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Prelims 2021 paper

UPSC CSE Prelims 2021 · GS Paper I · Question 17 · Pollution & waste

ताम्र प्रगलन संयंत्रों के बारे में चिन्ता का कारण क्या है?

UPSC Civil Services (Preliminary) Examination 2021, General Studies Paper I, Question 17 — Pollution & waste.

Prelims 2021 · Q17

Pollution & waste X-Ray · Core #13 Medium

ताम्र प्रगलन संयंत्रों के बारे में चिन्ता का कारण क्या है?

  1. 1.वे पर्यावरण में कार्बन मोनोक्साइड को घातक मात्राओं में निर्मुक्त कर सकते हैं।
  2. 2.ताम्रमल (कॉपर स्लैग) पर्यावरण में कुछ भारी धातुओं के निक्षालन (लीचिंग) का कारण बन सकता है।
  3. 3.वे सल्फर डाइऑक्साइड को एक प्रदूषक के रूप में निर्मुक्त कर सकते हैं।

नीचे दिए गए कूट का प्रयोग कर सही उत्तर चुनिए।

Read this question in English

Why is there a concern about copper smelting plants?

1. They may release lethal quantities of carbon monoxide into environment.

2. The copper slag can cause the leaching of some heavy metals into environment.

3. They may release sulphur dioxide as a pollutant.

Select the correct answer using the code given below.

(a) 1 and 2 only · (b) 2 and 3 only · (c) 1 and 3 only · (d) 1, 2 and 3

उत्तर और व्याख्या · explanation in English

Answer: (b) केवल 2 और 3

Most copper comes from sulphide ores, so smelting them drives off sulphur dioxide, a major air pollutant. The glassy waste left behind, copper slag, still carries heavy metals that can contaminate soil and water if stored carelessly. Releasing lethal amounts of carbon monoxide is not the recognised hazard of these plants.

  • ✗ 1. The air-pollution concern linked to smelting ores that contain sulphur is sulphur dioxide, not lethal quantities of carbon monoxide; UPSC's key treats statement 1 as wrong.
  • ✓ 2. Copper slag (Ferro sand) contains arsenic, cadmium, chromium, cobalt, nickel, lead and zinc, and the CPCB guideline asks smelters to store slag on an impermeable base with a garland drain to prevent soil and groundwater contamination.
  • ✓ 3. Roasting and smelting sulphide ores releases sulphur dioxide; the WHO lists the smelting of sulphur-bearing ores as a main source of SO2.

Remember · Copper smelters: sulphur dioxide (from sulphide ores) in the air, and heavy-metal leaching from slag heaps.

Sources

Question and answer: UPSC's official GS Paper I (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). ·

Cite this question: UPSC CSE Prelims 2021, Q17 — minimalistias.com/pyqs/prelims/2021/q17

In the UPSC syllabus: Pollution & waste › Air pollution & air-quality standards See it and tick it covered →

Timed · 30 minutes Take Environment & ecology · Set 5 as a test This question is in it — with UPSC's marking and an instant score. Start the set Or the whole 2021 paper →

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