Q10. Heating ores in the absence of oxygen is called
[RRB Group D, 6 December 2018, Shift 1]
(A) Extraction
(B) Calcination
(C) Roasting
(D) Corrosion
𝐀𝐧𝐬𝐰𝐞𝐫: (B) Calcination
Explanation: Calcination involves strong heating with little or no supply of air, commonly converting carbonate ores into oxides while driving off carbon dioxide or water. Roasting, by contrast, heats ores in the presence of oxygen, especially sulphide ores.
Q9. Which metal is used for making filaments of electric bulbs?
[RRB Group D, 28 September 2018, Shift 2]
(A) Iron
(B) Tungsten
(C) Silver
(D) Nickel
𝐀𝐧𝐬𝐰𝐞𝐫: (B) Tungsten
Explanation: Tungsten has an exceptionally high melting point, making it suitable for incandescent lamp filaments that operate at very high temperatures. Although efficient modern lamps use other technologies, tungsten remains the classic incandescent-filament metal.
Q8. Which of the following is an ore of iron?
[SSC CGL, 12 August 2017, Shift 2]
(A) Dolomite
(B) Epsom salt
(C) Siderite
(D) Galena
𝐀𝐧𝐬𝐰𝐞𝐫: (C) Siderite
Explanation: Siderite is iron(II) carbonate, FeCO₃, and can be used as an iron ore. Galena is lead sulphide, dolomite is calcium magnesium carbonate, and Epsom salt is magnesium sulphate heptahydrate.
Q7. Which mineral is responsible for the red colour in bricks?
[SSC JE (Civil Engineering), 3 March 2017, Morning]
(A) Iron oxide
(B) Lime
(C) Magnesia
(D) Silica
𝐀𝐧𝐬𝐰𝐞𝐫: (A) Iron oxide
Explanation: Iron oxides in clay are responsible for the typical reddish colour of fired bricks. During firing, iron-bearing compounds transform into coloured oxides. Silica contributes structure and stability, while alumina provides plasticity to mouldable brick earth.
Q6. Of the following types of iron ore, which has the largest reserves in India?
[CGPSC Civil Services (General Studies) Paper I, 2017]
(A) Hematite
(B) Magnetite
(C) Siderite
(D) Limonite
(E) None of these
𝐀𝐧𝐬𝐰𝐞𝐫: (A) Hematite
Explanation: The examination identifies hematite as the leading category of iron-ore reserves in India. Its chemical formula is Fe₂O₃, and prominent deposits occur in Odisha, Jharkhand and Chhattisgarh. Magnetite is another important iron ore.
Q5. Which metal is present in chlorophyll?
[WBCS Preliminary Examination, 2016]
(A) Iron
(B) Zinc
(C) Aluminium
(D) Magnesium
𝐀𝐧𝐬𝐰𝐞𝐫: (D) Magnesium
Explanation: A magnesium ion occupies the centre of the chlorophyll molecular structure. Chlorophyll absorbs light for photosynthesis in plants and other photosynthetic organisms. Iron is important in many biological processes, but it is not chlorophyll’s central metal.
Q4. Which among the following is the largest mechanized mine in India?
[UPPSC Civil Services Preliminary Examination, 10 May 2015]
(A) Ratnagiri mine
(B) Jaipur mine
(C) Sundergarh mine
(D) Bailadila mine
𝐀𝐧𝐬𝐰𝐞𝐫: (D) Bailadila mine
Explanation: The Bailadila iron-ore mining complex in Chhattisgarh includes large mechanized operations developed by NMDC. The deposits contain high-grade hematite. Mining and ore-handling systems there supply iron ore to domestic industry and export markets.
Q3. Which one of the following minerals is not found in Uttar Pradesh?
[UPPSC Civil Services (General Studies) Paper I, 2014]
(A) Limestone
(B) Mica
(C) Bauxite
(D) Gypsum
𝐀𝐧𝐬𝐰𝐞𝐫: (B) Mica
Explanation: The question’s state-mineral inventory identifies mica as the exception. Uttar Pradesh has occurrences of limestone and other industrial minerals, while major mica-bearing zones are associated with states such as Andhra Pradesh, Rajasthan and Jharkhand.
Q2. Which is the correct decreasing sequence in value (rupees) of minerals produced in India during 2002–03?
[UPSC CSE Preliminary Examination (General Studies), 2004]
(A) Metallic minerals – Fuel minerals – Non-metallic minerals
(B) Fuel minerals – Metallic minerals – Non-metallic minerals
(C) Metallic minerals – Non-metallic minerals – Fuel minerals
(D) Fuel minerals – Non-metallic minerals – Metallic minerals
𝐀𝐧𝐬𝐰𝐞𝐫: (B) Fuel minerals – Metallic minerals – Non-metallic minerals
Explanation: The 2002–03 production-value ordering placed fuel minerals first, followed by metallic minerals and then non-metallic minerals. The question concerns the value of mineral output in that historical year, not present-day mining quantities or prices.
Q1. Match oxidation numbers
A. +2;
B. +3;
C. +4;
D. +6
with:
1. Mn in MnO₂;
2. S in H₂S₂O₇;
3. Ca in CaO₂;
4. Al in NaAlH₄.
[UPSC CSE Preliminary Examination (General Studies), 2002]
(A) A-3, B-4, C-1, D-2
(B) A-4, B-3, C-1, D-2
(C) A-3, B-4, C-2, D-1
(D) A-4, B-3, C-2, D-1
𝐀𝐧𝐬𝐰𝐞𝐫: (A) A-3, B-4, C-1, D-2
Explanation: Calcium in CaO₂ has oxidation state +2; aluminium in NaAlH₄ is +3; manganese in MnO₂ is +4; and sulphur in H₂S₂O₇ averages +6. Charge balance and standard oxidation-number conventions give the required matching.
