chemical engineering chemical engineering basics Mcqs
551. 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. x-0.8

B. x0.8

C. x1.5

D. x-1.5

552. Which of the following can be manufactured using powder metallurgy techniques ?
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A. Bearings

B. All A, B and C

C. Carbide tool tips

D. Brake linings

553. ______________ cannot increase the fatigue strength of a material?
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A. Grain coarsening

B. Grain refining

C. Shot peening

D. Surface hardening

554. A fluid is termed as the Newtonian fluid, when the shear stress is _________________ the velocity gradient ?
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A. Independent of

B. None of these

C. Directly proportional to

D. Inversely proportional to

555. Euler number is defined as the ratio of inertia force to _______________ force?
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A. Gravity

B. Viscous

C. Pressure

D. Elastic

556. With decrease in the grain size of a material, its creep resistance___________________?
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A. Either A. or B.; depends on the material

B. Decreases

C. Increases

D. Remain constant
557. Hookes law_______________________?
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A. None of these

B. States that stress is inversely proportional to strain upto elastic limit

C. Applies to elastic deformation

D. Applies beyond limit of proportionality in stress-strain curve

558. For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm3) while the C.V. is same on weight basis (i.e., kcal/kg) ?
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A. Propane and LPG

B. B.F gas and coke oven gas

C. Sewage gas and gobar gas

D. Propane and acetylene

559. Identify the correct statement with reference to the extractive metallurgy of aluminium ?
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A. The electrolyte consists of molten Na3AlF6 with approximately 1 to 8% Al2O3

B. Anode effect sets in when the cryolite concentration goes below 40%.

C. Sodium is deposited along with aluminium, but is immediately vaporised

D. Approximately 80% of the aluminium deposited on the cathode comes from cryolite

560. In a boundary layer developed along the flow, the pressure decreases in the downstream direction. The boundary layer thickness in this case will _______________?
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A. Increase rapidly

B. Increase gradually

C. Remain constant

D. Decrease gradually

561. Work hardenable alloy steel used to make the bucket wheel excavators, blades of bulldozers and other earth moving equipments contain iron, carbon and ___________________?
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A. Manganese

B. Nickel

C. Chromium

D. Silicon

562. Flare tower used in industry is meant for_____________________?
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A. None of these

B. Absorbing the pollutant gases from the furnace exhaust

C. Cooling of furnace exhaust gases

D. Venting off (after burning) the excess inflammable/toxic gases at high pressure
563. Out of the following, the most malleable material is________________?
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A. Lead

B. Copper

C. Wrought iron

D. Aluminium

564. Electrometallurgy is not involved in the extraction of ___________________ from its ore?
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A. Aluminium

B. Tin

C. Lead

D. Both B. & C.
565. Limestone addition in the blast furnace is done to flux _______________ present in the raw materials?
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A. P

B. SiO2

C. Al2O3

D. MnO2

566. Cold chisel?s hammers are made of___________________?
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A. Forged steel

B. High carbon steel

C. Mild steel

D. High speed steel

567. _______________ is the most important element, which controls the physical properties of steel ?
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A. Vanadium

B. Manganese

C. Carbon

D. Silicon

568. 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. Bauschinger effect

B. Stress recovery effect

C. Creeping effect

D. Work hardening

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

B. Decreases with the increase of concentration of the solute

C. Is unity at infinite dilution

D. Increases with the increase of concentration of the solute

570. Increasing the carbon content of steel_________________?
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A. Reduces the upper shelf energy

B. Decreases hardness

C. Decreases brittleness

D. Increasing the ductility transition temperature
571. Unbreakable crockeries are made from ______________ polymers?
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A. Melamine

B. Polyurethane

C. Polystyrene

D. Polystyrene

572. The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1 T2)/T1. The co-efficient of performance (CO.P.) of a Carnot heat pump operating between T1 and T2 is given by_________________?
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A. T1/(T1-T2)

B. T2/(T1-T2)

C. T1/T2

D. T2/T1

573. Work study deals with the _______________ study?
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A. Time

B. Motion

C. Both A. & B.

D. Neither A. nor B.

574. A semi-conductor is damaged & behaves like a conductor, on passing a strong electric current through it, because it heats up the crystals & breaks the covalent bonds resulting in _______________ electrons ?
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A. None of these

B. Lack of free

C. Decrease in

D. Excess of
575. In ________________ process, there is an increase in entropy with no degradation of energy ?
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A. Isochoric heat addition

B. Isothermal expansion

C. Isobaric heat addition

D. Polytropic expansion

576. Air standard Otto cycle is more efficient than the diesel cycle for the same__________________?
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A. Compression ratio & pressure

B. Heat addition & compression ratio

C. Cylinder dimension & rpm

D. Heat addition & pressure

577. Most of the phosphorous present in the blast furnace burden enters into___________________?
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A. Flue gases

B. Slag

C. Hot metal

D. Refractory lining

578. ______________ wire is never used for making the heating element ?
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A. Invar

B. Nichrome

C. None of these

D. Kanthal

579. A thin, flat & square plate measuring 2 m 2 m is freely hanging in ambient air at 25C. It is exposed to the solar radiation falling on one side of the plate at the rate of 500 W/m2. The plate temperature will remain constant at 30C, if the convective heat transfer co-efficient is ________________ W/m2 C ?
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A. 100

B. 150

C. 200

D. 50

580. Out of the following the refractive index is the highest for____________________?
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A. Diamond

B. Kerosene

C. Brine

D. Glass

581. Pick out the wrong statement ?
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A. Both annealing and normalising release the internal stresses of the material besides improving

B. mechanical properties

C. Low carbon steel does not respond to the heat treatment for hardening of the material, hence it

D. subjected to case hardening or surface hardening processes like cyaniding, carburising,

E. riding etc., which produces high carbon outer layers resulting in increase of surface

F. dness

582. ______________ pipe is the most suitable for carrying sanitary drainage?
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A. Cast iron

B. Stainless steel

C. Asbestos cement

D. Reinforced cement concrete

583. ______________ is not used as the control rod material in a nuclear reactor ?
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A. Cobalt

B. Hafnium

C. Boron

D. Cadmium

584. In a furnace with heating element temperature at 1700C, the dominant mechanism of heat transfer will be__________________?
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A. Forced convection

B. Conduction

C. Radiation

D. Natural convection

585. The ratio of thermal & electrical conductivity is same for all the metals at the same temperature; and at around room temperature, this ratio is proportional to(where, T = absolute temperature, K) ?
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A. T2

B. T

C. 1/T

D. 1/T2

586. Which of the following phenomenon/ phenomena is/are diffusion controlled ?
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A. Dislocation climb

B. Recrystallisation

C. Cross-slip

D. Twinning

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

B. Wire drawing

C. Extrusion

D. Deep drawing
588. Oxyacetylene reducing flame is used while carrying out welding on__________________?
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A. Mild steel

B. High carbon steel

C. Grey cast iron

D. Alloy steel

589. Which of the following is resistant to the action of both heat & chemicals ?
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A. Soda lime glass

B. Borosilicate glass

C. None of these

D. Silica glass

590. Often earing defects are found during deep drawing operation, because the __________________?
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A. Sheet material has been given substantial spring back

B. Surface finish of the sheet is poor

C. Starting sheet has normal anisotropy due to its texture

D. Starting sheet has planer anisotropy due to its texture
591. 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

592. A compact estimate about the amount of materials handling between various work stations is obtained from the_____________________?
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A. Gantt chart

B. String diagram

C. Bin chart

D. Travel chart
593. Screws are specified by their _____________ diameters?
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A. Major

B. Pitch

C. None of these

D. Minor

594. Pick out the wrong statement about the machinability of metals. Machinability of a metal ?
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A. Decreases with increase in hardness, in general

B. Decreases with increase in strain hardening tendencies

C. Decreases with increases in tensile strength & decrease in grain size

D. Depend on the composition, microstructure and physical & mechanical properties

595. Age hardening is connected with________________?
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A. Duralumin

B. Gun metal

C. Babbitt metal

D. Stainless steel

596. Electrolytic reduction cell used for conversion of calcined Al2O3 to Al is a carbon lined furnace operating at 800-900 C. The purpose of electric current supplied to the furnace is to___________________?
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A. Achieve very high purity of aluminium (99.9%)

B. Keep the electrolyte in liquid condition by the generation of heat

C. Electrolytically dissociate alumina

D. Both B. & C.
597. An oxidation process is accompanied with decrease in the____________________?
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A. All A , B. & C.

B. Number of electrons

C. Oxidation number

D. Number of ions

598. The cathode in an electrochemical cell always carries____________________?
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A. Positive charge

B. Positive or negative charge depending upon the nature of the cell

C. Negative charge

D. Zero charge

599. For grinding of softer materials, the grinding wheel should have _________________ grain size ?
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A. Finer

B. Any type of

C. Coarser

D. Medium

600. The most suitable material for die casting is __________________?
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A. Nickel

B. Copper

C. Steel

D. Iron