UPSC Combined Geo-Scientist, Mains · 2023 · Mains Paper III
Q2(d). No K lines of silver at a tube voltage of 24 kV
Question
In XRF instrument, when tube voltage is set at 24 kV, K X-ray lines of Ag are not observed. Explain the observation. Given: K absorption edge of Ag = 0.485 Å; K emission line of Ag = 0.497 Å.
Model answer
The free solution for 2023 answers questions 1, 4, 5, 6, 7 and 10, the ones picked in its time plan. Question 2 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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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
CoversXRFabsorption edgeDuane–Hunt limittube voltagesilver K lines
All parts of Question 2
- 2(a) Type of analysis: 1 µL sample, analyte at ppb to ppm5 marks
- 2(b) Number of theoretical plates and HETP from a Gaussian peak10 marks
- 2(c) CaCO₃ and MgCO₃ in a dolomite sample from its thermogram10 marks
- 2(d) No K lines of silver at a tube voltage of 24 kV5 marks