UPSC Prelims Previous Year Questions 2024: Science and Technology | Science & Technology for UPSC CSE PDF Download

Ans: (c) Metaverse

The term "Metaverse" is used to describe an interoperable network of 3D virtual worlds that can be accessed simultaneously by millions of users. In the metaverse, users can interact with each other and the digital environment in real-time, often through avatars. Additionally, the metaverse allows users to exert property rights over virtual items, meaning they can own, buy, sell, and trade digital assets within these virtual worlds. This concept integrates various technologies, including virtual reality (VR), augmented reality (AR), and blockchain, to create a seamless and immersive experience.

In contrast:

• Big data analytics refers to the process of examining large and varied data sets to uncover hidden patterns, unknown correlations, and other useful information.
• Cryptography is the practice of secure communication in the presence of third parties.
• Virtual matrix is not a standard term commonly used to describe such a network of virtual worlds.

Hence, the correct answer is (c) Metaverse.

Ans: (b) 2 and 3 only

1. RTGs are miniature fission reactors.
   This statement is incorrect. RTGs are not fission reactors. Instead, they generate electricity through the decay of radioactive isotopes, typically Plutonium-238. Fission reactors generate power through nuclear fission, which is a different process.

2. RTGs are used for powering the onboard systems of spacecraft.
   This statement is correct. RTGs have been widely used in space missions to provide reliable power for spacecraft, particularly in environments where solar power is not feasible, such as deep space.

3. RTGs can use Plutonium-238, which is a by-product of weapons developments.
   This statement is correct. Plutonium-238 is produced in nuclear reactors and can be a by-product of the production of weapons-grade plutonium.

Thus, the correct statements are 2 and 3, making the correct answer (b) 2 and 3 only.

Ans: (d) Statement I is incorrect, but Statement II is correct.

Statement I: Giant stars live much longer than dwarf stars.
This statement is incorrect. Giant stars have shorter lifespans compared to dwarf stars. Giant stars burn through their nuclear fuel much more quickly due to their higher mass and greater rate of nuclear reactions.

Statement II: Compared to dwarf stars, giant stars have a greater rate of nuclear reactions.
This statement is correct. Giant stars have a much greater rate of nuclear reactions than dwarf stars because of their larger masses and higher core temperatures.

Therefore, Statement I is incorrect, but Statement II is correct, making the correct answer (d) Statement I is incorrect, but Statement II is correct.

Ans: (a) Nitric oxide

Ans: (b) Only two

1. Identification of narcotics on passengers at airports or in aircraft: Radars are not typically used for this purpose. Instead, this activity relies on other technologies such as X-ray scanners, metal detectors, and chemical detection methods like sniffer dogs or ion mobility spectrometry.

2. Monitoring of precipitation: Radars are widely used for this purpose. Weather radars can detect precipitation, its intensity, and movement, which helps in forecasting weather conditions.

3. Tracking the migration of animals: Radars can be used to track the migration of animals, particularly birds. These are known as radar ornithology, where radars detect the movement of flocks of birds during migration.

Thus, radars can be used for activities 2 and 3, making the correct answer (b) Only two.

Ans: (d) None

• Rafale: The Dassault Rafale is a 4.5-generation fighter aircraft.
• MiG-29: The Mikoyan MiG-29 is a 4th-generation fighter aircraft.
• Tejas MK-1: The HAL Tejas MK-1 is also considered a 4th-generation fighter aircraft.

None of these aircraft are classified as fifth-generation fighter aircraft. Fifth-generation fighter aircraft, such as the F-22 Raptor and F-35 Lightning II, feature advanced stealth capabilities, integrated avionics, and superior performance characteristics.

Ans: (d) 1,2 and 3

1. Controlled drug delivery in patients: Hydrogels are widely used in the medical field for controlled drug delivery. They can encapsulate drugs and release them at a controlled rate, making them ideal for various therapeutic applications.

2. Mobile air-conditioning systems: Hydrogels are not typically used in mobile air-conditioning systems. These systems generally rely on refrigerants and other technologies to provide cooling.

3. Preparation of industrial lubricants: Hydrogels are not commonly used in the preparation of industrial lubricants. Industrial lubricants are typically composed of oils, greases, and other chemical additives designed to reduce friction and wear in machinery.

Therefore, hydrogels are primarily used in controlled drug delivery, making the correct answer (a) 1 only.

Ans: (d) Water Vapour

Ans: (c) Long duration energy storage.

Pumped-storage hydropower is a type of hydroelectric power generation used for long-duration energy storage. It involves moving water between two reservoirs at different elevations to store and generate electricity. When there is excess electricity, water is pumped from the lower reservoir to the upper reservoir. When electricity demand is high, the stored water is released back to the lower reservoir through turbines to generate electricity. This system helps in balancing the grid and storing energy for later use.

Ans: (d) Wastewater treatment technologies.

Membrane bioreactors (MBRs) are advanced wastewater treatment technologies that combine biological treatment processes with membrane filtration. They are used to treat municipal and industrial wastewater by enhancing the efficiency of solids and pathogens removal through filtration. MBRs offer improved water quality and reduced footprint compared to traditional wastewater treatment methods. Therefore, they are specifically discussed in the context of wastewater treatment technologies.