Question

Two identical p-n junctions may be connected in series with battery in three ways as shown in the adjoining figure. The potential drop across the p-n junctions are equal in

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

Answer 1

The correct option is C Circuit 2 and circuit 3

The current will flow from $p$ to $n$ junctions,

In circuit $1,$ the currents are in opposite directions for $p-n$ junction. So the potential drop can not be equal.

In a circuit, $2$ and circuit $3$, the currents in the $p-n$ junctions are in same directions and they are similar. So the potential drops across the $p-n$ junctions will be equal.

Therefore option $C$ is correct.