Q20. In which state is the Satish Dhawan Space Centre situated?
[RRB NTPC 2016, General Awareness]
A. Uttar Pradesh
B. Madhya Pradesh
C. Andhra Pradesh
D. Tamil Nadu
Answer: C. Andhra Pradesh
Explanation: The Satish Dhawan Space Centre is located at Sriharikota in Andhra Pradesh. Its launch complexes support India’s orbital rocket missions, including PSLV, GSLV, LVM3 and recent small-satellite launch initiatives.
Q19. Which one is a satellite-based augmentation system?
[RRB NTPC 2016, General Awareness]
A. INSAT
B. GAGAN
C. GSAT
D. SARAL
Answer: B. GAGAN
Explanation: GAGAN, developed by ISRO and the Airports Authority of India, augments satellite navigation signals using ground stations and geostationary satellites. It improves accuracy and integrity, particularly for aircraft navigation and safety.
Q18. Which activities use Indian Remote Sensing satellites:
1. crop assessment,
2. groundwater prospecting,
3. mineral exploration,
4. telecommunications,
5. traffic studies?
[UPSC CSE Prelims 2015, GS Paper I]
A. 1, 2 and 3 only
B. 4 and 5 only
C. 1 and 2 only
D. All five
Answer: A. 1, 2 and 3 only
Explanation: The IRS series is designed primarily for Earth observation and natural-resource applications, including agriculture, groundwater and mineral mapping. Dedicated communication satellites, rather than IRS spacecraft, perform telecommunications services.
Q17. Which two satellites among GSAT-2, GSAT-4, GSAT-5P and GSAT-12 failed to reach their intended orbits?
[RPSC RAS Prelims 2015 (2013 Re-examination)]
A. GSAT-2 and GSAT-4
B. GSAT-4 and GSAT-5P
C. GSAT-5P and GSAT-12
D. GSAT-12 and GSAT-2
Answer: B. GSAT-4 and GSAT-5P
Explanation: GSAT-4 was lost during the unsuccessful GSLV-D3 flight in April 2010, and GSAT-5P was lost when GSLV-F06 failed in December 2010. GSAT-2 and GSAT-12 were successfully placed into orbit on separate launches.
Q16. Which spacecraft–purpose pairs are correctly matched:
1. Cassini–Huygens/Venus,
2. MESSENGER/Mercury,
3. Voyager 1 and 2/outer solar system?
[UPSC CSE Prelims 2014, GS Paper I]
A. 1 only
B. 2 and 3 only
C. 1 and 3 only
D. All three
Answer: B. 2 and 3 only
Explanation: Cassini–Huygens explored Saturn and its moon Titan rather than Venus. NASA’s MESSENGER mapped Mercury, while Voyager 1 and 2 explored the outer solar system. Therefore only pairs 2 and 3 are correct.
Q15. The Indian GSAT-7 satellite was developed primarily for which purpose?
[RPSC RAS Prelims 2013, General Knowledge]
A. Weather forecasting
B. Military communication
C. Mars exploration
D. Lunar mapping
Answer: B. Military communication
Explanation: GSAT-7, nicknamed Rukmini, is a dedicated communications satellite supporting Indian defence requirements, particularly naval operations. It provides secure links across a wide maritime area, unlike Earth-observation, weather or planetary exploration satellites.
Q14. Which statements support the expansion of the universe:
1. observations of cosmic microwave background radiation;
2. observations of redshift in distant galaxies;
3. movement of asteroids in the Solar System;
4. occurrence of supernova explosions?
[UPSC CSE Prelims 2012, General Studies]
A. 1 and 2 only
B. 2 only
C. 1, 3 and 4
D. None of the above
Answer: A. 1 and 2 only
Explanation: The cosmic microwave background and redshift of distant galaxies support the expanding-universe model. Motion of asteroids within the Solar System is not evidence of cosmic expansion. The mere occurrence of supernova explosions is also not proof; distance–redshift measurements of supernovae are relevant.
Q13. Why does an artificial satellite in orbit not simply fall to Earth?
[UPSC CSE Prelims 2011, GS Paper I]
A. Earth exerts no attraction
B. The Moon cancels Earth’s gravity
C. Earth supplies a constant orbital speed
D. Earth’s attraction provides acceleration for orbital motion
Answer: D. Earth’s attraction provides acceleration for orbital motion
Explanation: Gravity continuously accelerates the satellite toward Earth, bending its path into an orbit while its tangential speed carries it forward. It remains in free fall around the planet instead of dropping straight to the surface.
Q12. A geostationary telecommunications satellite must have which properties:
1. geosynchronous period,
2. circular orbit,
3. equatorial orbit,
4. altitude 22,236 km?
[UPSC CSE Prelims 2011, GS Paper I]
A. 1, 2 and 3 only
B. 1, 3 and 4 only
C. 2 and 4 only
D. All four
Answer: A. 1, 2 and 3 only
Explanation: A geostationary satellite circles Earth in the equatorial plane with the same angular rate as Earth’s rotation, making it appear fixed over a longitude. Its altitude is about 35,786 km, not 22,236 km.
Q11. According to the question, Oceansat-2 helps in
1. atmospheric water-vapour assessment,
2. monsoon-related forecasting, and
3. coastal-water pollution monitoring.
Which are correct?
[UPSC CSE Prelims 2010, GS Paper I]
A. 1 and 2 only
B. 2 only
C. 1 and 3 only
D. 1, 2 and 3
Answer: D. 1, 2 and 3
Explanation: Oceansat-2 was launched in 2009 to study ocean colour and ocean-surface winds. Such observations help environmental and coastal-water monitoring and contribute to ocean–atmosphere analysis relevant to monsoon studies.
