Question

Two identical pn junctions may be connected in series, with a battery in three ways as shown in figure. The potential drops across the two pn junctions are equal in :

• A. circuit 1 and 3
• B. circuit 2 and 3 only
• C. circuit 1 only
• D. All the circuit

Answer 1

Answer: (B)

circuit 2 and 3 only

In circuit 2, each p-n junction is forward biased,hence same current flows giving same potential difference across p-n junction.

In circuit 3, each p-n junction is reverse biased, and due to the flow of same leakage current, giving equal potential difference across p-n junction.