GATE 2021 CE (Set 2)

All 65 questions of GATE 2021 CE (Set 2)

Question text and figures as in the official paper, with the answer from the official key. Worked solutions for every question are in your report after you take the paper as a 3-hour test.

Q1 · General Aptitude · MCQ · 1 mark

(i) Arun and Aparna are here.

(ii) Arun and Aparna is here.

(iii) Arun’s families is here.

(iv) Arun’s family is here.

Which of the above sentences are grammatically CORRECT?

  • (A)
    (i) and (ii)
  • (B)
    (i) and (iv)
  • (C)
    (ii) and (iv)
  • (D)
    (iii) and (iv)

Answer (official key): B

Worked solution: in your report after you take this paper.

Q2 · General Aptitude · MCQ · 1 mark

Figure for GATE 2021 CE (Set 2) question 2 (Spatial Aptitude)

The mirror image of the above text about the x-axis is

  • (A)
    GATE 2021 CE (Set 2) question 2 (Spatial Aptitude), option A
  • (B)
    GATE 2021 CE (Set 2) question 2 (Spatial Aptitude), option B
  • (C)
    GATE 2021 CE (Set 2) question 2 (Spatial Aptitude), option C
  • (D)
    GATE 2021 CE (Set 2) question 2 (Spatial Aptitude), option D

Answer (official key): B

Worked solution: in your report after you take this paper.

Q3 · General Aptitude · MCQ · 1 mark

Two identical cube shaped dice each with faces numbered 1 to 6 are rolled simultaneously. The probability that an even number is rolled out on each dice is:

  • (A)
    136\frac{1}{36}
  • (B)
    112\frac{1}{12}
  • (C)
    18\frac{1}{8}
  • (D)
    14\frac{1}{4}

Answer (official key): D

Read the worked solution

Q4 · General Aptitude · MCQ · 1 mark

⊕\oplus and ⊙\odot are two operators on numbers pp and qq such that p⊙q=p−qp \odot q = p - q, and p⊕q=p×qp \oplus q = p \times q

Then, (9⊙(6⊕7))⊙(7⊕(6⊙5))=\big(9 \odot (6 \oplus 7)\big) \odot \big(7 \oplus (6 \odot 5)\big) =

  • (A)
    40
  • (B)
    -26
  • (C)
    -33
  • (D)
    -40

Answer (official key): D

Worked solution: in your report after you take this paper.

Q5 · General Aptitude · MCQ · 1 mark

Four persons P, Q, R and S are to be seated in a row. R should not be seated at the second position from the left end of the row. The number of distinct seating arrangements possible is:

  • (A)
    6
  • (B)
    9
  • (C)
    18
  • (D)
    24

Answer (official key): C

Read the worked solution

Q6 · General Aptitude · MCQ · 2 marks

On a planar field, you travelled 3 units East from a point O. Next you travelled 4 units South to arrive at point P. Then you travelled from P in the North-East direction such that you arrive at a point that is 6 units East of point O. Next, you travelled in the North-West direction, so that you arrive at point Q that is 8 units North of point P.

The distance of point Q to point O, in the same units, should be _____

  • (A)
    3
  • (B)
    4
  • (C)
    5
  • (D)
    6

Answer (official key): C

Worked solution: in your report after you take this paper.

Q7 · General Aptitude · MCQ · 2 marks

The author said, “Musicians rehearse before their concerts. Actors rehearse their roles before the opening of a new play. On the other hand, I find it strange that many public speakers think they can just walk on to the stage and start speaking. In my opinion, it is no less important for public speakers to rehearse their talks.”

Based on the above passage, which one of the following is TRUE?

  • (A)
    The author is of the opinion that rehearsing is important for musicians, actors and public speakers.
  • (B)
    The author is of the opinion that rehearsing is less important for public speakers than for musicians and actors.
  • (C)
    The author is of the opinion that rehearsing is more important only for musicians than public speakers.
  • (D)
    The author is of the opinion that rehearsal is more important for actors than musicians.

Answer (official key): A

Worked solution: in your report after you take this paper.

Q8 · General Aptitude · MCQ · 2 marks

  1. Some football players play cricket.
  2. All cricket players play hockey.

Among the options given below, the statement that logically follows from the two statements 1 and 2 above, is:

  • (A)
    No football player plays hockey.
  • (B)
    Some football players play hockey.
  • (C)
    All football players play hockey.
  • (D)
    All hockey players play football.

Answer (official key): B

Worked solution: in your report after you take this paper.

Q9 · General Aptitude · MCQ · 2 marks

Figure for GATE 2021 CE (Set 2) question 9 (Quantitative Aptitude)

In the figure shown above, PQRS is a square. The shaded portion is formed by the intersection of sectors of circles with radius equal to the side of the square and centers at S and Q.

The probability that any point picked randomly within the square falls in the shaded area is ______

  • (A)
    4−π24 - \frac{\pi}{2}
  • (B)
    12\frac{1}{2}
  • (C)
    π2−1\frac{\pi}{2} - 1
  • (D)
    π4\frac{\pi}{4}

Answer (official key): C

Worked solution: in your report after you take this paper.

Q10 · General Aptitude · MCQ · 2 marks

In an equilateral triangle PQR, side PQ is divided into four equal parts, side QR is divided into six equal parts and side PR is divided into eight equal parts. The length of each subdivided part in cm is an integer.

The minimum area of the triangle PQR possible, in cm², is

  • (A)
    18
  • (B)
    24
  • (C)
    48348\sqrt{3}
  • (D)
    1443144\sqrt{3}

Answer (official key): D

Worked solution: in your report after you take this paper.

Q11 · Calculus · MCQ · 1 mark

The value of lim⁡x→∞xln⁡(x)1+x2\displaystyle\lim_{x \to \infty} \frac{x \ln(x)}{1 + x^2} is

  • (A)
    0
  • (B)
    1.0
  • (C)
    0.5
  • (D)
    ∞\infty

Answer (official key): A

Worked solution: in your report after you take this paper.

Q12 · Linear Algebra · MCQ · 1 mark

The rank of the matrix [50−500201−50500102]\begin{bmatrix} 5 & 0 & -5 & 0 \\ 0 & 2 & 0 & 1 \\ -5 & 0 & 5 & 0 \\ 0 & 1 & 0 & 2 \end{bmatrix} is

  • (A)
    1
  • (B)
    2
  • (C)
    3
  • (D)
    4

Answer (official key): C

Worked solution: in your report after you take this paper.

Q13 · Calculus · MCQ · 1 mark

The unit normal vector to the surface X2+Y2+Z2−48=0X^2 + Y^2 + Z^2 - 48 = 0 at the point (4, 4, 4) is

  • (A)
    12,12,12\frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}}
  • (B)
    13,13,13\frac{1}{\sqrt{3}}, \frac{1}{\sqrt{3}}, \frac{1}{\sqrt{3}}
  • (C)
    22,22,22\frac{2}{\sqrt{2}}, \frac{2}{\sqrt{2}}, \frac{2}{\sqrt{2}}
  • (D)
    15,15,15\frac{1}{\sqrt{5}}, \frac{1}{\sqrt{5}}, \frac{1}{\sqrt{5}}

Answer (official key): B

Worked solution: in your report after you take this paper.

Q14 · Linear Algebra · MCQ · 1 mark

If AA is a square matrix then orthogonality property mandates

  • (A)
    AAT=IAA^T = I
  • (B)
    AAT=0AA^T = 0
  • (C)
    AAT=A−1AA^T = A^{-1}
  • (D)
    AAT=A2AA^T = A^2

Answer (official key): A

Worked solution: in your report after you take this paper.

Q15 · Geomatics Engineering · MCQ · 1 mark

In general, the CORRECT sequence of surveying operations is

  • (A)
    Field observations → Reconnaissance → Data analysis → Map making
  • (B)
    Data analysis → Reconnaissance → Field observations → Map making
  • (C)
    Reconnaissance → Field observations → Data analysis → Map making
  • (D)
    Reconnaissance → Data analysis → Field observations → Map making

Answer (official key): C

Worked solution: in your report after you take this paper.

Q16 · Structural Engineering · MCQ · 1 mark

Strain hardening of structural steel means

  • (A)
    experiencing higher stress than yield stress with increased deformation
  • (B)
    strengthening steel member externally for reducing strain experienced
  • (C)
    strain occurring before plastic flow of steel material
  • (D)
    decrease in the stress experienced with increasing strain

Answer (official key): A

Worked solution: in your report after you take this paper.

Q17 · Structural Engineering · MCQ · 1 mark

Not in GATE 2027 syllabus: Free vibration of undamped SDOF systems

A single story building model is shown in the figure. The rigid bar of mass ‘mm’ is supported by three massless elastic columns whose ends are fixed against rotation. For each of the columns, the applied lateral force (PP) and corresponding moment (MM) are also shown in the figure. The lateral deflection (δ\delta) of the bar is given by δ=PL312EI\delta = \dfrac{PL^3}{12EI}, where LL is the effective length of the column, EE is the Young’s modulus of elasticity and II is the area moment of inertia of the column cross-section with respect to its neutral axis.

Figure for GATE 2021 CE (Set 2) question 17 (Structural Engineering)

For the lateral deflection profile of the columns as shown in the figure, the natural frequency of the system for horizontal oscillation is

  • (A)
    6EImL36\sqrt{\dfrac{EI}{mL^3}} rad/s
  • (B)
    1L2EIm\dfrac{1}{L}\sqrt{\dfrac{2EI}{m}} rad/s
  • (C)
    26EImL32\sqrt{\dfrac{6EI}{mL^3}} rad/s
  • (D)
    2LEIm\dfrac{2}{L}\sqrt{\dfrac{EI}{m}} rad/s

Answer (official key): A

Worked solution: in your report after you take this paper.

Q18 · Construction Materials and Management · MCQ · 1 mark

Seasoning of timber for use in construction is done essentially to

  • (A)
    increase strength and durability
  • (B)
    smoothen timber surfaces
  • (C)
    remove knots from timber logs
  • (D)
    cut timber in right season and geometry

Answer (official key): A

Worked solution: in your report after you take this paper.

Q19 · Construction Materials and Management · MCQ · 1 mark

In case of bids in Two-Envelop System, the correct option is

  • (A)
    Technical bid is opened first
  • (B)
    Financial bid is opened first
  • (C)
    Both (Technical and Financial) bids are opened simultaneously
  • (D)
    Either of the two (Technical and Financial) bids can be opened first

Answer (official key): A

Worked solution: in your report after you take this paper.

Q20 · Geotechnical Engineering · MCQ · 1 mark

The most appropriate triaxial test to assess the long-term stability of an excavated clay slope is

  • (A)
    consolidated drained test
  • (B)
    unconsolidated undrained test
  • (C)
    consolidated undrained test
  • (D)
    unconfined compression test

Answer (official key): A

Worked solution: in your report after you take this paper.

Q21 · Geotechnical Engineering · MCQ · 1 mark

As per the Unified Soil Classification System (USCS), the type of soil represented by ‘MH’ is

  • (A)
    Inorganic silts of high plasticity with liquid limit more than 50%
  • (B)
    Inorganic silts of low plasticity with liquid limit less than 50%
  • (C)
    Inorganic clays of high plasticity with liquid limit less than 50%
  • (D)
    Inorganic clays of low plasticity with liquid limit more than 50%

Answer (official key): A

Worked solution: in your report after you take this paper.

Q22 · Water Resources Engineering · MCQ · 1 mark

The ratio of the momentum correction factor to the energy correction factor for a laminar flow in a pipe is

  • (A)
    12\frac{1}{2}
  • (B)
    23\frac{2}{3}
  • (C)
    1
  • (D)
    32\frac{3}{2}

Answer (official key): B

Worked solution: in your report after you take this paper.

Q23 · Transportation Engineering · MCQ · 1 mark

Relationship between traffic speed and density is described using a negatively sloped straight line. If vfv_f is the free-flow speed then the speed at which the maximum flow occurs is

  • (A)
    0
  • (B)
    vf4\frac{v_f}{4}
  • (C)
    vf2\frac{v_f}{2}
  • (D)
    vfv_f

Answer (official key): C

Worked solution: in your report after you take this paper.

Q24 · Environmental Engineering · MCQ · 1 mark

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

Assertion [a]: One of the best ways to reduce the amount of solid wastes is to reduce the consumption of raw materials.

Reason [r]: Solid wastes are seldom generated when raw materials are converted to goods for consumption.

  • (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)
    Both [a] and [r] are false
  • (D)
    [a] is true but [r] is false

Answer (official key): D

Worked solution: in your report after you take this paper.

Q25 · Environmental Engineering · MCQ · 1 mark

The hardness of a water sample is measured directly by titration with 0.01 M solution of ethylenediamine tetraacetic acid (EDTA) using eriochrome black T (EBT) as an indicator. The EBT reacts and forms complexes with divalent metallic cations present in the water. During titration, the EDTA replaces the EBT in the complex. When the replacement of EBT is complete at the end point of the titration, the colour of the solution changes from

  • (A)
    blue-green to reddish brown
  • (B)
    blue to colourless
  • (C)
    reddish brown to pinkish yellow
  • (D)
    wine red to blue

Answer (official key): D

Worked solution: in your report after you take this paper.

Q26 · Construction Materials and Management · MCQ · 1 mark

The softening point of bitumen has the same unit as that of

  • (A)
    distance
  • (B)
    temperature
  • (C)
    time
  • (D)
    viscosity

Answer (official key): B

Worked solution: in your report after you take this paper.

Q27 · Environmental Engineering · MSQ · 1 mark

Which of the following statement(s) is/are correct?

  • (A)
    Increased levels of carbon monoxide in the indoor environment result in the formation of carboxyhemoglobin and the long term exposure becomes a cause of cardiovascular diseases.
  • (B)
    Volatile organic compounds act as one of the precursors to the formation of photochemical smog in the presence of sunlight.
  • (C)
    Long term exposure to the increased level of photochemical smog becomes a cause of chest constriction and irritation of the mucous membrane.
  • (D)
    Increased levels of volatile organic compounds in the indoor environment will result in the formation of photochemical smog which is a cause of cardiovascular diseases.

Answer (official key): A, B, C

Read the worked solution

Q28 · Calculus · Numerical · 1 mark

The value (round off to one decimal place) of ∫−11x e∣x∣ dx\displaystyle\int_{-1}^{1} x\,e^{|x|}\,dx is ____________

Answer (official key): 0

Worked solution: in your report after you take this paper.

Q29 · Structural Engineering · Numerical · 1 mark

A solid circular torsional member OPQ is subjected to torsional moments as shown in the figure (not to scale). The yield shear strength of the constituent material is 160 MPa.

Figure for GATE 2021 CE (Set 2) question 29 (Structural Engineering)

The absolute maximum shear stress in the member (in MPa, round off to one decimal place) is ___________________

Answer (official key): 14 to 16

Worked solution: in your report after you take this paper.

Q30 · Structural Engineering · Numerical · 1 mark

A propped cantilever beam XY, with an internal hinge at the middle, is carrying a uniformly distributed load of 10 kN/m, as shown in the figure.

Figure for GATE 2021 CE (Set 2) question 30 (Structural Engineering)

The vertical reaction at support X (in kN, in integer) is _______________

Answer (official key): 30

Worked solution: in your report after you take this paper.

Q31 · Geotechnical Engineering · Numerical · 1 mark

The internal (did_i) and external (dod_o) diameters of a Shelby sampler are 48 mm and 52 mm, respectively. The area ratio (ArA_r) of the sampler (in %, round off to two decimal places) is ______________

Answer (official key): 17.25 to 17.45

Worked solution: in your report after you take this paper.

Q32 · Water Resources Engineering · Numerical · 1 mark

A 12-hour unit hydrograph (of 1 cm excess rainfall) of a catchment is of a triangular shape with a base width of 144 hour and a peak discharge of 23 m³/s. The area of the catchment (in km², round off to the nearest integer) is _______________

Answer (official key): 595 to 598

Worked solution: in your report after you take this paper.

Q33 · Water Resources Engineering · Numerical · 1 mark

A lake has a maximum depth of 60 m. If the mean atmospheric pressure in the lake region is 91 kPa and the unit weight of the lake water is 9790 N/m³, the absolute pressure (in kPa, round off to two decimal places) at the maximum depth of the lake is _______________

Answer (official key): 677.5 to 679.5

Worked solution: in your report after you take this paper.

Q34 · Transportation Engineering · Numerical · 1 mark

In a three-phase signal system design for a four-leg intersection, the critical flow ratios for each phase are 0.18, 0.32, and 0.22. The total loss time in each of the phases is 2 s. As per Webster’s formula, the optimal cycle length (in s, round off to the nearest integer) is __________________

Answer (official key): 48 to 52

Worked solution: in your report after you take this paper.

Q35 · Geomatics Engineering · Numerical · 1 mark

A horizontal angle θ is measured by four different surveyors multiple times and the values reported are given below.

SurveyorAngle θNumber of observations
136°30′4
236°00′3
335°30′8
436°30′4

The most probable value of the angle θ (in degree, round off to two decimal places) is ___________

Answer (official key): 36

Worked solution: in your report after you take this paper.

Q36 · Ordinary Differential Equations · MCQ · 2 marks

If kk is a constant, the general solution of dydx−yx=1\dfrac{dy}{dx} - \dfrac{y}{x} = 1 will be in the form of

  • (A)
    y=xln⁡(kx)y = x\ln(kx)
  • (B)
    y=kln⁡(kx)y = k\ln(kx)
  • (C)
    y=xln⁡(x)y = x\ln(x)
  • (D)
    y=xkln⁡(k)y = xk\ln(k)

Answer (official key): A

Worked solution: in your report after you take this paper.

Q37 · Linear Algebra · MCQ · 2 marks

The smallest eigenvalue and the corresponding eigenvector of the matrix [2−2−16]\begin{bmatrix} 2 & -2 \\ -1 & 6 \end{bmatrix}, respectively, are

  • (A)
    1.55 and {2.000.45}\begin{Bmatrix} 2.00 \\ 0.45 \end{Bmatrix}
  • (B)
    2.00 and {1.001.00}\begin{Bmatrix} 1.00 \\ 1.00 \end{Bmatrix}
  • (C)
    1.55 and {−2.55−0.45}\begin{Bmatrix} -2.55 \\ -0.45 \end{Bmatrix}
  • (D)
    1.55 and {2.00−0.45}\begin{Bmatrix} 2.00 \\ -0.45 \end{Bmatrix}

Answer (official key): A

Worked solution: in your report after you take this paper.

Q38 · Structural Engineering · MCQ · 2 marks

A prismatic steel beam is shown in the figure.

Figure for GATE 2021 CE (Set 2) question 38 (Structural Engineering)

The plastic moment, MpM_p calculated for the collapse mechanism using static method and kinematic method is

  • (A)
    Mp,static>2PL9=Mp,kinematicM_{p,\text{static}} > \dfrac{2PL}{9} = M_{p,\text{kinematic}}
  • (B)
    Mp,static=2PL9≠Mp,kinematicM_{p,\text{static}} = \dfrac{2PL}{9} \ne M_{p,\text{kinematic}}
  • (C)
    Mp,static=2PL9=Mp,kinematicM_{p,\text{static}} = \dfrac{2PL}{9} = M_{p,\text{kinematic}}
  • (D)
    Mp,static<2PL9=Mp,kinematicM_{p,\text{static}} < \dfrac{2PL}{9} = M_{p,\text{kinematic}}

Answer (official key): C

Worked solution: in your report after you take this paper.

Q39 · Structural Engineering · MCQ · 2 marks

A frame EFG is shown in the figure. All members are prismatic and have equal flexural rigidity. The member FG carries a uniformly distributed load w per unit length. Axial deformation of any member is neglected.

Figure for GATE 2021 CE (Set 2) question 39 (Structural Engineering)

Considering the joint F being rigid, the support reaction at G is

  • (A)
    0.375 wL
  • (B)
    0.453 wL
  • (C)
    0.482 wL
  • (D)
    0.500 wL

Answer (official key): C

Worked solution: in your report after you take this paper.

Q40 · Geotechnical Engineering · MCQ · 2 marks

A clay layer of thickness HH has a preconsolidation pressure pcp_c and an initial void ratio e0e_0. The initial effective overburden stress at the mid-height of the layer is p0p_0. At the same location, the increment in effective stress due to applied external load is Δp\Delta p. The compression and swelling indices of the clay are CcC_c and CsC_s, respectively. If p0<pc<(p0+Δp)p_0 < p_c < (p_0 + \Delta p), then the correct expression to estimate the consolidation settlement (sc)(s_c) of the clay layer is

  • (A)
    sc=H1+e0[Cclog⁡pcp0+Cslog⁡p0+Δppc]s_c = \dfrac{H}{1 + e_0}\left[C_c \log\dfrac{p_c}{p_0} + C_s \log\dfrac{p_0 + \Delta p}{p_c}\right]
  • (B)
    sc=H1+e0[Cslog⁡pcp0+Cclog⁡p0+Δppc]s_c = \dfrac{H}{1 + e_0}\left[C_s \log\dfrac{p_c}{p_0} + C_c \log\dfrac{p_0 + \Delta p}{p_c}\right]
  • (C)
    sc=H1+e0[Cclog⁡p0pc+Cslog⁡p0+Δppc]s_c = \dfrac{H}{1 + e_0}\left[C_c \log\dfrac{p_0}{p_c} + C_s \log\dfrac{p_0 + \Delta p}{p_c}\right]
  • (D)
    sc=H1+e0[Cslog⁡p0pc+Cclog⁡p0+Δppc]s_c = \dfrac{H}{1 + e_0}\left[C_s \log\dfrac{p_0}{p_c} + C_c \log\dfrac{p_0 + \Delta p}{p_c}\right]

Answer (official key): B

Worked solution: in your report after you take this paper.

Q41 · Water Resources Engineering · MCQ · 2 marks

A rectangular open channel of 6 m width is carrying a discharge of 20 m³/s. Consider the acceleration due to gravity as 9.81 m/s² and assume water as incompressible and inviscid. The depth of flow in the channel at which the specific energy of the flowing water is minimum for the given discharge will then be

  • (A)
    0.82 m
  • (B)
    1.04 m
  • (C)
    2.56 m
  • (D)
    3.18 m

Answer (official key): B

Worked solution: in your report after you take this paper.

Q42 · Environmental Engineering · MCQ · 2 marks

Read the statements given below.

(i) Value of the wind profile exponent for the ‘very unstable’ atmosphere is smaller than the wind profile exponent for the ‘neutral’ atmosphere.

(ii) Downwind concentration of air pollutants due to an elevated point source will be inversely proportional to the wind speed.

(iii) Value of the wind profile exponent for the ‘neutral’ atmosphere is smaller than the wind profile exponent for the ‘very unstable’ atmosphere.

(iv) Downwind concentration of air pollutants due to an elevated point source will be directly proportional to the wind speed.

Select the correct option.

  • (A)
    (i) is False and (iii) is True
  • (B)
    (i) is True and (iv) is True
  • (C)
    (ii) is False and (iii) is False
  • (D)
    (iii) is False and (iv) is False

Answer (official key): D

Worked solution: in your report after you take this paper.

Q43 · Environmental Engineering · MCQ · 2 marks

A water filtration unit is made of uniform-size sand particles of 0.4 mm diameter with a shape factor of 0.84 and specific gravity of 2.55. The depth of the filter bed is 0.70 m and the porosity is 0.35. The filter bed is to be expanded to a porosity of 0.65 by hydraulic backwash. If the terminal settling velocity of sand particles during backwash is 4.5 cm/s, the required backwash velocity is

  • (A)
    5.79×10−35.79 \times 10^{-3} m/s
  • (B)
    6.35×10−36.35 \times 10^{-3} m/s
  • (C)
    0.69 cm/s
  • (D)
    0.75 cm/s

Answer (official key): B

Worked solution: in your report after you take this paper.

Q44 · Geomatics Engineering · MCQ · 2 marks

For a given traverse, latitudes and departures are calculated and it is found that sum of latitudes is equal to +2.1 m and the sum of departures is equal to –2.8 m. The length and bearing of the closing error, respectively, are

  • (A)
    3.50 m and 53°7′48″ NW
  • (B)
    2.45 m and 53°7′48″ NW
  • (C)
    0.35 m and 53.13° SE
  • (D)
    3.50 m and 53.13° SE

Answer (official key): A

Worked solution: in your report after you take this paper.

Q45 · Geotechnical Engineering · MCQ · 2 marks

From laboratory investigations, the liquid limit, plastic limit, natural moisture content and flow index of a soil specimen are obtained as 60%, 27%, 32% and 27, respectively. The corresponding toughness index and liquidity index of the soil specimen, respectively, are

  • (A)
    0.15 and 1.22
  • (B)
    0.19 and 6.60
  • (C)
    1.22 and 0.15
  • (D)
    6.60 and 0.19

Answer (official key): C

Worked solution: in your report after you take this paper.

Q46 · Calculus · Numerical · 2 marks

A function is defined in Cartesian coordinate system as f(x,y)=xeyf(x, y) = xe^y. The value of the directional derivative of the function (in integer) at the point (2, 0) along the direction of the straight line segment from point (2, 0) to point (12,2)\left(\frac{1}{2}, 2\right) is _________________

Answer (official key): 1

Read the worked solution

Q47 · Structural Engineering · Numerical · 2 marks

An elevated cylindrical water storage tank is shown in the figure. The tank has inner diameter of 1.5 m. It is supported on a solid steel circular column of diameter 75 mm and total height (L) of 4 m. Take, water density = 1000 kg/m³ and acceleration due to gravity = 10 m/s².

Figure for GATE 2021 CE (Set 2) question 47 (Structural Engineering)

If elastic modulus (E) of steel is 200 GPa, ignoring self-weight of the tank, for the supporting steel column to remain unbuckled, the maximum depth (h) of the water permissible (in m, round off to one decimal place) is ___________

Answer (official key): 2.5 to 2.9

Read the worked solution

Q48 · Structural Engineering · Numerical · 2 marks

Not in GATE 2027 syllabus: Free vibration of undamped SDOF systems

A prismatic fixed-fixed beam, modelled with a total lumped-mass of 10 kg as a single degree of freedom (SDOF) system is shown in the figure.

Figure for GATE 2021 CE (Set 2) question 48 (Structural Engineering)

If the flexural stiffness of the beam is 42 kN/m, its natural frequency of vibration (in Hz, in integer) in the flexural mode will be __________

Answer (official key): 10

Worked solution: in your report after you take this paper.

Q49 · Structural Engineering · Numerical · 2 marks

A perfectly flexible and inextensible cable is shown in the figure (not to scale). The external loads at F and G are acting vertically.

Figure for GATE 2021 CE (Set 2) question 49 (Structural Engineering)

The magnitude of tension in the cable segment FG (in kN, round off to two decimal places) is ______________

Answer (official key): 8.1 to 8.4

Worked solution: in your report after you take this paper.

Q50 · Water Resources Engineering · Numerical · 2 marks

A fire hose nozzle directs a steady stream of water of velocity 50 m/s at an angle of 45° above the horizontal. The stream rises initially but then eventually falls to the ground. Assume water as incompressible and inviscid. Consider the density of air and the air friction as negligible, and assume the acceleration due to gravity as 9.81 m/s². The maximum height (in m, round off to two decimal places) reached by the stream above the hose nozzle will then be ________________

Answer (official key): 63.5 to 63.9

Worked solution: in your report after you take this paper.

Q51 · Structural Engineering · Numerical · 2 marks

A rectangular cross-section of a reinforced concrete beam is shown in the figure. The diameter of each reinforcing bar is 16 mm. The values of modulus of elasticity of concrete and steel are 2.0×10⁴ MPa and 2.1×10⁵ MPa, respectively.

Figure for GATE 2021 CE (Set 2) question 51 (Structural Engineering)

The distance of the centroidal axis from the centerline of the reinforcement (x) for the uncracked section (in mm, round off to one decimal place) is ___________________

Answer (official key): 129 to 130

Worked solution: in your report after you take this paper.

Q52 · Construction Materials and Management · Numerical · 2 marks

The activity details for a small project are given in the Table.

ActivityDuration (days)Depends on
A6-
B10A
C14A
D8B
E12C
F8C
G16D, E
H8F, G
K2B
L5G, K

The total time (in days, in integer) for project completion is ____________

Answer (official key): 56

Worked solution: in your report after you take this paper.

Q53 · Construction Materials and Management · Numerical · 2 marks

An equipment has been purchased at an initial cost of ₹160000 and has an estimated salvage value of ₹10000. The equipment has an estimated life of 5 years. The difference between the book values (in ₹, in integer) obtained at the end of 4th year using straight line method and sum of years digit method of depreciation is ______________

Answer (official key): 20000

Worked solution: in your report after you take this paper.

Q54 · Geotechnical Engineering · Numerical · 2 marks

A rectangular footing of size 2.8 m × 3.5 m is embedded in a clay layer and a vertical load is placed with an eccentricity of 0.8 m as shown in the figure (not to scale).

Figure for GATE 2021 CE (Set 2) question 54 (Geotechnical Engineering)

Take Bearing capacity factors: NcN_c = 5.14, NqN_q = 1.0, and NγN_\gamma = 0.0; Shape factors: scs_c = 1.16, sqs_q = 1.0 and sγs_\gamma = 1.0; Depth factors: dcd_c = 1.1, dqd_q = 1.0 and dγd_\gamma = 1.0; and Inclination factors: ici_c = 1.0 and iqi_q = 1.0 and iγi_\gamma = 1.0.

Using Meyerhoff’s method, the load (in kN, round off to two decimal places) that can be applied on the footing with a factor of safety of 2.5 is ___________

Answer (official key): 439 to 442

Worked solution: in your report after you take this paper.

Q55 · Geotechnical Engineering · Numerical · 2 marks

The soil profile at a road construction site is as shown in figure (not to scale). A large embankment is to be constructed at the site. The ground water table (GWT) is located at the surface of the clay layer, and the capillary rise in the sandy soil is negligible. The effective stress at the middle of the clay layer after the application of the embankment loading is 180 kN/m².

Figure for GATE 2021 CE (Set 2) question 55 (Geotechnical Engineering)

Take unit weight of water, γw\gamma_w = 9.81 kN/m³.

The primary consolidation settlement (in m, round off to two decimal places) of the clay layer resulting from this loading will be _____________

Answer (official key): 0.32 to 0.34

Worked solution: in your report after you take this paper.

Q56 · Numerical Methods · Numerical · 2 marks

Numerically integrate, f(x)=10x−20x2f(x) = 10x - 20x^2 from lower limit a=0a = 0 to upper limit b=0.5b = 0.5. Use Trapezoidal rule with five equal subdivisions. The value (in units, round off to two decimal places) obtained is ________________

Answer (official key): 0.38 to 0.42

Worked solution: in your report after you take this paper.

Q57 · Geotechnical Engineering · Numerical · 2 marks

The void ratio of a clay soil sample M decreased from 0.575 to 0.510 when the applied pressure is increased from 120 kPa to 180 kPa. For the same increment in pressure, the void ratio of another clay soil sample N decreases from 0.600 to 0.550. If the ratio of hydraulic conductivity of sample M to sample N is 0.125, then the ratio of coefficient of consolidation of sample M to sample N (round off to three decimal places) is ______________

Answer (official key): 0.09 to 0.105

Worked solution: in your report after you take this paper.

Q58 · Water Resources Engineering · Numerical · 2 marks

The hyetograph in the figure corresponds to a rainfall event of 3 cm.

Figure for GATE 2021 CE (Set 2) question 58 (Water Resources Engineering)

If the rainfall event has produced a direct runoff of 1.6 cm, the φ-index of the event (in mm/hour, round off to one decimal place) would be ____________

Answer (official key): 4.2

Worked solution: in your report after you take this paper.

Q59 · Water Resources Engineering · Numerical · 2 marks

A venturimeter as shown in the figure (not to scale) is connected to measure the flow of water in a vertical pipe of 20 cm diameter. Assume g = 9.8 m/s².

Figure for GATE 2021 CE (Set 2) question 59 (Water Resources Engineering)

When the deflection in the mercury manometer is 15 cm, the flow rate (in lps, round off to two decimal places) considering no loss in the venturimeter is ______________

Answer (official key): 49 to 50

Worked solution: in your report after you take this paper.

Q60 · Water Resources Engineering · Numerical · 2 marks

A reservoir with a live storage of 300 million cubic metre irrigates 40000 hectares (1 hectare = 10⁴ m²) of a crop with two fillings of the reservoir. If the base period of the crop is 120 days, the duty for this crop (in hectares per cumec, round off to integer) will then be ______________

Answer (official key): 689 to 693

Worked solution: in your report after you take this paper.

Q61 · Environmental Engineering · Numerical · 2 marks

An activated sludge process (ASP) is designed for secondary treatment of 7500 m³/day of municipal wastewater. After primary clarifier, the ultimate BOD of the influent, which enters into ASP reactor is 200 mg/L. Treated effluent after secondary clarifier is required to have an ultimate BOD of 20 mg/L. Mix liquor volatile suspended solids (MLVSS) concentration in the reactor and the underflow is maintained as 3000 mg/L and 12000 mg/L, respectively. The hydraulic retention time and mean cell residence time are 0.2 day and 10 days, respectively. A representative flow diagram of the ASP is shown below.

Figure for GATE 2021 CE (Set 2) question 61 (Environmental Engineering)

The underflow volume (in m³/day, round off to one decimal place) of sludge wastage is ______________

Answer (official key): 37 to 38

Worked solution: in your report after you take this paper.

Q62 · Environmental Engineering · Numerical · 2 marks

A grit chamber of rectangular cross-section is to be designed to remove particles with diameter of 0.25 mm and specific gravity of 2.70. The terminal settling velocity of the particles is estimated as 2.5 cm/s. The chamber is having a width of 0.50 m and has to carry a peak wastewater flow of 9720 m³/d giving the depth of flow as 0.75 m. If a flow-through velocity of 0.3 m/s has to be maintained using a proportional weir at the outlet end of the chamber, the minimum length of the chamber (in m, in integer) to remove 0.25 mm particles completely is ______________

Answer (official key): 9

Worked solution: in your report after you take this paper.

Q63 · Transportation Engineering · Numerical · 2 marks

In an aggregate mix, the proportions of coarse aggregate, fine aggregate and mineral filler are 55%, 40% and 5%, respectively. The values of bulk specific gravity of the coarse aggregate, fine aggregate and mineral filler are 2.55, 2.65 and 2.70, respectively. The bulk specific gravity of the aggregate mix (round off to two decimal places) is _______________

Answer (official key): 2.58 to 2.61

Worked solution: in your report after you take this paper.

Q64 · Transportation Engineering · Numerical · 2 marks

The stopping sight distance (SSD) for a level highway is 140 m for the design speed of 90 km/h. The acceleration due to gravity and deceleration rate are 9.81 m/s² and 3.5 m/s², respectively. The perception/reaction time (in s, round off to two decimal places) used in the SSD calculation is _____________

Answer (official key): 1.9 to 2.1

Worked solution: in your report after you take this paper.

Q65 · Transportation Engineering · Numerical · 2 marks

For a 2° curve on a high speed Broad Gauge (BG) rail section, the maximum sanctioned speed is 100 km/h and the equilibrium speed is 80 km/h. Consider dynamic gauge of BG rail as 1750 mm. The degree of curve is defined as the angle subtended at its center by a 30.5 m arc. The cant deficiency for the curve (in mm, round off to integer) is _______________

Answer (official key): 55 to 59

Worked solution: in your report after you take this paper.