GATE 2020 ME (Set 2)

All 65 questions of GATE 2020 ME (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

While I agree_____his proposal this time, I do not often agree_____him.

  • (A)
    to, with
  • (B)
    with, to
  • (C)
    with, with
  • (D)
    to, to

Answer (official key): A

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

Q2 · General Aptitude · MCQ · 1 mark

The recent measures to improve the output would_____the level of production to our satisfaction.

  • (A)
    increase
  • (B)
    decrease
  • (C)
    speed
  • (D)
    equalise

Answer (official key): A

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

Q3 · General Aptitude · MCQ · 1 mark

Select the word that fits the analogy:

White: Whitening : : Light: _____

  • (A)
    Lightning
  • (B)
    Lightening
  • (C)
    Lighting
  • (D)
    Enlightening

Answer (official key): B

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

Q4 · General Aptitude · MCQ · 1 mark

In one of the greatest innings ever seen in 142 years of Test history, Ben Stokes upped the tempo in a five-and-a-half hour long stay of 219 balls including 11 fours and 8 sixes that saw him finish on a 135 not out as England squared the five-match series.

Based on their connotations in the given passage, which one of the following meanings DOES NOT match?

  • (A)
    upped = increased
  • (B)
    squared = lost
  • (C)
    tempo = enthusiasm
  • (D)
    saw = resulted in

Answer (official key): B

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

Q5 · General Aptitude · MCQ · 1 mark

There are five levels {P, Q, R, S, T} in a linear supply chain before a product reaches customers, as shown in the figure.

Figure for GATE 2020 ME (Set 2) question 5 (Quantitative Aptitude)

At each of the five levels, the price of the product is increased by 25%25\%. If the product is produced at level P at the cost of Rs. 120 per unit, what is the price paid (in rupees) by the customers?

  • (A)
    187.50187.50
  • (B)
    234.38234.38
  • (C)
    292.96292.96
  • (D)
    366.21366.21

Answer (official key): D

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

Q6 · General Aptitude · MCQ · 2 marks

Climate change and resilience deal with two aspects – reduction of sources of non-renewable energy resources and reducing vulnerability of climate change aspects. The terms ‘mitigation’ and ‘adaptation’ are used to refer to these aspects, respectively.

Which of the following assertions is best supported by the above information?

  • (A)
    Mitigation deals with consequences of climate change.
  • (B)
    Adaptation deals with causes of climate change.
  • (C)
    Mitigation deals with actions taken to reduce the use of fossil fuels.
  • (D)
    Adaptation deals with actions taken to combat green-house gas emissions.

Answer (official key): C

Read the worked solution

Q7 · General Aptitude · MCQ · 2 marks

Find the missing element in the following figure.

Figure for GATE 2020 ME (Set 2) question 7 (Analytical Aptitude)

  • (A)
    dd
  • (B)
    ee
  • (C)
    ww
  • (D)
    yy

Answer (official key): A

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

Q8 · General Aptitude · MCQ · 2 marks

It was estimated that 52 men can complete a strip in a newly constructed highway connecting cities P and Q in 10 days. Due to an emergency, 12 men were sent to another project. How many number of days, more than the original estimate, will be required to complete the strip?

  • (A)
    3 days
  • (B)
    5 days
  • (C)
    10 days
  • (D)
    13 days

Answer (official key): A

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

Q9 · General Aptitude · MCQ · 2 marks

An engineer measures THREE quantities X, Y and Z in an experiment. She finds that they follow a relationship that is represented in the figure below: (the product of X and Y linearly varies with Z)

Figure for GATE 2020 ME (Set 2) question 9 (Quantitative Aptitude)

Then, which of the following statements is FALSE?

  • (A)
    For fixed ZZ; XX is proportional to YY
  • (B)
    For fixed YY; XX is proportional to ZZ
  • (C)
    For fixed XX; ZZ is proportional to YY
  • (D)
    XY/ZXY/Z is constant

Answer (official key): A

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

Q10 · General Aptitude · MCQ · 2 marks

The two pie-charts given below show the data of total students and only girls registered in different streams in a university. If the total number of students registered in the university is 5000, and the total number of the registered girls is 1500; then, the ratio of boys enrolled in Arts to the girls enrolled in Management is _____.

Figure for GATE 2020 ME (Set 2) question 10 (Quantitative Aptitude)

  • (A)
    2:12:1
  • (B)
    9:229:22
  • (C)
    11:911:9
  • (D)
    22:922:9

Answer (official key): D

Read the worked solution

Q11 · Probability and Statistics · MCQ · 1 mark

The sum of two normally distributed random variables X and Y is

  • (A)
    always normally distributed
  • (B)
    normally distributed, only if X and Y are independent
  • (C)
    normally distributed, only if X and Y have the same standard deviation
  • (D)
    normally distributed, only if X and Y have the same mean

Answer (official key): Marks to all

Everyone who took this paper got the marks for this question. Marks to all in GATE

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

Q12 · Linear Algebra · MCQ · 1 mark

A matrix PP is decomposed into its symmetric part SS and skew symmetric part VV.

If

S=(−442437/227/22),V=(0−23207/2−3−7/20),S=\begin{pmatrix}-4&4&2\\4&3&7/2\\2&7/2&2\end{pmatrix},\quad V=\begin{pmatrix}0&-2&3\\2&0&7/2\\-3&-7/2&0\end{pmatrix},

then matrix PP is

  • (A)
    (−46−1230572)\begin{pmatrix}-4&6&-1\\2&3&0\\5&7&2\end{pmatrix}
  • (B)
    (−425637−102)\begin{pmatrix}-4&2&5\\6&3&7\\-1&0&2\end{pmatrix}
  • (C)
    (4−61−2−30−5−7−2)\begin{pmatrix}4&-6&1\\-2&-3&0\\-5&-7&-2\end{pmatrix}
  • (D)
    (−29/2−1−181/411−245/273/4)\begin{pmatrix}-2&9/2&-1\\-1&81/4&11\\-2&45/2&73/4\end{pmatrix}

Answer (official key): B

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

Q13 · Calculus · MCQ · 1 mark

Let I=∫x=01∫y=0x2xy2 dy dxI=\int_{x=0}^{1}\int_{y=0}^{x^2}xy^2\,dy\,dx. Then, II may also be expressed as

  • (A)
    ∫y=01∫x=0yxy2 dx dy\displaystyle\int_{y=0}^{1}\int_{x=0}^{\sqrt{y}}xy^2\,dx\,dy
  • (B)
    ∫y=01∫x=y1yx2 dx dy\displaystyle\int_{y=0}^{1}\int_{x=\sqrt{y}}^{1}yx^2\,dx\,dy
  • (C)
    ∫y=01∫x=y1xy2 dx dy\displaystyle\int_{y=0}^{1}\int_{x=\sqrt{y}}^{1}xy^2\,dx\,dy
  • (D)
    ∫y=01∫x=0yyx2 dx dy\displaystyle\int_{y=0}^{1}\int_{x=0}^{\sqrt{y}}yx^2\,dx\,dy

Answer (official key): C

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

Q14 · Differential Equations · MCQ · 1 mark

The solution of

d2ydt2−y=1,\frac{d^2y}{dt^2}-y=1,

which additionally satisfies y∣t=0=dydt∣t=0=0y|_{t=0}=\left.\frac{dy}{dt}\right|_{t=0}=0 in the Laplace ss-domain is

  • (A)
    1s(s+1)(s−1)\displaystyle\frac{1}{s(s+1)(s-1)}
  • (B)
    1s(s+1)\displaystyle\frac{1}{s(s+1)}
  • (C)
    1s(s−1)\displaystyle\frac{1}{s(s-1)}
  • (D)
    1s−1\displaystyle\frac{1}{s-1}

Answer (official key): A

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

Q15 · Applied Mechanics · MCQ · 1 mark

An attempt is made to pull a roller of weight WW over a curb (step) by applying a horizontal force FF as shown in the figure.

Figure for GATE 2020 ME (Set 2) question 15 (Applied Mechanics)

The coefficient of static friction between the roller and the ground (including the edge of the step) is μ\mu. Identify the correct free body diagram (FBD) of the roller when the roller is just about to climb over the step.

  • (A)
    GATE 2020 ME (Set 2) question 15 (Applied Mechanics), option A
  • (B)
    GATE 2020 ME (Set 2) question 15 (Applied Mechanics), option B
  • (C)
    GATE 2020 ME (Set 2) question 15 (Applied Mechanics), option C
  • (D)
    GATE 2020 ME (Set 2) question 15 (Applied Mechanics), option D

Answer (official key): B

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

Q16 · Applied Mechanics · MCQ · 1 mark

A circular disk of radius rr is confined to roll without slipping at P and Q as shown in the figure.

Figure for GATE 2020 ME (Set 2) question 16 (Applied Mechanics)

If the plates have velocities as shown, the magnitude of angular velocity of the disk is

  • (A)
    vr\displaystyle\frac{v}{r}
  • (B)
    v2r\displaystyle\frac{v}{2r}
  • (C)
    2v3r\displaystyle\frac{2v}{3r}
  • (D)
    3v2r\displaystyle\frac{3v}{2r}

Answer (official key): D

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

Q17 · Vibrations · MCQ · 1 mark

The equation of motion of a spring-mass-damper system is given by

d2xdt2+3dxdt+9x=10sin⁡(5t)\frac{d^2x}{dt^2}+3\frac{dx}{dt}+9x=10\sin(5t)

The damping factor for the system is

  • (A)
    0.250.25
  • (B)
    0.50.5
  • (C)
    22
  • (D)
    33

Answer (official key): B

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

Q18 · Theory of Machines · MCQ · 1 mark

The number of qualitatively distinct kinematic inversions possible for a Grashof chain with four revolute pairs is

  • (A)
    11
  • (B)
    22
  • (C)
    33
  • (D)
    44

Answer (official key): C

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

Q19 · Manufacturing Engineering · MCQ · 1 mark

The process, that uses a tapered horn to amplify and focus the mechanical energy for machining of glass, is

  • (A)
    electrochemical machining
  • (B)
    electrical discharge machining
  • (C)
    ultrasonic machining
  • (D)
    abrasive jet machining

Answer (official key): C

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

Q20 · Manufacturing Engineering · MCQ · 1 mark

Two plates, each of 66 mm thickness, are to be butt-welded. Consider the following processes and select the correct sequence in increasing order of size of the heat affected zone.

  1. Arc welding
  2. MIG welding
  3. Laser beam welding
  4. Submerged arc welding
  • (A)
    1-4-2-3
  • (B)
    3-4-2-1
  • (C)
    4-3-2-1
  • (D)
    3-2-4-1

Answer (official key): D

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

Q21 · Engineering Materials · MCQ · 1 mark

Which one of the following statements about a phase diagram is INCORRECT?

  • (A)
    It indicates the temperature at which different phases start to melt
  • (B)
    Relative amount of different phases can be found under given equilibrium conditions
  • (C)
    It gives information on transformation rates
  • (D)
    Solid solubility limits are depicted by it

Answer (official key): C

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

Q22 · Manufacturing Engineering · MCQ · 1 mark

The figure below shows a symbolic representation of the surface texture in a perpendicular lay orientation with indicative values (I through VI) marking the various specifications whose definitions are listed below.

P: Maximum Waviness Height (mm); Q: Maximum Roughness Height (mm);

R: Minimum Roughness Height (mm); S: Maximum Waviness Width (mm);

T: Maximum Roughness Width (mm); U: Roughness Width Cutoff (mm).

Figure for GATE 2020 ME (Set 2) question 22 (Manufacturing Engineering)

The correct match between the specifications and the symbols (I to VI) is

  • (A)
    I-R, II-Q, III-P, IV-S, V-U, VI-T
  • (B)
    I-R, II-P, III-U, IV-S, V-T, VI-Q
  • (C)
    I-U, II-S, III-Q, IV-T, V-R, VI-P
  • (D)
    I-Q, II-U, III-R, IV-T, V-S, VI-P

Answer (official key): A

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

Q23 · Industrial Engineering · MCQ · 1 mark

In Materials Requirement Planning, if the inventory holding cost is very high and the setup cost is zero, which one of the following lot sizing approaches should be used?

  • (A)
    Economic Order Quantity
  • (B)
    Lot-for-Lot
  • (C)
    Base Stock Level
  • (D)
    Fixed Period Quantity, for 2 periods

Answer (official key): B

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

Q24 · Fluid Mechanics · MCQ · 1 mark

Which of the following conditions is used to determine the stable equilibrium of all partially submerged floating bodies?

  • (A)
    Centre of buoyancy must be above the centre of gravity
  • (B)
    Centre of buoyancy must be below the centre of gravity
  • (C)
    Metacentre must be at a higher level than the centre of gravity
  • (D)
    Metacentre must be at a lower level than the centre of gravity

Answer (official key): C

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

Q25 · Fluid Mechanics · MCQ · 1 mark

In the space above the mercury column in a barometer tube, the gauge pressure of the vapour is

  • (A)
    positive, but more than one atmosphere
  • (B)
    negative
  • (C)
    zero
  • (D)
    positive, but less than one atmosphere

Answer (official key): B

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

Q26 · Thermodynamics · MCQ · 1 mark

A closed vessel contains pure water, in thermal equilibrium with its vapour at 25∘C25^\circ\mathrm{C} (Stage #1), as shown.

Figure for GATE 2020 ME (Set 2) question 26 (Thermodynamics)

The vessel in this stage is then kept inside an isothermal oven which is having an atmosphere of hot air maintained at 80∘C80^\circ\mathrm{C}. The vessel exchanges heat with the oven atmosphere and attains a new thermal equilibrium (Stage #2). If the Valve A is now opened inside the oven, what will happen immediately after opening the valve?

  • (A)
    Water vapor inside the vessel will come out of the Valve A
  • (B)
    Hot air will go inside the vessel through Valve A
  • (C)
    Nothing will happen – the vessel will continue to remain in equilibrium
  • (D)
    All the vapor inside the vessel will immediately condense

Answer (official key): B

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

Q27 · Thermodynamics · MCQ · 1 mark

For an air-standard Diesel cycle,

  • (A)
    heat addition is at constant volume and heat rejection is at constant pressure
  • (B)
    heat addition is at constant pressure and heat rejection is at constant pressure
  • (C)
    heat addition is at constant pressure and heat rejection is at constant volume
  • (D)
    heat addition is at constant volume and heat rejection is at constant volume

Answer (official key): C

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

Q28 · Fluid Mechanics · MCQ · 1 mark

The values of enthalpies at the stator inlet and rotor outlet of a hydraulic turbomachine stage are h1h_1 and h3h_3 respectively. The enthalpy at the stator outlet (or rotor inlet) is h2h_2. The condition (h2−h1)=(h3−h2)(h_2-h_1)=(h_3-h_2) indicates that the degree of reaction of this stage is

  • (A)
    zero
  • (B)
    50%50\%
  • (C)
    75%75\%
  • (D)
    100%100\%

Answer (official key): B

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

Q29 · Linear Algebra · Numerical · 1 mark

Let I\mathbf{I} be a 100100 dimensional identity matrix and E\mathbf{E} be the set of distinct (no value appears more than once in E\mathbf{E}) real eigenvalues. The number of elements in E\mathbf{E} is _______________.

Answer (official key): 1

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

Q30 · Applied Mechanics · Numerical · 1 mark

A beam of negligible mass is hinged at support P and has a roller support Q as shown in the figure.

Figure for GATE 2020 ME (Set 2) question 30 (Applied Mechanics)

A point load of 12001200 N is applied at point R. The magnitude of the reaction force at support Q is ______ N.

Answer (official key): 1500

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

Q31 · Machine Design · Numerical · 1 mark

A machine member is subjected to fluctuating stress σ=σ0cos⁡(8πt)\sigma=\sigma_0\cos(8\pi t). The endurance limit of the material is 350350 MPa. If the factor of safety used in the design is 3.53.5 then the maximum allowable value of σ0\sigma_0 is _______________ MPa (round off to 2 decimal places).

Answer (official key): 99.98 to 100.02

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

Q32 · Manufacturing Engineering · Numerical · 1 mark

A bolt head has to be made at the end of a rod of diameter d=12d=12 mm by localized forging (upsetting) operation. The length of the unsupported portion of the rod is 4040 mm. To avoid buckling of the rod, a closed forging operation has to be performed with a maximum die diameter of ________mm.

Answer (official key): 18 to 19.5

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

Q33 · Industrial Engineering · Numerical · 1 mark

Consider the following network of activities, with each activity named A–L, illustrated in the nodes of the network.

Figure for GATE 2020 ME (Set 2) question 33 (Industrial Engineering)

The number of hours required for each activity is shown alongside the nodes. The slack on the activity L, is _______hours.

Answer (official key): 2

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

Q34 · Heat Transfer · Numerical · 1 mark

In a furnace, the inner and outer sides of the brick wall (k1=2.5k_1 = 2.5 W/m.K) are maintained at 1100∘C1100^\circ\mathrm{C} and 700∘C700^\circ\mathrm{C}, respectively as shown in figure.

Figure for GATE 2020 ME (Set 2) question 34 (Heat Transfer)

The brick wall is covered by an insulating material of thermal conductivity k2k_2. The thickness of the insulation is 1/4th1/4^{\text{th}} of the thickness of the brick wall. The outer surface of the insulation is at 200∘C200^\circ\mathrm{C}. The heat flux through the composite walls is 25002500 W/m2^2.

The value of k2k_2 is _____ W/m.K (round off to one decimal place).

Answer (official key): 0.5

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

Q35 · Thermodynamics · Numerical · 1 mark

If a reversed Carnot cycle operates between the temperature limits of 27∘C27^\circ\mathrm{C} and −3∘C-3^\circ\mathrm{C}, then the ratio of the COP of a refrigerator to that of a heat pump (COP of refrigerator / COP of heat pump) based on the cycle is ______________ (round off to 2 decimal places).

Answer (official key): 0.89 to 0.91

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

Q36 · Calculus · MCQ · 2 marks

The directional derivative of f(x,y,z)=xyzf(x,y,z)=xyz at point (−1,1,3)(-1,1,3) in the direction of vector i^−2j^+2k^\hat{i}-2\hat{j}+2\hat{k} is

  • (A)
    3i^−3j^−k^3\hat{i}-3\hat{j}-\hat{k}
  • (B)
    −73-\dfrac{7}{3}
  • (C)
    73\dfrac{7}{3}
  • (D)
    77

Answer (official key): C

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

Q37 · Complex Variables · MCQ · 2 marks

The function f(z)f(z) of complex variable z=x+iyz=x+iy, where i=−1i=\sqrt{-1}, is given as f(z)=(x3−3xy2)+iv(x,y)f(z)=(x^3-3xy^2)+iv(x,y). For this function to be analytic, v(x,y)v(x,y) should be

  • (A)
    (3xy2−y3)+constant(3xy^2-y^3)+\text{constant}
  • (B)
    (3x2y2−y3)+constant(3x^2y^2-y^3)+\text{constant}
  • (C)
    (x3−3x2y)+constant(x^3-3x^2y)+\text{constant}
  • (D)
    (3x2y−y3)+constant(3x^2y-y^3)+\text{constant}

Answer (official key): D

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

Q38 · Mechanics of Materials · MCQ · 2 marks

A cantilever of length ll, and flexural rigidity EIEI, stiffened by a spring of stiffness kk, is loaded by a transverse force PP, as shown.

Figure for GATE 2020 ME (Set 2) question 38 (Mechanics of Materials)

The transverse deflection under the load is

  • (A)
    Pl33EI[3EI3EI+2kl3]\dfrac{Pl^3}{3EI}\left[\dfrac{3EI}{3EI+2kl^3}\right]
  • (B)
    Pl33EI[6EI−kl36EI]\dfrac{Pl^3}{3EI}\left[\dfrac{6EI-kl^3}{6EI}\right]
  • (C)
    Pl33EI[3EI−kl33EI]\dfrac{Pl^3}{3EI}\left[\dfrac{3EI-kl^3}{3EI}\right]
  • (D)
    Pl33EI[3EI3EI+kl3]\dfrac{Pl^3}{3EI}\left[\dfrac{3EI}{3EI+kl^3}\right]

Answer (official key): D

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

Q39 · Theory of Machines · MCQ · 2 marks

The sun (S) and the planet (P) of an epicyclic gear train shown in the figure have identical number of teeth.

Figure for GATE 2020 ME (Set 2) question 39 (Theory of Machines)

If the sun (S) and the outer ring (R) gears are rotated in the same direction with angular speed ωS\omega_S and ωR\omega_R, respectively, then the angular speed of the arm AB is

  • (A)
    34ωR+14ωS\dfrac{3}{4}\omega_R+\dfrac{1}{4}\omega_S
  • (B)
    14ωR+34ωS\dfrac{1}{4}\omega_R+\dfrac{3}{4}\omega_S
  • (C)
    12ωR−12ωS\dfrac{1}{2}\omega_R-\dfrac{1}{2}\omega_S
  • (D)
    34ωR−14ωS\dfrac{3}{4}\omega_R-\dfrac{1}{4}\omega_S

Answer (official key): A

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

Q40 · Mechanics of Materials · MCQ · 2 marks

A thin-walled cylinder of radius rr and thickness tt is open at both ends, and fits snugly between two rigid walls under ambient conditions, as shown in the figure.

Figure for GATE 2020 ME (Set 2) question 40 (Mechanics of Materials)

The material of the cylinder has Young’s modulus EE, Poisson’s ratio ν\nu and coefficient of thermal expansion α\alpha. What is the minimum rise in temperature ΔT\Delta T of the cylinder (assume uniform cylinder temperature with no buckling of the cylinder) required to prevent gas leakage if the cylinder has to store the gas at an internal pressure of pp above the atmosphere?

  • (A)
    ΔT=3νpr2αtE\Delta T=\dfrac{3\nu pr}{2\alpha tE}
  • (B)
    ΔT=(ν−14)prαtE\Delta T=\left(\nu-\dfrac{1}{4}\right)\dfrac{pr}{\alpha tE}
  • (C)
    ΔT=νprαtE\Delta T=\dfrac{\nu pr}{\alpha tE}
  • (D)
    ΔT=(ν+12)prαtE\Delta T=\left(\nu+\dfrac{1}{2}\right)\dfrac{pr}{\alpha tE}

Answer (official key): C

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

Q41 · Machine Design · MCQ · 2 marks

A helical spring has spring constant kk. If the wire diameter, spring diameter and the number of coils are all doubled then the spring constant of the new spring becomes

  • (A)
    k/2k/2
  • (B)
    kk
  • (C)
    8k8k
  • (D)
    16k16k

Answer (official key): B

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

Q42 · Manufacturing Engineering · MCQ · 2 marks

Two rollers of diameters D1D_1 (in mm) and D2D_2 (in mm) are used to measure the internal taper angle in the V-groove of a machined component. The heights H1H_1 (in mm) and H2H_2 (in mm) are measured by using a height gauge after inserting the rollers into the same V-groove as shown in the figure.

Figure for GATE 2020 ME (Set 2) question 42 (Manufacturing Engineering)

Which one of the following is the correct relationship to evaluate the angle α\alpha as shown in the figure?

  • (A)
    sin⁡α=D1−D22(H1−H2)−(D1−D2)\sin\alpha=\dfrac{D_1-D_2}{2(H_1-H_2)-(D_1-D_2)}
  • (B)
    cos⁡α=D1−D22(H1−H2)−2(D1−D2)\cos\alpha=\dfrac{D_1-D_2}{2(H_1-H_2)-2(D_1-D_2)}
  • (C)
    cosec⁡α=(H1−H2)−(D1−D2)2(D1−D2)\operatorname{cosec}\alpha=\dfrac{(H_1-H_2)-(D_1-D_2)}{2(D_1-D_2)}
  • (D)
    sin⁡α=H1−H2D1−D2\sin\alpha=\dfrac{H_1-H_2}{D_1-D_2}

Answer (official key): A

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

Q43 · Industrial Engineering · MCQ · 2 marks

The forecast for the monthly demand of a product is given in the table below.

MonthForecastActual Sales
1132.0032.0030.0030.00
2231.8031.8032.0032.00
3331.8231.8230.0030.00

The forecast is made by using the exponential smoothing method. The exponential smoothing coefficient used in forecasting the demand is

  • (A)
    0.100.10
  • (B)
    0.400.40
  • (C)
    0.500.50
  • (D)
    1.001.00

Answer (official key): A

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

Q44 · Thermodynamics · MCQ · 2 marks

One kg of air in a closed system undergoes an irreversible process from an initial state of p1=1p_1=1 bar (absolute) and T1=27∘CT_1=27^\circ\mathrm{C}, to a final state of p2=3p_2=3 bar (absolute) and T2=127∘CT_2=127^\circ\mathrm{C}. If the gas constant of air is 287287 J/kg.K and the ratio of the specific heats γ=1.4\gamma=1.4, then the change in the specific entropy (in J/kg.K) of the air in the process is

  • (A)
    −26.3-26.3
  • (B)
    28.428.4
  • (C)
    172.0172.0
  • (D)
    indeterminate, as the process is irreversible

Answer (official key): A

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

Q45 · Numerical Methods · Numerical · 2 marks

For the integral ∫0π/2(8+4cos⁡x) dx\int_0^{\pi/2}(8+4\cos x)\,dx, the absolute percentage error in numerical evaluation with the Trapezoidal rule, using only the end points, is __________ (round off to one decimal place).

Answer (official key): 5.1 to 5.5

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

Q46 · Probability and Statistics · Numerical · 2 marks

A fair coin is tossed 2020 times. The probability that ‘head’ will appear exactly 44 times in the first ten tosses, and ‘tail’ will appear exactly 44 times in the next ten tosses is ______________ (round off to 3 decimal places).

Answer (official key): 0.041 to 0.043

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

Q47 · Vibrations · Numerical · 2 marks

A hollow spherical ball of radius 2020 cm floats in still water, with half of its volume submerged. Taking the density of water as 10001000 kg/m3^3, and the acceleration due to gravity as 1010 m/s2^2, the natural frequency of small oscillations of the ball, normal to the water surface is ____________ radians/s (round off to 2 decimal places).

Answer (official key): 8.6 to 8.7

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

Q48 · Mechanics of Materials · Numerical · 2 marks

Uniaxial compression test data for a solid metal bar of length 11 m is shown in the figure.

Figure for GATE 2020 ME (Set 2) question 48 (Mechanics of Materials)

The bar material has a linear elastic response from O to P followed by a nonlinear response. The point P represents the yield point of the material. The rod is pinned at both the ends. The minimum diameter of the bar so that it does not buckle under axial loading before reaching the yield point is ________ mm (round off to one decimal place).

Answer (official key): 55 to 58

Read the worked solution

Q49 · Theory of Machines · Numerical · 2 marks

The turning moment diagram of a flywheel fitted to a fictitious engine is shown in the figure.

Figure for GATE 2020 ME (Set 2) question 49 (Theory of Machines)

The mean turning moment is 20002000 Nm. The average engine speed is 10001000 rpm. For fluctuation in the speed to be within ±2%\pm2\% of the average speed, the mass moment of inertia of the flywheel is ______________ kg.m2^2.

Answer (official key): 3.55 to 3.65

Read the worked solution

Q50 · Applied Mechanics · Numerical · 2 marks

A rigid block of mass m1=10m_1=10 kg having velocity v0=2v_0=2 m/s strikes a stationary block of mass m2=30m_2=30 kg after traveling 11 m along a frictionless horizontal surface as shown in the figure.

Figure for GATE 2020 ME (Set 2) question 50 (Applied Mechanics)

The two masses stick together and jointly move by a distance of 0.250.25 m further along the same frictionless surface, before they touch the mass-less buffer that is connected to the rigid vertical wall by means of a linear spring having a spring constant k=105k=10^5 N/m. The maximum deflection of the spring is ______________ cm (round off to 2 decimal places).

Answer (official key): 0.98 to 1.02

Read the worked solution

Q51 · Machine Design · Numerical · 2 marks

A steel spur pinion has a module (mm) of 1.251.25 mm, 2020 teeth and 20∘20^\circ pressure angle. The pinion rotates at 12001200 rpm and transmits power to a 6060 teeth gear. The face width (FF) is 5050 mm, Lewis form factor Y=0.322Y=0.322 and a dynamic factor Kv=1.26K_v=1.26. The bending stress (σ\sigma) induced in a tooth can be calculated by using the Lewis formula given below.

If the maximum bending stress experienced by the pinion is 400400 MPa, the power transmitted is _________ kW (round off to one decimal place).

Lewis formula: σ=KvWtFmY\sigma=\dfrac{K_vW^t}{FmY}, where WtW^t is the tangential load acting on the pinion.

Answer (official key): 9.8 to 10.8

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

Q52 · Manufacturing Engineering · Numerical · 2 marks

A mould cavity of 12001200 cm3^3 volume has to be filled through a sprue of 1010 cm length feeding a horizontal runner. Cross-sectional area at the base of the sprue is 22 cm2^2. Consider acceleration due to gravity as 9.819.81 m/s2^2. Neglecting frictional losses due to molten metal flow, the time taken to fill the mould cavity is __________ seconds (round off to 2 decimal places).

Answer (official key): 4 to 9

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

Q53 · Manufacturing Engineering · Numerical · 2 marks

A cylindrical bar with 200200 mm diameter is being turned with a tool having geometry 0∘0^\circ - 9∘9^\circ - 7∘7^\circ - 8∘8^\circ - 15∘15^\circ - 30∘30^\circ - 0.050.05 inch (Coordinate system, ASA) resulting in a cutting force Fc1F_{c1}. If the tool geometry is changed to 0∘0^\circ - 9∘9^\circ - 7∘7^\circ - 8∘8^\circ - 15∘15^\circ - 0∘0^\circ - 0.050.05 inch (Coordinate system, ASA) and all other parameters remain unchanged, the cutting force changes to Fc2F_{c2}. Specific cutting energy (in J/mm3^3) is Uc=U0(t1)−0.4U_c=U_0(t_1)^{-0.4}, where U0U_0 is the specific energy coefficient, and t1t_1 is the uncut thickness in mm. The value of percentage change in cutting force Fc2F_{c2}, i.e. (Fc2−Fc1Fc1)×100\left(\dfrac{F_{c2}-F_{c1}}{F_{c1}}\right)\times100, is ____________ (round off to one decimal place).

Answer (official key): -5.8 to -5.5

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

Q54 · Manufacturing Engineering · Numerical · 2 marks

There are two identical shaping machines S1_1 and S2_2. In machine S2_2, the width of the workpiece is increased by 10%10\% and the feed is decreased by 10%10\%, with respect to that of S1_1. If all other conditions remain the same then the ratio of total time per pass in S1_1 and S2_2 will be ____________ (round off to one decimal place).

Answer (official key): 0.7 to 0.9

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

Q55 · Manufacturing Engineering · Numerical · 2 marks

Bars of 250250 mm length and 2525 mm diameter are to be turned on a lathe with a feed of 0.20.2 mm/rev. Each regrinding of the tool costs Rs. 2020. The time required for each tool change is 11 min. Tool life equation is given as VT0.2=24VT^{0.2}=24 (where cutting speed VV is in m/min and tool life TT is in min). The optimum tool cost per piece for maximum production rate is Rs. ____________ (round off to 2 decimal places).

Answer (official key): 26 to 28

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

Q56 · Manufacturing Engineering · Numerical · 2 marks

A point ‘P’ on a CNC controlled XY-stage is moved to another point ‘Q’ using the coordinate system shown in the figure below and rapid positioning command (G00).

Figure for GATE 2020 ME (Set 2) question 56 (Manufacturing Engineering)

A pair of stepping motors with maximum speed of 800800 rpm, controlling both the X and Y motion of the stage, are directly coupled to a pair of lead screws, each with a uniform pitch of 0.50.5 mm. The time needed to position the point ‘P’ to the point ‘Q’ is ____________ minutes (round off to 2 decimal places).

Answer (official key): 1.4 to 1.6

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

Q57 · Industrial Engineering · Numerical · 2 marks

For a single item inventory system, the demand is continuous, which is 1000010000 per year. The replenishment is instantaneous and backorders (SS units) per cycle are allowed as shown in the figure.

Figure for GATE 2020 ME (Set 2) question 57 (Industrial Engineering)

As soon as the quantity (QQ units) ordered from the supplier is received, the backordered quantity is issued to the customers. The ordering cost is Rs. 300300 per order. The carrying cost is Rs. 44 per unit per year. The cost of backordering is Rs. 2525 per unit per year. Based on the total cost minimization criteria, the maximum inventory reached in the system is ______ (round off to nearest integer).

Answer (official key): 1130 to 1140

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

Q58 · Fluid Mechanics · Numerical · 2 marks

Consider a flow through a nozzle, as shown in the figure below.

Figure for GATE 2020 ME (Set 2) question 58 (Fluid Mechanics)

The air flow is steady, incompressible and inviscid. The density of air is 1.231.23 kg/m3^3. The pressure difference, (p1−patm)(p_1-p_{atm}) is ____________ kPa (round off to 2 decimal places).

Answer (official key): 1.5 to 1.55

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

Q59 · Fluid Mechanics · Numerical · 2 marks

Water (density 10001000 kg/m3^3) flows through an inclined pipe of uniform diameter. The velocity, pressure and elevation at section A are VA=3.2V_A=3.2 m/s, pA=186p_A=186 kPa and zA=24.5z_A=24.5 m, respectively, and those at section B are VB=3.2V_B=3.2 m/s, pB=260p_B=260 kPa and zB=9.1z_B=9.1 m, respectively. If acceleration due to gravity is 1010 m/s2^2 then the head lost due to friction is ______________ m (round off to one decimal place).

Answer (official key): 7.9 to 8.1

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

Q60 · Heat Transfer · Numerical · 2 marks

The spectral distribution of radiation from a black body at T1=3000T_1=3000 K has a maximum at wavelength λmax⁡\lambda_{\max}. The body cools down to a temperature T2T_2. If the wavelength corresponding to the maximum of the spectral distribution at T2T_2 is 1.21.2 times of the original wavelength λmax⁡\lambda_{\max}, then the temperature T2T_2 is ______________ K (round off to the nearest integer).

Answer (official key): 2499 to 2501

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

Q61 · Heat Transfer · Numerical · 2 marks

Water flows through a tube of 33 cm internal diameter and length 2020 m. The outside surface of the tube is heated electrically so that it is subjected to uniform heat flux circumferentially and axially. The mean inlet and exit temperatures of the water are 10∘C10^\circ\mathrm{C} and 70∘C70^\circ\mathrm{C}, respectively. The mass flow rate of the water is 720720 kg/h. Disregard the thermal resistance of the tube wall. The internal heat transfer coefficient is 16971697 W/m2^2.K. Take specific heat CpC_p of water as 4.1794.179 kJ/kg.K. The inner surface temperature at the exit section of the tube is ____________ ∘C^\circ\mathrm{C} (round off to one decimal place).

Answer (official key): 85.1 to 86.1

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

Q62 · Thermodynamics · Numerical · 2 marks

Air is contained in a frictionless piston-cylinder arrangement as shown in the figure.

Figure for GATE 2020 ME (Set 2) question 62 (Thermodynamics)

The atmospheric pressure is 100100 kPa and the initial pressure of air in the cylinder is 105105 kPa. The area of piston is 300300 cm2^2. Heat is now added and the piston moves slowly from its initial position until it reaches the stops. The spring constant of the linear spring is 12.512.5 N/mm. Considering the air inside the cylinder as the system, the work interaction is _______ J (round off to the nearest integer).

Answer (official key): 543 to 545

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

Q63 · Thermal Applications · Numerical · 2 marks

Moist air at 105105 kPa, 30∘C30^\circ\mathrm{C} and 80%80\% relative humidity flows over a cooling coil in an insulated air-conditioning duct. Saturated air exits the duct at 100100 kPa and 15∘C15^\circ\mathrm{C}. The saturation pressures of water at 30∘C30^\circ\mathrm{C} and 15∘C15^\circ\mathrm{C} are 4.244.24 kPa and 1.71.7 kPa respectively. Molecular weight of water is 1818 g/mol and that of air is 28.9428.94 g/mol. The mass of water condensing out from the duct is _______ g/kg of dry air (round off to the nearest integer).

Answer (official key): 10

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

Q64 · Thermal Applications · Numerical · 2 marks

In a steam power plant, superheated steam at 1010 MPa and 500∘C500^\circ\mathrm{C} is expanded isentropically in a turbine until it becomes a saturated vapour. It is then reheated at constant pressure to 500∘C500^\circ\mathrm{C}. The steam is next expanded isentropically in another turbine until it reaches the condenser pressure of 2020 kPa. Relevant properties of steam are given in the following two tables. The work done by both the turbines together is _______ kJ/kg (round off to the nearest integer).

Superheated Steam Table:

Pressure, pp (MPa)Temperature, TT (∘C^\circ\mathrm{C})Enthalpy, hh (kJ/kg)Entropy, ss (kJ/kg.K)
10105005003373.63373.66.59656.5965
115005003478.43478.47.76217.7621

Saturated Steam Table:

Pressure, ppSat. Temp., TsatT_{sat} (∘C^\circ\mathrm{C})Enthalpy hfh_f (kJ/kg)Enthalpy hgh_g (kJ/kg)Entropy sfs_f (kJ/kg.K)Entropy sgs_g (kJ/kg.K)
11 MPa179.91179.91762.9762.92778.12778.12.13862.13866.59656.5965
2020 kPa60.0660.06251.38251.382609.72609.70.83190.83197.90857.9085

Answer (official key): 1500 to 1525

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

Q65 · Thermodynamics · Numerical · 2 marks

Keeping all other parameters identical, the Compression Ratio (CR) of an air standard diesel cycle is increased from 1515 to 2121. Take ratio of specific heats =1.3=1.3 and cut-off ratio of the cycle rc=2r_c=2.

The difference between the new and the old efficiency values, in percentage,

(ηnew∣CR=21)−(ηold∣CR=15)=(\eta_{new}|_{CR=21})-(\eta_{old}|_{CR=15})= __________ %\% (round off to one decimal place).

Answer (official key): 4.6 to 4.9

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