Question

I - V characteristics of LED is shown correctly by graph

• A. d
• B. b
• C. a
• D. c

Hint:

LEDs have higher threshold voltages ($1.8\text{V}$ to $3\text{V}$) compared to Silicon diodes ($0.7\text{V}$).

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
An LED is a special p-n junction diode that emits light when forward-biased. Its I-V characteristics are similar to a normal diode but with a higher knee voltage.
Step 3: Detailed Explanation:
LEDs are operated exclusively in forward bias to produce light through radiative recombination of carriers.
The characteristic graph for an LED is strictly in the first quadrant (forward bias).
Graph (d) shows the typical non-linear exponential increase of current after reaching a specific threshold (knee) voltage in the first quadrant.
Step 4: Final Answer:
Graph (d) correctly represents the I-V characteristics of an LED.