Explanation
- A
Only one
Only one. None of the three universal claims holds for every UAV type.
- B
Only two
Only two. Vertical landing, hovering and battery-only each fail for some UAV class.
- C
All the three
All three. Fixed-wing UAVs cannot land vertically or hover, and many long-endurance UAVs are not battery-only.
- D
None
None. I fails (fixed-wing recovery). II fails (no hover without rotary/VTOL lift). III fails (fuel and hybrid UAVs exist). No statement is universally true.
Summary. Official Set A key is (d) none. ‘All types of UAVs’ is the trap. Fixed-wing drones need a strip, catapult or net; they cannot land vertically or hover. Rotary and some VTOL types can. Battery-only is true of small multirotors, not of HALE or many military airframes that burn liquid fuel. So I, II and III are all over-claims. The official count is zero correct statements.
Same topic · past papers
UPSC has asked this before
These previous-year questions sit on the same topic. Open one to practise the earlier ask.
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2023 · Q60 · General Studies · 2 marks
With reference to green hydrogen, Consider the following statements : 1. It can be used directly as a fuel for internal combustion. 2. It can be blended with natural gas and used as fuel for heat or power generation. 3. It can be used in the hydrogen fuel cell to run vehicles. How many of the above statements are correct?