UPSC Prelims 2024 Analysis

Explanation

Fifth-generation fighter aircraft are characterized by advanced stealth, superior agility, advanced avionics, and integrated computer systems. Let's consider the aircraft listed:

1. Rafael (Rafale): This is a 4.5 generation multirole fighter aircraft developed by Dassault Aviation.

2. MiG-29: This is a fourth-generation multirole fighter aircraft developed by Mikoyan in the Soviet Union.

3. Tejas MK-1: This is a fourth-generation light multirole fighter aircraft developed by Hindustan Aeronautics Limited (HAL) in India.

 None of the above aircraft are considered fifth-generation fighter aircraft.

Explanation

Nitric oxide (NO) is synthesized in the human body by the enzyme nitric oxide synthase from the amino acid arginine. It plays a crucial role in dilating blood vessels, which increases blood flow and reduces blood pressure. This function helps in regulating cardiovascular health.

Why the other options are incorrect:

B. Nitrous oxide: Used as an anesthetic, not a vasodilator.

C. Nitrogen dioxide: A toxic air pollutant, not involved in vasodilation.

D. Nitrogen pentoxide: A reactive compound, not related to blood vessel dilation.

Explanation

All three plants—Groundnut, Horse-gram, and Soybean—belong to the pea family, scientifically known as Leguminosae or Fabaceae. This family is characterized by plants that produce legumes (pods containing seeds). Here's a breakdown of each:

• Groundnut (Arachis hypogaea):

  • Groundnut, also known as peanut, belongs to the Leguminosae family. It produces peanuts, which grow underground in pods, typical of legumes.

  • It is part of the subfamily Faboideae, a major division within the pea family.

• Horse-gram (Macrotyloma uniflorum):

  • Horse-gram is another plant in the Leguminosae family. It is commonly cultivated in tropical regions and is known for its high protein content and use in animal feed and food.

  • It belongs to the subfamily Faboideae as well.

• Soybean (Glycine max):

  • Soybean, one of the most important leguminous crops, also belongs to the Leguminosae family. It is widely grown for its edible beans and oil extraction.

  • Soybean is part of the subfamily Faboideae too.

All three plants are legumes, characterized by their pod-like fruit and ability to fix nitrogen from the atmosphere through a symbiotic relationship with bacteria in their root nodules.

Explanation

Explanation:

• Statement 1: Incorrect. RTGs (Radioisotope Thermoelectric Generators) are not miniature fission reactors. Fission reactors use nuclear fission, a process of splitting atoms to release a tremendous amount of energy. RTGs, on the other hand, utilize the natural radioactive decay of isotopes to generate heat, which is then converted to electricity through a process called thermoelectricity.

• Statement 2: Correct. RTGs are indeed a reliable power source for spacecraft, especially those venturing far from the sun where solar panels become ineffective. They provide consistent, low-level electric power for extended periods, making them ideal for probes, satellites, and rovers in deep space.

• Statement 3: Correct. Plutonium-238 is a common isotope used in RTGs due to its long half-life (the time it takes for half of the material to decay) and its ability to generate a steady heat output from its decay process. While it can be a byproduct of weapons development, there are also alternative ways to produce Plutonium-238 specifically for peaceful applications like RTGs.

Explanation

Explanation:

Distributed Energy Resources (DERs) are small-scale units of power generation or storage that are situated closer to the end-users. Let's analyze each option:

• Battery storage: These store energy and can be deployed within the distribution network or at the consumer end, making them DERs.

• Biomass generators: These can be small-scale and located near the biomass source, making them suitable for distributed generation.

• Fuel cells: Similar to biomass generators, fuel cells can be deployed in a decentralized manner, qualifying as DERs.

• Rooftop solar photovoltaic units: These are a classic example of DERs, generating power at the point of consumption.

Therefore, all four options are considered Distributed Energy Resources.

Explanation

Explanation:

Radars can be used in the following activities:

• Identification of narcotics on passengers at airports or in aircraft: This is typically done using X-ray scanners or advanced imaging technologies like millimeter wave scanners, not traditional radar.

• Monitoring of precipitation: Radars, specifically weather radars, are commonly used to monitor precipitation. They can detect rain, snow, and other weather conditions by bouncing radio waves off precipitation particles.

• Tracking the migration of animals: Radars can be used to track the migration of birds and other animals. They are often used in ornithological studies to monitor bird migration patterns.

Explanation

Pumped-storage hydropower (PSH) is used for long-duration energy storage. It works by pumping water to a higher reservoir during low electricity demand and releasing it to generate power during peak demand. This process helps balance the grid supply and demand, making PSH an effective tool for energy storage over extended periods.

Thus, the correct answer is C.

Explanation

Explanation:

Hydrogels are used in the following applications:

• Controlled drug delivery in patients: Hydrogels are commonly used in biomedical applications, including controlled drug delivery systems, due to their ability to absorb and release drugs in a controlled manner.

• Mobile air-conditioning systems: Hydrogels can be used in evaporative cooling systems, including mobile air-conditioning systems, where they help in the absorption and release of water to enhance cooling.

• Preparation of industrial lubricants: Hydrogels are not typically used in the preparation of industrial lubricants. Lubricants generally require materials with specific viscosity and stability properties that hydrogels do not provide.

Explanation

Explanation:

Metaverse: This term accurately describes a network of interconnected, persistent 3D virtual spaces. 

Key characteristics of the metaverse often include:

• Interoperability: Users can move between different virtual worlds seamlessly.

• User-Generated Content: Users can create, own, and trade virtual assets.

• Social Interaction: The metaverse facilitates social experiences and interactions.

Let's look at why the other options are incorrect:

• Big data analytics: This involves analyzing large and complex datasets to uncover patterns and insights. It's not directly related to virtual worlds.

• Cryptography: This focuses on secure communication and data protection techniques. While relevant to security within a metaverse, it doesn't define the concept itself.

• Virtual matrix: This term is not commonly used to describe the concept outlined in the question. The term 'matrix' is often associated with a grid-like structure or a virtual reality environment, but not the broader interconnected network the question describes.

Explanation

Explanation:

• Statement-I: Giant stars do not live much longer than dwarf stars. In fact, giant stars have shorter lifespans compared to dwarf stars because they burn through their nuclear fuel at a much faster rate.

• Statement-II: Compared to dwarf stars, giant stars have a greater rate of nuclear reactions. This is correct as giant stars are more massive and have higher pressures and temperatures in their cores, leading to faster nuclear fusion rates.

Explanation

Fuel Cell Electric Vehicles (FCEVs) powered by hydrogen generate electricity by combining hydrogen (H₂) with oxygen (O₂) in a fuel cell. This process produces electricity, heat, and the only exhaust emission is water vapour (H₂O), making hydrogen fuel cells zero-emission.