UPSC 2019 Prelims Questions with Answers

Explanation

Buddhism has several sects, with the main ones being Theravada, which follows the earliest teachings of the Buddha, and Mahayana, which emphasizes the Bodhisattva path and compassion for all beings. Additionally, Vajrayana (or Tibetan Buddhism) incorporates esoteric practices and is a significant branch of Mahayana. All three statements are features of Mahayana Buddhism. The Mahayana sect of Buddhism emerged during the Fourth Buddhist Council held in Kashmir during the reign of Kanishka. The deification of Buddha and worship of images of Buddha and Bodhisattvas was a distinctive feature of this sect. A Bodhisattvas is someone who has compassion within himself or herself and who can make another person smile or help someone suffer less.

Explanation

Statement 1 is incorrect: LTE is a 4G (Fourth Generation) wireless communication standard, not 3G. It offers higher data transfer speeds compared to 3G technologies. VoLTE is a service that allows voice calls to be transmitted over the LTE network thereby providing high-quality voice services. Both LTE and VoLTE are associated with 4G technology, not 3G.

Statement 2 is incorrect: LTE is not a data-only technology as it supports both data and voice services. However without VoLTE, voice calls on LTE networks typically fall back to 3G or 2G networks (a process called Circuit-Switched Fallback, or CSFB). VoLTE is not voice-only as it enhances voice call quality and efficiency while still supporting data services.

Explanation

Statement 1 is incorrect: AR overlays digital elements onto the real world, enhancing the user’s perception without replacing the physical environment. Examples include Pokémon Go and AR navigation apps.

Statement 2 is incorrect: VR creates an immersive digital environment that replaces the real world entirely, isolating the user through devices like VR headsets. Examples include virtual classrooms and gaming environments.

Statement 3 is correct: Augmented Reality enhances the user’s experience by integrating digital elements with their physical environment in real-time. AR applications utilize cameras on smartphones, tablets, or PCs to superimpose virtual features, such as graphics or text, over the real-world view displayed on the device’s screen.

Statement 4 is correct: Virtual Reality isolates the user from their physical surroundings by immersing them in a fully simulated digital environment. VR systems achieve this through specialized devices, such as VR headsets, which block out external visual and auditory input. This technology is commonly used for gaming, training simulations, and immersive experiences, offering users a sense of presence within the virtual world.

Explanation

A digital signature is a type of electronic signature that can be used to verify the identity of the person sending a message or signing a document and to guarantee that the message’s or document’s original content hasn’t changed. Digital signatures are portable and impossible for anyone to forge.

Statement 1 is incorrect: A digital signature is a cryptographic technique used to validate the authenticity and integrity of digital messages or documents. It is not primarily used to identify the certifying authority. A digital certificate serves that purpose by linking a public key with the identity of the certificate authority that issued it.

Statement 2 is incorrect: While digital signatures can authenticate the origin of a message or document, their primary function is to ensure that the content has not been altered and to verify the sender’s identity in the context of that specific document. They are not typically used as general proof of identity for accessing information or servers; other mechanisms, such as passwords or digital certificates, serve that purpose

Statement 3 is correct: Digital signatures use cryptographic methods to provide authentication of original and unmodified documentation, ensuring that the content has not been altered since it was signed

Explanation

Statement 1 is correct: The coal sector in India was nationalized in two phases under Prime Minister Indira Gandhi. The first phase took place in 1971 with the nationalization of coking coal mines, and the second phase occurred in 1973 with the nationalization of non-coking coal mines. This was done to ensure proper development of the coal sector and to prevent exploitation by private players.

Statement 2 is incorrect: Coal blocks are not allocated on a lottery basis. The allocation of coal blocks in India is done through a transparent and competitive bidding process as per the Coal Mines (Special Provisions) Act, 2015. This process ensures fairness and efficiency in the allocation of coal re-sources.

Statement 3 is incorrect: India still imports coal to meet its domestic demand, particularly high-grade coal that is not sufficiently available domestically. Despite having large coal reserves, India faces challenges in coal production, transportation, and quality, which necessitate imports. India is not self-sufficient in coal products.

Explanation

Electronic devices can be comfortably worn on the body are known as wearables. Real-time information tracking is done with these wearable gadgets. They have motion sensors that capture an image of user’s daily activity and sync it with laptops or mobile devices.

Statement 1 is correct: Wearable devices like smartwatches and fitness trackers equipped with GPS can track a person’s real-time location which makes them useful for navigation, fitness activities, and safety purposes, especially for outdoor enthusiasts and travelers.

Statement 2 is correct: Wearables can monitor sleep by analyzing heart rate, movement, and breathing patterns. Devices like the Oura Ring provide detailed insights into sleep quality, helping users identify issues and improve their overall sleep health.

Statement 3 is correct: Certain wearables such as modern hearing aids and Apple’s AirPods Pro assists people with hearing impairments by amplifying sounds and reducing background noise, offering an affordable and efficient solution for mild-to-moderate hearing loss.

Explanation

For assessing chlorophyll content from remote sensing data utilising a multispectral imaging system, the Normalized Area Vegetation Index (NAVI) has been developed. The most widely used instruments are radiometers and photometers, which can collect radiation that is emitted and reflected at a variety of frequencies. Additionally, they can be used to identify the emission spectra of different substances, providing information on atmospheric chemical concentrations.

Statement 1 is correct: Satellite remote sensing such as hyperspectral imaging can estimate chlorophyll levels in vegetation by analyzing specific spectral wavelengths. This technique is widely used to evaluate plant health and productivity over large regions without requiring direct sampling.

Statement 2 is correct: Advanced remote sensing tools, including drones with multispectral sensors, help monitor methane emissions from rice paddies. By integrating environmental data with computational models, these methods provide a non-invasive way to assess emissions across agricultural landscapes.

Statement 3 is correct: Remote sensing satellites measure land surface temperatures by detecting thermal infrared radiation emitted from the Earth’s surface. This data is critical for applications like climate research, urban heat management, and agricultural monitoring, offering accurate temperature readings across various regions.

Explanation

Waste-to-Energy (WTE) technologies consist of any waste treatment process that creates energy in the form of electricity or heat from several types of waste: from the semi-sol-id (e.g. thickened sludge from effluent treatment plants) to liquid (e.g. domestic sewage) waste. Landfill gas recovery, Gasification, Pyrolisis, Thermal Depolymerisation are examples of Waste-to-Energy (WTE) technologies.

Option (d) is correct: Pyrolysis is a process of chemical de-composition of organic matter brought about by heat. In this process, the organic material is heated in the absence of air until the molecules thermally break down to become a gas comprising smaller molecules (known collectively as syngas). Gasification can also take place as a result of partial combustion of organic matter in the presence of a restricted quantity of oxygen or air. The gas, so produced, is known as producer gas. The gases produced by pyrolysis mainly comprise carbon monoxide (25%), hydrogen and hydrocarbons (15%), and carbon dioxide and nitrogen (60%). It is used commercially as a waste to energy system that converts municipal solid waste into synthesis gas (syngas) containing hydrogen and carbon monoxide that can be used to generate power.

Explanation

Microbeads are manufactured solid plastic particles of less than one millimetre in their largest dimension. They are most frequently made of polyethene but can be of other petrochemical plastics such as polypropylene and polystyrene. They are used in exfoliating personal care products, toothpaste and in biomedical and health-science research.

Option (a) is correct: Microbeads can cause plastic particle water pollution and pose an environmental hazard for aquatic animals in freshwater and ocean water. NGT had earlier directed the GoI to test cosmetic products containing microbeads after a plea sought a ban on their use on the ground they are extremely dangerous for aquatic life and the environment.

Explanation

Methane hydrate is an ice-like substance formed when CH4 and water combine at low temperature (up to 250C) and moderate pressure (greater than 3-5 MPa, which corresponds to combined water and sediment depths of 300 to 500 m).

Statement 1 is correct: Owing to the melting of ice, global warming might trigger the release of methane gas from these deposits hence having a significant impact on climate change.

Statement 2 is correct: Sediment and sedimentary rock units below Arctic permafrost have the temperature and pressure conditions suitable for the formation and stability of methane hydrate.

Statement 3 is correct: Methane is relatively short-lived in the atmosphere; a molecule of methane is oxidised to water and carbon dioxide within a decade or so, mainly by reaction with other trace gases.