MTE 271 TEST 4 QUESTIONS WITH
100% CORRECT ANSWERS
Which from the following would affect electrical conductivity of metals and alloys? -
Answer- Temperature and Composition
With an increase in temperature, the electrical conductivity of metals and alloys
decreases. This is due to a decrease in _________________ with an increase in
temperature. - Answer- mobility
With an increase in solute content, the electrical conductivity of alloys decreases. This is
due to a decrease in _________________ with an increase in solute content. - Answer-
mobility
The electrical conductivity of semiconductors ________________ with an increase in
temperature. - Answer- increases
The electrical conductivity of semiconductors ________________ with an increase in
temperature. - Answer- increases
General properties of ceramics include - Answer- low thermal and electrical conductivity
With an increase in temperature, the electrical conductivity of semiconductors
increases. This is due to an increase in _______________ with an increase in
temperature. - Answer- number of charge carriers
What is responsible for heat conduction in ceramics? - Answer- Lattice vibrations of ions
Which from the following has, in general, highest band gap energy? - Answer-
Insulators
Which family of materials exhibits lowest values of thermal conductivity? - Answer-
X-rays have more energy than microwaves - Answer- True
Because metals have no energy gap, they require high-energy photons to excite their
electrons to higher energy levels. - Answer- False
100% CORRECT ANSWERS
Which from the following would affect electrical conductivity of metals and alloys? -
Answer- Temperature and Composition
With an increase in temperature, the electrical conductivity of metals and alloys
decreases. This is due to a decrease in _________________ with an increase in
temperature. - Answer- mobility
With an increase in solute content, the electrical conductivity of alloys decreases. This is
due to a decrease in _________________ with an increase in solute content. - Answer-
mobility
The electrical conductivity of semiconductors ________________ with an increase in
temperature. - Answer- increases
The electrical conductivity of semiconductors ________________ with an increase in
temperature. - Answer- increases
General properties of ceramics include - Answer- low thermal and electrical conductivity
With an increase in temperature, the electrical conductivity of semiconductors
increases. This is due to an increase in _______________ with an increase in
temperature. - Answer- number of charge carriers
What is responsible for heat conduction in ceramics? - Answer- Lattice vibrations of ions
Which from the following has, in general, highest band gap energy? - Answer-
Insulators
Which family of materials exhibits lowest values of thermal conductivity? - Answer-
X-rays have more energy than microwaves - Answer- True
Because metals have no energy gap, they require high-energy photons to excite their
electrons to higher energy levels. - Answer- False
