chemical engineering Mcqs
451. Which of the following low melting alloy containing bismuth and lead is used for electric fuse ?
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A. Monel metal

B. Babbitt metal

C. Duralumin

D. Woods metal
452. If the demand for an item is trebled and the order cost is reduced to one third, then the economic order quantity_________________?
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A. Remains unchanged

B. Is trebled

C. Decreases by a factor of 3

D. Decreases by a factor of 1/3

453. The most economical channel section for the fluid flow is the one for which the discharge is maximum for a given cross-sectional area. Vertical velocity distribution in an open channel for laminar flow can be assumed to be_______________?
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A. Straight line

B. None of these

C. Parabolic

D. Hyperbolic

454. In the Bayers process, bauxite is digested under pressure using ___________________?
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A. NH3

B. NaOH

C. H2SO4

D. HCl

455. Closeness of packing is maximum in case of ____________________ crystal lattice?
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A. None of these

B. Simple cubic

C. Face centred

D. Body centred

456. Mild steel has _______________ crystal lattice structure?
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A. Orthorhombic

B. Cubic

C. Face centred cubic (fcc)

D. Body centred cubic (bcc)
457. ____________ test is the appropriate test to determine whether a material is ductile or brittle ?
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A. Impact

B. Tensile

C. Cupping

D. Hardness

458. Milk is fat dispersed in water. It is an example of__________________?
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A. Solution

B. Emulsion

C. Gel

D. Suspension

459. Other parameters remaining same, the recrystallisation temperature of an alloy is lowered, when_________________?
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A. Not affected by any of the above parameters

B. Grain size is increased

C. Prior cold deformation is increased

D. Strain rate is increased
460. _____________________ of grey cast iron produces white cast iron?
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A. Slow cooling

B. Rapid cooling

C. Tempering

D. Rapid heating
461. Titanium is added to molten aluminium alloys before casting for the purpose of_____________________?
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A. Increasing corrosion resistance

B. Grain refinement

C. Improving fluidity

D. Reducing porosity

462. Direct conversion of thermal energy to electrical energy is facilitated by the____________________?
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A. Magneto hydrodynamic generator

B. Fuel cells

C. Photo voltaic cell

D. None of these

463. Which of the following is not a principal alloying element for the structural steel ?
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A. Manganese

B. Chromium

C. Molybdenum

D. Nickel

464. Wrought iron does not have__________________?
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A. Ability to hold protective coating

B. Uniform strength in all directions

C. High ductility & corrosion resistance

D. Easily weldable characteristics

465. Metalloids________________?
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A. Are good conductor of heat & electricity

B. Act as electron donors with metals & as electron acceptor with non-metals

C. Are not necessarily solids at room temperature

D. Are compounds that exhibit both metallic & non-metallic properties to some extent and are

E. mplified by elements like germanium, silicon & boron</strong>

466. Which of the following does not discharge the dust collected as a dry solid?
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A. Electrostatic precipitator

B. Gravity settling chamber

C. Bag filter

D. Wet scrubber
467. Alloys having more than 80% copper are generally more______________________?
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A. Corrosion resistant

B. Prone to season cracking

C. Machinable

D. Abrasion resistant

468. Diffusion co-efficient of a metal in a solid solution depends upon its ?
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A. Composition

B. Temperature

C. Both A. & B.

D. Neither A. nor B.

469. Blast furnace slag is mainly molten_________________?
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A. Iron pyrite

B. Sand

C. Magnesium silicate

D. Calcium silicate
470. Carbide tipped cutting tools are manufactured by powder metallurgy techniques and have a composition of_____________________?
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A. 70% aluminium oxide & 30% silica

B. 65% tungsten & 35% zirconium

C. 30% nickel, 15% chromium & 55% tungsten

D. 90% tungsten carbide and 10% cobalt
471. ______________________ temperature remains constant during adiabatic saturation process of unsaturated air ?
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A. Dew point

B. Dry bulb

C. Wet bulb

D. None of these

472. Which of the following is not an explosive ?
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A. TNT

B. Lead azide

C. CMC

D. RDX

473. The heat treatment to which the steel wire containing > 0.25% carbon is subjected to is___________________?
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A. Full annealing

B. None of these

C. Patenting

D. Bright annealing

474. Reduction in the grain size reduces the _________________ of the material?
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A. Creep resistance

B. Fatigue resistance

C. Tensile strength

D. All A, B. & C
475. The transition temperature at which all the ferromagnetic materials become paramagnetic materials is termed as the Curie temperature. Its value for cobalt is ______________ C?
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A. 768

B. 1127

C. 1480

D. 1359

476. A highly elastic material is deformed least on loading and retains its original form on removal of the load. Which of the following is the most elastic material ?
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A. Brass

B. Glass

C. Steel

D. Rubber

477. M10 index of coke indicates its____________________?
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A. Abrasion resistance

B. Hardness

C. Compressive strength

D. Impact strength

478. On oscilloscope screen for dynamic measurement, lissajous diagram is normally used to determine the ______________ of the input signal?
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A. None of these

B. Frequency

C. Amplitude

D. Damping

479. Working of linear variable differential transducer (LVDT) is based on the principle of variable_____________________?
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A. Capacitance

B. None of these

C. Resistance

D. Mutual inductance
480. Metal shots used in shot blasting are made of ______________________?
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A. Bronze

B. Stellite

C. Lead

D. Steel
481. The refrigerant freon-12 is chemically_______________________?
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A. CClF3

B. CCl4F

C. CCl3F

D. CCl2F2
482. Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of ?
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A. Grashoff number & Reynolds number

B. Grashoff number

C. Reynolds number

D. Grashoff number & Prandtl number
483. The difference between gross & net calorific values of fuel is due to the___________________?
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A. Heat lost by radiation

B. Heat carried away by steam from the combustion of hydrogen in the fuel

C. Sensible heat carried away by the flue gases

D. Heat carried away by the steam from the moisture content of the fuel

484. Which of the following is a boiler accessory i.e., not a boiler mounting ?
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A. Feed water pump

B. Blow off cock

C. Stop valve

D. Feed check valve

485. Aluminium is extracted from____________________?
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A. Bauxite

B. None of these

C. Chalcocite

D. Galena

486. __________________ stress cannot be sustained by a fluid in equilibrium ?
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A. Shear

B. Compressive

C. Tensile

D. None of these

487. Which of the following is not an ore of copper ?
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A. Azurite

B. Chalcopyrite

C. Cryolite

D. Malachite

488. Super conduction in metals is observed at a temperature of ________________ K?
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A. About 273

B. >100

C. <100

D. About 373

489. Cobalt 60 is used as a source of _____________ in medical therapy & industrial radiography?
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A. ?-rays

B. ?-rays

C. X-rays

D. ?-rays
490. Cold chisel & hammers are made of_________________?
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A. Mild steel

B. High speed steel

C. Forged steel

D. High carbon steel
491. Hollow shafts can be made as strong as solid shafts by making the twisting moments of both the shafts same. Shafts made by _____________ have residual stresses ?
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A. Forging

B. Cold rolling

C. Casting

D. Hot rolling

492. The product of a commercial direct reduction process is___________________?
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A. Sponge iron

B. Solid iron

C. Iron saturated with carbon

D. Liquid iron

493. More than 95% of _______________ is present in corundum ?
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A. SiO2

B. CaSiO2

C. Al2O3

D. MgO

494. Most important property of steels for use in automobile bodies is the___________________?
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A. Toughness

B. Resilience

C. Yield strength

D. Formability
495. Density in the solid state is slightly less than that in its liquid state, in case of____________________?
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A. Water

B. None of these

C. Mercury

D. Carbon dioxide

496. Pick out the wrong statement ?
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A. Recrystallisation temperature decreases with decrease in strain in a cold worked metal

B. Lead can creep under its own weight at room temperature

C. The electrical conductivity of gold is considerably reduced by alloying additions due to the

D. rease in electron movement

E. With increase in temperature, the electrical conductivity of intrinsic semi-conductor will

497. Projection welding & stud welding is categorised as the _______________ welding?
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A. Thermit

B. Pressure

C. Arc

D. Resistance
498. Which of the following heat treatment processes is usually applied to castings ?
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A. Annealing

B. Normalising

C. Carburising

D. Tempering

499. What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.K respectively ?
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A. 2

B. 40

C. 10

D. 8

500. In a counter flow heat exchanger, hot fluid enters at 170C & leaves at 150C, while the cold fluid enters at 50C & leaves at 70C. The arithmetic mean temperature difference in this case is ______________ C?
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A. 120

B. 20

C. ?

D. 60