Science & Tech · Robotics & Autonomous Systems
The concept being tested: UAV technical capabilities (vertical landing, hovering, power supply).
With reference to Unmanned Aerial Vehicles (UAVs), consider the following statements: I. All types of UAVs can do vertical landing. II. All types of UAVs can do automated hovering. III. All types of UAVs can use battery only as a source of power supply. How many of the statements given above are correct?
UAVs are not one uniform aircraft design; the family includes fixed-wing UAVs, rotary-wing (multicopter/helicopter-type) UAVs and hybrid VTOL designs, and each type has different flight and power characteristics. This is exactly what defeats all three statements, since each one uses the sweeping qualifier "all types". Vertical landing and automated hovering belong to rotary-wing and hybrid VTOL UAVs, but fixed-wing UAVs need continuous forward airspeed to generate lift, so they cannot hover and must land using a runway, catapult launch, or net or parachute recovery instead of landing vertically. Power supply is equally varied: alongside battery-electric UAVs, many designs use internal combustion or hybrid-electric engines, fuel cells, or solar cells for long-endurance high-altitude platforms. Since not one of the three claims is true across every UAV type, the correct count of correct statements is zero, which is why "None" is the official answer.
What UPSC was testing
The entire trap sits in the qualifier "all types" attached to each statement; UPSC is testing whether aspirants know UAVs form a diverse family, fixed-wing, rotary-wing and hybrid VTOL, rather than a single design, so any blanket claim about them collapses the moment one counter-example type is considered.
How often this comes up
This concept has appeared 4 times in UPSC Prelims General Studies Paper I between 2015 and 2025 — in 2018, 2020 and 2025.
The option-by-option autopsy for this question — why each of the other three is wrong, and which neighbouring concept each one was built from — is in the app.
Other past-year questions touching Robotics & Autonomous Systems.