Science and Technology (Part-III)

Total Questions: 28

21. Which one of the following is the context in which the term "qubit" is mentioned ? [2022-1]

Correct Answer: (b) Quantum Computing
Solution:

Option (b) is correct: Just as a bit is the basic unit of information in a classical computer, a qubit is the basic unit of information in a quantum computer.
• Quantum computing is a cutting-edge technology that uses the principles of quantum mechanics to process information in fundamentally different ways than classical computers.
• Unlike classical bits, which represent data as 0 or 1, quantum bits or qubits can exist in multiple states simultaneously due to superposition. This allows quantum computers to perform complex calculations at unprecedented speeds.
• Quantum entanglement, another key principle, enables qubits to be interconnected, allowing for more efficient problem-solving. Quantum computing is especially promising for tasks like cryptography, optimization, drug discovery, and machine learning, where classical computers struggle.
• While still in its early stages, with challenges like error correction and qubit stability, quantum computing has the potential to revolutionize industries and solve problems beyond the reach of classical systems.

22. Consider the following communication technologies: [2022-1]

1. Closed-circuit Television

2. Radio Frequency Identification

3. Wireless Local Area Network

Which of the above are considered Short-Range devices/technologies?

Correct Answer: (d) 1, 2 and 3
Solution:

• Short Range Devices (SRD) are radio devices that offer a low risk of interference with other radio services, usually because of their transmitted power, and hence their range is low.
• The definition ‘Short Range Device’ may be applied to many different types of wireless equipment including various forms of:
• Access control (including door and gate openers).
• Alarms and movement detectors.
• Cordless audio devices, including wireless microphones.
• Closed-circuit television (CCTV): CCTV (closed-circuit television) is a TV system in which signals are not publicly distributed but are monitored, primarily for surveillance and security purposes.
• Wireless Local Area Networks (WLAN): A wireless local area network (WLAN) is a wireless distribution method for two or more devices.
• WLANs use high-frequency radio waves and often include an access point to the Internet.
• A WLAN allows users to move around the coverage area, often a home or small office, while maintaining a network connection.
• A WLAN is sometimes called a local area wireless network (LAWN).
• Radio Frequency Identification (RFID): Radio Frequency Identification (RFID) is a technology that uses radio waves to passively identify a tagged object.
• It is used in several commercial and industrial applications, from tracking items along a supply chain to keeping track of items checked out of a library.

23. In the context of vaccines manufactured to prevent COVID-19 pandemic, consider the following statements: [2022-1]

1. The Serum Institute of India produced COVID-19 vaccine named Covishield using mRNA platform.

2. Sputnik V vaccine is manufactured using vector based platform.

3. COVAXIN is an inactivated pathogen based vaccine.

Which of the statements given above are correct?

Correct Answer: (b) 2 and 3 only
Solution:Statement 1 is wrong: Covishield does not use mRNA it uses viral vector platform. Therefore by elimination the answer is (b).

• Statement 1 is incorrect: The Serum Institute of India produced COVID-19 vaccine named Covishield but not using mRNA platform. It has been prepared using the viral vector platform. In the vaccine, a chimpanzee adenovirus – ChAdOx1 – has been modified to enable it to carry the COVID-19 spike protein into the cells of humans. This cold virus is basically incapable of infecting the receiver, but will teach the immune system to prepare a mechanism against such viruses. The same technology was used to prepare vaccines for viruses like Ebola.
• Statement 2 is correct: Sputnik V, the world’s first registered vaccine, is based on the human adenoviral vector-based platform. The gene from adenovirus, which causes the infection, is removed while a gene with the code of a protein from another virus spike is inserted.
• Statement 3 is correct: Covaxin is an inactivated viral vaccine. It is developed with Whole-Virion Inactivated Vero Cell-derived technology. That is, it contains inactivated viruses that cannot infect a person, but still teach the immune system to prepare a defence mechanism against the active virus.

24. Which one of the following words/phrases is most appropriately used to denote "an interoperable network of 3D virtual worlds that can be accessed simultaneously by millions of users, who can exert property rights over virtual items"? [2024-1]

Correct Answer: (c) Metaverse
Solution:The most appropriate word/phrase to describe the given concept is 'metaverse'. The metaverse is a convergence of physical and virtual spaces accessed via immersive technologies like virtual, augmented, and mixed reality. Seen as the next internet iteration, it is a persistent, shared 3D virtual world where avatars represent users, enabling them to move seamlessly between experiences. In this space, users can carry their identities and monetary assets, making the metaverse a collective digital environment integrating various aspects of daily life into a cohesive virtual experience. Hence the correct answer is (c).

25. Consider the following statements: [2024-1]

Statement-I: Giant stars live much longer than dwarf stars.

Statement-II: Compared to dwarf stars, giant stars have a greater rate of nuclear reactions.

Which one of the following is correct in respect of the above statements ?

Correct Answer: (d) Statement-I is incorrect, but Statement-II is correct
Solution:Statement I is incorrect because giant stars have shorter lifetimes compared to dwarf stars. Their massive cores burn nuclear fuel more rapidly, leading to a quicker depletion of resources and thus a shorter lifespan.

Giant stars, with higher mass, possess hotter, denser cores leading to intense nuclear reactions. This boosts their brightness and energy output significantly compared to stars with lower mass. Thus, Statement II is correct.

26. Consider the following activities: [2024-1]

1. Identification of narcotics on passengers at airports or in aircraft

2. Monitoring of precipitation

3. Tracking the migration of animals

In how many of the above activities can the radars be used?

Correct Answer: (c) All three
Solution:Radars detect and locate objects using radio waves, essential in aviation, maritime navigation, weather forecasting, and military applications. They precisely track distance, speed, and direction over long distances and in various conditions. At airports, radars can identify narcotics on passengers and aircraft.

Weather radars, especially Doppler types, monitor precipitation and predict weather patterns. Additionally, radar technology tracks animal migration, particularly birds and bats, by monitoring their flight patterns and migration routes over large distances. Thus in all three activities radars can be used.

27. Which one of the following is the exhaust pipe emission from Fuel Cell Electric Vehicles, powered by hydrogen? [2024-1]

Correct Answer: (d) Water vapour
Solution:The exhaust air from Fuel Cell Electric Vehicles (FCEVs) powered by hydrogen consists of pure water vapor. FCEVs emit only water vapor, making them locally emission-free and contributing to cleaner air in cities. Hence, the correct answer is (d).
What is a Fuel Cell
• It is an electrochemical device that converts chemical energy into electrical energy by combining a fuel (usually hydrogen) with an oxidant (typically oxygen from the air).
• Unlike conventional batteries, which store energy, fuel cells produce electricity as long as fuel is supplied. The core reaction involves hydrogen molecules splitting into protons and electrons at the anode, with electrons creating an electric current through an external circuit.
• The protons move through the electrolyte to the cathode, where they combine with oxygen to form water and heat as byproducts. This process is clean, with water being the primary waste, making fuel cells an environmentally friendly alternative to fossil fuels.
• Fuel cells are used in a variety of applications, from powering electric vehicles (like hydrogen-powered cars) to providing electricity in remote locations. They offer advantages like high efficiency, low emissions, and the potential for renewable energy integration.

28. Recently, the term "pumped-storage hydropower" is actually and appropriately discussed in the context of which one of the following? [2024-1]

Correct Answer: (c) Long duration energy storage
Solution:The term "pumped-storage hydropower" pertains to long-term energy storage. This involves a hydroelectric storage system using two water reservoirs situated at different heights.

Power is generated when water flows from the higher reservoir to the lower one through a turbine (discharge).

To restore the system, energy is needed to pump the water back up to the upper reservoir (recharge). Hence, the correct answer is (c).