Minority carriers in a $p$-type semiconductor are

In a pure silicon $(n_i = 10^{16}/m^3)$ crystal at $300\, K$,$10^{21}$ atoms of phosphorus are added per cubic meter. The new hole concentration will be

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

The most commonly used material for making transistors is

An $n$-type and a $p$-type silicon semiconductor can be obtained by doping pure silicon with

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 $m^{-3}$)?