Information and Communication Technology: UPSC Previous Year Questions (Science and Technology)

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

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.