Science and Technology: UPSC Previous Year Questions (Prelims)

Explanation

According to the Food Safety and Standards (Packaging and Labeling) Regulations, 2011, pre-packaged items in India must display key information, including:

Nutrition information List of ingredients (including additives) Vegetarian/Non-vegetarian label Date of manufacture and packing Best-before date Lot number, Code number, or Batch number The regulations mandate that foods containing allergens such as cereals containing gluten, nuts, soybeans, milk, and fish must declare the presence of these allergens on the label. However, the regulations do not require a specific medical recommendation regarding allergic reactions

Explanation

Viruses can infect bacteria and are commonly known as bacteriophages. They attach to bacterial cells and inject their genetic material, leading to the production of new viral particles within the bacterial host. Viruses that infect fungi are termed mycoviruses. These viruses can influence the physiology and pathogenicity of their fungal hosts. Notably, studies have shown that fungi can acquire viruses and viroids from plants, indicating cross-kingdom transmission. Numerous viruses infect plants, causing a variety of diseases that can significantly impact agricultural productivity. These plant viruses can be transmitted through various means, including insect vectors, mechanical damage, and seed transmission. Ex-Tobacco Mosaic Virus (TMV), infect plants, causing diseases that affect crop yields and quality.

Explanation

Statement 1 is correct: LiFi (Light Fidelity) uses visible light, ultraviolet, or infrared light to transmit data. This technology works through light-emitting diodes (LEDs), which modulate light signals at extremely high speeds to carry information. Unlike traditional radio frequency-based wireless systems, LiFi leverages the light spectrum for communication.

Statement 2 is correct: LiFi is a wireless communication technology that does not require cables for data transmission. In laboratory conditions, it has demonstrated speeds significantly faster than WiFi, reaching up to 224 Gbps. However, its performance depends on line-of-sight and is more suitable for indoor environments.

Explanation

AstroSat is the first dedicated Indian astronomy mission aimed to study celestial sources in X-ray, optical and UV spectral bands. The payloads cover the energy bands of Ultraviolet (Near and Far), limited optical and X-ray regime (0.3 keV to 100keV). The ability to simultaneously observe multiple celestial objects at multiple wavelengths with a single satellite is one of the special aspects of the AstroSat project.

Statement 1 is incorrect: India has joined the exclusive club of nations with its own space observatory with the successful launch of ASTROSAT, joining the US, Japan, Russia, and Europe. ASTROSAT, India’s first dedicated multi-wavelength space observatory, will aid in the knowledge of the cosmos.

Statement 2 is incorrect: AstroSat with a lift-off mass of 1515 kg was launched into a 650 km orbit inclined at an angle of 6 deg to the equator by PSLV-C30 from Satish Dhawan Space Centre, Sriharikota.

Explanation

Mangalyaan/Mars Orbiter Mission (MOM), the maiden interplanetary mission of ISRO, was launched on PSLV-C25. It entered into Martian orbit in its first attempt. MOM had completed 1000 Earth days in its orbit well beyond its designed mission life of six months.

Statement 1 and 3 are correct: The Mangalyaan launched by ISRO is also called the Mars Orbiter Mission. With this India became the first Asian nation to reach Mars orbit, and the first nation in the world to do so in its first attempt.

Statement 2 is incorrect: It is India’s first interplanetary mission and ISRO has become the fourth space agency to reach Mars, after the Soviet space Programme, NASA and the EuropeanSpace Agency.

Explanation

The International Thermonuclear Experimental Reactor (ITER) is a collaborative international project involving countries such as India, China, the European Union, Japan, Korea, Russia, and the United States. Its primary goal is to demonstrate the feasibility of nuclear fusion as a sustainable and large-scale energy source by replicating the fusion processes that power the sun. If ITER succeeds then the immediate advantage for India would be the capability to construct fusion reactors for power generation. Fusion energy offers a carbon-free and environmentally sustainable alternative, with the potential to provide a significant amount of power compared to fossil fuels.

Explanation

Option (d) is correct: H1N1 is a subtype of the Influenza A virus which causes respiratory infections in humans and animals. It is commonly known as Swine Flu because it was originally found in pigs. The virus is a result of genetic reassortment between human, swine, and avian influenza viruses.

Option (a),(b) and (c) are incorrect:

AIDS (Acquired Immunodeficiency Syndrome) is caused by the HIV (Human Immunodeficiency Virus) and not the H1N1 virus. HIV primarily affects the immune system (CD4+ T cells) which leads to weakened immunity. Bird Flu (Avian Influenza) is caused by a different subtype of Influenza A virus, such as H5N1, H7N9, H5N8, etc. H1N1 is not responsible for Bird Flu. Dengue is a mosquito-borne viral disease caused by the Dengue virus (DENV), which is transmitted by the Aedes aegypti mosquito. Dengue symptoms include high fever, severe headache, pain behind the eyes, joint pain and rash.

Explanation

Near Field Communication (NFC) is a short-range wireless technology that allows devices to communicate by tapping or bringing them close together. NFC is used in various applications, including contactless payments, data exchange, and access control.

Statement 1 is correct: NFC is a short-range wireless communication technology that enables devices to exchange data over distances typically up to 4 centimeters. It operates by generating electromagnetic fields through inductive coupling at a frequency of 13.56 MHz, which facilitates the transfer of information between devices. This contactless technology is widely used in mobile payments, access control, and data exchange.

Statement 2 is incorrect: NFC technology is designed for an operation distance of a few centimeters(not meter). This makes it more difficult for attackers to record the communication between an NFC Forum Device and an NFC Forum Tag compared to other wireless technologies which have a working distance of several meters.

Statement 3 is correct: NFC technology incorporates encryption methods to secure data transmission, ensuring that sensitive information remains protected during exchange. Techniques such as AES (Advanced Encryption Standard) are commonly employed to maintain confidentiality and integrity.

Explanation

: Nanotechnology is a field of science and engineering that deals with the manipulation of matter on an atomic and molecular scale, typically between 1 to 100 nanometers. It involves the design, synthesis, characterization, and application of materials, devices, and systems at this incredibly small scale. This emerging field has the potential to revolutionize various sectors, including medicine, electronics, materials science, and energy, by creating new materials with unique properties and developing innovative technologies with unprecedented capabilities.

Statement 1 is correct: Targeted drug distribution by nanoscale drug carriers is one of the fundamental tenets of nanomedicine. Numerous nanoscale drug delivery technologies, such as liposomes, dendrimers, quantum dots, nanotubes, polymeric biodegradable nanoparticles, and nanocapsules, have been studied.

Statement 2 is correct: Nanotechnology plays a significant role in gene therapy by creating nanocarriers that can deliver genetic material, such as DNA or RNA, to specific cells. These nanocarriers protect genetic material from degradation and improve its delivery into target cells, offering potential treatments for genetic disorders.

Explanation

The IceCube Neutrino Observatory is the first of its kind, designed to explore the cosmos from deep within the ice at the South Pole. It is operated by the IceCube Collaboration, an international team of scientists conducting research in this field. By detecting high-energy cosmic neutrinos, IceCube enables the study of some of the universe’s most violent astrophysical events, including stellar explosions, gamma-ray bursts, and catastrophic interactions involving black holes and neutron stars.

Statement 1 is correct: The IceCube Neutrino Observatory is the largest neutrino detector globally, occupying a cubic kilometer of ice at the South Pole. It detects high-energy neutrinos from cosmic sources like supernovae, black holes, and gamma-ray bursts.

Statement 2 is correct: IceCube plays a critical role in the search for dark matter by detecting neutrinos produced when dark matter particles, such as WIMPs (Weakly Interacting Massive Particles), interact or annihilate. This makes it a vital tool in astrophysical and particle physics research.

Statement 3 is correct: IceCube’s detectors are buried at depths between 1,450 meters and 2,450 meters in Antarctic ice. This depth reduces interference from cosmic rays and other particles, allowing it to detect faint light signals from neutrino interactions.