UPSC CSE 2025 · PYQ · Mineral Resources / Rare Earth Elements · medium
Consider the following statements:
Statement I: Some rare earth elements are used in the manufacture of flat television screens and computer monitors.
Statement II: Some rare earth elements have phosphorescent properties.
Which one of the following is correct in respect of the above statements?
A.Both Statement I and Statement II are correct and Statement II explains Statement I✓ Correct
B.Both Statement I and Statement II are correct but Statement II does not explain Statement I
C.Statement I is correct but Statement II is not correct
D.Statement I is not correct but Statement II is correct
Explanation
Both statements are correct, and Statement II explains Statement I. Rare earth elements such as europium (red phosphor), terbium (green phosphor), and yttrium are used in the manufacture of flat television screens, computer monitors, and LED displays because of their phosphorescent properties — they emit visible light when excited by electrons or UV radiation. This phosphorescence is precisely what makes them indispensable for producing the colored pixels in display screens, so Statement II directly explains Statement I.
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