$A$ semiconductor doped with a donor impurity is

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 $m^{-3}$)?

If $n_{e}$ and $n_{h}$ are the number of electrons and number of holes respectively in a semiconductor heavily doped with phosphorus,then:

Which of the following statements is true for an $N$-type semiconductor?

$A$ donor impurity results in

$A$ semiconductor has electron and hole mobilities $\mu_{n}$ and $\mu_{p}$ respectively. If its intrinsic carrier density is $n_{i}$,what will be the value of hole concentration $p$ for which the conductivity will be minimum at a given temperature?