UPSC Mains Previous Year Questions 2021: GS3 Science & Technology | Science & Technology for UPSC CSE PDF Download

Q1:  How is S-400 air defense system technically superior to any other system presently available in the world? (Science & Technology) 
Ans: 

S-400 Triumf Missile System: The S-400 Triumf is a mobile surface-to-air missile system developed by Russia, known as the most advanced and dangerous long-range SAM in the world. India is in talks with Russia to purchase five of these systems.

Unique Features:

• Advanced Capabilities: The S-400 can track and neutralize various threats like aircraft, missiles, and UAVs simultaneously, making it highly versatile.
• Varied Missiles and Ranges: Each system comprises missiles with ranges spanning 40 km to 400 km and altitudes up to 30 km, forming a layered air defense network.
• Differences from Other Systems:
  • Unlike THAAD, which fires a single type of missile up to 150-200 km, the S-400 offers varied missiles and ranges.
  • THAAD can't intercept fighter jets, unlike the S-400.
  • Deployment time for S-400 is 5 minutes, compared to 25 minutes for Patriot systems.
  • S-400 has a maximum target speed of 4.8 km/sec, while Patriot's is 1.38 km/sec.

Impact and Controversy: Despite criticism from the US under the CAATSA agreement for purchasing the S-400 from Russia, India's decision was inevitable due to security concerns with its neighboring nations.

Q2: What are the research and developmental achievements in applied biotechnology? How will these achievements help to uplift the poorer sections of the society? (Science & Technology)
Ans: 

Biotechnology Overview: Biotechnology, rooted in biology, leverages cellular and biomolecular processes to develop solutions benefiting human life and the environment. Harnessing nature's toolkit and genetic makeup, it contributes to healing the world.

Research and Development Achievements:

• Stem Cell Research: Stem cells possess infinite division ability and can differentiate into various body cells, offering potential for specific cell programming.
• Human Genome Project: This international initiative aimed to map human DNA, enabling identification of disease-causing genes.
• Targeted Cancer Therapies: Unlike standard chemotherapies, these therapies minimize damage to healthy cells by specifically targeting cancerous cells or interfering with specific molecules.
• CRISPR: CRISPR, a novel gene-editing system, holds promise in medical research, including applications in HIV research.

Role in Uplifting Society's Marginalized Sections:

• Agricultural Impact: Biotechnology boosts crop yield, resilience to climate and pests, aiding marginal farmers.
• Medical Advancements: It revolutionizes medical science, reducing mortality rates and offering quality treatment within India.
• Genome Sequencing: Facilitating health assessments across India, enabling targeted policy initiatives by the government.
• Food Preservation: Enhances food product shelf life, contributing to price control for the underprivileged.
• Pollution Control: Biotechnology helps alleviate suffering by reducing pollution, such as cleaning landfills through bioremediation techniques.

Q3: 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? (Science & Technology)
Ans: 

Understanding LEDs: LEDs function as semiconductors emitting light when activated. White light, commonly used, is a combination of red, green, and blue light. The challenge in making blue LEDs was significant, and its invention earned the Nobel Prize in Physics 2014 for Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura.

Impact on Daily Life:

• Electricity Conservation: Modern white LED bulbs efficiently convert over 50% of electricity into light, a vast improvement over incandescent bulbs at 4%.
• Enhancing Access to Electricity: High efficiency makes LED lighting valuable in regions lacking electricity. Solar-charged LED lamps offer long-lasting illumination.
• Smart Energy-Saving Homes: LEDs can incorporate sensors for smart home features, detecting occupancy and automatically turning off lights in empty rooms.
• Facilitating Technological Progress: LEDs are crucial in backlighting LCDs in devices like smartphones, laptops, and televisions, offering energy efficiency and thin displays.
• Enhanced Data Storage: Blue LED lasers in Blu-ray players allow storing significantly more data compared to DVD players, expanding data storage capabilities.

Future Applications of LEDs: Researchers are exploring LEDs for data transmission over the Internet and water purification. These advancements hint at continued significant impacts on human life.