Question

When a forward bias is applied to a p-n junction. It ______.

• A. raises the potential barrier
• B. lowers the potential barrier
• C. reduces the majority carrier current to zero
• D. none of the above

Hint:

\textbf{Forward Bias} = Lower Barrier = Narrow Depletion Layer = High Current.
\textbf{Reverse Bias} = Higher Barrier = Wide Depletion Layer = Negligible Current.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
In forward biasing, the positive terminal of the battery is connected to the p-side and the negative terminal to the n-side.
Step 2: Formula Application:
The applied voltage $V$ opposes the built-in potential barrier $V_B$. The effective barrier height becomes $(V_B - V)$.
Step 3: Explanation:
This reduction in the potential barrier allows majority carriers (holes from p-side and electrons from n-side) to diffuse across the junction, resulting in a large current.
Step 4: Final Answer:
It lowers the potential barrier.