The state of the energy gained by valence electrons when the temperature is raised or when an electric field is applied is called as:

Carbon,Silicon,and Germanium atoms each have four valence electrons. If their bandgaps are represented by $(E_g)_C$,$(E_g)_{Si}$,and $(E_g)_{Ge}$ respectively,which of the following relations is correct?

Would there be any advantage to adding $n$-type or $p$-type impurities to copper?

The energy band diagrams for three semiconductor samples of silicon are as shown. We can then assert that

$GaAs$ (Gallium Arsenide) is a ....... .

$A$ piece of copper and another of germanium are cooled from room temperature to $80\, K$. Which of the following is a correct statement?