[DAY 05] 60 DAY RAPID REVISION (RaRe) SERIES for UPSC Prelims 2024 – SCIENCE AND TECHNOLOGY, CURRENT AFFAIRS & CSAT TEST SERIES!

Solution (d)

Low Earth orbiting satellites experience orbital decay and have physical lifetimes determined almost entirely by their interaction with the atmosphere.

Every orbit — even gravitational orbits in General Relativity — will very, very slowly decay over time. It might take an exceptionally long time, some 10^150 years, but eventually, the Earth (and all the planets, after enough time) will have their orbits decay, and will spiral into the central mass of our Solar System. Hence, Statement 1 is incorrect.

Orbital decay is caused by one or more mechanisms which absorb energy from the orbital motion, such as fluid friction, gravitational anomalies, or electromagnetic effects. Hence, Statement 2 is incorrect

Solution (a)

Indian Remote Sensing Satellite (IRS), a sun synchronous satellite, is used for monitoring and management of natural resources (e.g. locating ground water resources, mineral exploration etc.) and Disaster Management Support. Under remote sensing, Hyperspectral imaging produces an image where each pixel has full spectral information with imaging narrow spectral bands over a contiguous spectral range.

The geostationary satellite is used for telecommunication, television broadcasting, and meteorological services.

Solution (c)

Cryogenic propulsion is centered on using cryogenic propellants stored at frigid temperatures. Cryogenic fuel has a greater mass flow rate than traditional fuels and produces more thrust and power. The fuel’s low-temperature liquid state is also environmentally cleaner than conventional fuels. Hence, Statement 1 and 2 are correct.

The semi-cryogenic stage envisioned for the NGLV consists of refined kerosene as fuel with liquid oxygen (LOX) as an oxidiser. Given the low atmospheric density in space, launch vehicles carry an oxidiser for ignition purposes. Hence, Statement 3 are correct.

Solution (c)

A scramjet engine is an improvement over the ramjet engine as it efficiently operates at hypersonic speeds and allows supersonic combustion. Thus it is known as Supersonic Combustion Ramjet, or Scramjet. Hence, Statement 1 is correct.

A dual mode ramjet (DMRJ) is a type of jet engine where a ramjet transforms into scramjet over Mach 4-8 range, which means it can efficiently operate both in subsonic and supersonic combustor modes. Hence, Statement 2 is correct.

Solution (a)

Uranus’ atmosphere consists primarily of hydrogen and helium, but it also contains “ices” such as water, ammonia and methane. These ices also make up the planet’s mantle, which surrounds a rocky inner core.

Neptune’s atmosphere is also mostly composed of hydrogen and helium. It also has similar ices. And again like Uranus, its interior is primarily ices and rock. Hence, Statement 1 & 2 is incorrect.

New research suggests that a layer of concentrated haze that exists on both planets is thicker on Uranus than a similar layer on Neptune and ‘whitens’ Uranus’s appearance more than Neptune’s. The model reveals that excess haze on Uranus builds up in the planet’s stagnant, sluggish atmosphere and makes it appear a lighter tone than Neptune. If there were no haze in the atmospheres of Neptune and Uranus, both would appear almost equally blue. Hence, Statement 3 is correct.

Solution (b)

Coronal holes can develop at any time and location on the Sun, but are more common and persistent during the years around solar minimum. Hence, Statement 1 is incorrect.

The more persistent coronal holes can sometimes last through several solar rotations (27-day periods). Coronal holes are most prevalent and stable at the solar north and south poles; but these polar holes can grow and expand to lower solar latitudes.  Hence, Statement 2 is correct.

It is also possible for coronal holes to develop in isolation from the polar holes; or for an extension of a polar hole to split off and become an isolated structure. Persistent coronal holes are long-lasting sources for high speed solar wind streams. Hence, Statement 3 is correct.

Solution (a)

All these terms come from theoretical physics branch, which investigates into state of matter and composition, origin, and extent of universe.

• Singularity and event horizons are related to Black Holes.
• Standard model of physics tries to explain universal phenomena.
• String theory is used in the context of quantum physics that is used to understand quantum phenomena.

Solution (d)

Astronomical distances are measures in light-years as the speed of light is constant.

A light-year is how astronomers measure distance in space. It’s defined by how far a beam of light travels in one year – a distance of six trillion miles.

Solution (a)

Solution (a)

Solution (c)

Solution (b)

IRNSS will provide two types of services, namely, Standard Positioning Service (SPS) which is provided to all the users and Restricted Service (RS), which is an encrypted service provided only to the authorised users. The IRNSS System is expected to provide a position accuracy of better than 20 m in the primary service area.

Some applications of IRNSS are:

• Terrestrial, Aerial and Marine Navigation
• Disaster Management
• Vehicle tracking and fleet management
• Integration with mobile phones
• Precise Timing
• Mapping and Geodetic data capture
• Terrestrial navigation aid for hikers and travellers
• Visual and voice navigation for drivers

Solution (b)

A particular type of active galaxy that emits more light at radio wavelengths than at visible wavelengths, also known as a radio-luminous galaxy or radio-loud galaxy. Radio galaxies are driven by non-thermal emissions. Radio telescopes show that some radio galaxies, called extended radio galaxies, have lobes of radio emission extending millions of light-years from their nuclei. Centaurus A is a nearby example of an extended radio galaxy.

Solution (a)

Solution (b)

Solution (c)

Solution (c)

Explanation:

Scientists define the beginning of interstellar space as the place where the Sun’s constant flow of material and magnetic field stop affecting its surroundings. This place is called the heliopause.

Interstellar space, the space between the stars– isn’t just empty space. There’s a lot of “stuff” out there, including hydrogen (70%) and helium (28%), formed in the Big Bang that set our universe into motion. The other 2% of “stuff” in interstellar space is heavier gases and dust, consisting of the other elements made inside stars and spewed into space by supernovae. The material in interstellar space is very spread out. It’s denser in some places than in others, but a typical density is about one atom per cubic centimeter. Still, even the most dense regions of interstellar space count as vacuum, compared with our earthly air.

Solution (d)

Plutoids are celestial bodies in orbit around the Sun at a semi major axis greater than that of Neptune that has sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighbourhood around their orbit. The International Astronomical Union has decided on the term plutoid as a name for dwarf planets like Pluto.

Solution (d)

Jupiter is the biggest planet in our solar system, and so it also has the strongest gravitational field among all the planets. The only celestial object whose gravitational pull exceeds that of Jupiter is the Sun. Jupiter is roughly 318 times the mass of Earth, yet its surface gravity is not 318 times as strong. Despite its immense mass, the force of gravity on the surface of Jupiter is only about twice and a half time as strong as Earth’s, or 24.8 meters per second square.

Solution (c)

Solution (c)

• Electronic Bank Realization Certificate (e-BRC) is proof of export issued by banks. Any firm applying for benefits under Foreign Trade Policy is required to furnish valid BRC as proof of realization of payment against exports made. Hence statement 1 is correct.
• A bank issues it as confirmation that the exporter has received payment from the buyer against the export of goods or services.
• It is an essential source of financial information and economic indicator.
• An exporter needs an eBRC to avail of the various export incentives (duty exemptions, subsidies, low-cost loans, etc.) offered by the government as part of its Foreign Trade Policy (FTP). Hence statement 2 is correct.

Solution (c)

• The Enforcement Directorate (ED) is a multi-disciplinary organization that works under the Department of Revenue, Ministry of Finance. Hence statement 1 is correct.
• It is a financial investigation agency mandated with the investigation of offences of money laundering and violations of foreign exchange laws.
• It enforces the provisions of the Foreign Exchange Management Act (FEMA) of 1999, the Conservation of Foreign Exchange and Prevention of Smuggling Activities Act (COFEPOSA) of 1974, the Fugitive Economic Offenders Act (FEOA) of 2018, and the Prevention of Money Laundering Act of (PMLA) 2002. Hence statement 2 is correct.
• Its officers are recruited from various investigation agencies like Indian Revenue Services (IRS), Indian Police Services (IPS), Excise Officers, Customs Officers, and Income Tax Officers. Hence statement 3 is correct.

Solution (b)

• Steel Slag Road Technology uses the waste produced during steel production to build robust and durable roads. Hence statement 1 is correct.
• It is an eco-friendly approach to managing industrial steel waste.
• It reduces the reliance on natural resources and is sustainable in the long term. It does not depend on natural ballast and aggregates and hence does not deplete natural resources. Hence statement 2 is incorrect.
• India is the world’s second-largest steel-producing country,generating around 19 million tonnes of steel slag as solid waste. It is projected to increase to a staggering 60 million tonnes by 2030, with each tonne of steel production resulting in about 200 kg of steel slag waste.
• It plays a very important role in fulfilling the mission of waste to wealth in India. Hence statement 3 is correct.

Solution (b)

• Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) is a regional organization that was established by the Bangkok Declaration on 6th June 1997. Hence statement 1 is correct.

• It has seven member countries of which five member countries – India, Bhutan, Bangladesh, Nepal, and Sri Lanka are from South Asia and two countries – Myanmar and Thailand are from Southeast Asia. Hence statement 2 is incorrect.
• Its secretariat is in Dhaka, Bangladesh. Hence statement 3 is correct.

Solution (b)

• Khashaba Dadasaheb Jadhav is an Indian wrestler who is nicknamed ‘Pocket Dynamo’. Hence statement 1 is correct.
• He was born in a village in Maharashtra.
• He was the first athlete from independent India to win an individual medal in the Olympics. Hence statement 2 is correct.
• He is known for winning a bronze medal at the 1952 Summer Olympics in Helsinki.
• He provided shelter to revolutionaries and circulated letters against the British during the Quit India Movement. Hence statement 3 is incorrect.

Solution (c)

• Gingee Venkataramana Temple was built in the 16th century by Muthyala Nayaka in Tail Nadu. Hence statement 1 is correct.
• Its entrance gateway depicts Ramayana scenes, Vishnu’s incarnations, and the Samudra Manthan. Hence statement 2 is correct.
• Its premises have a tank called Chettikulam which is fed by perennial springs and do not dry even in summer.
• It was built either in the 17th century by Rama Chetti or in the 18th century by Rama Shetty under the Maratha Kingdom. Hence statement 3 is correct.
• To the east of the temple is the Kalyanamahal, an architectural treasure built in the Vijayanagara style, is made up of a square court surrounded by rooms with verandahs on arches with stairways, in the middle of which is an 8-storey square tower with pyramidal roof.

Solution (d)

 Ramgarh Vishdhari Tiger Reserve is the fourth tiger reserve in Rajasthan, India. It comprises hilly dry deciduous forests consisting of Dhok, Khair, and Salar on Vindhyan formations. It plays a critical role in the movement of tigers. It has culturally significant monuments like Bhimlat. Hence option d is correct.

Solution (b)

• The Commission on Genetic Resources for Food and Agriculture (CGRFA) is the only permanent intergovernmental body focused on conserving all types of biodiversity for food and agriculture. Hence statement 1 is correct.
• It offers a unique platform for its members and other stakeholders to promote a world without hunger by fostering the use and development of the whole portfolio of biodiversity important to food security and rural poverty.
• Its membership is open to all members of the Food and Agriculture Organization (FAO). Hence statement 2 is incorrect.
• It consists of 179 Member States and the European Union.
• It meets regularly to address policies on genetic resources for food and agriculture.
• It focuses on the state of the world’s forest and plant genetic resources, access and benefit-sharing policies, and biotechnologies for the conservation, and sustainable use of genetic resources. Hence statement 3 is correct.

Solution (d)

 Gambusia affinis is a freshwater fish. It is also known as mosquito fish and has been a part of mosquito-control strategies for over a century in various parts of the world, including India. A single full-grown fish eats about 100 to 300 mosquito larvae per day. Hence option d is correct.

Solution (b)

• The Gomti River is a tributary of the Ganga River. Hence statement 1 is incorrect.
• It originates near Mainkot, from Gomat Taala Lake, Pilibhit. Hence statement 2 is correct.
• Lucknow, the capital of Uttar Pradesh is located on its banks. Hence statement 3 is correct.
• The River flows through Sitapur, Lucknow, Barabanki, Sultanpur, and Jaunpur before meeting the Ganga River.
• It meets the Ganges River at Kaithi, Ghazipur district.

Solution (b)

Making all possible combinations – 123, 132, 213, 231, 312,  321 – we get 6 combinations

The total number of n-digit numbers are given by n! = 3! =6.

Hence, Option(b) is the right answer.

Solution (b)

6, 15, 49, 201, 1011, X

6

6 * 2 + 3 = 15

15 * 3 + 4= 49

49 * 4 + 5= 201

201 * 5 + 6= 1011

1011 *6 + 7 = 6073

Solution (c)

Let the two numbers be a and b respectively. As we know that the sum of the two numbers is 109 So, a + b = 109 ……………(1)

Also, one fifth of a number is five more than one seventh of another number So, a/5 = b/7 + 5. ……………(2)

As second number is a perfect square and also divisible by 7. So, b should be equal to 49.

And a = 109 – 49 = 60.

Now, we examine all the given options: Option (a): False ->Difference of the two numbers is 11. (Odd) Option (b): False ->HCF (60, 49) =1. Option (c): True ->Difference of two numbers is 11 (prime). Hence, option (c) is the correct answer.

Solution (c)

The number of zeros at the end of (5!)5! =120

(∵ 5! = 120 and thus 120^120 will give 120 zeros)

Number of zeros at the end of (10!)^10!, (50!)^50!and (100!)^100! will be greater than 120.

Now since the number of zeros at the end of the whole expression will depend on the number which has least number of zeros at the end of the number among the other given numbers.

So, the number of zeros at the end of the given expression is 120.

Solution (c)

Of the two-consecutive integer one will always be odd and one will be even

(3, 4) → 3^2 ⇒ 9 ⇒ 8n + 1 (n = 1)

(4, 5) → 5^2 ⇒ 25 ⇒ 8n + 1 (n = 3)

(6, 7) → 7^2 ⇒ 49 ⇒ 8n + 1 (n = 6)

(8, 9) → 9^2 ⇒ 81 ⇒ 8n + 1 (n = 10)

(10, 11) → 11^2 ⇒ 121 ⇒ 8n + 1 (n = 15)

∴Both the statements given here are correct.