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UPSC Combined Geo-Scientist

Chemist

  • 3 descriptive papers
  • 200 marks each
  • 3 h per paper

Mains Paper III covers analytical and organic chemistry.

UPSC Combined Geo-Scientist, Mains · 2025 · Mains Paper III

Q5(a). Energy dispersive X-ray fluorescence: theory and instrument

Question

Briefly outline the basic theory and instrumentation of energy dispersive X-ray fluorescence spectroscopy.

Model answer

The free solution for 2025 answers questions 1, 2, 4, 6, 7 and 9, the ones picked in its time plan. Question 5 is answered in full in the Geo-Scientist Chemistry Paper III, 2021 to 2025 book, with every part of every paper.

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Cover of UPSC Combined Geo-Scientist (Main) Chemistry Paper III: Model Answers 2021 to 2025
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UPSC Combined Geo-Scientist (Main) Chemistry Paper III: Model Answers 2021 to 2025

  • All ten questions of each paper, with the question printed above its answer
  • Instruments drawn as labelled diagrams, numericals worked with units
  • Topic-wise weightage and a topic-wise index
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Topic notes: X-ray methods and ICP (Bragg's law, powder XRD, XRF, ICP torch, ICP-MS interferences), with every Civil Services, IFoS and Geo-Scientist PYQ →

CoversEDXRFX-ray fluorescenceenergy dispersive detectorSi(Li) detectorXRF instrumentation

All parts of Question 5