निम्नलिखित कथनों पर विचार कीजिए :
- कथन I: कुछ दुर्लभ मृदा तत्त्व, सपाट टेलीविजन स्क्रीन और कम्प्यूटर मॉनीटर के निर्माण में प्रयुक्त होते हैं।
- कथन II: कुछ दुर्लभ मृदा तत्त्वों में स्फुरदीप्त गुणधर्म होते हैं।
उपर्युक्त कथनों के संदर्भ में, निम्नलिखित में से कौन-सा एक सही है?
Read this question in English
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
उत्तर और व्याख्या · explanation in English
Answer: (a) कथन I और कथन II दोनों सही हैं तथा कथन II, कथन I की व्याख्या करता है
Both statements are correct. Rare earth compounds such as europium and yttrium oxides act as phosphors, the light-emitting coatings that give colour in television and computer screens, so their luminescent property is exactly why they are used in displays.
- ✓ Statement-I IREL (India) Limited, a Department of Atomic Energy undertaking, lists television screens, computers and monitor displays among rare-earth uses; europium and yttrium oxides produce the red colour in television screens.
- ✓ Statement-II Rare earths have luminescent properties, and several (europium, terbium) are used as phosphors. That is why they light up screens, so this statement explains Statement-I.
Remember · Europium and yttrium oxides are rare-earth phosphors: their luminescence gives red (and, with europium, blue) colour in TV and phone screens.
Sources
- FAQ on rare earths, IREL (India) Limited (Department of Atomic Energy) ↗ · reference work “Europium and Yttrium (oxides) produce the red colors in television screens and smart phone screens. … The REEs have unique catalytic, metallurgical, nuclear, electrical, magnetic and luminescent properties.”
Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·