2025 GS Paper I, all questions

UPSC Prelims 2025 · GS Paper I

Question 42: Science and Technology

With reference to Unmanned Aerial Vehicles (UAVs), consider the following statements :

  1. IAll types of UAVs can do vertical landing.
  2. IIAll types of UAVs can do automated hovering.
  3. IIIAll 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 the three
dNone

AnswerThe answer is (d).

UAVs come in many types, so a claim about all of them fails. Fixed-wing UAVs take off and land on runways, by catapult, net or parachute, and cannot land vertically or hover; only multirotor and some hybrid vertical take-off types can. Larger UAVs run on piston or jet engines burning fuel, and some use solar or hybrid power, so not all are battery-only. None of the three statements is correct.

  • I. Fixed-wing UAVs land on runways or by net or parachute, not vertically.
  • II. Fixed-wing UAVs cannot hover.
  • III. Many UAVs use fuel engines, solar or hybrid power.

How you could have got this

No shortcut here: in a “how many” question, ruling out options doesn’t help. Every statement has to be judged.

The red flag in statement I is “all”. In UPSC’s papers, statements with “all” were true 41% of the time (76 statements). A hint, not a rule.

The red flag in statement II is “all”. In UPSC’s papers, statements with “all” were true 41% of the time (76 statements). A hint, not a rule.

The red flag in statement III is “only”. In UPSC’s papers, statements with “only” were true 27% of the time (82 statements). A hint, not a rule.

The red flag in statement III is “all”. In UPSC’s papers, statements with “all” were true 41% of the time (76 statements). A hint, not a rule.

This follows an unofficial answer: UPSC has not published its key for this year, and if that answer is wrong, so is this path.

Which options go is worked out from UPSC’s key and the options, not by a model.

Why each option is right or wrong
  • (a) Wrong: none of the three claims holds for all UAVs.
  • (b) Wrong: none of the three claims holds for all UAVs.
  • (c) Wrong: fixed-wing and fuel-driven UAVs break all three claims.
  • (d) Right: fixed-wing UAVs cannot hover or land vertically, and many are not battery-powered.

Explanation: written by UPSC Grade, not by UPSC.

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Source: UPSC, Civil Services (Preliminary) Examination 2025, General Studies Paper I, Series A. The paper on upsc.gov.in.