model question-1 of hydraulics for dae-ii

9
T-303 HYDRAULICS Time Allowed: 3 Hours Full Marks: 75 Answer to Question No.1 is compulsory and to be answered first, This answer is to be made in separate loose script(s) provided for the purpose. Maximum time allowed is 45 minutes, after which the loose answer scripts will be collected and fresh answer scripts for answering the remaining part of the question will be provided. On early submission of answer scripts of Question No.1,a student will get the remaining script earlier. Question No.1 is compulsory .Answer any five from Group-A, 1. A. Choose the correct answer from the given alternatives: 1x20 i) The specific weight of fresh water under normal conditions in SI units is - (a) 981 x 10 3 N/m 3 , (b)) 98.1 x 10 3 N/m 3 (c) 9.81 x 10 3 N/m 3 , (d) none of the above, ii) Surface tension is a phenomenon due to - (a) difference in magnitude between the forces due to adhesion and cohesion, (b) adhesion between liquid and solid molecules, (c) viscous force, (d) none of the above. iii) The hydrostatic law of pressure variation is expressed by - (a) P=Z/y, (b) P=YZ + constant, (c) P= constant, (d) none of the above. iv) Vacuum pressure at a flow section is - (a) a pressure measured by a Bourdon gauge, (b) a pressure indicated by a vacuum gauge, (c)always the pressure indicated by a differential manometer, (d) none of the above. v) The laminar flow is characterized by - (a) irregular motion of fluid particles, (b) high Reynolds number of flow, (c) fluid particles moving in layers parallel to the boundary surface, (d) none of the above. vi) The Hydraulic grade line is one which indicated the Variation of - (a) total energy of flow in the direction of flow, (b) piezometric head in the direction of flow, (c) elevation head in the direction flow, (d) none of the above. vii) The Darcy Weisbach friction factor f which is a direct measure of resistance to flow in pipes is dependent on - (a) roughness, height, diameter and velocity, (b) roughness, height, diameter, velocity and Kinematic viscosity, (c) relative roughness, diameter and viscosity, (d) none of the above.

Upload: sougata-das

Post on 18-Aug-2015

213 views

Category:

Documents


0 download

DESCRIPTION

questions

TRANSCRIPT

T-303 HYDRAULICSTime Allowed: 3 Hours Full Marks: 75Answer to Question No.1 is compulsory and to be answered first, This answer is to be made in separateloose script(s pro!ided for the p"rpose# $a%im"m time allowed is &' min"tes, after which the loose answerscripts will be collected and fresh answer scripts for answerin( the remainin( part of the )"estion will bepro!ided# *n earl+ s"bmission of answer scripts of ,"estion -o#.,a st"dent will (et the remainin( scriptearlier#Question No.1 is compulsory #Answer any five from Group-A, .#A#Choose the correct answer from the (i!en alternati!es/ .%01i The specific wei(ht of fresh water "nder normal conditions in SI "nits is 2 (a 34. % .15-6m5, (b 34#. % .15 -6m5 (c 3#4. % .15 -6m5, (d none of the abo!e, ii S"rfacetensionisa phenomenon d"e to 2 (a difference inma(nit"de betweentheforces d"e to adhesion and cohesion, (b adhesion between li)"id and solidmolec"les, (c !isco"s force, (d none of the abo!e#iii Theh+drostaticlawof press"re!ariationise%pressedb+2 (a 7896+,(b 78Y9:constant, (c 78 constant, (d none of the abo!e#i! ;ac""m press"re at a flow section is 2 (a a press"re meas"red b+ a eisbach friction factor f which is a direct meas"re of resistance to flow inpipes is dependent on 2 (a ro"(hness, hei(ht, diameter and !elocit+, (b ro"(hness,hei(ht, diameter, !elocit+ and ?inematic !iscosit+, (c relati!e ro"(hness, diameter and !iscosit+, (dnone of the abo!e#!iii The critical depth is the depth of flow at which /2 (a specific ener(+ is ma%im"m#(b the "nit dischar(e ) is minim"m (c specific ener(+ is minim"m# (d the @ro"den"mber is (reater than "nit+#i%The criticaldepth in a rectan("lar channelis (i!en b+ (a ()56(.60, (b()06(.6', (c ()56(.65, (d ()56(.65#% *pen channel flow is the one in which A (a closed cond"it is f"ll of flowin(li)"id(btheli)"idflowin(inaclosedcond"it hasafrees"rface, (cco!eredchannel flows f"ll "nder press"re# (d the solid bo"ndaries confinin( the flow areopen at top#%iH+dra"licall+efficient channel crosssectionisonewhich(ahastheminim"mh+dra"lic resistance# (b carries ma%im"mdischar(e "nder (i!encondition of slope, ro"(hness and flow area (c has the ma%im"m possible slopeconsistent with the topo(raph+ (d has the ma%im"m wetted perimeter%ii Re+noldBs n"mber is defined as the ratio of (a inertia force to (ra!it+ force (b!isco"s force to elastic force(c !isco"s force to (ra!it+ force (d) inertia force to !isco"sforce%iii Head lost in friction is (o!erned b+ (a Darc+Bs law (c Che=+Bs law (d @ro"deCs Law(e-one of these%i! @lowthro"(hapipetaDesplace d"eto2(a difference ofpress"rebetweendifferentsections of the pipeline,(b downward slope of the pipeline (c both (a and (b); (d noneof the abo!e%!Loss d"e to friction is treated as2 (a minor loss (b maEor loss (cmoderate loss(d) minim"m loss%!i @riction loss thro"(h a pipe flow indicates(aloss of head d"e to static coefficient offriction (b loss of head d"e to d+namic coefficient of friction (c loss of head d"e tos"rface hardness# (d loss of flow rate d"e to s"rface hardness of the pipe%!ii $inor losses in a pipe flow are those losses (a which can be ne(lected safel+ (b whichare ca"sed b+ frictional resistance (c which are ca"sed b+ local dist"rbances d"e to pipe fittin(s (d none of the abo!e#%!iii In a pipe of "niform diameter loss of head at e%it is (atwice that at inlet (b fo"r times that at inlet(cone2half at inlet (d same as that at inlet%i% The H#F#L# is/ a !elocit+ head below T#G#L# (b alwa+s slopin( downward in the direction of flow (c sometimes abo!e the T#G#L# (d !elocit+ head abo!e the T#G#L#%%T#G#L# indicates/ a onl+ dat"m head (b onl+ press"re head(ctotal head(d one of the abo!e#%%i StoDe is the "nit of2 (a !iscosit+ (b mass densit+(c Dinematic !iscosit+ (d none%%ii S"rfacetensionof li)"id(a increaseswitharea(b decreaseswithtemperat"re(cincreases with temperat"re (d none of the abo!e#%%iii S"rface tension has the "nits of (a force per "nit area (b force per "nit len(th (c forceper "nit !ol"me (d none of the abo!e%%i! Thepoint of applicationof res"ltant press"reonthes"rfaceis2(a centreofpress"re(bintensit+ of press"re (c centroid (d)none of these%%!HH Thecentreof press"realwa+s actsthecentreof (ra!it+of theimmerseds"rface#22(a abo!e (b) at (c below (d)canBt sa+%%!i A press"re of .1m of head of oil (specific (ra!it+ 1#4' is e)"al to (a) 4554' D-6m0(b)45#54' D-6m0(c 455#4' D-6m0(d) 4#554' D-6m0%%!ii 7ie=ometer cannot be"sedtomeas"re (a ne(ati!epress"re(b press"reof a(as (c press"re of a li)"id# (d both a I b%%!iii 7ei=ometer is s"itable for meas"rin((a !er+ low press"re of a li)"id(b moderatepress"re of a li)"id(c !er+ hi(h press"re of a li)"id (dnone%%i% $anometeriss"itableformeas"rin((a onl+lowpress"re (bbothhi(handlowpress"re(c onl+ hi(h press"re(d onl+ ne(ati!e press"re%%% Differential manometer is"sedtomeas"re(a differenceof press"rebetweentwopipes (bdifference of press"re between two points in the same pipeline(cdifferenceof press"reheadbetweentwopipelinespro!idedthe+containthesame li)"id(dall of the abo!eGROUP-A0 A differential manometer connected at the two points A and < in a pipe containin( an oil ofspecific(ra!it+ 1#4, shows a difference in merc"i+ le!els as .01mm# Determine the difference in press"res at the two points in terms of head of water and (m6cm0# 2.15 >rite short notes on an+ fo"r with labelled sDetches where it is necessar+ of the followin( 2(a !ena contracta, (b coefficient of !elocit+, (c coefficient of dischar(e, (d *rifice meter, (e 7itot T"be, (f ;ent"rimeter# 2.1& >ater flows o!er a rectan("lar weir .#'m wide at a depth of 01cm and afterwords passes thro"(h a trian("lar ri(ht an(led weir# @ind the depth of water thro"(h the trian("lar weir# Dischar(e coefficients for the rectan("lar and trian("lar weirs are 1#J0 and 1#'3 respecti!el+#2.1' >rite short notes on an+ fo"r of the followin( 2 (a H+dra"lic (radient lines for flow thro"(h pipes, (bH+dra"lic mean depth, (c ?"tterBs form"la, (d C;R (critical !elocit+ ratio, (e Critical!elocit+, (f s"b2critical flow#0#' K&J >ater flows at the rate of .1J cm56sec alon( a rectan("lar section of .#L'm width# Calc"late critical depth# @inal whether h+dra"lic E"mp will occ"r if the "pstream depth of water is 0' cm# >hat wo"ld be rise in water le!el and power lost if h+dra"lic E"mp occ"rsM2.1L A circ"lar plate of diameter 5m is immersed in water in s"ch a wa+ that its least and (reater depth from the free s"rface of water are .m and 5m respecti!el+ # @ind (i total force e%erted b+ water, (ii the positionto centre of press"re#2.14 (i >hat is Re+nolds -o# (ii Define Absol"te press"re I (a"(e press"re# (iii @ind the Dinematics !iscosit+ of a fl"id ha!in( specific (ra!it+ .#0 and !iscosit+ 'c720:&:&3 A head of water o!er anorifice of diameter .11mm is 'm# The water comin( o"t fromorifice is collectedin a circ"lar tanD of diameter 0m# The rise of water le!el in circ"lar tanDis1#&'min51sec#Alsotheco2ordinateof acertainpoint ontheEet ,meas"redfrom;enacontracta are .11cm hori=ontal '#0cm !ertical# @ind the h+dra"lic co2efficients#22.1.1 A Hori=ontal ;ent"rimeter with inlet diameter 51cm and throat diameter .'cm is "sed tomeas"re the flow of an oil of sp# Fr# 1#4 # The dischar(e thro"(h ;ent"rimeter is '1lts6sec#@ind the difference ofH(le!el #TaDe Cd 81#34#2 222.1HYDRAULICSTime Allowed: 3 Hours Full Marks: 75Answer to Question No.1 is compulsory and to be answered first, This answer is to be made in separateloose script(s pro!ided for the p"rpose# $a%im"m time allowed is &' min"tes, after which the loose answerscripts will be collected and fresh answer scripts for answerin( the remainin( part of the )"estion will be pro!ided#*n earl+ s"bmission of answer scripts of ,"estion -o#.,a st"dent will (et the remainin( script earlier#Question No.1 is compulsory #Answer any five from Group-A,Q.1.) i. Choose the correct answer from the (i!en alternati!es (an+ twent+/ .%0'ii. Ideal fl"idisonewhichisA(a# Compressible, possess!iscosit+ands"rfacetension(b#Incompressible and has no !iscosit+ and s"rface tension (c# Compressible, has no !iscosit+and s"rface tension (d# all the abo!eiii. In -ewtonian fl"id,shearstressis(adirectl+proportional to!elocit+(radient (bin!ersel+proportional to !elocit+ (radient(c e)"al to !elocit+ (radient (d noneiv. 7rintersinDisat+peof 2(a -ewtonianfl"id(beisbach form"la for head loss d"e to friction I its prob# Disc"ss *rificemeter# 22(5:5:&3# Desi(n an irri(ation canal with followin( data (. Dischar(e of the canal 8 0&c"mec#7ermissible mean !elocit+ 8 1#41 m6s#(0