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Home » UPSC Prelims Quiz » UPSC Prelims Quiz: September 24, 2025

UPSC Prelims Quiz: September 24, 2025

Q1. Consider the following statements:

1. SST-Bharat is planned as a fusion–fission hybrid reactor with a demonstration target around 2060.

2. In D–T fusion, tritium is largely bred from lithium blankets, as it is scarce in nature.

Which of the above statements is/are correct?

(a)

1 only

(b)

2 only

(c)

Both 1 and 2

(d)

Neither 1 nor 2

Explanation

Statement 1 – Correct: India’s roadmap proposes SST-Bharat, a superconducting tokamak hybrid reactor (~130 MW) with a demonstration timeline by 2060.

Statement 2 – Correct: Tritium is not naturally abundant; hence, fusion reactors use lithium-based blankets to breed tritium for the deuterium–tritium cycle.

Answer: (c) Both 1 and 2
Q2. India’s first overseas defence manufacturing facility has been set up in which country?
(a)

Egypt

(b)

Morocco

(c)

Kenya

(d)

South Africa

Explanation

The facility was inaugurated in Berrechid, Morocco, in September 2025.

It has been set up by Tata Advanced Systems Limited (TASL).

The plant will produce the indigenously developed Wheeled Armoured Platform (WhAP) for the Royal Moroccan Army.

This marks the first overseas defence manufacturing unit by an Indian company.

Answer: (b) Morocco
Q3. Consider the following projects:

1. Almatti Dam

2. Narayanpur (Basava Sagar) Dam

3. Priyadarshini Jurala Project

4. Somasila Project

5. Pulichintala Project

How many of the above are built on the Krishna River (including its main stem and direct tributaries)?

(a)

Two

(b)

Three

(c)

Four

(d)

Five

Explanation

Almatti Dam – Krishna main stem, Karnataka

Narayanpur (Basava Sagar) Dam – Krishna main stem, Karnataka

Priyadarshini Jurala Project – Krishna main stem, Telangana

Somasila Project – NOT on Krishna, it is on the Penna River, Andhra Pradesh

Pulichintala Project (K. L. Rao Sagar) – Krishna main stem, Andhra Pradesh

Answer: (c) Four
Q4. Consider the following pairs regarding the recipients of UNEP’s Young Champions of the Earth 2025 award and their innovations:
Recipient (2025)Innovation/Project
1. Jinali Mody (India)Eco-friendly leather made from banana crop waste
2. Joseph Nguthiru (Kenya)Biodegradable packaging developed from invasive water hyacinth
3. Noemi Florea (United States)Compact household system to recycle greywater into drinking water with low energy use

How many of the above pairs are correctly matched?

(a)

Only one

(b)

Only two

(c)

All three

(d)

None

Explanation

Pair 1 – Correct: Jinali Mody (India) → Banofi Leather, an alternative to leather using banana crop waste, reducing water use and chemical pollution.

Pair 2 – Correct: Joseph Nguthiru (Kenya) → HyaPak, turning invasive water hyacinth into biodegradable packaging and seedling wrappers.

Pair 3 – Correct: Noemi Florea (US) → Cycleau, a compact greywater reuse system, converting household wastewater into potable water.

Answer: (c) All three
Q5. Consider the following:

1. It is a mountain range of the Eastern Ghats.

2. It was declared a Biodiversity Heritage Site in 2022.

3. It houses Panchpandava temples and shrines dedicated to Lord Shiva.

The above statements describe which of the following?

(a)

Nallamala Hills

(b)

Mahendragiri Hills

(c)

Anantagiri Hills

(d)

Seshachalam Hills

Explanation

Statement 1 – Correct: Mahendragiri Hills are part of the Eastern Ghats, located in Gajapati district of Odisha.

Statement 2 – Correct: In 2022, the Odisha government declared Mahendragiri Hills a Biodiversity Heritage Site under the Biological Diversity Act, 2002.

Statement 3 – Correct: The hills are culturally significant as they house the Panchpandava temples and shrines dedicated to Lord Shiva, attracting pilgrims especially during Maha Shivaratri.

Thus, all the given statements correctly refer to the Mahendragiri Hills of Odisha.

Answer: (b) Mahendragiri Hills
Q6. Consider the following statements regarding quasi-moons:

1. Unlike Earth’s true moon, a quasi-moon is not gravitationally bound to Earth but instead orbits the Sun in a resonance similar to Earth’s orbit.

2. The recently identified quasi-moon 2025 PN7 has been orbiting near Earth for about 60 years.

Which of the statements given above is/are correct?

(a)

1 only

(b)

2 only

(c)

Both 1 and 2

(d)

Neither 1 nor 2

Explanation

Statement 1 – Correct: A quasi-moon differs from a true satellite because it does not orbit Earth directly. Instead, it orbits the Sun in a 1:1 resonance with Earth, following a similar orbital period but with a slightly different path. From Earth’s perspective, it appears to loop around in a retrograde motion, but it remains outside Earth’s Hill sphere.

Statement 2 – Correct: Astronomers recently confirmed the discovery of quasi-moon 2025 PN7, which has been in Earth’s vicinity for about 60 years.

Thus, both statements are correct.

Answer: (c) Both 1 and 2
A New “Quasi-Moon” Near Earth: 2025 PN7

What Is a Quasi-Moon?

A quasi-moon (or quasi-satellite) is an object that seems to orbit Earth, but in reality it orbits the Sun in a path very similar to Earth’s. It remains in a 1:1 orbital resonance with Earth—meaning it completes one orbit around the Sun in nearly the same time as Earth—but it is not gravitationally bound to Earth like the Moon. Because of this, it can drift into different co-orbital behaviors such as horseshoe or tadpole orbits over time.

From Earth, a quasi-moon can appear to loop around us in a complex path, but that is only a visual effect, not a true satellite orbit.

Discovery and Orbit of 2025 PN7

  • The asteroid 2025 PN7 was first observed on 2 August 2025 by the Pan-STARRS 1 telescope in Hawaii.
  • Archival images suggest it has been in a quasi-satellite orbit for about 60 years.
  • Orbital parameters:
    • Semi-major axis: ~1.003 AU
    • Eccentricity: ~0.108
    • Inclination: ~2°
  • Estimated diameter: ~19 meters (62 feet).
  • Expected to remain in this quasi-satellite state for roughly another 60 years, making its total quasi-satellite duration ~128 years.
  • Because of its faintness (magnitude ~26), it eluded detection until recently.

How Quasi-Moons Differ from True Moons

  • True moons are gravitationally bound to Earth and lie well within Earth’s Hill sphere.
  • Quasi-moons orbit the Sun, not Earth, but share Earth’s orbital period by resonance.
  • Over time, gravitational perturbations (from the Sun, planets, etc.) can shift them between orbital states (quasi-satellite, horseshoe, tadpole, etc.).

Why They Matter & Example Mission

  • They help us explore the dynamics of near-Earth orbits and resonances.
  • They are relatively accessible targets for spacecraft, useful for studying small-body composition and origins.
  • Tianwen-2 mission (China): aims to collect samples from the quasi-satellite asteroid 469219 Kamoʻoalewa (2016 HO₃).
    • Expected arrival: mid-2026.
    • Sample return: late 2027.
  • Kamoʻoalewa is among the more stable known quasi-satellites, considered a strong candidate for sample return.
  • Researchers hypothesize that some quasi-satellites, like Kamoʻoalewa (and possibly 2025 PN7), may be fragments ejected from the Moon long ago, though this remains under study.
Q7. With reference to the Maitri 2.0 Cross-Incubation Programme, consider the following statements:

1. It is a collaboration between India and Argentina focusing on renewable energy technologies.

2. It has been launched by NITI Aayog to promote defence startups.

3. Its main objective is to support space research and satellite development.

How many of the above statements are correct?

(a)

Only one

(b)

Only two

(c)

All three

(d)

None

Explanation

Statement 1 – Incorrect: Maitri 2.0 is not with Argentina; it is an India–Brazil programme in agritech.

Statement 2 – Incorrect: It was launched by the Indian Council of Agricultural Research (ICAR), not NITI Aayog.

Statement 3 – Incorrect: Its focus is on sustainable agriculture, digital technologies, and value-chain development, not space or satellites.

👉 Therefore, none of the statements is correct.

Answer: (d) None
Q8. With reference to neutrinos, consider the following statements:

1. They can be deflected by strong magnetic fields due to their spin.

2. They interact with matter only through weak nuclear force and gravity.

3. They travel at speeds less than that of light because of their tiny but non-zero mass.

4. They are the most abundant particles in the universe, even more than photons.

How many of the above statements are correct?

(a)

Only one

(b)

Only two

(c)

Only three

(d)

All four

Explanation

Statement 1 – Incorrect: Neutrinos have no electric charge and extremely tiny mass, hence they are not deflected by magnetic fields.

Statement 2 – Correct: Neutrinos interact only via weak nuclear force and gravity, making them extremely hard to detect.

Statement 3 – Correct: While previously thought to be massless and thus travel at the speed of light, it’s now established that neutrinos possess a small, non-zero mass. According to special relativity, particles with mass must travel slower than the speed of light, although this difference is incredibly slight for neutrinos and difficult to measure.

Statement 4 – Incorrect: Photons are the most abundant particles in the universe, neutrinos are second-most abundant.

Hence, only Statements 2 and 3 are correct.

Answer: (b) Only two
Q9. Consider the following statements:

1. The JUNO neutrino observatory in China is primarily designed to determine the relative masses of the three neutrino types.

2. The India-based Neutrino Observatory (INO) is located near the equator, giving it a unique advantage in studying atmospheric neutrinos compared to other global observatories.

Which of the above statements is/are correct?

(a)

1 only

(b)

2 only

(c)

Both 1 and 2

(d)

Neither 1 nor 2

Explanation

Statement 1 – Correct: JUNO’s main goal is to determine the neutrino mass hierarchy (i.e., which neutrino type is heavier/lighter).

Statement 2 – Correct: The INO site in Theni (Tamil Nadu) lies close to the equator, unlike most detectors at higher latitudes. This makes it globally unique in studying atmospheric neutrinos that pass through different paths inside the Earth.

Thus, both statements are correct.

Answer: (c) Both 1 and 2
Q10. Match List I (Neutrino Observatories) with List II (Distinct Features/Locations):
List I (Observatory)List II (Features/Functions)
A. JUNO – China1. Uses deep ice to capture Cherenkov radiation from neutrinos.
B. INO – India2. Located deep underground in Tamil Nadu’s Theni district, planned with a magnetized detector.
C. IceCube – Antarctica3. Aims to study neutrino mass hierarchy through precise oscillation measurements.
D. DUNE – USA4. A next-generation project designed for long-baseline neutrino experiments.

Select the correct answer:

(a)

A-2, B-3, C-4, D-1

(b)

A-3, B-2, C-1, D-4

(c)

A-4, B-1, C-2, D-3

(d)

A-1, B-4, C-3, D-2

Explanation

JUNO – China: The Jiangmen Underground Neutrino Observatory (JUNO) is a major experiment in China designed to measure the neutrino mass hierarchy and precisely determine oscillation parameters.

INO – India: The India-based Neutrino Observatory (INO) is a proposed project in the Theni district of Tamil Nadu. It plans to build a large, underground, magnetized iron calorimeter (ICAL) detector to study atmospheric neutrinos.

IceCube – Antarctica: The IceCube Neutrino Observatory is situated at the South Pole and uses thousands of sensors buried deep within the Antarctic ice sheet. These sensors detect Cherenkov radiation produced when neutrinos interact with the ice.

DUNE – USA: The Deep Underground Neutrino Experiment (DUNE) is a future long-baseline experiment that will send an intense neutrino beam from Fermilab in Illinois to a massive detector located 1,300 kilometers away in South Dakota.

Answer: (b) A-3, B-2, C-1, D-4