In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is a/an:
1. | \(\mathrm{p}\text-\)type semiconductor |
2. | insulator |
3. | metal |
4. | \(\mathrm{n}\text-\)type semiconductor |
1. | The resistivity of a semiconductor increases with an increase in temperature. |
2. | Substances with an energy gap of the order of \(10~\text{eV}\) are insulators. |
3. | In conductors, the valence and conduction bands may overlap. |
4. | The conductivity of a semiconductor increases with an increase in temperature. |
Carbon, Silicon, and Germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy gaps represented by \(\left(E_g\right)_C,(E_g)_{Si}~\text{and}~(E_g)_{Ge}\) respectively. Which one of the following relationships is true in their case?
1. \(\left(E_g\right)_C<\left(E_g\right)_{G e} \)
2. \(\left(E_g\right)_C>\left(E_g\right)_{S i} \)
3. \(\left(E_g\right)_C=\left(E_g\right)_{S i} \)
4. \(\left(E_g\right)_C<\left(E_g\right)_{S i}\)
1. | in the case of \(\mathrm{C},\) the valence band is not completely filled at absolute zero temperature. |
2. | in the case of \(\mathrm{C},\) the conduction band is partly filled even at absolute zero temperature. |
3. | the four bonding electrons in the case of \(\mathrm{C}\) lie in the second orbit, whereas in the case of \(\mathrm{Si},\) they lie in the third. |
4. | the four bonding electrons in the case of \(\mathrm{C}\) lie in the third orbit, whereas for \(\mathrm{Si},\) they lie in the fourth orbit. |