Question

In the figure, the numbers 1, 2, 3 represent barrier potential ($V_o$) of a p-n junction under forward bias

• A. 1 - high voltage battery 2 - without battery 3 - low voltage bettery
• B. 1 - high voltage battery, 2 - low voltage battery, 3 - without battery
• C. 1 - without battery, 2 - low voltage battery, 3 - high voltage battery
• D. 1 - low voltage battery 2 - without battery 3 - high voltage bettery

Answer 1

The correct option is C 1 - without battery, 2 - low voltage battery, 3 - high voltage battery

If a forward bias voltage is applied to a p-n junction diode with a barrier potential $V_o$, the effective potential reduces to $(V_o-V)$. More is the forward bias voltage, more the potential reduces.

So, in

1. Barrier potential remains same, so the battery is not connected externally.
2. Low voltage battery is connected externally.
3. High voltage battery is connected externally.