2017 GS Paper I, all questions

UPSC Prelims 2017 · GS Paper I

Question 87: Science and Technology

What is the purpose of ‘evolved Laser Interferometer Space Antenna (eLISA)’ project ?

aTo detect neutrinos
bTo detect gravitational waves
cTo detect the effectiveness of missile defence system
dTo study the effect of solar flares on our communication systems

AnswerUPSC’s answer is (b).

The evolved Laser Interferometer Space Antenna was a proposed European Space Agency mission to detect gravitational waves, the ripples in space-time produced by massive objects such as merging black holes. Three spacecraft flying in formation millions of kilometres apart would use laser beams to measure tiny changes in their separation as a wave passes. It has nothing to do with neutrinos, missile defence or solar flares. Remember: LISA = gravitational waves, LIGO is its ground-based counterpart.

Why each option is right or wrong
  • (a) Wrong: neutrinos are detected by different observatories.
  • (b) Right: eLISA is meant to detect gravitational waves from space.
  • (c) Wrong: it has no role in testing missile defence.
  • (d) Wrong: solar flares are studied by solar observatories, not eLISA.

Worth knowing: The project is now called LISA; the question is answered as it stood in 2017.

Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.

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Source: UPSC, Civil Services (Preliminary) Examination 2017, General Studies Paper I, Series A. The paper on upsc.gov.in.