Multiple Choice.
1. What characteristic clearly distinguishes semiconductors from metals and nonmetals?
A. luster B. electrical conductivity C. ductility D. none of the above
2. In which column on the periodic table do the elemental semiconductors reside?
A. I B. III C. IV D. V
3. Which of the following are semiconductor materials?
A. gallium arsenide B. germanium C. silicon D. all of the ab ove
4. Why are semiconductors valuable in modern electronics?
A. use low power C. fast switching
B. reliable D. all of the above
5. Which electronic devices are primarily made from semiconductors?
A. transistors B. resistors C. capacitors D. none of the above
6. How does the conductivity in pure semiconductors vary with temperature?
A. conductivity increases as temperature goes down
B. conductivity increases as temperature goes up
C. conductivity does not change with temperature
7. What explains why semiconductors have different electrical properties from metals?
A. more valence electrons C. band gap structure
B. fewer valence electrons D. no differences
8. Semiconductors exhibit which of the following opto-electronic properties?
A. photoresistivity C. production of photoel ectric currents
B. photoconductivity D. all of the above
SHORT ANSWER.
1. Name the 3 categories of materials based on their ability to conduct electricity.
2. Label each as C-conductor, SC semiconductor, or I- insulator:
Copper wire____ Glass rod ____ Silicon chip _____
3. Which would have a smaller energy gap between the valence band and the conduction band, glass or silicon? ____________
4. In a metallic conductor, are the valence shells filled, empty, or partially filled? _________
5. In a semiconductor, are the valence shells filled, empty, or partially filled? __________
6. Are electrons in the valence band of a semiconductor in the bonding or anti bonding state? ______________
7. At what temperature are there no electrons in the conduction band of a semiconductor?
8. As one electron is promoted from the valence band to the conduction band, a _____ is formed in the valence band.
9. As the temperature increases, (more, less) electrons can be promoted to the conduction band?
10. Both ________ and ______ are considered charge carriers.
11. Group ___ elements are used as dopants to produce n-type semiconductors, because they have ____ _______ __________ than the original Group 4 material.
12. Group __ elements are used as dopants to produce p-type semiconductors, because they have ____ _______ _________ than the original Group 4 material.
13. A diode contains both ____________ and ___________ regions.
14. For current to flow through a diode, the positive terminal of the power supply must be connected to the ___-type material.
Multiple Choice.
1. What characteristic clearly distinguishes semiconductors from metals and nonmetals?
A. luster B. electrical conductivity C. ductility D. none of the above
2. In which column on the periodic table do the elemental semiconductors reside?
A. I B. III C. IV D. V
3. Which of the following are semiconductor materials?
A. gallium arsenide B. germanium C. silicon D. all of the above
4. Why are semiconductors valuable in modern electronics?
A. use low power C. fast switching
B. reliable D. all of the above
5. Which electronic devices are primarily made from semiconductors?
A. transistors B. resistors C. capacitors D. none of the above
6. How does the conductivity in pure semiconductors vary with temperature?
A. conductivity increases as temperature goes down
B. conductivity increases as temperature goes up
C. conductivity does not change
7. What explains why semiconductors have different electrical properties from metals?
A. more valence electrons C. band gap structure
B. fewer valence electrons D. no differences
8. Semiconductors exhibit which of the following opto-electronic properties?
A. photoresistivity C. production of photoelectric currents
B. photoconductivity D. all of the above
SHORT ANSWER.
1. Name the 3 categories of materials based on their ability to conduct electricity.
conductors, semiconductors, insulators
2. Label each as C-conductor, SC semiconductor, or I- insulator:
Copper wire__C__ Glass rod _I___ Silicon chip __SC___
3. Which would have a smaller energy gap between the valence band and the conduction band, glass or silicon? _Silicon__
4. In a metallic conductor, are the valence shells filled, empty, or partially filled?
less than half filled
5. In a semiconductor, are the valence shells filled, empty, or partially filled? __filled_
6. Are electrons in the valence band of a semiconductor are in the bonding or anti bonding state? _bonding____
7. At what temperature are there no electrons in the conduction band of a semiconductor? 0[[ring]]K
8. As one electron is promoted from the valence band to the conduction band, a _hole_ is formed in the valence band.
9. As the temperature increases, (more, less) electrons can be promoted to the conduction band?
10. Both _electrons _ and _holes_ are considered charge carriers.
11. Group 5_ elements are used as dopants to produce n-type semiconductors, because they have _one more electron_ than the original Group 4 material.
12. Group _3_ elements are used as dopants to produce p-type semiconductors, because they have one less electron_ than the original Group 4 material.
13. A diode contains both _n-type_ and __p-type_ regions.
14. For current to flow through a diode, the positive terminal of the power supply must be connected to the _p-type material.