MCQ SUBJECT

Science & Technology

190 UPSC Prelims MCQs tagged "Science & Technology". Free practice with answer keys, explanations, and timed mock tests on Anantam IAS.

Indian Economy 256 Environment 249 Indian Polity 240 Science & Technology 192 History 184 International Relations 104 Art & Culture 94 Geography 82 Indian Geography 70 Indian Society 57 World Geography 36 CSAT 29 Science & Tech 22 Art and Culture 8 Current Affairs 6 General Studies 4

Consider the following statements regarding the factors affecting glycemic index:
Consider the following statements regarding the factors affecting glycemic index:
1. AOnly 1 and 2
2. BOnly 2 and 3
3. COnly 1 and 3
4. D1, 2 and 3
Answer and explanation
Correct answer: A
Statement 1 is right: higher fibre slows digestion and lowers the glycemic index. Statement 2 is right too, since heavier processing breaks down food structure and pushes the glycemic index up. Statement 3 is wrong because fat tends to slow gastric emptying and glucose absorption rather than speed it up.
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Science & Technology UPSC GPSC-2026 Medium
Which of the following statement/s is/are correct about India’s nuclear energy programme?
Which of the following statement/s is/are correct about India's nuclear energy programme?
1. AOnly 1 and 2
2. BOnly 2 and 3
3. COnly 1 and 3
4. D1, 2 and 3
Answer and explanation
Correct answer: A
Stage 2 of the three-stage programme runs on plutonium-fuelled Fast Breeder Reactors, and Stage 3 is built around the thorium-based Advanced Heavy Water Reactor, so statements 1 and 2 hold. Statement 3 is wrong because Kaiga is not India's first indigenous PHWR; the first home-built PHWR units came up earlier at Rawatbhata (RAPS) in Rajasthan.
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Science & Technology UPSC GPSC-2026 Hard
What does a “Firewall” do?
What does a "Firewall" do?
1. ARemoves viruses from the computer.
2. BFilters data coming and going in the network.
3. CCreates backups of data.
4. DAutomatically encrypts all files.
Answer and explanation
Correct answer: B
A firewall monitors and filters incoming and outgoing network traffic against a set of security rules, acting as a barrier between a trusted internal network and untrusted external ones. Removing viruses is the job of antivirus software, while backups and encryption are separate functions.
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Science & Technology UPSC GPSC-2026 Easy
Consider the following statements regarding the process of measuring blood pressure:
Consider the following statements regarding the process of measuring blood pressure:
1. AOnly 1 and 2
2. BOnly 1 and 3
3. COnly 2 and 3
4. D1, 2 and 3
Answer and explanation
Correct answer: C
Systolic pressure is by definition higher than diastolic (2), and readings genuinely vary across the day with activity, stress and rest (3). Statement 1 is wrong because the arm should rest at heart level, not below it, since a low arm position falsely raises the reading.
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Science & Technology UPSC GPSC-2026 Easy
Consider the following statements regarding the comparison of PNG (Piped Natural Gas) and LPG…
Consider the following statements regarding the comparison of PNG (Piped Natural Gas) and LPG (Liquefied Petroleum Gas):
1. AOnly 1 and 2
2. BOnly 1 and 3
3. COnly 2 and 3
4. D1, 2 and 3
Answer and explanation
Correct answer: B
PNG is mostly methane, which is lighter than air and disperses upward on leakage, while LPG is heavier and pools near the ground, so statement 1 holds. PNG is also supplied at much lower pressure than LPG cylinders, so statement 3 holds. Statement 2 is the trap: the blanket claim that PNG "always" gives more energy per unit weight than LPG is false, since LPG is the more energy-rich domestic fuel.
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Science & Technology UPSC GPSC-2026 Medium
Consider the following statements regarding the scientific aspects of vacuum packing:
Consider the following statements regarding the scientific aspects of vacuum packing:
1. AOnly 1 and 2
2. BOnly 2 and 3
3. COnly 1 and 3
4. D1, 2 and 3
Answer and explanation
Correct answer: B
Statement 1 is wrong because humidity and moisture do affect vacuum-packed food, influencing texture and microbial activity. Statement 2 is correct, since removing oxygen slows oxidation reactions that cause spoilage and rancidity. Statement 3 is also correct, as anaerobic microorganisms can still grow in low-oxygen vacuum conditions, which is why refrigeration is still needed.
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Science & Technology UPSC GPSC-2026 Medium
Why is LED (Light Emitting Diode) technology considered superior to traditional incandescent bulbs?
Why is LED (Light Emitting Diode) technology considered superior to traditional incandescent bulbs?
1. AOnly 1
2. BOnly 2
3. CBoth 1 and 2
4. DNeither 1 nor 2
Answer and explanation
Correct answer: A
Statement 1 is correct: LEDs convert a much higher share of electrical energy into light and waste far less as heat, which makes them far more efficient. Statement 2 is wrong because producing light by heating a metal filament describes the incandescent bulb, not the LED. An LED emits light when current passes through a semiconductor.
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Science & Technology UPSC GPSC-2026 Easy
Consider the following statements regarding electrochemical corrosion:
Consider the following statements regarding electrochemical corrosion:
1. AOnly 1 and 2
2. BOnly 2 and 3
3. COnly 1 and 3
4. D1, 2 and 3
Answer and explanation
Correct answer: C
Moisture or an electrolyte speeds up corrosion by completing the electrochemical circuit, so statement 1 is correct, and galvanic corrosion does occur when two dissimilar metals touch, so statement 3 is correct. Statement 2 is wrong because a purer metal resists corrosion better, while impurities set up local cells that worsen it.
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Science & Technology UPSC GPSC-2026 Medium
Consider the following statements regarding the technical aspects of ethanol blending:
Consider the following statements regarding the technical aspects of ethanol blending:
1. AOnly 1 and 2
2. BOnly 2 and 3
3. COnly 1 and 3
4. D1, 2 and 3
Answer and explanation
Correct answer: B
E20 means a blend of 20% ethanol by volume, not by weight, so statement 1 is wrong. Higher ethanol blends do call for engine and material modifications because ethanol can corrode some components, and ethanol's calorific value is lower than petrol's, so statements 2 and 3 are correct.
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Science & Technology UPSC GPSC-2026 Medium
What is the primary objective of the BharatNet project?
What is the primary objective of the BharatNet project?
1. ATo provide last-mile mobile connectivity through installation of telecom towers in rural areas.
2. BTo connect all Gram Panchayats with high-speed broadband infrastructure using optical fibre network.
3. CTo establish satellite communication exclusively for defence services.
4. DTo establish a satellite-based communication network for remote and border regions.
Answer and explanation
Correct answer: B
BharatNet is the world's largest rural broadband project. Its core aim is to link every Gram Panchayat across India with high-speed broadband by laying an optical fibre cable network, bringing affordable connectivity and e-governance to villages. It isn't a mobile-tower or satellite scheme.
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Science & Technology UPSC GPSC-2026 Easy
Consider the following statements regarding ‘Nano Urea’ recently promoted by the Government of India…
Consider the following statements regarding 'Nano Urea' recently promoted by the Government of India for agricultural use:
1. AOnly 1
2. BOnly 2
3. CBoth 1 and 2
4. DNeither 1 nor 2
Answer and explanation
Correct answer: B
Nano urea is a nitrogen source and does not replace phosphorus and potash fertilizers, so statement 1 is wrong. It delivers much higher nutrient use efficiency than conventional granular urea, which cuts soil degradation and water pollution, making statement 2 correct.
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Science & Technology UPSC GPSC-2026 Medium
Which of the following statement(s) is/are true regarding “FASTag” (RFID technology) used at toll…
Which of the following statement(s) is/are true regarding "FASTag" (RFID technology) used at toll plazas?
1. AOnly 1
2. BOnly 2
3. CBoth 1 and 2
4. DNeither 1 nor 2
Answer and explanation
Correct answer: D
Statement 1 is false — FASTag uses a PASSIVE RFID tag (energised by the reader's signal), not an active, battery-powered tag. Statement 2 is technically weak too: FASTag-style UHF RFID works through electromagnetic fields and radio-wave communication, so calling it 'electromagnetic induction' is imprecise. On a strict reading neither statement is correct → (D). (If the examiner used 'electromagnetic induction' loosely for electromagnetic communication, they might retain (B); but technically (D) is the sounder answer.)
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Science & Technology UPSC GPSC-2026 Medium
In the context of modern healthcare, what is the primary objective of nano-shells or…
In the context of modern healthcare, what is the primary objective of nano-shells or nano-bullets in cancer treatment?
1. ATo strengthen the patient's bone marrow to withstand high doses of traditional chemotherapy.
2. BTo act as a diagnostic tool that changes the colour of the patient's skin in the presence of a tumor.
3. CTo provide targeted drug delivery, ensuring that medication is released only at the site of the cancer cells, thereby minimizing the side effects on healthy tissues.
4. DTo replace the need for surgery by physically vibrating and crushing the tumor using ultrasonic waves.
Answer and explanation
Correct answer: C
Nano-shells and nano-bullets are designed for targeted drug delivery, carrying the medication straight to cancer cells so it acts at the tumour site and spares healthy tissue. This precision is what reduces the broad toxicity seen with conventional chemotherapy. The other options misstate how these nanoparticles work.
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Science & Technology UPSC GPSC-2026 Easy
Which of the following statement(s) is/are true regarding the Integrated Guided Missile Development Programme…
Which of the following statement(s) is/are true regarding the Integrated Guided Missile Development Programme (IGMDP) spearheaded by DRDO?
1. AOnly 1
2. BOnly 2
3. CBoth 1 and 2
4. DNeither 1 nor 2
Answer and explanation
Correct answer: C
The IGMDP produced exactly five missile systems, Prithvi, Agni, Trishul, Akash and Nag, so statement 1 is correct. Nag is a third-generation fire-and-forget anti-tank guided missile that uses an imaging infrared seeker for target lock, so statement 2 is correct too. Both statements hold.
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Science & Technology UPSC GPSC-2026 Medium
Which of the following statements regarding the Indian Space Research Organisation (ISRO) are correct?
Which of the following statements regarding the Indian Space Research Organisation (ISRO) are correct?
1. AOnly 1 and 3
2. BOnly 1 and 2
3. COnly 2 and 3
4. D1, 2 and 3
Answer and explanation
Correct answer: A
ISRO has developed both the PSLV and the GSLV, so statement 1 is correct. Statement 2 is wrong because heavy communication satellites for geostationary orbit are launched by the GSLV, while the PSLV mainly serves polar and sun-synchronous low Earth orbits. Chandrayaan-3 did achieve a soft landing on the Moon, so statement 3 is correct. The right combination is 1 and 3.
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Science & Technology UPSC GPSC-2026 Medium
Which of the following best describes the core operational strategy of the Bhashini Mission…
Which of the following best describes the core operational strategy of the Bhashini Mission launched by the Government of India?
1. AIt is a central database designed to replace English with Hindi as the primary language for all e-governance transactions.
2. BIt is an ecosystem that utilizes a crowdsourcing initiative called 'Bhasha Daan' to collect diverse language datasets to train AI models.
3. CIt is a hardware-based project aimed at distributing indigenous, low-cost smartphones pre-loaded with translation software to rural areas.
4. DIt is a regulatory body established to monitor and censor regional language content on social media platforms.
Answer and explanation
Correct answer: B
Bhashini is India's AI-led language translation platform that builds datasets across Indian languages. Its core strategy relies on a crowdsourcing initiative called 'Bhasha Daan,' where citizens contribute language data used to train AI models for speech and translation. It doesn't replace English with Hindi, distribute hardware, or censor content.
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Science & Technology UPSC GPSC-2026 Medium
Consider the following statements about the Gaganyaan Mission:
Consider the following statements about the Gaganyaan Mission:
1. AOnly 1 and 4
2. BOnly 2 and 4
3. COnly 1 and 3
4. DOnly 2 and 3
Answer and explanation
Correct answer: A
Gaganyaan is a human spaceflight programme to low Earth orbit, not a human lunar journey, so statement 1 is wrong. The first crewed Gaganyaan flight is planned for 2027, so no Indian astronaut has yet flown under Gaganyaan, making statement 4 wrong. HAL builds the crew module structure and other hardware, so statement 3 is correct, and statement 2 is correct. The statements that are not correct are 1 and 4.
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Science & Technology UPSC GPSC-2026 Medium
What is the primary technical objective of the Second Stage of India’s Three-Stage Nuclear…
What is the primary technical objective of the Second Stage of India's Three-Stage Nuclear Power Programme?
1. ATo utilize natural uranium to produce electricity and Plutonium-239.
2. BTo use Fast Breeder Reactors (FBRs) to burn Plutonium-239 and breed more fuel from a Thorium blanket.
3. CTo utilize India's vast Thorium reserves directly in Advanced Heavy Water Reactors (AHWR).
4. DTo focus exclusively on the enrichment of Uranium-235 for export to the global market.
Answer and explanation
Correct answer: B
The second stage uses Fast Breeder Reactors that burn the Plutonium-239 produced in stage one, while a thorium blanket around the core breeds Uranium-233 for the third stage. Option (a) describes the first stage, and direct thorium use in AHWR is the third stage.
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Science & Technology UPSC GPSC-2026 Medium
What role does Electric Propulsion play in the modern Green Space Movement?
What role does Electric Propulsion play in the modern Green Space Movement?
1. AThey eliminate the need for any fuel by using the Earth's magnetic field for propulsion.
2. BThey use solar energy to accelerate ions to very high speeds, providing high fuel efficiency for long-duration missions.
3. CThey are used exclusively for the heavy-lift liftoff phase from the Earth's surface.
4. DThey prevent the formation of space junk by vaporizing defunct satellites using laser beams.
Answer and explanation
Correct answer: B
Electric (ion) propulsion uses solar-generated electricity to ionise a propellant and accelerate the ions to very high exhaust speeds. This delivers very high fuel efficiency, which makes it ideal for long-duration deep-space and station-keeping missions. It produces low thrust, so it can't be used for heavy-lift liftoff from Earth's surface.
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Science & Technology UPSC GPSC-2026 Medium
With reference to ISRO’s achievements in Quantum Communication, which of the following statement(s) is/are…
With reference to ISRO's achievements in Quantum Communication, which of the following statement(s) is/are true?
1. AOnly 1
2. BOnly 2
3. CBoth 1 and 2
4. DNeither 1 nor 2
Answer and explanation
Correct answer: A
ISRO demonstrated free-space Quantum Key Distribution over about 300 metres at the Space Applications Centre in Ahmedabad, including live video conferencing using quantum-key-encrypted signals, so statement 1 is correct. Statement 2 is false because ISRO hasn't established a mainland-to-deep-space satellite quantum link, and India isn't the first country to do so.
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Science & Technology UPSC GPSC-2026 Hard
The first successful test of the Indian-made, helicopter-launched, short-range anti-ship missile was conducted in…
The first successful test of the Indian-made, helicopter-launched, short-range anti-ship missile was conducted in 2026. What is the name of that missile?
1. AAgni
2. BNaval Anti-Ship Missile (Short Range) / NASM-SR
3. CBrahMos
4. DAmogh
Answer and explanation
Correct answer: B
The NASM-SR is India's first indigenously developed air-launched, short-range anti-ship cruise missile. In April 2026, DRDO and the Indian Navy carried out a maiden salvo launch from a Sea King helicopter off the Odisha coast, with both missiles striking the target. Agni is a ballistic missile and BrahMos is a long-range supersonic cruise missile, so they don't fit.
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Science & Technology UPSC GPSC-2026 Medium
In the context of Green Propulsion, which of the following statement(s) is/are true regarding…
In the context of Green Propulsion, which of the following statement(s) is/are true regarding the advantage(s) of using Hydroxylammonium Nitrate (HAN)-based monopropellants over traditional Hydrazine?
1. AOnly 1
2. BOnly 2
3. CBoth 1 and 2
4. DNeither 1 nor 2
Answer and explanation
Correct answer: A
HAN-based green propellants offer higher density and higher specific impulse than hydrazine with much lower toxicity, so statement 1 is correct. Statement 2 is wrong because HAN monopropellants still need a catalyst and a high chamber temperature to decompose and ignite; they don't react spontaneously with the vacuum of space.
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Science & Technology UPSC GPSC-2026 Hard
Which of the following statements regarding the Defence Research and Development Organisation (DRDO) and…
Which of the following statements regarding the Defence Research and Development Organisation (DRDO) and India's missile programme are correct?
1. AOnly 1
2. BOnly 1 and 2
3. COnly 1 and 3
4. D1, 2 and 3
Answer and explanation
Correct answer: B
DRDO developed indigenous missiles under the IGMDP, and the Prithvi is a short-range surface-to-surface ballistic missile, so statements 1 and 2 are correct. The Agni series are surface-to-surface ballistic missiles, not surface-to-air, so statement 3 is wrong.
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Science & Technology UPSC GPSC-2026 Medium
What is the unique significance of the BHAVINI (Bharatiya Nabhikiya Vidyut Nigam Limited) enterprise…
What is the unique significance of the BHAVINI (Bharatiya Nabhikiya Vidyut Nigam Limited) enterprise in India's energy sector?
1. AIt is responsible for the mining and milling of rare earth metals in Gujarat.
2. BIt is the nodal agency for the implementation and operation of Stage-II Fast Breeder Reactors.
3. CIt manages the international civil nuclear cooperation agreements with the US and France.
4. DIt is the research wing of the Department of Atomic Energy (DAE) located in Trombay.
Answer and explanation
Correct answer: B
BHAVINI was set up in 2003 as a special-purpose enterprise under the Department of Atomic Energy specifically to build and operate Stage-II Fast Breeder Reactors, starting with the 500 MWe Prototype Fast Breeder Reactor at Kalpakkam. Rare-earth work falls under bodies like IREL, civil nuclear diplomacy is handled by the DAE and government, and the DAE's Trombay research wing is BARC, so the other options don't fit.
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Science & Technology UPSC GPSC-2026 Medium
Which of the following statement(s) is/are true regarding the PM-WANI (Prime Minister Wi-Fi Access…
Which of the following statement(s) is/are true regarding the PM-WANI (Prime Minister Wi-Fi Access Network Interface) scheme?
1. AOnly 1
2. BOnly 2
3. CBoth 1 and 2
4. DNeither 1 nor 2
Answer and explanation
Correct answer: C
Both statements are correct. PM-WANI lets local shopkeepers and entrepreneurs run public Wi-Fi hotspots without any licence or registration fee from the Department of Telecommunications, so statement 1 holds. Its architecture has exactly four players, Public Data Offices, Public Data Office Aggregators, App Providers and a Central Registry, matching statement 2.
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Science & Technology UPSC GPSC-2026 Medium
With reference to the ‘India Semiconductor Mission’ (ISM), consider the following statements:
With reference to the 'India Semiconductor Mission' (ISM), consider the following statements:
1. AOnly 1
2. BOnly 2
3. CBoth 1 and 2
4. DNeither 1 nor 2
Answer and explanation
Correct answer: C
Both statements are accurate. ISM was set up in 2021 as an independent business division within the Digital India Corporation under MeitY, with administrative and financial autonomy to build a semiconductor and display ecosystem. It explicitly aims to shift India from being a consumer of chips to a producer and an integrated part of the global semiconductor value chain, backed by the Semicon India programme.
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Science & Technology UPSC GPSC-2026 Medium
Which of the following initiatives are primarily aimed at strengthening digital governance and digital…
Which of the following initiatives are primarily aimed at strengthening digital governance and digital public infrastructure in India?
1. AOnly 1 and 2
2. BOnly 2 and 3
3. COnly 1 and 3
4. D1, 2 and 3
Answer and explanation
Correct answer: D
Digital India is the umbrella programme for e-governance and digital service delivery, Aadhaar provides the digital identity layer, and UPI powers instant digital payments. Together they form the backbone of India's Digital Public Infrastructure. All three fit the description.
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Science & Technology UPSC GPSC-2026 Easy
Steel slag can be the material for which of the following? 1. Construction of…
Steel slag can be the material for which of the following? 1. Construction of base road 2. Improvement of agricultural soil 3. Production of cement Select the correct answer using the code given below:
1. A1 and 2 only
2. B2 and 3 only
3. C1 and 3 only
4. D1, 2 and 3 only
Answer and explanation
Correct answer: D
Steel slag can be used for several purposes, and all of the options listed are valid applications.
Statement 1 is correct. Steel slag is a common and cost-effective material for use in road base construction due to its high durability, strength, and drainage properties.
Statement 2 is correct. Crushed steel slag can be used as an amendment for agricultural soil. It can improve drainage, provide some essential nutrients, and even help suppress weeds.
Statement 3 is correct. Steel slag can be partially substituted for some raw materials in cement production, reducing the need for quarrying and lowering the environmental impact of cement manufacturing.
Therefore, the correct answer is 1, 2, and 3.
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Science & Technology UPSC 2020 Medium
Consider the following: 1. Bacteria 2. Fungi 3. Virus Which of the above can…
Consider the following: 1. Bacteria 2. Fungi 3. Virus Which of the above can be cultured in artificial/synthetic medium?
1. A1 and 2 Only
2. B2 and 3 Only
3. C1 and 3 Only
4. D1, 2 and 3
Answer and explanation
Correct answer: A
* Bacteria can be cultured and grown in various artificial culture media, such as nutrient broth, agar plates, or other specific media formulations. Bacteria can metabolize and utilize the nutrients provided in these synthetic culture media to grow and reproduce.
* Fungi can also be cultured in artificial media, such as potato dextrose agar, Sabouraud dextrose agar, or other specialized fungal growth media. Fungi can utilize the organic compounds and nutrients present in these synthetic media to support their growth and development.
* Viruses, on the other hand, are obligate intracellular parasites and cannot be directly cultured in artificial or synthetic media. Viruses require living host cells to replicate and propagate, as they lack the necessary machinery for autonomous growth and reproduction.
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Science & Technology UPSC 2021 Medium
In India, it is legally mandatory for which of the following to report on…
In India, it is legally mandatory for which of the following to report on cybersecurity incidents? 1. Service providers 2. Data centres 3. Body corporate Select the correct answer using the code given below:
1. A1 only
2. B1 and 2 only
3. C3 only
4. D1, 2 and 3
Answer and explanation
Correct answer: D
Statement 1 is Correct: Under Section 70B of the Information Technology Act, 2000, and the CERT-In Rules 2013, service providers are legally required to report cybersecurity incidents to the Indian Computer Emergency Response Team (CERT-In). Statement 2 is Correct: Data centres are explicitly listed as entities that must mandatorily report cybersecurity incidents to CERT-In under the Information Technology (CERT-In) Rules, 2013. Statement 3 is Correct: The IT Act and associated rules mandate that body corporates must report specified types of cybersecurity incidents to CERT-In to ensure national cyber security.
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Science & Technology UPSC 2017 Hard