Band Theory of Solids
Physics ⇒ Modern Physics
Band Theory of Solids starts at 11 and continues till grade 12.
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See sample questions for grade 12
A solid has a band gap of 2.5 eV. Is it more likely to be a conductor, semiconductor, or insulator?
A student claims that at high temperatures, even insulators can conduct electricity. Is this statement correct? Explain your answer.
Describe how doping affects the band structure of a semiconductor.
Describe the effect of temperature on the band gap of a semiconductor.
Describe what happens to the band structure of a semiconductor when it is heavily doped with donor atoms.
Explain the difference between direct and indirect band gap semiconductors.
Explain why pure silicon behaves as a semiconductor according to band theory.
A student claims that at high temperatures, even insulators can conduct electricity. Is this statement correct? Explain your answer.
Which of the following best describes the band theory of solids? (1) It explains the arrangement of atoms in a crystal lattice. (2) It describes the energy levels of electrons in isolated atoms. (3) It explains the formation of energy bands due to the overlap of atomic orbitals in solids. (4) It describes the movement of ions in a solid.
Which of the following best describes the conduction band? (1) It is the highest energy band that is completely filled with electrons. (2) It is the lowest energy band that is completely empty. (3) It is the band where electrons are free to move and contribute to electrical conduction. (4) It is the band containing the nucleus.
Which of the following best explains why insulators do not conduct electricity? (1) Their conduction band is partially filled. (2) Their valence band overlaps with the conduction band. (3) Their forbidden gap is very large. (4) They have free electrons in the conduction band.
Which of the following is a direct band gap semiconductor? (1) Silicon (2) Germanium (3) Gallium arsenide (4) Diamond
Fill in the blank: In a p-type semiconductor, the majority charge carriers are ________.
Fill in the blank: The electrical conductivity of a solid depends on the ________ between the valence band and the conduction band.
Fill in the blank: The process of adding impurities to a semiconductor to change its electrical properties is called ________.
The energy gap between the valence band and the conduction band in insulators is typically ________ than that in semiconductors.
State whether the following statement is true or false: The electrical conductivity of a semiconductor increases with temperature.
True or False: At absolute zero, a pure semiconductor behaves like an insulator.
True or False: In a metal, the conduction band is always completely filled at absolute zero.
True or False: In conductors, the valence band and conduction band overlap.
