All Free Chemical Engineering MCQs with Answers

• A. Asbestos cement
• B. Steel
• C. Cement concrete
• D. Stoneware

Explanation: Steel sewer pipes have high strength and can withstand the internal pressure and mechanical stresses associated with pressurised sewage…

• A. Mean
• B. Inside
• C. Outside
• D. None of these

Explanation: Boiler tube dimensions are conventionally specified by wall thickness and outside diameter.

• A. Impact
• B. Torsion
• C. Charpy
• D. Hardness

Explanation: A hardness test leaves a small permanent indentation or other local mark, so it is commonly classified as semi-destructive.

• A. Tungsten, chromium & cobalt
• B. Nickel, cobalt & chromium
• C. Manganese, chromium & cobalt
• D. Tungsten, molybdenum & nickel

Explanation: Stellite alloys are cobalt-based hard-facing alloys whose important alloying elements include chromium and tungsten.

• A. 5
• B. 10
• C. 20
• D. 35

Explanation: Brasses containing more than about 20% zinc are especially prone to season cracking when residual tensile stress is present.

• A. Vacancy
• B. Dislocation
• C. All of these
• D. Grain boundary

Explanation: Annealing allows vacancies to diffuse, dislocations to recover, and grains to grow, reducing the densities of these defects in the…

• A. Descaling
• B. Shot blasting
• C. Pickling
• D. Skimming

Explanation: Pickling removes oxide scale from hot-rolled steel by chemical action, commonly using an acid bath.

• A. Steam jet arrangement
• B. Induced draught fan
• C. Forced draught fan
• D. Chimney

Explanation: Locomotive boilers commonly use a steam jet arrangement to create draught: exhaust steam expands through a nozzle and entrains combustion…

• A. Aluminium
• B. Stainless steel
• C. Brass
• D. Copper

Explanation: Stainless steel generally has a lower scrap value than aluminium, brass, or copper because its valuable alloy constituents are diluted by…

• A. Creep resistance
• B. Malleability
• C. Stiffness
• D. Tensile strength

Explanation: Young's modulus is the ratio of elastic stress to elastic strain and indicates how strongly a material resists elastic deformation.

• A. Machinability
• B. Density
• C. Plastic deformation
• D. Strength

Explanation: Compared with metals, plastics generally have lower mechanical strength and stiffness, although their low density and corrosion resistance…

• A. Copper
• B. Graphite
• C. Stainless steel
• D. Steel

Explanation: Copper is used for resistance-welding electrodes because its high electrical and thermal conductivity limits electrode heating while…

• A. Plastic deformation of material does not occur
• B. Initiation of crack from below the surface does not occur
• C. Initiation of crack occurs on the surface of the machine part
• D. Presence of both rough & smooth zone with conchoidal markings in smooth zone of the

Explanation: Fatigue cracks commonly start at the surface, but subsurface initiation can occur at inclusions or other internal defects.

• A. Bending & tension
• B. Shear
• C. Compression
• D. Tension

Explanation: Tightening the nut stretches the bolt and produces tensile preload in it, while the clamped parts experience compression.

• A. Soft iron
• B. Copper
• C. Mild steel
• D. Stainless steel

Explanation: Soft iron binding wire is commonly used to hold soldered parts firmly during heating and cooling.

• A. Induction motor
• B. Electrostatic precipitator
• C. Fast breeder reactor
• D. Magneto hydrodynamic generator (MHD)

Explanation: An electrostatic precipitator creates corona discharge to charge suspended dust particles, which are then attracted to oppositely charged…

• A. Air filter
• B. Exhaust silencer
• C. Fuel injector
• D. Battery

Explanation: In the conventional comparison, a diesel engine requires a fuel injector, whereas a petrol SI engine traditionally uses a carburettor.

• A. Nipple
• B. Bell and spigot
• C. Union
• D. Socket

Explanation: A socket joint is commonly used for joining pipes carrying water at low pressure, with one pipe end fitting into the socket of another.

• A. Yield
• B. Compressive
• C. Tensile
• D. Bearing

Explanation: The factor of safety compares the limiting strength, commonly yield stress for ductile materials, with the allowable or working stress.

• A. Decarburising
• B. Alloying with cobalt
• C. Purification
• D. Alternate heating & cooling

Explanation: Adding cobalt to iron improves its magnetic properties, including magnetic permeability, because cobalt supports strong ferromagnetism.