Free Plant Design and Economics MCQs with Answers
803 Plant Design and Economics MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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- A. Harden the surface
- B. Prevent the action of water
- C. Increase its glossiness and lustre
- D. Prevent the action of oxygen
Explanation: Galvanising coats iron with zinc, isolating it from moisture and forming a sacrificial protective layer.
Correct answer: Prevent the action of water- A. Eutectic
- B. Upper critical
- C. Recrystallisation
- D. Lower critical
Explanation: Recrystallisation is the formation of new, strain-free grains when a cold-worked metal is heated sufficiently.
Correct answer: Recrystallisation- A. Alumel
- B. Constantan
- C. Chromel
- D. Invar
Explanation: Invar is an iron-nickel alloy containing about 36% nickel and is used where extremely low thermal expansion is required.
Correct answer: Invar- A. Steel
- B. Cast iron
- C. Brass
- D. Gun metal
Explanation: Concentrated caustic soda is commonly stored in steel drums because carbon steel has satisfactory resistance under ordinary storage…
Correct answer: Steel- A. Cobalt
- B. Nickel
- C. Tungsten
- D. Chromium
Explanation: Cobalt increases the coercivity and residual magnetism of steel, making cobalt steels suitable for permanent magnets.
Correct answer: Cobalt- A. Stainless steel
- B. Cast iron
- C. Mild steel
- D. Monel
Explanation: Sugar-cane mills use heavy cast-iron rolls because cast iron withstands the large compressive loads and provides a durable, wear-resistant…
Correct answer: Cast iron- A. Moving mercury and graphite
- B. Moving mercury and carbon
- C. Graphite and moving mercury
- D. Moving mercury and crimped steel wire
Explanation: In a mercury cell, graphite or another suitable inert material serves as the anode, while flowing mercury is the cathode.
Correct answer: Graphite and moving mercury- A. Protected from rusting
- B. Harder
- C. Alumina coated iron
- D. None of these
Explanation: Galvanised iron has a zinc coating that separates the iron from the atmosphere and also provides sacrificial protection if the coating is…
Correct answer: Protected from rusting- A. Parkerising
- B. Sherardizing
- C. Anodising
- D. None of these
Explanation: Sherardising is a zinc diffusion coating process in which zinc powder diffuses into the surface of iron or steel during heating.
Correct answer: Sherardizing- A. Abrasive
- B. Reinforced
- C. Refractory
- D. Fully metallic
Explanation: Cermets combine a ceramic phase with a metallic phase and retain the hardness and high-temperature resistance associated with refractory…
Correct answer: Refractory- A. Glass lined steel
- B. Nickel clad steel
- C. Lead lined steel
- D. Aluminium
Explanation: Molten phthalic anhydride is commonly stored in aluminium vessels because aluminium offers suitable resistance to the molten product.
Correct answer: Aluminium- A. Tungsten, chromium and vanadium
- B. Tungsten, vanadium and chromium
- C. Vanadium, chromium and tungsten
- D. Chromium, tungsten and vanadium
Explanation: The designation 18-4-1 for high-speed steel refers to approximately 18% tungsten, 4% chromium and 1% vanadium.
Correct answer: Tungsten, chromium and vanadium- A. Non-ferrous metals
- B. Low carbon steels
- C. Non-metals
- D. Stainless steel
Explanation: Low-carbon steel sheets are commonly galvanised because zinc protects the exposed steel both as a barrier and through sacrificial action.
Correct answer: Low carbon steels- A. Monel metal
- B. Babbitt metal
- C. German silver
- D. Dow metal
Explanation: Dow metal is a magnesium-based alloy, usually containing aluminium and other additions, so it has low density and is classified as a light…
Correct answer: Dow metal- A. Meehanite
- B. Magnalium
- C. Gun metal
- D. Muntz metal
Explanation: Meehanite is a controlled-quality cast iron, so it is a ferrous alloy. Magnalium, gun metal and Muntz metal are copper- or aluminium-based…
Correct answer: Meehanite- A. Copper
- B. Stainless steel
- C. Copper alloys
- D. Monel
Explanation: Stainless steel is used for the bulb and capillary because mercury does not readily amalgamate with it, allowing reliable pressure…
Correct answer: Stainless steel- A. Cast iron and high silicon iron
- B. Mild steel and stainless steel
- C. Aluminium, tin and rubber
- D. Teflon, glass and porcelain
Explanation: Aluminium, tin and rubber are unsuitable for storing 100% sulphuric acid at 30°C because the acid can attack or damage these materials.
Correct answer: Aluminium, tin and rubber- A. Enough plasticity
- B. High toughness
- C. Low co-efficient of friction
- D. Low thermal conductivity
Explanation: A bearing metal should conduct heat away from the bearing surface, so low thermal conductivity is undesirable.
Correct answer: Low thermal conductivity- A. Both A. & B.
- B. Protect the base metal by cathodic protection
- C. Prevent its rusting by contact with corrosive atmosphere
- D. Neither A. nor B.
Explanation: Zinc galvanising forms a physical barrier against the atmosphere and also acts sacrificially, corroding preferentially to protect exposed…
Correct answer: Both A. & B.- A. Cast iron
- B. Steel
- C. Stainless steel
- D. Bronze
Explanation: Steel balls provide the hardness and impact resistance needed for grinding while remaining economical.
Correct answer: Steel