Set A - UPSC Prelims 2025 Solutions

QQuestion

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?

OOptions

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

✓Correct Answer

A) Both Statement I and Statement II are correct and Statement II explains Statement I

DDalvoy Solutions

Statement I: Correct. Rare earth elements are indeed used in manufacturing flat television screens and computer monitors for various components including phosphors, magnets, and electronic circuits.

Statement II: Correct and explains Statement I. Some rare earth elements, particularly europium and terbium, have phosphorescent properties that make them essential for creating the phosphors used in display screens. These phosphors convert electrical energy into visible light in specific colors, enabling the display functionality.

The phosphorescent properties of rare earth elements directly explain their application in display technology, making them crucial for modern electronic displays.

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SUPSC Prelims Strategy and Tips

For rare earth element questions, connect their unique properties (magnetic, phosphorescent, catalytic) to their specific technological applications in modern electronics and clean energy systems.

SUPSC Prelims 2025 Syllabus Analysis

Science & Technology - Materials science and electronic applications

AUPSC Prelims 2025 Question Analysis

Medium difficulty - requires understanding of rare earth element properties and applications

Question 81

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