GATE 2021 ME (Set 2) question paper PDF and answer key

The official GATE 2021 Mechanical Engineering (Set 2) paper, organised by IIT Bombay: 65 questions for 100 marks in 3 hours. Download the official question paper and answer key as PDFs. Below is how the marks were split by topic, the complete official answer key and 5 questions solved step by step.

Source: the official paper and answer key published by IIT Bombay for GATE 2021 (official GATE site). Spotted a mistake? Email team@lemyte.com.

General Aptitude
10 · 15 marks
Mechanical Engineering
55 · 85 marks
MCQ / MSQ / NAT
38 / 0 / 27
Marks to all
None

Where the marks were

GATE 2021 ME (Set 2) topic-wise marks

Mechanical Engineering questions only; General Aptitude adds 15 marks on top. The top three topics carried 33 of the 85 subject marks.

TopicQuestionsMarks
Manufacturing Engineering1016
Fluid Mechanics710
Industrial Engineering47
Mechanics of Materials57
Theory of Machines46
Heat Transfer35
Applied Mechanics35
Thermal Applications35
Thermodynamics34
Vibrations24
Linear Algebra23
Differential Equations23
Numerical Methods23
Calculus12
Machine Design12
Probability and Statistics11
Engineering Materials11
Complex Variables11

Free solved questions

5 solved questions from GATE 2021 ME (Set 2)

Question text and figures as in the official paper, the answer from the official key, and a worked solution. The other 60 solutions are in your report after you take the paper.

Q1 · General Aptitude · MCQ · 1 mark

Five persons P, Q, R, S and T are to be seated in a row, all facing the same direction, but not necessarily in the same order. P and T cannot be seated at either end of the row. P should not be seated adjacent to S. R is to be seated at the second position from the left end of the row. The number of distinct seating arrangements possible is:

  • (A)
    22
  • (B)
    33
  • (C)
    44
  • (D)
    55

Answer (official key): B

Solution

R occupies position 2, so P and T must occupy positions 3 and 4. Applying the restriction that P cannot sit next to S gives the arrangements QRPTS, SRPTQ and SRTPQ. Thus there are 33 arrangements, option B.

Q4 · General Aptitude · MCQ · 1 mark

If ⊕÷⊙=2\oplus\div\odot=2; ⊕÷Δ=3\oplus\div\Delta=3; ⊙+Δ=5\odot+\Delta=5; Δ×⊗=10\Delta\times\otimes=10,

Then, the value of (⊗−⊕)2(\otimes-\oplus)^2, is:

  • (A)
    00
  • (B)
    11
  • (C)
    44
  • (D)
    1616

Answer (official key): B

Solution

Let the values represented by ⊕,⊙,Δ,⊗\oplus,\odot,\Delta,\otimes be a,b,c,da,b,c,d. Then a=2b=3ca=2b=3c and b+c=5b+c=5, giving c=2c=2, b=3b=3 and a=6a=6. Since cd=10cd=10, d=5d=5. Thus (d−a)2=(5−6)2=1(d-a)^2=(5-6)^2=1, option B.

Q42 · Theory of Machines · MCQ · 2 marks

A power transmission mechanism consists of a belt drive and a gear train as shown in the figure.

Figure for GATE 2021 ME (Set 2) question 42 (Theory of Machines)

Diameters of pulleys of belt drive and number of teeth (TT) on the gears 22 to 77 are indicated in the figure. The speed and direction of rotation of gear 77, respectively, are

  • (A)
    255.68255.68 rpm; clockwise
  • (B)
    255.68255.68 rpm; anticlockwise
  • (C)
    575.28575.28 rpm; clockwise
  • (D)
    575.28575.28 rpm; anticlockwise

Answer (official key): A

Solution

The belt gives N2=2500(150/250)=1500N_2=2500(150/250)=1500 rpm. Gears 33 and 44 share a shaft, as do 66 and 77; gear 55 is an idler. Thus N7=1500(18/44)(15/36)=255.68N_7=1500(18/44)(15/36)=255.68 rpm. The open belt preserves direction, and the three external gear meshes reverse it overall, giving clockwise rotation. Hence A.

Q43 · Vibrations · MCQ · 2 marks

A machine of mass 100100 kg is subjected to an external harmonic force with a frequency of 4040 rad/s. The designer decides to mount the machine on an isolator to reduce the force transmitted to the foundation. The isolator can be considered as a combination of stiffness (KK) and damper (damping factor, ξ\xi) in parallel. The designer has the following four isolators:

  1. K=640K=640 kN/m, ξ=0.70\xi=0.70

  2. K=640K=640 kN/m, ξ=0.07\xi=0.07

  3. K=22.5K=22.5 kN/m, ξ=0.70\xi=0.70

  4. K=22.5K=22.5 kN/m, ξ=0.07\xi=0.07

Arrange the isolators in the ascending order of the force transmitted to the foundation.

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

Answer (official key): C

Solution

Force transmissibility is TR=[1+(2ξr)2]/[(1−r2)2+(2ξr)2]T_R=\sqrt{[1+(2\xi r)^2]/[(1-r^2)^2+(2\xi r)^2]}, where r=ω/K/mr=\omega/\sqrt{K/m}. The frequency ratios are 0.50.5 for isolators 1 and 2, and 8/38/3 for 3 and 4. Their transmissibilities are approximately 1.1901.190, 1.3311.331, 0.5400.540, and 0.1740.174, respectively. The ascending order is 4-3-1-2, so C.

Q45 · Numerical Methods · Numerical · 2 marks

Find the positive real root of x3−x−3=0x^3-x-3=0 using Newton-Raphson method. If the starting guess (x0x_0) is 22, the numerical value of the root after two iterations (x2x_2) is _____________ (round off to two decimal places).

Answer (official key): 1.66 to 1.68

Solution

Newton-Raphson gives xn+1=xn−(xn3−xn−3)/(3xn2−1)x_{n+1}=x_n-(x_n^3-x_n-3)/(3x_n^2-1). Starting at x0=2x_0=2, x1=2−3/11=1.72727x_1=2-3/11=1.72727 and x2≈1.67369x_2\approx1.67369. After two iterations, the answer is 1.671.67.

The other 60 questions are solved in your report when you take GATE 2021 ME (Set 2) as a 3-hour test.

Take GATE 2021 ME (Set 2) as a test

Official answer key

GATE 2021 ME (Set 2) answer key

All 65 answers from the official key. Numerical answers are ranges; “or” means the key accepts either answer.

Download the official GATE 2021 ME (Set 2) answer key (PDF)
QTopicTypeMarksAnswer
1Analytical AptitudeMCQ1B
2Verbal AptitudeMCQ1A
3Quantitative AptitudeMCQ1A
4Quantitative AptitudeMCQ1B
5Spatial AptitudeMCQ1D
6Analytical AptitudeMCQ2C
7Quantitative AptitudeMCQ2B
8Quantitative AptitudeMCQ2C
9Spatial AptitudeMCQ2B
10Verbal AptitudeMCQ2D
11Linear AlgebraMCQ1D
12Differential EquationsMCQ1C
13Probability and StatisticsMCQ1D
14Engineering MaterialsMCQ1D
15Manufacturing EngineeringMCQ1A
16Manufacturing EngineeringMCQ1D
17Manufacturing EngineeringMCQ1D
18Industrial EngineeringMCQ1B
19Manufacturing EngineeringMCQ1C
20Heat TransferMCQ1A
21Fluid MechanicsMCQ1D
22Fluid MechanicsMCQ1B
23Fluid MechanicsMCQ1B
24Applied MechanicsMCQ1B
25Theory of MachinesMCQ1D
26Theory of MachinesMCQ1B
27Mechanics of MaterialsMCQ1D
28Numerical MethodsMCQ1A
29Complex VariablesMCQ1B
30ThermodynamicsNumerical1373 to 377
31Thermal ApplicationsNumerical1165
32ThermodynamicsNumerical1134 to 136
33Fluid MechanicsNumerical1228 to 230
34Mechanics of MaterialsNumerical1800 to 840
35Mechanics of MaterialsNumerical10.08 to 0.12
36CalculusMCQ2B
37Linear AlgebraMCQ2B
38Differential EquationsMCQ2C
39Industrial EngineeringMCQ2A
40Thermal ApplicationsMCQ2D
41Mechanics of MaterialsMCQ2B
42Theory of MachinesMCQ2A
43VibrationsMCQ2C
44VibrationsMCQ2B
45Numerical MethodsNumerical21.66 to 1.68
46Industrial EngineeringNumerical240200 to 40300
47Manufacturing EngineeringNumerical22.6 to 3
48Manufacturing EngineeringNumerical239 to 40
49Manufacturing EngineeringNumerical238 to 39
50Manufacturing EngineeringNumerical2388 to 400
51Manufacturing EngineeringNumerical23880 to 3886
52Manufacturing EngineeringNumerical2200 to 206
53Industrial EngineeringNumerical26 to 10
54Heat TransferNumerical2337 to 341
55Heat TransferNumerical210
56Fluid MechanicsNumerical22257 to 2259
57Thermal ApplicationsNumerical225 to 25.4
58Fluid MechanicsNumerical2130 to 134
59Fluid MechanicsNumerical290 to 92
60ThermodynamicsNumerical22.1 to 2.3
61Applied MechanicsNumerical20.16 to 0.19
62Applied MechanicsNumerical21.3 to 1.4
63Mechanics of MaterialsNumerical248 to 52
64Theory of MachinesNumerical2560 to 580
65Machine DesignNumerical2152000 to 165000

Questions about GATE 2021 ME (Set 2)

How many questions are in the GATE 2021 ME (Set 2) paper?

65 questions for 100 marks: 10 General Aptitude questions worth 15 marks and 55 Mechanical Engineering questions worth 85 marks. By type, there were 38 MCQs, 27 numerical answer (NAT) questions. The paper lasted 3 hours.

Is there negative marking in GATE 2021 ME (Set 2)?

Yes, for MCQs only. A wrong MCQ answer costs one-third of its marks (−⅓ for a 1-mark question, −⅔ for a 2-mark question). MSQ and numerical (NAT) questions have no negative marking, and an MSQ earns marks only when every correct option is chosen.

Which topics carried the most marks in GATE 2021 ME (Set 2)?

Outside General Aptitude, the biggest topics were Manufacturing Engineering (16 marks), Fluid Mechanics (10 marks), Industrial Engineering (7 marks). The full topic-wise split is in the table on this page.

Were any GATE 2021 ME (Set 2) questions awarded marks to all?

No. Every question was graded with the answer in the official key.

Where does this GATE 2021 ME (Set 2) answer key come from?

From the official answer key published by IIT Bombay, which organised GATE 2021. Range answers for numerical questions and questions with more than one accepted answer are kept exactly as the key gives them.

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