Q1. With reference to the NASA-ISRO Aperture Radar (NISAR) mission Synthetic and its launch, consider the following statements:
1. The NISAR satellite was launched aboard a GSLV rocket into a Sun-synchronous orbit for the first time.
2. Prior to this, ISRO had never placed any satellite into a Sun-synchronous orbit.
3. The NISAR satellite was placed in an orbit with an inclination greater than 98°, suitable for Earth observation.
Which of the statements given above is/are correct?
(a) 1 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3
Explanation:
Statement 1 – Correct.
The GSLV-F16 launch of NISAR on July 30, 2025, was the first time a GSLV placed a satellite into a Sun-synchronous orbit.
Statement 2 – Incorrect.
This is incorrect. ISRO has previously placed many satellites into Sun-synchronous orbits, the first being IRS-1A in 1988.
Statement 3 – Correct.
This is correct. NISAR was placed in a Sun-synchronous orbit at an altitude of 747 km with an inclination of 98.4°, which is typical for Earth observation missions and ensures global coverage.
Correct Answer: (b) 1 and 3 only
Q2. With reference to Sun-synchronous and polar orbits, consider the following statements:
1. A Sun-synchronous orbit is a type of polar orbit.
2. Satellites in Sun-synchronous orbit appear at the same position relative to the Sun during each pass.
3. Polar orbits are generally placed at altitudes above 2000 km.
4. Both Sun-synchronous and polar orbits allow satellites to pass over or near Earth’s poles.
Which of the above statements are correct?
(a) 1, 2 and 4 only
(b) 1, 3 and 4 only
(c) 2 and 3 only
(d) 1, 2, 3 and 4
Explanation:
Statement 1 – Correct.
Sun-synchronous orbits are a special kind of polar orbit, optimized so the satellite maintains a consistent local solar time over every part of Earth it passes.
Statement 2 – Correct.
SSOs maintain a fixed angle with respect to the Sun, so satellites appear at the same position relative to the Sun on each orbit.
Statement 3 – Incorrect.
Polar orbits typically have altitudes between 200 and 1,000 km, with Sun-synchronous orbits commonly ranging from about 600 to 800 km. They are classified as low Earth orbits, not above 2,000 km.
Statement 4 – Correct.
Both orbit types involve satellites that pass over or near the Earth’s poles, enabling global Earth coverage.
Correct Answer: (a) 1, 2 and 4 only
Q3. With reference to the NISAR satellite mission, consider the following statements:
1. It is the first satellite to use both L-band and S-band synthetic aperture radars.
2. The satellite can detect surface movements even during cloudy conditions and nighttime.
3. It is designed primarily for oceanographic research and weather forecasting.
4. The mission involves collaborative ground support from both India and the United States.
Which of the above statements are correct?
(a) 1, 2 and 4 only
(b) 1 and 3 only
(c) 2, 3 and 4 only
(d) 1, 2, 3 and 4
Explanation:
Statement 1 – Correct.
NISAR is the first satellite to use both L-band (NASA) and S-band (ISRO) SAR systems in one platform.
Statement 2 – Correct.
Synthetic Aperture Radar (SAR) can penetrate clouds and work at night, enabling it to track changes with centimeter-level precision.
Statement 3 – Incorrect.
NISAR is not designed primarily for oceanographic or weather forecasting; its core objectives include land deformation, disasters, ecosystem changes, and ice monitoring.
Statement 4 – Correct.
The mission is a joint effort, with both NASA and ISRO collaborating on development, satellite operations, and data handling. Ground stations and mission operations are shared between both agencies.
Correct Answer: (a) 1, 2 and 4 only
India’s First GSLV Launch to Sun-Synchronous Orbit with NISAR
A major milestone in India’s space journey was achieved on July 30, 2025, when the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite was successfully placed into a Sun-synchronous orbit (SSO) using the GSLV-F16 rocket. This marks the first-ever use of the GSLV series for inserting a satellite into this type of orbit—a task previously handled by ISRO’s PSLV rockets.
What Is a Sun-Synchronous Orbit?
A Sun-synchronous orbit (also called heliosynchronous) is a nearly polar path around the Earth. A satellite in this orbit passes over the same spot on Earth at the same local solar time every day. This helps in capturing consistent lighting conditions, making it ideal for Earth observation.
Historic GSLV-F16 Launch
- The GSLV-F16 lifted off from the Satish Dhawan Space Centre, Sriharikota.
- It carried the 2,392 kg NISAR satellite and placed it into a 747 km-high Sun-synchronous orbit with a 98.4° inclination.
- This was the first time GSLV was used for such an orbit, expanding its capability beyond geostationary missions.
What Is NISAR?
NISAR is a collaborative mission between NASA and ISRO to observe changes on Earth with high accuracy. It is the first satellite to use both L-band and S-band synthetic aperture radars (SAR).
Key Features of NISAR
- Dual Radar System:
• NASA provided the L-band radar and core data systems.
• ISRO supplied the S-band radar, satellite body, and launch services. - Orbit and Coverage:
• Orbits Earth at 747 km altitude.
• Has a 12-meter deployable mesh antenna.
• Captures full-Earth images every 12 days, unaffected by clouds or darkness. - Data Generation:
• Can produce up to 80 terabytes of data per day.
• Data is freely available, with rapid release during disasters. - Scientific Goals:
• Track ecosystem changes, ice-sheet loss, earthquakes, volcanoes, landslides, and ground movements.
• Supports climate change studies, disaster response, agriculture, and natural resource management. - Ground Support:
• Both US and Indian ground stations help in receiving and distributing the satellite data to users around the world.
Q4. With reference to India’s exports to the United States by 2024, consider the following statements:
1. Electrical and electronic equipment formed the highest‑value export category from India to the US.
2. Generic medicines are a minor component of India’s pharmaceutical exports to the US.
3. India has the highest number of US FDA‑approved manufacturing plants outside the United States.
4. Precious stones and metals ranked below pharmaceuticals in terms of export value.
Which of the above statements are correct?
(a) 3 only
(b) 2 and 4 only
(c) 1, 3 and 4 only
(d) 1, 2 and 4 only
Explanation
Statement 1 – Incorrect.
The top exported category from India to the US in 2024 was “Pearls, precious stones & metals” (including diamonds, gold, etc.) with a value of $10.17 billion, followed by “Electrical & Electronic Equipment” at $9.89 billion.
Statement 2 – Incorrect.
Generic medicines are actually the major component of India’s pharmaceutical exports to the US. India is the largest supplier of generics to the US, and generics account for a significant majority of these exports.
Statement 3 – Correct.
India leads the world in the number of US FDA-approved pharmaceutical manufacturing plants outside the United States, with recent counts exceeding 262 such facilities (and some sources citing over 700 total FDA-compliant facilities).
Statement 4 – Incorrect.
In 2024, precious stones and metals were exported to the US at a higher value ($10.17 billion) than pharmaceuticals ($7.55–8.10 billion).
Correct Answer: (a) 3 only
Q5. With reference to Ramsar Sites in India as of August 2025, consider the following statements:
1. Menar Wetland in Rajasthan was designated a Ramsar Site prior to Udhwa Lake in Jharkhand.
2. Among the newly added Ramsar Sites in 2025, only one state has more than one site in the list.
3. Tamil Nadu has more Ramsar Sites than any other state in India.
4. India now has more Ramsar Sites than the United Kingdom.
How many of the above statements are correct?
(a) Only one
(b) Only two
(c) Only three
(d) All four
Explanation
Statement 1 – Incorrect
Menar Wetland in Rajasthan: Designated on 19 February 2025.
Udhwa Lake in Jharkhand: Designated on 8 January 2024.
Menar was designated after Udhwa Lake, so this statement is incorrect.
Statement 2 – Incorrect
Newly added in 2025:
• Sakkarakottai Bird Sanctuary (Tamil Nadu)
• Therthangal Bird Sanctuary (Tamil Nadu)
• Khecheopalri Wetland (Sikkim)
• Udhwa Lake (Jharkhand)
• Khichan (Rajasthan)
• Menar (Rajasthan)
Both Tamil Nadu and Rajasthan each had two new sites in 2025. So, this statement is incorrect.
Statement 3 – Correct
Tamil Nadu indeed has the highest number of Ramsar Sites among Indian states — 20 as of August 2025.
Statement 4 – Incorrect
India has 91 Ramsar Sites, while the United Kingdom has 176, which is the highest globally. India ranks third, not first.
Correct Answer: (a) Only one
Q6. Which one of the following pairs of Ramsar Sites and their corresponding states is correctly matched, as per the designations up to August 2025?
(a) Khecheopalri Wetland – Arunachal Pradesh
(b) Sakkarakottai Bird Sanctuary – Kerala
(c) Khichan Wetland – Rajasthan
(d) Udhwa Lake – Chhattisgarh
Explanation
Let’s evaluate each option:
• (a) Khecheopalri Wetland – Arunachal Pradesh
Incorrect. Khecheopalri is located in Sikkim, not Arunachal Pradesh.
• (b) Sakkarakottai Bird Sanctuary – Kerala
Incorrect. It is in Tamil Nadu, not Kerala.
• (c) Khichan Wetland – Rajasthan
Correct. Khichan Wetland is located in Rajasthan, specifically near Phalodi. It was designated as a Ramsar Site in 2025 and is renowned for hosting large flocks of migratory demoiselle cranes each year.
• (d) Udhwa Lake – Chhattisgarh
Incorrect. Udhwa Lake is located in Jharkhand, not Chhattisgarh.
Answer: (c) Khichan Wetland – Rajasthan
Ramsar Sites in India (as of August 2025)
- Total sites: India has 91 Ramsar Sites, which are wetlands of international importance under the Ramsar Convention.
- Recent additions:
- June 2025: Khichan (Phalodi) and Menar (Udaipur), both in Rajasthan
- February 2025: Udhwa Lake (Jharkhand), Khecheopalri Wetland (Sikkim), Sakkarakottai Bird Sanctuary and Therthangal Bird Sanctuary (both in Tamil Nadu)
- State with most sites: Tamil Nadu leads with 20 Ramsar Sites.
- Total area covered: Over 1.36 million hectares.
Highest Number of Ramsar Sites in Asia
- India ranks first in Asia with 91 Ramsar Sites.
- Global ranking: India is third globally, after:
- United Kingdom – 176 sites
- Mexico – 144 sites
Q7. Consider the following facts:
1. It is a constitutional federation comprising seven administrative units.
2. It borders only Saudi Arabia and Oman by land.
3. Its territory is located along both the Persian Gulf and the Gulf of Oman.
4. The Tropic of Cancer passes through one of its administrative regions.
5. It lies near the Strait of Hormuz, a major chokepoint for global oil trade.
The above facts are associated with which one of the following countries?
(a) Kuwait
(b) Qatar
(c) United Arab Emirates
(d) Iran
Explanation
The country described by the provided facts is the United Arab Emirates (UAE). Here’s how each fact aligns:
1. The UAE is a constitutional federation made up of seven emirates: Abu Dhabi, Dubai, Sharjah, Ajman, Umm Al Quwain, Ras Al Khaimah, and Fujairah.
2. The UAE shares land borders exclusively with Saudi Arabia and Oman.
3. The UAE’s coastline stretches along the Persian Gulf, with its eastern emirate, Fujairah, facing the Gulf of Oman.
4. The Tropic of Cancer passes through the UAE.
5. The UAE lies adjacent to the Strait of Hormuz, with its northern emirates (especially Ras Al Khaimah and Fujairah) near this vital maritime chokepoint.
Correct answer: (c) United Arab Emirates