$P-$type semiconductor is formed when:

The number of silicon atoms per $m^{3}$ is $5 \times 10^{28}$. This is doped simultaneously with $5 \times 10^{22}$ atoms per $m^{3}$ of Arsenic and $5 \times 10^{20}$ atoms per $m^{3}$ of Indium. Calculate the number of electrons and holes. Given that $n_{i} = 1.5 \times 10^{16} \; m^{-3}$. Is the material $n$-type or $p$-type?

Which of the following statements is incorrect?

What will be the conductivity of a pure silicon crystal at $300 \ K$? Given that the intrinsic carrier concentration is $1.072 \times 10^{10} \ cm^{-3}$ and at this temperature,the electron mobility $\mu_n = 1350 \ cm^2 / (V \cdot s)$ and hole mobility $\mu_p = 480 \ cm^2 / (V \cdot s)$.

In a $p-$type semiconductor,which of the following statements is true?

Suppose a pure $Si$ crystal has $5 \times 10^{28}$ atoms $m^{-3}$. It is doped with $1 \text{ ppm}$ concentration of pentavalent $As$. Calculate the number of electrons and holes. $(n_i = 1.5 \times 10^{16} \text{ m}^{-3})$