chemical engineering Mcqs
551. Specific gravity of hot metal (pig iron) is ______________ times that of the blast furnace slag ?
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A. 0.8

B. 2

C. 6

D. 3
552. Out of the following, the lowest packing of atoms exists in ____________________ crystal lattice structure?
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A. Face centred cubic (fcc)

B. Hexagonal close, packed (hcp)

C. Body centred cubic (bcc)

D. Simple cubic
553. A material being tested for endurance strength is subjected to the _____________ load?
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A. Impact

B. Dynamic

C. Completely reversed

D. Static & dynamic

554. Preheating before welding is done to____________________?
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A. Prevent cold cracks

B. Make the plate softer

C. Burn oil & grease sticking to plate surfaces

D. Avoid plate distortion

555. Photographic plates are coated with _____________________?
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A. Calcium silicate

B. Silver nitrate

C. Silver halide

D. Metallic silver

556. The laminar boundary layer thickness in zero pressure gradient flow over a flat plate along the x-direction varies as x0.5 while the thickness of turbulent boundary layer varies as (where, x = distance from the leading edge) ?
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A. x0.8

B. x1.5

C. x-0.8

D. x-1.5

557. The behaviour of a metal specimen, which when plastically strained in tension reduces its yield stress in compression and vice versa; is termed as the_______________?
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A. Stress recovery effect

B. Work hardening

C. Bauschinger effect

D. Creeping effect

558. The activity co-efficient of the solute in a dilute solution ?
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A. Remains constant

B. Increases with the increase of concentration of the solute

C. Decreases with the increase of concentration of the solute

D. Is unity at infinite dilution

559. The critical pressure at which the latent heat of vaporization of steam becomes zero is _____________ Kg/cm2 ?
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A. 225.65

B. 100.03

C. 273.15

D. 373.15

560. Out of the following _______________ iron has the best capability to bear sudden & excessive shocks?
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A. Wrought

B. Cast

C. White

D. Pig

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

581. Atomic _________________ of an element is a whole number ?
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A. Number

B. Radius

C. Volume

D. Weight

582. In a forced draft cooling tower, water is cooled from 95 to 80F by exposure to air with a wet bulb temperature of 70F. In this case, the________________?
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A. Range is 15F

B. Approach is 10F

C. Both A. & B.

D. Neither A. nor B.

583. Steel & cast iron pipes are produced by ______________ casting ?
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A. Slush

B. True centrifugal

C. Die

D. Investment

584. Tip of the match stick contains a mixture of________________?
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A. S + K2Cr2O7 + White P

B. None of these

C. K + S

D. K + S + K2Cr2O7

585. All the atoms of the world comprise of electrons, proton & neutron except that of ______________ atom in which neutron is absent ?
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A. Deuterium

B. Neon

C. Hydrogen

D. Helium

586. Pick out the wrong statement?
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A. Hardenability & Weldability of metals are inversely related

B. Covalent bonding formed by sharing of electrons is present in all semi-conductor materials

C. Copper is the metal having the highest electronic conductivity

D. Glass transition temperature applies to polymers but not to glasses

587. Which of the following pairs is not correctly matched ?
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A. Uranium 233 : Fertile material

B. Number of nucleons : Mass number

C. Scattering: Absorption cross-section

D. Binding energy : Mass defect

588. Water hammer is caused in steam carrying pipelines, because of ______________________?
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A. Vibration of the pipeline

B. Its exposure to torrential rain

C. High degree of superheat of steam

D. Partial condensation of steam
589. With increase in temperature, the electrical conductivity of a _________________ decreases ?
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A. Dielectric

B. Metal or alloy

C. None of these

D. Semi-conductor
590. Two solutions A1 & A2 have pH value of 2 & 6 respectively. It implies that the solution ?
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A. A1 is more alkaline than solution A2

B. A1 is highly acidic

C. A2 is very slightly acidic

D. Both B. & C.
591. An abrupt and sudden fall in the reading of barometer is an indication of the____________________?
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A. Clear weather

B. Storm

C. Rain

D. Cold wave

592. Steel rods are normally used for concrete reinforcement because concrete and steel have almost equal_________________?
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A. Youngs modulus

B. Thermal co-efficient of expansion

C. Compressive strength

D. Tensile strength

593. A fluid is termed as the Newtonian fluid, when the shear stress is _________________ the velocity gradient ?
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A. Inversely proportional to

B. Independent of

C. Directly proportional to

D. None of these

594. Consider an ideal solution of components A and B. The entropy of mixing per mole of an alloy containing 50% B is_______________?
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A. R ln 2

B. -R ln 2

C. 3 R ln 2

D. -3R ln 2

595. Spark plug is provided in a/an_________________?
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A. Engine having carburettor

B. Diesel engine

C. Compression ignition engine

D. Both B. & C.

596. _______________ rubber is generally used for making O rings used for vacuum sealings?
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A. Natural

B. Nitrile

C. Butadiene

D. Neoprene
597. Volumetric composition of flue gas analysed with the Orsat apparatus is : CO2 = 12%, O2 = 8%, CO = nil, N2 = 80%. This flue gas composition indicates that_________________?
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A. Hydrogen is not present in the fuel

B. Excess air has been used for combustion

C. Pure oxygen has been used for combustion

D. Nitrogen percentage in the fuel is very high

598. _____________ glass is used in the mercury in glass thermometer meant for measuring a temperature of 500C ?
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A. Supermax

B. Lead

C. High silica

D. Borosilicate

599. The pressure drop per unit length for laminar flow of fluid through a long pipe is proportional to (where, A = cross-sectional area of the pipe & D = Diameter of the pipe) ?
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A. 1/A2

B. D

C. 1/A

D. A

600. Viscoelastic behaviour is observed in _______________________ materials?
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A. All crystalline

B. Ceramic

C. Non-crystalline organic polymeric

D. All amorphous