61. Which is a renewable industrial resource?
A) Coal
B) Petroleum
C) Biomass
D) Natural gas
Answer: C
62. Which industry uses bauxite as raw material?
A) Iron industry
B) Aluminum industry
C) Copper industry
D) Steel industry
Answer: B
63. Aluminum is extracted by:
A) Electrolysis
B) Reduction with carbon
C) Oxidation
D) Distillation
Answer: A
64. The Hall-Héroult process is used for:
A) Iron extraction
B) Aluminum extraction
C) Copper refining
D) Zinc purification
Answer: B
65. Cryolite is used in aluminum extraction to:
A) Increase melting point
B) Decrease melting point
C) Act as fuel
D) Act as catalyst
Answer: B
66. Which metal is obtained from chalcopyrite?
A) Iron
B) Copper
C) Zinc
D) Lead
Answer: B
67. Electrorefining is used to:
A) Extract metal
B) Purify metal
C) Oxidize metal
D) Reduce metal
Answer: B
68. Galvanization is coating iron with:
A) Copper
B) Zinc
C) Tin
D) Aluminum
Answer: B
69. Stainless steel contains:
A) Iron and copper
B) Iron, chromium, nickel
C) Iron and zinc
D) Iron and aluminum
Answer: B
70. Which industry uses sulfuric acid extensively?
A) Fertilizer
B) Textile
C) Petroleum
D) All of these
Answer: D