Free Chemical Process Principles MCQs with Answers

• A. Briquettes
• B. Oil gas
• C. Wood
• D. Pitch creosote mixture

Explanation: Wood is a naturally occurring fuel, whereas briquettes, oil gas, and pitch-creosote mixtures are manufactured or processed fuels.

• A. Computing the excess/deficiency of combustion air
• B. Calculation of flue gas temperature
• C. Computation of flue gas analysis
• D. None of these

Explanation: An Ostwald chart relates flue-gas composition to the amount of air supplied, allowing excess or deficient combustion air to be estimated.

• A. Boiler furnace
• B. Walking beam reheating furnace
• C. Soaking pits
• D. Rotary kilns

Explanation: A boiler furnace transfers combustion heat efficiently to water through the boiler surfaces, giving it higher thermal efficiency than…

• A. Combustion air
• B. Feedwater
• C. Pulverised coal
• D. Furnace oil

Explanation: An economiser recovers heat from boiler flue gas to raise the temperature of the incoming feedwater before it enters the boiler.

• A. Ammonia
• B. Fine dolomite
• C. None of these
• D. Alkaline powders

Explanation: Ammonia, dolomite, and alkaline powders can neutralise acidic sulphur oxides and suppress the acid dew point of flue gas.

• A. Furnace oil with air
• B. Furnace oil with oxygen
• C. Blast furnace gas with air
• D. Blast furnace gas with oxygen

Explanation: Blast-furnace gas contains large amounts of inert nitrogen and other diluents, so burning it with air produces a large flue-gas mass and…

• A. Non-preheated combustion air
• B. Stoichiometric combustion air
• C. Combustion air not enriched with oxygen
• D. Recuperators

Explanation: Exact stoichiometric air gives no allowance for mixing limitations, so complete combustion cannot reliably be achieved throughout an…

• A. Higher power consumption in its transportation
• B. Excessive fly ash discharge from the stack
• C. Ash disposal problem
• D. Erosion of induced draft fan blades

Explanation: Pulverised coal produces a large quantity of fine ash, creating difficult and costly ash-collection and disposal problems.

• A. Oxidising
• B. Inert
• C. Reducing
• D. Decarburising

Explanation: The blast furnace must maintain a reducing atmosphere so iron oxides lose oxygen and form metallic iron.

• A. Diffusion
• B. Outside mixing type
• C. Rotary
• D. Premix

Explanation: A premix burner mixes the fuel and air before the mixture reaches the burner outlet, allowing combustion to begin with a prepared mixture.

• A. Preheating the combustion air
• B. All A., B. & C.
• C. Preheating the fuel gas
• D. Oxygen enrichment of combustion air

Explanation: Preheating either reactant reduces the heat required to reach flame temperature, while oxygen enrichment reduces the inert nitrogen load…

• A. Transportation of coal
• B. Drying of coal
• C. Combustion of coal by supplying it around the burner
• D. Preheating the primary air

Explanation: Primary air carries and often dries the pulverised coal, whereas secondary air is introduced around the burner to supply the oxygen needed…

• A. Tar content in producer gas
• B. C. V. of producer gas
• C. Temperature of producer gas
• D. Fusion of coal ash & clinker formation

Explanation: Steam moderates the temperature in a producer-gas furnace and helps prevent the ash from fusing into clinker.

• A. Is the removal of carbon from iron carbide (Fe3C)
• B. All A., B. and C.
• C. Is favoured by CO2
• D. Affects its crystalline structure

Explanation: Decarburisation removes carbon from iron carbide, Fe₃C, and changes the steel's composition and structure; oxidising gases such as CO₂…

• A. Is the hardest metal in common use
• B. Is the lightest metal in common use
• C. Cannot be scratched by finger nails
• D. Cannot be work hardened

Explanation: Lead is exceptionally soft and does not significantly undergo work hardening during deformation.

• A. Quartz
• B. Fluorite
• C. Feldspar
• D. Gypsum

Explanation: On the Mohs scale, talc has hardness 1 and gypsum has hardness 2, making gypsum the next softest standard mineral.

• A. Die with hammer
• B. Workpiece
• C. Hammer
• D. Weight on hammer

Explanation: In drop forging, the upper die is attached to a hammer or ram and is dropped at high velocity onto the workpiece held in the lower die.

• A. Low carbon steel
• B. Wrought iron
• C. Mild steel
• D. White cast iron

Explanation: Wrought iron contains very little carbon, generally below about 0.1%, whereas low-carbon and mild steels contain more and white cast iron…

• A. Aluminium
• B. Magnesium
• C. Arsenic copper
• D. Nickel

Explanation: Locomotive boiler tubes commonly use arsenical copper alloys because a small amount of arsenic improves resistance to corrosion and…

• A. Phosphorous and tungsten
• B. Molybdenum and tungsten
• C. Lead and vanadium
• D. Nickel and chromium

Explanation: Nickel and chromium improve steel’s resistance to oxidation and corrosion, with chromium forming a protective passive oxide film.