2019 GS Paper I, all questions
UPSC Prelims 2019 · GS Paper I
Question 26: Environment and Ecology
In the context of which one of the following are the terms ‘pyrolysis and plasma gasification’ mentioned?
aExtraction of rare earth elements
bNatural gas extraction technologies
cHydrogen fuel-based automobiles
dWaste-to-energy technologies
AnswerUPSC’s answer is (d).
Pyrolysis and plasma gasification are thermal waste-to-energy technologies. Pyrolysis heats waste in the absence of oxygen to give gas, oil and char; plasma gasification uses the intense heat of a plasma torch to turn waste into syngas and an inert slag, and the gas can be used for power. They are unrelated to extracting rare earth elements, producing natural gas or running hydrogen vehicles.
Why each option is right or wrong
- (a) Rare earths are extracted by mining and chemical processing, not by these methods.
- (b) Natural gas extraction uses drilling and fracking, not these terms.
- (c) Hydrogen vehicles use fuel cells or hydrogen engines.
- (d) Correct: both are waste-to-energy technologies.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2019, General Studies Paper I, Series A. The paper on upsc.gov.in.