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

Which of the following energy band diagrams shows the $N-$ type semiconductor?

$A$ 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?

In a $P-$type semiconductor,germanium is doped with

An $n$-type and a $p$-type silicon semiconductor can be obtained by doping pure silicon with

Let $n_e$ be the number density of electrons and $v_d$ be the drift velocity in a semiconductor. When the temperature is increased: