Q. 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
(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
UPSC Prelims 2025 GS Paper's Solution
Explanation :
Statement I: Some rare earth elements are used in the manufacture of flat television screens and computer monitors.
- Correct. Rare earth elements like europium, yttrium, and terbium are used to create red, green, and blue phosphors for vibrant colors in these displays.
Statement II: Some rare earth elements have phosphorescent properties.
- Correct. Many rare earth elements exhibit phosphorescence and fluorescence. Europium and terbium are known for their phosphorescent properties.
Relationship:
- The phosphorescent properties of rare earth elements explain their use in flat-screen TVs and monitors, as they produce the luminescent phosphors essential for vibrant colors.
Conclusion:
- Both statements are correct, and Statement II explains Statement I.
