A) Substances with energy gap of the order of 10 eV are insulators
B) The conductivity of a semiconductor increases with increases in temperature
C) In conductors the valence and conduction bands may overlap
D) The resistivity of a semiconductor increases with increase in temperature
Correct Answer: C
Solution :
[a] In insulators energy gap is of the order of S to 10 eV and it is practically impossible to impart this much amount of energy to the electrons in valence band. So as to jump to conduction band. So, choice [a] is correct. |
[b] In semiconductors with the rise in temperature more electrons from valence band jump to conduction band and this results in increase in conductivity. So, choice [b] is correct. |
[c] In conductors, the conduction band is either partially filled or the conduction band overlaps on die valence band. So, choice [c] is correct. |
[d] In semiconductor, resistivity, decreases with increase in temperature. So, choice [d] is wrong. |
You need to login to perform this action.
You will be redirected in
3 sec