UPSC Prelims 2011 · GS Paper I: A new optical disc format known as the Blu-ray Disc (BD) is becoming popular.…
A new optical disc format known as the Blu-ray Disc (BD) is becoming popular. In what way is it different from the traditional DVD ?
- 1. DVD supports Standard Definition video while BD supports High Definition video.
- 2. Compared to a DVD, the BD format has several times more storage capacity.
- 3. Thickness of BD is 2.4 mm while that of DVD is 1.2 mm.
Which of the statements given above is/are correct ?
Answer (b) & explanation
Statements 1 and 2 are correct (b). A Blu-ray disc is read by a blue-violet laser (405 nm) with a shorter wavelength than a DVD's red laser, so data packs more tightly: about 25 GB per layer against 4.7 GB on a DVD. That gives several times more storage (2) and room for High Definition video, while DVD is mainly standard definition (1). Statement 3 is wrong: both discs are 1.2 mm thick; Blu-ray's data layer just sits nearer the surface. So (a), (c) and (d) fail.
Notice the trend: Ultra HD Blu-ray stores up to 100 GB for 4K video, but streaming has largely replaced discs. Trap: '2.4 mm' doubles the real thickness.
Answer as per the official UPSC answer key.
Same theme in UPSC Mains
- MAINS UPSC Mains 2024 · GS Paper IV · Q7There is a technological company named ABC Incorporated which is the second largest worldwide, situated in the Third World. You are the Chief Executive Officer and…
- MAINS UPSC Mains 2026 · GS Paper III · Q9Explain how fake news and disinformation pose threat to Internal Security and Public Order in Indian context? In this regard, discuss salient features of amendments in…
- MAINS UPSC Mains 2024 · GS Paper II · Q7Poverty and malnutrition create a vicious cycle, adversely affecting human capital formation. What steps can be taken to break the cycle?
Related questions from other years
Consider the following statements with regard to involvement of private entities in India’s space programme :
- 1. The Indian National Space Promotion and Authorisation Centre (IN-SPACe) is an autonomous agency formed to facilitate participation of private entities.
- 2. Agnikul Cosmos launched the world’s first flight using 3D-printed rocket engine.
- 3. Skyroot Aerospace has developed liquid fuel for GSLV.
Which of the statements given above is/are correct ?
Answer (c) & explanation
Statements 1 and 2 are correct (c). Statement 1 is right: IN-SPACe (2020) is the single-window, autonomous body under the Department of Space that authorises private space activity. Statement 2 is right: Agnikul's Agnibaan SOrTeD (May 2024) flew on the world's first single-piece 3D-printed semi-cryogenic engine. Statement 3 is wrong: Skyroot builds its own Vikram rockets; it does not make fuel for ISRO's GSLV. So options (a), (b) and (d) fail.
Notice Skyroot's milestone: Vikram-S (2022) was India's first privately built rocket to reach space. The Indian Space Policy, 2023 opened all space activities to private firms, and 100% FDI is allowed in parts of the sector. NSIL is ISRO's commercial arm.
Answer as per the official UPSC answer key.
Which of the following statements with regard to drone swarms is/are correct ?
- 1. They use Terahertz band of frequency to communicate with the command centre.
- 2. Individual drones in the swarm can communicate with other drones in the swarm.
- 3. GPS Spoofing is a commonly used technique to counter drone swarm attack.
Select the answer using the code given below :
Answer (b) & explanation
Statements 2 and 3 are correct (b). Statement 2 is right: in a swarm, the drones talk to each other and share tasks, so the group keeps working even if some are lost. Statement 3 is right: defenders often jam or spoof GPS to send them off course. Statement 1 is wrong: swarms usually use ordinary radio bands; terahertz links are still experimental and short-range. So options (a), (c) and (d) fail.
Notice other counters: laser weapons, like DRDO's directed-energy systems, anti-drone guns and net systems. India showed a 75-drone swarm at the 2021 Army Day parade. Drone wars in Ukraine and during Operation Sindoor (2025) showed how cheap drones can overwhelm costly defences.
Answer as per the official UPSC answer key.
Which of the following statements with regard to GenomeIndia Project is/are correct ?
- 1. It is a part of the Human Genome Project.
- 2. The project is funded by the Department of Biotechnology (DBT), Government of India.
- 3. Its primary aim is to build a catalogue of genetic diversity of the Indian population.
Select the answer using the code given below :
Answer (b) & explanation
Statements 2 and 3 are correct (b). Statement 2 is right: GenomeIndia (2020) is funded by the Department of Biotechnology. Statement 3 is right: it sequenced 10,000 genomes from many Indian communities to build a catalogue of the country's genetic variation, and the data was released in 2025. Statement 1 is wrong: the international Human Genome Project was a separate effort that ended in 2003. So options (a), (c) and (d) fail.
Notice the uses: finding gene variants behind diseases common in India, such as sickle cell and thalassaemia, and building personalised medicine. The data is stored at the Indian Biological Data Centre in Faridabad. A larger follow-up aims to sequence one million genomes.
Answer as per the official UPSC answer key.
Which of the following statements with regard to the National Quantum Mission (NQM) is/are correct ?
- 1. It aims at developing intermediate-scale quantum computers with 50-1000 physical qubits.
- 2. Its implementation includes setting up of four Thematic Hubs (T-Hubs) in academic and national R&D institutes across India.
Select the answer using the code given below :
Answer (c) & explanation
Both statements are correct (c). Statement 1 is right: the National Quantum Mission (2023, under the DST) aims at quantum computers of 50–1,000 physical qubits within eight years. Statement 2 is right: it has four T-Hubs: computing at IISc Bengaluru, communication at IIT Madras, sensing and metrology at IIT Bombay, and materials and devices at IIT Delhi. So options (a), (b) and (d) fail.
Notice the budget: about ₹6,000 crore from 2023-24 to 2030-31. The mission also aims at secure quantum communication over 2,000 km between cities, and satellite-based quantum links. India joined a handful of nations, like the USA, China and France, with such a dedicated mission.
Answer as per the official UPSC answer key.
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