General Studies 2021 GS Paper III 15 marks 250 words Compulsory Explain

Q16

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? (Answer in 250 words)

हिंदी में प्रश्न पढ़ें

वर्ष 2014 में भौतिक विज्ञान में नोबेल पुरस्कार संयुक्त रूप से आकासाकी, अमानो तथा नाकामुरा को 1990 के दशक में नीली एल.ई.डी. के आविष्कार के लिए प्रदान किया गया था । इस आविष्कार ने मानव-जाति के दैनंदिन जीवन को किस प्रकार प्रभावित किया है ? (250 शब्दों में उत्तर दीजिए)

Evaluate your answer to this question → See all 2021 General Studies questions

Directive word: Explain

This question asks you to explain. The directive word signals the depth of analysis expected, the structure of your answer, and the weight of evidence you must bring.

See our UPSC directive words guide for a full breakdown of how to respond to each command word.

How this answer will be evaluated

Approach

The directive 'explain' requires demonstrating causal linkages between the Blue LED invention and its transformative effects on daily life. Structure: brief technical context (why blue LED was the 'Holy Grail') → sector-wise everyday impacts (lighting, displays, health, environment) → concluding with future implications or India's context.

Key points expected

Technical significance: blue LED enabled white light through phosphor coating, completing the RGB spectrum for full-color displays
Energy-efficient lighting revolution: 85% less energy than incandescent bulbs, 10x lifespan, impacting household electricity bills and national energy consumption
Digital display proliferation: smartphones, LED TVs, laptops, advertising screens—ubiquitous in modern communication and entertainment
Health and sanitation applications: UV-LED water purification systems, medical equipment sterilization, phototherapy for neonatal jaundice
Environmental impact: reduced carbon emissions globally; India's UJALA scheme distributing 36+ crore LED bulbs saving 47,000 crore kWh
Emerging applications: Li-Fi technology, smart agriculture (LED grow lights), and precision medical treatments

Evaluation rubric

Dimension	Weight	Max marks	Excellent	Average	Poor
Demand-directive understanding	20%	3	Clearly distinguishes between the invention itself and its downstream impacts; addresses 'everyday life' specifically rather than general technological advancement; connects physics innovation to tangible daily experiences	Mentions impacts but mixes invention details with effects; partially addresses everyday relevance; some drift into general LED history	Describes the Nobel winners or LED physics without explaining everyday impacts; confuses blue LED with generic LED technology; ignores the 'human beings' focus
Content depth & accuracy	20%	3	Covers multiple sectors (lighting, displays, health, environment) with accurate technical details; mentions specific 1990s timeline; explains why blue was critical (gallium nitride, p-type doping challenge)	Covers 2-3 sectors superficially; minor technical inaccuracies; mentions energy efficiency without quantification; omits why blue LED was the breakthrough	Factual errors (e.g., confusing with laser diodes, wrong materials, incorrect energy savings); limited to one sector; generic statements like 'LEDs save energy'
Structure & flow	20%	3	Logical progression from technical basis → domestic lighting → digital devices → health/environment → future outlook; smooth transitions between sectors; 250-word discipline maintained	Recognizable structure but uneven weightage; some abrupt jumps; word count slightly off; conclusion feels tagged on	Disorganized listing without thematic grouping; no clear introduction or conclusion; significantly over/under word limit; repetitive points
Examples / case-law / data	20%	3	Includes India-specific data: UJALA scheme statistics, SLNP (Street Light National Programme), domestic manufacturing under Make in India; global data like IEA estimates on energy savings; specific products (smartphones, TV backlighting)	Generic mention of 'energy saving' without numbers; one Indian example; common knowledge examples without specificity	No Indian context; no quantitative data; purely theoretical treatment; examples from unrelated technologies
Conclusion & analytical edge	20%	3	Forward-looking synthesis: emerging applications (Li-Fi, vertical farming, circadian lighting); critical reflection on e-waste challenges from rapid obsolescence; connects to India's energy security and climate commitments	Summary restatement of points; generic positive closing; no critical dimension or future orientation	No conclusion; abrupt ending; purely descriptive without synthesis; irrelevant philosophical closing unrelated to the question

Practice this exact question

Write your answer, then get a detailed evaluation from our AI trained on UPSC's answer-writing standards. Free first evaluation — no signup needed to start.

Evaluate my answer →