For pure $Ge$,the intrinsic carrier density is $10^{19} \ m^{-3}$. If donor impurity is added with a density of $10^{23} \ m^{-3}$,what will be the hole density (in $m^{-3}$)?

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

Write four points in distinguishing between $p$-type semiconductor and $n$-type semiconductor.

Mobilities of electrons and holes in a sample of intrinsic $Ge$ at room temperature are $0.35 \, m^2/V-s$ and $0.18 \, m^2/V-s$ respectively. If the electron and hole densities are each equal to $2.5 \times 10^{19} \, /m^3$,the $Ge$ conductivity will be.....$S/m$ (in $.12$)

Which of the following is an inorganic compound semiconductor?

Silicon is a semiconductor. If a small amount of $As$ is added to it,then its electrical conductivity . . . . . . .