{"id":12779,"date":"2025-09-23T03:39:36","date_gmt":"2025-09-23T02:39:36","guid":{"rendered":"https:\/\/mcqsadda.com\/?p=12779"},"modified":"2025-10-22T10:27:19","modified_gmt":"2025-10-22T09:27:19","slug":"metallurgy-top-100-mcqs-with-answer-and-explanation","status":"publish","type":"post","link":"https:\/\/mcqsadda.com\/index.php\/2025\/09\/23\/metallurgy-top-100-mcqs-with-answer-and-explanation\/","title":{"rendered":"Metallurgy Top 100 MCQs With Answer and Explanation"},"content":{"rendered":"\n

1. The process of extraction of metals from their ores is called:<\/mark><\/strong>
a) Refining
b) Concentration
c) Metallurgy
d) Smelting
Answer:<\/strong> c) Metallurgy
Explanation:<\/strong> Metallurgy is the science and technology of extracting and refining metals from their ores.<\/p>\n\n\n\n

2. Which of the following is a carbonate ore?<\/mark><\/strong>
a) Bauxite
b) Calamine
c) Hematite
d) Magnetite
Answer:<\/strong> b) Calamine
Explanation:<\/strong> Calamine (ZnCO\u2083) is a carbonate ore of zinc.<\/p>\n\n\n\n

3. The ore of aluminium is:<\/mark><\/strong>
a) Hematite
b) Bauxite
c) Galena
d) Cinnabar
Answer:<\/strong> b) Bauxite
Explanation:<\/strong> Aluminium is extracted from bauxite (Al\u2082O\u2083\u00b72H\u2082O).<\/p>\n\n\n\n

4. Haematite is an ore of:<\/strong><\/mark>
a) Copper
b) Zinc
c) Iron
d) Aluminium
Answer:<\/strong> c) Iron
Explanation:<\/strong> Haematite (Fe\u2082O\u2083) is a principal ore of iron.<\/p>\n\n\n\n

5. Galena is the chief ore of:<\/mark><\/strong>
a) Lead
b) Copper
c) Zinc
d) Silver
Answer:<\/strong> a) Lead
Explanation:<\/strong> Galena (PbS) is a sulphide ore of lead.<\/p>\n\n\n\n

6. Froth flotation method is used for the concentration of:<\/mark><\/strong>
a) Oxide ores
b) Sulphide ores
c) Carbonate ores
d) Nitrate ores
Answer:<\/strong> b) Sulphide ores
Explanation:<\/strong> Sulphide ores (like ZnS, PbS) are concentrated by froth flotation.<\/p>\n\n\n\n

7. Which gas is used in froth flotation to create bubbles?<\/mark><\/strong>
a) Oxygen
b) Carbon dioxide
c) Air
d) Hydrogen
Answer:<\/strong> c) Air
Explanation:<\/strong> Air is blown through the mixture to form froth that carries sulphide ore particles.<\/p>\n\n\n\n

8. Magnetic separation is suitable for:<\/mark><\/strong>
a) Ores of iron
b) Ores of aluminium
c) Ores of copper
d) Ores of silver
Answer:<\/strong> a) Ores of iron
Explanation:<\/strong> Magnetic ores like magnetite (Fe\u2083O\u2084) are concentrated by magnetic separation.<\/p>\n\n\n\n

9. The process of removing gangue from ore is called:<\/mark><\/strong>
a) Smelting
b) Roasting
c) Concentration
d) Refining
Answer:<\/strong> c) Concentration
Explanation:<\/strong> The gangue (earthy impurities) is removed by concentration methods.<\/p>\n\n\n\n

10. Which ore is concentrated by leaching?<\/mark><\/strong>
a) Haematite
b) Bauxite
c) Galena
d) Magnetite
Answer:<\/strong> b) Bauxite
Explanation:<\/strong> Bauxite is leached with sodium hydroxide in Bayer\u2019s process.<\/p>\n\n\n\n

11. The gangue present in bauxite ore is usually:<\/mark><\/strong>
a) Fe\u2082O\u2083 and SiO\u2082
b) PbS and Cu\u2082S
c) ZnS and CaCO\u2083
d) MnO\u2082 and MgO
Answer:<\/strong> a) Fe\u2082O\u2083 and SiO\u2082
Explanation:<\/strong> Bauxite is often associated with ferric oxide and silica as impurities.<\/p>\n\n\n\n

12. Which of the following is an ore of copper?<\/mark><\/strong>
a) Chalcopyrite
b) Malachite
c) Cuprite
d) All of these
Answer:<\/strong> d) All of these
Explanation:<\/strong> Chalcopyrite (CuFeS\u2082), Malachite (CuCO\u2083\u00b7Cu(OH)\u2082), Cuprite (Cu\u2082O) are copper ores.<\/p>\n\n\n\n

13. Which one is an ore of mercury?<\/mark><\/strong>
a) Cinnabar
b) Malachite
c) Galena
d) Bauxite
Answer:<\/strong> a) Cinnabar
Explanation:<\/strong> Cinnabar (HgS) is the main ore of mercury.<\/p>\n\n\n\n

14. Which process is used for the concentration of argentite (Ag\u2082S)?<\/mark><\/strong>
a) Gravity separation
b) Froth flotation
c) Magnetic separation
d) Electrolysis
Answer:<\/strong> b) Froth flotation
Explanation:<\/strong> Argentite (sulphide ore of silver) is concentrated by froth flotation.<\/p>\n\n\n\n

15. Cassiterite is the ore of:<\/mark><\/strong>
a) Tin
b) Iron
c) Zinc
d) Copper
Answer:<\/strong> a) Tin
Explanation:<\/strong> Cassiterite (SnO\u2082) is the chief ore of tin.<\/p>\n\n\n\n

16. Which is the gangue in Haematite?<\/mark><\/strong>
a) SiO\u2082
b) Al\u2082O\u2083
c) CaCO\u2083
d) MgCO\u2083
Answer:<\/strong> a) SiO\u2082
Explanation:<\/strong> Silica is the main gangue in haematite.<\/p>\n\n\n\n

17. The ore of zinc which is sulphide is:<\/mark><\/strong>
a) Calamine
b) Zincite
c) Sphalerite
d) Smithsonite
Answer:<\/strong> c) Sphalerite
Explanation:<\/strong> Sphalerite (ZnS) is a sulphide ore of zinc.<\/p>\n\n\n\n

18. Which one is an oxide ore?<\/mark><\/strong>
a) Magnetite
b) Galena
c) Cinnabar
d) Chalcopyrite
Answer:<\/strong> a) Magnetite
Explanation:<\/strong> Magnetite (Fe\u2083O\u2084) is an oxide ore of iron.<\/p>\n\n\n\n

19. The process of heating the ore in the absence of air is called:<\/mark><\/strong>
a) Roasting
b) Calcination
c) Smelting
d) Refining
Answer:<\/strong> b) Calcination
Explanation:<\/strong> Calcination is heating in the absence of air to remove volatile impurities.<\/p>\n\n\n\n

20. Which method is used to remove gangue from powdered ore using water flow?<\/mark><\/strong>
a) Leaching
b) Hydraulic washing
c) Froth flotation
d) Roasting
Answer:<\/strong> b) Hydraulic washing
Explanation:<\/strong> Hydraulic washing separates lighter gangue particles from heavier ore by water.<\/p>\n\n\n\n

21. Which is a sulphide ore of iron?<\/strong><\/mark>
a) Haematite
b) Magnetite
c) Iron pyrite
d) Siderite
Answer:<\/strong> c) Iron pyrite
Explanation:<\/strong> Iron pyrite (FeS\u2082) is a sulphide ore of iron.<\/p>\n\n\n\n

22. The ore of aluminium purified by Bayer\u2019s process is:<\/mark><\/strong>
a) Haematite
b) Bauxite
c) Galena
d) Magnetite
Answer:<\/strong> b) Bauxite
Explanation:<\/strong> Bayer\u2019s process is used for refining bauxite to alumina.<\/p>\n\n\n\n

23. Which metal is obtained from sphalerite?<\/mark><\/strong>
a) Iron
b) Zinc
c) Lead
d) Copper
Answer:<\/strong> b) Zinc
Explanation:<\/strong> Sphalerite (ZnS) is the chief ore of zinc.<\/p>\n\n\n\n

24. The separation of ore particles from gangue using difference in density is:<\/mark><\/strong>
a) Roasting
b) Gravity separation
c) Leaching
d) Froth flotation
Answer:<\/strong> b) Gravity separation
Explanation:<\/strong> Gravity separation uses density differences.<\/p>\n\n\n\n

25. Which of the following methods is used for gold concentration?<\/mark><\/strong>
a) Froth flotation
b) Leaching with cyanide
c) Magnetic separation
d) Hydraulic washing only
Answer:<\/strong> b) Leaching with cyanide
Explanation:<\/strong> Gold and silver are extracted from ores by leaching with NaCN solution.<\/p>\n\n\n\n

26. The process of heating an ore in excess of air is called:<\/mark><\/strong>
a) Calcination
b) Roasting
c) Smelting
d) Refining
Answer:<\/strong> b) Roasting
Explanation:<\/strong> Roasting involves heating sulphide ores in excess of air to convert them into oxides.<\/p>\n\n\n\n

27. Which of the following ores is concentrated by roasting?<\/mark><\/strong>
a) Haematite
b) Galena
c) Bauxite
d) Siderite
Answer:<\/strong> b) Galena
Explanation:<\/strong> Galena (PbS) is roasted to PbO, which is then reduced.<\/p>\n\n\n\n

28. In roasting, sulphide ores are converted into:<\/mark><\/strong>
a) Sulphates
b) Oxides
c) Chlorides
d) Carbonates
Answer:<\/strong> b) Oxides
Explanation:<\/strong> Sulphide ores + O\u2082 \u2192 Metal oxides + SO\u2082.<\/p>\n\n\n\n

29. The process used for carbonate ores is:<\/mark><\/strong>
a) Roasting
b) Calcination
c) Smelting
d) Electrolysis
Answer:<\/strong> b) Calcination
Explanation:<\/strong> Carbonate ores (like CaCO\u2083, ZnCO\u2083) decompose to oxides and CO\u2082 on calcination.<\/p>\n\n\n\n

30. Calcination of CaCO\u2083 gives:<\/mark><\/strong>
a) CaO + CO\u2082
b) CaCO\u2083 + H\u2082O
c) Ca + O\u2082
d) Ca(OH)\u2082
Answer:<\/strong> a) CaO + CO\u2082
Explanation:<\/strong> On calcination, calcium carbonate decomposes to quicklime and CO\u2082.<\/p>\n\n\n\n

31. Which ore is reduced by aluminothermic reduction?<\/mark><\/strong>
a) MnO\u2082
b) ZnO
c) Cu\u2082O
d) CaO
Answer:<\/strong> a) MnO\u2082
Explanation:<\/strong> MnO\u2082 + Al \u2192 Mn + Al\u2082O\u2083 (exothermic thermite reaction).<\/p>\n\n\n\n

32. The Ellingham diagram is used to predict:<\/mark><\/strong>
a) Magnetic properties
b) Reduction feasibility
c) Melting points
d) Hardness
Answer:<\/strong> b) Reduction feasibility
Explanation:<\/strong> Ellingham diagram relates \u0394G of oxide formation with temperature \u2192 helps in choosing reducing agents.<\/p>\n\n\n\n

33. Which reducing agent is used in blast furnace for iron extraction?<\/mark><\/strong>
a) H\u2082
b) C (coke)
c) Al
d) Na
Answer:<\/strong> b) C (coke)
Explanation:<\/strong> Coke acts as both fuel and reducing agent in blast furnace.<\/p>\n\n\n\n

34. Smelting is:<\/mark><\/strong>
a) Heating without air
b) Melting ore with reducing agent
c) Electrolytic refining
d) Removal of gangue
Answer:<\/strong> b) Melting ore with reducing agent
Explanation:<\/strong> Smelting extracts metals in molten state from their ores.<\/p>\n\n\n\n

35. In metallurgy, flux is used to:<\/mark><\/strong>
a) Reduce metal oxide
b) Remove impurities
c) Improve conductivity
d) Extract sulphur
Answer:<\/strong> b) Remove impurities
Explanation:<\/strong> Flux reacts with gangue \u2192 forms fusible slag.<\/p>\n\n\n\n

36. The flux used for silica impurity is:<\/mark><\/strong>
a) CaO
b) SiO\u2082
c) Na\u2082CO\u2083
d) MgO
Answer:<\/strong> a) CaO
Explanation:<\/strong> Acidic gangue (SiO\u2082) + basic flux (CaO) \u2192 CaSiO\u2083 (slag).<\/p>\n\n\n\n

37. The main function of limestone in blast furnace is:<\/mark><\/strong>
a) As a reducing agent
b) As a flux
c) To supply CO\u2082
d) To absorb heat
Answer:<\/strong> b) As a flux
Explanation:<\/strong> Limestone decomposes to CaO, which reacts with SiO\u2082 to form slag.<\/p>\n\n\n\n

38. Which of the following is not a method of reduction?<\/mark><\/strong>
a) Electrolytic reduction
b) Thermal reduction
c) Chemical reduction
d) Radioactive reduction
Answer:<\/strong> d) Radioactive reduction
Explanation:<\/strong> Metals are reduced by electrolytic, thermal, or chemical reduction but not by radioactive processes.<\/p>\n\n\n\n

39. Which reducing agent is used in the extraction of tungsten?<\/mark><\/strong>
a) C
b) H\u2082
c) Al
d) Na
Answer:<\/strong> b) H\u2082
Explanation:<\/strong> WO\u2083 + 3H\u2082 \u2192 W + 3H\u2082O. Hydrogen is used for reduction.<\/p>\n\n\n\n

40. Which metal is extracted by electrolytic reduction of its molten salt?
<\/mark><\/strong>a) Cu
b) Al
c) Fe
d) Zn
Answer:<\/strong> b) Al
Explanation:<\/strong> Aluminium is extracted from molten alumina (Hall-H\u00e9roult process).<\/p>\n\n\n\n

41. Which metal is obtained by electrolytic reduction of cryolite mixture?<\/mark><\/strong>
a) Fe
b) Al
c) Cu
d) Zn
Answer:<\/strong> b) Al
Explanation:<\/strong> Alumina dissolved in cryolite is electrolyzed to obtain aluminium.<\/p>\n\n\n\n

42. The role of cryolite in aluminium extraction is:<\/mark><\/strong>
a) Acts as flux
b) Lowers melting point of alumina
c) Increases conductivity
d) All of the above
Answer:<\/strong> d) All of the above
Explanation:<\/strong> Cryolite lowers melting point, increases conductivity, and acts as flux.<\/p>\n\n\n\n

43. The anode used in Hall-H\u00e9roult process is made of:<\/mark><\/strong>
a) Iron
b) Copper
c) Graphite
d) Aluminium
Answer:<\/strong> c) Graphite
Explanation:<\/strong> Graphite anode prevents contamination and conducts electricity.<\/p>\n\n\n\n

44. Which gas is released at the anode in aluminium extraction?<\/strong><\/mark>
a) O\u2082
b) CO\u2082
c) CO
d) H\u2082
Answer:<\/strong> b) CO\u2082
Explanation:<\/strong> O\u00b2\u207b ions discharge at anode \u2192 graphite anode oxidized \u2192 CO\u2082.<\/p>\n\n\n\n

45. Which process is used for extraction of highly reactive metals like Na, K, Ca?<\/mark><\/strong>
a) Smelting
b) Thermite reduction
c) Electrolytic reduction
d) Roasting
Answer:<\/strong> c) Electrolytic reduction
Explanation:<\/strong> Alkali and alkaline earth metals are extracted by electrolysis of their molten salts.<\/p>\n\n\n\n

46. Which reducing agent is used for extraction of copper from Cu\u2082O?<\/mark><\/strong>
a) C
b) Fe
c) CO
d) Cu
Answer:<\/strong> d) Cu
Explanation:<\/strong> Self-reduction: Cu\u2082O + Cu\u2082S \u2192 Cu + SO\u2082.<\/p>\n\n\n\n

47. Which process is used for the extraction of Zn from ZnO?<\/mark><\/strong>
a) Reduction with C
b) Electrolysis
c) Reduction with H\u2082
d) Reduction with Al
Answer:<\/strong> a) Reduction with C
Explanation:<\/strong> ZnO + C \u2192 Zn + CO.<\/p>\n\n\n\n

48. Which is reduced in blast furnace during Fe extraction?<\/mark><\/strong>
a) Fe\u2082O\u2083
b) Fe\u2083O\u2084
c) FeO
d) All of these
Answer:<\/strong> d) All of these
Explanation:<\/strong> In blast furnace, Fe\u2082O\u2083 \u2192 Fe\u2083O\u2084 \u2192 FeO \u2192 Fe (stepwise reduction).<\/p>\n\n\n\n

49. The chief reducing agent in blast furnace is:<\/mark><\/strong>
a) C
b) CO
c) H\u2082
d) Al
Answer:<\/strong> b) CO
Explanation:<\/strong> CO formed inside the furnace reduces Fe oxides to metallic Fe.<\/p>\n\n\n\n

50. The slag formed in blast furnace is:<\/mark><\/strong>
a) FeSiO\u2083
b) CaSiO\u2083
c) Al\u2082O\u2083
d) MgO
Answer:<\/strong> b) CaSiO\u2083
Explanation:<\/strong> Slag = CaO (from limestone) + SiO\u2082 (gangue) \u2192 CaSiO\u2083.<\/p>\n\n\n\n

51. The process of purifying impure metals is called:<\/mark><\/strong>
a) Smelting
b) Refining
c) Roasting
d) Calcination
Answer:<\/strong> b) Refining
Explanation:<\/strong> Refining removes impurities from a metal to obtain pure metal.<\/p>\n\n\n\n

52. Electrolytic refining is suitable for metals:<\/mark><\/strong>
a) Highly reactive
b) Less reactive
c) Only non-metals
d) Only alloys
Answer:<\/strong> b) Less reactive
Explanation:<\/strong> Metals like Cu, Ag, Zn, and Au are purified by electrolytic refining.<\/p>\n\n\n\n

53. In electrolytic refining, the impure metal is made the:<\/mark><\/strong>
a) Cathode
b) Anode
c) Electrolyte
d) Flux
Answer:<\/strong> b) Anode
Explanation:<\/strong> Impure metal is the anode; pure metal is deposited at cathode.<\/p>\n\n\n\n

54. The electrolyte in copper refining is:<\/mark><\/strong>
a) CuSO\u2084 + H\u2082SO\u2084 solution
b) NaCl solution
c) ZnSO\u2084 solution
d) KOH solution
Answer:<\/strong> a) CuSO\u2084 + H\u2082SO\u2084 solution
Explanation:<\/strong> Electrolyte contains Cu\u00b2\u207a ions for deposition of copper.<\/p>\n\n\n\n

55. Which of the following metals is refined by the Mond process?<\/mark><\/strong>
a) Ni
b) Cu
c) Zn
d) Al
Answer:<\/strong> a) Ni
Explanation:<\/strong> Nickel reacts with CO to form volatile Ni(CO)\u2084 \u2192 decomposed to pure Ni.<\/p>\n\n\n\n

56. What is the cathode reaction in electrolytic refining of copper?<\/mark><\/strong>
a) Cu\u00b2\u207a + 2e\u207b \u2192 Cu
b) Cu \u2192 Cu\u00b2\u207a + 2e\u207b
c) Cu\u00b2\u207a \u2192 Cu\u207a
d) Cu \u2192 Cu\u00b2\u207a
Answer:<\/strong> a) Cu\u00b2\u207a + 2e\u207b \u2192 Cu
Explanation:<\/strong> Cu\u00b2\u207a ions gain electrons at cathode \u2192 pure copper deposited.<\/p>\n\n\n\n

57. Which refining method uses selective oxidation?<\/mark><\/strong>
a) Electrolytic refining
b) Hydrometallurgy
c) Poling method
d) Zone refining
Answer:<\/strong> c) Poling method
Explanation:<\/strong> Poling involves blowing greenwood over molten impure copper to remove oxygen and impurities.<\/p>\n\n\n\n

58. Zone refining is used to purify:<\/mark><\/strong>
a) Metals with high melting points
b) Metals with low melting points
c) Semiconductors like Si and Ge
d) All metals
Answer:<\/strong> c) Semiconductors like Si and Ge
Explanation:<\/strong> Zone refining removes trace impurities from semiconductors.<\/p>\n\n\n\n

59. Cupellation is used to refine:<\/mark><\/strong>
a) Silver
b) Copper
c) Zinc
d) Aluminium
Answer:<\/strong> a) Silver
Explanation:<\/strong> Impure silver is heated with PbO \u2192 impurities oxidized \u2192 pure silver left.<\/p>\n\n\n\n

60. Which alloy contains copper and tin?<\/mark><\/strong>
a) Brass
b) Bronze
c) Steel
d) Amalgam
Answer:<\/strong> b) Bronze
Explanation:<\/strong> Bronze = Cu + Sn, used for statues, coins, and tools.<\/p>\n\n\n\n

61. Brass is an alloy of:<\/mark><\/strong>
a) Cu + Zn
b) Cu + Sn
c) Fe + C
d) Al + Cu
Answer:<\/strong> a) Cu + Zn
Explanation:<\/strong> Brass = copper + zinc, used in musical instruments, coins.<\/p>\n\n\n\n

62. Solder is an alloy of:<\/mark><\/strong>
a) Sn + Pb
b) Cu + Zn
c) Cu + Sn
d) Al + Mg
Answer:<\/strong> a) Sn + Pb
Explanation:<\/strong> Solder melts easily \u2192 joins metal parts.<\/p>\n\n\n\n

63. Duralumin is an alloy of:<\/mark><\/strong>
a) Al + Cu
b) Al + Mg
c) Fe + C
d) Cu + Zn
Answer:<\/strong> a) Al + Cu
Explanation:<\/strong> Duralumin is lightweight, strong \u2192 used in aircraft.<\/p>\n\n\n\n

64. Stainless steel is resistant to corrosion due to:<\/mark><\/strong>
a) Nickel content
b) Chromium content
c) Copper content
d) Zinc content
Answer:<\/strong> b) Chromium content
Explanation:<\/strong> Cr forms a passive oxide layer preventing rust.<\/p>\n\n\n\n

65. Which metal is refined by liquation?<\/mark><\/strong>
a) Tin
b) Lead
c) Zinc
d) Copper
Answer:<\/strong> b) Lead
Explanation:<\/strong> Lead is purified by melting with salt \u2192 impurities float.<\/p>\n\n\n\n

66. An amalgam is an alloy of:<\/mark><\/strong>
a) Mercury + metal
b) Copper + Tin
c) Iron + Carbon
d) Zinc + Copper
Answer:<\/strong> a) Mercury + metal
Explanation:<\/strong> Dental fillings often use amalgams.<\/p>\n\n\n\n

67. Aluminium is refined by:<\/mark><\/strong>
a) Hall-H\u00e9roult process
b) Mond process
c) Electrolytic refining
d) Poling method
Answer:<\/strong> a) Hall-H\u00e9roult process
Explanation:<\/strong> Alumina is electrolyzed in molten cryolite to give aluminium.<\/p>\n\n\n\n

68. Gold can be refined by:<\/mark><\/strong>
a) Aqua regia
b) Electrolytic refining
c) Both a and b
d) Roasting
Answer:<\/strong> c) Both a and b
Explanation:<\/strong> Gold dissolves in aqua regia (HCl + HNO\u2083) \u2192 pure Au precipitated; also refined electrolytically.<\/p>\n\n\n\n

69. The process of purifying metals by passing current through molten salt:<\/mark><\/strong>
a) Electrolytic refining
b) Poling
c) Cupellation
d) Distillation
Answer:<\/strong> a) Electrolytic refining
Explanation:<\/strong> Metals like Cu, Zn, Ni are purified by electrolysis.<\/p>\n\n\n\n

70. Aluminium alloys are mainly used for:<\/mark><\/strong>
a) Coins
b) Aircraft and rockets
c) Jewellery
d) Solder
Answer:<\/strong> b) Aircraft and rockets
Explanation:<\/strong> Aluminium alloys = lightweight + strong \u2192 aerospace applications.<\/p>\n\n\n\n

71. Which alloy is used for making coins?<\/mark><\/strong>
a) Brass
b) Bronze
c) Nickel-Copper alloy
d) Duralumin
Answer:<\/strong> c) Nickel-Copper alloy
Explanation:<\/strong> Durable and resistant to corrosion \u2192 coins.<\/p>\n\n\n\n

72. Type of steel used for cutting tools:<\/mark><\/strong>
a) Stainless steel
b) High carbon steel
c) Mild steel
d) Brass
Answer:<\/strong> b) High carbon steel
Explanation:<\/strong> High C content \u2192 hard, strong \u2192 suitable for cutting.<\/p>\n\n\n\n

73. Alloys of iron with carbon are called:<\/mark><\/strong>
a) Steel
b) Bronze
c) Brass
d) Duralumin
Answer:<\/strong> a) Steel
Explanation:<\/strong> Steel = Fe + C (0.2\u20132%) \u2192 mechanical strength enhanced.<\/p>\n\n\n\n

74. The main purpose of adding Cr in steel:<\/mark><\/strong>
a) Increase toughness
b) Prevent corrosion
c) Increase ductility
d) Reduce cost
Answer:<\/strong> b) Prevent corrosion
Explanation:<\/strong> Cr forms Cr\u2082O\u2083 layer \u2192 stainless steel resists rust.<\/p>\n\n\n\n

75. Nichrome is an alloy of:<\/mark><\/strong>
a) Nickel + Chromium
b) Nickel + Copper
c) Iron + Chromium
d) Iron + Nickel
Answer:<\/strong> a) Nickel + Chromium
Explanation:<\/strong> Nichrome is used in heating elements due to high resistance and stability.<\/p>\n\n\n\n

76. Which method is used for the extraction of highly reactive metals like K, Na, and Ca?<\/mark><\/strong>
a) Smelting
b) Electrolytic reduction of molten salts
c) Roasting
d) Poling
Answer:<\/strong> b) Electrolytic reduction of molten salts
Explanation:<\/strong> Reactive metals cannot be reduced chemically \u2192 extracted via electrolysis.<\/p>\n\n\n\n

77. Thermite process is mainly used for extraction of:<\/mark><\/strong>
a) Aluminium
b) Iron
c) Copper
d) Zinc
Answer:<\/strong> b) Iron
Explanation:<\/strong> Al reduces Fe\u2082O\u2083 \u2192 Fe + Al\u2082O\u2083 (exothermic reaction).<\/p>\n\n\n\n

78. Which method is used for extracting metals like Ti, Zr, and U?<\/mark><\/strong>
a) Electrolytic reduction
b) Kroll process
c) Mond process
d) Poling
Answer:<\/strong> b) Kroll process
Explanation:<\/strong> TiCl\u2084 or ZrCl\u2084 is reduced with Mg \u2192 pure metal.<\/p>\n\n\n\n

79. Which metal is extracted by Mond process?<\/mark><\/strong>
a) Copper
b) Nickel
c) Zinc
d) Aluminium
Answer:<\/strong> b) Nickel
Explanation:<\/strong> Ni + CO \u2192 Ni(CO)\u2084 (volatile) \u2192 decomposed to Ni.<\/p>\n\n\n\n

80. Which metal is obtained by electrolysis of fused cryolite?<\/mark><\/strong>
a) Copper
b) Aluminium
c) Zinc
d) Iron
Answer:<\/strong> b) Aluminium
Explanation:<\/strong> Aluminium is extracted from alumina dissolved in molten cryolite (Hall-H\u00e9roult process).<\/p>\n\n\n\n

81. Corrosion is:<\/mark><\/strong>
a) Formation of alloys
b) Oxidation of metals to stable oxides
c) Reduction of metal ions
d) Melting of metals
Answer:<\/strong> b) Oxidation of metals to stable oxides
Explanation:<\/strong> Corrosion is the slow deterioration of metals due to chemical reactions.<\/p>\n\n\n\n

82. Rusting occurs mainly in:<\/mark><\/strong>
a) Copper
b) Iron
c) Aluminium
d) Zinc
Answer:<\/strong> b) Iron
Explanation:<\/strong> Iron + O\u2082 + H\u2082O \u2192 Fe\u2082O\u2083\u00b7xH\u2082O (rust).<\/p>\n\n\n\n

83. The main component of rust is:<\/mark><\/strong>
a) FeO
b) Fe\u2082O\u2083\u00b7xH\u2082O
c) Fe\u2083O\u2084
d) Fe(OH)\u2082
Answer:<\/strong> b) Fe\u2082O\u2083\u00b7xH\u2082O
Explanation:<\/strong> Rust is hydrated ferric oxide.<\/p>\n\n\n\n

84. Which of the following prevents rusting by sacrificial protection?<\/mark><\/strong>
a) Zinc coating
b) Paint
c) Alloying
d) Oil coating
Answer:<\/strong> a) Zinc coating
Explanation:<\/strong> Zinc corrodes preferentially \u2192 protects iron (galvanization).<\/p>\n\n\n\n

85. Alluminium is resistant to corrosion due to:<\/mark><\/strong>
a) Oxide layer formation
b) Alloying
c) Painting
d) Zinc coating
Answer:<\/strong> a) Oxide layer formation
Explanation:<\/strong> Al forms a thin protective Al\u2082O\u2083 layer \u2192 prevents further corrosion.<\/p>\n\n\n\n

86. Which of the following methods is used to prevent rusting of iron?<\/strong><\/mark>
a) Painting
b) Oiling
c) Galvanization
d) All of the above
Answer:<\/strong> d) All of the above
Explanation:<\/strong> Rusting can be prevented by coatings, oiling, or sacrificial metal protection.<\/p>\n\n\n\n

87. Which metal is used in sacrificial anode method?<\/mark><\/strong>
a) Aluminium
b) Zinc
c) Copper
d) Iron
Answer:<\/strong> b) Zinc
Explanation:<\/strong> Zinc corrodes instead of iron \u2192 iron remains protected.<\/p>\n\n\n\n

88. Which of the following is a naturally occurring alloy?<\/mark><\/strong>
a) Steel
b) Brass
c) Electrum
d) Duralumin
Answer:<\/strong> c) Electrum
Explanation:<\/strong> Electrum = natural alloy of gold and silver.<\/p>\n\n\n\n

89. Bronze is an alloy of:<\/mark><\/strong>
a) Cu + Sn
b) Cu + Zn
c) Fe + C
d) Al + Cu
Answer:<\/strong> a) Cu + Sn
Explanation:<\/strong> Bronze is used for statues, coins, and bearings.<\/p>\n\n\n\n

90. Which of the following is used for making electrical wires?<\/mark><\/strong>
a) Aluminium
b) Copper
c) Zinc
d) Lead
Answer:<\/strong> b) Copper
Explanation:<\/strong> High conductivity and ductility \u2192 electrical applications.<\/p>\n\n\n\n

91. Which metal is used in thermocouples?<\/mark><\/strong>
a) Iron
b) Copper
c) Nickel
d) Aluminium
Answer:<\/strong> c) Nickel
Explanation:<\/strong> Nickel alloys are used in thermocouples due to stable emf generation.<\/p>\n\n\n\n

92. Stainless steel contains:<\/mark><\/strong>
a) Iron + Nickel + Chromium
b) Iron + Tin
c) Iron + Carbon only
d) Iron + Copper
Answer:<\/strong> a) Iron + Nickel + Chromium
Explanation:<\/strong> Chromium \u2192 corrosion resistance; Nickel \u2192 toughness.<\/p>\n\n\n\n

93. Nichrome is an alloy of:<\/mark><\/strong>
a) Nickel + Chromium
b) Nickel + Copper
c) Iron + Chromium
d) Copper + Zinc
Answer:<\/strong> a) Nickel + Chromium
Explanation:<\/strong> Used in heating elements \u2192 high resistivity + corrosion resistance.<\/p>\n\n\n\n

94. Which metal is used in aircraft manufacturing?<\/mark><\/strong>
a) Aluminium
b) Copper
c) Zinc
d) Lead
Answer:<\/strong> a) Aluminium
Explanation:<\/strong> Lightweight and strong \u2192 aerospace industry.<\/p>\n\n\n\n

95. Which of the following prevents oxidation of metals?<\/mark><\/strong>
a) Alloying
b) Painting
c) Oiling
d) All of the above
Answer:<\/strong> d) All of the above
Explanation:<\/strong> Coatings and alloying prevent direct contact with air\/water.<\/p>\n\n\n\n

96. Gold is used in jewellery because:<\/mark><\/strong>
a) High melting point
b) Resistance to corrosion
c) Easy to alloy
d) All of the above
Answer:<\/strong> d) All of the above
Explanation:<\/strong> Gold is malleable, ductile, and resistant \u2192 ideal for ornaments.<\/p>\n\n\n\n

97. Which of the following metals is extracted by self-reduction method?<\/mark><\/strong>
a) Copper
b) Aluminium
c) Zinc
d) Iron
Answer:<\/strong> a) Copper
Explanation:<\/strong> Cu\u2082O + Cu\u2082S \u2192 Cu + SO\u2082.<\/p>\n\n\n\n

98. The main application of aluminium alloys:<\/mark><\/strong>
a) Aircraft
b) Coins
c) Electrical wiring
d) Cutlery
Answer:<\/strong> a) Aircraft
Explanation:<\/strong> High strength-to-weight ratio \u2192 aerospace applications.<\/p>\n\n\n\n

99. Which metal forms a protective oxide layer naturally?<\/mark><\/strong>
a) Iron
b) Aluminium
c) Zinc
d) Lead
Answer:<\/strong> b) Aluminium
Explanation:<\/strong> Al\u2082O\u2083 layer protects aluminium from corrosion.<\/p>\n\n\n\n

100. Which method is used to prevent electrolytic corrosion?<\/mark><\/strong>
a) Sacrificial anode
b) Coating
c) Cathodic protection
d) All of the above
Answer:<\/strong> d) All of the above
Explanation:<\/strong> Electrolytic corrosion can be prevented by coating, sacrificial anode, or cathodic protection.<\/p>\n","protected":false},"excerpt":{"rendered":"

1. The process of extraction of metals from their ores is called:a) Refiningb) Concentrationc) Metallurgyd) SmeltingAnswer: c) MetallurgyExplanation: Metallurgy is the science and technology of extracting and refining metals from their ores. 2. Which of the following is a carbonate ore?a) Bauxiteb) Calaminec) Hematited) MagnetiteAnswer: b) CalamineExplanation: Calamine (ZnCO\u2083) is a carbonate ore of zinc.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[16033,16024,15886,15892,15876,15898,15901,15887,15899,15879,15883,16031,16027,16026,16029,15897,16038,16035,16034,16025,16032,16028,16037,15900,16030,16036,15896,15894],"class_list":{"0":"post-12779","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-chemistry","7":"tag-alloy-formation","8":"tag-chemistry-concepts","9":"tag-chemistry-formulas","10":"tag-chemistry-learning","11":"tag-chemistry-mcqs","12":"tag-chemistry-preparation-material","13":"tag-chemistry-questions-and-answers","14":"tag-chemistry-quiz","15":"tag-chemistry-revision","16":"tag-chemistry-study-material","17":"tag-competitive-exam-chemistry","18":"tag-corrosion-and-prevention","19":"tag-electrometallurgy","20":"tag-extraction-of-metals","21":"tag-hydrometallurgy","22":"tag-mcqs-for-chemistry-exam","23":"tag-metal-extraction-techniques","24":"tag-metallic-properties","25":"tag-metallurgical-processes","26":"tag-metallurgy","27":"tag-metallurgy-problems","28":"tag-ore-processing","29":"tag-physical-and-chemical-separation","30":"tag-psc-chemistry-mcqs","31":"tag-pyrometallurgy","32":"tag-refining-of-metals","33":"tag-ssc-chemistry-mcqs","34":"tag-upsc-chemistry-mcqs"},"_links":{"self":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12779","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/comments?post=12779"}],"version-history":[{"count":3,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12779\/revisions"}],"predecessor-version":[{"id":12942,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12779\/revisions\/12942"}],"wp:attachment":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/media?parent=12779"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/categories?post=12779"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/tags?post=12779"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}