QUESTION 16
GS3
15 marks
The Nobel Prize in Physics of 2014 was jointly awarded to Akasaki, Amano and Nakamura for the invention of Blue LEDs in 1990s. How has this invention impacted the everyday life of human beings?
WRITE IN
11 min
250 words
What the examiner wants
Explain how the invention of blue LEDs changed daily life.
ExplainMake clear how and why it happens: causes, process, and an example for each point.
Demand-wise check
- 1Why blue mattered: with red and green, enabled white light and full-colour displays≈50 words
- 2Effects: energy-efficient white LED lighting, smartphone and TV screens, Blu-ray, UV LEDs for water purification≈50 words
- 3Energy and climate: less electricity, longer life, solar-powered lamps for off-grid homes≈50 words
- 4India: UJALA programme≈50 words
Open in about 30 words and close in about 30.
Answer plan
Why blue LEDs were a breakthroughApplicationsEnergy and social impactIndia exampleConclusion
Where marks usually go
- Explaining LED physics without everyday impacts
- No India link
Draw this
- RGB combination sketch producing white light
Value addition
- ProgrammeUJALA distributed over 36 crore LED bulbs, saving an estimated 47 billion kWh a year.EESL / Ministry of Power
- FactLEDs use about 75% less energy and last up to 25 times longer than incandescent bulbs.US Department of Energy
Next: plan for one minute, write it in 11 minutes, then get it checked.