All Free Chemical Engineering MCQs with Answers

• A. Nichrome
• B. Kanthal
• C. Invar
• D. None of these

Explanation: Invar is a low-expansion nickel-iron alloy designed for dimensional stability, not for high electrical resistance and heat generation.

• A. 250
• B. 500
• C. 1000
• D. 3000

Explanation: At break-even, fixed cost equals contribution from sales: production = 5000/(30 − 20) = 500 toys per month.

• A. Silver grey
• B. Black
• C. Green
• D. Yellow

Explanation: Steam lines are commonly identified with a silver-grey colour because the code associates this colour with steam and hot vapour service.

• A. Can't be used in the form of pressure sensitive tapes
• B. None of these
• C. Cure instantaneously after application on a surface
• D. Can't join two dissimilar metals

Explanation: Adhesives can be made as pressure-sensitive tapes and can join dissimilar metals, while most require time or a curing mechanism rather…

• A. Blow down valve
• B. Blow off cock
• C. Safety valve
• D. Fusible plug

Explanation: A fusible plug protects a boiler during low-water conditions by melting when its exposed portion overheats, releasing steam and warning of…

• A. Neoprene
• B. Natural
• C. Butadiene
• D. Nitrile

Explanation: Neoprene has good resistance to weathering, oils and vacuum-service conditions, making it a common choice for vacuum-sealing O-rings among…

• A. Deep drawing
• B. Rolling
• C. Extrusion
• D. Wire drawing

Explanation: Earing is the formation of uneven, ear-like projections around the rim of a drawn cup, caused mainly by sheet anisotropy during deep…

• A. Progress of work performed
• B. Sequence of operation to be performed
• C. Authorisation of work to be performed
• D. Balancing of load on machines

Explanation: Routing establishes the path of manufacture by specifying the sequence of operations, machines and work centres through which a job must…

• A. Slush
• B. Die
• C. True centrifugal
• D. Investment

Explanation: In true centrifugal casting, molten metal is poured into a rotating mould and centrifugal force produces sound cylindrical products such…

• A. Direct arc
• B. Induction
• C. Resistance
• D. Indirect arc

Explanation: Indirect-arc furnaces are commonly used for non-ferrous metals because the arc heats the charge indirectly and reduces contamination from…

• A. Hydrostatic
• B. Hydrodynamic
• C. Boundary
• D. Mixed/semi-fluid

Explanation: Hydrostatic lubrication supplies the pressurised lubricant film externally, even before the surfaces begin moving, so starting friction is…

• A. Water
• B. Steam
• C. Nitrogen
• D. Foam

Explanation: Nitrogen extinguishes a large fuel-gas-line fire by diluting and inerting the gas-air mixture, while also reducing the oxygen…

• A. 1000-1100
• B. 400-500
• C. 650-800
• D. 150-300

Explanation: Ordinary soft soldering uses low-melting alloys and is generally carried out at about 150–300°C.

• A. Formability
• B. Yield strength
• C. Toughness
• D. Resilience

Explanation: Automobile body sheets must undergo deep drawing and shaping without cracking, making formability the key property.

• A. Make the plate softer
• B. Prevent cold cracks
• C. Avoid plate distortion
• D. Burn oil & grease sticking to plate surfaces

Explanation: Preheating slows the cooling rate of the weld and reduces the formation of hard, brittle structures and hydrogen-induced cold cracks.

• A. Liquid iron
• B. Solid iron
• C. Sponge iron
• D. Iron saturated with carbon

Explanation: Direct reduction removes oxygen from iron ore in the solid state, so the product remains porous solid iron known as sponge iron.

• A. Vapour locking
• B. Hot starting
• C. All A, B & C
• D. Spark plug fouling

Explanation: Front-end volatility mainly influences vapour locking and hot starting because the most volatile components vaporise readily.

• A. Blades of gas turbine
• B. Piston of an I. C. engine
• C. Flywheel of steam engine
• D. Cycle chain

Explanation: Gas-turbine blades operate under high temperature and sustained stress, conditions that cause time-dependent creep deformation.

• A. High brittleness
• B. Higher tendency to distort
• C. High ductility
• D. None of these

Explanation: Refining the grain size generally improves steel strength and toughness and commonly gives good ductility compared with coarse-grained…

• A. 110
• B. 85
• C. 60
• D. 45

Explanation: An industrial noise exposure limit of about 85 dB is the commonly used international occupational-safety reference for an eight-hour…