QUESTION 1
With reference to the NISAR mission, consider the following statements:
1. It is an Earth observation satellite jointly developed by NASA and ISRO.
2. The satellite will be launched on the PSLV-C61 and put in a sun-synchronous orbit.
3. The satellite will scan the entire globe every 30 days, providing a series of very detailed images of the Earth’s surface.
4. It will be the first satellite ever to observe the Earth in two frequencies.
How many of the statements given above are correct?
(a) Only one
(b) Only two
(c) Only three
(d) All four
Explanation
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— The much-awaited launch of NISAR — an earth observation satellite jointly developed by NASA and ISRO — is set to take place on July 30 at 5:40 pm from the country’s only spaceport in Sriharikota, Andhra Pradesh. Hence, statement 1 is correct.
— The satellite will be launched on the GSLV-F16 and be put in a 734 km sun synchronous orbit — an orbit in which the satellite reaches over a place at the same time each day. Hence, statement 2 is not correct.
— The satellite will scan the entire globe every 12 days, providing a series of very detailed images of the Earth’s surface. Hence, statement 3 is not correct.
— NISAR, which stands for NASA-ISRO Synthetic Aperture Radar, will provide an unprecedented view of the planet. Weighing 2,392 kg it will be the first satellite ever to observe the Earth in two frequencies — NASA’s L-band and ISRO’s S-band. “Each system’s signal is sensitive to different sizes of features on Earth’s surface, and each specializes in measuring different attributes, such as moisture content, surface roughness, and motion,” according to NASA. Hence, statement 4 is correct.
Therefore, option (b) is the correct answer.
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QUESTION 2
With reference to the chromosphere, consider the following statements:
1. It is a region sandwiched between the sun’s atmosphere (the million-degree corona) and the photosphere (the sun’s visible surface).
2. It is in the chromosphere where the solar flares, hot plasma jets, and powerful energy fluxes originate.
Which of the statements given above are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Explanation
— Solar physicists will make a new attempt to observe the chromosphere of the sun, which is the most dynamic region. NASA, along with a team of international solar physicists, will launch a sounding rocket experiment on July 18 from New Mexico.
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— Reddish in colour, the chromosphere is a region sandwiched between the sun’s atmosphere (the million-degree corona) and the photosphere (the sun’s visible surface). It is in the chromosphere where the solar flares, hot plasma jets, and powerful energy fluxes originate. The temperature variations recorded along this region can vary between 6000 degrees Celsius and over a million degrees Celsius. Hence, statements 1 and 2 are correct.
— The suborbital sounding rocket experiment will last under ten minutes. On board will be the Solar EruptioN Integral Field Spectrograph (SNIFS) – a solar-gazing spectrograph solar gazing spectrograph.
Therefore, option (c) is the correct answer.
QUESTION 3
Consider the following statements about MiG-21 fighter jets:
1. The Indian Air Force (IAF) is set to retire the remaining Russian-origin MiG-21 fleet in a ceremonial decommissioning on September 19 at the Chandigarh airbase.
2. There are five squadrons of the MiG-21 Bisons currently active.
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
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— The Indian Air Force (IAF) will ceremonially decommission the last Russian-origin MiG-21 fleet on September 19 at the Chandigarh airport. Hence, statement 1 is correct.
— Two squadrons of MiG-21 Bisons are currently operational. Hence, statement 2 is not correct.
— Since the aircraft’s introduction into the IAF in 1963, India has purchased around 700 MiG-21s in various variants, including the Type-77, Type-96, BIS, and Bison.
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— The retirement of the ageing MiG-21 fleet was originally scheduled for 2022, but was postponed due to a delay in the planned induction of additional fighter jets, including the indigenous Light Combat Aircraft Tejas, which will replace the MiG-21 squadrons.
Therefore, option (a) is the correct answer.
QUESTION 4
Which of the following viruses is also known as the ‘bleeding eye’ virus?
(a) Marburg virus
(b) Avian influenza
(c) Hepatitis B virus
(d) Hepatitis E virus
Explanation
— MVD, sometimes known as the “bleeding eye virus,” is one of the worst diseases capable of infecting humans. Case mortality rates in previous outbreaks ranged from 24% to 88%, depending on the virus type and case care. The first incidence in Rwanda this year was recorded in September.
— Marburg is a filovirus, just like Ebola. Both infections are clinically identical and, while rare, can generate high-fatality epidemics.
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— The first recognised MVD outbreak occurred in Marburg, Germany, in 1967. Following that, successive outbreaks have largely been recorded throughout Africa, most recently in Tanzania, Ghana, and now Rwanda.
— The World Health Organisation has listed MVD as one of the infections that pose the greatest hazard to public health and for which no suitable treatments or vaccinations exist.
Therefore, option (a) is the correct answer.
QUESTION 5
Consider the following:
1. Sulphur compounds
2. Helium gas
3. Argon gas
4. Pyroclastic debris
How many of the following are products of volcanic eruptions?
(a) Only one
(b) Only two
(c) Only three
(d) All four
Explanation
— Volcanoes can be on land and in the ocean. They are formed when material significantly hotter than its surroundings is erupted onto the surface of the Earth. The material could be liquid rock (known as “magma”, when it’s underground and “lava” when it breaks through the surface), ash, and/or gases.
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— Magma refers to the material found in the upper mantle. When it begins to move towards the crust or reaches the surface, it is known as “lava.”
— Lava flows, pyroclastic debris, volcanic bombs, ash and dust, as well as gases such as nitrogen compounds, sulphur compounds, and trace amounts of chlorine, hydrogen, and argon, all make their way to the ground.
— Helium is not a product of volcanic eruptions.
Therefore, option (c) is the correct answer.
QUESTION 6
Consider the following statements regarding Europa (one of the moon of Jupiter)
Statement I : Europa, one of Jupiter’s moons, is considered a strong candidate in the search for extraterrestrial life.
Statement II : The James Webb Space Telescope has detected carbon dioxide and crystalline water ice on Europa’s surface, indicating recent exposure of subsurface ocean material.
Which one of the following is correct?
(a) Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I
(b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I
(c) Statement-I is correct but Statement-II is incorrect
(d) Statement-I is incorrect but Statement-II is correct
Explanation
— Europa is widely regarded as one of the most promising places in our solar system to search for signs of life due to its subsurface ocean and signs of active geology. Hence, statement 1 is correct.
— James Webb Space Telescope observations confirmed the presence of crystalline water ice, carbon dioxide, and sodium chloride on Europa’s surface—especially in areas like Tara Regio—suggesting that material from the subsurface ocean is reaching the surface. Hence, statement 2 is correct.
— These findings support the idea that Europa may have the chemical and physical conditions necessary for life, making the Statement II a correct explanation for the Statement I.
Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I
Therefore, option (a) is the correct answer.
QUESTION 7
CoinDCX, recently in the news, is related to:
(a) A government digital payment initiative
(b) A space-tech startup collaborating with ISRO
(c) A cryptocurrency exchange that suffered a major hack
(d) A fintech app launched by RBI for rural banking
Explanation
— CoinDCX, Mumbai‑based crypto exchange, lost US $44.2 million from an internal operational wallet hack on July 19, 2025, discovered 17 hours later by blockchain investigator ZachXBT.
— It marks India’s second major crypto hack in one year, reinforcing the urgency for stronger cybersecurity protocols and regulatory standards in the digital asset domain.
Therefore, option (c) is the correct answer.
QUESTION 8
With reference to the NASA’s sounding-rocket mission, consider the following statements:
1. The instrument SNIFS is designed to study the Sun’s chromosphere, which lies between the photosphere and the corona.
2. SNIFS will capture 3D spectroscopic data, obtaining a full spectrum for each pixel in view.
3. The mission will measure the hydrogen Lyman‑α spectral line, a key diagnostic tool for chromospheric conditions.
4. SNIFS is an orbital satellite mission scheduled to operate for several years.
Which of the statements given above are correct?
(a) 1 and 2 only
(b) 1, 2 and 3 only
(c) 2, 3 and 4 only
(d) 1, 2, 3 and 4
Explanation
— SNIFS (Solar EruptioN Integral Field Spectrograph) will study the chromosphere, the dynamic layer sandwiched between the Sun’s visible surface (photosphere) and the outer corona. Hence, statement 1 is correct.
— It is the first ultraviolet integral field spectrograph to fly for solar study, providing 3D data sets where each pixel carries its own spectrum. Hence, statement 2 is correct.
— SNIFS targets the Lyman-α spectral line of hydrogen, the brightest line in the solar ultraviolet spectrum, crucial for diagnosing chromospheric temperature, velocity, and density. Hence, statement 3 is correct.
— SNIFS is a suborbital sounding‑rocket experiment, not a satellite mission; it will operate for under 10 minutes, not years. Hence, statement 4 is not correct.
Therefore, option (b) is the correct answer.
Previous Daily Subject-Wise-Quiz
Daily Subject-wise quiz — History, Culture, and Social Issues (Week 118)
Daily subject-wise quiz — Polity and Governance (Week 120)
Daily subject-wise quiz — Science and Technology (Week 119)
Daily subject-wise quiz — Economy (Week 119)
Daily subject-wise quiz — Environment and Geography (Week 119)
Daily subject-wise quiz – International Relations (Week 119)
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