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

In a semiconductor,the ratio of the number of electrons to the number of holes is $7/5$ and the ratio of their currents is $7/4$. What is the ratio of their drift velocities?

What are impure semiconductors,doping,and dopants?

The following band-energy diagram represents:

$A$ 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:

Write four points in distinguishing between $p$-type semiconductor and $n$-type semiconductor.