Free Plant Design and Economics MCQs with Answers

• A. 0.35 to 0.5
• B. 0.1 to 0.35
• C. 0.8 to 1.4
• D. 1 to 1. 5

Explanation: Medium-carbon steel is commonly classified as containing about 0.3 to 0.6% carbon; among the choices, 0.35 to 0.5% is the appropriate…

• A. Normalising
• B. Tempering
• C. Annealing
• D. None of these

Explanation: Tempering reheats hardened steel below its critical temperature, reducing excessive hardness and brittleness while improving toughness.

• A. Phenol
• B. Acetic acid
• C. Ammonia
• D. Formaldehyde

Explanation: Ammonia is normally transported in strong steel containers because it is volatile and is commonly handled as a pressurised liquefied gas.

• A. Do not require heat treatment for any of its applications
• B. Is tempered at 850°C
• C. Do not have good resilience properties
• D. Are used for leaf and coiled springs

Explanation: Silico-manganese steel combines strength, elasticity and good fatigue resistance, making it suitable for leaf springs and coiled springs.

• A. Wood
• B. Copper bearing steel
• C. Concrete
• D. Porcelain

Explanation: Molasses fermentation vessels for alcohol production are commonly made from copper-bearing steel, which provides suitable strength and…

• A. Aluminium
• B. Lead
• C. Iron
• D. Nickel

Explanation: Iron or mild steel is used for mercury containers because mercury does not readily amalgamate with iron, unlike aluminium, lead, nickel…

• A. Silicone rubber, teflon, porcelain and wood
• B. Nickel, monel, stainless steel and graphite
• C. Aluminium, copper, high silicon iron
• D. Brass, cast iron, mild steel and tin

Explanation: At 40°C, glacial acetic acid can attack brass, cast iron, mild steel and tin, making this group unsuitable.

• A. Steel
• B. Concrete
• C. Zircaloy
• D. Graphite

Explanation: A steel thermal shield is placed inside high-powered reactors to absorb radiation and heat, protecting the reactor walls or vessel from…

• A. Hydrochloric acid
• B. All A., B. and C.
• C. Chlorine (dry or wet)
• D. SO2 (dry or wet)

Explanation: Hydrochloric acid, sulphur dioxide and chlorine can all chemically attack or deteriorate wood, especially when moisture is present.

• A. Hot rolled
• B. Chrome carbon
• C. Cold rolled
• D. Stainless

Explanation: Bicycle-frame tubes are commonly made from cold-rolled steel because cold working gives a smooth finish, accurate dimensions and improved…

• A. Under stressing the specimen
• B. Rise in temperature
• C. Having notches in the specimen
• D. Having scratches on the surface

Explanation: Controlled understressing can increase fatigue strength through coaxing, which stabilizes the material against repeated loading.

• A. Toughness
• B. Creep limit
• C. Stiffness
• D. All A., B. & C.

Explanation: Oxide formation during atmospheric exposure can impair high-temperature strength by reducing the creep limit.

• A. Monel
• B. Graphite
• C. Stainless steel
• D. Kel-F and Teflon

Explanation: Stainless steel is unsuitable for aqueous hydrofluoric acid at 100°C because fluoride ions destroy its protective passive film and cause…

• A. Cast iron
• B. Monel
• C. Karbate
• D. Aluminium or chromium alloys (Cr > 18% for cold acid)

Explanation: Aluminium and chromium-rich alloys become protected by a passive oxide film in concentrated nitric acid, making them suitable storage…

• A. Monel
• B. Stainless steel type 304
• C. Nickel
• D. Carbon steel

Explanation: Monel provides strong resistance to fuming sulphuric acid and is therefore used where ordinary steels or common stainless steels may…

• A. Is lined with lead
• B. Need not be lined
• C. Is lined with rubber
• D. Is lined with acid-proof bricks

Explanation: Oleum can be stored in a suitably designed carbon-steel tower without a lead, rubber or brick lining because concentrated sulphuric acid…

• A. Ammonia (both aqueous & anhydrous)
• B. Fruit juices, milk & its products and caustic soda solution
• C. Nitric acid & hydrochloric acid (concentrated)
• D. Sulphuric acid (concentrated)

Explanation: Nickel equipment is valued for resistance to caustic soda and for hygienic handling of food products such as milk and fruit juices.

• A. Very high cost
• B. Very low strength to weight ratio
• C. Rather low tensile strength
• D. Scarce availability

Explanation: Aluminium has a comparatively low tensile strength in its unalloyed or common forms, although it is light and therefore can still have a…

• A. Aluminium
• B. Silver
• C. Calcium
• D. Iron

Explanation: Aluminium rapidly forms a thin, adherent aluminium oxide film that isolates the underlying metal from air and moisture.

• A. Stainless steel
• B. Cast iron
• C. Lead lined steel
• D. Rubber lined steel

Explanation: Cast iron has good resistance to concentrated sulphuric acid at about 98% concentration and is therefore used for such coolers.