The Giant Metrewave Radio Telescope consists of
- A.a single parabolic antenna
- B.multiple parabolic antennas
- C.multiple circular antennas
- D.a combination of circular and parabolic antennas
Correct answer
Explanation
The correct answer is B, multiple parabolic antennas. The Giant Metrewave Radio Telescope (GMRT) is an array of 30 fully steerable parabolic dish antennas, each 45 metres across. It stands at Khodad near Narayangaon, about 80 km north of Pune in Maharashtra, and is run by the National Centre for Radio Astrophysics (NCRA) of the Tata Institute of Fundamental Research. Its dishes are spread over about 25 km and work together by interferometry, so the array behaves like one very large telescope. It observes the sky at metre wavelengths, studying pulsars, distant galaxies and the neutral hydrogen of the early universe. Option A is wrong because a single dish could not give the resolution that 30 linked dishes provide. Option C is wrong because the dishes are parabolic reflectors, not flat circular antennas. Option D is wrong because all 30 antennas are of the same parabolic design. Exam tip: GMRT = 30 dishes of 45 m, Khodad near Pune, run by NCRA-TIFR, metre-wave radio astronomy.
Practice Questions
View allIn India, it is legally mandatory for which of the following to report on cyber security incidents? 1. Service providers 2. Data centres 3. Body corporate Select the correct answer using the code given below:
- A.1 only
- B.1 and 2 only
- C.3 only
- D.1, 2 and 3
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All three are legally bound to report cyber security incidents to CERT-In, the Indian Computer Emergency Response Team. CERT-In works under Section 70B of the Information Technology Act, 2000 as the national agency for incident response.
Read the full explanation →Consider the following statements : The Mangalyaan launched by ISRO 1. is also called the Mars Orbiter Mission 2. made India the second country to have a spacecraft orbit the Mars after USA 3. made India the only country to be successful in making its spacecraft orbit the Mars in its very first attempt Which of the statements given above is/are correct?
- A.1 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
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Mangalyaan is the popular name of ISRO's Mars Orbiter Mission, and India reached Mars orbit on its first attempt, but it was not the second country to do so.
Read the full explanation →What is the application of Somatic Cell Nuclear Transfer Technology ?
- A.Production of biolarvicides
- B.Manufacture of biodegradable plastics
- C.Reproductive cloning of animals
- D.Production of organisms free of diseases
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Somatic cell nuclear transfer, or SCNT, is the technique used to clone an animal. Scientists take an egg cell and remove its nucleus.
Read the full explanation →Organic Light Emitting Diodes (OLEDs) are used to create digital display in many devices. What are the advantages of OLED displays over Liquid Crystal displays ? 1. OLED displays can be fabricated on flexible plastic substrates. 2. Roll-up displays embedded in clothing can be made using OLEDs. 3. Transparent displays are possible using OLEDs. Select the correct answer using the code given below:
- A.1 and 3 only
- B.2 only
- C.1, 2 and 3
- D.None of the above statements is correct
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All three are real advantages of OLEDs, and they follow from the fact that each OLED pixel makes its own light.
Read the full explanation →India is an important member of the 'International Thermonuclear Experimental Reactor'. If this experiment succeeds, what is the immediate advantage for India?
- A.It can use thorium in place of uranium for power generation
- B.It can attain a global role in satellite navigation
- C.It can drastically improve the efficiency of its fission reactors in power generation
- D.It can build fusion reactors for power generation
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ITER is an experiment to prove that nuclear fusion can work as a large-scale energy source, and every member shares its technology.
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