In an unbiased $p$ - $n$ junction

• A

  potential at $p$ is more than that at $n$
• Correct answer
  B

  potential at $p$ is less than that at $n$
• C

  potential at $p$ is equal to that at $n$
• D

  potential at $p$ is + ve and that at $n$ is - ve

Solution

An unbiased $p$ - $n$ junction is shown below.

From the diagram, it is clear that in depletion region, $n$-side has immobile positive charge, whereas $p$-side has immobile negative charge. Therefore, potential at $n$ is less than that of $n$.

Hence, the correct answer is option: 'B'.