What is the difference between a CFL and an LED lamp?

1. To produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semi-conductor material.

2. The average life span of a CFL is much longer than that of an LED lamp.

3. A CFL is less energy-efficient as compared to an LED lamp.

Which of the statements given above is/are correct?

Question

Question

This question was previously asked in

Official UPSC Civil Services Exam 2011 Prelims Part A

Answer 1

The correct answer is 1 and 3.

Key Points

Difference between the CFL and LED bulb:
- The primary difference between the CFL and LED bulb is that LED bulbs are more durable and has a long life. Hence, statement 2 is incorrect.
- LED bulb consumes less power as compared to CFL.
- LED bulbs are expensive as compared to CFL bulbs.
- LED bulbs are much more efficient than CFL bulbs. Hence, statement 3 is correct.
CFL bulbs are made up of argon and mercury in small quantities.
- In a CFL, an electric current is driven through a glass tube containing argon and a small amount of mercury vapour. This generates invisible ultraviolet light that excites a fluorescent coating (called phosphor) on the inside of the tube, which then emits visible light.
The main semiconductor materials used to manufacture LEDs are:
- Indium gallium nitride (InGaN): blue, green, and ultraviolet high-brightness LEDs.
- Aluminium gallium indium phosphide (AlGaInP): yellow, orange, and red high-brightness LEDs.
- Aluminium gallium arsenide (AlGaAs): red and infrared LEDs. Hence, statement 1 is correct.