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. Al types of UAVs can use battery only as a source of power supply. How many of the statements given above are correct?

1. A. Only one
2. B. Only two
3. C. All the three
4. D. None

Answer: D

Explanation

Statement I is incorrect. Not all UAVs can perform vertical landing. Fixed-wing drones, for instance, require a runway or net for landing and cannot hover or land vertically. Statement II is also incorrect for the same reason; fixed-wing drones cannot hover. Automated hovering is characteristic of multirotor drones (like quadcopters) and some hybrid VTOL (Vertical Take-Off and Landing) designs, but not all UAVs. Statement III is incorrect because many UAVs, especially high-endurance military or long-range models, cannot rely solely on batteries due to power and endurance limitations. They often use fuel-based engines or hybrid systems. The energy density of batteries is generally lower than that of fuels, making them unsuitable for all UAV applications. The increasing use of drones in various sectors, including defense, surveillance, and logistics, makes their technological capabilities a relevant topic for UPSC.