chemical engineering fuels and combustion MCQs – Page 14

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 Review each marked answer and report any item that may be outdated or unclear.

chemical engineering fuels and combustion Mcqs

261. Ionisation potential applied across the electrodes of electrostatic tar precipitator is around_____________________?
0

A. 60 KV AC

B. 230 V AC

C. 60 KV DC

D. 230 V DC

262. Heat penetration rate in narrow coke ovens in high temperature carbonisation of coal is around ______________ cm/hr?
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A. 20

B. 2.5

C. 10

D. 0.5

263. Temperature of preheated air used for the transportation of pulverised coal through pipes to the burner of a boiler furnace is restricted to a maximum limit of about 300 C to avoid the___________________?
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A. Chances of clinker formation

B. Incomplete combustion of coal

C. Requirement of large volume combustion chamber

D. Risk of explosion

264. Preheating of ______________ the flame temperature?
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A. Either the fuel or the air does not affect

B. Combustion air decreases

C. Either the fuel or the air or both, increases

D. The gaseous fuel before combustion decreases

265. A coal containing high amount of volatile matter will have__________________?
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A. High fusion point of its ash

B. Low adiabatic flame temperature

C. Low ignition temperature

D. Very little ash content

266. Natural draught produced by a chimney depends upon the _____________________?
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A. Density of the chimney gases

B. Height of the chimney

C. Both A. and B.

D. Neither A. nor B.

267. Coke oven gas compared to blast furnace gas is________________?
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A. Lighter

B. Less poisonous

C. More explosive and inflammable

D. All A., B. and C.

268. The maximum adiabatic flame temperature in air as compared to that in pure oxygen is_______________?
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A. Either lower or higher, depends on the type of fuel

B. Much higher

C. Much lower

D. Same

269. Hard coke is manufactured from___________________?
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A. Anthracite

B. Lignite

C. Semi-anthracite

D. Bituminous coal

270. A particular coal is said to be free burning when it __________________?
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A. Burns completely

B. Gives smokeless burning

C. Shows little or no fusing action

D. None of these

271. Volatile matter content of metallurgical coke may be around ______________ percent?
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A. 30-33

B. 15-Oct

C. 1-2

D. 22-26

272. If the specific heat of gaseous products of combustion of a fuel is high, the abiabatic flame temperature will be_____________?
0

A. High

B. None of these

C. Low

D. Very high, if the fuel is of low calorific value

273. The lowest temperature, at which a solid fuel produces enough vapors to support continuous combustion, is called ?
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A. Fire point

B. Kindling temperature

C. Burning temperature

D. Smoke point

274. Gross & net calorific value is the same for___________________?
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A. Coke oven gas

B. Blast furnace gas

C. L.D. converter gas

D. None of these

275. _____________ present in coal is not determined in its ultimate analysis ?
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A. Total carbon

B. Nitrogen

C. Hydrogen

D. Fixed carbon

276. A good quality coal should have ___________________?
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A. None of these

B. Low fusion point of ash

C. High ash content

D. High sulphur

277. Which of the following gaseous fuels is likely to have the highest gross calorific value ?
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A. Sewage gas

B. Natural gas

C. LPG

D. Producer gas

278. Coal containing large quantity of _______________ are difficult to wash?
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A. Volatile matter

B. Free impurities

C. Ash

D. Inherent mineral matter

279. (64-132) rank coal (ASTM) means a coal with 64%___________________?
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A. Ash and a heating value of 13, 200 BTU/1b

B. None of these

C. Fixed carbon and a heating value of 132 BTU/1b

D. Fixed carbon and having a heat value of 13, 200 BTU/1b

280. A coal that softens and fuses on heating is_________________?
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A. Classified

B. Caking

C. Non-caking

D. Carbonised

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