Free Plant Design and Economics MCQs with Answers

• A. Non-ferrous metals
• B. Cast iron
• C. Stainless steel
• D. Low carbon steel

Explanation: Galvanising coats steel with zinc, and low-carbon steel is the usual substrate because it is economical and readily coated.

• A. Glass
• B. Cermet
• C. Thermosetting plastic
• D. Metallic alloy

Explanation: Vycor is a porous high-silica glass that withstands thermal shock and high temperatures, which suits it for protective thermal wells.

• A. PVC
• B. Iron or steel
• C. Nickel
• D. Brass

Explanation: Dry chlorine does not attack ordinary iron or steel severely, so steel equipment can be used when moisture is excluded.

• A. Silicon carbide
• B. Fireclay
• C. Silica
• D. Corundum

Explanation: Beehive coke ovens are lined and constructed with silica bricks because silica provides the refractory strength needed at coke-making…

• A. Copper, nickel and Monel
• B. Mild steel and stainless steel
• C. Cast iron, tin and aluminium
• D. High silicon iron, silicon rubber, Kel-F and Teflon

Explanation: Wet chlorine is highly corrosive, while dry chlorine also requires carefully selected materials, so high-silicon iron, silicon rubber…

• A. Is used as an alloying element for both ferrous & non-ferrous alloys
• B. Is paramagnetic below 415° C (its Curie temperature)
• C. Diamagnetic
• D. Has a body centred cubic (bcc) crystal lattice structure

Explanation: Nickel is widely used as an alloying element in both ferrous and non-ferrous alloys.

• A. Price
• B. Abundant availability
• C. Thermal conductivity
• D. Corrosion resistance

Explanation: Tin is much less abundant than lead, so tin-based bearing alloys are generally more expensive and less readily available.

• A. Phosphoric acid
• B. Sulphuric acid
• C. Fluorine (dry or wet)
• D. None of these

Explanation: Fluorine attacks the silica network of glass, forming volatile silicon fluorides and related fluorinated products.

• A. Zinc
• B. Tin
• C. Copper
• D. Molybdenum

Explanation: Monel is principally a nickel-copper alloy, commonly containing roughly two-thirds nickel and one-third copper.

• A. 6
• B. 5
• C. 3
• D. 2

Explanation: A body-centred cubic unit cell has eight corner atoms contributing 8 × 1/8 = 1 atom, plus one complete atom at the centre.

• A. Phosphorous bronze
• B. Mild steel
• C. White metal alloys
• D. None of these

Explanation: Bush bearings are commonly made from phosphor bronze because it combines good bearing properties, strength, wear resistance and…

• A. Tensile strength
• B. Corrosion resistance
• C. Cutting ability
• D. None of these

Explanation: Cobalt increases the hot hardness and red-hardness of steel, allowing cutting tools to retain their hardness at elevated temperatures.

• A. Molybdenum
• B. Vanadium
• C. Chromium
• D. Phosphorus

Explanation: Chromium, molybdenum and vanadium are carbide-forming alloying elements in steel.

• A. Anhydrous ammonia
• B. Fatty acids
• C. Hydrochloric acid (95%)
• D. Sulphuric acid (25%)

Explanation: Dry anhydrous ammonia is stored safely in mild-steel vessels because it does not significantly attack carbon steel under suitable…

• A. Induction
• B. Age
• C. Work
• D. Flame

Explanation: Plastic deformation during cold working increases dislocation density, making the metal harder and stronger but less ductile.

• A. Grey cast iron
• B. Pig iron
• C. White cast iron
• D. Nodular cast iron

Explanation: Nodular cast iron contains graphite in rounded nodules, which disturb the metal matrix less than the flakes in grey iron and give much…

• A. Iron, nickel and chromium
• B. Tin, zinc and nickel
• C. Copper and nickel
• D. Copper and tin

Explanation: Inconel is primarily a nickel-based alloy containing substantial chromium and iron, with other additions depending on grade.

• A. Copper
• B. Cast iron
• C. Aluminium
• D. High carbon steel

Explanation: Cast iron is used for the methane-chlorination mixing vessel because it provides suitable resistance to the chlorinating environment and…

• A. Brass for low
• B. Nickel alloys for high
• C. Aluminium for all
• D. Both A. & B.

Explanation: Bimetallic thermometers use metals with different thermal expansion coefficients: brass-based combinations are used for lower…

• A. 18-20
• B. 6-8
• C. 30-35
• D. 50-55

Explanation: Typical high-speed tool steel contains about 18% tungsten, often with chromium, vanadium and carbon.