If $n_{\mathrm{e}}$ and $n_{\mathrm{h}}$ are the number of electrons and holes in a semiconductor heavily doped with phosphorus, then,

Current in the circuit will be

Which of the following statements concerning the depletion zone of an unbiased $p$ - $n$ junction is (are) true-
A. The width of the zone is independent of the dopants (impurities)
B. The width of the zone is dependent on the densities of the dopants.
C. The electric field in the zone is produced by the ionised dopant atoms.
D. The electric field in the zone is provided by the electrons in the conduction band and the holes in the valence band.

Correct options are 

For the given circuit of $\mathrm{PN}$ - junction diode, which of the following statement is correct-