The valence of the impurity atom that is to be added to a germanium crystal to make it an $N$-type semiconductor is:

$A$ transistor is a/an

When a small amount of impurity atoms are added to a semiconductor,then generally its resistivity

$A$ semiconductor has equal electron and hole concentration of $2 \times 10^8 \ m^{-3}$. On doping with a certain impurity, the electron concentration increases to $4 \times 10^{10} \ m^{-3}$. What is the new hole concentration of the semiconductor?

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 $nm$)

Assertion: The number of electrons in a $p-$type silicon semiconductor is less than the number of electrons in a pure silicon semiconductor at room temperature.
Reason: It is due to the law of mass action.