Quantum Computing
Science & Technology
- PYQs8
- Articles1
Background
Quantum computing represents a paradigm shift in computational power with potential to revolutionize various sectors like defense, healthcare, finance, and scientific research. UPSC expects candidates to understand such disruptive technologies, their underlying principles, applications, challenges, and India's initiatives in the field.
Quantum computing is an emerging field that harnesses the principles of quantum mechanics, such as superposition and entanglement, to perform computations. Unlike classical computers that use bits representing 0 or 1, quantum computers use qubits which can exist in multiple states simultaneously, enabling them to solve complex problems intractable for traditional supercomputers.
Facts & tables
- Fundamental Unit
- Uses qubits instead of classical bits, leveraging superposition and entanglement.
- Potential Applications
- Materials simulation, cryptography, logistics optimization, climate modeling, drug discovery.
- Major Challenge
- Dealing with 'noise and errors' (decoherence) due to qubit sensitivity and environmental interaction.
- Error Correction
- Techniques are being developed to create 'logical qubits' from multiple physical qubits to reduce error rates.
| Feature | Classical Bit | Quantum Qubit |
|---|---|---|
| State | 0 or 1 (at any time) | 0, 1, or superposition of both |
| Fundamental Unit | Bit | Qubit |
| Processing Power | Sequential | Massively parallel (due to superposition & entanglement) |
| Sensitivity | Less sensitive | Highly sensitive (prone to decoherence) |
| Type | Reference |
|---|---|
| Conceptual area | Emerging Information Technologies |
| Conceptual area | Physics & Materials Science |
| Body | Role |
|---|---|
| Google Quantum AI | Researches/develops |
| IBM | Researches/develops |
| Department of Science & Technology (India) | Funds/promotes |
Prelims angle
Prelims angle: Statement-based questions
Prelims angle: Factual recall
- Quantum computing leverages quantum mechanics (superposition, entanglement) for computation.
- Qubits are fundamental units, unlike classical bits.
- Promises breakthroughs in materials science, cryptography, and AI.
- Major hurdle: decoherence and error rates in Noisy Intermediate-Scale Quantum (NISQ) devices.
- Error correction techniques are crucial for building fault-tolerant quantum computers.
| Year | Framing tags |
|---|---|
| 2026 | Multi-statement analysis, Factual recall |
| 2026 | Multi-statement analysis, Factual recall |
| 2026 | Multi-statement analysis, Conceptual understanding |
| 2026 | Statement-based questions, Factual recall |
| 2025 | Statement-based questions, Factual recall |
| 2025 | Statement-based questions, Factual recall |
| 2022 | Terminology-based question, Factual recall |
| 2020 | Multi-statement analysis, Conceptual understanding |
Timeline
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Emerging Information Technologies
Conceptual area
-
Physics & Materials Science
Conceptual area
-
Prelims 2020
Multi-statement analysis, Conceptual understanding
-
Prelims 2022
Terminology-based question, Factual recall
-
Prelims 2025
Statement-based questions, Factual recall
-
Prelims 2025
Statement-based questions, Factual recall
-
Prelims 2026
Multi-statement analysis, Factual recall
-
Prelims 2026
Multi-statement analysis, Factual recall
-
Prelims 2026
Multi-statement analysis, Conceptual understanding
-
Prelims 2026
Statement-based questions, Factual recall
-
The quantum computing age will only begin when we silence the noise
Quantum computing uses quantum mechanics principles (superposition, entanglement) with qubits to solve complex problems beyond classical computers. Key applications are simulation, cryptography, and optimization. Major challenges include decoherence and error correction, which researchers are addressing to achieve fault-tolerant quantum computers.
See also
Past papers
2020–2026 · 7 questions
In the news
The quantum computing age will only begin when we silence the noise
Quantum computing uses quantum mechanics principles (superposition, entanglement) with qubits to solve complex problems beyond classical computers. Key applications are simulation, cryptography, and optimization. Major challenges include decoherence and error correction, which researchers are addressing to achieve fault-tolerant quantum computers.
Try these PYQs
Consider the following statements:
I. It is expected that Majorana 1 chip will enable quantum computing.
II. Majorana 1 chip has been introduced by Amazon Web Services (AWS).
III. Deep learning is a subset of machine learning.
Which of the statements given above are correct?
Majorana 1 chip is linked to quantum computing and deep learning is part of machine learning, but AWS did not introduce the Majorana 1 chip. * ✅ I. Majorana 1 chip – Expected to advance quantum computing. * ❌ II. AWS introducing Majorana 1 – Incorrect, it’s a Microsoft project. * ✅III. Deep learning – A subset of machine learning. Only statements I and III are correct.
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:
Statement 1 is Correct: The National Quantum Mission (NQM) aims to develop intermediate-scale quantum computers with 50 to 1000 physical qubits within 8 years. Specifically, it targets 50–100 physical qubits in 5 years and scales up to 50–1000 physical qubits in 8 years using platforms like superconducting and photonic technology. Statement 2 is Correct: The implementation of the mission explicitly includes the establishment of four Thematic Hubs (T-Hubs) in top academic and national R&D institutes across India. These hubs focus on distinct technology verticals: Quantum Computing (led by IISc Bengaluru), Quantum Communication (led by IIT Madras), Quantum Sensing & Metrology (led by IIT Bombay), and Quantum Materials & Devices (led by IIT Delhi). Therefore, both statements are correct.
With the present state of development, Artificial Intelligence an effectively do which of the following?
1. Bring down electricity consumption in industrial units.
2. Create meaningful short stories and songs.
3. Disease diagnosis.
4. Text-to-Speech Conversion.
5. Wireless transmission of electrical energy.
Select the correct answer using the code given below:
* AI is now being used to analyze industrial data, optimize processes, and predict energy usage patterns. This allows for targeted interventions to reduce overall consumption. * AI can now generate more creative and coherent text formats compared to 2020. While still under development, some AI-generated content can be quite engaging, blurring the lines between human and machine creation. * AI has become a powerful tool in medical diagnosis. AI algorithms can analyze vast amounts of medical data, identify complex patterns, and assist healthcare professionals in diagnosis and treatment planning. * Text-to-speech conversion using AI continues to be a well-established technology. AI can now generate natural-sounding speech with various accents and emotions, making it a valuable tool for various applications. * While significant wireless transmission of electricity over long distances remains a challenge, there has been progress in short-range wireless charging and localized energy transfer using AI-powered systems. Note: From the current status of AI development, all the listed applications of AI are feasible. However, this question was asked by the UPSC in 2020 when Generative AI was yet to become mainstream. UPSC's official answer key gave 'B' as the correct answer.
Which of the following statements regarding the features of blockchain technology are correct?
1. Records stored in the database may be made visible to relevant stakeholders without risk of alteration.
2. Copies of the entire database are stored on multiple computers on a network, syncing within seconds.
3. Consortium blockchain is a blend of public and private blockchains allowing selective data access.
4. Mathematical algorithms make it impossible to change or delete any data once recorded and accepted.
Select the answer using the code given below:
Statement 1 is Correct: Blockchain's architecture allows data to be shared transparently with relevant stakeholders. Because the ledger is append-only and secured by network consensus, users can view records without the risk of unauthorized alteration. Statement 2 is Correct: Blockchain operates as a decentralized database (Distributed Ledger Technology). Identical copies of the entire ledger are stored across multiple computers (nodes) on a network. These nodes continuously communicate and sync rapidly (often within seconds, depending on the specific blockchain protocol) to maintain a single source of truth. Statement 3 is Correct: A consortium blockchain is a hybrid model that blends features of both public (open) and private (closed) blockchains. It is governed by a pre-approved group of organizations rather than a single entity or the open public, allowing for semi-decentralized control and selective data access. Statement 4 is Correct: Blockchain uses complex mathematical algorithms (cryptographic hashing) to link blocks. Once data is recorded and validated by the network, changing or deleting it requires altering all subsequent blocks and gaining majority network control, making tampering practically impossible. *Note: While all four statements are factually correct based on the principles of blockchain technology, there is no option provided that includes all of them (1, 2, 3, and 4). Option C is the most comprehensive and appropriate choice as it correctly identifies statements 1, 2, and 4 as a valid set.* Therefore, the correct option is C.
Consider the following statements about Mission Sudarshan Chakra of India:
1. It aims to enhance India's air defence, ballistic missile defence and aerial offensive capabilities.
2. This Mission is being designed to enhance rapid, precise, and powerful defence responses, reinforcing India's strategic autonomy.
3. One of the aims of this Mission is to cover all public places of India by an expanded nationwide security shield by 2035.
Which of the statements given above is/are correct?
Statement 1 is Correct: Mission Sudarshan Chakra is designed as a multi-domain security umbrella. It explicitly aims to enhance India's air defence, ballistic missile defence, and aerial offensive capabilities, acting as both a defensive shield and an offensive sword. Statement 2 is Correct: The mission integrates advanced technologies like AI, space-based sensors, and directed energy weapons to ensure rapid, precise, and powerful defence responses. This indigenous development (incorporating projects like Project Kusha) is specifically aimed at reinforcing India's strategic autonomy and self-reliance in the defence sector. Statement 3 is Correct: A major distinguishing feature of this initiative is its expanded scope. Announced as a 10-year national security initiative, a stated goal of the mission is to bring all public places (including hospitals, railways, and religious/cultural sites) under an expanded nationwide security shield by 2035, moving beyond the conventional protection of just military and strategic installations. Therefore, the correct option is A.
Show 3 more PYQs
GPS-Aided Geo Augmented Navigation (GAGAN) uses a system of ground stations to provide necessary augmentation. Which of the following statements is/are correct in respect of GAGAN?
I. It is designed to provide additional accuracy and integrity.
II. It will allow more uniform and high quality air traffic management.
III. It will provide benefits only in aviation but not in other modes of transportation.
Select the correct answer using the code given below.
✅ Statement I: Correct
*GAGAN is an Indian SBAS developed by ISRO and AAI to enhance GPS accuracy and integrity, crucial for aviation safety.* ✅ Statement II: Correct
*It improves GPS reliability and accuracy, enabling better air traffic management and safer, efficient navigation.* ❌ Statement III: Incorrect
*GAGAN’s benefits extend beyond aviation to railways, roadways, maritime, agriculture, and disaster management.* Correct Answer: Only Statements I and II are correct.
Which one of the following-is the context in which the term "qubit" is mentioned?
- A qubit is the fundamental unit of information in quantum computing, analogous to the bit in classical computing. - However, unlike a bit that can only be either 0 or 1, a qubit can exist in a superposition of both states simultaneously. - This property of qubits allows quantum computers to perform certain calculations much faster than traditional computers.
Which one of the following pairs of semiconductor plants in India and their locations is **not** correctly matched?
| Semiconductor Plant | Location |
|---|---|
| (a) CG Power and Industrial Solutions Pvt. Ltd. in partnership with Renesas Electronics and STARS Microelectronics | Gujarat |
| (b) Tata Semiconductor Assembly and Test Pvt. Ltd. | Assam |
| (c) HCL-Foxconn Joint Venture India Chip Ltd. | Madhya Pradesh |
| (d) SicSem Pvt. Ltd. | Odisha |
Option A is correctly matched: The Union Cabinet approved the Outsourced Semiconductor Assembly and Test (OSAT) facility by CG Power and Industrial Solutions (in partnership with Renesas Electronics and STARS Microelectronics) to be set up in Sanand, Gujarat. Option B is correctly matched: Tata Semiconductor Assembly and Test Pvt. Ltd. (TSAT) is establishing a greenfield semiconductor assembly and test facility in Jagiroad, Assam. It marks a major industrial investment in Northeast India. Option C is incorrectly matched: The OSAT facility by the HCL-Foxconn Joint Venture (India Chip Pvt. Ltd.) is being established in Jewar, Uttar Pradesh (in the Yamuna Expressway Industrial Development Authority region), not Madhya Pradesh. It will manufacture display driver chips. Option D is correctly matched: SicSem Pvt. Ltd. is setting up a Silicon Carbide (SiC) semiconductor manufacturing plant in Bhubaneswar, Odisha. It is designed to be India's first commercial compound semiconductor fab. Therefore, Option C is the correct answer.