TEST 1- MEGR 3161 QUESTIONS AND
ANSWERS
Materials Science and Engineering is about:
a). How to make a specific component.
b). The relationship between microstructure and the properties of materials, and based
on
this relationship how to process and material for desired properties and performance.
c). How to process a material for desired properties. - Correct Answers -B. The
relationship between microstructure and the properties of materials, and based on
this relationship how to process and material for desired properties and performance
The key components of Materials Science and Engineering include? - Correct Answers
-Processing>Structure>Properties>Performance
The primary types of materials of technological importance are the following: a). Metals,
semiconductors and polymers.
b). Metals, ceramics, and polymers.
c). Biomaterials, semiconductors and composites. - Correct Answers -b. Metals,
ceramics and polymers
The electrons that occupy the outermost filled shell are called: - Correct Answers -
Valence Electrons
As a give temperature, carbon atoms diffuse faster than Fe atoms in an Fe lattice
because of the following: - Correct Answers -Carbon atoms diffuse by interstitial
mechanism, which has much smaller activation energy than the diffusion of Fe lattice by
vacancy diffusion
Rank the magnitudes of the diffusion coefficients from greatest to least for the following
systems: (i)N in FE at 700C (ii) Cr in FE at 700C (iii) N in Fe at 900C (iv) Cr in FE at
900C - Correct Answers -(iii)> (i)>(iv)>(ii)
For a given diffusion species and diffusion medium, at the same temperature, which of
the following diffusion paths in the fastest? - Correct Answers -surface
What type(s) of electron subshell(s) does a K shell contain? - Correct Answers -S
What is the maximum number of electrons that an L shell may contain? - Correct
Answers -8
, The net potential energy between a pair of bonded atoms: - Correct Answers -Reaches
its minimum value when the two atoms are at equilibrium
The three primary bonds in materials are:
a). Ionic, covalent and metallic.
b). Ionic, covalent and Van der Waals.
c). Van der Waals, covalent and metallic. - Correct Answers -A. Ionic, covalent and
metallic
Covalent bonds are:
A.Directional
B.Non-directional - Correct Answers -A. Directional
For metals, the larger the bonding energy:
a.) The lower the melting point
b.) The higher the melting point - Correct Answers -B. The higher the melting point
Ionic bonding in solids is caused by: - Correct Answers -Interaction between oppositely
charged nearest neighbor ions
Which of the following materials may form crystalline solids?:
a.) Polymers
b.) Metals
c.) Ceramics
d.) All of the above - Correct Answers -D.All of the above.
The crystal system classification that groups all crystals into 7 systems is based on -
Correct Answers -The lattice parameters(a,b,c & alpha, beta and gamma values) of the
unit cell
The properties of a single crystal are usually.
a.) anisotropic
b.) isotropic - Correct Answers -a.) anisotropic
If we do electron diffraction on a crystalline material, we have
a.) sharp and well-defined spot pattern
b.) haloes - Correct Answers -a.)sharp and well-defined spot pattern
The most common lattice structures for metals are - Correct Answers -FCC,BCC,HCP
The most dense packed directions in BCC and FCC lattice structures are: - Correct
Answers -BCC<111>;FCC<110>
The most dense packed planes in BCC and FCC lattice structures are - Correct
Answers -BCC{110};FCC{111}
ANSWERS
Materials Science and Engineering is about:
a). How to make a specific component.
b). The relationship between microstructure and the properties of materials, and based
on
this relationship how to process and material for desired properties and performance.
c). How to process a material for desired properties. - Correct Answers -B. The
relationship between microstructure and the properties of materials, and based on
this relationship how to process and material for desired properties and performance
The key components of Materials Science and Engineering include? - Correct Answers
-Processing>Structure>Properties>Performance
The primary types of materials of technological importance are the following: a). Metals,
semiconductors and polymers.
b). Metals, ceramics, and polymers.
c). Biomaterials, semiconductors and composites. - Correct Answers -b. Metals,
ceramics and polymers
The electrons that occupy the outermost filled shell are called: - Correct Answers -
Valence Electrons
As a give temperature, carbon atoms diffuse faster than Fe atoms in an Fe lattice
because of the following: - Correct Answers -Carbon atoms diffuse by interstitial
mechanism, which has much smaller activation energy than the diffusion of Fe lattice by
vacancy diffusion
Rank the magnitudes of the diffusion coefficients from greatest to least for the following
systems: (i)N in FE at 700C (ii) Cr in FE at 700C (iii) N in Fe at 900C (iv) Cr in FE at
900C - Correct Answers -(iii)> (i)>(iv)>(ii)
For a given diffusion species and diffusion medium, at the same temperature, which of
the following diffusion paths in the fastest? - Correct Answers -surface
What type(s) of electron subshell(s) does a K shell contain? - Correct Answers -S
What is the maximum number of electrons that an L shell may contain? - Correct
Answers -8
, The net potential energy between a pair of bonded atoms: - Correct Answers -Reaches
its minimum value when the two atoms are at equilibrium
The three primary bonds in materials are:
a). Ionic, covalent and metallic.
b). Ionic, covalent and Van der Waals.
c). Van der Waals, covalent and metallic. - Correct Answers -A. Ionic, covalent and
metallic
Covalent bonds are:
A.Directional
B.Non-directional - Correct Answers -A. Directional
For metals, the larger the bonding energy:
a.) The lower the melting point
b.) The higher the melting point - Correct Answers -B. The higher the melting point
Ionic bonding in solids is caused by: - Correct Answers -Interaction between oppositely
charged nearest neighbor ions
Which of the following materials may form crystalline solids?:
a.) Polymers
b.) Metals
c.) Ceramics
d.) All of the above - Correct Answers -D.All of the above.
The crystal system classification that groups all crystals into 7 systems is based on -
Correct Answers -The lattice parameters(a,b,c & alpha, beta and gamma values) of the
unit cell
The properties of a single crystal are usually.
a.) anisotropic
b.) isotropic - Correct Answers -a.) anisotropic
If we do electron diffraction on a crystalline material, we have
a.) sharp and well-defined spot pattern
b.) haloes - Correct Answers -a.)sharp and well-defined spot pattern
The most common lattice structures for metals are - Correct Answers -FCC,BCC,HCP
The most dense packed directions in BCC and FCC lattice structures are: - Correct
Answers -BCC<111>;FCC<110>
The most dense packed planes in BCC and FCC lattice structures are - Correct
Answers -BCC{110};FCC{111}
