In extrinsic $P$ and $N$-type semiconductor materials,the ratio of the impurity atoms to the pure semiconductor atoms is about

$A$ silicon specimen is made into a $P$-type semiconductor by doping,on an average,one Indium atom per $5 \times 10^7$ silicon atoms. If the number density of atoms in the silicon specimen is $5 \times 10^{28} \text{ atoms}/m^3$,then the number of acceptor atoms in silicon per cubic centimetre will be:

When germanium is doped with phosphorus,the doped material has

When an $N-$type semiconductor is heated,what happens to the charge carriers?

Which of the following statements is $\underline{TRUE}$ for $n$-type semiconductor?

If a small amount of antimony is added to germanium crystal,