MTE 271 TEST 3 QUESTIONS AND
ANSWERS
When dislocations in a material cannot move easily the hardness - Answer- increases
Yield point - Answer- The stress at which a material begins to plastically deform
Which is tougher Metals or ceramics? - Answer- Metals
Difference between true stress and engineering stress - Answer- instantaneous area vs.
original area
Heat capacity is a measure under - Answer- constant pressure and volume
If impurities are added to a metal, the thermal conduction - Answer- decreases
If a metal is heated up in a furnace then removed to cool, the surface will experience -
Answer- Compression stress
Metals are _________ susceptible to thermal shock failure than ceramics - Answer-
more
Conduction by holes is typically less efficient than conduction by electrons in an intrinsic
semiconductor - Answer- true
The typical electrical conductivity value/range for materials are: - Answer-
Semiconductor 10^-6 to 10^4
(Ω-m)^-1
Metal 10^7
(Ω-m)^-1
Insulator 10^-20 to 10^-10 (Ω-m)^-1
For nonmetallic materials, what is the name of the region that lies between the valence
and
conduction bands? - Answer- Energy band gap
For an n-type semiconductor, where is the Fermi level located? - Answer- In the middle
of the band gap
For a p-type semiconductor - Answer- hole concentration> than electron concentration.
ANSWERS
When dislocations in a material cannot move easily the hardness - Answer- increases
Yield point - Answer- The stress at which a material begins to plastically deform
Which is tougher Metals or ceramics? - Answer- Metals
Difference between true stress and engineering stress - Answer- instantaneous area vs.
original area
Heat capacity is a measure under - Answer- constant pressure and volume
If impurities are added to a metal, the thermal conduction - Answer- decreases
If a metal is heated up in a furnace then removed to cool, the surface will experience -
Answer- Compression stress
Metals are _________ susceptible to thermal shock failure than ceramics - Answer-
more
Conduction by holes is typically less efficient than conduction by electrons in an intrinsic
semiconductor - Answer- true
The typical electrical conductivity value/range for materials are: - Answer-
Semiconductor 10^-6 to 10^4
(Ω-m)^-1
Metal 10^7
(Ω-m)^-1
Insulator 10^-20 to 10^-10 (Ω-m)^-1
For nonmetallic materials, what is the name of the region that lies between the valence
and
conduction bands? - Answer- Energy band gap
For an n-type semiconductor, where is the Fermi level located? - Answer- In the middle
of the band gap
For a p-type semiconductor - Answer- hole concentration> than electron concentration.
