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Q1Science·Space Science and AstronomyPYQ 2026
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?
- A1 only
- B2 and 3 only
- C1 and 2 onlyCorrect
- D1, 2 and 3
Why the other options are incorrect
- Option A
Statement 1 correctly identifies IN-SPACe’s role in enabling and authorising private space activity. It misses statement 2, which the key accepts with reference to Agnikul’s flight using a single-piece 3D-printed engine.
- Option B
Statement 2 is accepted, but statement 3 wrongly attributes GSLV fuel development to Skyroot. Skyroot is associated with its Vikram launch-vehicle programme, whereas GSLV is an ISRO vehicle. Statement 1 should be included instead.
- Option D
The incorrect Skyroot–GSLV claim in statement 3 invalidates this combination. Keep the organisations and achievements separate: IN-SPACe enables private participation, Agnikul demonstrated the single-piece printed engine, and Skyroot developed Vikram vehicles.
Q2Science·Space Science and AstronomyPYQ 2025
With reference to Unmanned Aerial Vehicles (UAVs), consider the following statements:
1. All types of UAVs can do vertical landing.
2. All types of UAVs can do automated hovering.
3. All types of UAVs can use battery only as a source of power supply.
How many of the statements given above are correct?
- AOnly one
- BOnly two
- CAll three
- DNoneCorrect
Explanation
Correct. Fixed-wing UAVs cannot do vertical landing or automated hovering, and many UAVs use internal combustion engines or hybrid power, not batteries alone.
Why the other options are incorrect
- Option A
None of the statements is universally true for all types of UAVs.
- Option B
Fixed-wing UAVs cannot hover or land vertically, and many UAVs use fuel engines, so none of the statements holds for all types.
- Option C
Fixed-wing UAVs require runways; many large UAVs use combustion engines. None of the three statements applies universally.
Q3Science·Space Science and AstronomyPYQ 2025
Consider the following space missions:
1. Axiom-4
2. SpaDeX
3. Gaganyaan
How many of the space missions given above encourage and support micro-gravity research?
- AOnly one
- BOnly two
- CAll threeCorrect
- DNone
Explanation
Correct. Axiom-4 conducts micro-gravity experiments on the ISS, SpaDeX demonstrates docking for future space station modules, and Gaganyaan is India's crewed mission with micro-gravity research payloads.
Why the other options are incorrect
- Option A
All three missions involve or support micro-gravity research environments, not just one.
- Option B
All three missions, not just two, are designed to support micro-gravity experiments in space.
- Option D
All three missions have micro-gravity research as a significant component of their objectives.
Q4Science·Space Science and AstronomyPYQ 2024
Consider the following statements:
Statement-I: Giant stars live much longer than dwarf stars.
Statement-II: Compared to dwarf stars, giant stars have a greater rate of nuclear reactions.
Which one of the following is correct in respect of the above statements?
- ABoth Statement-I and Statement-II are correct and Statement-II explains Statement-I
- BBoth Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
- CStatement-I is correct, but Statement-II is incorrect
- DStatement-I is incorrect, but Statement-II is correctCorrect
Explanation
Correct. Giant stars have higher nuclear reaction rates (Statement-II is true) but this causes them to exhaust fuel faster, giving them shorter, not longer, lifespans (Statement-I is false).
Why the other options are incorrect
- Option A
Statement-I is actually incorrect; giant stars burn fuel faster and have shorter lifespans despite their larger mass.
- Option B
Statement-I is wrong. Giant stars consume their nuclear fuel at much higher rates than dwarf stars and die sooner.
- Option C
Statement-II is correct; massive stars have far higher core temperatures and nuclear reaction rates.
Q5Science·Space Science and AstronomyPYQ 2023
Consider the following pairs:
Objects in space : Description
1. Cepheids — Giant clouds of dust and gas in space
2. Nebulae — Stars which brighten and dim periodically
3. Pulsars — Neutron stars that are formed when massive stars run out of fuel and collapse
How many of the above pairs are correctly matched?
- AOnly oneCorrect
- BOnly two
- CAll three
- DNone
Explanation
Correct. Only pair 3 is correct. Cepheids are variable stars (not dust clouds), nebulae are gas-dust clouds (not variable stars), and pulsars are indeed rapidly rotating neutron stars formed from collapsed massive stars.
Why the other options are incorrect
- Option B
Pairs 1 and 2 have their descriptions swapped; Cepheids are variable stars and nebulae are gas-dust clouds.
- Option C
Pairs 1 and 2 are incorrectly matched; their descriptions are interchanged.
- Option D
Pair 3 is correctly matched; pulsars are neutron stars that emit beams of radiation as they rotate.
Q6Science·Space Science and AstronomyPYQ 2023
Which one of the following countries has its own Satellite Navigation System?
- AAustralia
- BCanada
- CIsrael
- DJapanCorrect
Explanation
Correct. Japan operates the Quasi-Zenith Satellite System (QZSS), a regional satellite navigation system that augments GPS coverage over Japan and the Asia-Oceania region.
Why the other options are incorrect
- Option A
Australia does not operate its own satellite navigation system; it relies on GPS and augmentation systems.
- Option B
Canada does not have an indigenous satellite navigation constellation.
- Option C
Israel has advanced satellite capabilities but does not operate an independent navigation system.
Q7Science·Space Science and AstronomyPYQ 2022
If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth?
1. GPS and navigation systems could fail.
2. Tsunamis could occur at equatorial regions.
3. Power grids could be damaged.
4. Intense auroras could occur over much of the Earth.
5. Forest fires could take place over much of the planet.
6. Orbits of the satellites could be disturbed.
7. Shortwave radio communication of aircraft flying over polar regions could be interrupted.
Select the correct answer using the code given below:
- A1, 2, 4 and 5 only
- B2, 3, 5, 6 and 7 only
- C1, 3, 4, 6 and 7 onlyCorrect
- D1, 2, 3, 4, 5, 6 and 7
Explanation
Correct. Solar storms can disrupt GPS, damage power grids via geomagnetically induced currents, trigger intense auroras, alter satellite orbits through atmospheric drag, and interrupt polar shortwave radio. They do not cause tsunamis or forest fires.
Why the other options are incorrect
- Option A
Solar storms do not cause tsunamis or widespread forest fires; these are unrelated geophysical and terrestrial events.
- Option B
Tsunamis and forest fires are not caused by solar storms. However, GPS failure (1) and auroras (4) are valid effects.
- Option D
Tsunamis (2) are caused by seismic events, and large-scale forest fires (5) are not a consequence of solar storms.
Q8Science·Space Science and AstronomyPYQ 2022
Which one of the following statements best reflects the idea behind the 'Fractional Orbital Bombardment System' often talked about in media?
- AA hypersonic missile is launched into space to counter an asteroid approaching the Earth and explode it in space
- BA spacecraft lands on another planet after making several orbital motions
- CA missile is put into a stable orbit around the Earth and deorbits over a target on the EarthCorrect
- DA spacecraft moves along a comet with the same speed and places a probe on its surface
Explanation
Correct. A Fractional Orbital Bombardment System places a nuclear warhead into low Earth orbit and then de-orbits it onto a target, making its trajectory harder to predict than a conventional ICBM.
Why the other options are incorrect
- Option A
FOBS is a weapons delivery system, not a planetary defence mechanism against asteroids.
- Option B
FOBS is a military concept involving Earth orbit, not interplanetary travel or landing.
- Option D
This describes a cometary rendezvous mission like Rosetta, not a weapons delivery system.
Q9Science·Space Science and AstronomyPYQ 2021
Which one of the following is a reason why astronomical distances are measured in light-years?
- ADistances among stellar bodies do not change
- BGravity of stellar bodies does not change
- CLight always travels in straight line
- DSpeed of light is always sameCorrect
Explanation
Correct. The speed of light in vacuum is a universal constant (~3 × 10⁸ m/s), making it a reliable and invariant standard for defining large astronomical distances.
Why the other options are incorrect
- Option A
Stellar distances do change over time due to proper motion; this is not why light-years are used.
- Option B
Gravitational constancy is irrelevant to the choice of distance unit.
- Option C
Light bends near massive objects due to gravity; it does not always travel in a straight line.
Q10Science·Space Science and AstronomyPYQ 2020
"The experiment will employ a trio of spacecraft flying in formation in the shape of an equilateral triangle that has sides one million kilometres long, with lasers shining between the craft." The experiment in question refers to:
- AVoyager-2
- BNew Horizons
- CLISA Pathfinder
- DEvolved LISACorrect
Explanation
Correct. Evolved LISA (eLISA/LISA) is a space-based gravitational wave observatory using three spacecraft in a triangular formation with million-kilometre laser arms to detect gravitational waves.
Why the other options are incorrect
- Option A
Voyager-2 is a single spacecraft on an interstellar trajectory, not a formation-flying experiment.
- Option B
New Horizons is a Pluto flyby mission, not a laser interferometry experiment.
- Option C
LISA Pathfinder was a single-spacecraft technology demonstrator, not the full three-spacecraft constellation described.
Q11Science·Space Science and AstronomyPYQ 2019
Recently, scientists observed the merger of giant black holes billions of light-years away from the Earth. What is the significance of this observation?
- A'Higgs boson particles' were detected
- B'Gravitational waves' were detectedCorrect
- CPossibility of inter-galactic space travel through 'wormhole' was confirmed
- DIt enabled the scientists to understand 'singularity'
Explanation
Correct. The LIGO and Virgo observatories detected gravitational waves produced by the merger of black holes, confirming a key prediction of Einstein's general theory of relativity.
Why the other options are incorrect
- Option A
The Higgs boson was detected at CERN using particle accelerators, not through astronomical observations of black hole mergers.
- Option C
No wormhole was confirmed; the observation detected gravitational wave signals from the merger event.
- Option D
While black holes contain singularities, the observation's primary significance was the direct detection of gravitational waves.
Q12Science·Space Science and AstronomyPYQ 2019
For the measurement/estimation of which of the following are satellite images/remote sensing data used?
1. Chlorophyll content in the vegetation of a specific location
2. Greenhouse gas emissions from rice paddies of a specific location
3. Land surface temperatures of a specific location
Select the correct answer using the code given below:
- A1 only
- B2 and 3 only
- C3 only
- D1, 2 and 3Correct
Explanation
Correct. Remote sensing satellites use spectral bands to measure vegetation chlorophyll (NDVI), thermal sensors for land surface temperatures, and methane-detecting instruments for greenhouse gas emissions from specific areas.
Why the other options are incorrect
- Option A
Satellites can also measure greenhouse gas concentrations and land surface temperatures using infrared and thermal sensors.
- Option B
Chlorophyll content is routinely measured by remote sensing using spectral reflectance data in the visible and near-infrared bands.
- Option C
Remote sensing can also estimate chlorophyll content and methane emissions from rice paddies, not just surface temperature.