Select the correct statement s from the following I In conductors the valence and conduction bands m......

Select the correct statement(s) from the following.
I. In conductors, the valence and conduction bands may overlap.
II. Substances with energy gap of the order of 10 eV are insulators.
III. The resistivity of a semiconductor increases with increase in temperature.
IV. The conductivity of a semiconductor increases with increase in temperature.

I, II and IV

In insulators energy gap is the order of 5 to 10eV and it is partically impossible to impart this much amount of energy to the electrons in valence band. ... In conductors, the conduction band is either partially fielld or the conduction band overlap on the valence band.

By: Ramesh Kumar