c i v i l e n g i n e e r i n g - ies master publication · 2018-04-11 · c i v i l e n g i n e e...
TRANSCRIPT
C I V I L E N G I N E E R I N GESE TOPICWISE OBJECTIVE SOLVED
PAPER–II
FROM 1995-2018
IES MASTER PUBLICATION
UPSC Engineering Services Examination,
State Engineering Service Examination & Public Sector Examination.
Typeset at : IES Master Publication, New Delhi-110016
© No part of this booklet may be reproduced, or distributed in anyform or by any means, electronic, mechanical, photocopying, orotherwise or stored in a database or retrieval system without theprior permission of IES MASTER PUBLICATION, New Delhi.Violaters are liable to be legally prosecuted.
First Edition : 2016Second Edition : 2017Third Edition : 2018
ISBN :
IES MASTER PublicationF-126, (Lower Basement), Katwaria Sarai, New Delhi-110016Phone : 011-26522064, Mobile : 8010009955, 9711853908E-mail : [email protected], [email protected] : iesmasterpublications.com, iesmaster.org
Preface
It is an immense pleasure to present topic wise previous years solved paper ofEngineering Services Exam. This booklet has come out after long observation anddetailed interaction with the students preparing for Engineering Services Exam andincludes detailed explanation to all questions. The approach has been to provideexplanation in such a way that just by going through the solutions, students will beable to understand the basic concepts and will apply these concepts in solving otherquestions that might be asked in future exams.
Engineering Services Exam is a gateway to a immensly satisfying and high exposurejob in engineering sector. The exposure to challenges and opportunities of leading thediverse field of engineering has been the main reason for students opting for thisservice as compared to others. To facilitate selection into these services, availabilityof arithmetic solution to previous year paper is the need of the day. Towards this endthis book becomes indispensable.
Mr. Kanchan Kumar ThakurDirector–IES Master
1. Fluid Mechanics ........................................................................................ 001 – 194
2. Environmental Engineering ........................................................................ 195 – 360
3. Engineering Hydrology ............................................................................... 361 – 422
4. Soil Mechanics .......................................................................................... 423 – 604
5. Irrigation Engineering ................................................................................. 605 – 658
6. Highway Engineering ................................................................................. 659 – 728
7. Surveying .................................................................................................. 729 – 814
8. Railway Engineering .................................................................................. 815 – 846
9. Airport Engineering .................................................................................... 847 – 868
10. Dock and Harbour ..................................................................................... 869 – 882
11. Tunnel Engineering .................................................................................... 883 – 890
CONTENTS
Contents
1. Fluid Properties ---------------------------------------------------------------------------------------- 1 — 10
2. Hydrostatic Pressure --------------------------------------------------------------------------------- 11 — 18
3. Liquid in Relative Equilibrium -----------------------------------------------------------------------19 — 23
4. Buoyancy and Floatation ----------------------------------------------------------------------------24 — 28
5. Fluid Kinematics --------------------------------------------------------------------------------------29 — 40
6. Fluid Dynamics ----------------------------------------------------------------------------------------41 — 47
7. Weirs and Notches -----------------------------------------------------------------------------------48 — 57
8. Laminar Flow-------------------------------------------------------------------------------------------58 — 68
9. Turbulent Flow -----------------------------------------------------------------------------------------69 — 71
10. Boundary Layer Theory ------------------------------------------------------------------------------72 — 78
11. Drag and Lift --------------------------------------------------------------------------------------------79 — 88
12. Flow Through Pipes -------------------------------------------------------------------------------- 89 — 106
13. Modal Analysis and Dimensional Analysis --------------------------------------------------- 107 — 116
14. Open Channel Flow-------------------------------------------------------------------------------- 117 — 149
15. Hydraulic Machines ------------------------------------------------------------------------------ 150 — 194
(A) FLUID MECHANICS, OPEN CHANNEL FLOW, PIPE FLOW
Fluid Properties, Pressure, Thrust, Buoyancy: Flow Kinematics; Integration of flow equations,Flow measurement: Relative motion; Moment of momentum, Viscosity, Boundary layer andControl. Drag, Lift; dimensional Analysis. Modelling, Cavitation; Flow oscillations- Momentumand Energy principles in Open channel flow, Flow controls, Hydraulic jump. Flow sections andproperties, Normal flow. Gradually varied flow; Surges, flow development and losses in pipeflows. Measurements; Siphons, Surges and Water hammer; Delivery of Power Pipe networks.
(B) HYDRAULIC MACHINES AND HYDROPOWER
Centrifugal pumps, types, performance parameters, scaling, pumps in parallel; Reciprocatingpumps, air vessels, performance parameters; Hydraulic ram; Hydraulic turbines, types,performance parameters, controls, choice; Power house, classification and layout, storage,poundage, control of supply.
Syllabus
CHAPTER
Fluid Properties
1
1. Which one of the following pressure unitsrepresents the LEAST pressure?(a) millibar (b) mm of mercury(c) N/mm2 (d) kgf/cm2
2. The surface tension of water at 20°C is 75 ×10–3 N/m. The difference in the water surfacewithin and outside an open-ended capillarytube of 1mm internal bore, inserted at thewater surface would nearly be
(a) 5 mm (b) 10 mm(c) 15 mm (d) 20 mm
3. Match List-I (curves labelled A, B, C and Din figure) with List-II (types of fluid) andselect the correct answer:
List-I List-II
O
She
ar s
tress
Velocity gradient
D
C
B
A
1. Ideal plastic2. Ideal3. Non-Newtonian4. Pseudoplastic
5. Thixotropic
Code:A B C D
(a) 2 3 1 5(b) 3 2 1 5(c) 4 2 5 1(d) 2 3 5 1
4. Match List-I with List-II and select the correctanswer:
List-I List-II
A. Concentrated sugar 1. Dilatant fluidsolution
B. Sewage sludge 2. Bingham plastic fluidC. Blood 3. Pseudoplastic fluidD. Air 4. Newtonian fluid
Code:A B C D
(a) 1 2 3 4(b) 1 2 4 3(c) 2 1 3 4(d) 2 1 4 3
5. Match List-I (Definitions) wi thList-II (Properties) and select the correctanswer
Fluid Mechanics | 3
List-I List-IIA. Newtonian fluid 1. Frictionless and
incompressibleB. Ideal fluid 2. Viscosity invariant with
shear stressC. Thixotropic fluid 3. Viscosity decreases at
higher shear stressD. Rheological fluid 4. Viscosity increases at
higher shear stress
Code:A B C D
(a) 2 4 1 3(b) 3 1 4 2(c) 2 1 4 3(d) 3 4 1 2
6. Which one of the following statements iscorrect?
(a) Dynamic viscosity of water is nearly 50times that of air
(b) Kinematic viscosity of water is 30 timesthat of air
(c) Water in soil is able to rise aconsiderable distance above thegroundwater table due to viscosity
(d) Vapour pressure of a liquid is inverselyproportional to the temperature
7. Which of the following fluids can be classifiedas non-Newtonian?
1. Kerosene oil2. Diesel oil3. Human Blood4. Toothpaste5. Water
Select the correct answer using the codesgiven below :
(a) 1 and 2 (b) 3 and 4(c) 2 and 5 (d) 1 and 5
8. Assertion (A) : At the standard temperature,the kinematic viscosity of air is greater thanthat of water at same temperatureReason (R) : The dynamic viscosity of airat standard temperature is lower than thatof water at the same temperature.
9. A f lat plate of 0.15 m2 is pul led at20 cm/s relative to another plate, fixedat a distance of 0.02 cm from it with a fluidhaving 20.0014 Ns / m separating them.What is the power required to maintain themotion?
(a) 0.014 W (b) 0.021 W(c) 0.035 W (d) 0.042 W
10. Which one of the following expresses theheight of rise or fall of a liquid in a’ capillarytube?
(a)4wdcos (b)
cos4 w
(c)4 cos
wd
(d)wd
4 cos
w = Specific weight of the liquida = Angle of contact of the liquid surfaces = Surface tension
11. Match List-I (Curve identification in figure)with List-II (Nature of fluid) and select thecorrect answer using the codes given belowthe lists:’
4 | ESE Topicwise Objective Solved Paper-II 1995-2018
A
B
Shea
r stre
sses
C
D
Rate of shear deformation
List-I List-II
A. Curve A 1. NewtonianB. Curve B 2. DilatantC. Curve C 3. Ideal bingham plasticD. Curve D 4. Pseudo-plastic
Codes:A B C D
(a) 3 4 1 2(b) 2 4 1 3(c) 3 1 4 2(d) 2 1 4 3
12. Assertion (A) : The movement of twoblocks of wood welted with hot glue requiresgreater and greater effort as the glue is dryingup.Reason (R) : Viscosity of liquids variesinversely with temperature.
13. Which one of the following statements iscorrect?
(a) Local atmospheric pressure is alwayslesser than standard atmospheric pressure
(b) Local atmospheric pressure depends uponthe elevation of the locality only
(c) Standard atmospheric pressure is at sealevel
(d) A barometer reads the difference betweenlocal and standard atmospheric pressure
14. Poise has the unit of
(a) Dyne-cm/s2 (b) Dyne-cm/s
(c) Dyne-s/cm (d) Dyne-s/cm2
15. Which of the following statements is correct?
(a) Dynamic viscosity is the property of a fluidwhich is not in motion
(b) Surface energy is a fluid property givingrise to the phenomenon of capillarity inwater
(c) Cavitation results from the action of veryhigh pressure
(d) Real fluids have lower viscosity than idealfluids
16. Statement (I) : As temperature increases,viscosity of air decreases.
Statement (II) : As temperature increases,activity of the air molecules increases.
17. Statement (I): Fluid pressure is a scalarquantity.
Statement (II): Fluid thrust always actsdownwards.
18. The surface tension in a soap bubble of50 mm diameter with its inside pressure being2.5 N/m2 above the atmospheric pressure is
(a) 0.0125 N/m (b) 0.0156 N/m
(c) 0.2 N/m (d) 0.0312 N/m
19. The surface tension of water at 20°C is75 × 10–3 N/m. The difference in water surfacewithin and outside an open-ended capillary
Fluid Mechanics | 5
tube of 1mm internal bore, inserted at thewater surface, would nearly, be
(a) 7 mm (b) 11 mm
(c) 15 mm (d) 19 mm
20. Cavitation is likely to occur if
1. Pressure becomes very high
2. Temperature becomes low
3. Pressure at the specific points falls belowvapour pressure
4. Energy is released with the onset of a highintensity wave due to noise and vibration ofthe machine.
Which of the above statements are correct?
(a) 1 and 3 (b) 2 and 3
(c) 3 and 4 (d) 2 and 4
21. Statement (I): The shear strain graph for aNewtonian fluid is linear.
Statement (II): The coefficient of viscosity of the fluid is not a constant.
22. Which of the following statements are correct?
1. Depression of mercury in a capillary tubeis dependent on density and surfacetension.
2. Modelling of flow-induced drag on a shipis done invoking both of Froude number30. and Reynolds number.
3. Flow of a fluid in a narrow pipe is relatableto both Reynolds number and Cauchynumber.
4. Formation and collapse of a soap bubbleis analyzed through employing surfacetension and external pressure.
5. Flow over the downstream slope of anogee spillway can be affected by surfacetension.
Select the correct answer using the codesgiven below:
(a) 1, 2 and 4 only (b) 1, 3 and 5 only
(c) 2, 3 and 4 only (d) 3, 4 and 5 only
23. Statement (I) : In areas where extreme coldconditions are a regular feature, and more soparticularly in winter, it is necessary to uselighter oil for automobiles than in summer.
Statement (II) : 'Lighter' in Statement (I)refers to the oil density, which may beadjusted by admixtures.
24. The surface tension in a soap bubble of 20mm diameter, when the inside pressure is2.0 N/m2 above atmospheric pressure, is
(a) 0.025 N/m (b) 0.0125 N/m
(c) 5 × 10–3 N/m (d) 4.25 × 10–3 N/m
25. A jet of water has a diameter of 0.3 cm. Theabsolute surface tension of water is 0.072 N/m and atmospheric pressure is 101.2 kN/m2
The absolute pressure within the jet of waterwill be
(a) 101.104 kN/m2 (b) 101.152 kN/m2
(c) 101.248 kN/m2 (d) 101.296 kN/m2
26. A glass tube of 2.5 mm internal diameter isimmersed in oil of mass density 940 kg/m3
to a depth of 9 mm. If a pressure of 148 N/m2 is needed to from a bubble which is justreleased. What is the surface tension of theoil?
(a) 0.041 N/m (b) 0.043 N/m
(c) 0.046 N/m (d) 0.050 N/m
6 | ESE Topicwise Objective Solved Paper-II 1995-2018
1. (a)
2. (c)
3. (a)
4. (a)
5. (c)
11. (a)
12. (a)
13. (c)
14. (d)
15. (b)
26. (a)21. (c)
22. (a)
23. (c)
24. (c)
25. (c)
16. (d)
17. (c)
18. (b)
19. (c)
20. (c)
6. (a)
7. (b)
8. (b)
9. (d)
10. (c)
1. (a) 1 millibar = 10–3 × 105 N/m2 = 100 N/m2
1 mm of Hg = 10–3 m of Hg = 10–3 × 13.6 m of water
= 10–3 × 13.6 × 9810= 133.41 N/m2
1 N/mm2 = 106 N/m2
1Kgf/cm2 = –4 29.81N
10 m= 98.1 × 103 N/m2
2. (c) For equilibrium
22 r r h g
h = 3
3 32 2 75 10r g (10 10 10)
= 15×10–3 m
h = 15 mm
3. (a) Curve between shear stress () and velocitygradient (du/dy) is:
and u
dy
Shea
r Stre
ss
Velocity gradient
Thixotropic - Printer’s ink
Ideal Plastic (Bhingham Plastic,Toothpaste, Drillingmud)
Rheopectic
Pseudo - (Paint, Blood, Paper pulp)
Newtronian - (Water, Air, Gasoline)Dilatant (Solution with suspendedsand, Starch and butter)
Ideal Fluid
ElasticSolid
4. (a)(i) Dilatant Fluid: Shear thickening fluid e.g.,
Solution with suspended sand, conc. sugarsolution.
(ii) Pseudo Plastic Fluid: Shear thinning fluid.Apparent viscosity decrease with increasein velocity gradient e.g., blood, milk
(iii) Bingham Plastic/Ideal Plastic: It hassome initial strength beyond whichdeformation starts e.g., Toothpaste, Sewagesludge.
(iv) Newtonian fluid: Water, air, gasoline andoil.
Fluid Mechanics | 7
5. (c) Correct sequence should be (c).
Ideal fluid
Thixotropic(Printer Ink)
Ideal Plastic
Rheological fluid
Newtonian fluid
tPseudo plastic
(Mud slurries Blood)Dilatant (Butter,
ConcentratedSugar Solution)
n < 1,B = 0
n > 1, B =0
n = 1,B = 0
Yiel
dS
tress
n < 1, B0
n=1,B
0
n>1,B
0
dudy
O
General equation for fluid shear stress
=nduA B
dy
=n 1
Apparent viscosity
du duA Bdy dy
Now when B = 0,
n = 1 ... Newtonian fluid, viscosityinvariant of shear stress.
n > 1 ... Shear thickening fluid i.e.,apparent viscosity increaseswith increase in deformation
n < 1 ... Shear thinning i.e., apparentviscosity decreases withincrease in shear stress(Psedo plastic)
Now when B 0,
n = 1 ... Ideal Bingham fluid (toothpaste)
n > 1 ... Rheological fluid i.e., apparentviscosity increases withincrease in shear stress
n < 1 ... Thixotropic i.e., apparentviscosity decreases withincrease in shear stress.
6. (a) Dynamic viscosity of water is nearly 50times that of air.
w = 8.90 × 10–4 Pa.sec
air = 1.81 ×10–5 Pa.sec
w
air
=
4
58.90 10 49.17 501.81 10
Water in soil is able to rise a considerabledistance above ground water table due tocapillary action.
Vapour pressure increases with the increasein temperature
7. (b) Example of Newtonian fluid Keroseneoil, Air, Water, Diesel oil.Example of Non-Newtonian fluid Humanblood, Tooth paste etc.
8. (b) Dynamic viscosity of water is approximately50 times that of air, but density water isaround 850 times more than air so kinematicviscosity of air is more than that of waterand defined as
Kinematic viscosity = Dynamic viscosity
densityHence both the statements are correct butR is not the correct explanation of A.
9. (d) Power = force × velocity
= duA Vdy
= 2200.0014 0.15 20 100.02
= 0.042 W
10. (c)
Meniscus
glass tubeh d
8 | ESE Topicwise Objective Solved Paper-II 1995-2018
n = 1 ... Ideal Bingham fluid (toothpaste)
n > 1 ... Rheological fluid i.e., apparentviscosity increases withincrease in shear stress
n < 1 ... Thixotropic i.e., apparentviscosity decreases withincrease in shear stress.
12. (a) Viscosity of liquids varies inversely withtemperature so as the hot glue cools down(dry up) it’s viscosity increases so movementof two blocks of wood welted with hot gluewould require greater effort.
13. (c) The Standard atmospheric pressure is themean pressure at the Sea-level at 0°centigrade and at 45° latitude is equal to76 cm of Mercury, The localatmospheric pressure is measured bymercury barometer.
The figure below shows the relationbetween standard atmospheric pressure,local atmospheric pressure and gaugepressure.
Absolute pressure at A
Gauge pressure at A
Standard atmospheric
pressure Absolute pressure at B
Absolute zero or complete vaccum
Local atmospheric pressure
A
B
The barometric pressure depends upon thegeographical location of the place, itselevation above the sea level and also theweather condition and it is used to measurelocal atmospheric pressure
14. (d) Poise is the unit of dynamic viscosity inC.G.S.
1 poise = 0.1 Ns/m2
=5
4 20.1 10 Dynes s
10 cm
= Dyne-s/cm2
Surface tension force in upward direction= d cos ... (i)
Weight of the liquid in the downward direction
=2d h w
4
... (ii)
Equating (i) and (ii)
d cos =2d h w
4
h =4 cos
wd
... (iii)
11. (a) Correct sequence should be (c).
Ideal fluid
Thixotropic(Printer Ink)
Ideal Plastic
Rheological fluid
Newtonian fluid
tPseudo plastic
(Mud slurries Blood)Dilatant (Butter,
ConcentratedSugar Solution)
n < 1,B = 0
n > 1, B =0
n = 1,B = 0
Yiel
dS
tress
n < 1, B0
n=1,B
0
n>1,B
0
dudy
O
General equation for fluid shear stress
=nduA B
dy
=n 1
Apparent viscosity
du duA Bdy dy
Now when B = 0,n = 1 ... Newtonian fluid, viscosity
invariant of shear stress.n > 1 ... Shear thickening fluid i.e.,
apparent viscosity increaseswith increase in deformation
n < 1 ... Shear thinning i.e., apparentviscosity decreases withincrease in shear stress(Psedo plastic)
Now when B 0,
Fluid Mechanics | 9
15. (b)
Dynamic viscosity is the property of a fluidin motion.
Cavitation occurs when pressure falls belowvapour pressure.
Real fluids have viscosity while viscosity ofideal fluid is zero
Surface energy is the fluid property and isresponsible for phenomena such as surfacetension, capillarity.
16. (d) With an increase in temperature, there istypically an increase in the molecularinterchange as molecules move faster inhigher temperature. The gas viscosityincreases with temperature.
17. (c) Pressure is a scalar quantity. It has definedmagnitude but undefined direction.
18. (b) 2T 2 d p d
4
pdT8
2.5 .05T
8
= 0.0156 N/m
19. (c) h = 4d
= 3
3 34 75 10 30mm
9.81 10 1 10
If we take bore as radius then d = 2mm
h = 15 mm
20. (c) Cavitation occurs when at a point fluidtemperature gets too high or the fluidpressure becomes too low.
In cavitation, energy is released with thestart of a high intensity wave due to noiseand vibration of machine.
21. (c) Statement (I): The shear strain graph for aNewtonian fluid is linear.
Statement (II): The coefficient of viscosity of the fluid is not a constant.
22. (a) (1) Depression of mercury in capillary tube
= 2Tcos
r g
(2) In ship model we froude number and
Reynolds number both
VD C
V Cgy
(3) Flow of a fluid in a narrow pipe isrelatable to both reynolds number andweber number.
(4) In soap bubble
p = 8d
(5) Flow over the downstream slope of anogee spillway can not be affected bysurface tension.
So option (a) 1, 2 and 4 only.
23. (c) Oil is thin when heated and thickens as itis cooled even to the point that at very coldtemperature, oil would thicken such that, itno longer lubricate the engine. Thereforelighter viscosity motor oils is essential whenseason changes from summer to winter toprevent catastrophic engine failure.
24. (c) P = 8D
2N/m2 = 8
0.02
= 5 × 10–3 N/m
25. (c) dj = 0.3cm
water = 0.072 N/m
Patm = 101.2N/m2
P = 2 for jetD
Pjet–Patm= 2 2–2
2 0.072N / m 48N / m 0.048KN / m0.3 10
1 0 | ESE Topicwise Objective Solved Paper-II 1995-2018
Pjet = 101.2 + 0.048 = 101.248 KN/m2.
26. (a)
9mm
d =2.5 mmi
oil = 940 kg/m3
(Pi–P0) = 4D
Now P0 = 940 × 9.81 × 9 × 10–3 = 82.99N/m2
148 – 82.99 = –34
2.5 10
= –365.01 2.5 10 0.041N / m
4
