chemical engineering chemical engineering basics Mcqs
351. _______________ number determines whether the fluid flow in an open channel is super-critical, critical or sub-critical ?
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A. Mach

B. Weber

C. Froude

D. Reynolds

352. Satellite is a _________________ material?
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A. Ferrous

B. Ceramic

C. Cemented carbide

D. Non-ferrous cast alloy cutting tool
353. Tempering of a material does not improve its____________________?
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A. Machinability

B. Internal stress level

C. Toughness

D. Softness

354. The hardenability of steel decreases with__________________?
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A. Decrease in dislocation density

B. Increase in strength

C. Increase in solutionising temperature

D. Decrease in grain size
355. 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. 8.82

B. 10.88

C. 0.95

D. 9.81

356. Transition from laminar flow to turbulent flow in fluid flow through a pipe does not depend upon the___________________?
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A. Diameter of the pipe

B. Density of the fluid

C. Length of the pipe

D. Velocity of the fluid

357. Iron content in Indian iron ore is about _________________ percent?
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A. 80-85

B. 40-45

C. 20-25

D. 60-65
358. Lead pencil contains____________________?
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A. Graphite

B. Lead sulphide

C. Lead

D. Both B. & C.

359. Minimum temperature upto which water can be theoretically cooled down in the cooling tower by evaporative cooling is equal to the ______________ temperature of air?
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A. Saturation

B. Dew point

C. Dry bulb

D. Wet bulb
360. Alloys having more than 80% copper are generally more______________________?
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A. Machinable

B. Corrosion resistant

C. Prone to season cracking

D. Abrasion resistant

361. 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.

362. The Al2O3 content of cryolite in Hall-Heroult cell is maintained between _______________ percent ?
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A. 15-Dec

B. 12-Jun

C. 2-5

D. 18-20

363. In the diving apparatus, helium is used along with oxygen, because it is ____________________?
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A. Lighter than nitrogen

B. Easily available

C. Completely miscible with oxygen

D. Not soluble in blood at high pressure
364. Main constituent of bone ash is____________________?
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A. Ammonium phosphate

B. Ammonium sulphate

C. Calcium phosphate

D. Animal charcoal

365. Use of flux during soldering is done to__________________?
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A. Prevent oxide formation

B. Increase fluidity of solder by lowering its melting temperature

C. Wash away surplus solder

D. Full up the joint gap

366. 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. 2,40,000 J

B. 30,000 J

C. 60,000 J

D. 90,000 J
367. Pearlite comprises of__________________?
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A. 87% cementite & 13% Fe

B. 93.33% ferrite & 6.67% C

C. 87% ferrite & 13% cementite

D. 87% ferrite & 13% C

368. In connection with corrosion of metals, passivation is the process that__________________?
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A. Intensifies deterioration

B. Changes the composition of the metal

C. None of these

D. Inhibits further deterioration
369. 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

370. Function of gear box is to____________________?
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A. Obtain variable speed

B. Produce high torque

C. Increase the speed

D. Reduce the speed

371. Glycerine is used as a coolant in cooling of some engines instead of water, because___________________?
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A. Comparatively less weight of coolant is required

B. Its higher boiling point (290C) increases its heat carrying capacity

C. All a, b & c

D. Smaller radiator can be used

372. 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. Is trebled

B. Decreases by a factor of 1/3

C. Decreases by a factor of 3

D. Remains unchanged
373. Hardening of steel is not possible, unless it is heated _________________ critical point ?
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A. Between the second & third

B. Above the lowest

C. Above the highest

D. Between the first & second

374. Pressure required to increase the density of water by about 1% is ____________________ atmosphere?
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A. 1000

B. 10

C. 200

D. 50

375. Diameter of the rivet to be provided on a 20 mm. thick boiler plate will be ______________ mm?
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A. 40

B. 20

C. 10

D. 30

376. 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>

377. Which of the following has the highest value of refractive index ?
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A. Brine (sea water)

B. Diamond

C. Distilled water

D. Glass

378. Annealing of white cast iron produces _____________________ iron?
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A. Malleable

B. Grey

C. Nodular

D. Spheroidal

379. Maximum consumption of limestone is in the ____________________ industry?
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A. Fertiliser

B. Iron and steel

C. Cement

D. Glass

380. For a thermodynamic system undergoing a process, which of the following pairs best expresses the relationship similar to that expressed by the pressure volume plot ?
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A. Temperature pressure

B. Enthalpy entropy

C. Enthalpy-pressure

D. Temperature entropy
381. If Reynolds number is greater than 1, then the_____________________?
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A. Inertia force is larger than the surface tension force

B. Inertia force is larger than the gravitational force

C. Viscous force is larger than the inertia force

D. Inertia force is larger than the viscous force
382. Which of the following heat treatment processes is usually applied to castings ?
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A. Carburising

B. Tempering

C. Annealing

D. Normalising

383. Use of economiser in a boiler plant reduces the fuel consumption for steam generation by about _______________ percent ?
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A. 50

B. 10

C. 30

D. 1

384. The excess air required for the combustion of pulverized coal is of the order of about _______________ percent ?
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A. 30

B. 5

C. 15

D. 45

385. Brittleness induced due to the presence of sulphur in steel can be reduced by adding______________?
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A. Magnesium

B. Vanadium

C. Copper

D. Manganese
386. Softening of hardened steel is done by its____________________?
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A. Carburising

B. Tempering

C. Annealing

D. Normalising
387. Non-ferrous alloys used for making cutting tools need not have high__________________?
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A. Abrasion resistance

B. Toughness

C. Red hardness

D. Cutting speed

388. Which of the following mainly decides the current to be employed is arc welding ?
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A. Electrode size

B. Welded portion length

C. Plate thickness

D. Voltage across the arc

389. While the bin cards are used in the effective stores management, the queuing theory is associated with the _______________ time ?
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A. Idle

B. Tool replacement

C. Inspection

D. Waiting
390. Which of the following fastening devices has a head at one end and a nut fitted to the other ?
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A. None of these

B. Top bolt

C. Stud

D. Bolt

391. Moist climate is the most favourable factor in the site selection far a_________________?
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A. Coke oven battery

B. Textile factory

C. Steel plant

D. Petroleum refinery

392. The refractory brick which has good thermal shock resistance at high temperature but cracks on cooling below 400C is__________________?
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A. Fireclay

B. Chrome

C. Silica

D. Magnesite

393. The maximum thickness of the metal which can be welded using ultrasonic welding is _____________ mm ?
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A. 25

B. 3

C. 10

D. 0.5

394. Diamagnetic materials___________________?
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A. Are magnetised in direction opposite to the magnetic field

B. Are non-magnetic and cannot be magnetised

C. Are magnetised by eddy currents only

D. Can be magnetised in one direction only

395. Absolute zero pressure can be attained at a temperature of___________________?
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A. 0C

B. 0R

C. None of these

D. 50K

396. Transformer cores are normally made from ______________________?
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A. Al-Ni-Co alloy

B. High purity iron

C. Grain oriented Fe-Si alloy

D. Soft ferrites

397. Cold cracking in the heat affected zone of a high strength steel weld can take place because of the___________________?
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A. Martensite formation

B. Sufficient hydrogen present in the welding arc

C. Retained austenite

D. Relatively high sulphur content in the base metal

398. Recrystallisation temperature of steel is ______________________ C?
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A. 50

B. 300

C. 500

D. 800
399. Which of the following commonly used condenser tube materials has the lowest thermal conductivity ?
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A. Aluminium brass

B. Titanium

C. Admiralty brass

D. Stainless steel
400. Stainless steel is welded using__________________?
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A. Oxy-hydrogen flame

B. Inert gas arc welding

C. Arc welding

D. Oxy-acetylene flame