UPSC Essentials | Daily subject-wise quiz : Science and Technology MCQs on Van Allen Probes, reverse osmosis technology and more (Week 153)

2. The mission eventually concluded after both spacecraft ran out of fuel and could no longer orient themselves toward the Sun.

3. These spacecrafts were launched by the European Space Agency.

Which of the statements given above is/are correct?

(a) 2 only

(b) 1 and 2 only

(c) 2 and 3 only

(d) 1, 2 and 3

Relevance: Space missions and scientific probes are important topics in science and technology for the UPSC Civil Services Examination Prelims. Studying missions like the Van Allen Probes helps in understanding Earth’s radiation belts and space weather phenomena.

Explanation:

— Since the space race started back in 1955, humans have launched thousands of artificial satellites into orbit. Now, a big satellite sent by NASA 14 years ago is coming back to our planet. The spacecraft in question – named Van Allen Probe A- was launched back in August of 2012 alongside its twin- the Van Allen Probe B to study the radiation belts around our planet. Hence, statement 3 is not correct.

— Van Allen Probe A and Van Allen Probe B, originally launched for a two-year mission, ended up collecting extensive data on Earth’s two permanent radiation belts for nearly seven years. The mission eventually concluded after both spacecraft ran out of fuel and could no longer orient themselves toward the Sun. Hence, statement 2 is correct.

— Named after scientist James Van Allen, the spacecraft were designed to fly through and study rings of high-energy radiation particles trapped by Earth’s magnetic field. Hence, statement 1 is correct.

— These doughnut-shaped regions, known as the Van Allen belts, help shield our planet from solar storms, cosmic radiation and streams of charged particles from the Sun, commonly referred to as the solar wind.

Therefore, option (b) is the correct answer.

QUESTION 2

The Reverse osmosis (RO) technology is used in:

1. Water reuse (pharma /biotech)

2. Desalination of brackish water

3. Radioactive waste treatment

Select the correct answer using the codes given below:

(a) 2 only

(b) 3 only

(c) 2 and 3 only

(d) 1, 2 and 3

Relevance: Water purification and treatment technologies like Reverse Osmosis are important under environment, science, and infrastructure in the UPSC Civil Services Examination Prelims. RO technology is widely used in desalination plants and industrial water recycling, which are increasingly relevant for water-stressed regions.

Explanation:

— Saline water contains significant concentrations of dissolved salts (ranging up to 35,000 ppm) and is otherwise unfit for human consumption. Given the scarcity of freshwater sources and a growing population, the need for additional water supplies has long been recognised.

— The use of desalination has been mooted in the US as a means to use a wider variety of water sources. A 2017 US Geological Survey report estimated that the aquifers, which can meet 30% of the country’s water supply needs, could be desalinated for human consumption. It could satisfy nearly 800 years of use at current rates.

— Desalination plants are highly energy-intensive and run on electricity generated from liquid fuels or natural gas, generating 500 to 850 million tons of carbon dioxide emissions annually. Another concern is that reverse osmosis, the predominant desalination method, generates large quantities of saltwater brine, which are typically discharged into the ocean. These can harm marine habitats and kill sea creatures such as plankton and fish larvae.

— Reverse Osmosis can be applied for desalination of brackish water, water reuse (in pharma /biotech, waste water, electrocoating, food and beverage industries) and radioactive waste treatment.

Therefore, option (d) is the correct answer.

QUESTION 3

The main constituents of the Liquefied petroleum gas (LPG) are:

1. Butane

2. Methane

3. Propane

4. Ethane

Select the correct answer using the codes given below:

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 3 and 4 only

Relevance: Energy resources and petroleum products are important topics in UPSC Civil Services Examination Prelims, especially under economy and environment. Questions on the composition and uses of fuels such as LPG, CNG, and natural gas can be asked to test basic conceptual clarity.

Note: In this question, propane (main constitutent of LPG has been added, earlier it was missing out. The question has been updated.

Explanation:

— As the conflict in West Asia pushes up energy and commodity prices, its ripple effects are beginning to spread far beyond oil and gas, with sectors such as textiles, mining and steelmaking in India starting to feel the pressure.

About LPG

— Because of its high octane rating, liquefied petroleum gas (LPG) is commonly utilised in spark-ignition engines.

— The main components of LPG are butane and propane, while ethane is used in smalled quantities. However, the composition of LPG varies greatly between countries and geographical locations due to climatic conditions, physicochemical qualities of crude oil, refining processes, and other factors. Propane is the most readily available hydrocarbon molecule for manufacturing LPG in nations such as the United Kingdom. Similarly, butane is commonly utilised for LPG manufacture in countries with warmer climates.

Therefore, option (c) is the correct answer.

QUESTION 4

The term ‘helioseismology ‘ is defined as:

(a) A method used to determine the distance between the Earth and the Sun.

(b) The study of the magnetic field surrounding the Sun.

(c) The observation of the Sun’s outer atmosphere and solar winds.

(d) A method to detect the movements inside the Sun.

Relevance: Basic concepts related to solar science and space research are part of the science and technology syllabus of the UPSC Civil Services Examination Prelims. Terms like helioseismology help in understanding the internal structure and activity of the Sun, which influence phenomena such as solar cycles and space weather.

Explanation:

— Scientists have possibly detected new evidence of subtle movements of magnetism deep inside the Sun, which may help them better predict solar storms and space weather.

— Scientists used a method called helioseismology to detect the movements inside the Sun. This method is used to study the solar surface to understand the movements inside the Sun, the same way earthquakes are used to study the movements inside the Earth.

— They analysed more than a decade of solar observations collected by the Solar Dynamics Observatory, a satellite operated by NASA. In particular, they used measurements from the satellite’s Helioseismic and Magnetic Imager (HMI)– an instrument designed to track oscillations and magnetic activity across the Sun’s surface.

Therefore, option (d) is the correct answer.

QUESTION 5

Consider the following statements:

1. Both ships and aircraft depend on global navigation satellite systems (GNSS) for position, navigation, and timing (PNT) information.

2. GPS jamming involves the use of a device called a jammer to overpower weaker signals with ‘noise’ on the same frequency.

3. GPS Spoofing provides the pilot (or captain) with false information about their actual location.

How many of the statements given above are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

Relevance: Satellite navigation systems and their vulnerabilities are important topics in science and technology for the UPSC Civil Services Examination Prelims. Concepts like Global Navigation Satellite System, jamming, and spoofing are relevant for understanding modern navigation and cybersecurity threats.

Explanation:

— Both ships and aircraft depend on global navigation satellite systems (GNSS) for position, navigation, and timing (PNT) information. Of these, the American Global Positioning System (GPS) is the most popular GNSS, with the terms often used interchangeably. But there are other GNSSs as well, like Europe’s Galileo, Russia’s GLONASS, China’s BeiDou and India’s NavIC. Hence, statement 1 is correct.

— These systems include ground infrastructure and satellite constellations that provide PNT information by determining the position of a GNSS signal receiver. Vessels are equipped with these receivers, and vehicles with navigational aids. While these systems have a high degree of accuracy, satellite navigation signals are weak and, therefore, vulnerable to interference.

— GPS jamming or spoofing are two deliberate types of cyberattacks on GNSS signals to disrupt or trick the navigation systems of vehicles. Despite being used synonymously, they refer to two different things. Hence, statement 2 is correct.

— GPS jamming involves the use of a device called a jammer to overpower weaker signals with ‘noise’ on the same frequency. GPS spoofing, on the other hand, mimics the GPS signal and provides the pilot (or captain) with false information about their actual location. Hence, statement 3 is correct.

— Of the two, spoofing is the more serious offence, disrupting signals and forcing pilots, for instance, to incorrectly account for factors such as altitude or terrain. Spoofing may tell an aircraft it is in a location it isn’t supposed to be in, and create confusion in the cockpit.

Therefore, option (c) is the correct answer.

Previous Daily Subject-Wise-Quiz

Daily Subject-wise quiz — History, Culture, and Social Issues (Week 148)

Daily subject-wise quiz — Polity and Governance (Week 153)

Daily subject-wise quiz —  Science and Technology (Week 152)

Daily subject-wise quiz — Economy (Week 151)

Daily subject-wise quiz — Environment and Geography (Week 152)

Daily subject-wise quiz – International Relations (Week 152)

Subscribe to our UPSC newsletter and stay updated with the news cues from the past week.

Stay updated with the latest UPSC articles by joining our Telegram channel – IndianExpress UPSC Hub, and follow us on Instagram and X.