UPSC Prelims 2025 PYQ on Rare Earth Elements in Display Technology
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?
✅ Correct Answer: (a) Both Statement I and Statement II are correct and Statement II explains Statement I
Explanation:
Rare earth elements (REEs) are a group of 17 chemically similar elements, including the 15 lanthanides plus scandium and yttrium.
They have unique magnetic, luminescent, and electrochemical properties, making them vital in electronics, renewable energy, and defense.
Statement I: Correct – Europium, terbium, and yttrium are used in phosphors for display technologies, producing vivid colors in flat-screen TVs and monitors.
Statement II: Correct – Certain REEs, like europium and terbium, have phosphorescent properties (emit light after being energized).
Statement II explains Statement I.The phosphorescent properties of rare earth elements are the reason they are used in manufacturing display screens. The ability of these elements to emit light upon excitation is fundamental to the functioning of phosphors in screens, thereby directly linking their phosphorescent nature to their application in display technologies.
