Material Science - Structure of Materials
Exam Duration: 45 Mins Total Questions : 30
Match List I (Name of material) with List II (Percentagecarbon range) and select the correct answer using the codes given below the lists.
List I | List II |
P.Hypoeutectoid steel | 1. 4.3-6.67 |
Q.Hypereutectoid steel | 2. 2.0-4.3 |
R.Hypoeutectic cast iron | 3. 0.8-2.0 |
S.Hypereutectic cast iron | 4. 0.008-0.8 |
Codes
- (a)
P Q R S 4 3 2 1 - (b)
P Q R S 1 3 4 2 - (c)
P Q R S 4 1 2 3 - (d)
P Q R S 1 2 3 4
Guideways of lathe beds are hardened by
- (a)
carburizing
- (b)
cyaniding
- (c)
nitriding
- (d)
flame hardening
A given steel test specimen is studied under metallurgical microscope. Magnification used is 100 X. In that different phases are observed. One of them is Fe3C. The observed phase Fe3C is also known as
- (a)
ferrite
- (b)
cementite
- (c)
austenite
- (d)
martensite
Two cooling curves A and B for eutectoid iron-carbon alloy are superimposed on a continuous coolingtransformation diagram as shown in the given figure. Fine pearlite microstructure is represented by the points labelled.
- (a)
I and III
- (b)
Only II
- (c)
Only IV
- (d)
Only I
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
Monel metal is an alloy of
- (a)
iron and carbon
- (b)
copper and zinc
- (c)
aluminium and copper
- (d)
copper and nickel
Globular form of cementite in the structure of steel is obtained through
- (a)
normalising
- (b)
malleabilising
- (c)
spheroidising
- (d)
carbonizing
Which one of the following pairs is not correctly matched?
- (a)
Point defect in crystal lattice:Self interstitial
- (b)
Linear defect in crystal lattice:Grain boundary
- (c)
Planar defect in crystal lattice:External surface
- (d)
Volume defect in crystal lattice:Other phases
Match List I (Alloying element) with List II (Effect on steel) and select the correct answer using the codes given below the lists.
List I | List II |
P.Vanadium | 1.Increases endurance strength |
Q.Molybdenum | 2.Improves creep properties |
R.Silicon | 3.Increases hardness |
S.Chromium | 4.Increases resistance to high temperature oxidation |
Codes
- (a)
P Q R S 2 1 3 4 - (b)
P Q R S 1 3 2 4 - (c)
P Q R S 2 1 4 3 - (d)
P Q R S 1 2 4 3
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
Miller indices [x, y, z] for the hatched plane in the below unit cell are represented as
- (a)
[1 0 0]
- (b)
[1 1 0]
- (c)
[1 1 1]
- (d)
[1 0 1]
Iron-carbon equilibrium diagram
- (a)
correlates the microstructure and properties of steel and cast iron
- (b)
indicates the phase changes occurring during heating and cooling
- (c)
is made by plotting carbon percentage along X-axis and temperature along Y-axis
- (d)
All of the above
Miller indices <hkl> denotes
- (a)
family of direction
- (b)
direction
- (c)
plane
- (d)
None of these
Which of the following is correct statement?
- (a)
Characteristic of any series of alloy cannot be found as phase diagram
- (b)
Phase diagram does not give amount of phases which are function of composition, temperature and pressure
- (c)
The phase may be liquid or vapour with ordered crystal structure
- (d)
Phase diagram provides the information on how rapidly equilibrium is reached.
Which of the following is correct statement?
- (a)
Characteristic of any series of alloy cannot be found as phase diagram
- (b)
Phase diagram does not give amount of phases which are function of composition, temperature and pressure
- (c)
The phase may be liquid or vapour with ordered crystal structure
- (d)
Phase diagram provides the information on how rapidly equilibrium is reached.
Pearlite consists of
- (a)
6.67% C and 93.33 ferrite
- (b)
12% Fe and 87% cementite
- (c)
13% C and 87% ferrite
- (d)
l3% cementite and 87% ferrite
Addition of vanadium to steel results in improvement of
- (a)
heat-treatability by quenching
- (b)
harden ability
- (c)
fatigue strength
- (d)
resistance to oxidation at elevated temperature
During peritectic solidification, one liquid
- (a)
combines with one solid to form a second new solid
- (b)
solidifies into two different solids
- (c)
forms one solid
- (d)
forms one solid and another liquid
Martensite is a supersaturated solution of carbon in
- (a)
alpha iron
- (b)
beta iron
- (c)
gamma iron
- (d)
delta iron
Which one of the following pairs of axis lengths (a, b, c) and interaxial angles \((\alpha ,\beta ,\Upsilon )\)represents the tetragonal crystal system?
- (a)
\(a=b=c;\alpha =\beta =\Upsilon ={ 90 }^{ o }\)
- (b)
\(a=b\neq c;\alpha =\beta =\Upsilon ={ 90 }^{ o }\)
- (c)
\(a\neq b\neq c;\alpha =\beta =\Upsilon ={ 90 }^{ o }\)
- (d)
\(a=b=c;\alpha =\beta =\Upsilon \neq { 90 }^{ o }\)
TTT diagram indicates time, temperature and transformation of
- (a)
cementite
- (b)
pearlite
- (c)
ferrite
- (d)
austenite
Consider the following statements about FCC and HCP crystal structures:
I. Both have same coordination number and atomic packing fraction.
2. Both represent closely packed crystal structures.
3. Both structures are generated by stacking of close packed planes on top of one another but only the stacking sequence is different.
Which of these statements are correct?
- (a)
1 and 2
- (b)
2 and 3
- (c)
1,2 and 3
- (d)
1 and 3
Consider the following statements:
1. Cast iron has poor ability to damp vibrations.
2. Cast iron has higher compressive strength compared to that of steel.
3. Cast iron parts are suitable where permanent deformation is preferred over fracture.
Which of these statements is/are correct?
- (a)
1,2 and 3
- (b)
1 and 3
- (c)
only 3
- (d)
only 2
The main purpose of spheroidising treatment is to improve
- (a)
harden ability of low carbon steels
- (b)
machinability of low carbon steels
- (c)
harden ability of high carbon steels
- (d)
machinability of high carbon steels
The effective number of lattice points in the unit cell of simple cubic, body centred cubic and face centered cubic space lattices respectively, are
- (a)
1,2 and 2
- (b)
1,2 and 4
- (c)
2, 3 and 4
- (d)
2, 4 and 4