Question

The colour of light emitted by LED depends on:

• A. Its reverse bias
• B. The amount of forward current
• C. Its forward bias
• D. Type of semiconductor material

Answer 1

The correct option is D

Type of semiconductor material

The explanation for the correct option:
Option D:

1. The full form of LEDs is light-emitting diodes.
2. These are the semiconductor devices that convert electrical energy into light energy.
3. The color of the light emitted by an LED depends upon the wavelength of light.
4. This wavelength depends upon the type of semiconductor material used in the LED.
5. Thus, the color of light emitted by an LED depends on the type of semiconductor material.

The explanation for the incorrect options:
Option A:

1. If an LED is in reverse bias, this means that it is off.
2. So reverse bias is not related to the color of the LED.

Option B:

1. The amount of forwarding current only changes the intensity of light.
2. So it has no relation to the color emitted by the LED.

Option C:

1. If an LED is in forwarding bias, this means that it is on.
2. But it has nothing to do with the color of the LED.

Hence, the correct answer is option D.