Fuels and Combustion

211.In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of

  1. Transportation of coal
  2. Drying of coal
  3. Combustion of coal by supplying it around the burner
  4. Preheating the primary air

Correct answer: (C)
Combustion of coal by supplying it around the burner

212.In flue gas analysis by Orsat's apparatus, carbon dioxide is absorbed by

  1. Potassium hydroxide
  2. Dilute potassium carbonate
  3. Cuprous chloride
  4. Alkaline pyrogallol solution

Correct answer: (A)
Potassium hydroxide

213.In flue gas analysis by Orsat's apparatus, carbon monoxide is absorbed by

  1. Cuprous chloride
  2. Potassium hydroxide
  3. Alkaline pyrogallol solution
  4. None of these

Correct answer: (A)
Cuprous chloride

214.In flue gas analysis by Orsat's apparatus, oxygen is absorbed by

  1. Potassium hydroxide
  2. Cuprous chloride
  3. Alkaline pyrogallol solution
  4. None of these

Correct answer: (C)
Alkaline pyrogallol solution

215.In general, the limit of inflammability/explosion limit of fuel gases is widened by the

  1. Increase in gas pressure
  2. Increase in temperature (i.e. preheating)
  3. Use of pure oxygen for combustion instead of air
  4. All (A), (B) & (C)

Correct answer: (D)
All (A), (B) & (C)

216.In high temperature carbonisation (as compared to low temperature carbonisation) of coal

  1. Coke oven gas yield is more
  2. Tar yield is less but free carbon in tar is more
  3. Calorific value of coke oven gas is less
  4. All (A), (B) and (C)

Correct answer: (D)
All (A), (B) and (C)

217.In high temperature carbonisation (as compared to low temperature carbonisation) of coal, the

  1. Gas yield is less
  2. Tar yield is more
  3. Ignition temperature of coke produced is less
  4. Aromatic content of tar produced is more

Correct answer: (D)
Aromatic content of tar produced is more

218.In high temperature carbonisation of coal compared to low temperature carbonisation

  1. Yield of ammonia is less
  2. Aromatic content of tar is low
  3. H2 content in the coke oven gas is more
  4. Calorific value of the coke oven gas is lower

Correct answer: (C)
H2 content in the coke oven gas is more

219.In low temperature carbonisation (as compared to high temperature carbonisation) of coal

  1. Ammonia yield is more
  2. Aliphatic tar is produced
  3. Free carbon in tar is more
  4. All (A), (B) and (C)

Correct answer: (B)
Aliphatic tar is produced

220.In low temperature carbonisation of coal as compared to high temperature carbonisation _________ produced is less.

  1. Difference in gross & net calorific value of the coke oven gas
  2. Free carbon content in tar
  3. Yield percentage of coke
  4. Yield of ammonia present in coke oven gas

Correct answer: (A)
Difference in gross & net calorific value of the coke oven gas

Previous
Page 22 of 48
Next
Copyright © EngineeringMCQ.com