Through a semiconductor,an electric current is due to the drift of

Which of the following statements is incorrect?

In a semiconductor,the concentration of electrons is $8 \times 10^{14} \text{ cm}^{-3}$ and that of the holes is $5 \times 10^{12} \text{ cm}^{-3}$. The semiconductor is

Let ${n_h}$ and ${n_e}$ be the number of holes and conduction electrons respectively in a semiconductor. Then

$P$-type semiconductor has acceptor levels $57 \, meV$ above the valence band. The maximum wavelength of light required to create a hole is (Planck's constant $h = 6.6 \times 10^{-34} \, J-s$)

$A$ potential difference of $2\,V$ is applied between the opposite faces of a $Ge$ crystal plate of area $1\,cm^{2}$ and thickness $0.5\,mm$. If the concentration of electrons in $Ge$ is $2 \times 10^{19}/m^{3}$ and mobilities of electrons and holes are $0.36\,m^{2}/(V\cdot s)$ and $0.14\,m^{2}/(V\cdot s)$ respectively,then the current flowing through the plate will be... (in $,A$)