If $n_{e}$ and $n_{h}$ are concentrations of electrons and holes in a semiconductor,then the intrinsic carrier concentration $(n_i)$ in thermal equilibrium is

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

Silicon is a semiconductor. If a small amount of $As$ is added to it,then its electrical conductivity . . . . . . .

In a sample of pure silicon, $10^{13} \text{ atoms/cm}^3$ of phosphorus is added. If all donor atoms are active and the electron mobility is $1200 \text{ cm}^2/\text{V}\cdot\text{s}$, what will be the resistivity at $20^\circ\text{C}$ in $\Omega\cdot\text{cm}$?

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

The Bohr radius of the fifth electron of phosphorus (atomic number $Z = 15$) acting as a dopant in silicon (relative dielectric constant $\varepsilon_r = 12$) is ....... $\mathring{A}$.