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

What is the relation between the number density of holes $(n_h)$ and free electrons $(n_e)$ in an intrinsic semiconductor at room temperature?

$A$ 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:

What are $n$-type and $p$-type semiconductors? Name the majority and minority charge carriers in each.

$A$ positive hole in a semiconductor is

In an extrinsic semiconductor,the number densities of holes and electrons are ${N_p}$ and ${N_e}$ respectively. Then: