Question

In a p-n junction diode, what happens to the width of the depletion layer under reverse bias?

• A. It decreases
• B. It increases
• C. It remains constant
• D. It becomes zero

Hint:

Forward bias → depletion region decreases. Reverse bias → depletion region increases.

Answer 1

The Correct Option is B

Concept: A p-n junction diode contains a depletion region near the junction where mobile charge carriers are absent. This region forms due to recombination of electrons and holes.
Step 1: Effect of reverse bias.} In reverse bias, the positive terminal of the battery is connected to the n-side and the negative terminal to the p-side. This pulls electrons and holes away from the junction.
Step 2: Resulting change in depletion region.} Since carriers move away from the junction, the depletion region expands and the potential barrier increases.
Step 3: Conclusion.} Therefore, under reverse bias, the width of the depletion layer increases.