🔬 Science & TechnologyUPSC 2011Space & Space Technology

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 semiconductor material.2. The average lifespan 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?

a1 only
b2 and 3 only
c1 and 3 only
d1, 2 and 3
✓ Correct answer: c) 1 and 3 only
ExplanationStatement 1 is correct: An LED is a type of semiconductor light source with two leads.It is a p-n junction diode, which when turned on emits light.A fluorescent lamp is a low-pressure mercury-vapour gas-discharge light.In a CFL, an electric current is driven through a tube containing argon and a small amount of mercury vapor.This generates invisible ultraviolet light that excites a fluorescent coating (called phosphor) on the inside of the tube, which then emits visible light.Statement 2 is incorrect: LED bulbs are much more efficient than CFL bulbs in terms of power consumption and life years.Statement 3 is correct: LED bulbs consume less power as compared to CFL.LED bulbs are expensive as compared to CFL bulbs.LED bulbs are much more efficient than CFL bulbs.206

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