An intrinsic semiconductor is electrically neutral. What is the electrical state of an extrinsic semiconductor?

Which of the following energy band diagrams shows the $N-$type semiconductor and $P-$type semiconductor respectively?

Pure Silicon crystal at $300 \ K$ has equal electron and hole concentration of $1.5 \times 10^{16} \ m^{-3}$. Doping by indium increases $n_h = 4.5 \times 10^{22} \ m^{-3}$. The $n_e$ in the doped silicon is:

$A$ semiconductor has equal electron and hole concentration of $6 \times 10^8 \, m^{-3}$. On doping with a certain impurity,the electron concentration increases to $9 \times 10^{12} \, m^{-3}$. The new hole concentration is:

Germanium $(Ge)$ is doped with Aluminum $(Al)$. If the concentration of acceptor atoms is $N_A \cong 10^{21} \text{ atoms/m}^3$ and the intrinsic carrier concentration is $n_i = 10^{19} \text{ m}^{-3}$,then the concentration of electrons is:

The temperature $(T)$ dependence of resistivity $(\rho)$ of a semiconductor is represented by