What is the difference between a CFL and an LED lamp? To produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semi-conductor material. The average life span of a CFL is much longer than that of an LED lamp. A CFL is less energy-efficient as compared to an LED lamp. Which of the statements given above is/are correct?

Technology : Electronics And Green Technology

Q 30 / 38

UPSC CSE Prelims 2011

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

To produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semi-conductor material.
The average life span of a CFL is much longer than that of an LED lamp.
A CFL is less energy-efficient as compared to an LED lamp.

Which of the statements given above is/are correct?

EXPLANATION

The correct option is 1 and 3 only.

Explanation

Compact Fluorescent Lamps (CFLs) and Light Emitting Diode (LED) lamps differ in their working principles, efficiency, and lifespan.

Statement 1: Correct.
A CFL produces light by passing electric current through mercury vapour, which emits ultraviolet radiation that excites a phosphor coating to produce visible light. An LED lamp produces light using semiconductor materials through electroluminescence.
Statement 2: Incorrect.
LED lamps have a significantly longer lifespan than CFLs. Therefore, it is incorrect to state that CFLs last longer than LEDs.
Statement 3: Correct.
CFLs are less energy-efficient compared to LED lamps. LEDs consume less electricity for the same light output and have higher energy efficiency.

Key Takeaway: LEDs use semiconductor technology, are more energy-efficient, and have a longer lifespan compared to CFLs, which rely on mercury vapour and phosphor coating.