Which statement is correct regarding the charge of doped semiconductors?

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

In an intrinsic semiconductor,the energy gap $E_{g}$ is $1.2 \; eV$. Its hole mobility is much smaller than electron mobility and independent of temperature. What is the ratio between conductivity at $600 \; K$ and that at $300 \; K$? Assume that the temperature dependence of intrinsic carrier concentration $n_{i}$ is given by $n_{i} = n_{0} \exp \left(-\frac{E_{g}}{2 k_{B} T}\right)$,where $n_{0}$ is a constant.

Which one of the following statements is true? $A$ p-type semiconductor is doped with

In a semiconductor,the concentrations of electrons and holes are $8 \times 10^{18} \, m^{-3}$ and $5 \times 10^{18} \, m^{-3}$ respectively. If the mobilities of electrons and holes are $2.3 \, m^2/V \cdot s$ and $0.01 \, m^2/V \cdot s$ respectively,then the semiconductor is:

The process of adding impurities to a pure semiconductor is called