Question

The depletion region of p-n junction

• A. increases if reverse biased.
• B. increases if forward biased.
• C. decreases if reverse biased.
• D. remains same in reverse and forward biasing.

Hint:

Reverse bias pulls charge carriers away from the junction, so the depletion region widens.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
The depletion region is the layer near the p-n junction that has no free charge carriers, only fixed ions.

Step 2: Reverse bias
The positive terminal of the battery goes to the n side and the negative terminal to the p side. Free electrons and holes are pulled away from the junction, so more fixed ions are exposed and the depletion region increases. This is option (A).

Step 3: Forward bias
The carriers are pushed towards the junction and fill in part of the depletion layer. So the region shrinks, which is why (B) and (D) do not hold.

Step 4: Check
Statement (C) says it decreases when reverse biased, which is the reverse of what happens.

Final Answer:
Reverse bias pulls carriers away from the junction and widens the depletion region, option (A). \[ \boxed{\text{Increases if reverse biased}} \]