chemical engineering MCQs – Page 29

Practise multiple-choice questions from chemical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering Mcqs
561. A 2 kg object weighs 1.8 kgf on a spring balance. The value of g at that location in m/sec2 is___________________?
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A. 0.95

B. 8.82

C. 10.88

D. 9.81

562. Earing is a defect found in steels after the following metal working operation ?
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A. Extrusion

B. Rolling

C. Wire drawing

D. Deep drawing
563. Highest cutting speed is achieved by the _______________ tool material ?
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A. Plain carbon steel

B. Carbide

C. High speed steel

D. Cast alloy

564. Use of water as a manometric liquid suffers from the disadvantage of its____________________?
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A. High vapour pressure

B. Corrosive nature

C. Low vapour pressure

D. High boiling point

565. Which of the following materials has the poorest electrical conductivity ?
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A. Aluminium

B. Stainless steel

C. Carbon

D. Silver

566. The amount of water evaporated in kg per kg of fuel burnt in a boiler is called the ______________ of a boiler ?
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A. Evaporative capacity

B. Evaporation efficiency

C. Steam load

D. Thermal efficiency

567. For the Stokes law to be valid in the case of a falling sphere in a fluid, the_____________________?
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A. Flow around the sphere should be in turbulent region

B. Sphere must be metallic

C. Fluid density should be constant

D. Reynolds number (based on sphere diameter) should be < 1

568. A solid aluminium ball, when quenched in a water bath maintained at 40C, cools down from 550C to 450C in 20 seconds. The expected temperature of the ball after next 20 seconds may be about ____________________ C?
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A. 340

B. 320

C. 300

D. 370
569. ______________ wire is never used for making the heating element ?
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A. Invar

B. Nichrome

C. Kanthal

D. None of these

570. Hot dipping process is used for coating a low melting point metal (e.g. Pb, Sn, Zn) on iron, steel & copper having relatively higher melting points. Which of the following is not a hot dipping process ?
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A. Sherardizing

B. Galvanising

C. Tinning

D. None of these

571. In case of compression of one kg of air, the work done will be the least, when the value of polytropic index n is______________________?
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A. 1

B. 1.5

C. 1.4

D. Y = Cp/Cv

572. Starting friction is low in case of the ____________________ lubrication?
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A. Mixed/semi-fluid

B. Hydrodynamic

C. Hydrostatic

D. Boundary

573. Age hardening is connected with________________?
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A. Babbitt metal

B. Stainless steel

C. Duralumin

D. Gun metal

574. A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of thermal conductivity 0.14 W/m.K and thickness ______________ metre?
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A. 0.25

B. 0.1

C. 0.5

D. 0.01

575. For the irreversible reaction, Ca+ 2C = Ca C2 , ? H298 = 60000 J . mole-1 . If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved at 298 K will be__________________?
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A. 30,000 J

B. 60,000 J

C. 90,000 J

D. 2,40,000 J

576. When the wet steam is throttled but still remains wet at the exit of the throttle valve, then its temperature & dryness fraction respectively____________________?
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A. Decreases & increases

B. Increases & increases

C. Increases & decreases

D. Decreases & decreases

577. What is the pH of distilled water ?
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A. 0

B. 1

C. 14

D. 7
578. The type of pump used for lifting large quantity of sewage is a _________________ pump ?
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A. Centrifugal

B. Gear

C. Reciprocating

D. Plunger

579. Corrosion rate cannot be lowered by reducing the ________________ of the corroding medium?
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A. Velocity

B. None of these

C. Temperature

D. Concentration
580. For a first order chemical reaction, the concentration of the reactant decreases __________________ with time?
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A. Logarithmically

B. Exponentially

C. Linearly

D. Inversely