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GATE 2017-2018 Metallurgical
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1. A is a 2 * 2 matrix with det A = 2. The det (2A) is
4
8
32
16
2. In a production facility, iron rods are made with a mean diameter of 6 cm and standard deviation of 0.02 cm. If a large number of rods are tested, the approximate percentage of rods whose sizes fall in the range of 5.98 cm to 6.02 cm is
68
75
90
99.7
3. Which one of the following methods is NOT used for numerical integration? A. Rectangular ruleB. Trapezoidal ruleC. Simpson's ruleD. Cramer's rule
Rectangular rule
Trapezoidal rule
Simpson's rule
Cramer's rule
4. When a zinc metal rod is immersed in dilute hydrochloric acid, it results in
Evolution of hydrogen
Evolution of chlorine
Evolution of oxygen
No evolution of any gas
5. A fluid is flowing with a velocity of 0.5 m/s on a plate moving with a velocity of 0.01 m/s in the same direction. The velocity at the interface of the fluid and plate is
0.0 m/s
0.01 m/s
0.255 m/s
0.50 m/s
6. Hot metal at 1700 K is poured in a sand mould that is open at the top. Heat loss from the liquid metal takes place by
Radiation only
Radiation and conduction only
Radiation and convection only
Radiation, conduction and convection
7. Which one of the following is an equilibrium defect?
Vacancies
Dislocations
Stacking faults
Grain boundaries
8. Floatation beneficiation is based on the principle of
Mineral surface hydrophobicity
Gravity difference
Chemical reactivity
Particle size difference
9. Copper can be reduced from acidic copper sulphate solution by
Silver
Iron
Carbon
Lead
10. Which one is NOT an agglomeration process?
Nodulizing
Briquetting
Roasting
Pelletizing
11. During LD blow in steelmaking the impurity that gets removed first is
Carbon
Phosphorous
Manganese
Silicon
12. During the solidification of a pure metal, it was found that dendrites are formed. Assuming that the liquid-solid interface is at the melting temperature, the temperature from the interface into the liquid
Decreases
Increases
Remains constant
Increases and then decreases
13. A peak in the X-ray diffraction pattern is observed at 2θ = 78o, corresponding to {311} planes of an fcc metal, when the incident beam has a wavelength of 0.154 nm. The lattice parameter of the metal is approximately
0.6 nm
0.4 nm
0.3 nm
0.2 nm
14. If d is the inter-planar spacing of the planes {h k l}, the inter-planar spacing of the planes {nh nk nl}, n being an integer, is
d
d/n
nd
d/n2
15. As temperature increases, the electrical resistivities of pure metals (Ïm) and intrinsic semiconductors (Ïs) vary as follows
Both Ïm and Ïs increase
Both Ïm and Ïs decrease
Ïm increases and and Ïs decreases
Ïm decreases and and Ïs increases
16. At equilibrium spacing in a crystalline solid, which of the following is true for net inter-atomic force (F) and potential energy (U)
F is zero and U is zero
F is zero and U is minimum
F is minimum and U is zero
F is minimum and U is minimum
17. The property of a material that CANNOT be significantly changed by heat treatment is
Yield strength
Ultimate tensile strength
Ductility
Elastic modulus
18. A polymer matrix composite is reinforced with long continuous ceramic fibres aligned in one direction. The Young's moduli of the matrix and fibres are Em and Ef respectively, and the volume fraction of the fibres is f. Assuming iso-stress condition, Young's modulus of the composite EC in a direction perpendicular to the length of fibres, is given by the expression
EC = (1 - f)Em + fEf
EC = (1 - f)Ef + fEm
1/EC = (1 - f)/Em + f/Ef
1/EC = (1 - f)/Ef + f/Em
19. Which of the following is NOT a fusion welding process?
Arc welding
Gas welding
Resistance welding
Friction stir welding
20. Which of the following is NOT a fusion welding process?
Arc welding
Gas welding
Resistance welding
Friction stir welding
21. The riser is designed such that the melt in the riser solidifies
Before casting solidifies
At the same time as casting solidifies
After casting solidifies
Irrespective of the solidification of the casting
22. Radiography technique of detecting defects is based on the principle of
Diffraction
Reflection
Interference
Absorption
23. At x = 0.5, the polynomial x2(1-x)2 has
No extrema
A saddle point
A minima
A maxima
24. Given that v is a vector field and f is a scalar field, match the equations in Group I with their physical meaning in Group II Group I Group II P. div (v) = 0 1 . I r r otational Q. curl (grad(f)) = 0 2 . Incompressible R. div (grad(f)) = 0 3 . Potential S. v = grad(f) 4 . Laplace equation
P-1, Q-2, R-3, S-4
P-2, Q-1, R-4, S-3
P-1, Q-3, R-2, S-4
P-2, Q-1, R-3, S-4
25. The temperature field of a slab is given by T = 400 - 50z exp(-t - x2 - y2). The temperature gradient in y-direction is
100yz exp(-t - x2 - y2)
-100yz exp(-t - x2 - y2)
100xz exp(-t - x2 - y2)
-100xz exp(-t - x2 - y2)
26. What does the solution of the following ordinary differential equation represent? y dy/dx + x = 0
A parabola
A circle
An ellipse
A hyperbola
27. Match the principles given in Group I with corresponding corrosion terminology in Group II Group I Group II P. Electrode polarization 1. Dezincification Q. Passivity 2. Intergranular attack R. Selective leaching 3. Over voltage S. Grain boundary precipitation 4. Surface oxide film
P-3, Q-4, R-1, S-2
P-3, Q-4, R-2, S-1
P-4, Q-2, R-1, S-3
P-2, Q-1, R-4, S-3
28. Identify the correct combination of the following statements P. Hydrogen electrode is a standard used to measure redox potentials Q. Activation polarization refers to electrochemical processes controlled by reaction sequence at metal-solution interface R. Potential-pH diagrams can be used to predict corrosion rates of metals S. Cathodic protection can use sacrificial anodes such as magnesium
P, Q and R
Q, R and S
P, Q and S
P, R and S
29. Consider a reaction with activation energy of 8.314 kJ/mol that takes place at 300 K. If the reaction rate is to be tripled, the temperature of the reaction should be
174.5 K
447.5 K
600.5 K
847.5 K
30. Match the processes in Group I with the objectives in Group II Group I Group II P. Vacuum Arc Degassing (VAD) 1. Primary iron making Q. LD 2. Secondary steel making R. COREX 3. Direct smelting S. Blast Furnace 4. Primary steel making
P-3, Q-4, R-2, S-1
P-4, Q-3, R-1, S-2
P-3, Q-2, R-1, S-4
P-2, Q-4, R-3, S-1
31. The reduction of FeO with CO gas in co-current flow is given by the following equation: FeO + CO = Fe + CO2 ∆Go = 8120 J at 1173 K The ratio of pCO/pCO2 for this reaction at 1173 K is
0.0
0.25
0.44
2.3
32. The sulphide capacity (CS) of liquid slag of composition 55 wt.% CaO, 20 wt.% SiO2, 5 wt.% Al2O3, and 10 wt.% MgO is given by the following equation log CS = 3.44 (XCaO + 0.1 XMgO - 0.8 XAl2O3 - XSiO2) - (9894/T) + 2.05 where, X is mole fraction of the respective components. Atomic weights of Ca, Mg, Si, Al and O are 40, 24, 28, 27 and 16 respectively. The value of CS at 1900 K is
0.0009
0.009
0.09
0.9
33. Identify the correct combination of the following statements P. Bessemer converter can be used in copper smelting Q. The Mond process for nickel involves reaction of metal with H2 gas R. Roasted ZnS concentrates can be smelted in a blast furnace S. Magnesium metal can be produced by electrolysis of sea water
P, R and S
P, Q and R
P and Q
Q and S
34. Match the phases of steel in Group I with the crystal structures in Group II Group I Group II P. Martensite 1. bcc Q. Cementite 2. fcc R. Austenite 3. bct S. Ferrite 4. Orthorhombic
P-3, Q-4, R-1, S-2
P-2, Q-3, R-1, S-4
P-3, Q-4, R-2, S-1
P-4, Q-3, R-2, S-1
35. Arrange the following in terms of increasing severity of quench P. Oil quenching Q. Water quenching R. Water quenching with agitation S. Brine quenching
P < Q < R < S
Q < R < P < S
C. P < Q < S < R
Q < P < R < S
36. Arrange the following in terms of increasing severity of quench P. Oil quenching Q. Water quenching R. Water quenching with agitation S. Brine quenching
P < Q < R < S
Q < R < P < S
C. P < Q < S < R
Q < P < R < S
37. Regarding recrystallization, which one of the following statements is NOT correct?
Higher the amount of cold work, lower is the recrystallization temperature
Higher the recovery, higher is the recrystallization temperature
Higher the temperature of cold work, higher is the recrystallization temperature
Finer the initial grain size, higher is the recrystallization temperature
38. Match the phenomena listed in Group I with the possible mechanisms in Group II Group I Group II P. Fatigue 1. Grain boundary sliding Q. Creep 2. Slip band extrusion and intrusion R. Strain hardening 3. Cottrell atmosphere S. Yield point phenomenon 4. Dislocation interaction
P-2, Q-3, R-4, S-1
P-2, Q-4, R-3, S-1
P-2, Q-1, R-4, S-3
P-1, Q-2, R-4, S-3
39. Fracture stress for a brittle material having a crack length of 1 μm is 200 MPa. Fracture stress for the same material having a crack length of 4 μm is
200 MPa
150 MPa
100 MPa
50 MPa
40. The flow stress of an alloy varies with strain rate MPa. When the alloy is hot extruded from 10 cm diameter to 5 cm diameter at a speed of 2 cm/s, the flow stress is
1000 MPa
105 MPa
150 MPa
1050 MPa
41. Determine the correctness or otherwise of the following Assertion (a) and Reason (r). Assertion : During rolling, front tension and (or) back tension are (is) employed to decrease rolling load. Reason : Roll pressure decreases due to lowering of flow stress as a result of front tension/back tension.
a is false but r is true
a is true and r is also true, but r is not the reason for a
a is true and r is also true, and r is the reason for a
a is true but r is false
42. Match the defects listed in Group I with the processes listed in Group II Group I Group II P. Cold shut 1. Rolling Q. Earing 2. Forging R. Alligatoring 3. Deep drawing S. Shrinkage porosity 4. Fusion welding
P-2, Q-4, R-1, S-4
P-2, Q-4, R-3, S-1
P-2, Q-3, R-1, S-4
P-4, Q-1, R-2, S-3
43. A steel ball (density Ïsteel = 7200 kg/m3) is placed in an upward moving liquid Al (density ÏAl = 2360 kg/m3, viscosity μAl = 1 * 10“3 Pa.s and Reynolds number = 5 * 105). The force (F) exerted on the steel ball is expressed as F = f Ï€ R2(ÏAl v2/2) where, f is friction factor (=0.2), v is the velocity of liquid Al and R is the radius of steel ball. The force exerted on the steel ball is
8.32 N
6.70 N
1.67 N
0.52 N
44. A material with grain size of ASTM No. 6 has a lattice frictional stress 100 MN/m2 and locking parameter (Hall-Petch constant) 0.10 MN/m3/2 Grain size of the material is approximately
45 μm
35 μm
4.5 μm
3.5 μm
45. A material with grain size of ASTM No. 6 has a lattice frictional stress 100 MN/m2 and locking parameter (Hall-Petch constant) 0.10 MN/m3/2 Yield strength of the material is approximately
100 MPa
115 MPa
165 MPa
215 MPa
46. The strain hardening behaviour of an annealed rod during cold rolling is given by = 700(ε)0.2 MPa, where is the flow stress at strain ε. Flow stress after 50% reduction in area of the annealed rod on cold rolling is approximately
750 MPa
650 MPa
609 MPa
559 MPa
47. Which one of the following options is the closest in meaning to the word given below? Latitude
Eligibility
Freedom
Coercion
Meticulousness
48. Choose the most appropriate word from the options given below to complete the following sentence: Given the seriousness of the situation that he had to face, his ___ was impressive.
beggary
nomenclature
jealousy
nonchalance
49. Choose the most appropriate alternative from the options given below to complete the following sentence: If the tired soldier wanted to lie down, he ___ the mattress out on the balcony.
should take
shall take
should have taken
will have taken
50. One of the parts (A, B, C, D) in the sentence given below contains an ERROR. Which one of the following is INCORRECT? I requested that he should be given the driving test today instead of tomorrow.
requested that
should be given
the driving test
instead of tomorrow
51. If (1.001)1259 = 3.52 and (1.001)2062 = 7.85, then (1.001)3321 =
2.23
4.33
11.37
27.64
52. There are eight bags of rice looking alike, seven of which have equal weight and one is slightly heavier. The weighing balance is of unlimited capacity. Using this balance, the minimum number of weighings required to identify the heavier bag is
2
3
4
8
53. Raju has 14 currency notes in his pocket consisting of only Rs. 20 notes and Rs. 10 notes. The total money value of the notes is Rs. 230. The number of Rs. 10 notes that Raju has is
5
6
9
10
54. One of the legacies of the Roman legions was discipline. In the legions, military law prevailed and discipline was brutal. Discipline on the battlefield kept units obedient, intact and fighting, even when the odds and conditions were against them. Which one of the following statements best sums up the meaning of the above passage?
Thorough regimentation was the main reason for the efficiency of the Roman legions even in adverse circumstances.
The legions were treated inhumanly as if the men were animals.
Discipline was the armies' inheritance from their seniors.
The harsh discipline to which the legions were subjected to led to the odds and conditions being against them.
55. and B are friends. They decide to meet between 1 PM and 2 PM on a given day. There is a condition that whoever arrives first will not wait for the other for more than 15 minutes. The probability that they will meet on that day is
1/4
1/16
7/16
9/16
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