Donor type impurity is found in

The acceptor level of a $p$-type semiconductor is $6 \ eV$ above the valence band. The maximum wavelength of light which can create a hole would be: (Given $hc = 1242 \ eV \ nm$) (in $nm$)

If the ratio of the number density of electrons to the number density of holes in a semiconductor is $7/5$ and the ratio of their currents is $7/4$,what is the ratio of their drift velocities?

$A$ semiconductor has electron and hole mobilities $\mu_{n}$ and $\mu_{p}$ respectively. If its intrinsic carrier density is $n_{i}$,what will be the value of hole concentration $p$ for which the conductivity will be minimum at a given temperature?

When the conductivity of a semiconductor is only due to breaking of covalent bonds, the semiconductor is called

$A$ potential difference of $2.5 \,V$ is applied across the faces of a germanium crystal plate. The face area of the crystal is $1 \,cm^2$ and its thickness is $1.0 \,mm$. The free electron concentration in germanium is $2 \times 10^{19} \,m^{-3}$ and the electron and hole mobilities are $0.33 \,m^2/V \cdot s$ and $0.17 \,m^2/V \cdot s$ respectively. The current across the plate will be .......... $A$.