Question

In the depletion region of a diode,

• A. there are no mobile charges
• B. equal number of holes and electrons exist, making the region neutral
• C. recombination of holes and electrons has taken place
• D. immobile charged carrier ions exist

Answer 1

Answer: (A), (B), (D)

The correct options are
A there are no mobile charges
B equal number of holes and electrons exist, making the region neutral
D immobile charged carrier ions exist

In a p-n junction diode, as a result of electron-hole recombination, only an equal number of holes and electrons exists, and a small region near the junction is depleted from free charge carriers and only immovable ions remain there. This region is known as the depletion layer.

Hence, the correct options are (A), (B) and (D).

(Basically, electron-hole recombination is the cause of the depletion layer. It does not take place in the depletion layer)