Question

When a PN junction diode is reverse biased

• A. Electrons and holes are attracted towards each other and move towards the depletion region
• B. Electrons and holes move away from the junction depletion region
• C. Height of the potential barrier decreases
• D. No change in the current takes place

Answer 1

Answer: (B)

1. A p-n junction diode is reverse biased when the n-type region of the diode is connected to the positive terminal of the battery and p-type region is connected to the negative terminal of the battery or cell.
2. 
   
3. ​In the case of reverse biasing, the width of the depletion layer at the junction of the diode increases, which increases the height of the potential barrier.
4. In this case, electrons of the n-region are attracted to the positive terminal of the battery and the holes of the p-region, being positive in nature are attracted to the negative terminal of the battery.
5. Thus, it is clear that in reverse biasing, electron and holes moves away from the depletion layer and it increases the width of the depletion layer.
6. In reverse biasing, a very small current flows due to minority charge carriers that is holes in the n-region and electrons in the p-region.

Thus,

Option D) Electrons and holes move away from the junction depletion region is the correct option.