UPSC (Prelims) 2025 Science & Technology Previous Year Questions

With reference to 'Direct Air Capture', an emerging technology, which of the following statements is/are correct?
I. It can be used as a way of carbon sequestration.
II. It can be a valuable approach for plastic production and in food processing.
III. In aviation, it can be a source of carbon for combining with hydrogen to create synthetic low-carbon fuel.

Select the correct answer using the code given below.

Consider the following types of vehicles:
I. Full battery electric vehicles
II. Hydrogen fuel cell vehicles
III. Hybrid electric vehicles

How many of the above are considered as alternative powertrain vehicles?

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?

In the context of electric vehicle batteries, consider the following elements:
I. Cobalt
II. Graphite
III. Lithium
IV. Nickel

How many of the above usually make up battery cathodes?

Consider the following substances:
I. Ethanol
II. Nitroglycerine
III. Urea

Coal gasification technology can be used in the production of how many of them?

What is the common characteristic of the chemical substances generally known as CL-20, HMX and LLM-105, which are sometimes talked about in media?

Consider the following statements:
I. It is expected that Majorana 1 chip will enable quantum computing.
II. Majorana 1 chip has been introduced by Amazon Web Services (AWS).
III. Deep learning is a subset of machine learning.

Which of the statements given above are correct?

With reference to monoclonal antibodies, often mentioned in news, consider the following statements:
I. They are man-made proteins.
II. They stimulate immunological function due to their ability to bind to specific antigens.
III. They are used in treating viral infections like that of Nipah virus.

Which of the statements given above are correct?

Consider the following statements:
I. No virus can survive in ocean waters.
II. No virus can infect bacteria.
III. No virus can change the cellular transcriptional activity in host cells.

How many of the statements given above are correct?

Consider the following statements:
Statement I: Activated carbon is a good and an attractive tool to remove pollutants from effluent streams and to remove contaminants from various industries.
Statement II: Activated carbon exhibits a large surface area and a strong potential for adsorbing heavy metals.
Statement III: Activated carbon can be easily synthesised from environmental wastes with high carbon content.

Which one of the following is correct in respect of the above statements?

Consider the following statements:
Statement I: Some rare earth elements are used in the manufacture of flat television screens and computer monitors.
Statement II: Some rare earth elements have phosphorescent properties.

Which one of the following is correct in respect of the above statements?

Consider the following space missions:
I. Axiom
II. SpaDex
III. Gaganyaan

How many of the space missions given above are encouraged and supported to conduct microgravity research?

Artificial way of causing rainfall to reduce air pollution makes use of

GPS-Aided Geo Augmented Navigation (GAGAN) uses a system of ground stations to provide necessary augmentation. Which of the following statements is/are correct in respect of GAGAN?
I. It is designed to provide additional accuracy and integrity.
II. It will allow more uniform and high quality air traffic management.
III. It will provide benefits only in aviation but not in other modes of transportation.