UPSC Prelims 2025 · Question 61 of 100

UPSC Prelims 2025 question on Rare Earth Elements Electronics

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?

  1. Both Statement I and Statement II are correct and Statement II explains Statement I
  2. Both Statement I and Statement II are correct but Statement II does not explain Statement I
  3. Statement I is correct but Statement II is not correct
  4. Statement I is not correct but Statement II is correct
Show answer

Answer: A. Both Statement I and Statement II are correct and Statement II explains Statement I

Verdict

Both Statements I and II are correct and Statement II explains Statement I → Option (a).

Analysis

Statement II explains Statement I: The reason rare earth elements are used in flat-screen TVs and monitors (Statement I) is precisely because of their phosphorescent properties (Statement II) — they emit specific colors of light when energized, enabling high-quality displays.

Statement by statement

Statement I – CORRECT: Rare earth elements such as europium, terbium, and yttrium are used in the manufacture of flat-screen TVs and computer monitors, particularly in the color displays. Hence Statement I is correct.

Statement II – CORRECT: These rare earths have phosphorescent (or luminescent) properties, which means they emit light when excited by energy — this property is essential for producing vivid colors in display technologies. Hence Statement II is correct.

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