With reference to the Indian economy, “Collateral Borrowing and Lending Obligations” are the instruments of :
UPSC IAS
32. “Membrane Bioreactors” are often discussed in the context of which one
“Membrane Bioreactors” are often discussed in the context of which one of the following ?
33. Recently, the term “pumped-storage hydropower” is actually and appropr
Recently, the term “pumped-storage hydropower” is actually and appropriately discussed in the context of which one of the following ?
34. Which one of the following is the exhaust pipe emission from Fuel Cell
Which one of the following is the exhaust pipe emission from Fuel Cell Electric Vehicles, powered by hydrogen ?
35. In which of the following are hydrogels used ? Select the correct answ
In which of the following are hydrogels used ?
Select the correct answer using the code given below :
- Controlled drug delivery in patients
- Mobile air-conditioning systems
- Preparation of industrial lubricants
1. Controlled drug delivery in patients: Hydrogels are extensively used in drug delivery systems. Drugs can be incorporated into the hydrogel matrix and released in a controlled manner as the hydrogel swells or degrades, allowing for sustained or targeted drug release. This is a well-established application.
2. Mobile air-conditioning systems: Hydrogels can be used in certain types of cooling systems, particularly those involving moisture absorption and evaporation. For instance, they can be incorporated into evaporative cooling pads or desiccant systems for moisture removal, which is a component in some air conditioning or cooling technologies, including potentially mobile or portable systems exploring energy efficiency or alternative cooling methods. While not in traditional compressor-based ACs, they are used in specific advanced or niche cooling applications.
3. Preparation of industrial lubricants: Certain hydrogels exhibit excellent lubricating properties, especially in aqueous environments. They can reduce friction between surfaces and are explored or used as lubricants in various industrial applications, particularly in machinery and biomedical devices where traditional oil-based lubricants are unsuitable. This is an established application.
Based on the known uses of hydrogels, all three activities are valid applications.
36. Consider the following aircraft : Rafael MiG-29 Tejas MK-1 How ma
Consider the following aircraft :
- Rafael
- MiG-29
- Tejas MK-1
How many of the above are considered fifth generation fighter aircraft ?
Let’s examine the listed aircraft:
– Rafael: The Dassault Rafale is a French twin-engine, canard delta wing, multirole fighter aircraft. It is widely considered a 4.5 generation fighter, incorporating advanced technologies and capabilities that bridge the gap between 4th and 5th generation aircraft, but it lacks the full-spectrum stealth required for true 5th generation status.
– MiG-29: The Mikoyan MiG-29 is a Soviet/Russian twin-engine jet fighter aircraft developed in the 1970s. It is widely considered a 4th generation fighter.
– Tejas MK-1: The HAL Tejas is an Indian single-engine, delta wing, light multirole fighter. The Tejas MK-1 is considered a 4th generation fighter aircraft. Subsequent planned variants (like Tejas MK-2 or the AMCA) are expected to incorporate more advanced features.
None of the aircraft listed (Rafael, MiG-29, Tejas MK-1) are classified as true fifth-generation fighter aircraft. Examples of fifth-generation fighters include the Lockheed Martin F-22 Raptor, Lockheed Martin F-35 Lightning II, Sukhoi Su-57, Chengdu J-20, and Shenyang FC-31/J-31.
Therefore, none of the aircraft listed are fifth-generation fighter aircraft.
37. Consider the following activities : Identification of narcotics on p
Consider the following activities :
- Identification of narcotics on passengers at airports or in aircraft
- Monitoring of precipitation
- Tracking the migration of animals
In how many of the above activities can the radars be used ?
1. Identification of narcotics on passengers at airports or in aircraft: Advanced radar-based scanners, particularly millimeter-wave scanners, are used in airport security for screening passengers. These scanners can detect concealed objects, including weapons and potentially other items like large quantities of narcotics, underneath clothing. So, radar can be used in this activity.
2. Monitoring of precipitation: Weather radar is a fundamental tool in meteorology used to detect, locate, and track precipitation (rain, snow, hail). It estimates the intensity and type of precipitation and predicts its movement. So, radar is used in this activity.
3. Tracking the migration of animals: Radar is widely used in biological research, particularly in ornithology and entomology, to study the migration patterns of birds and insects. Weather radar systems often detect large flocks of birds or insect swarms, and specialized biological radars are also used for more detailed tracking. So, radar can be used in this activity.
Since radar can be used in all three listed activities, the correct answer is “All three”.
38. Which one of the following is synthesised in human body that dilates b
Which one of the following is synthesised in human body that dilates blood vessels and increases blood flow ?
Nitric oxide (NO) is a molecule produced by cells in the endothelium (lining of blood vessels) and other tissues. It is a potent vasodilator, meaning it causes the smooth muscles in the walls of blood vessels to relax, leading to increased diameter and blood flow. This process is crucial for regulating blood pressure and blood flow to different parts of the body.
Nitrous oxide (N₂O), also known as laughing gas, is an anesthetic and analgesic gas used in medicine but is not synthesized in the human body for vasodilation.
Nitrogen dioxide (NO₂) and Nitrogen pentoxide (N₂O₅) are oxides of nitrogen that are primarily environmental pollutants and industrial chemicals, not molecules synthesized endogenously in the human body for physiological functions like vasodilation.
Therefore, Nitric oxide is the correct answer.
39. Consider the following statements : Statement-I : Giant stars live muc
Consider the following statements :
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 ?
Statement-I: “Giant stars live much longer than dwarf stars.” This statement is incorrect. Giant stars, being more massive than dwarf stars (like our Sun, a G-type dwarf), have much stronger gravitational forces. This results in higher temperatures and pressures in their cores, which accelerates the rate of nuclear fusion. Although they have more fuel, they burn it at a vastly higher rate, leading to significantly shorter lifespans compared to dwarf stars. Dwarf stars, with their slower rate of fusion, can live for billions or even trillions of years.
Statement-II: “Compared to dwarf stars, giant stars have a greater rate of nuclear reactions.” This statement is correct. As explained above, the higher core temperatures and pressures in giant stars lead to a much higher rate of nuclear fusion reactions (converting hydrogen to helium) compared to dwarf stars. This high reaction rate is responsible for their high luminosity.
Statement I is incorrect, and Statement II is correct. Statement II actually explains *why* Statement I is incorrect (higher reaction rate leads to shorter lifespan). Therefore, Option D is the correct choice.
40. With reference to radioisotope thermoelectric generators (RTGs), consi
With reference to radioisotope thermoelectric generators (RTGs), consider the following statements :
- RTGs are miniature fission reactors.
- RTGs are used for powering the onboard systems of spacecrafts.
- RTGs can use Plutonium-238, which is a by-product of weapons development.
Which of the statements given above are correct ?
Statement 1: “RTGs are miniature fission reactors.” This statement is incorrect. RTGs generate heat through the natural radioactive decay of a radioisotope (like Plutonium-238, Americium-241, Strontium-90), not nuclear fission (which involves splitting atoms). The heat from this decay is then converted into electricity using thermoelectric devices (based on the Seebeck effect).
Statement 2: “RTGs are used for powering the onboard systems of spacecrafts.” This statement is correct. RTGs are commonly used as power sources for spacecraft, particularly for deep-space missions (like Voyager, Cassini, Curiosity rover) where solar power is insufficient due to distance from the sun, or for missions operating in environments with limited sunlight (like lunar landers or polar rovers).
Statement 3: “RTGs can use Plutonium-238, which is a by-product of weapons development.” This statement is correct. Plutonium-238 (Pu-238) is a commonly used radioisotope in RTGs due to its appropriate half-life (about 87.7 years) and high energy density. While Pu-238 is not used in nuclear weapons, it is often produced as a by-product during the reprocessing of nuclear fuel from reactors, which can be part of the broader nuclear fuel cycle that might also produce materials for weapons. Specifically, Pu-238 is produced by irradiating neptunium-237. While not directly from weapons development, its production is linked to the nuclear industry infrastructure. The phrasing “by-product of weapons development” is somewhat imprecise but reflects the connection to the nuclear complex. Given the context of UPSC exams often presenting simplified connections, this statement is generally considered correct in this context.
Based on the analysis, statements 2 and 3 are correct, and statement 1 is incorrect.