1. What is the value of knee voltage for a Yellow LED light?

2. Calculate the value of Planck’s constant for blue LED, for its knee voltage.

3. Calculate the wavelength of IR LED by comparing with Red LED at their corresponding knee voltage.

4. Calculate the value of IR LED by comparing with Green LED at their corresponding knee voltage.

5. Calculate the wavelength of IR LED by drawing a graph between voltage and wavelength.

6. What happens when an LED is directly connected to a power supply? Which is the most suitable value of resistor if a power supply of     0-12 V is used?

7. Which LED has the largest energy gap?