UPSC Prelims Practice Questions — DRDO conducts successful ground test of full scale actively cooled long duration Scramjet Engine for Hypersonic Missile Programme

Q1. Among the following jet propulsion systems, which one is uniquely designed to sustain combustion while the airflow passing through the engine remains at supersonic speed?

  • A. Turbojet
  • B. Ramjet
  • C. Scramjet
  • D. Turbofan

Q2. Consider the following statements about propulsion systems: 1. A ramjet has no rotating mechanical compressor or turbine. 2. A scramjet sustains combustion in a supersonic airstream. 3. A turbojet relies solely on the vehicle's forward motion to compress incoming air, without any mechanical compressor. 4. A rocket engine carries its own oxidiser and does not depend on atmospheric oxygen. Which of the above statements is/are NOT correct?

  1. A ramjet has no rotating mechanical compressor or turbine.
  2. A scramjet sustains combustion in a supersonic airstream.
  3. A turbojet relies solely on the vehicle's forward motion to compress incoming air, without any mechanical compressor.
  4. A rocket engine carries its own oxidiser and does not depend on atmospheric oxygen.
  • A. 1 and 2
  • B. 2 and 4
  • C. 3 only
  • D. 1 and 4

Q3. In the context of India's hypersonic programme, the Hypersonic Technology Demonstrator Vehicle (HSTDV) is best described as which one of the following?

  • A. A rocket-boosted, scramjet-powered cruise vehicle built to demonstrate air-breathing hypersonic propulsion in flight
  • B. A ballistic missile carrying a hypersonic glide vehicle as its re-entry payload
  • C. A reusable launch vehicle for placing small satellites into low-Earth orbit
  • D. A ground-based hypersonic wind tunnel for testing engine components

Q4. With reference to the 2020 HSTDV flight test and India's November 2024 hypersonic missile flight-trial, consider the following statements: 1. The 2020 HSTDV flight validated sustained scramjet combustion in flight for about 20 seconds, whereas the November 2024 event was India's first long-range hypersonic missile flight-trial. 2. The hypersonic missile flight-tested in November 2024 was designed to carry payloads for ranges greater than 1,500 km. 3. Both the 2020 HSTDV and the November 2024 hypersonic missile were launched from Hyderabad. Which of the statements given above is/are correct?

  1. The 2020 HSTDV flight validated sustained scramjet combustion in flight for about 20 seconds, whereas the November 2024 event was India's first long-range hypersonic missile flight-trial.
  2. The hypersonic missile flight-tested in November 2024 was designed to carry payloads for ranges greater than 1,500 km.
  3. Both the 2020 HSTDV and the November 2024 hypersonic missile were launched from Hyderabad.
  • A. 1 only
  • B. 1 and 2 only
  • C. 2 and 3 only
  • D. 1, 2 and 3

Q5. The full-scale actively cooled scramjet combustor ground tests for India's Hypersonic Cruise Missile Programme are led by which one of the following DRDO laboratories?

  • A. Research Centre Imarat (RCI)
  • B. Defence Research & Development Laboratory (DRDL)
  • C. Advanced Systems Laboratory (ASL)
  • D. Defence Metallurgical Research Laboratory (DMRL)

Q6. The Defence Research and Development Organisation (DRDO), which conducted the scramjet engine ground tests, functions under which one of the following?

  • A. Department of Defence Production, Ministry of Defence
  • B. Department of Defence Research and Development, Ministry of Defence
  • C. Department of Science and Technology, Ministry of Science and Technology
  • D. Department of Military Affairs, Ministry of Defence

Q7. With the successful 2020 flight test of the HSTDV demonstrating air-breathing scramjet technology in flight, India became which nation to achieve this capability?

  • A. Second
  • B. Third
  • C. Fourth
  • D. Fifth

Q8. In the DRDO scramjet engine, the indigenously developed 'endothermic' liquid hydrocarbon fuel is significant primarily because it:

  • A. Absorbs heat by chemically cracking into lighter hydrocarbons, cooling the engine before combustion
  • B. Ignites spontaneously on contact with atmospheric oxygen, removing the need for any igniter
  • C. Carries its own oxidiser, eliminating the need for atmospheric air during combustion
  • D. Solidifies at high temperature to form a protective thermal barrier on the combustor wall

Q9. Consider the following statements about DRDO's 2026 full-scale scramjet combustor tests: 1. The full-scale combustor was ground-tested for over 12 minutes on 09 January 2026. 2. A subsequent test on 09 May 2026 achieved a run-time of over 1,200 seconds. 3. The tests were conducted at the Scramjet Connect Pipe Test (SCPT) Facility in Hyderabad. 4. The May 2026 test was a flight-trial conducted off the Odisha coast. Which of the above statements is/are NOT correct?

  1. The full-scale combustor was ground-tested for over 12 minutes on 09 January 2026.
  2. A subsequent test on 09 May 2026 achieved a run-time of over 1,200 seconds.
  3. The tests were conducted at the Scramjet Connect Pipe Test (SCPT) Facility in Hyderabad.
  4. The May 2026 test was a flight-trial conducted off the Odisha coast.
  • A. 1 and 2
  • B. 3 only
  • C. 2 and 3
  • D. 4 only

Q10. With reference to DRDO's scramjet combustor ground tests, consider the following statements: 1. The January 2026 full-scale test ran for over 700 seconds, while the May 2026 test nearly doubled this to over 1,200 seconds. 2. The April 2025 test at the Scramjet Connect Test Facility was of a subscale combustor run for over 1,000 seconds. 3. The May 2026 full-scale test was shorter in duration than the January 2026 full-scale test. Which of the statements given above is/are correct?

  1. The January 2026 full-scale test ran for over 700 seconds, while the May 2026 test nearly doubled this to over 1,200 seconds.
  2. The April 2025 test at the Scramjet Connect Test Facility was of a subscale combustor run for over 1,000 seconds.
  3. The May 2026 full-scale test was shorter in duration than the January 2026 full-scale test.
  • A. 1 only
  • B. 1 and 2 only
  • C. 2 and 3 only
  • D. 1, 2 and 3

Q11. Consider the following descriptions of missile categories: 1. Cruise missile — an air-breathing, self-propelled missile that flies within the atmosphere along a low, level path. 2. Ballistic missile — rocket-powered only during its initial boost phase, thereafter following an unpowered arcing trajectory. 3. Scramjet-powered hypersonic missile — a cruise-type missile that sustains air-breathing propulsion at hypersonic speeds. 4. Hypersonic glide vehicle — a satellite placed in low-Earth orbit that later glides back to a ground target. Which of the above are correctly identified?

  1. Cruise missile — an air-breathing, self-propelled missile that flies within the atmosphere along a low, level path.
  2. Ballistic missile — rocket-powered only during its initial boost phase, thereafter following an unpowered arcing trajectory.
  3. Scramjet-powered hypersonic missile — a cruise-type missile that sustains air-breathing propulsion at hypersonic speeds.
  4. Hypersonic glide vehicle — a satellite placed in low-Earth orbit that later glides back to a ground target.
  • A. 1, 2 and 3
  • B. 1 and 4 only
  • C. 2, 3 and 4
  • D. 1, 2, 3 and 4

Q12. Among the following, which is the only Indian missile system developed as a joint venture with Russia and fielded as a supersonic cruise missile?

  • A. Agni-Prime
  • B. BrahMos
  • C. Pralay
  • D. Nirbhay