Science and Technology MCQ Set 18
Showing question 86 to 90 of total 301 MCQs
MCQ Set: 18
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Question No: 86
Which region of Mars has a densely packed river deposit indicating this planet had water 3.5 billion years ago?
- Aeolis Dorsa
- Tharsis
- Olympus Mons
- Hellas
Answer and Explanation
Answer: A
Explanation
Mars had a surface environment that supported liquid water about 3.5 billion years ago, according to a study of river deposits spread across the red planet.
A region of Mars named Aeolis Dorsa contains some of the most spectacular and densely packed river deposits seen on the planet, researchers said.
These deposits are observable with satellite images because they have undergone a process called “topographic inversion,” where the deposits filling once topographically low river channels have been exhumed in such a way that they now exist as ridges at the surface of the planet, they said.
With the use of high-resolution images and topographic data from cameras on orbiting satellites, researchers identified fluvial deposit stacking patterns and changes in sedimentation styles controlled by a migratory coastline.
They also developed a method to measure river paleo-transport direction for a subset of these ridges.
Together, these measurements demonstrate that the studied river deposits once filled incised valleys. On Earth, incised valleys are commonly cut and filled during falling and rising eustatic sea level, respectively.
Cardenas and colleagues conclude that similar falling and rising water levels in a large water body forced the formation of the paleo-valleys in their study area.
Cross-cutting relationships are observed at the valley-scale, indicating multiple episodes of water level fall and rise, each well over 50 metres, a similar scale to eustatic sea level changes on Earth, researchers said.
The conclusion that such large water level fluctuations and coastline movements were recorded by these river deposits suggests some long-term stability in the controlling, downstream water body, which would not be expected from catastrophic hydrologic events.
Question No: 87
Which Indian astrophysicist and Nobel laureate predicted rapidly rotating stars emit polarised light?
- Subrahmanyan Chandrasekhar
- CV Raman
- Ramanujan
- Amartya Sen
Answer and Explanation
Answer: A
Explanation
Over 70 years after Indian astrophysicist and Nobel laureate Subrahmanyan Chandrasekhar predicted that rapidly rotating stars would emit polarised light, scientists in Australia have observed the phenomenon for the first time.
Researchers used a highly sensitive piece of equipment to detect the polarised light from Regulus, one of the brightest stars in the night sky.
The equipment provided unprecedented insights into the star, which is in the constellation Leo, allowing the scientists to determine its rate of spinning and the orientation in space of the star’s spin axis.
Regulus is rotating so quickly it is close to flying apart, with a spin rate of 96.5 per cent of the angular velocity for break-up.
It is spinning at approximately 320 kilometres per second - equivalent to travelling from Sydney to Canberra in less than a second.
Chandrashekar's Prediction: Know More
In 1946, Chandrasekhar had predicted the emission of polarised light from the edges of stars, prompting the development of sensitive instruments called stellar polarimeters to try to detect this effect.
Optical polarisation is a measure of the orientation of the oscillations of a light beam to its direction of travel.
In 1968, other researchers built on Chandrasekhar’s work to predict that the distorted, or squashed, shape of a rapidly rotating star would lead to the emission of polarised light, but its detection has eluded astronomers until now.
The instrument built, the High Precision Polarimetric Instrument (HIPPI) is the world’s most sensitive astronomical polarimeter.
Its high precision has allowed scientists to detect polarised light from a rapidly spinning star for the first time
It has previously been extremely difficult to measure these properties of rapidly rotating stars, researchers said.
Yet the information is crucial for understanding the life cycles of most of the hottest and largest stars in the galaxies, which are the ones that produce the heaviest elements, such as iron and nickel, in interstellar space.
Regulus: Know More
Regulus is about 79 light years away.
Regulus, also designated Alpha Leonis, is the brightest star in the constellation of Leo and one of the brightest stars in the night sky, lying approximately 79 light years from the Sun.
Constellation: Leo
B - V color index: –0.11/+0.86
U - B color index: –0.36/+0.51
Apparent magnitude (V): 1.40/8.13/13.50
Absolute magnitude (MV): –0.52/6.3/11.6
Age: ? Polarised light emitted by 1 Gyr
During the total solar eclipse in the US in August, Regulus was just one degree away from the Sun.
It was, to many people, the only star visible during the eclipse.
Question No: 88
Which Google payment app was launched on 18th Sept 2017?
- Zet
- Ezt
- Tez
- Tze
Answer and Explanation
Answer: D
Explanation
On 18th Sept 2017, Finance Minister Arun Jaitley launched Google’s payment app - ‘Tez’.
Tez by Google is perhaps the simplest form of monetary transactions.
Tez by Google and other ecosystems will make a major change in the digital payments landscape in India.
The tech giant claimed that Tez will enable money transfer directly from the bank accounts of customers, without them having to share their ‘personal information’.
The app will function on both Android and iOS platforms.
Google also said that the app will ‘understand’ eight Indian languages and will work with 55 banks
Tez (which means “Fast” in Hindi is Google’s play to replace cash transactions and become a more central part of how people pay for things, using their mobile to do so.
But it’s also a chance for the company to push out some new technologies - like audio QR (AQR), which lets users transfer money by letting their phones speak to each other with sounds - to see how it can make that process more frictionless, and therefore more attractive to use than cash itself.
Tez will see Google linking up with several major banks in the country by way of UPI (Unified Payments Interface) - a payment standard and system backed by the government in its push to bring more integrated banking services into a very fragmented market.
There will also be phones coming to the market from Lava, Micromax, Nokia and Panasonic with Tez preloaded, the company said.
Google has confirmed to me that payments made and taken using UPI are free for consumers and small merchants
To be clear, Tez is not a mobile “wallet” in the same way as PayTM offers a mobile wallet, where money is stored in the app and needs to be topped up to be used;
It’s more like Apple’s Wallet or other mobile wallets in the west: a place that links up your phone with your bank accounts to let you use your phone as a way to deduct payments from those accounts.
Supported banks include Axis, HDFC Bank, ICICI and State Bank of India and others that support UPI.
Online payment partners include large food chains like Dominos, transport services like RedBus, and Jet Airways
The app has support for English, Hindi, Bengali, Gujarati, Kannada, Marathi, Tamil, and Telugu.
For money transfers, there is a limit of ?1,00,000 in one day across all UPI apps, and 20 transfers in one day.
AQR and Tez: Know More
Google says that AQR - the sound-based format for transferring money securely between devices - is its own proprietary technology.
This appears to be the first time that Google has used it for payments, although it has used ultrasonic sound for transferring information between devices before
For example, the tech has been used in Chromecast to connect devices since 2014. Other startups that have used audio-based “codes” to transfer payments and other data before include Lisnr, and Chirp.
While AQR might seem like a neat technical twist, there are some practical reasons behind why Google might opt for this in Tez.
For starters, it obviates the need for NFC in the device, and in the payment devices of merchants or whoever else a person is planning to transact with.
The other thing is that it makes any kind of contactless transaction with the device fairly flexible and easy.
Services like Airdrop on iPhones require Bluetooth and if you’ve used it before isn’t that seamless and foolproof to turn on (even though it works like a charm when it does). QR codes, meanwhile, require you to turn on the camera on your device and physically align it with a code on another screen, a potentially fiddly and difficult process.
Using audio taps into some of the most basic features on even the most basic phones, a speaker and a microphone.
Google has also trademarked the name in other Asian countries like Indonesia and the Philippines, so there seems to be a wider strategy to expand this to other regions.
India, the second-most populated country in Asia after China, is a ripe market for mobile payment services, with a rapidly expanding middle class with more disposable income and a wider population that is very tech-focussed, with an estimated 300 million smartphones in use today.
Digital payments are expected to reach a volume of $500 billion annually by 2020, according to a report from BCG and Google.
Question No: 89
Giant triton
- Giant triton
- Pacific triton sea snail
- Both a and b
- None of above
Answer and Explanation
Answer: C
Explanation
A giant starfish-eating snail could be unleashed to help save the Great Barrier Reef, officials said with a trial under way to breed thousands of the rare species.
Predatory crown-of-thorns starfish, which munch coral, are naturally-occurring but have proliferated due to pollution and run-off at the struggling World Heritage-listed ecosystem.
Their impact has been profound with a major study of the 2,300-km long reef’s health in 2012 showing coral cover halved over the past 27 years, with 42% of the damage attributed to the pest.
Now, Australian Institute of Marine Science (AIMS) research has shown they avoid areas where the Pacific triton sea snail - also known as the giant triton - is present.
The snails, which can grow to half a metre, have a well developed sense of smell and can hunt their prey by scent alone.
Research showed they were particularly fond of crown-of-thorns, but only eat a few each week, and with the snail almost hunted to extinction for their shells, there are not many left.
This led the government to announce funding to research breeding them.
The possibilities the triton breeding project opens up are exciting.
If successful, this research will allow scientists to closely look at the impact of giant tritons on crown-of-thorns behaviour and test their potential as a management tool to help reduce coral lost to outbreaks.
Giant tritons held at AIMS have laid numerous egg capsules. But they are so rare, almost nothing is known about their life cycle.
Question No: 90
Which planet was downgraded to dwarf planet status?
- Pluto
- Mars
- Earth
- Venus
Answer and Explanation
Answer: A
Explanation
'Planet 9' - an unseen planet on the edge of our solar system - probably formed closer to home around the Sun than previously thought, astronomers say.
Researchers in the UK found that Planet 9 is unlikely to have been captured from another planetary system, as has previously been suggested.
The outskirts of the solar system have always been something of an enigma, with astronomers in the late 19th and early 20th centuries searching for a giant planet that was not there, and the subsequent discovery of Pluto in 1930.
Pluto was downgraded in status to a 'dwarf planet' because astronomers discovered many other small objects so-called Edgeworth-Kuiper Belt objects at similar distances from the Sun.
Last year, astronomers working in the US postulated the presence of 'Planet 9' to explain the strange orbital properties of some Edgeworth-Kuiper Belt objects.
However, while it is not possible to directly observe Planet 9, it has not stopped theorists from trying to work out how it got there.
Planet 9: Know More
Planet 9 is at least ten times bigger than Earth, making it unlikely that it formed at such a large distance from the Sun.
Instead, it has been suggested it either moved there from the inner regions of the Solar System, or it could have been captured when the Sun was still in its birth star cluster.
Researchers simulated the Sun's stellar nursery where interactions are common and found that even in conditions optimised to capture free-floating planets, only five-to-10 out of 10,000 planets are captured onto an orbit like Planet 9's.