Structure of Materials
Exam Duration: 45 Mins Total Questions : 30
In low carbon steels, presence of small sulphur quantity improves
- (a)
weldability
- (b)
formability
- (c)
mechinability
- (d)
harden ability
Machine tools guideways are usually hardness by
- (a)
vacuum hardening
- (b)
martempering
- (c)
induction hardening
- (d)
flame hardening
Match List I (Alloys) with List II (Applications) and select the correct answer using the codes given below the lists.
List I | List II |
P.Chromel | 1Journal bearing. |
Q.Babbit alloy | 2.Milling cutter |
R.Nimonic alloy | 3.Thermocouple wire |
S.High speed steel | 4.Gas turbine blades |
Codes
- (a)
P Q R S 3 1 4 2 - (b)
P Q R S 3 4 1 2 - (c)
P Q R S 2 4 1 3 - (d)
P Q R S 2 1 4 3
The set of Miller indices of the plane shown in the given figure is
- (a)
[1 0 0]
- (b)
\([ { 1 } \ 0\ 0]\)
- (c)
[1 0 1]
- (d)
[1 1 0]
Match List I (Material) with List II (Applications) and select the correct answer using the codes given below the lists.
List I | List II |
P.Tungsten carbide | 1.Abrasive wheels |
Q.Silicon nitrid | 2.Heating elements |
R.Aluminium oxide | 3.Pipes for conveying liquid metals |
S.Silicon carbide | 4.Drawing dies |
Codes
- (a)
P Q R S 3 4 1 2 - (b)
P Q R S 4 3 2 1 - (c)
P Q R S 3 4 2 1 - (d)
P Q R S 4 3 1 2
The molecular weight of vinyl chloride is 62.5. Thus, the molecular weight of a polyvinyl chloride with a degree of polymerization of 20000 is
- (a)
\(\frac { 20000 }{ 62.5 } \)
- (b)
\(\frac { 62.5 }{ 20000 } \)
- (c)
62.5 x 20000
- (d)
20000
Primary object of full annealing is to
- (a)
increase toughness and yield point
- (b)
reduce ductility and resilience
- (c)
remove foreign impurities and improve surface finish
- (d)
increase ductility and mechinability
Gun metal, which is used in journal bearings, contains
- (a)
88% Cu, 1O% Sn, 2% Zn
- (b)
80% Cu, 1O% Zn, 10% Al
- (c)
85% Cu, 5% Mg, 1O% Al
- (d)
85% Cu, 5% Sn, 10% Pb
Match List I (Fe-Fe3C phase diagram characteristic) with List II (Phase) and select the correct answer using the codes given below the lists.
List I | List II |
P.Alpha (\(\alpha \)) iron | 1.\(\delta \) iron |
Q.Iron carbide having crystal lattice |
2.Eutectic with 3 iron and 1 carbon atom |
R.BCC pure allotrope of iron is stable between 1388°C and its melting point at 1535°C |
3.Ferrite stable between 1388°C |
Cementite |
Codes
- (a)
P Q R 4 2 3 - (b)
P Q R 3 4 1 - (c)
P Q R 4 2 1 - (d)
P Q R 3 1 2
Which one of the following is correct for Burger's vector in screw dislocation?
- (a)
Perpendicular to the dislocation line
- (b)
Inclined to the dislocation line
- (c)
Parallel to the dislocation line
- (d)
Opposite to the dislocation line
Which one of the following defects is 'Schottky defect'?
- (a)
Vacancy defect
- (b)
Compositional defect
- (c)
Interstitial defect
- (d)
Surface defect
Which one of the following elements is an austenitic stabilizer?
- (a)
Chromium
- (b)
Tungsten
- (c)
Nickel
- (d)
Molybdenum
The elements which added to steel, help in chip formation during machining are
- (a)
sulphur, lead and phosphorous
- (b)
sulphur, lead and cobalt
- (c)
aluminium, lead and copper
- (d)
aluminium, titanium and copper
The hardness of lathe bed material should be measured by
- (a)
rockwell tester
- (b)
brinell hardness tester
- (c)
shore scleroscope
- (d)
vickers hardness tester
Consider the following statements regarding annealing process:
1. All structural imperfections are removed.
2. The hypoeutectoid steel is heated around 50-70°C below upper critical temperature ...
3. Cooling can be done in heat treating furnace, by heating it, keeping the metal in it and turning off
furnace till it cools to room temperature.
4. Uniform grain structure is resulted?
Which of these statements are correct?
- (a)
1,2 and 3
- (b)
2,3 and 4
- (c)
1, 3 and 4
- (d)
1, 2, 3 and 4
Match List I (Name of the invariant reaction) with List II (Critical load reaction during cooling) and select the correct answer using the codes given below the lists.
List I | List II |
P.Monotectic | 1.LIQUID \(\rightarrow \) SOLID1 + SOLID2 |
Q.Eutectic | 2.LIQUID1\(\rightarrow \) LIQUID2 + SOLID |
R.Eutectoid | 3.SOLID \(\rightarrow \) SOLID1 + SOLID2 |
S.Peritectic | 4.LIQUID + SOLID1 \(\rightarrow \) SOLID2 |
Codes
- (a)
P Q R S 3 1 2 4 - (b)
P Q R S 2 4 3 1 - (c)
P Q R S 3 4 2 1 - (d)
P Q R S 2 1 3 4
Which process gives extreme hardness to surface?
- (a)
Nitriding
- (b)
Carburizing
- (c)
Cyaniding
- (d)
Hardening
Ferrites are
- (a)
antimagnetic
- (b)
ferromagnetic
- (c)
paramagnetic
- (d)
None of these
Match the List I with List II and choose the most appropriate set of heat treatment process with the corresponding process characteristics and find the correct answer using the codes given below the lists.
List I (Process) | List II (Characteristics) | ||
---|---|---|---|
P. | Tempering | 1. | Austenite is converted into bainite |
Q. | Austempering | 2. | Austenite is converted into martensite |
R. | Martempering | 3. | Cementite is converted into globular structure |
4. | Both hardness and brittleness are reduced | ||
5. | Carbon is absorbed into the metal |
- (a)
Codes P Q R 3 1 5 - (b)
Codes P Q R 4 3 2 - (c)
Codes P Q R 4 1 2 - (d)
Codes P Q R 1 5 4
Consider the following statements: Alloying elements are added to
1. improve hardness and toughness.
2. corrosion and oxidation resistance improvement.
3. improve machinability and hardenabililty.
4. increase weight and volume.
Which of these statements are correct?
- (a)
1,2 and 3
- (b)
2,3 and 4
- (c)
1,2 and 4
- (d)
1,2,3 and 4
Surface imperfections, which separate two orientations that are mirror image of one another is called
- (a)
stacking fault
- (b)
grain boundary
- (c)
tit boundary
- (d)
twinned boundary
Isothermal annealing is mainly used in alloy steels to improve
- (a)
mechinability
- (b)
toughness
- (c)
ductility
- (d)
weldability
Atomic Packing Factor (APF) in the case of copper crystal is
- (a)
0.52
- (b)
0.68
- (c)
0.74
- (d)
1.633
The correct sequence of creep deformation in a creep curve in order of their elongation is
- (a)
steady state, transient and accelerated
- (b)
transient, steady state and accelerated
- (c)
transient, accelerated and steady state
- (d)
accelerated, steady state and transient
Nodular grey cast iron is obtained from the grey cast iron by adding a small amount of
- (a)
manganese
- (b)
phosphorus
- (c)
magnesium
- (d)
chromium
Consider the following quenching media
1. Oil 2. Water
3. Water + NaOH 4. Brine
The correct sequence of these media in order of increasing hardness of steel undergoing heat treatment is
- (a)
1,3,2 and 4
- (b)
2, 1,3 and 4
- (c)
1,2, 3 and 4
- (d)
4,3,2 and 1
TTT diagram indicates time, temperature and transformation of
- (a)
cementite
- (b)
pearlite
- (c)
ferrite
- (d)
austenite
A screw dislocation
1. lies parallel to its Burger's vector.
2. lies perpendicular to its Burger's vector.
3. moves in a perpendicular direction to the Burger's vector.
4. moves in an inclined direction to the Burger's vector.
- (a)
1 and 4
- (b)
1 and 3
- (c)
2 and 3
- (d)
2 and 4
Match List I (Name of treatment) with List II(Media used) and select the correct answer using the codes given below the lists
List I | List II |
P.Pack carburizing | 1.Ammonia gas |
Q.Gas carburizing | 2.Sodium cyanide |
R.Cyaniding | 3.Carburizing compound |
S.Nitriding | 4.Ethane |
Codes
- (a)
P Q R S 3 4 2 1 - (b)
P Q R S 2 1 3 4 - (c)
P Q R S 3 1 2 4 - (d)
P Q R S 2 4 3 1
What is the planar density of [100] plane in FCC (Face Centred Cubic) crystal with unit cell side a?
- (a)
\(\frac { 1.484 }{ { a }^{ 2 } } \)
- (b)
\(\frac { 2 }{ { a }^{ 2 } } \)
- (c)
\(\frac {1 }{ { a }^{ 2 } } \)
- (d)
\(\frac { \sqrt { 2 } }{ { a }^{ 2 } } \)