chemical engineering fuels and combustion MCQs – Page 23

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 Review each marked answer and report any item that may be outdated or unclear.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

441. Coal tar (produced by high temperature carbonization) is the main source of_________?
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A. Aromatic compounds

B. Paraffins

C. Aliphatic compounds

D. Olefins

442. Incomplete combustion of fuel in the furnace is judged by high _____________ of the flue gases?
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A. Dew point

B. CO2 content

C. O2 content

D. CO content

443. Ignition temperature of a fuel in air is ______________ that in pure oxygen?
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A. Equal to

B. Either more or less; depends on the type of fuel

C. Less than

D. More than

444. Producer gas containing least amount of tar is produced by the_________________?
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A. High pressure gasification of coal (e.g. in Lurgi gasifier)

B. Partial combustion of large size (< 50 mm) coke

C. Partial combustion of coal

D. Atmospheric pressure gasification of coal (e.g., in Kopper-Totzek gasifier)

445. Calorific values of both the solid as well as the liquid fuels can be determined by ______________ calorimeter?
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A. Junkers

B. Bomb

C. Boys

D. None of these

446. The function of secondary combustion air is to ______________________?
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A. Pneumatically convey the pulverised coal

B. None of these

C. Burn the lumpy coal

D. Completely burn the volatile matter

447. Turndown ratio of a gas burner is equal to the __________________ ?
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A. Maximum to minimum heat input ratio

B. Maximum to minimum permissible gas flow rate

C. Both A. & B.

D. Minimum to maximum heat input ratio

448. The liquid used for the washing of coal in an industrial coal washery is a mixture of water and ____________________?
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A. Carbon tetrachloride

B. Sand (40%)

C. None of these

D. Mineral oil of high viscosity & specific gravity (1.6)

449. Which of the following is used for making the explosive TNT? ?
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A. Pyridine

B. Cerosote

C. Benzol

D. Toluene

450. Pick out the wrong statement ?
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A. High concentration of oxygen in flue gas means high stack loss

B. The ratio of fixed carbon to volatile matter percentage in coal is called its fuel ratio

C. Gaseous fuels require the least % excess air for complete combustion

D. Calorific value of natural gas is more than that of LPG

451. During coal carbonisation process, the conversion of semi-coke to coke is accompanied by an increase in the _______________ of the mass?
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A. Electrical resistivity

B. Porosity

C. Density

D. None of these

452. Higher percentage of ash in coal meant for the production of metallurgical grade coke ___________________?
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A. None of these

B. Decreases the abrasion resistance of coke

C. Decreases the hardness of coke

D. Causes brittleness in steel

453. Safe condition for storage of high V.M. bituminous coal is that ___________________?
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A. Height of the coal heap should be < 3 metres

B. Maximum 200 tons should be stored in a heap

C. Both A. and B.

D. Neither A. nor B.

454. Yield of coke oven gas in low temperature carbonisation of coal is about ______________ Nm3 /ton of dry coal?
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A. 750

B. 500

C. 60

D. 160

455. The combustion reaction, C + O2 = CO2, is ___________________?
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A. Autocatalytic

B. None of these

C. Endothermic

D. Exothermic

456. Pick out the wrong statement ?
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A. Maximum yield of naphthalene is obtained on distillation of crude oil

B. called its flash point</strong>

C. LPG is also used as fuel for automobiles & small furnaces and for cutting & welding of

D. Each ton of petroleum oil on distillation produces about 30-50 Nm3 of gas

E. als

F. The minimum temperature, at which a petroleum oil vapor catches fire and continues to burn,

457. A coal containing very high percentage of durain is called ______________ coal?
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A. Splint

B. Non-banded

C. Bright

D. Boghead

458. Fussain _____________________?
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A. coal

B. Is friable, charcoal like substance

C. Is non-coking, but when blended with highly coking coal, controls its swelling and produces

D. All A., B. and C.

E. h strength coke on carbonisation

F. Has highest fixed carbon and lowest volatile matter content of all the four banded components

459. By-products are _____________ recovered in Beehive ovens ?
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A. Partially

B. Negligibly

C. Fully

D. Not at all

460. Blast furnace gas burns with a bluish flame, because of the presence of____________________?
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A. CO

B. S

C. CH4

D. CO2

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