The valence of an impurity added to germanium crystal in order to convert it into a $P-$type semiconductor is

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

If $n_e$ and $v_d$ are the number density of electrons and drift velocity in a semiconductor,respectively,what happens when the temperature is increased?

$A$ 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?

The process of adding impurities to a pure semiconductor is called

$A$ $P$-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 $h = 6.6 \times 10^{-34} \, J-s$, speed of light $c = 3 \times 10^8 \, m/s$, charge of electron $e = 1.6 \times 10^{-19} \, C$)