Question

In unbiased p-n junction diode

• A. the potential is same everywhere.
• B. there is an electric field at the junction directed from the p-type side to the n-type side.
• C. there is an electric field at the junction directed from the $n$-type side to $p$-type side.
• D. the p-type side is at higher potential than the n-type side.

Hint:

$n$-type has positive ions, $p$-type has negative ions; field always goes $+$ to $-$.

Answer 1

The Correct Option is C

Step 1: Concept
In a p-n junction, diffusion of electrons and holes creates a depletion region with immobile ions.

Step 2: Meaning
The $n$-side gets positive ions and $p$-side gets negative ions.

Step 3: Analysis
An electric field is established pointing from positive to negative. Since the $n$-side is positive and $p$-side is negative, the field points from $n$ to $p$.

Step 4: Conclusion
This internal electric field creates a potential barrier that opposes further diffusion. Final Answer: (C)