DAY – 20 : Insta 75 Days Revision Plan-2026 : SCIENCE & TECHNOLOGY

Answer:  (c)

Explanation:

• Statement 1 is correct: NavIC is designed with a 7-satellite constellation.
  • 3 satellites are placed in Geostationary Orbit (GEO) (appearing fixed over the equator).
  • 4 satellites are in Geosynchronous Orbit (GSO)

• Note: ISRO is currently expanding this to a 12-satellite constellation to improve global reach and signal frequency (L1 band).

• Statement 2 is correct: NavIC provides two types of services: Standard Positioning Service (SPS) for all users and Restricted Service (RS) for authorized users (military). It offers an accuracy of better than 20 meters within the Primary Service Area, which covers the Indian landmass and an extended region of up to 1500 km beyond its boundaries.
• Statement 3 is incorrect: While earlier integration was slow, global chipset manufacturers like Qualcomm (Snapdragon), MediaTek, and Broadcom have already integrated NavIC support into their commercial chips. Many international smartphone brands now come NavIC-ready out of the box.

Answer:  (d)

Explanation:

• Statement (a) is incorrect: The CES is not for landing. It is an emergency system active during the launch and ascent phase. Its job is to pull the crew module away from the rocket if something goes wrong during the high-pressure climb to space.
• Statement (b) is incorrect: The CES has nothing to do with the Chandrayaan-3 (Lunar) mission. It was specifically tested during the TV-D1 (Test Vehicle Development Flight-1) in October 2023, where a single-stage liquid rocket was used to simulate an abort scenario at Mach 1.2.
• Statement (c) is incorrect: While it can function on the launch pad (Pad Abort), it is designed to be active throughout the entire atmospheric phase of the flight. It must be able to handle Max-Q (the point of maximum aerodynamic pressure) and various altitudes.
• Statement (d) is correct: The CES is essentially a rocket on top of a rocket. It uses five solid-fuel motors (High altitude Escape Motor, Low altitude Escape Motor, Jettison Motor, and Pitch/YAW motors) to provide the instant, massive thrust required to accelerate the Crew Module away from the main launcher within seconds.

Answer:   (b)

Explanation:

• Statement 1 is incorrect: The PUNCH (Polarimeter to Unify the Corona and Heliosphere) mission is a NASA mission, not a docking demonstration. Its objective is to image the solar wind and the Sun’s outer atmosphere (the corona) to understand how they transition into the heliosphere. The technology demonstration for satellite docking in the Indian context is actually the SPADEX (Space Docking Experiment) mission by ISRO.
• Statement 2 is correct: Aditya-L1 is India’s first dedicated solar observatory. It is placed in a halo orbit around the Lagrange Point 1 (L1) of the Sun-Earth system, which is about 1.5 million km from Earth.
• The primary advantage of L1 is that it provides a continuous, uninterrupted view of the Sun without any occultation or eclipses, which would otherwise occur if the satellite were in a Low-Earth Orbit (LEO).

Answer:  (c)

Explanation:

• Statement-I is correct: The BioSaarthi initiative is a focused mentorship program under the Biotechnology Industry Research Assistance Council (BIRAC). Its primary goal is to provide high-level, hand-holding support to Indian biotech startups. By providing indigenous expertise and clinical/regulatory guidance, it aims to build a robust local ecosystem, thereby reducing the necessity for Indian startups to look toward foreign incubators for specialized knowledge and global networking.
• Statement-II is incorrect: BioSaarthi is not a funding scheme. It is a Mentorship While BIRAC has other schemes for funding (like BIG – Biotechnology Ignition Grant, SEED Fund, or LEAP Fund), BioSaarthi specifically matches startups with Bio-Saarthis (mentors) who have expertise in regulatory pathways, intellectual property, and market access. It does not provide direct seed funding or act as a venture capital/angel network.

Answer:   (a)

Explanation:

• Statement 1 is correct: DNA and RNA are named after their sugars. Deoxyribose (in DNA) literally means ribose minus one oxygen. Ribose (in RNA) has a hydroxyl group (-OH) at the 2′ carbon, whereas deoxyribose has only a hydrogen atom (-H) at that position. This one additional oxygen in RNA makes it much more chemically reactive.
• Statement 2 is incorrect: While both use four bases, they are not the same set.
  • DNA uses Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).
  • RNA uses Adenine (A), Guanine (G), Cytosine (C), and Uracil (U).

• Statement 3 is incorrect: RNA is generally single-stranded, but this makes it less chemically stable than DNA. The double-helix structure of DNA protects the nitrogenous bases inside, and the lack of the extra oxygen atom in the deoxyribose sugar makes DNA resistant to hydrolysis. RNA’s single-stranded nature and its reactive ribose sugar make it prone to breaking down quickly, which is why it is used for temporary messaging (mRNA) rather than long-term storage.

Answer:  (a)

Explanation:

• Statement 1 is correct: CAR-T therapy is a classic example of Adoptive Cell Transfer (ACT). In this process, the patient’s own T-cells (a type of white blood cell) are collected, genetically modified in a laboratory to better recognize and kill cancer cells, and then adopted back into the patient’s body. Because these cells continue to grow and multiply inside the patient, they are often referred to as a living drug.
• Statement 2 is incorrect: The genetic modification in CAR-T therapy is typically performed ex vivo (outside the body), not in vivo.

1. T-cells are first removed from the patient’s blood through a process called apheresis.
2. In a specialized lab, a viral vector (like a lentivirus) is used to insert the Chimeric Antigen Receptor gene into the T-cells.
3. These cells are then expanded (multiplied) into the millions before being infused back into the patient’s bloodstream.

Answer:   (c)

Explanation:

• Pair 1 is correctly matched: Desert Knight is a recent and significant trilateral air exercise involving the Indian Air Force (IAF), the French Air and Space Force, and the United Arab Emirates (UAE) Air Force. It is conducted over the Arabian Sea to enhance interoperability and operational coordination.
• Pair 2 is correctly matched: Eastern Bridge is a bilateral air exercise between the Indian Air Force and the Royal Air Force of Oman. It serves to strengthen regional maritime security and air defense cooperation.
• Pair 3 is incorrectly matched: Cope India is a high-profile bilateral air exercise between the Indian Air Force and the United States Air Force (USAF). The major air exercise conducted between India and the United Kingdom is known as Indradhanush.
• Pair 4 is correctly matched: VINBAX (Vietnam-India Bilateral Army Exercise) is an annual exercise between the Indian Army and the Vietnam People’s Army. It focuses on the employment and deployment of an Engineer Company and a Medical Team as part of United Nations Contingents.

Answer:  (b)

Explanation:

• Statement-I is correct: Traditional rockets are heavy because they must carry both fuel and an oxidizer (like liquid oxygen) to function in the vacuum of space. Scramjets are Air-Breathers. They scoop up oxygen from the atmosphere while flying at high speeds. Because they don’t carry the dead weight of an oxidizer, they have a much higher Specific Impulse (efficiency), allowing for more payload or longer range within the atmosphere.
• Statement-II is correct: This is the technical definition of a Scramjet (Supersonic Combustion Ramjet). In a regular Ramjet, the incoming supersonic air is slowed down to subsonic speeds before combustion. In a Scramjet, the air remains at supersonic speeds throughout the engine. Maintaining a flame in a supersonic wind is often compared to lighting a matchstick in a hurricane.

While both are true, Statement-II describes the internal mechanics (supersonic airflow), whereas Statement-I describes the operational advantage (no onboard oxidizer). The reason Scramjets are more efficient (S-I) is specifically because they are Air-Breathing systems, not because the combustion happens at supersonic speeds. A subsonic Ramjet is also more efficient than a rocket for the same reason (no oxidizer), even though its combustion is subsonic.

Answer:  (a)

Explanation:

• Prithvi: This is a Short-Range Ballistic Missile (SRBM). It was the first missile developed under the IGMDP (Integrated Guided Missile Development Programme). Its range is typically between 150 km and 350 km.
• Agni V: This is a family/series of missiles. While Agni-I to Agni-IV are Short to Intermediate range, Agni-V is India’s first acknowledged Intercontinental Ballistic Missile (ICBM) with a range of over 5,000–5,500 km. Since Agni represents the series that includes an ICBM, it counts as one in this context.
• Trishul: This was developed as a Short-Range Surface-to-Air Missile (SAM). It is not a ballistic missile and has a very short range (approx. 9 km).
• Nag: This is a third-generation Anti-Tank Guided Missile (ATGM) with Fire and Forget capability. Its range is limited to about 4–7 km.
• BrahMos: This is a Supersonic Cruise Missile (a joint venture with Russia). Even in its extended-range versions, it is not a ballistic missile and does not fall into the ICBM category (its range is approx. 290 km to 450+ km).

Answer:   (b)

Explanation:

• Statement 1 is incorrect: While the initiative focuses on agriculture, it was not launched by the Ministry of Agriculture and Farmers’ Welfare. It is an initiative of APEDA (Agricultural and Processed Food Products Export Development Authority), which operates under the Ministry of Commerce & Industry. Its primary goal is export-acceleration and startup support, rather than just the promotion of organic farming (though organic products are a sub-focus).
• Statement 2 is correct: One of the core objectives of the BHARATI (Bharat’s Hub for Agritech, Resilience, Advancement and Incubation for Export Enablement) initiative is to scale India’s agri-food exports to a target of $50 billion by 2030. It aims to achieve this by empowering 100 specialized agri-tech and agri-food startups.

Answer: (c) 720

Detailed Explanation:

Let cost price of first chair = x
Then second chair = 1200 − x

First chair sold at 20% loss → SP = 0.8x
Second chair sold at 20% gain → SP = 1.2 × (1200 − x)

Since selling prices are equal:
0.8x = 1.2(1200 − x)

0.8x = 1440 − 1.2x
Add 1.2x to both sides:
2x = 1440
x = 720

So, cost price of first chair = 720

Answer: (b) 400

Detailed Explanation:

Marked Price = 560

Discount = 20% → Selling Price = 560 × 0.8 = 448

Profit = 12% →
SP = CP × 1.12

So,
CP = 448 ÷ 1.12 = 400

Answer: (c)

Detailed Explanation:

Check Statement 1 alone:
Let CP = 100 → MP = 140
No info on discount → cannot find SP → insufficient

Check Statement 2 alone:
Only discount given → no CP or MP → insufficient

Use both together:
CP = 100 → MP = 140
Discount 15% → SP = 140 × 0.85 = 119

Profit = 119 − 100 = 19%

Question: Is profit > 20%? → NO

Since definite answer is obtained → sufficient

Answer: (b) 400

Detailed Explanation:

Let CP = 100x
Then SP = 120x

New CP = 90x
New SP = 120x − 30

Given: Profit = 25%
So,
New SP = 1.25 × 90x = 112.5x

Equate:
120x − 30 = 112.5x

120x − 112.5x = 30
7.5x = 30
x = 4

CP = 100 × 4 = 400

Correct Answer: (b)

Explanation:

The passage presents a dualistic view of the gig economy, contrasting its marketed benefits with its structural flaws. While it acknowledges flexibility and autonomy, the author uses however to pivot toward the erosion of labor protections and precarious existence. Option (b) is the most accurate because it captures this trade-off—the link between independence and the loss of security. Option (a) is too positive, option (c) introduces innovation (not mentioned in the text), and option (d) is an extreme action-oriented conclusion that the passage itself does not explicitly demand, making (b) the most balanced central idea.