b) remains constant over the cross$section

(#) % ze! a$ $e #e&$e a&" 1a%e /%&ea/8 0%$ $e a"%(d) is


56/191

. Reynolds number is the ratio of(a) viscous forces to gravity forces(2) %&e$%a/ '!#e $! 1%#! '!#e(c) viscous forces to inertial forces

(d) inertial forces to gravity forces%. 3ach. number is the ratio of the speed of the

(a) fluid of that of the light (b) light to that of the fluid(#) '/%" $! $a$ !' $e!&" (d) sound to that of the fluid

%1. Bower loss in an orifice meter is(a) less than that in a venturi meter

(b) same as that in a venturi meter(#) +!e $a& $a$ %& a 1e&$% +e$e(d) data insufficient= cannot be predicted

%2. 6he velocity profile for turbulent flow through a closed conduit is(a) /!7a%$+%# (b) parabolic(c) hyperbolic (d) linear

%. 9or laminar flow through a closed conduit(a) V+a5 4 Va1 (b) 'ma57 'av(c) 'ma57 1.& 'av (d) 'av 7 2 'ma5

%%.f 7 1/HReis valid for(a) turbulent flow(2) /a+%&a '/!0 $!7 a& !-e& #a&&e/(c) steady flow (d) none of these

%&. !sotropic turbulence occurs(a) 0ee $ee % &! 1e/!#%$8 7a"%e&$(b) at higher temperatures(c) only in newtonion fluid(d) none of these

%. ,onsider two pipes of same length and diameter through which water is passed at thesame velocity. 6he friction factor for rough pipe isf1and that for smooth pipe isf2.Bic- out the correct statement.(a)f17f2 (b)f1O f2(#)f*= f (d) data not sufficient to relatef1and f2


57/191

%+. Fernoulli4s euation for steady frictionless= continuous flow states that(a) total pressure at all sections is same(2) $!$a/ e&e78 a$ a// e#$%!& % a+e(c) velocity head at all section is same

(d) none of these%. Arag is defined as the force e5erted by the

(a) fluid on the solid in a direction opposite to flow(2) $e '/%" !& $e !/%" %& $e "%e#$%!& !' '/!0(c) the solid on the fluid (d) none of these

%. Arag co$efficient for flow past immersed body is the ratio of

(a) shear stress to the product of velocity head density(b) shear force to the product of velocity head and density(#) a1ea7e "a7 -e &%$ -!e#$e" aea $! $e -!"#$ !' 1e/!#%$8 ea" a&"

"e&%$8(d) none of these

&. 0to-e4s law is valid when the particle Reynolds number is(a) O 1 (b) G 1(#) < (d) none of these

&1. Arag co$efficient ,Ais given by (in 0to-e4s law range)(a) ,A 7 1 Re.p

(b) CD4 Re.-

(c) ,A7 1.%Re.p

(d) ,A7 .+ Re.p


58/191

&2. >t low Reynolds number(a) viscous forces are unimportant(b) viscous forces control(#) 1%#! '!#e #!&$!/ a&" %&e$%a/ '!#e ae &%+-!$a&$

(d) gravity forces control&. >t high Reynolds number

(a) %&e$%a/ '!#e #!&$!/ a&" 1%#! '!#e ae &%+-!$a&$(b) viscous forces predominate(c) inertial forces are unimportant and viscous forces control(d) none of these

&%. 9or flow of fluid through pac-ed bed= the superficial velocity is(a) /e $a& $e a1ea7e 1e/!#%$8 $!7 #a&&e/(b) more than the average velocity through channels

(c) dependent on the pressure drop across the bed(d) same as the average velocity through channels

&&. Bressure drop in a pac-ed bed for laminar flow is given by(a) !ze&8Ca+a& e6a$%!& (b) Fla-e$Blummer euation(c) Ieva4s euation (d) none of these

&. Bressure drop in a pac-ed bed for turbulent flow is given by(a) Lo


59/191

&+. 9orce acting on a particle settling in fluid are(a) gravitational and bouyant forces(b) centrifugal and drag forces(#) 7a1%$a$%!&a/ ! #e&$%'7a/, 2!8a&$ a&" "a7 '!#e(d) e5ternal= drag and viscous forces

&. 6erminal velocity is(a) a #!&$a&$ 1e/!#%$8 0%$ &! a##e/ea$%!&(b) a fluctuating velocity(c) attained after moving one$haft of total distance

(d) none of these&. !n hindered settling= particles are

(a) placed farther from wall(b) not affected by other particles and the wall(#) &ea ea# !$e (d) none of these

. Arag co$efficient in hindered settling is(a) lesser than in free settling(b) eual to that in free settling(c) not necessarily greater than in free settling(") 7ea$e $a& 'ee e$$/%&7

1. 9or the free settling of a spherical particle through a fluid= the slope of ,A@ log HRe=plot is(a) 1 (2) ;*(c) .& (d) @.&


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+. > fluid Cet discharging from a 2# diameter orifice has a diameter of 1.+ at its vena$contracta. 6he co$efficient of contraction is(a) 1. (2) .(c) .+ (d) none of these

+. 6he discharge through a '$notch weir varies as(a) 8/2 (b) 81/2

(#) H


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. 6he continuity euation(a) e/a$e +a '/!0 a$e a/!&7 a $ea+ $2e(b) relates wor- and energy(c) stipulates that Hewton4s second law of motion must be satisfied at every point in

the fluid(d) none of these

+. 9or a specific centrifugal air blower operating at constant speed and capacity thepower reuirement and pressure vary(a) directly as suares of gas density(2) "%e#$/8 a 7a "e&%$8(c) directly as suare root of density(d) inversely as gas density

. 9oot valves are provided in the suction line of a centrifugal pump to

(a) a1!%" -%+%&7 e1e8 $%+e 0e $a$ $e -+-(b) remove the contaminant present in the liuid(c) minimi


64/191

(a) atmospheric pressure (b) sub$atmospheric pressure(#) -ee "%''eee 2e$0ee& $0! -!%&$(d) none of these

. 'elocity distribution for flow between the fi5ed parallel plates(a) 1a%e -aa2!/%#a//8 a#! $e e#$%!&(b) is constant over the entire cross section(c) is , 2>, a&" #>

%. ,apacity of a rotary gear pump can be varied by(a) changing the speed of rotation(b) bleeding air into suction(c) bypassing liuid from the suction or discharge line(") a// a>, 2>, a&" #>

&. 9or liuid flow through a pac-ed bed= the superficial velocity as compared to averagevelocity through the channel in the bed is(a) more (2) /e(c) eual (d) independent of porosity


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. Reciprocating pumps compared to centrifugal pumps(a) deliver liuid at uniform pressure(b) can handle slurries more efficiently(#) ae &!$ 2e#$ $! a% 2%&"%&7

(d) can be operated with delivery valve closed+. > tube is specified by its

(a) thic-ness only (b) outer diameter(#) $%#3&e a&" !$e "%a+e$e 2!$ (d) inner diameter

. 9or pipes that must be bro-en at intervals for maintenance= the connector used shouldbe a(a) &%!& (b) tee

(c) reduce4s (d) elbow. !f more than two branches of pipes are to be connected at the same point= then use

(a) elbow (b) union(#) $ee (d) none of these

1. 6he most economical valve for use with large diameter pipes is(a) 2$$e'/8 1a/1e (b) globe valve(c) needle valve (d) none of these

11. Which of the following factors does not contribute to the pressure drop in apipeline?(a) velocity of liuid (b) si


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1&. While starting on a5ial flow pump= its delivery valve should be -ept(a) !-e& (b) closed(c) either open or closed (d) none of these

1. !dentification of pipelines carrying different liuids and gases is done by(a) diameter of the pipe (2) #!/! !' $e -%-e(c) the altitude of at which pipe is located (d) none of these

1+. > centrifugal pump has the following specifications:Bower @ % 8.B. 0peed @ rpm8ead @ meters 9low @ 1 liters/minutes

!f its speed is halved = then the new head will be(a) + (b) % m(c) m (d) &.& m

1. !n uestion Ho. 1+= the power consumed now will be

(a) .< H.P. (b) 2 8.B.(c) % 8.B. (d) 1 8.B.

1. !n uestion Ho. 1+= the new discharge will be(a)


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11. Aisc compensators are provided in large diameter gas carrying pipelines to(a) -eep the pipe in proper orientation(b) ma-e the pipe Coint lea-$proof(#) a##!&$ '! #!&$a#$%!&9 e5-a&%!& !' -%-e "e $! $e+-ea$e #a&7e !'

$e !&"%&7(d) account for pressure variation inside the pipelines

11%. Hominal Bipe 0i


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11. ,entrifugal pump can4t be used to pump(a) molten sodium (used as a coolant in 9ast Freeder Reactor)(b) moderately vegetable oil used in soap industry(#) $%#3 +!/$e& !a- a$ C

(d) none of the above

12. 'olute type of casing is provided in a centrifugal pump to(a) convert velocity head to pressure head(b) convert pressure head to velocity head(c) reduce the discharge fluctuation(") %eae $e "%#a7e

121. > pump operating under specific conditions delivers insufficient uantity of liuid.6his may be set right by(a) decreasing the si

122. Aelivery of insufficient uantity of liuid by a pump may be caused by(a) air lea- in the inlet (b) low rpm(c) too high a lift (") a// a>, 2> a&" #>

12. >ctual lift of pump always less than the theoretical lift and is limited by

(a) specific gravity and temperature of the liuid(b) lea-age and pressure decreasing at higher elevations(c) frictional resistance through pipes= fittings and passages(") a// a>, 2> a&" #>

12%. 9ill up the blan-Hominal si

FLO@ OF HEAT

1. > pipe carrying steam at about ^, traverses a room= the air being still at ^,. themaCor fraction of the heat loss will be by


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a. conduction to the still air b. convection to the airc. radiation to the surrounding d. conduction and convection put together

2. > satellite in space e5changes heat with its surroundings bya. ,onduction b. convectionc. Radiation d. conduction as well as convection

. 9or the same temperature drop in the temperature ranges of $%^, the heat flow rate

will be highest bya. ,onduction process b. convection processb. Radiation process d. other factors should be -nown before any

conclusion%. !n the cold season a person would prefer to be near a fire because

a. 6he conduction from the fire will be betterb. the convection will be better if he is near the firec. Airect unimpeded radiation will provide uic- warmthd. combined conduction and convection will be better

&. > finned tube hot water radiator with a fan blowing air over it is -ept in rooms duringwinter. 6he maCor portion of the heat transfer from radiator to air due toa. Radiation b. convectionc. ,onduction d. combined conduction and radiation

. 9or a specified heat input and a given volume which material will have the smallesttemperature rise (Mse data boo- if necessary)a. 0teel b. aluminumc. Water d. copper

+. When a hot metal piece is left to cool in the air the time rate of cooling of the outer layerwill bea. 0lower at start and faster near the endb. faster at start and slower near the endc. both rate will be the samed. this will depend on the material

. > thin blac- plate at temperature 6 receives radiation from a surface at 6emperature 6and radiates to a surface at 6. !f all surfaces are blac- at steady statea. (6$6)G(6$6) b. (6$6)O(6$6)c. (6$6)7(6$6) d. can be any one of a= b or c

. !n a slab under steady conduction if the thermal conductivity increases along thethic-ness= the temperatures gradient along the direction will becomea. 0teeper b. 9latter c. Remain constant d. either b or c depending on the heat flow rate

1. !n steady state conduction with variable thermal conductivity if the conductivitydecreases along the flow direction= then the temperature gradient along the flow directionwill becomea. Remain constant b. will become flatter c. Will become steeper d. either b or c depending on the heat flow rate

11. !n steady state conduction with variable thermal conductivity if the conductivitydecreases along the flow direction= then the temperature gradient along the flow directionwill becomea. 0teeper b. flatter c. Remain constant d. either of the three depending on heat flow rate

12. !n steady state conduction with thermal conductivity given by -7-(1E_) where _= isEve= a slab of given thic-ness and given temperature drop will conduct


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a. 3ore heat at lower temperature levelsb. 3ore heat at higher temperature levelsc. Will be the same as flow depends in the temperature dropd. Will be the same as flow depends on the thic-ness only

1. ,hoose the correct statement or statementsa. 6he thermal conductivity of gases decreases with temperature

b. 6he thermal conductivity of insulating solids increase with temperaturec. 6he thermal conductivity of good electrical conductors are generally lowd. 6he thermal conductivity variation is of low percentage in gases as compared to

solids1%. !n slab generating heat uniformly and at steady state convecting eually on both sides= the

temperature gradient willa. 9latten out as the distance from the centre increasesb. Fecome steeper as the distance from the centre increasesc. Will remain constantd. ,an be any of (a=b) or (c) depending the heat generation rate

1&. 9or the same linear si


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c. 6he temperature drop will be faster along the lengthd. 6he temperature drop along the length will be at a lower rate

22. !n a long fin if the parameter m7`(hB/k>) increases= other parameters being maintainedconstant then.a. 6he temperature variation along the length will be a lower rateb. 6he temperature drop along the length will be steeperc. 6he parameter m influences the heat flow onlyd. 6he temperature profile will remain the same

2. 9or a given sectional area of fin if the circumstances is increase by adopting differentgeometric shape then

a. 6he temperature variation along the fin length will be steeperb. 6he temperature variation along the fin length will be featterc. 6he circumference length does not affect the temperature changed. 6he circumference will only influence the heat convected

2%. !n a given fin configuration increase in conductivity willa. Aecrease the total heat flowb. Will affect only the temperature gradientc. !ncrease the total heat flowd. 8eat flow is influenced only by the base temperature and sectional area

2&. >n increase in convection coefficient over a fin willa. !ncrease effectiveness b. decrease effectivenessc. Aoes not influence effectiveness d. influences only the fin efficiency

2. !n the case of fins it is desirable to havea. >rea of section maintained constant along the lengthb. >rea of section reduced along the lengthc. >rea of section increased along the length

d. Fetter to vary the convection coefficient than the area2+. 9in effectiveness will be increased more by

a. 8aving a higher value of convection coefficientb. 8igher sectional areac. higher thermal conductivityd. longer circumference

2. !f a suare section fin is split longitudinally used as two finsa. 6he total heat flow will decreaseb. 6he total heat flow will increasec. 6he total heat flow remain constantd. 8eat flow may increase or decrease depending on the material used

2. 9or a given volume of material for use in a pin fin

a. Ionger the fin better the total heat flowb. 0horter the fin better the heat flowc. >s the volume is constant the heat flow will not changed. >s length is increased heat flow will increase and after some length will decrease

,hoose the correct statement or statements for nos. 1$ uestions

. a. !f the convection coefficient is low= it is not desirable to use a fin


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b. !f the conductivity is large= longer fin will be more effectivec. Blate fins of smaller thic-ness is better in the point of view of heat dissipationd. 9inned surface is desirable under conditions of boiling

1. a. aluminum fins are better because the material is lightb. a constant area fin provides the best (heat flow/weight) ratioc. on rare occasions the heat flow may be reduced by the addition of finsd. !f conductivity is high a short fin will be a good proportion

2. a. > constant temperature gradient along the length of a constant area fin is not possibleb. 6he temperature gradient= in circular section fin dissipating heat will increase along

the lengthc. Iongitudinal fins are less effective compared to annular finsd. 9ins at close pitch will give a high heat dissipating rate

. a. >n aluminum fin will be cooler at a given distance compared to a copper fin ofidentical section and other parameterb. >n aluminum fin will be hotter at a given distance compared to a copper fin of

identical section and other parameterc. >n aluminum fin of same configuration will dessipate more heat compared to copper

find. >n >luminum fin of same configuration will dessipate less heat compared to copper

fin%. 0emi infinite model van be adopt when

a. 6hic-ness of the solid is very largeb. 8eat diffusion is very slowc. 0hort time periodd. >ll of these

&. 8eating or cooling of a road surface can be analy


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. 6he response time of a thermocouple is the time ta-en for the temperature change to bea. .& of original temperature differenceb. 1/1.%1% of original temperature differencec. 1/e of original temperature differenced. Z of the original temperature difference

%. 6o ma-e thermocouple to respond uic-ly

a. 6he wire diameter should be largeb. ,onvection heat transfer coefficient should be high

%1. 8eat transfer ratea. Will be higher in turbulent flowb. Will be lower in turbulent flowc. Will depend on the fluidd. Will depend only on viscosity

%2. Husselt number isa. Ratio of viscous to inertia forcesb. Aimensionless heat transfer coefficientc. Ratio of conduction to convection resistanced. 0ignifies of velocity gradient at the surface

%. Reynolds number isa. Ratio of conduction to convection resistanceb. Ratio of buoyant to inertia forcesc. Ratio of viscous ratio to inertia forced. Ratio of heat conducted to the heat capacity

%%. Brandtl number isa. Ratio of buoyant force to inertia forceb. Ratio of conduction to convection resistancec. 0ignifies the temperature gradient at the surfaced. Ratio of molecular momentum diffusively to thermal diffusion

%&. 6he 0taton number isa. 6he dimensionless temperature gradient at the surface in convection

b. 3ass diffused to heat diffusedc. Aimensionless convection coefficientd. Wall heat transfer/ heat transfer convection

%. 6he convective heat transfer coefficient in laminar fow over a flat platea. !ncreases if a lighter fluid is usedb. !ncreases if a higher viscosity fluid is usedc. !ncreases if higher velocities are usedd. !ncreases with distance

%+. !n the boundary layer over a flat plate in laminar flow the velocity isa. [ero at the boundary layer thic-nessb. 0lowly decreases from the free stream to the solid surfacec. 0lowly increases from the free stream to the wall

d. Dnly temperature in the boundary layer will be different from that of free stream

%. >s viscosity of fluid increases the boundary layer thic-nessa. Will increaseb. Will decreasec. Will not changed. Will increase at medium values and then will decrease

%. 6he temperature gradient in the fluid flowing over a flat platea. Will be


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b. Will be positive at the surfacec. Will be very steep at the surfaced. Will be lways increases along the flowb. Aecreases= increases and decreasesc. !ncreases up to critical Reynolds number and then decreasesd. Aecreases up to critical Reynolds number and then increases

&%. !n laminar flow over a flat plate.a. 6he thermal boundary layer and hydrodynamic boundary layers are of eual thic-nessb. 6he thermal boundary layer is thic-er if the Brandtl number is less than onec. 6he thermal boundary layer is thic-er if the Brandt number is less than oned. 6he thermal layer is always thinner in the laminar region

&&. ,hoose the correct statement:a. 8igher the value of -inematic viscosity thinner will be the boundary layerb. 8igher the Brandtl number lower will be the thic-ness of thermal boundary layerc. 6he convective heat transfer coefficient will be lower in turbulent flow as compared to

laminar flowd. 6he boundary layer will thic-en as the free stream velocity increases

&. !n flow across a cylinder= the local Husselt number will be highest ata. ^ from the stagnation pointb. >t the stagnation pointc. >t ^, from the stagnation pointd. >t 1&^, from the stagnation point

&+. !n ban-s of the tubes heat transfer will be highesta. !n linear arrangement with suare pitchb. Iinear arrangement with lower longitudinal pitchc. 0taggered arrangement with eual pitchd. 0taggered arrangement with lower longitudinal pitch

&. ,hoose the correct statement in flow through pipesa. !n laminar flow= the e5it Husselt number in the fully developed condition is lower than

at entry


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b. !n laminar flow= the e5it Fusselt number in the fully developed condition is higher thatat entry

c. !n laminar flow= the Husselt remains constantd. !n laminar flow the Husslet at constant wall temperature is higher as compared to

Husselr constant heat flow&. !n flow through pipes for the same Reynolds number

a. 6he thermal entry length is longer for low Brandtl number fluidsb. 6he thermal entry length is longer for high Brandtl number fluidsc. Brandtl number does not influence the thermal entry lengthd. 6he thermal entry length affect is more pronounced only turbulent flow

. ,hoose the correct statement:a. 9low of air can be considered as hydrodynamic layer fully developed and thermallayer developingb. 9low of oils can be considered as 89A and thermal layer developingc. 9low of liuid metals can be considered as hydrodynamic layer fully developed and

thermal layer developingd. 9low of water can be considered as hydrodynamic layer fully developed and thermal

layer developing

1. !n pipe flow= the average convection coefficienta. Will be higher in rough pipesb. Will be higher in smooth pipesc. Roughness affects only pressure drop and not the convection coefficientd. Dnly Reynolds and Brandtl numbers influence the convection coefficient and not the

roughness2. !n pipe flow

a. 9or constant heat flow= the initial length is more effective compared to the end lengthb. 9or constant wall temperature the initial length are less effective compared to the end

lengthc. !n fully developed flow and constant wall temperature= the effective compared to the

end lengths

d. !n fully developed flow and constant heat flu5= the effectiveness decreases with length. ,hoose the correct statement:a. !n smooth pipes a laminar flow remains laminar all through the lengthb. in smooth pipes a laminar flow turns turbulent after a certain lengthc. 6he temperature profile in fully developed layer remains the samed. 6he velocity profile in a pipe flow is established at the entry

%. ,hoose the correct statement:a. Fuoyant forces and inertia forces only influence free convection heat transferb. 'iscous and Fuoyant forces only influence free convection heat transferc. 'iscous and inertia forces only influence free convection heat transferd. 'iscous= inertia and Fuoyant forces influence the heat transfer in free convection

&. !n free convection= the slope of the curve Hu vs r Br

a. !ncreases with increasing r Brb. Aecreases with increasing r Brc. !ncreases and then decreases with increasing r Brd. Aecreases and then increases with increasing r Br

. With increase in e5cess temperature the heat flu5 in boilinga. !ncrease continuouslyb. Aecrease and then increasesc. !ncreases then decreases and again increasesd. Aecreases then increases and again decreases


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+. !n nucleate pool boiling the heat flu5 depends ona. Dnly the material of the surfaceb. 3aterial and roughness of the surfacec. !ndependent of surfaced. 9luid and material and surface roughness

. 6he heat flow in nucleate pool boiling will be higher for

a. 8ori


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d. >ctual heat transfer/heat transfer when minimum heat capacity fluid goes through thema5imum temperature difference in the e5changer

+. ,ross flow e5changers are popularly used for heat transfera. Iiuid and liuidb. Iiuid and evaporating fluidc. ,ondensing fluid and liuid

d. as and gas or liuid and gas++. 6he minimum heat transfer area for a given situation is for

a. Barallel flowb. ,ounter flowc. ,ross flowd. 0hell and tube

+. 6he flow direction is immaterial in the case of heat e5change froma. Wet or saturated steam to waterb. Water to gasc. Dil to waterd. Dil to gas

+. 6he monochromatic emissive power of a blac- body with increasing wavelength

a. Aecreasesb. !ncreasesc. Aecreases= reaches a minimum and then increasesd. !ncreases= reaches a ma5imum and the decreases

. > gray surface is one of whicha. Reflectivity euals emissivityb. ;missivity euals transmissivityc. ;missivity is constantd. >bsorptivity euals reflectivity

1. >s the source temperature increases the wavelength at which the monochromaticemissive power is ma5imuma. Aecreases continuously

b. Aecreases then increasesc. !ncreases continuouslyd. !ncreases and then decreases

2. 6he directional emissivity for metallic surface isa. ,onstant from all over the angles from normalb. 3ore near the normal and less near the tangential directionc. 3ore near tangential direction compared to normal directiond. 6he distribution is affected more by temperature than by direction

. 9or non metallic insulating materials directional emissivitya. !s constant all over the angles from normalb. 3ore at near normal directions than at tangential directionc. Iess at near normal directions compared to tangential directiond. ,an be as case b or c depending on surface preparation

%. 0elective surfacea. Ao not follow Lirchhoff4s lawb. >dsorb only at definite wavelengthsc. ;mit only at definite wave bands


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d. >ll of these&. lasses are

a. Dpaue for high temperature radiationb. Dpaue for low temperature radiationc. 6ransparent at short wavelengthsd. 6ransparent at long wavelengths

e. Dpaue for low temperature radiation transparent at long wavelengths. 9or solar collectors the reuired surface characteristics combination is

a. 8igh emissivity and low absorptivityb. 8igh emissivity and high reflectivityc. 8igh reflectivity and high absorptivityd. Iow emissivity and high absorptivity

+. ;missivity of as body of a given composition depends ona. 0hape and temperatureb. Bartial pressure and shapec. Bartial pressure and temperatured. >ll of these

. 9or a given shape= partial pressure and temperature the emissivity of

a. Dis higher than that of Hb. His higher than that of Hc. Dis higher than that of ,Dd. ,Dis higher than that of D

. 6he combination which will give the highest gas emissivity isa. Iow partial pressure= higher temperature and larger thic-nessb. 8igher partial pressure= higher temperature and larger thic-nessc. 8igher partial pressure= lower temperature and larger thic-nessd. Iower partial pressure= lower temperature and larger thic-ness

. 6he value of shape factor will be highest whena. 6he surface are farther apartb. 6he surface are closer

c. 6he surface are smaller and closerd. 6he surface are larger and closer

1. > radiation shield should havea. 8igh emissivityb. 8igh absorptivityc. 8igh reflectivityd. 8igh emissive power

2. ,hooses the correct statement or statements

a. 8ighly reflecting surface is suitable for solar heat collection through flat platesb. 6he emissivity of smooth surface is higher compared to rough surface of the samematerial

c. 9or a given gas body= the emissivity will decrease with increase in temperatured. 0now has high emissivity

. ,hoose the correct statement or statementsa. 6he shape factor of small enclosed body with respect to the enclosing surface is


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c. > small opening from a large enclosure at constant temperature will provide blac-body radiation

d. Flac- paint is an e5ample of bloc- body%. 6he reciprocity theorem states

a. 979b. >97>9

c. >97>9d. 979

&. ,hoose the correct statement or statementsa. 9.79E9b. >9.7>9.E>9c. 9.79E9d. >.9..7>9..E>9..

. ,hoose the correct statement or statementsa. Radiosity is another name for emissive powerb. Radiation intensity is the flow per unit areac. Radiation intensity is the radiant energy per unit solid angled. !rradiation is the total radiant energy incident on a surface

+. ,hoose the correct statement or statementsa. ,onve5 surface have positive value for shape factor themselvesb. ,oncave surface have positive value for shape factor with themselvesc. 9lat surfaces have positive value for shape factor with themselvesd. !rregular surfaces have positive value for shape factor with themselves

. !f >7% and >72 and 97.2 thena. 97 .2b. 97.c. 97.%d. 97.1

DRYING

1. 6he vapor pressure e5erted by the moisture contained in a wet solid depends upon thea) nature of the moistureb) temperature

c) nature of the solid") a// a, 2, a&" #

2. 6o remove all the moisture from a wet solid reuires e5posure toa) -e'e#$/8 "8 a%b) highly humid airc) air at high temperatured) none of these


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. ,alcium ammonium nitrate (a fertili


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22. > solid material shows case hardening properties while drying. Which of thefollowingshould be controlled to control the drying process?a) flow rate of inlet airb) relative humidity of outlet air

c) humidity of inlet air") $e+-ea$e !' $e !/%"

2. ,apacity of a rotary dryer depends ona) its r.p.mb) its inclination with ground surface#) 2!$ a a&" 2d) neither a nor b

2%. >ir at a particular humidity is heated in a furnace. 6he new dew pointa) decreases

2) %eaec) depends on the e5tent of heatingd) remains unchanged

2&. 6he critical moisture content in case of drying indicatesa) 2e7%&&%&7 !' 'a//%&7 a$e -e%!"b) beginning of constant rate periodc) end of falling rate periodd) none of these

2. > slurry is to be dried to produce fla-y solid. Which dryer would you recommend?a) -a8 "8eb) drum dryerc) rotary dryerd) dielectric dryer

2+. 9or continuous drying of granular or crystalline material= the dryer used isa) tunnelb) tray#) !$a8d) none of these

2. >ll moisture in a non$hygroscopic material isUUmoisturea) freeb) euilibrium#) &2!&"d) bound


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c) density of the vapord) none of these

. !n saturated gas= thea) 1a-! % %& e6%/%2%+ 0%$ $e /%6%" a$ $e 7a $e+-ea$e

b) vapor is in euilibrium with the liuid at the room temperaturec) partial pressure of vapor euals the vapor pressure of the liuid at roomtemperature

d) none of these

%. Relative humidity is the ratio of thea) partial pressure of the vapor to the vapor pressure of the liuid at room

temperature2) -a$%a/ -ee !' $e 1a-! $! $e 1a-! -ee !' $e /%6%" a$ 7a

$e+-ea$ec) actual humidity to saturation humidity

d) none of these&. 6he percentage humidity is less than the relative humidity only at

a)


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. 6he dew point of a saturated gas phase euals thea) 7a $e+-ea$eb) room temperaturec) wet bulb temperature

d) none of these1. 0teady state temperature reached by a small amount of liuid evaporating into a large

amountof unsaturated vapor$gas mi5ture isa) dry$bulb temperature2) 0e$ 2/2 $e+-ea$ec) dew pointd) adiabatic saturation temperature

11. Ary bulb temperature of the gas is

a) less than the wet$bulb temperature2) 7ea$e $a& $e 0e$2/2 $e+-ea$ec) eual to the wet$bulb temperatured) none of these

12. 6he difference of wet bulb temperature and adiabatic saturation temperature ofunsaturatedmi5ture of any system isa) -!%$%1eb) negativec)


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d) atmospheric

1. ,ritical humidity of a solid salt means the humiditya) above which it will always become dampb) below which it will always stay dry

#) 2!$ a a&" 2d) above which it will always become dry and below which it will always stay damp.

1. Bercentage saturation isUUUU..the relative saturation.a) a/0a8 +a//e $a&b) always greater thanc) not related tod) none of these

2. Wet bulb and dry bulb temperatures become identical ata) *K a$a$%!& #1e

b) &Z saturation curvec) +Z saturation curved) none of these

21. Which of the following processes is followed by unsaturated air (with dry bulbtemperature12o, and relative humidity %+Z) passing through water spray washer (temperature ofwater being constant at %o,)?a) humidification onlyb) heating only#) 2!$ ea$%&7 a&" +%"%'%#a$%!&d) evaporative cooling

22. Which of the following remains constant during sensible cooling process?a) specific humidityb) partial pressure of vapor#) 2!$ a a&" 2d) neither a nor b

2. Auring sensible cooling processa) relative humidity decreasesb) relative humidity increasesc) wet bulb temperature increases") 2!$ 2 a&" #

2%. > mi5ture of 1Z ,8 vapor in air at 2&o, and +& mm 8g has a dew point of 2 o,.!ts dew point at o, and + mm 8g will be arounda) 21.+o,b) 2o,c) 2+.o,d) *.!C


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2&. Which of the following remains constant during evaporative cooling process withrecirculated water supply?a) relative humidityb) partial pressure of vapor

#) 0e$ 2/2 $e+-ea$ed) none of these

2. Aew point of a gas$vapor mi5turea) increases with temperature riseb) decreases with temperature rise#) "e#eae 0%$ %eae %& -eed) increases with increases in pressure

2+. Which of the following decreases during evaporative cooling process withrecirculated water

supply?a) wet bulb temperatureb) relative humidityc) partial pressure of vapor") &!&e !' $ee

2. Which of the following increases during evaporative cooling process withrecirculated watersupply?a) wet bulb temperatureb) relative humidityc) partial pressure of vapor") 2!$ 2 a&" #

2. 6he relative saturation of a partially saturated mi5ture of vapor and gas can beincreased bya) reducing the total pressure of the mi5tureb) increasing the total pressure of the mi5turec) reducing the temperature of the mi5ture") 2!$ 2 a&" #

. ,ondensation of a vapor$gas mi5ture Cust begin whena) p = Pb) p >Pc) p = Pwhere: p7 partial pressure of the vapor


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P7 vapor pres

che objective type questions compilation-dean medina 8-28-10

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