DAY – 74 : Insta 75 Days Revision Plan-2026 : PREVIOUS YEAR UPSC PAPER

Answer: D

Statement I: is incorrect

• Only VTOL (Vertical Take-Off and Landing) UAVs can perform vertical landing.
• Fixed-wing UAVs require runways or nets for landing and cannot land vertically.

Statement II: is incorrect

• Hovering is possible only in multirotor UAVs or VTOLs with rotors.
• Fixed-wing UAVs cannot hover in place as they depend on forward motion for lift.

Statement III: is incorrect

• UAVs may run on batteries, petrol, diesel, hydrogen fuel cells, or solar power.
• Not all types can rely solely on batteries due to size, range, and payload requirements — especially large or military-grade UAVs.

None of the three statements are correct, as each overgeneralizes across all UAV types, which differ significantly in design and capabilities.

Correct answer: (d) None.

Answer: C

Battery Cathode Composition:

• Cobalt (I) – Commonly used in lithium cobalt oxide (LCO) and nickel cobalt manganese (NCM) cathodes.
• Lithium (III) – Present in the cathode material in lithium-based compounds, e.g., LiCoO₂, LiFePO₄, LiNiMnCoO₂, etc.

• Nickel (IV) – Used in nickel-rich cathodes like NCA (Nickel Cobalt Aluminium) and NCM.
• Graphite (II) – This is not used in the cathode. It is used in the anode of lithium-ion batteries.
• Cobalt, Lithium, and Nickel are commonly used in EV battery cathodes.
• Graphite is used in anodes, not cathodes.

Thus, only three of the four listed elements are used in cathodes.

Answer: B

L-20, HMX, and LLM-105 are all high-energy explosives used in advanced military applications.

1. CL-20 (Hexanitrohexaazaisowurtzitane)
   • One of the most powerful non-nuclear explosives
   • Developed for enhanced performance in warheads, bombs, and propulsion systems.
2. HMX (High Melting Explosive or Octogen)
   • A powerful secondary explosive, more energetic than RDX.
   • Used in military-grade munitions, including detonators, shaped charges, and solid rocket boosters.
3. LLM-105 (Triaminotrinitrobenzene derivative)
   • A newer insensitive high explosive developed by Lawrence Livermore National Laboratory.
   • Offers high power with increased safety for handling and storage.

Answer: D

Statement I: Correct.

• Monoclonal antibodies are laboratory-produced molecules designed to serve as substitute antibodies. They can mimic the immune system’s ability to fight off harmful pathogens such as viruses.

Statement II: Correct.

• Monoclonal antibodies are highly specific — they bind to a single type of antigen, typically on the surface of pathogens or infected cells. This specificity allows them to neutralize viruses, mark cells for destruction, or block receptor-ligand interactions, thereby stimulating immune responses.

Statement III: Correct.

• Monoclonal antibodies have been experimentally and compassionately used in treating Nipah virus infections. For instance, m102.4, a monoclonal antibody, has shown promise in treating Nipah virus in non-human primate studies and has been used in some emergency human cases.

Hence, the correct answer is: (d) I, II and III.

Answer: C

• Statement I: Correct. India did not sign the COP28 Declaration on Climate and Health.
• Statement II: Incorrect. The declaration is non-binding and does not mandate decarbonisation.
• Statement III: Correct. India cited concerns that rapid decarbonisation could affect the functioning and resilience of its healthcare system, especially in remote and underserved areas.

Therefore, Statement III is correct and it explains Statement I.
Only one of Statements II and III is correct, and that one (III) explains Statement I.

Answer: A

The correct answer is: (a) The Asian Development Bank (ADB).

• At COP28, the Asian Development Bank launched the Nature Solutions Finance Hub for Asia and the Pacific. This initiative aims to attract at least $2 billion into investment programs that incorporate nature-based solutions, particularly focusing on capital markets and other sources of private capital.
• The hub is designed to deploy a range of financing measures to reduce risks in nature-based solutions projects, such as guarantees, impact-linked payments, and blended finance options. It targets about $1 billion in de-risking funds from global development partners, with advanced discussions underway with several entities
• Therefore, the Asian Development Bank (ADB) is the organization that launched the Nature Solutions Finance Hub for Asia and the Pacific.

Answer: D

• Statement I – Incorrect:
  The Peacock tarantula (Poecilotheria metallica), also known as the Gooty tarantula, is not a crustacean — it is a spider, i.e., an arachnid. Moreover, it is carnivorous, feeding on insects and small animals, not omnivorous.
• Statement II – Correct:
  It is endemic to a very limited area — specifically, the Eastern Ghats of Andhra Pradesh, India. Its natural range is highly restricted to certain forest patches.
• Statement III – Correct:
  The Gooty tarantula is an arboreal species, meaning it lives in trees. It typically stays in tree holes, spinning webs inside for shelter and hunting.

Answer: C

• Statement I. Correct.
  These were key features of the programme. People were urged to boycott British institutions, including courts and foreign goods like Manchester cloth.
• Statement II. Correct
  Non-violence (ahimsa) was a core principle of the movement, as emphasized by Gandhi.
• Statement III. Incorrect
  The actual programme called for surrendering titles and honours, not just avoiding their use. Many returned titles like “Kaiser-i-Hind”.
• Statement IV. Correct
  The programme encouraged setting up village Panchayats as alternatives to colonial judicial systems.

Answer: A

Mattavilasa (“lover of the sport of intoxication”) – This was a title used by Mahendravarman I reflecting his authorship of the satirical Sanskrit play Mattavilasa Prahasana, which critiques religious hypocrisy.

• Vichitrachitta (“curious-minded” or “of artistic tastes”) – This refers to his interest in art, architecture, and music, especially visible in the rock-cut temples of Mahabalipuram.
• Gunabhara – This title also relates to his literary and scholarly accomplishments.

Who was Mahendravarman I?

• He was a Pallava ruler (c. 600–630 CE) and the father of Narasimhavarman I.
• A patron of Shaivism and fine arts, he contributed significantly to early Dravidian temple architecture.

Answer: B

1. Asmaka – Godavari:
   This is correctly matched. Asmaka was located in the Deccan region, particularly in present-day Maharashtra and Telangana, through which the Godavari river flows.
2. Kamboja – Vipas:
   This is incorrectly matched. Kamboja was situated in the northwestern region of the Indian subcontinent (modern Afghanistan–Tajikistan border), while the Vipas (Beas) river flows in present-day Punjab and Himachal Pradesh.

III. Avanti – Mahanadi:
This is incorrectly matched. Avanti was located in the Malwa region of present-day western Madhya Pradesh, and the main rivers in this region were the Chambal and Shipra. The Mahanadi flows in Chhattisgarh and Odisha, which is east of Avanti.

1. Kosala – Sarayu:
   This is correctly matched. Kosala was located in eastern Uttar Pradesh, with Ayodhya as its capital. The Sarayu river flows through this region.

Final answer: (b) Only two

Answer: (a)

Explanation:
The passage mainly focuses on the need for an institutional and policy-based mechanism for equitable water sharing among States. It specifically highlights objective criteria and basin-based allocation. Therefore, the most rational and immediate solution is to establish a national legal and policy framework for water allocation.

Options (b) and (c) involve large-scale engineering projects, which are long-term and complex solutions rather than immediate institutional measures. Option (d) addresses reduction of demand, whereas the passage primarily discusses fair allocation among stakeholders.

Answer: (b) 19

Explanation:
Let:

• singles = s
• fours = f
• sixes = x

Then:

s + 4f + 6x = 25

We count all possible non-negative integer combinations.

Possible values of sixes:

• If x = 0:
  Remaining runs = 25
  Number of possible values of f = 0 to 6
  → 7 combinations
• If x = 1:
  Remaining runs = 19
  f = 0 to 4
  → 5 combinations
• If x = 2:
  Remaining runs = 13
  f = 0 to 3
  → 4 combinations
• If x = 3:
  Remaining runs = 7
  f = 0 or 1
  → 2 combinations
• If x = 4:
  Remaining runs = 1
  f = 0 only
  → 1 combination

Total combinations:

7 + 5 + 4 + 2 + 1 = 19

Hence, the correct answer is (b).

Answer: (d) 45

Explanation:
We consider the worst possible case.

First, Raj may pick all non-red shoes:

• White shoes = 9 pairs = 18 shoes
• Black shoes = 8 pairs = 16 shoes

Total non-red shoes = 34

Now only red shoes remain.

Among red shoes, he may still avoid forming a matching pair by picking only left shoes (or only right shoes).

Since there are 10 left red shoes:

• He may pick all 10 left red shoes without getting a matching pair.

Total shoes picked so far:

34 + 10 = 44

The next shoe picked must be a right red shoe, which will complete a matching red pair.

Therefore, the maximum number of shoes required is 45.

Answer: (b) 9

Explanation:
To obtain 64 identical smaller cubes, the cube must be divided equally along length, breadth and height.

Since:

64 = 4 × 4 × 4

the cube must be divided into 4 equal parts along each dimension.

To divide one dimension into 4 equal parts:

• 3 cuts are required.

Therefore:

• 3 cuts along length
• 3 cuts along breadth
• 3 cuts along height

Total cuts required:

3 + 3 + 3 = 9

Hence, the minimum number of cuts required is 9.

Answer: (c) 20%

Explanation:
Work done depends on:

Number of men × Number of days

Let the original number of men be M.

Initial work:

M × 6k

Let the new number of men be N.

Required work:

N × 5k

Since the total work remains constant:

M × 6k = N × 5k

Cancelling k from both sides:

6M = 5N

Therefore:

N = 6M/5

Increase in number of men:

(6M/5 − M) = M/5

Percentage increase:

(M/5 ÷ M) × 100 = 20%

Hence, the required increase is 20%.