Formation of Ferrite and Cementite from Austenite takes place at:

Temperature = 1130°C, carbon composition = 4.3%

Temperature = 723°C, carbon composition = 2%

Temperature = 1130°C, carbon composition = 0.8%

Temperature = 723°C, carbon composition = 0.8%

Temperature = 1130°C, carbon composition = 4.3%

Directions: It consists of two statements, one labelled as the ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answers to these items using the codes given below:Statement (I):Hard magnetic materials are used for making permanent magnets.Statement (II):Hard magnetic materials have relatively small and narrow hysteresis loop.

Statement (I) is false but Statement (II) is true

Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

Statement (I) is true but Statement (II) is false

Statement (I) is false but Statement (II) is true

A mixture of chemical compounds or elements that have a single chemical composition and solidifies at the lowest temperature than any other composition made up of the same ingredients.

Binary thermally balanced system

Directions: The following items consist of two statements, one labeled as “Statement (I)' and the other as ‘Statement (II)’. You are to examine these two statements carefully and select the answers to these items using the code given below: Statement (I): By organizing various ‘optical functions' into an ‘array structure’ via nano-pattern replication, ‘spatial integration’ is established.Statement (II): By adding a nano-optics layer or layers to functional optical materials, the ‘hybrid integration’ is possible to be achieved.

Statement (I) is true but Statement (II) is false

Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

Statement (I) is true but Statement (II) is false

Statement (I) is false but Statement (II) is true

Ferro-electric material have a

low dielectric constant and is non-linear

high dielectric constant which varies non-linearly

low dielectric constant and is non-linear

high dielectric constant which varies linearly

low dielectric constant but linear

Enameled wires are preferred to cotton-covered wires to

increase the mechanical strength

Direction: It consists of two statements, one labeled as ‘Statement (I)’ and the others as ‘Statement (II)’. You are to examine these two statements carefully and select the answer using the codes given below:Statement (I): Electrostriction occurs due to piezoelectricity which in the reverse effect i.e. the production of polarization on application of mechanical stress if the lattice has no centre of sysmetry.Statement (II): When an electric field is applied to a substance it becomes polarized, the electrons and nuclei assume new geometric positions and the mechanical dimensions of the substance are altered.

Both Statement (I) and Statement (II) are individually true but Statement (II) is NOT the correct explanation of Statement (I)

Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

Both Statement (I) and Statement (II) are individually true but Statement (II) is NOT the correct explanation of Statement (I)

Statement (I) is true but Statement (II) is false

Statement (I) is false but Statement (II) is true

Direction: It consists of two statements, one labelled as ‘Statement (I)’ and the others as ‘Statement (II)’. You are to examine these two statements carefully and select the answer using the codes given below:Statement (I): Mechanically, pearlite has properties intermediate between the soft ductile ferrite and the hard brittle cementite.Statement (II): Alpha iron can be made magnetic above 768° C.

Statement (I) is false, but Statement (II) is true

Both Statement (I) and Statement (II) individually true and Statement (II) is the correct explanation of Statement (I)

Both statement (I) and Statement (II) are individually true, but Statement (II) is not the correct explanation of Statement (I)

Statement (I) is true, but Statement (II) is false

Statement (I) is false, but Statement (II) is true

For applied load P kg, diameter of ball D mm and diameter of indentation d mm, the Brinell hardness number is given by

\({B_{HN}} = \frac{P}{{\frac{\pi }{2}\left( {D - \sqrt {{D^2} - {d^2}} } \right)}}\)

\({B_{HN}} = \frac{D}{{\frac{\pi }{2}\left( {D - \sqrt {{D^2} - {d^2}} } \right)}}\)

\({B_{HN}} = \frac{PD}{{\frac{\pi }{2}\left( {D - \sqrt {{D^2} - {d^2}} } \right)}}\)

\({B_{HN}} = \frac{P}{{(\frac{\pi D }{2})\left( {D - \sqrt {{D^2} - {d^2}} } \right)}}\)

A tube-shaped material made of carbon, having a diameter measuring on the nanometer scale.

A two dimensional material consisting of a single layer of carbon atoms arranged in a honeycomb or chicken wire structure.

A tube-shaped material made of carbon, having a diameter measuring on the nanometer scale.

Completely non-transparent material.

An electrical breakdown of a p-n junction occurs if

forward voltage decreases below the rating

forward voltage increases up to the rating

reverse voltage increases beyond the rating

forward voltage decreases below the rating

reverse voltage decreases below the rating

283 + Mcqs in Structure And Properties Of Engineering Materials in Mechanical Engineering Page 2 McqOptions

51.	Formation of Ferrite and Cementite from Austenite takes place at:
A.	Temperature = 723°C, carbon composition = 2%
B.	Temperature = 1130°C, carbon composition = 0.8%
C.	Temperature = 723°C, carbon composition = 0.8%
D.	Temperature = 1130°C, carbon composition = 4.3%
Answer» D. Temperature = 1130°C, carbon composition = 4.3%

Discussion

52.	Alloy steel containing 36% nickel is called _____.
A.	Invar
B.	Stainless steel
C.	High speed steel
D.	None of these
Answer» B. Stainless steel

Discussion

53.	Dislocations in materials are
A.	Point defect
B.	Surface defect
C.	Planer defect
D.	Line defect
Answer» E.

Discussion

54.	Match the heat treatment processes (Group A) and their associated effects on properties (Group B) of medium carbon steel :Group AGroup BP : TemperingI : Strengthening and grain refinementQ : QuenchingII : Inducing toughnessR : AnnealingIII : HardeningS : NormalizingIV : Softening
A.	P-III, Q-IV, R-II, S-I
B.	P-II, Q-III, R-IV, S-I
C.	P-III, Q-II, R-IV, S-I
D.	P-II, Q-III, R-I, S-IV
Answer» C. P-III, Q-II, R-IV, S-I

Discussion

55.	If a pair of one cation and one anion is missing in an ionic crystal such that those pairs of ions are equal to maintain electrical neutrality, then that pair of vacant sites is called
A.	Schottky imperfection
B.	pair of vacancies
C.	Frenkel defect
D.	Point imperfection
Answer» B. pair of vacancies

Discussion

56.	Mild steel belongs to which of the category?
A.	High carbon steel
B.	Medium carbon steel
C.	Low carbon steel
D.	No carbon steel
Answer» D. No carbon steel

Discussion

57.	Babbit is an alloy of
A.	Sn, Cu, Sb and Pb
B.	Sn and Cu
C.	Sn, Cu and Pb
D.	Sn, Cu and Sb
Answer» B. Sn and Cu

Discussion

58.	Denoting L as liquid and M as solid in a phase-diagram with the subscripts representing different phases, a eutectoid reaction is described by
A.	M1 → M2 + M3
B.	L1 → M1 + M2
C.	L1 + M1 → M2
D.	M1 → M2 + L3
Answer» B. L1 → M1 + M2

Discussion

59.	Directions: It consists of two statements, one labelled as the ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answers to these items using the codes given below:Statement (I):Hard magnetic materials are used for making permanent magnets.Statement (II):Hard magnetic materials have relatively small and narrow hysteresis loop.
A.	Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
B.	Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)
C.	Statement (I) is true but Statement (II) is false
D.	Statement (I) is false but Statement (II) is true
Answer» D. Statement (I) is false but Statement (II) is true

Discussion

60.	_______ is commonly used for making household utensils.
A.	Duralumin
B.	Hindalium
C.	Y - alloy
D.	Magnalium
Answer» C. Y - alloy

Discussion

61.	_________ is present in high percentage in magnet steel.
A.	Aluminium
B.	Tungsten
C.	Zinc
D.	Copper
Answer» C. Zinc

Discussion

62.	In Glass Fiber Reinforced plastic (GFRP) composites with long fibers, the role of matrix is to(P) Support and transfer the stresses to the fibers(Q) Reduced propagation of cracks (R) Carry the entire load(S) Protect the fibers against damageThe correct statements are
A.	P, Q and R
B.	Q, R and S
C.	P, Q and S
D.	P, R and S
Answer» D. P, R and S

Discussion

63.	Consider the following statements:Machine tool beds are made using grey cast iron due to1. high tensile strength and ductility2. high compressive strength and damping property3. castability and low cost of production4. machinability and low material costWhich of the above statements are correct?
A.	1, 2 and 3 only
B.	1, 3 and 4 only
C.	2, 3 and 4 only
D.	1, 2, 3 and 4
Answer» D. 1, 2, 3 and 4

Discussion

64.	Match the items in columns I and II.Column IColumn II(P) Charpy test(1) Fluidity(Q) Knoop test(2) Microhardness(R) Spiral test(3) Formability(S) Cupping test(4) Toughness (5) Permeability
A.	P - 4 Q - 5 R - 3 S - 2
B.	P - 3 Q - 5 R - 1 S - 4
C.	P - 2 Q - 4 R - 3 S – 5
D.	P - 4 Q - 2 R - 1 S - 3
Answer» E.

Discussion

65.	Behaviour of conductors, semiconductors and insulators is explained on the basis of
A.	atomic structure
B.	molecular structure
C.	energy band structure
D.	all of the above
Answer» D. all of the above

Discussion

66.	A mixture of chemical compounds or elements that have a single chemical composition and solidifies at the lowest temperature than any other composition made up of the same ingredients.
A.	Phase balanced system
B.	Eutectic system
C.	Binary thermally balanced system
D.	Intrinsic system
Answer» C. Binary thermally balanced system

Discussion

67.	Cementite has the chemical formula:
A.	Fe4C
B.	Fe2C2
C.	Fe3C
D.	Fe2C
Answer» D. Fe2C

Discussion

68.	Directions: The following items consist of two statements, one labeled as “Statement (I)' and the other as ‘Statement (II)’. You are to examine these two statements carefully and select the answers to these items using the code given below: Statement (I): By organizing various ‘optical functions' into an ‘array structure’ via nano-pattern replication, ‘spatial integration’ is established.Statement (II): By adding a nano-optics layer or layers to functional optical materials, the ‘hybrid integration’ is possible to be achieved.
A.	Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
B.	Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)
C.	Statement (I) is true but Statement (II) is false
D.	Statement (I) is false but Statement (II) is true
Answer» C. Statement (I) is true but Statement (II) is false

Discussion

69.	Cementite contains Carbon to the tune of
A.	0.6%
B.	5%
C.	3.6%
D.	6.67%
Answer» E.

Discussion

70.	In the magnetic core the electromotive forces (emf) induced in accordance with Faraday’s law of electromagnetic induction give rise to
A.	Eddy current
B.	Excitation current
C.	Armature current
D.	Field current
Answer» B. Excitation current

Discussion

71.	Ferro-electric material have a
A.	high dielectric constant which varies non-linearly
B.	low dielectric constant and is non-linear
C.	high dielectric constant which varies linearly
D.	low dielectric constant but linear
Answer» B. low dielectric constant and is non-linear

Discussion

72.	Consider the following statements regarding the behavior of dislocations:1) Only edge dislocation and mixed dislocation can have glide motion.2) A screw dislocation cannot have glide motion.3) Dislocation moves in the direction perpendicular to that of shear stress.4) The motion of dislocation occurs on a slip plane that contains Burger’s vector and a direction vector.Which of the above statements are correct?
A.	1, 2 and 3 only
B.	1, 2 and 4 only
C.	2, 3 and 4 only
D.	1, 2, 3 and 4
Answer» C. 2, 3 and 4 only

Discussion

73.	If the interaction between the atomic permanent dipole moments is zero or negligible and the individual dipole moments are oriented at random, the material will be a
A.	Ferromagnetic material
B.	Ferrimagnetic material
C.	Paramagnetic material
D.	Antiferromagnetic material
Answer» D. Antiferromagnetic material

Discussion

74.	Hardenability of steel is assessed by
A.	Charpy impact test
B.	Rockwell hardness test
C.	Jominy end-quench test
D.	Open-hole test
Answer» D. Open-hole test

Discussion

75.	Enameled wires are preferred to cotton-covered wires to
A.	withstand higher temperature
B.	improve heat dissipation
C.	reduce the resistivity
D.	increase the mechanical strength
Answer» B. improve heat dissipation

Discussion

76.	If the task for you is to improve the strength of steel at elevated temperature, which one of the following alloying element would you prefer :
A.	Copper
B.	Tungsten
C.	Aluminium
D.	Zinc
Answer» C. Aluminium

Discussion

77.	Atomic radius of BCC structure is given by ______.
A.	\(\frac{{a\sqrt 3 }}{4}\)
B.	\(\frac{{4a}}{{\sqrt 3 }}\)
C.	\(\frac{a}{{2\sqrt 2 }}\)
D.	\(a{\rm{ }}/{\rm{ }}2\)
Answer» B. \(\frac{{4a}}{{\sqrt 3 }}\)

Discussion

78.	Molybdenum has a Body-Cantered Cubic (BCC) structure with an atomic radius of 1.36 Ȧ .Then the lattice parameter for BCC molybdenum is
A.	2.77 Ȧ
B.	3.14 Ȧ
C.	5.12 Ȧ
D.	6.28 Ȧ
Answer» C. 5.12 Ȧ

Discussion

79.	Lead is widely used in
A.	Transformers
B.	Switch gear
C.	Galvanized pipes
D.	Batteries
Answer» E.

Discussion

80.	In the figure shown below, Miller indices [0 2 1] have the direction of
A.	B
B.	A
C.	D
D.	C
Answer» D. C

Discussion

81.	Addition of Sulphur to stainless steel increases which of the following?
A.	Machinability
B.	Hardness
C.	Wear resistance
D.	Corrosion resistance
Answer» B. Hardness

Discussion

82.	A reaction-bonded silicon nitride ceramic has a strength of 300 MPa and a fracture toughness of 3.6 MPa √m. With y = 1 in the fracture toughness equation, what is the largest size of internal crack that this material can withstand without fracturing?
A.	91.6 μm
B.	82.3 μm
C.	74.6 μm
D.	45.8 μm
Answer» B. 82.3 μm

Discussion

83.	If the diameter of a copper wire is increased by two times keeping its terminal voltage same, then the drift velocity will
A.	become twice
B.	become half
C.	become four times
D.	remain unchanged
Answer» E.

Discussion

84.	In the Pb-Sn system, the fraction of total a phase is 3 times the fraction of b phase at eutectic temperature of 182°C, Pb with 19% Sn dissolved in it, Sn with 2.5% Pb dissolved in it, and liquid is in equilibrium. The alloy compositions of tin (Sn) and lead (Pb) are nearly
A.	28.6% and 71.4%
B.	38.6% and 61.4%
C.	48.6% and 51.4%
D.	58.6% and 41.4%
Answer» C. 48.6% and 51.4%

Discussion

85.	______ is the property of a material to resist fracture due to high impact blows like hammer blows.
A.	Fatigue
B.	Creep
C.	Toughness
D.	Malleability
Answer» D. Malleability

Discussion

86.	Direction: It consists of two statements, one labeled as ‘Statement (I)’ and the others as ‘Statement (II)’. You are to examine these two statements carefully and select the answer using the codes given below:Statement (I): Electrostriction occurs due to piezoelectricity which in the reverse effect i.e. the production of polarization on application of mechanical stress if the lattice has no centre of sysmetry.Statement (II): When an electric field is applied to a substance it becomes polarized, the electrons and nuclei assume new geometric positions and the mechanical dimensions of the substance are altered.
A.	Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
B.	Both Statement (I) and Statement (II) are individually true but Statement (II) is NOT the correct explanation of Statement (I)
C.	Statement (I) is true but Statement (II) is false
D.	Statement (I) is false but Statement (II) is true
Answer» B. Both Statement (I) and Statement (II) are individually true but Statement (II) is NOT the correct explanation of Statement (I)

Discussion

87.	If the vacancies move through the crystal lattice, the behaviour is called
A.	Nabarro-Herring creep
B.	Coble creep
C.	Power law creep
D.	Diffusion creep
Answer» E.

Discussion

88.	Direction: It consists of two statements, one labelled as ‘Statement (I)’ and the others as ‘Statement (II)’. You are to examine these two statements carefully and select the answer using the codes given below:Statement (I): Mechanically, pearlite has properties intermediate between the soft ductile ferrite and the hard brittle cementite.Statement (II): Alpha iron can be made magnetic above 768° C.
A.	Both Statement (I) and Statement (II) individually true and Statement (II) is the correct explanation of Statement (I)
B.	Both statement (I) and Statement (II) are individually true, but Statement (II) is not the correct explanation of Statement (I)
C.	Statement (I) is true, but Statement (II) is false
D.	Statement (I) is false, but Statement (II) is true
Answer» D. Statement (I) is false, but Statement (II) is true

Discussion

89.	Out of the following which is the amorphous material?
A.	Lead
B.	Brass
C.	Glass
D.	Silver
Answer» D. Silver

Discussion

90.	Permanent magnet loses the magnetic behaviour when heated because of1. atomic vibration2. dipole vibration3. realignment of dipolesWhich of the above are correct?
A.	1 and 2 only
B.	1 and 3 only
C.	1, 2 and 3
D.	2 and 3 only
Answer» D. 2 and 3 only

Discussion

91.	Materials in which the permanent dipoles interact with each other so heavily that they tend to align parallel to each other are called
A.	Ferromagnetic
B.	Ferrimagentic
C.	Paramagnetic
D.	Anti-ferromagnetic
Answer» B. Ferrimagentic

Discussion

92.	Consider the following statements regarding water:1. Water is an polar molecule2. Water molecules align themselves in an electric field3. Water molecules vary their alignment if the applied electric polarity changes with time 4. Water molecules align themselves in an magnetic fieldWhich of the above statements are correct?
A.	1, 2 and 3 only
B.	1, 2 and 4 only
C.	3 and 4 only
D.	1, 2, 3 and 4
Answer» B. 1, 2 and 4 only

Discussion

93.	Match List-I and List-II using code given below :List-IA. Car dash boardB. Aircraft windowsC. Conduit pipesD. Bearings and gearsList-II1. Polyvinylchloride (PVC)2. TEFLON3. Polyacrylonitrile4. PolymethylmethacrylateCodes :
A.	A-1, B-2, C-3, D-4
B.	A-3, B-4, C-1, D-2
C.	A-4, B-3, C-2, D-1
D.	A-2, B-3, C-4, D-1
Answer» C. A-4, B-3, C-2, D-1

Discussion

94.	In a simple cubic structure, atomic packing factor is nearly
A.	0.9
B.	0.7
C.	0.5
D.	0.3
Answer» D. 0.3

Discussion

95.	For applied load P kg, diameter of ball D mm and diameter of indentation d mm, the Brinell hardness number is given by
A.	\({B_{HN}} = \frac{P}{{\frac{\pi }{2}\left( {D - \sqrt {{D^2} - {d^2}} } \right)}}\)
B.	\({B_{HN}} = \frac{D}{{\frac{\pi }{2}\left( {D - \sqrt {{D^2} - {d^2}} } \right)}}\)
C.	\({B_{HN}} = \frac{PD}{{\frac{\pi }{2}\left( {D - \sqrt {{D^2} - {d^2}} } \right)}}\)
D.	\({B_{HN}} = \frac{P}{{(\frac{\pi D }{2})\left( {D - \sqrt {{D^2} - {d^2}} } \right)}}\)
Answer» E.

Discussion

96.	Graphene is
A.	A two dimensional material consisting of a single layer of carbon atoms arranged in a honeycomb or chicken wire structure.
B.	A tube-shaped material made of carbon, having a diameter measuring on the nanometer scale.
C.	Completely non-transparent material.
D.	None of the above
Answer» B. A tube-shaped material made of carbon, having a diameter measuring on the nanometer scale.

Discussion

97.	Figure-out the odd point in the following
A.	Proportional limit
B.	Elastic limit
C.	Yield point
D.	Fracture point
Answer» E.

Discussion

98.	As percentage of carbon increases in steel, its _________ decreases.
A.	Corrosion resistance
B.	Ductility
C.	Hardness
D.	Ultimate strength
Answer» C. Hardness

Discussion

99.	Consider the following statements and choose the correct one:(P) Hardness is the resistance of a material to indentation.(Q) Elastic modulus is a measure of ductility.(R) Deflection depends on stiffness.(S) The total area under the stress-strain curve is a measure of resilience.
A.	P and Q only
B.	Q and S only
C.	P and R only
D.	R and S only
Answer» D. R and S only

Discussion

100.	An electrical breakdown of a p-n junction occurs if
A.	forward voltage increases up to the rating
B.	reverse voltage increases beyond the rating
C.	forward voltage decreases below the rating
D.	reverse voltage decreases below the rating
Answer» C. forward voltage decreases below the rating

Discussion

Explore topic-wise MCQs in Mechanical Engineering.

Formation of Ferrite and Cementite from Austenite takes place at:

Alloy steel containing 36% nickel is called _____.

Dislocations in materials are

Match the heat treatment processes (Group A) and their associated effects on properties (Group B) of medium carbon steel :Group AGroup BP : TemperingI : Strengthening and grain refinementQ : QuenchingII : Inducing toughnessR : AnnealingIII : HardeningS : NormalizingIV : Softening

If a pair of one cation and one anion is missing in an ionic crystal such that those pairs of ions are equal to maintain electrical neutrality, then that pair of vacant sites is called

Mild steel belongs to which of the category?

Babbit is an alloy of

Denoting L as liquid and M as solid in a phase-diagram with the subscripts representing different phases, a eutectoid reaction is described by

_______ is commonly used for making household utensils.

_________ is present in high percentage in magnet steel.

In Glass Fiber Reinforced plastic (GFRP) composites with long fibers, the role of matrix is to(P) Support and transfer the stresses to the fibers(Q) Reduced propagation of cracks (R) Carry the entire load(S) Protect the fibers against damageThe correct statements are

Consider the following statements:Machine tool beds are made using grey cast iron due to1. high tensile strength and ductility2. high compressive strength and damping property3. castability and low cost of production4. machinability and low material costWhich of the above statements are correct?

Match the items in columns I and II.Column IColumn II(P) Charpy test(1) Fluidity(Q) Knoop test(2) Microhardness(R) Spiral test(3) Formability(S) Cupping test(4) Toughness (5) Permeability

Behaviour of conductors, semiconductors and insulators is explained on the basis of

A mixture of chemical compounds or elements that have a single chemical composition and solidifies at the lowest temperature than any other composition made up of the same ingredients.

Cementite has the chemical formula:

Cementite contains Carbon to the tune of

In the magnetic core the electromotive forces (emf) induced in accordance with Faraday’s law of electromagnetic induction give rise to

Ferro-electric material have a

If the interaction between the atomic permanent dipole moments is zero or negligible and the individual dipole moments are oriented at random, the material will be a

Hardenability of steel is assessed by

Enameled wires are preferred to cotton-covered wires to

If the task for you is to improve the strength of steel at elevated temperature, which one of the following alloying element would you prefer :

Atomic radius of BCC structure is given by ______.

Molybdenum has a Body-Cantered Cubic (BCC) structure with an atomic radius of 1.36 Ȧ .Then the lattice parameter for BCC molybdenum is

Lead is widely used in

In the figure shown below, Miller indices [0 2 1] have the direction of

Addition of Sulphur to stainless steel increases which of the following?

A reaction-bonded silicon nitride ceramic has a strength of 300 MPa and a fracture toughness of 3.6 MPa √m. With y = 1 in the fracture toughness equation, what is the largest size of internal crack that this material can withstand without fracturing?

If the diameter of a copper wire is increased by two times keeping its terminal voltage same, then the drift velocity will

In the Pb-Sn system, the fraction of total a phase is 3 times the fraction of b phase at eutectic temperature of 182°C, Pb with 19% Sn dissolved in it, Sn with 2.5% Pb dissolved in it, and liquid is in equilibrium. The alloy compositions of tin (Sn) and lead (Pb) are nearly

______ is the property of a material to resist fracture due to high impact blows like hammer blows.

If the vacancies move through the crystal lattice, the behaviour is called

Out of the following which is the amorphous material?

Permanent magnet loses the magnetic behaviour when heated because of1. atomic vibration2. dipole vibration3. realignment of dipolesWhich of the above are correct?

Materials in which the permanent dipoles interact with each other so heavily that they tend to align parallel to each other are called

Match List-I and List-II using code given below :List-IA. Car dash boardB. Aircraft windowsC. Conduit pipesD. Bearings and gearsList-II1. Polyvinylchloride (PVC)2. TEFLON3. Polyacrylonitrile4. PolymethylmethacrylateCodes :

In a simple cubic structure, atomic packing factor is nearly

For applied load P kg, diameter of ball D mm and diameter of indentation d mm, the Brinell hardness number is given by

Graphene is

Figure-out the odd point in the following

As percentage of carbon increases in steel, its _________ decreases.

Consider the following statements and choose the correct one:(P) Hardness is the resistance of a material to indentation.(Q) Elastic modulus is a measure of ductility.(R) Deflection depends on stiffness.(S) The total area under the stress-strain curve is a measure of resilience.

An electrical breakdown of a p-n junction occurs if