Special Purpose Diodes question from MHT CET 2023 (13 May, Shift 1)

Answer: (d)

1. The curve lies in the first quadrant: positive $V$, positive current in mA, rising sharply (exponentially).
2. This is the forward-bias curve of a p-n junction; an LED is a p-n diode operated in forward bias.
3. A solar cell curve lies in the fourth quadrant and reverse curves of a Zener or photodiode have negative $V$ and $I$.
4. So the answer is (d) forward bias characteristics of an LED.