UPSC Prelims 2016 · GS Paper I
Question 87: Science and Technology
With reference to ‘Astrosat’, the astronomical observatory launched by India, which of the following statements is/are correct?
- 1.Other than USA and Russia, India is the only country to have launched a similar observatory into space.
- 2.Astrosat is a 2000 kg satellite placed in an orbit at 1650 km above the surface of the Earth.
Select the correct answer using the code given below.
AnswerUPSC’s answer is (d).
Astrosat, launched in September 2015, is India's first dedicated multi-wavelength space observatory. It weighs about 1,500 kg and was placed in a low Earth orbit at about 650 km, not 1,650 km. Statement 1 also fails: Japan and the European Space Agency have launched space X-ray observatories too, so India is not the only country besides the US and Russia.
- 1. Japan and ESA have also launched space observatories.
- 2. Astrosat weighs about 1,500 kg and orbits at about 650 km.
How you could have got this
- If you were sure statement 1 is not correct, (a) and (c) go: each of them includes 1.
What you needed to know: Japan and ESA have also launched space observatories.
The red flag in statement 1 is “only”. In UPSC’s papers, statements with “only” were true 27% of the time (82 statements). A hint, not a rule.
- Then, if you were sure statement 2 is not correct, (b) goes: it includes 2.
What you needed to know: Astrosat weighs about 1,500 kg and orbits at about 650 km.
Only (d) is left. This one needs every statement.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Statement 1 is wrong: other agencies have launched space observatories.
- (b) Statement 2 is wrong: the orbit is about 650 km.
- (c) Both statements are wrong, so 'both' fails.
- (d) Right: neither statement is correct.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2016, General Studies Paper I, Series A. The paper on upsc.gov.in.