chemical engineering fuels and combustion MCQs – Page 10

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 Review each marked answer and report any item that may be outdated or unclear.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
181. Yield of pitch from distillation of high temperature tar is around _____________ percent?
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A. 25

B. 65

C. 90

D. 10

182. Washing of coal decreases its_________________?
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A. Caking index

B. Mineral matter content

C. Ash content

D. Both B. and C.

183. Gross heating value of coal is ______________ the net heating value?
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A. None of these

B. Lower than

C. Higher than

D. Same as

184. Presence of free moisture in coal is most disadvantageous during_________________?
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A. Combustion of fire slacks on the grates

B. None of these

C. Handling (e.g. when emptying wagons)

D. Its pulverisation (as it requires more power)
185. __________ is used as jet engine fuel ?
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A. Kerosene

B. LPG

C. Petrol

D. Diesel

186. Artificial draught produced by a fan can be controlled by the___________________?
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A. Damper

B. Variation in the pitch of the fan blades

C. Speed of the fan

D. All A., B. and C.
187. Out of the following, which is the most important parameter for the blast furnace grade coke ?
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A. Moisture content

B. Volatile matter content

C. CSR & CRI

D. Ash content

188. A travelling grate stoker is meant for the efficient burning of ______________ coal?
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A. Caking

B. Pulverised

C. Non-caking

D. High ash

189. Pick out the wrong statement ?
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A. L.P.G. is lighter than air

B. Main constituents of LPG are propane and butane

C. C.V. of LPG is about 26000 kcal/Nm3 (11500 kcal/kg)

D. C.V. of natural gas is about 10000 KCal/Nm3

190. Froth floatation is used for_________________?
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A. Washing fine coal dust (< 0.5 mm size)

B. Washing lump coal (> 80 mm size)

C. All A., B. and C.

D. Removing ash from the coal based on difference in specific gravity of coal and ash

191. Kopper-Totzek coal gasifier (installed in a coal based nitrogeneous fertiliser plant) employs a/an ______________ bed gasifier?
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A. Moving

B. Fluidised

C. Entrained

D. Fixed

192. Which of the following is not a manufactured fuel ?
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A. Coke breeze

B. Colloidal fuels

C. Soft coke

D. Charcoal

193. Naphthalene is used for making_________________?
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A. Insecticides (e.g. moth balls)

B. Unsaturated polyesters

C. All A., B. and C.

D. Drug intermediates e.g. ?-naphthol

194. Higher efficiency in the combustion of solid fuel cannot be achieved by________________?
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A. Supplying correct quantity of combustion air

B. Proper fuel preparation

C. Keeping the flue gas exhaust temperature very high

D. Adopting efficient-fuel firing technique & equipment

195. With increase in the time of carbonisation at a particular temperature (say 1000C), the ______________ percentage in coke oven gas increases?
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A. Unsaturated hydrocarbons

B. Methane

C. All A., B. and C.

D. Hydrogen
196. A certain thickness of the coal, if stored unscientifically on soft (katcha) ground having no metallic/concrete flooring gets sunked into the ground, which is termed as the carpet loss. The carpet loss may be of the order of ______________ cms?
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A. 5 to 15

B. 1 to 2

C. 20 to 40

D. 3 to 4

197. Undercharging of coal in the by-product coke ovens results in ____________________?
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A. Increase in the c.v. of coke oven gas

B. Decrease in the c.v. of coke oven gas

C. No change in the c.v. of coke oven gas

D. Increase in its throughput

198. Wobbe index is a characteristic of__________________?
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A. Fat coals

B. Liquid fuels

C. Gaseous fuels

D. Solid fuels

199. Pick out the correct statement ?
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A. With increase in oxygen content, moisture holding capacity of coal increases and the caking power decreases

B. Oxygen content decreases from lignite to bituminous coal as the coalification increases

C. All A., B. and C.

D. The less the oxygen content, better is the coal, as it reduces the calorific value

200. Percentage of nitrogen in blast furnace gas may be around__________________?
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A. 5

B. 55

C. 25

D. 80