GATE Solved Question Papers for Chemical Engineering [CH] by AglaSem.Com

SOLVED PAPERS

GATECHEMICAL ENGINEERING (CH)

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A comprehensive study guide for GATE

CONTENTS

• Introduction• Question Paper Pattern• Design of Questions• Marking Scheme• Syllabus• Previous Year Solved Papers

o Solved Question Paper 2014o Answer Key 2014o Solved Question Paper 2013o Answer Key 2013o Solved Question Paper 2012o Answer Key 2012

Introduction

The Graduate Aptitude Test in Engineering (GATE) is the all India level examination

conducted by the Indian Institute of Science and seven Indian Institutes of Technology

(IITs).

A crucial part of GATE preparation is to solve and practice using previous year GATE

papers. Solving previous year GATE papers help the candidate in understanding the exam

pattern, knowing the level of difficulty of questions, and analyzing preparation.

While attempting to solve any previous year GATE paper, it is advisable that it is done in a

simulated test environment. This means, that the candidate sets a timer to countdown to

test time, makes sure there is no other distraction, and then sits down to take the test as if

he / she is in the exam hall. After attempting the paper, check how many questions you

could get right in the first attempt. Analyse the strong and weak areas of preparation, and

accordingly devise a study schedule or revision pattern. After going through those areas

where in the first attempt could not do well, try the next paper.

Almost all of the engineering colleges in India take admission in M.Tech courses on the

basis of GATE scores. Apart from that, PSUs also recruit students directly on this basis.

To score high in this elite examination is tough, but quite achievable.

GATE Previous Year Solved Papers by

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Question Paper Pattern

In all the papers, there will be a total of 65 questions carrying 100 marks, out of which 10

questions carrying a total of 15 marks are in General Aptitude (GA).

In the papers bearing the codes AE, AG, BT, CE, CH, CS, EC, EE, IN, ME, MN, MT, PI, TF and

XE, the Engineering Mathematics will carry around 13% of the total marks, the General

Aptitude section will carry 15% of the total marks and the remaining percentage of the

total marks is devoted to the subject of the paper.

In the papers bearing the codes AR, CY, EY, GG, MA, PH and XL, the General Aptitude

section will carry 15% of the total marks and the remaining 85% of the total marks is

devoted to the subject of the paper.

GATE would contain questions of two different types in various papers:

(i) Multiple Choice Questions (MCQ) carrying 1 or 2 marks each in all papers and

sections. These questions are objective in nature, and each will have a choice of four

answers, out of which the candidate has to mark the correct answer(s).

(ii) Numerical Answer Questions of 1 or 2 marks each in all papers and sections. For

these questions the answer is a real number, to be entered by the candidate using the

virtual keypad. No choices will be shown for this type of questions.


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Design of Questions

The questions in a paper may be designed to test the following abilities:

(i) Recall: These are based on facts, principles, formulae or laws of the discipline of the

paper. The candidate is expected to be able to obtain the answer either from his/her

memory of the subject or at most from a one-line computation.

(ii) Comprehension: These questions will test the candidate's understanding of the

basics of his/her field, by requiring him/her to draw simple conclusions from fundamental

ideas.

(iii) Application: In these questions, the candidate is expected to apply his/her

knowledge either through computation or by logical reasoning.

(iv) Analysis and Synthesis: In these questions, the candidate is presented with data,

diagrams, images etc. that require analysis before a question can be answered. A Synthesis

question might require the candidate to compare two or more pieces of information.

Questions in this category could, for example, involve candidates in recognising unstated

assumptions, or separating useful information from irrelevant information.


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Marking Scheme

For 1-mark multiple-choice questions, 1/3 marks will be deducted for a wrong answer.

Likewise, for2-marks multiple-choice questions, 2/3 marks will be deducted for a wrong

answer. There is no negative marking for numerical answer type questions.

General Aptitude (GA) Questions

In all papers, GA questions carry a total of 15 marks. The GA section includes 5 questions

carrying 1 mark each (sub-total 5 marks) and 5 questions carrying 2 marks each (sub-total

10 marks).

Question Papers other than GG, XE and XL

These papers would contain 25 questions carrying 1 mark each (sub-total 25 marks) and

30 questions carrying 2 marks each (sub-total 60 marks). The question paper will consist of

questions of multiple choice and numerical answer type. For numerical answer questions,

choices will not be given. Candidates have to enter the answer (which will be a real

number, signed or unsigned, e.g. 25.06, -25.06, 25, -25 etc.) using a virtual keypad. An

appropriate range will be considered while evaluating the numerical answer type

questions so that the candidate is not penalized due to the usual round-off errors.

GG (Geology and Geophysics) Paper

Apart from the General Aptitude (GA) section, the GG question paper consists of two parts:

Part A and Part B. Part A is common for all candidates. Part B contains two sections: Section

1 (Geology) and Section 2 (Geo-physics). Candidates will have to attempt questions in Part

A and either Section 1 or Section 2 in Part B.

Part A consists of 25 multiple-choice questions carrying 1-mark each (sub-total 25 marks

and some of these may be numerical answer type questions). Each section in Part B

(Section 1 and Section 2) consists of 30 multiple choice questions carrying 2 marks each

(sub-total 60 marks and some of these may be numerical answer type questions).

XE Paper (Engineering Sciences)


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In XE paper, Engineering Mathematics section (Section A) is compulsory. This section

contains 11 questions carrying a total of 15 marks: 7 questions carrying 1 mark each (sub-

total 7 marks), and 4 questions carrying 2 marks each (sub-total 8 marks). Some questions

may be of numerical answer type questions.

Each of the other sections of the XE paper (Sections B through G) contains 22 questions

carrying a total of 35 marks: 9 questions carrying 1 mark each (sub-total 9 marks) and 13

questions carrying 2 marks each (sub-total 26 marks). Some questions may be of

numerical answer type.

XL Paper (Life Sciences)

In XL paper, Chemistry section (Section H) is compulsory. This section contains 15

questions carrying a total of 25 marks: 5 questions carrying 1 mark each (sub-total 5 marks)

and 10 questions carrying 2-marks each (sub-total 20 marks). Some questions may be of


Each of the other sections of the XL paper (Sections I through M) contains 20 questions

carrying a total of 30 marks: 10 questions carrying 1 mark each (sub-total 10 marks) and 10

questions carrying 2 marks each (sub-total 20 marks). Some questions may be of


Note on Negative Marking for Wrong Answers

For a wrong answer chosen for the multiple choice questions, there would be negative

marking. For1-mark multiple choice questions, 1/3 mark will be deducted for a wrong

answer. Likewise, for 2-mark multiple choice questions, 2/3 mark will be deducted for a

wrong answer. However, there is no negative marking for a wrong answer in numerical

answer type questions.


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Syllabus for General Aptitude (GA)

Verbal Ability: English grammar, sentence completion, verbal analogies, word groups,

instructions, critical reasoning and verbal deduction.

Numerical Ability: Numerical computation, numerical estimation, numerical reasoning

and data interpretation.

Syllabus for Chemical Engineering (CH)

ENGINEERING MATHEMATICS

Linear Algebra: Matrix algebra, Systems of linear equations, Eigen values and

eigenvectors.

Calculus: Functions of single variable, Limit, continuity and differentiability, Mean value

theorems, Evaluation of definite and improper integrals, Partial derivatives, Total

derivative, Maxima and minima, Gradient, Divergence and Curl, Vector identities,

Directional derivatives, Line, Surface and Volume integrals, Stokes, Gauss and Green’s

theorems.

Differential equations: First order equations (linear and nonlinear), Higher order linear

differential equations with constant coefficients, Cauchy’s and Euler’s equations, Initial

and boundary value problems, Laplace transforms, Solutions of one dimensional heat

and wave equations and Laplace equation.

Complex variables: Analytic functions, Cauchy’s integral theorem, Taylor and Laurent

series, Residue theorem.

Probability and Statistics: Definitions of probability and sampling theorems,

Conditional probability, Mean, median, mode and standard deviation, Random

variables, Poisson, Normal and Binomial distributions.

Numerical Methods: Numerical solutions of linear and non-linear algebraic equations

Integration by trapezoidal and Simpson’s rule, single and multi-step methods for

differential equations.

CHEMICAL ENGINEERING

Process Calculations and Thermodynamics: Laws of conservation of mass and

energy; use of tie components; recycle, bypass and purge calculations; degree of

freedom analysis. First and Second laws of thermodynamics. First law application to


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close and open systems. Second law and Entropy. Thermodynamic properties of pure

substances: equation of state and departure function, properties of mixtures: partial

molar properties, fugacity, excess properties and activity coefficients; phase equilibria:

predicting VLE of systems; chemical reaction equilibria.

Fluid Mechanics and Mechanical Operations: Fluid statics, Newtonian and non-

Newtonian fluids, Bernoulli equation, Macroscopic friction factors, energy balance,

dimensional analysis, shell balances, flow through pipeline systems, flow meters,

pumps and compressors, packed and fluidized beds, elementary boundary layer

theory, size reduction and size separation; free and hindered settling; centrifuge and

cyclones; thickening and classification, filtration, mixing and agitation; conveying of

solids.

Heat Transfer: Conduction, convection and radiation, heat transfer coefficients, steady

and unsteady heat conduction, boiling, condensation and evaporation; types of heat

exchangers and evaporators and their design.

Mass Transfer: Fick’s laws, molecular diffusion in fluids, mass transfer coefficients, film,

penetration and surface renewal theories; momentum, heat and mass transfer

analogies; stagewise and continuous contacting and stage efficiencies; HTU & NTU

concepts design and operation of equipment for distillation, absorption, leaching,

liquid-liquid extraction, drying, humidification, dehumidification and adsorption.

Chemical Reaction Engineering: Theories of reaction rates; kinetics of homogeneous

reactions, interpretation of kinetic data, single and multiple reactions in ideal reactors,

non-ideal reactors; residence time distribution, single parameter model; non-

isothermal reactors; kinetics of heterogeneous catalytic reactions; diffusion effects in

catalysis.

Instrumentation and Process Control: Measurement of process variables; sensors,

transducers and their dynamics, transfer functions and dynamic responses of simple

systems, process reaction curve, controller modes (P, PI, and PID); control valves;

analysis of closed loop systems including stability, frequency response and controller

tuning, cascade, feed forward control.

Plant Design and Economics: Process design and sizing of chemical engineering

equipment such as compressors, heat exchangers, multistage contactors; principles of


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process economics and cost estimation including total annualized cost, cost indexes,

rate of return, payback period, discounted cash flow, optimization in design.

Chemical Technology: Inorganic chemical industries; sulfuric acid, NaOH, fertilizers

(Ammonia, Urea, SSP and TSP); natural products industries (Pulp and Paper, Sugar, Oil,

and Fats); petroleum refining and petrochemicals; polymerization industries;

polyethylene, polypropylene, PVC and polyester synthetic fibers.


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GATEPrevious Year Solved Papers

Chemical Engineering - CH

2012 - 14


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Duration: 180 minutes Maximum Marks: 100

Read the following instructions carefully.

1. To login, enter your Registration Number and password provided to you. Kindly go through the various

symbols used in the test and understand their meaning before you start the examination.

2. Once you login and after the start of the examination, you can view all the questions in the question

paper, by clicking on the View All Questions button in the screen.

3. This question paper consists of 2 sections, General Aptitude (GA) for 15 marks and the subject

specific GATE paper for 85 marks. Both these sections are compulsory.

The GA section consists of 10 questions. Question numbers 1 to 5 are of 1-mark each, while question

numbers 6 to 10 are of 2-mark each.

The subject specific GATE paper section consists of 55 questions, out of which question numbers 1 to

25 are of 1-mark each, while question numbers 26 to 55 are of 2-mark each.

4. Depending upon the GATE paper, there may be useful common data that may be required for

answering the questions. If the paper has such useful data, the same can be viewed by clicking on the

Useful Common Data button that appears at the top, right hand side of the screen.

5. The computer allotted to you at the examination center runs specialized software that permits only one

answer to be selected for multiple-choice questions using a mouse and to enter a suitable number for

the numerical answer type questions using the virtual keyboard and mouse.

6. Your answers shall be updated and saved on a server periodically and also at the end of the

examination. The examination will stop automatically at the end of 180 minutes.

7. In each paper a candidate can answer a total of 65 questions carrying 100 marks.

8. The question paper may consist of questions of multiple choice type (MCQ) and numerical answer

type.

9. Multiple choice type questions will have four choices against A, B, C, D, out of which only ONE is the

correct answer. The candidate has to choose the correct answer by clicking on the bubble (⃝) placed

before the choice.

10. For numerical answer type questions, each question will have a numerical answer and there will not be

any choices. For these questions, the answer should be enteredby using the virtual keyboard that

appears on the monitor and the mouse.

11. All questions that are not attempted will result in zero marks. However, wrong answers for multiple

choice type questions (MCQ) will result in NEGATIVE marks. For all MCQ questions a wrong

answer will result in deduction of⅓ marks for a 1-mark question and ⅔ marks for a 2-mark question.

12. There is NO NEGATIVE MARKING for questions of NUMERICAL ANSWER TYPE.

13. Non-programmable type Calculator is allowed. Charts, graph sheets, and mathematical tables are NOT

allowed in the Examination Hall. You must use the Scribble pad provided to you at the examination

centre for all your rough work. The Scribble Pad has to be returned at the end of the examination.

Declaration by the candidate:

“I have read and understood all the above instructions. I have also read and understood clearly the

instructions given on the admit card and shall follow the same. I also understand that in case I am found to

violate any of these instructions, my candidature is liable to be cancelled. I also confirm that at the start of

the examination all the computer hardware allotted to me are in proper working condition”.


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GATE 2014 Solved Paper

Chemical Enginnering - CH

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Q. 1 – Q. 5 carry one mark each.

Q.1 A student is required to demonstrate a high level of comprehension of the subject, especially in the

social sciences.

The word closest in meaning to comprehension is

(A) understanding (B) meaning (C) concentration (D) stability

Q.2 Choose the most appropriate word from the options given below to complete the following

sentence.

One of his biggest ______ was his ability to forgive.

(A) vice (B) virtues (C) choices (D) strength

Q.3 Rajan was not happy that Sajan decided to do the project on his own. On observing his

unhappiness, Sajan explained to Rajan that he preferred to work independently.

Which one of the statements below is logically valid and can be inferred from the above sentences?

(A) Rajan has decided to work only in a group.

(B) Rajan and Sajan were formed into a group against their wishes.

(C) Sajan had decided to give in to Rajan’s request to work with him.

(D) Rajan had believed that Sajan and he would be working together.

Q.4 If y = 5x2 + 3, then the tangent at x = 0, y = 3

(A) passes through x = 0, y = 0 (B) has a slope of +1

(C) is parallel to the x-axis (D) has a slope of −1

Q.5 A foundry has a fixed daily cost of Rs 50,000 whenever it operates and a variable cost of Rs 800Q,

where Q is the daily production in tonnes. What is the cost of production in Rs per tonne for a daily

production of 100 tonnes?

Q. 6 – Q. 10 carry two marks each.

Q.6 Find the odd one in the following group: ALRVX, EPVZB, ITZDF, OYEIK

(A) ALRVX (B) EPVZB (C) ITZDF (D) OYEIK

Q.7 Anuj, Bhola, Chandan, Dilip, Eswar and Faisal live on different floors in a six-storeyed building

(the ground floor is numbered 1, the floor above it 2, and so on). Anuj lives on an even-numbered

floor. Bhola does not live on an odd numbered floor. Chandan does not live on any of the floors

below Faisal’s floor. Dilip does not live on floor number 2. Eswar does not live on a floor

immediately above or immediately below Bhola. Faisal lives three floors above Dilip. Which of the

following floor-person combinations is correct?

Anuj Bhola Chandan Dilip Eswar Faisal

(A) 6 2 5 1 3 4

(B) 2 6 5 1 3 4

(C) 4 2 6 3 1 5

(D) 2 4 6 1 3 5

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Q.8 The smallest angle of a triangle is equal to two thirds of the smallest angle of a quadrilateral. The

ratio between the angles of the quadrilateral is 3:4:5:6. The largest angle of the triangle is twice its

smallest angle. What is the sum, in degrees, of the second largest angle of the triangle and the

largest angle of the quadrilateral?

Q.9 One percent of the people of country X are taller than 6 ft. Two percent of the people of country Y

are taller than 6 ft. There are thrice as many people in country X as in country Y. Taking both

countries together, what is the percentage of people taller than 6 ft?

(A) 3.0 (B) 2.5 (C) 1.5 (D) 1.25

Q.10 The monthly rainfall chart based on 50 years of rainfall in Agra is shown in the following figure.

Which of the following are true? (k percentile is the value such that k percent of the data fall below

that value)

(i) On average, it rains more in July than in December

(ii) Every year, the amount of rainfall in August is more than that in January

(iii) July rainfall can be estimated with better confidence than February rainfall

(iv) In August, there is at least 500 mm of rainfall

(A) (i) and (ii) (B) (i) and (iii)

(C) (ii) and (iii) (D) (iii) and (iv)

END OF THE QUESTION PAPER

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Q.1 Gradient of a scalar variable is always

(A) a vector (B) a scalar (C) a dot product (D) zero

Q.2 For the time domain function 2( )f t t= , which ONE of the following is the Laplace transform of

0

( ) ?

t

f t dt∫

(A) 4

3

s (B)

2

1

4s (C)

3

2

s (D)

4

2

s

Q.3 If *( )f x is the complex conjugate of ( ) cos( ) sin( )f x x i x= + , then for real a and b,

*( ) ( )

b

a

f x f x dx∫ is ALWAYS

(A) positive (B) negative (C) real (D) imaginary

Q.4 If ( )f x is a real and continuous function of x, the Taylor series expansion of ( )f x about its

minima will NEVER have a term containing

(A) first derivative (B) second derivative (C) third derivative (D) any higher derivative

Q.5 From the following list, identify the properties which are equal in both vapour and liquid phases at

equilibrium

P. Density Q. Temperature

R. Chemical potential S. Enthalpy

(A) P and Q only (B) Q and R only (C) R and S only (D) P and S only

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Q.6 In a closed system, the isentropic expansion of an ideal gas with constant specific heats is

represented by

(A)

(B)

(C)

(D)

Q.7 Match the following

Group 1

Group 2

P.

, , j ii T P n

G

n≠

∂ ∂

I. Arrhenius equation

Q. , , j i

i S V n

G

n≠

∂ ∂

II. Reaction equilibrium constant

R.

0

exp reactionG

RT

−∆

III. Chemical potential

S. ,( ) 0i i T Pn dµ =∑

IV. Gibbs-Duhem equation

(A) Q─III, R─I, S─II

(B) Q─III, R─II, S─IV

(C) P─III, R─II, S─IV

(D) P─III, R─IV, S─I

P

V

P

V

ln(P)

ln(V)

ln(P)

ln(V)

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Q.8 In order to achieve the same conversion under identical reaction conditions and feed flow rate for a

non-autocatalytic reaction of positive order, the volume of an ideal CSTR is

(A) always greater than that of an ideal PFR

(B) always smaller than that of an ideal PFR

(C) same as that of an ideal PFR

(D) smaller than that of an ideal PFR only for first order reaction

Q.9 Integral of the time-weighted absolute error (ITAE) is expressed as

(A) 2

0

( )tdt

t

ε∞

∫ (B)

0

( )tdt

t

ε∞

∫ (C) 0

( )t t dtε∞

∫ (D) 2

0

( )t t dtε∞

∫

Q.10 A unit IMPULSE response of a first order system with time constantτ and steady state gain pK is

given by

(A) /1 t

p

eK

ττ

(B) /t

pK e τ− (C)

/tpK e ττ −

(D) /p tK

e ττ

−

Q.11 In a completely opaque medium, if 50% of the incident monochromatic radiation is absorbed, then

which of the following statements are CORRECT?

P. 50% of the incident radiation is reflected

Q. 25% of the incident radiation is reflected

R. 25% of the incident radiation is transmitted

S. No incident radiation is transmitted

(A) P and S only (B) Q and R only (C) P and Q only (D) R and S only

Q.12 In case of a pressure driven laminar flow of a Newtonian fluid of viscosity (µ) through a horizontal

circular pipe, the velocity of the fluid is proportional to

(A) µ (B)

0.5µ (C) 1µ −

(D) 0.5µ −

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Q.13 Which of the following statements are CORRECT?

P. For a rheopectic fluid, the apparent viscosity increases with time under a constant applied

shear stress

Q. For a pseudoplastic fluid, the apparent viscosity decreases with time under a constant applied

shear stress

R. For a Bingham plastic, the apparent viscosity increases exponentially with the deformation rate

S. For a dilatant fluid, the apparent viscosity increases with increasing deformation rate

(A) P and Q only (B) Q and R only (C) R and S only (D) P and S only

Q.14 Assume that an ordinary mercury-in-glass thermometer follows first order dynamics with a time

constant of 10 s. It is at a steady state temperature of 0 °C. At time t = 0, the thermometer is

suddenly immersed in a constant temperature bath at 100 °C. The time required (in s) for the

thermometer to read 95 °C, approximately is

(A) 60 (B) 40 (C) 30 (D) 20

Q.15 Packed towers are preferred for gas-liquid mass transfer operations with foaming liquids because

(A) in packed towers, high liquid to gas ratios are best handled

(B) in packed towers, continuous contact of gas and liquid takes place

(C) packed towers are packed with random packings

(D) in packed towers, the gas is not bubbled through the liquid pool

Q.16 A spherical storage vessel is quarter–filled with toluene. The diameter of the vent at the top of the

vessel is 1/20th of the diameter of the vessel. Under the steady state condition, the diffusive flux of

toluene is maximum at

(A) the surface of the liquid

(B) the mid-plane of the vessel

(C) the vent

(D) a distance 20 times the diameter of the vent away from the vent

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Q.17 In order to produce fine solid particles between 5 and 10 µm, the appropriate size reducing

equipment is

(A) fluid energy mill (B) hammer mill

(C) jaw crusher (D) smooth roll crusher

Q.18 Slurries are most conveniently pumped by a

(A) syringe pump (B) diaphragm pump

(C) vacuum pump (D) gear pump

Q.19 Assuming the mass transfer coefficients in the gas and the liquid phases are comparable, the

absorption of CO2 from reformer gas (CO2+H2) into an aqueous solution of diethanolamine is

controlled by

(A) gas phase resistance (B) liquid phase resistance

(C) both gas and liquid phase resistances (D) composition of the reformer gas

Q.20 Which ONE of the following statements is CORRECT for the surface renewal theory?

(A) Mass transfer takes place at steady state

(B) Mass transfer takes place at unsteady state

(C) Contact time is same for all the liquid elements

(D) Mass transfer depends only on the film resistance

Q.21 Steam economy of a multiple effect evaporator system is defined as

(A) kilogram of steam used per hour

(B) kilogram of steam consumed in all the effects for each kilogram of steam fed

(C) kilogram of steam used in all the effects for each kilogram of water vaporized per hour

(D) kilogram of water vaporized from all the effects for each kilogram of steam fed to the first

effect

Q.22 Decomposition efficiency (ηD) of an electrolytic cell used for producing NaOH is defined as

(A) ηD = (grams of NaOH produced / grams of NaCl decomposed) x 100

(B) ηD = (grams of NaOH produced / grams of NaCl charged) x 100

(C) ηD = (gram equivalents of NaOH produced / gram equivalents of NaCl charged) x 100

(D) ηD = (theoretical current to produce one gram equivalent / actual current to produce one gram

equivalent) x 100

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Q.23 The vessel dispersion number for an ideal CSTR is

(A) ─1 (B) 0 (C) 1 (D) ∞

Q.24 Catalytic cracking is

(A) a hydrogen addition process

(B) a carbon rejection process

(C) an exothermic process

(D) a coking process

Q.25 Which ONE of the following statements is CORRECT?

(A) The major components of biodiesel are triglycerides

(B) Biodiesel is essentially a mixture of ethyl esters

(C) Biodiesel is highly aromatic

(D) Biodiesel has a very low aniline point

Q. 26 – Q. 55 carry two marks each.

Q.26 Consider the following differential equation

ln( ) ; 2 at 0dy

x y y xdx

= + = =

The solution of this equation at 0.4x = using Euler method with a step size of 0.2h =

is___________

Q.27 The integrating factor for the differential equation

(1 )1

dy yx

dx x− = +

+ is

(A) 1

1 x+ (B) (1 )x+ (C) (1 )x x+ (D)

1

x

x+

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Q.28 The differential equation

22 3

2

xd y dyx x y e

dx dx+ + = is a

(A) non-linear differential equation of first degree

(B) linear differential equation of first degree

(C) linear differential equation of second degree

(D) non-linear differential equation of second degree

Q.29 Consider the following two normal distributions

2

1( ) exp( )f x xπ= −

2

2

1 1( ) exp ( 2 1)

2 4f x x x

π π = − + +

If µ and σ denote the mean and standard deviation, respectively, then

(A) 1 2µ µ< and 2 2

1 2σ σ< (B) 1 2µ µ< and 2 2

1 2σ σ>

(C) 1 2µ µ> and 2 2

1 2σ σ< (D) 1 2µ µ> and 2 2

1 2σ σ>

Q.30 In rolling of two fair dice, the outcome of an experiment is considered to be the sum of the numbers

appearing on the dice. The probability is highest for the outcome of ____________

Q.31 A spherical ball of benzoic acid (diameter = 1.5 cm) is submerged in a pool of still water. The

solubility and diffusivity of benzoic acid in water are 0.03 kmol/m3 and 1.25 x 10

-9 m

2/s

respectively. Sherwood number is given as Sh = 2.0 + 0.6 Re0.5

Sc0.33

. The initial rate of dissolution

(in kmol/s) of benzoic acid approximately is

(A) 3.54×10-11

(B) 3.54×10-12

(C) 3.54×10-13

(D) 3.54×10-14

Q.32 A wet solid of 100 kg is dried from a moisture content of 40 wt% to 10 wt%. The critical moisture

content is 15 wt% and the equilibrium moisture content is negligible. All moisture contents are on

dry basis. The falling rate is considered to be linear. It takes 5 hours to dry the material in the

constant rate period. The duration (in hours) of the falling rate period is ___________

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Q.33 A brick wall of 20 cm thickness has thermal conductivity of 0.7 W m-1

K-1

. An insulation of

thermal conductivity 0.2 W m-1

K-1

is to be applied on one side of the wall, so that the heat transfer

through the wall is reduced by 75%. The same temperature difference is maintained across the wall

before and after applying the insulation. The required thickness (in cm) of the insulation is

____________

Q.34 An oil with a flow rate of 1000 kg/h is to be cooled using water in a double-pipe counter-flow heat

exchanger from a temperature of 70 °C to 40 °C. Water enters the exchanger at 25 °C and leaves at

40 °C. The specific heats of oil and water are 2 kJ kg-1

K-1

and 4.2 kJ kg-1

K-1

, respectively. The

overall heat transfer coefficient is 0.2 kW m-2

K-1

. The minimum heat exchanger area (in m2)

required for this operation is ______________

Q.35 Which ONE of the following is CORRECT for an ideal gas in a closed system?

(A) S V

U UV nR

V S

∂ ∂ = ∂ ∂ (B)

S P

H HP nR

P S

∂ ∂ − = ∂ ∂

(C) S P

U HV nR

V S

∂ ∂ = ∂ ∂ (D)

S V

H UP nR

P S

∂ ∂ = ∂ ∂

Q.36 A binary distillation column is operating with a mixed feed containing 20 mol% vapour. If the feed

quality is changed to 80 mol% vapour, the change in the slope of the q-line is ________________

Q.37 A homogeneous reaction ( )R P→ occurs in a batch reactor. The conversion of the reactant R is

67% after 10 minutes and 80% after 20 minutes. The rate equation for this reaction is

(A) Rr k− = (B)

2

R Rr k C− =

(C)

3

R Rr k C− = (D)

0.5

R Rr k C− =

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Q.38 A vapour phase catalytic reaction ( )Q R S+ → follows Rideal mechanism (R and S are not

adsorbed). Initially, the mixture contains only the reactants in equimolar ratio. The surface reaction

step is rate controlling. With constants a and b, the initial rate of reaction ( )or− in terms of total

pressure ( )TP is given by

(A) 1

To

T

aPr

bP− =

+ (B)

21

To

T

aPr

bP− =

+

(C)

2

1

To

T

aPr

bP− =

+ (D)

2

2(1 )

To

T

aPr

bP− =

+

Q.39 An incompressible fluid is flowing through a contraction section of length L and has a 1-D (x-

direction) steady state velocity distribution, 0

21

xu u

L

= +

. If u0 = 2 m/s and L = 3 m, the

convective acceleration (in m/s2) of the fluid at L is _____________


Group 1 Group 2

P. Tank in series model I. Non-isothermal reaction

Q. Liquid-liquid extraction II. Mixer-settler

R. Optimum temperature progression III. PFR with axial mixing

S. Thiele modulus IV. Solid catalyzed reaction

(A) P─II, Q─IV, R─I, S─III (B) P─I, Q─II, R─III, S─IV

(C) P─III, Q─I, R─II, S─IV (D) P─III, Q─II, R─I, S─IV

Q.41 Two elemental gases (A and B) are reacting to form a liquid (C) in a steady state process as per the

reaction A B C+ → . The single-pass conversion of the reaction is only 20% and hence recycle is

used. The product is separated completely in pure form. The fresh feed has 49 mol% of A and B

each along with 2 mol% impurities. The maximum allowable impurities in the recycle stream is 20

mol%. The amount of purge stream (in moles) per 100 moles of the fresh feed is ___________

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Q.42 Carbon monoxide (CO) is burnt in presence of 200% excess pure oxygen and the flame temperature

achieved is 2298 K. The inlet streams are at 25 °C. The standard heat of formation (at 25 °C) of CO

and CO2 are ─110 kJ mol-1

and ─390 kJ mol-1

, respectively. The heat capacities (in J mol-1

K-1

) of

the components are

2

2

3

3

25 14 10

25 42 10

O

CO

p

p

C T

C T

−

−

= + ×

= + ×

where, T is the temperature in K. The heat loss (in kJ) per mole of CO burnt is_____________

Q.43 A cash flow of Rs. 12,000 per year is received at the end of each year (uniform periodic payment)

for 7 consecutive years. The rate of interest is 9% per year compounded annually. The present

worth (in Rs.) of such cash flow at time zero is __________

Q.44 A polymer plant with a production capacity of 10,000 tons per year has an overall yield of 70%, on

mass basis (kg of product per kg of raw material). The raw material costs Rs. 50,000 per ton. A

process modification is proposed to increase the overall yield to 75% with an investment of Rs. 12.5

crore. In how many years can the invested amount be recovered with the additional profit?

___________

Q.45 A step change of magnitude 2 is introduced into a system having the following transfer function

2

2( )

2 4G s

s s=

+ +

The percent overshoot is ____________

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Q.46 Given below is a simplified block diagram of a feedforward control system.

The transfer function of the process is 5

1pG

s=

+and the disturbance transfer function is

2

1

2 1dG

s s=

+ +. The transfer function of the PERFECT feedforward controller, ( )fG s is

(A) 3

5

( 1)s

−+

(B) 5

( 1)s

−+

(C) 1

5( 1)s

−+

(D) 5( 1)s− +

Q.47 The bottom face of a horizontal slab of thickness 6 mm is maintained at 300

°C. The top face is

exposed to a flowing gas at 30 °C. The thermal conductivity of the slab is 1.5 W m

-1 K

-1 and the

convective heat transfer coefficient is 30 W m-2

K-1

. At steady state, the temperature (in °C) of the

top face is __________

Q.48 In a steady incompressible flow, the velocity distribution is given by ˆˆ ˆ3 5V xi Pyj zk= − +

, where,

V is in m/s and x, y, and z are in m. In order to satisfy the mass conservation, the value of the

constant P (in s-1

) is __________


Group 1 Group 2

P. Turbulence I. Reciprocating pump

Q. NPSH II. Packed bed

R. Ergun equation III. Fluctuating velocity

S. Rotameter IV. Impeller

T. Power number V. Vena contracta

(A) P─III, R─II, T─IV (B) Q─V, R─II, S─III

(C) P─III, R─IV, T─II (D) Q─III, S─V, T─IV

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Q.50 In a steady and incompressible flow of a fluid (density = 1.25 kg m-3

), the difference between

stagnation and static pressures at the same location in the flow is 30 mm of mercury (density =

13600 kg m-3

). Considering gravitational acceleration as 10 m s-2

, the fluid speed (in m s-1

) is

______________

Q.51 Consider a binary liquid mixture at equilibrium with its vapour at 25 °C.

Antoine equation for this system is given as 10log sat

i

Bp A

t C= −

+ where t is in °C and p in Torr.

The Antoine constants (A, B, and C) for the system are given in the following table.

Component A B C

1 7.0 1210 230

2 6.5 1206 223

The vapour phase is assumed to be ideal and the activity coefficients (iγ ) for the non-ideal liquid

phase are given by 2

1 2 1

2

2 1 2

ln( ) [2 0.6 ]

ln( ) [1.7 0.6 ]

x x

x x

γ

γ

= −

= +

If the mole fraction of component 1 in liquid phase (x1) is 0.11, then the mole fraction of

component 1 in vapour phase (y1) is ___________

Q.52

A process with transfer function, 2

1pG

s=

− is to be controlled by a feedback proportional

controller with a gain Kc. If the transfer functions of all other elements in the control loop are unity,

then which ONE of the following conditions produces a stable closed loop response?

(A) 0.25cK = (B) 0 0.25cK< < (C) 0.25 0.5cK< < (D) 0.5cK >

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Q.53 Consider the following block diagram for a closed-loop feedback control system

A proportional controller is being used with 4cK = − . If a step change in disturbance of

magnitude 2 affects the system, then the value of the offset is ____________

Q.54 Determine the correctness or otherwise of the following Assertion [a] and Reason [r].

Assertion: Significant combustion of coke takes place only if it is heated at higher temperature in

presence of air.

Reason: 2 2C + O CO→ is an exothermic reaction.

(A) Both [a] and [r] are true and [r] is the correct reason for [a]

(B) Both [a] and [r] are true but [r] is not the correct reason for [a]

(C) [a] is correct but [r] is false

(D) Both [a] and [r] are false

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Q.55 Match the raw materials of Groups 1 and 2 with the final products of Group 3

Group 1 Group 2 Group 3

P1: Ethylene Q1: Ammonia R1: Synthetic fibre

P2: Propylene Q2: 1-Butene R2: Nylon 66

P3: Adipic acid Q3: Ethylene glycol R3: LLDPE

P4: Terephthalic acid Q4: Hexamethylene diamine R4: Acrylonitrile

(A) P1+Q2→R3; P2+Q1→R4; P3+Q4→R2; P4+Q3→R1

(B) P1+Q1→R3; P2+Q3→R1; P3+Q4→R4; P4+Q2→R2

(C) P1+Q2→R2; P2+Q3→R1; P3+Q4→R3; P4+Q1→R4

(D) P1+Q1→R4; P2+Q2→R3; P3+Q4→R2; P4+Q3→R1


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GATE 2014 - Answer KeysGeneral Aptitude– GA

Q. No. Key / Range Q. No. Key / Range Q. No. Key / Range1 A 5 1300 to 1300 9 D2 B 6 D 10 B3 D 7 B4 C 8 180 to 180


Q. No. Key / Range Q. No. Key / Range Q. No. Key / Range1 A 20 B 39 7.99 to 8.012 D 21 D 40 D3 C 22 C 41 9.99 to 10.014 A 23 D 42 32.0 to 38.05 B 24 B 43 60000 to

610006 D 25 B 44 2.55 to 2.707 C 26 2.3 to 2.4 45 16.0 to 16.88 A 27 A 46 C9 C 28 B 47 268 to 27410 D 29 C 48 7.99 to 8.0111 A 30 6.99 to 7.01 49 A12 C 31 B 50 79 to 8213 D 32 1.1 to 1.3 51 0.65 to 0.7514 C 33 17.0 to 17.03 52 D15 D 34 3.75 to 3.95 53 0.49 to 0.5116 C 35 D 54 B17 A 36 3.6 to 3.9 55 A18 B 37 B19 A 38 C


__________________________________________________________

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Paper specific instructions:

1. There are a total of 65 questions carrying 100 marks.Questions are of multiple choice type or

numerical answer type. A multiple choice type question will have four choices for the answer with

only one correct choice. For numerical answer type questions, the answer is a number and no choices will be given. A number as the answer should be entered using the virtual keyboard on the monitor.

2. Questions Q.1 – Q.25 carry 1mark each. Questions Q.26 – Q.55 carry 2marks each. The 2marks questions include two pairs of common data questions and two pairs of linked answer questions. The

answer to the second question of the linked answer questions depends on the answer to the first

question of the pair. If the first question in the linked pair is wrongly answered or is not attempted, then the answer to the second question in the pair will not be evaluated.

3. Questions Q.56 – Q.65 belong to General Aptitude (GA) section and carry a total of 15 marks.

Questions Q.56 – Q.60 carry 1mark each, and questions Q.61 – Q.65 carry 2marks each.

4. Questions not attempted will result in zero mark. Wrong answers for multiple choice type questions

will result in NEGATIVE marks. For all 1 mark questions, ⅓ mark will be deducted for each wrong

answer. For all 2 marks questions, ⅔ mark will be deducted for each wrong answer. However, in the

case of the linked answer question pair, there will be negative marks only for wrong answer to the first question and no negative marks for wrong answer to the second question. There is no negative

marking for questions of numerical answer type.

5. Calculator is allowed. Charts, graph sheets or tables are NOT allowed in the examination hall.

6. Do the rough work in the Scribble Pad provided.

Duration: Three Hours Maximum Marks:100


GATE 2013 Chemical Engg. - CH

GATE 2013 Solved PaperChemical Engineering - CH

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Q.1 The number of emails received on six consecutive days is 11, 9, 18, 18, 4 and 15, respectively.

What are the median and the mode for these data?

(A) 18 and 11, respectively

(B) 13 and 18, respectively

(C) 13 and 12.5, respectively (D) 12.5 and 18, respectively

Q.2 For two rolls of a fair die, the probability of getting a 4 in the first roll and a number less than 4 in

the second roll, up to 3 digits after the decimal point, is _________

Q.3 Which of the following statements are TRUE?

P. The eigenvalues of a symmetric matrix are real Q. The value of the determinant of an orthogonal matrix can only be +1

R. The transpose of a square matrix A has the same eigenvalues as those of A

S. The inverse of an ‘n × n’ matrix exists if and only if the rank is less than ‘n’

(A) P and Q only (B) P and R only (C) Q and R only (D) P and S only

Q.4 Evaluate

1x

dx

e

( Note: C is a constant of integration.)

(A) 1

x

x

eC

e (B)

ln 1

x

x

eC

e

(C) ln1

x

x

eC

e (D) ln 1

xe C

Q.5 A gaseous system contains H2, I2, and HI, which participate in the gas-phase reaction

2 22 HI H + I

At a state of reaction equilibrium, the number of thermodynamic degrees of freedom is _________

Q.6 The thermodynamic state of a closed system containing a pure fluid changes from (T1, p1) to

(T2, p2), where T and p denote the temperature and pressure, respectively. Let Q denote the heat absorbed (> 0 if absorbed by the system) and W the work done (> 0 if done by the system). Neglect

changes in kinetic and potential energies. Which one of the following is CORRECT?

(A)Q is path-independent and W is path-dependent

(B)Q is path-dependent and W is path-independent

(C) (Q − W) is path-independent

(D) (Q + W) is path-independent



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Q.7 An equation of state is explicit in pressure p and cubic in the specific volume v. At the critical point

‘c’, the isotherm passing through ‘c’ satisfies

(A)

2

20, 0

p p

v v

(B)

2

20, 0

p p

v v

(C)

2

20, 0

p p

v v

(D)

2

20, 0

p p

v v

Q.8 The units of the isothermal compressibility are

(A) m-3

(B) Pa-1

(C) m3 Pa

-1 (D) m

-3 Pa

-1

Q.9 An open tank contains two immiscible liquids of densities (800 kg/m3 and 1000 kg/m

3) as shown in

the figure. If g = 10 m/s2, under static conditions, the gauge pressure at the bottom of the tank in Pa

is ___________

Q.10 The apparent viscosity of a fluid is given by

0.3

0.007dV

dywhere

dV

dy

is the velocity gradient. The fluid is

(A) Bingham plastic (B) dilatant (C) pseudoplastic (D) thixotropic

Q.11 The mass balance for a fluid with density (and velocity vector V

is

(A)

0Vt

(B)

0Vt

(C)

0Vt

(D)

0Vt



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Q.12 An incompressible Newtonian fluid, filled in an annular gap between two concentric cylinders of

radii R1 and R2 as shown in the figure, is flowing under steady state conditions. The outer cylinder

is rotating with an angular velocity of while the inner cylinder is stationary. Given that

2 1 1R R R , the profile of the -component of the velocity V can be approximated by,

(A) 2R (B)

2

2 1

r R

rR R

(C)

1

1

2 1

r RR

R R

(D)

1

2

2 1

r RR

R R

Q.13 For a Newtonian fluid flowing in a circular pipe under steady state conditions in fully developed

laminar flow, the Fanning friction factor is

(A)

0.20.046Re

(B)

0.32

0.1250.0014

Re

(C)

16

Re (D)

24

Re

Q.14 In the Tyler standard screen scale series, when the mesh number increases from 3 mesh to 10 mesh,

then

(A) the clear opening decreases

(B) the clear opening increases

(C) the clear opening is unchanged

(D) the wire diameter increases

Q.15 Taking the acceleration due to gravity to be 10 m/s

2, the separation factor of a cyclone 0.5 m in

diameter and having a tangential velocity of 20 m/s near the wall is _________

R1

R2

r

W

R1

≤ r ≤ R2



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Q.16 The effectiveness of a heat exchanger in the -NTU method is defined as

(A) increase in temperature of the cold fluid

decrease in temperature of the hot fluid

(B) actual exit temperature attained by the cold fluid

maximum exit temperature attainable by the cold fluid

(C) actual exit temperature attained by the hot fluid

minimum exit temperature attainable by the hot fluid

(D) actual heat transfer rate

maximum possible heat transfer rate from hot fluid to cold fluid

Q.17 In a pool boiling experiment, the following phenomena were observed.

P. Natural convection Q. Film boiling

R. Transition boiling

S. Nucleate boiling

What was the CORRECT sequence of their occurrence?

(A) P, Q, R, S (B) S, R, Q, P (C) Q, R, P, S (D) P, S, R, Q

Q.18 A hole of area 1 cm2 is opened on the surface of a large spherical cavity whose inside temperature

is maintained at 727 °C. The value of Stefan-Boltzmann constant is 5.67×10-8

W/m2-K

4.

Assuming black body radiation, the rate at which the energy is emitted (in W) by the cavity through the hole, up to 3 digits after the decimal point, is ________

Q.19 The packing of an existing absorption tower is replaced with a new type of packing. The height of

the packing and the inlet conditions are maintained the same as before. Tests reveal that the

number of transfer units is lower than before. This indicates that the tower with the new packing,

when compared to that with the old packing, will

(A) have a higher rate of absorption of the solute from the gas stream

(B) have a lower rate of absorption of the solute from the gas stream

(C) have the same rate of absorption of the solute from the gas stream

(D) have a lower height of transfer unit

Q.20 A wet solid is dried over a long period of time by unsaturated air of nonzero constant relative humidity. The moisture content eventually attained by the solid is termed as the

(A) unbound moisture content

(B) bound moisture content

(C) free moisture content

(D) equilibrium moisture content



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Q.21 The exit age distribution for a reactor is given by E(t) = (t - 4), where t is in seconds. A first order liquid phase reaction (k = 0.25 s

-1) is carried out in this reactor under steady state and isothermal

conditions. The mean conversion of the reactant at the exit of the reactor, up to 2 digits after the decimal point, is __________

Q.22 An isothermal liquid phase zero order reaction A B (k = 0.5 mol/m

3-s) is carried out in a batch

reactor. The initial concentration of A is 2 mol/m3. At 3 seconds from the start of the reaction, the

concentration of A in mol/m3 is __________

Q.23 The overall rates of an isothermal catalytic reaction using spherical catalyst particles of diameters

1 mm and 2 mm are rA1 and rA2 (in mol (kg-catalyst)-1

h-1

), respectively. The other physical properties of the catalyst particles are identical. If pore diffusion resistance is very high, the ratio

rA2/rA1 is __________

Q.24 In the manufacture of sulphuric acid by the contact process, the catalytic oxidation of SO2 is carried

out in multiple stages mainly to

(A) increase the reaction rate by providing inter-stage heating

(B) increase the overall conversion by providing inter-stage heating

(C) increase the overall conversion by providing inter-stage cooling

(D) decrease the overall conversion by removing sulphur trioxide between stages

Q.25 Match the following.

Group 1 Group 2 (P) Viscosity (1) Pyrometer (Q) Pressure (2) Hot wire anemometer

(R) Velocity (3) Rheometer

(S) Temperature (4) Piezoelectric element

(A) P-4, Q-3, R-1, S-2

(B) P-3, Q-4, R-2, S-1

(C) P-3, Q-4, R-1, S-2 (D) P-4, Q-3, R-2, S-1

Q. 26 to Q. 55 carry two marks each.

Q.26 For the function

1

2 2f z

z z

the residue at z = 2 is _________



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Q.27 The solution of the differential equation

2 0dy

ydx

, given 1y at 0x is

(A) 1

1 x (B)

1

1 x (C)

2

1

1 x (D)

3

13

x

Q.28 The solution of the differential equation

2

20.25 0

d y dyy

dx dx , given 0 at 0y x and 1 at 0

dyx

dx is

(A)

0.5 0.5x xx e x e

(B) 0.5 0.5x xx e xe

(C)

0.5xx e (D)

0.5xx e

Q.29 The value of the integral

∫ .

.

evaluated by Simpson’s rule using 4 subintervals (up to 3 digits after the decimal point) is ____

Q.30 In a process occurring in a closed system F, the heat transferred from F to the surroundings E is 600 J. If the temperature of E is 300 K and that of F is in the range 380 - 400 K, the entropy

changes of the surroundings (ΔSE) and system (ΔSF), in J/K, are given by

(A) ΔSE = 2, ΔSF = -2

(B) ΔSE = -2, ΔSF = 2

(C) ΔSE = 2, ΔSF < -2 (D) ΔSE = 2, ΔSF > -2

Q.31 A binary liquid mixture is in equilibrium with its vapor at a temperature T = 300 K. The liquid

mole fraction x1 of species 1 is 0.4 and the molar excess Gibbs free energy is 200 J/mol. The value

of the universal gas constant is 8.314 J/mol-K, and i denotes the liquid-phase activity coefficient of

species i. If ln(1) = 0.09, then the value of ln(2), up to 2 digits after the decimal point, is ________



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Q.32 Water (density 1000 kg/m3) is flowing through a nozzle, as shown below and exiting to the

atmosphere. The relationship between the diameters of the nozzle at locations 1 and 2 is D1 = 4 D2. The average velocity of the stream at location 2 is 16 m/s and the frictional loss between location 1

and location 2 is 10000 Pa. Assuming steady state and turbulent flow, the gauge pressure in Pa, at

location 1 is ___________

Q.33 In the elutriation leg of a commercial crystallizer containing a mixture of coarse and very fine crystals of the same material, a liquid is pumped vertically upward. The liquid velocity is adjusted

such that it is slightly lower than the terminal velocity of the coarse crystals only. Hence

(A) the very fine and coarse crystals will both be carried upward by the liquid

(B) the very fine and coarse crystals will both settle at the bottom of the tube

(C) the very fine crystals will be carried upward and the coarse crystals will settle

(D) the coarse crystals will be carried upward and the very fine crystals will settle

Q.34 100 ton/h of a rock feed, of which 80% passed through a mesh size of 2.54 mm, were reduced in

size such that 80% of the crushed product passed through a mesh size of 1.27 mm. The power

consumption was 100 kW. If 100 ton/h of the same material is similarly crushed from a mesh size

of 5.08 mm to a mesh size of 2.54 mm, the power consumption (in kW, to the nearest integer) using

Bond’s law, is _____________

Q.35 Calculate the heat required (in kJ, up to 1 digit after the decimal point) to raise the temperature of

1 mole of a solid material from 100 °C to 1000 °C. The specific heat (Cp) of the material (in J/mol-K) is expressed as Cp = 20 + 0.005T, where T is in K. Assume no phase change. _________

Q.36 In a double pipe counter-current heat exchanger, the temperature profiles shown in the figure were

observed. During operation, due to fouling inside the pipe, the heat transfer rate reduces to half of

the original value. Assuming that the flow rates and the physical properties of the fluids do not

change, the LMTD (in °C) in the new situation is

(A) 0 (B) 20 (C) 40 (D) indeterminate



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Q.37 The vapor-liquid equilibrium curve of a binary mixture A-B, may be approximated by a linear

equation over a narrow range of liquid mole fractions ( 0.2 < Ax < 0.3) as follows

* 1.325 0.121A Ay x

Here*Ay is the mole fraction of A in the vapor. 100 moles of a feed ( ,A Fx = 0.28) is batch distilled

to a final residue ( ,A Wx = 0.2). Using the Rayleigh equation, the number of moles of the residue

left behind in the distillation unit, up to 2 digits after the decimal point, is ____________

Q.38 A crosscurrent cascade of N ideal stages is used to treat a feed stream of molar flow rate E. The

feed stream contains a solute which is to be recovered by a pure solvent having a molar flow rate S.

The solvent is divided equally between these N stages. The linear equilibrium curve relating the

mole fractions x and y* of the solute in the raffinate and the extract respectively, is given by

y* = m x. Assume dilute conditions. The ratio of the solute mole fraction in the original feed to

that in the exit raffinate stream i.e. 0 Nx / x is given by

(A) 1

NmS

NE

(B) 1

NNS

mE

(C) 1

NNE

mS

(D) 1

NmE

NS

Q.39 A study was conducted in which water was pumped through cylindrical pipes made of a sparingly soluble solid. For a given pipe and certain flow conditions, the mass transfer coefficient kc has been

calculated as 1 mm/s using the correlation

Sh = 0.025 Re 0.6

Sc 0.33

If the velocity of the fluid and the diameter of the pipe are both doubled, what is the new value of kc

in mm/s, up to 2 digits after the decimal point? ____________



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Q.40 The gas phase decomposition of azomethane to give ethane and nitrogen takes place according to

the following sequence of elementary reactions.

(CH3)2N2 + (CH3)2N2 → (CH3)2N2 + [(CH3)2N2]*

[(CH3)2N2]* + (CH3)2N2 → (CH3)2N2 + (CH3)2N2

[(CH3)2N2]* → C2H6 + N2

Using the pseudo-steady-state-approximation for [(CH3)2N2]*, the order with respect to azomethane

in the rate expression for the formation of ethane, in the limit of high concentrations of azomethane,

is ___________

Q.41 A first order liquid phase reaction is carried out isothermally at a steady state in a CSTR and 90%

conversion is attained. With the same inlet conditions and for the same overall conversion, if the CSTR is replaced by two smaller and identical isothermal CSTRs in series, the % reduction in total

volume, to the nearest integer, is ____________

Q.42 Match the reactant-product combination in Group 1 with the unit process in Group 2.

Group 1 Group 2 (P) propylene - butanol (1) Pyrolysis

(Q) cumene - phenol (2) Dehydrogenation

(R) butane - butadiene (3) Hydroformylation (S) ethylene dichloride - vinyl chloride (4) Peroxidation

(A) P-3, Q-2, R-4, S-1

(B) P-2, Q-4, R-3, S-1

(C) P-1, Q-3, R-2, S-4 (D) P-3, Q-4, R-2, S-1

Q.43 Identify which of the following statements are FALSE.

(P) Oils with an oleic radical (1 double bond) are more suitable than oils with a linolenic radical (3 double bonds) as film forming vehicles for paints

(Q) Production of synthesis gas from coal and steam is an endothermic process

(R) Use of chlorine for bleaching of wood pulp results in the release of dioxins (S) In the manufacture of urea from ammonia, the main intermediate product formed is ammonium

bicarbonate

(A) P and Q only

(B) R and S only

(C)QandRonly (D) P and S only

Q.44 A unit gain 2nd

order underdamped process has a period of oscillation 1 second and decay ratio

0.25. The transfer function of the process is

(A) 2

1

0.024 0.067 1s s (B)

2

1

0.067 0.024 1s s

(C) 2

1

0.021 0.1176 1s s (D)

2

1

0.1176 0.021 1s s



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Q.45 A control valve, with a turndown ratio of 50, follows equal percentage characteristics. The flow rate of a liquid through the valve at 40% stem position is 1 m

3/h. What will be the flow rate in m

3/h at

50% stem position, if the pressure drop across the valve remains unchanged? (Up to 2 digits after

the decimal point.) ________

Q.46 The purchase cost of a heat exchanger of 20 m2 area was Rs. 500000 in 2006. What will be the

estimated cost (in Rs. to the nearest integer) of a similar heat exchanger of 50 m2 area in the year

2013? Assume the six-tenths factor rule for scaling and the cost index for 2006 as 430.2. The projected cost index for the year 2013 is 512.6. _________

Q.47 A plant manufactures compressors at the rate of N units/day. The daily fixed charges are Rs. 20000

and the variable cost per compressor is Rs. 500 + 0.2 N1.3

. The selling price per compressor is

Rs. 1000. The number of compressors to be manufactured, to the nearest integer, in order to

maximize the daily profit is ___________

Common Data Questions

Common Data for Questions 48 and 49:

A reverse osmosis unit treats feed water (F) containing fluoride and its output consists of a permeate stream (P) and a reject stream (R). Let CF, CP, and CR denote the fluoride concentrations in the feed, permeate, and

reject streams, respectively. Under steady state conditions, the volumetric flow rate of the reject is 60 % of

the volumetric flow rate of the inlet stream, and CF = 2 mg/L and CP = 0.1 mg/L.

Q.48 The value of CR in mg/L, up to one digit after the decimal point, is _________

Q.49 A fraction f of the feed is bypassed and mixed with the permeate to obtain treated water having a

fluoride concentration of 1 mg/L. Here also the flow rate of the reject stream is 60% of the flow rate

entering the reverse osmosis unit (after the bypass). The value of f , up to 2 digits after the decimal point, is __________


Liquid reactant A decomposes as follows

A R 2

1R Ar k C k1 = 0.5 m3/mol-s

A S 2S Ar k C k2 = 1 s-1

An aqueous feed of composition CA0 = 30 mol/m3, CR0 = 2 mol/m

3, and CS0= 1 mol/m

3 enters a CSTR in

which the above reactions occur. Assume isothermal and steady state conditions.

Q.50 If the conversion of A is 80 %, the concentration of R in the exit stream in mol/m3, to the nearest

integer, is _________



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Q.51 What is the % conversion of A, to the nearest integer, so that the concentration of S in the exit stream is 11.8 mol/m

3? _________

Linked Answer Questions

Statement for Linked Answer Questions 52 and 53:

The vapor liquid equilibrium relation for an ideal binary system is given by

∗ = 1 + ( − 1)

Here and ∗ are the mole fractions of species A in the liquid and vapor, respectively. The relative

volatility ( ) is greater than unity.

Q.52 The liquid mole fraction at which the maximum difference between the equilibrium vapor mole

fraction and liquid mole fraction occurs is

(A) ( )

(B) .

( )

(C) .

( )

(D) .

( )

Q.53 A liquid having the composition found in the first part of the linked answer question, is flash

distilled at a steady state to a final liquid mole fraction of 0.25. If is 2.5, the fraction of the

feed vaporized is

(A) 0.08

(B) 0.20 (C) 0.67 (D) 0.74


Consider the following transfer function

4

5

2 1pG s

s

(Note: The unit of the process time constant is in seconds.)

Q.54 The crossover frequency (in rad/s) of the process is

(A) 20 (B) 0.1 (C) 0.5 (D) 0.05

Q.55 For the computation of Ziegler-Nichols settings, the ultimate period (in s/cycle) and the ultimate

gain are

(A) and 0.8, respectively

(B) 4 and 0.8, respectively

(C) 4 and 1.25, respectively (D) and 1.25, respectively



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Q.56 If 3 ≤ ≤ 5 and 8 ≤ ≤ 11 then which of the following options is TRUE?

(A) ≤ ≤

(B) ≤ ≤

(C) ≤ ≤

(D) ≤ ≤

Q.57 The Headmaster ___________ to speak to you.

Which of the following options is incorrect to complete the above sentence?

(A) is wanting

(B) wants

(C) want

(D) was wanting

Q.58 Mahatama Gandhi was known for his humility as

(A) he played an important role in humiliating exit of British from India.

(B) he worked for humanitarian causes.

(C) he displayed modesty in his interactions.

(D) he was a fine human being.

Q.59 All engineering students should learn mechanics, mathematics and how to do computation.

I II III IV

Which of the above underlined parts of the sentence is not appropriate?

(A) I (B) II (C) III (D) IV

Q.60 Select the pair that best expresses a relationship similar to that expressed in the pair:

water: pipe::

(A) cart: road (B) electricity: wire

(C) sea: beach (D) music: instrument


Q.61 Velocity of an object fired directly in upward direction is given by = 80 − 32 , where (time)

is in seconds. When will the velocity be between 32 m/sec and 64 m/sec?

(A) (1, 3/2) (B) (1/2, 1)

(C) (1/2, 3/2) (D) (1, 3)



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Q.62 In a factory, two machines M1 and M2 manufacture 60% and 40% of the autocomponents

respectively. Out of the total production, 2% of M1 and 3% of M2 are found to be defective. If a

randomly drawn autocomponent from the combined lot is found defective, what is the probability

that it was manufactured by M2?

(A) 0.35 (B) 0.45 (C) 0.5 (D) 0.4

Q.63 Following table gives data on tourists from different countries visiting India in the year 2011.

Country Number of

Tourists

USA 2000

England 3500

Germany 1200

Italy 1100

Japan 2400

Australia 2300

France 1000

Which two countries contributed to the one third of the total number of tourists who visited India in 2011?

(A) USA and Japan

(B) USA and Australia

(C) England and France

(D) Japan and Australia

Q.64 If |−2 + 9| = 3 then the possible value of |− | − would be:

(A) 30 (B) -30 (C) -42 (D) 42

Q.65 All professors are researchers

Some scientists are professors

Which of the given conclusions is logically valid and is inferred from the above arguments:

(A) All scientists are researchers

(B) All professors are scientists

(C) Some researchers are scientists

(D) No conclusion follows




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GATE 2013 - Answer KeysChemical Engineering - CH

Q. No Key/Range Q. No Key/Range Q. No Key/Range1 B 23 0.5 45 1.47 to 1.492 0.082 to

0.08424 C 46 1010000 to

10500003 B 25 B 47 215 to 2204 D 26 -0.25 48 3.2 to 3.45 3 27 B 49 0.25 to 0.276 C 28 C 50 207 D 29 0.38 to 0.39 51 908 B 30 D 52 A9 26000 31 0.06 to 0.08 53 C10 B 32 137500 54 C11 A 33 C 55 B12 D 34 69 to 72 56 B13 C 35 21 to 22 57 C14 A 36 C 58 C15 160 37 66 to 67 59 D16 D 38 A 60 B17 D 39 1.14 to 1.16 61 C18 5.6 to 5.8 40 1 62 C19 B 41 51 to 53 63 C20 D 42 D 64 B21 0.62 to 0.64 43 D 65 C22 0.54 44 A


_________________________________________________________

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Duration: Three Hours Maximum Marks: 100

Read the following instructions carefully.

1. Do not open the seal of the Question Booklet until you are asked to do so by the invigilator.

2. Take out the Optical Response Sheet (ORS) from this Question Booklet without breaking the seal

and read the instructions printed on the ORS carefully. 3. On the right half of the ORS, using ONLY a black ink ball point pen, (i) darken the bubble

corresponding to your test paper code and the appropriate bubble under each digit of your registration number and (ii) write your registration number, your name and name of the examination centre and put your signature at the specified location.

4. This Question Booklet contains 20 pages including blank pages for rough work. After you are

permitted to open the seal, please check all pages and report discrepancies, if any, to the invigilator.

5. There are a total of 65 questions carrying 100 marks. All these questions are of objective type. Each question has only one correct answer. Questions must be answered on the left hand side of the ORS by darkening the appropriate bubble (marked A, B, C, D) using ONLY a black ink ball point pen against the question number. For each question darken the bubble of the correct answer. More than one answer bubbled against a question will be treated as an incorrect response.

6. Since bubbles darkened by the black ink ball point pen cannot be erased, candidates should darken

the bubbles in the ORS very carefully.

7. Questions Q.1 – Q.25 carry 1 mark each. Questions Q.26 – Q.55 carry 2 marks each. The 2 marks questions include two pairs of common data questions and two pairs of linked answer questions. The answer to the second question of the linked answer questions depends on the answer to the first question of the pair. If the first question in the linked pair is wrongly answered or is unattempted, then the answer to the second question in the pair will not be evaluated.

8. Questions Q.56 – Q.65 belong to General Aptitude (GA) section and carry a total of 15 marks.

Questions Q.56 – Q.60 carry 1 mark each, and questions Q.61 – Q.65 carry 2 marks each.

9. Unattempted questions will result in zero mark and wrong answers will result in NEGATIVE marks.

For all 1 mark questions, mark will be deducted for each wrong answer. For all 2 marks questions,

mark will be deducted for each wrong answer. However, in the case of the linked answer question pair, there will be negative marks only for wrong answer to the first question and no negative marks for wrong answer to the second question.

10. Calculator is allowed whereas charts, graph sheets or tables are NOT allowed in the examination hall. 11. Rough work can be done on the question paper itself. Blank pages are provided at the end of the

question paper for rough work.

12. Before the start of the examination, write your name and registration number in the space provided below using a black ink ball point pen.

Name

Registration

Number CH



GATE 2012 Solved Paper


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Q.1 Consider the following set of linear algebraic equations

1 2 3

2 3

2 3

2 3 2

1

2 2 0

x x x

x x

x x

The system has

(A) a unique solution (B) no solution

(C) an infinite number of solutions (D) only the trivial solution

Q.2 If a and b are arbitrary constants, then the solution to the ordinary differential equation 2

24 0

d yy

dx

is

(A) y ax b

(B) xy ae

(C) sin 2 cos2y a x b x

(D) cosh 2 sinh 2y a x b x

Q.3 For the function /( ) t

f t e ,

the Taylor series approximation for t is

(A) 1t

(B) 1

t

(C)

2

21

2

t

(D) 1 t

Q.4 A box containing 10 identical compartments has 6 red balls and 2 blue balls. If each compartment

can hold only one ball, then the number of different possible arrangements are

(A) 1026 (B) 1062 (C) 1260 (D) 1620

Q.5 Consider the following 2 2 matrix

4 0

0 4

.

Which one of the following vectors is NOT a valid eigenvector of the above matrix ?

(A) 1

0

(B) 2

1

(C) 4

3

(D) 0

0

Q.6 In a throttling process, the pressure of an ideal gas reduces by 50 %. If PC and VC are the heat

capacities at constant pressure and constant volume, respectively ( P VC C ), the specific

volume will change by a factor of

(A) 2

(B) 12 (C) ( 1)2 (D) 0.5



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Q.7 If the temperature of saturated water is increased infinitesimally at constant entropy, the resulting

state of water will be

(A) Liquid (B) Liquid – vapor coexistence

(C) Saturated vapor (D) Solid

Q.8 In a parallel flow heat exchanger operating under steady state, hot liquid enters at a temperature

,h inT and leaves at a temperature ,h out

T . Cold liquid enters at a temperature ,c inT and leaves at a

temperature ,c outT . Neglect any heat loss from the heat exchanger to the surrounding. If

,h inT >>

,c inT , then for a given time interval, which ONE of the following statements is true?

(A) Entropy gained by the cold stream is GREATER than entropy lost by the hot stream

(B) Entropy gained by the cold stream is EQUAL to the entropy lost by the hot stream

(C) Entropy gained by the cold stream is LESS than the entropy lost by the hot stream

(D) Entropy gained by the cold stream is ZERO

Q.9 For an exothermic reversible reaction, which one of the following correctly describes the

dependence of the equilibrium constant ( K ) with temperature (T ) and pressure ( P ) ?

(A) K is independent of T and P

(B) K increases with an increase in T and P

(C) K increases with T and decreases with P

(D) K decreases with an increase in T and is independent of P

Q.10 Water is flowing under laminar conditions in a pipe of length L . If the diameter of the pipe is

doubled, for a constant volumetric flow rate, the pressure drop across the pipe

(A) decreases 2 times (B) decreases 16 times

(C) increases 2 times (D) increases 16 times

Q.11 The local velocity of a fluid along a streamline can be measured by

(A) Pitot tube (B) Venturi meter (C) Rotameter (D) Orifice meter

Q.12 For uniform laminar flow (in the x -direction) past a flat plate at high Reynolds number, the local

boundary layer thickness ( ) varies with the distance along the plate ( x ) as

(A) 1

4x (B) 1

3x (C) 1

2x (D) x

Q.13 In a mixing tank operating at very high Reynolds number (> 410 ), if the diameter of the impeller is

doubled (other conditions remaining constant), the power required increases by a factor of

(A) 1/32 (B) 1/4 (C) 4 (D) 32

Q.14 For heat transfer across a solid-fluid interface, which one of the following statements is NOT true

when the Biot number is very small compared to 1?

(A) Conduction resistance in the solid is very small compared to convection resistance in the fluid

(B) Temperature profile within the solid is nearly uniform

(C) Temperature drop in the fluid is significant

(D) Temperature drop in the solid is significant



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Q.15 A solid sphere with an initial temperature iT is immersed in a large thermal reservoir of

temperature oT . The sphere reaches a steady temperature after a certain time 1t . If the radius of the

sphere is doubled, the time required to reach steady-state will be

(A) 1t /4 (B)

1t /2 (C) 21t (D) 4

1t

Q.16 If the Nusselt number ( Nu ) for heat transfer in a pipe varies with Reynolds number ( Re ) as

0.8Nu Re , then for constant average velocity in the pipe, the heat transfer coefficient varies with

the pipe diameter D as

(A) 1.8

D

(B) 0.2

D

(C) 0.2

D (D) 1.8

D

Q.17 In the McCabe-Thiele diagram, if the x -coordinate of the point of intersection of the q -line and

the vapor-liquid equilibrium curve is greater than the x -coordinate of the feed point, then the

quality of the feed is

(A) super-heated vapor (B) liquid below bubble point

(C) saturated vapor (D) saturated liquid

Q.18 For which of the following combinations, does the absorption operation become gas-film

controlled?

P. The solubility of gas in the liquid is very high

Q. The solubility of gas in the liquid is very low

R. The liquid-side mass transfer coefficient is much higher than the gas-side mass transfer

coefficient

S. The liquid-side mass transfer coefficient is much lower than the gas-side mass transfer

coefficient

(A) P & Q (B) P & R (C) P & S (D) Q & R

Q.19 The half-life of an n

th order reaction in a batch reactor depends on

(A) only the rate constant

(B) only the rate constant and the order of the reaction

(C) only the rate constant and the initial reactant concentration

(D) the rate constant, initial reactant concentration, and the order of the reaction

Q.20 Consider the reaction scheme shown below

1 2k kA B C .

Both the reactions are first-order. The activation energies for 1k and 2k are 80 and 20 kJ/mol,

respectively. To maximize the yield of B, it is preferable to use

(A) CSTR and high temperature

(B) PFR and high temperature

(C) CSTR and low temperature

(D) PFR and low temperature



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Q.21 In petroleum refining, catalytic reforming is used to convert

(A) Paraffins and naphthenes to aromatics

(B) Paraffins to hydrogen and carbon monoxide

(C) Gas oil to diesel and gasoline

(D) Light olefins to gasoline

Q.22 The final boiling points of gasoline, diesel, atmospheric gas oil (AGO) and lubricating oils vary as

(A) gasoline > diesel > AGO > lubricating oils

(B) lubricating oils > AGO > diesel > gasoline

(C) AGO > lubricating oils > diesel > gasoline

(D) lubricating oils > diesel > AGO > gasoline

Q.23 The main unit processes used for the production of hydrogen from natural gas are steam reforming

(SR), pressure swing adsorption (PSA), low temperature water gas shift reaction (LT WGS) and

high temperature water gas shift reaction (HT WGS). The correct sequence of these in the plant is

(A) SR; LT WGS; HT WGS; PSA

(B) PSA; SR; LT WGS; HT WGS

(C) SR; HT WGS; LT WGS; PSA

(D) PSA; HT WGS; LT WGS; SR

Q.24 A thermometer initially at 100°C is dipped at t = 0 into an oil bath, maintained at 150°C. If the

recorded temperature is 130°C after 1 minute, then the time constant of thermometer (in min) is

(A) 1.98 (B) 1.35 (C) 1.26 (D) 1.09

Q.25 The Bode stability criterion is applicable when

(A) Gain and phase curves decrease continuously with frequency

(B) Gain curve increases and phase curve decreases with frequency

(C) Gain curve and phase curve both increase with frequency

(D) Gain curve decreases and phase curve increases with frequency



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Q.26 The one - dimensional unsteady state heat conduction equation in a hollow cylinder with a constant

heat source q is

1T Tr q

t r r r

If A and B are arbitrary constants, then the steady state solution to the above equation is

(A)

2

( )2

qr AT r B

r

(B)

2

( ) ln4

qrT r A r B

(C) ( ) lnT r A r B

(D)

2

( ) ln4

qrT r A r B

Q.27 If a is a constant, then the value of the integral 2

0

axa xe dx

is

(A) 1/ a (B) a (C) 1 (D) 0

Q.28 The Newton – Raphson method is used to find the roots of the equation

cos πf x x x 0 1x .

If the initial guess for the root is 0.5, then the value of x after the first iteration is

(A) 1.02 (B) 0.62 (C) 0.55 (D) 0.38

Q.29 If 1i , the value of the integral

c

dzzz

iz

1

72

2z ,

using the Cauchy residue theorem is

(A) 2πi (B) 0 (C) 6π (D) 6π

Q.30 An insulated, evacuated container is connected to a supply line of an ideal gas at pressure sP ,

temperature sT and specific volume sv . The container is filled with the gas until the pressure in the

container reaches sP . There is no heat transfer between the supply line to the container, and kinetic

and potential energies are negligible. If PC and VC are the heat capacities at constant pressure and

constant volume, respectively ( P VC C ), then the final temperature of the gas in the container is

(A) sT (B) sT (C) 1 sT (D) 1 sT



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Q.31 Consider a binary liquid mixture at constant temperature T and pressure P . If the enthalpy change

of mixing, 1 25H x x , where

1x and 2x are the mole fraction of species 1 and 2 respectively, and

the entropy change of mixing 1 1 2 2ln lnS R x x x x (with R = 8.314 J/mol.K), then the

minimum value of the Gibbs free energy change of mixing at 300 K occurs when

(A) 1x = 0 (B) 1x = 0.2 (C) 1x = 0.4 (D) 1x = 0.5

Q.32 A bed of spherical glass beads (density 3000 kg/m

3, diameter 1 mm, bed porosity 0.5) is to be

fluidized by a liquid of density 1000 kg/m3 and viscosity 0.1 Pa.s. Assume that the Reynolds

number based on particle diameter is very small compared to one. If g = 10 m/s2, then the

minimum velocity (in m/s) required to fluidize the bed is

(A) 43.33 10 (B)

13.33 10 (C) 3 (D) 30

Q.33 For the enclosure formed between two concentric spheres as shown below ( 2 12R R ), the fraction

of radiation leaving the surface area 2A that strikes itself is

R1

R2Area A1

Area A2

R1

R2Area A1

Area A2

(A) 1/4 (B) 1/2 (C) 21 (D) 3/4

Q.34 Heat is generated at a steady rate of 100 W due to resistance heating in a long wire (length = 5 m,

diameter = 2 mm). This wire is wrapped with an insulation of thickness 1 mm that has a thermal

conductivity of 0.1 W/m.K. The insulated wire is exposed to air at 30°C. The convective heat

transfer between the wire and surrounding air is characterized by a heat transfer coefficient of

10 W/m2.K. The temperature (in °C) at the interface between the wire and the insulation is

(A) 211.2 (B) 242.1 (C) 311.2 (D) 484.2

Q.35 In a counter-flow double pipe heat exchanger, oil ( m = 2 kg/s, PC = 2.1 kJ/kg.°C) is cooled from

90 °C to 40 °C by water ( m = 1 kg/s, PC = 4.2 kJ/kg.°C) which enters the inner tube at 10 °C. The

radius of the inner tube is 3 cm and its length is 5 m. Neglecting the wall resistance, the overall heat

transfer coefficient based on the inner radius, in kW/ m2.K, is

(A) 0.743 (B) 7.43 (C) 74.3 (D) 2475



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Q.36 The rate-controlling step for the solid-catalyzed irreversible reaction

A B C

is known to be the reaction of adsorbed A with adsorbed B to give adsorbed C . If iP is the partial

pressure of component i and iK is the adsorption equilibrium constant of component i , then the

form of the Langmuir-Hinshelwood rate expression will be

(A) rate 1

A B

A A B B C C

P P

K P K P K P

(B) rate 21

A B

A A B B C C

P P

K P K P K P

(C) rate 0.51

A B

A A B B C C

P P

K P K P K P

(D) rate A B

C

P P

P

Q.37 Consider the drying operation shown in the figure below for a solid loading (dry basis) of 50 kg/m

2

with a constant drying rate of 5 kg/m2.h. The falling rate of drying is linear with moisture content.

Dry

ing

Rat

e

Moisture (kg H2O/kg dry solid)

Xe Xc

Xc = 0.1

Xe = 0.005

Dry

ing

Rat

e

Moisture (kg H2O/kg dry solid)

Xe Xc

Xc = 0.1

Xe = 0.005

The drying time (in hrs) required to reduce an initial moisture content of 25% to a final moisture

content of 2% is

(A) 1.55 (B) 1.75 (C) 3.25 (D) 4.55

Q.38 An equimolar mixture of A and B (A being more volatile) is flash distilled continuously at a feed

rate of 100 kmol/h, such that the liquid product contains 40 mol % of A. If the relative volatility

is 6, then the vapor product, in kmol/h, is

(A) 10 (B) 20 (C) 25 (D) 45

Q.39 A thermocouple having a linear relationship between 0

oC and 350

oC shows an emf of zero and

30.5 mV, respectively at these two temperatures. If the cold junction temperature is shifted from

0 oC to 30

oC, then the emf correction (in mV) is

(A) 3.13 (B) 2.92 (C) 2.61 (D) 2.02



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Q.40 The characteristic equation for a system is 3 29 26 12(2 ) 0cs s s K .

Using the Routh test, the value of cK that will keep the system on the verge of instability is

(A) 20.9 (B) 18.4 (C) 17.5 (D) 15.3 Q.41 The elementary reversible exothermic gas-phase reaction

CBA 23

is to be conducted in a non-isothermal, non-adiabatic plug flow reactor. The maximum allowable

reactor temperature is maxT . To minimize the total reactor volume, the variation of reactor

temperature (T ) with axial distance from the inlet ( z ) should be

(A)

(B)

(C)

(D)

Q.42 The block diagram of a system with a proportional controller is shown below

Kc

1

1ps

1

1ms

1

U

CR

Kc

1

1ps

1

1ms

1

U

CR

A unit step input is introduced in the set point. The value of cK to provide a critically damped

response for 0U , 8p

and 1m is

(A) 3.34 (B) 2.58 (C) 1.53 (D) 1.12

T

z

Tmax

T

z

Tmax

T

z

Tmax

T

z

Tmax



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Q.43 A batch reactor produces 51 10 kg of a product per year. The total batch time (in hours) of the

reactor is Bk P , where

BP is the product per batch in kg and 1.0k h kg . The operating cost

of the reactor is Rs. 200/h. The total annual fixed charges are Rs. 340 ×BP and the annual raw

material cost is Rs. 62 10 . The optimum size (in kg) of each batch (adjusted to the nearest

integer) is

(A) 748 (B) 873 (C) 953 (D) 1148

Q.44 Heat integration is planned in a process plant at an investment Rs. 62 10 . This would result in a

net energy savings of 20 GJ per year. If the nominal rate of interest is 15% and the plant life is

3 years, then the breakeven cost of energy, in Rs. per GJ (adjusted to the nearest hundred), is

(A) 33500 (B) 43800 (C) 54200 (D) 65400

Q.45 In a 1-1 pass floating head type shell and tube heat exchanger, the tubes (od = 25 mm; id = 21 mm)

are arranged in a square pitch. The tube pitch is 32 mm. The thermal conductivity of the shell side

fluid is 0.19 W/m.K, and the Nusselt number is 200. The shell-side heat transfer coefficient

(in W/m2.K), rounded off to the nearest integer, is

(A) 1100 (B) 1400 (C) 1800 (D) 2100

Q.46 Match the process in Group I with the catalyst in Group II

Group I P. Fischer-Tropsch synthesis

Q. Formaldehyde from methanol

R. Hydrogenation of vegetable oils

S. Dehydrogenation of ethylbenzene

Group II I. Nickel

II. Fe2O3

III. Silver

IV. Cobalt

(A) P-III, Q-IV, R-I, S-II (B) P-IV, Q-II, R-I, S-III

(C) P-IV, Q-III, R-I, S-II (D) P-III, Q-IV, R-II, S-I

Q.47 Match the polymer in Group I to the polymer characteristic in Group II

Group I

P. Polyethylene

Q. Phenol-formaldehyde polymer

R. Polyisoprene

S. Polyester

Group II

I. Elastomer

II. Fiber

III. Thermoplastic

IV. Thermosetting polymer

(A) P-III, Q-IV, R-I, S-II (B) P-IV, Q-II, R-III, S-I

(C) P-III, Q-II, R-I, S-IV (D) P-IV, Q-III, R-I, S-II



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Common Data Questions


A counter-current extraction column is designed to remove 99% of solute C from a solution of solvent A

and solute C using pure solvent B. The initial concentration of solute in the solution of A + C is 20 wt %,

and the total flow of solution is 1000 kg/h. If the equilibrium relationship is 2Y X , where

Y = mass of C/mass of A and X = mass of C/mass of B.

Q.48 The minimum flow rate of solvent B required (in kg/h) is

(A) 1454 (B) 1584 (C) 1676 (D) 1874

Q.49 If the flow rate of B is 2400 kg/h, then the theoretical number of stages in the column, using

Kremser’s equation (adjusted to the next integer) is

(A) 5 (B) 9 (C) 11 (D) 13


The reaction (liq) (gas) (liq) (gas)A +B C +D , is carried out in a reactor followed by a separator as shown

below

YRB , FRG

Reactor

FFB

Separator

FB

FA

FPG

FC

YRB , FRG

Reactor

FFB

Separator

FB

FA

FPG

FC

Notation:

Molar flow rate of fresh B is FBF

Molar flow rate of A is AF

Molar flow rate of recycle gas is RGF

Mole fraction of B in recycle gas is RBY

Molar flow rate of purge gas is PGF

Molar flow rate of C is CF

Here, FBF = 2 mol/s; AF = 1 mol/s, B AF F = 5 and A is completely converted.

Q.50 If RBY = 0.3, the ratio of recycle gas to purge gas RG PGF F is

(A) 2 (B) 5 (C) 7 (D) 10

Q.51 If the ratio of recycle gas to purge gas RG PGF F is 4 then RBY is

(A) 3/8 (B) 2/5 (C) 1/2 (D) 3/4



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Linked Answer Questions

Statement for Linked Answer Questions 52 and 53: A Newtonian fluid of viscosity flows between two parallel plates due to the motion of the bottom plate

(as shown below), which is moved with a velocity V . The top plate is stationary.

Q.52 The steady, laminar velocity profile in the x -direction is

(A) y

Vb

(B)

2

1y

Vb

(C)

2

1y

Vb

(D) 1y

Vb

Q.53 The force per unit area (in the x -direction) that must be exerted on the bottom plate to maintain the

flow is

(A) V b (B) V b (C) 2 V b (D) 2 V b


The first order liquid phase reaction A P is conducted isothermally in a plug flow reactor of 5 liter

volume. The inlet volumetric flow rate is 1 liter/min and the inlet concentration of A is 2 mole/liter.

Q.54 If the exit concentration of A is 0.5 mole /liter, then the rate constant, in min−1

, is

(A) 0.06 (B) 0.28 (C) 0.42 (D) 0.64

Q.55 The plug flow reactor is replaced by 3 mixed flow reactors in series, each of 2.0 liters volume. The

exact conversion of A (in %) is

(A) 35.9 (B) 52.5 (C) 73.7 (D) 94.8

fluid x

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Q.56 Which one of the following options is the closest in meaning to the word given below?

Mitigate

(A) Diminish (B) Divulge (C) Dedicate (D) Denote

Q.57 Choose the most appropriate alternative from the options given below to complete the following

sentence:

Despite several ––––––––– the mission succeeded in its attempt to resolve the conflict.

(A) attempts (B) setbacks (C) meetings (D) delegations

Q.58 The cost function for a product in a firm is given by 5q2, where q is the amount of production. The

firm can sell the product at a market price of 50 per unit. The number of units to be produced by

the firm such that the profit is maximized is

(A) 5 (B) 10 (C) 15 (D) 25

Q.59 Choose the most appropriate alternative from the options given below to complete the following

sentence:

Suresh’s dog is the one ––––––––– was hurt in the stampede.

(A) that (B) which (C) who (D) whom

Q.60 Choose the grammatically INCORRECT sentence:

(A) They gave us the money back less the service charges of Three Hundred rupees.

(B) This country’s expenditure is not less than that of Bangladesh.

(C) The committee initially asked for a funding of Fifty Lakh rupees, but later settled for a lesser

sum.

(D) This country’s expenditure on educational reforms is very less.

Q. 61 - Q. 65 carry two marks each.

Q.61 An automobile plant contracted to buy shock absorbers from two suppliers X and Y. X supplies

60% and Y supplies 40% of the shock absorbers. All shock absorbers are subjected to a quality test.

The ones that pass the quality test are considered reliable. Of X’s shock absorbers, 96% are reliable.

Of Y’s shock absorbers, 72% are reliable.

The probability that a randomly chosen shock absorber, which is found to be reliable, is made by

Y is

(A) 0.288 (B) 0.334 (C) 0.667 (D) 0.720

Q.62 A political party orders an arch for the entrance to the ground in which the annual convention is

being held. The profile of the arch follows the equation y = 2x – 0.1x2 where y is the height of the

arch in meters. The maximum possible height of the arch is

(A) 8 meters (B) 10 meters (C) 12 meters (D) 14 meters



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Q.63 Wanted Temporary, Part-time persons for the post of Field Interviewer to conduct personal

interviews to collect and collate economic data. Requirements: High School-pass, must be

available for Day, Evening and Saturday work. Transportation paid, expenses reimbursed.

Which one of the following is the best inference from the above advertisement?

(A) Gender-discriminatory

(B) Xenophobic

(C) Not designed to make the post attractive

(D) Not gender-discriminatory

Q.64 Given the sequence of terms, AD CG FK JP, the next term is

(A) OV (B) OW (C) PV (D) PW

Q.65 Which of the following assertions are CORRECT?

P: Adding 7 to each entry in a list adds 7 to the mean of the list

Q: Adding 7 to each entry in a list adds 7 to the standard deviation of the list

R: Doubling each entry in a list doubles the mean of the list

S: Doubling each entry in a list leaves the standard deviation of the list unchanged

(A) P, Q (B) Q, R (C) P, R (D) R, S




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GATE 2012 - Answer KeysChemical Engineering - CH

Q. No. Key / Range Q. No. Key / Range Q. No. Key / Range1 B 23 C 45 B2 D 24 D 46 C3 B 25 A 47 A4 C 26 B 48 B5 D 27 C 49 B6 A 28 D 50 B7 A 29 B 51 A8 A 30 A 52 D9 D 31 D 53 A10 B 32 A 54 B11 A 33 D 55 C12 C 34 A 56 A13 D 35 B 57 B14 D 36 B 58 A15 D 37 C 59 Marks to All16 B 38 C 60 D17 B 39 C 61 B18 B 40 C 62 B19 D 41 C 63 D20 B 42 C 64 A21 A 43 C 65 C22 B 44 B


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GATE Solved Question Papers for Chemical Engineering [CH] by AglaSem.Com