In a $P-$type semiconductor,

$A$ $P$-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 $h = 6.6 \times 10^{-34} \; J \cdot s$, speed of light $c = 3 \times 10^8 \; m/s$)

$A$ $P$-type semiconductor is .......

An intrinsic semiconductor is electrically neutral. What is the electrical state of an extrinsic semiconductor?

To a germanium sample,traces of gallium are added as an impurity. The resultant sample would behave like

$A$ positive hole in a semiconductor is