Fuels and Combustion

41.Abel apparatus is used for those oils, whose flash points are _______°F.

  1. < 120
  2. > 120
  3. > 280
  4. 300-600

Correct answer: (A)
< 120

42.About _________ Nm3 of air will be required for the complete combustion of 2Nm3 of CO.

  1. 2
  2. 3
  3. 4
  4. 5

Correct answer: (D)
5

43.Abrasion index of blast furnace coke should be around _________ percent.

  1. 20
  2. 35
  3. 55
  4. 80

Correct answer: (D)
80

44.Actual flame temperature is always lower than the adiabatic flame temperature, because there is

  1. No possibility of obtaining complete combustion at high temperature
  2. Always loss of heat from the flame
  3. Both (A) and (B)
  4. Neither (A) nor (B)

Correct answer: (C)
Both (A) and (B)

45.Adiabatic flame temperature of a fuel is dependent on the initial temperature of

  1. Fuel
  2. Air
  3. Both (A) & (B)
  4. Neither (A) nor (B)

Correct answer: (C)
Both (A) & (B)

46.Advantages of fluidised bed combustion are

  1. Reduced NOx formation in flue gas
  2. Lower furnace operating temperature
  3. High heat transfer rate
  4. All (A), (B) & (C)

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

47.Air/gas ratio for complete combustion will be the highest for

  1. LPG
  2. Gobar gas
  3. Coke oven gas
  4. Carburetted water gas

Correct answer: (A)
LPG

48.Ammonia content in raw coke oven gas is about _________ gm/Nm3.

  1. 1
  2. 5
  3. 50
  4. 100

Correct answer: (B)
5

49.Anthracite can be used for

  1. Recarbonising steel
  2. Making carbon electrodes
  3. Blending with highly coking coal to check its swelling which helps in saving coke even walls from damage and to produce high strength coke
  4. All (A), (B) and (C)

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

50.Anthracite coal

  1. Contains more volatile matter than bituminous coal
  2. Ignites more easily than bituminous coal
  3. Is essentially a coking coal
  4. Burns with short, bluish, yellow-tipped flame producing very little smoke

Correct answer: (D)
Burns with short, bluish, yellow-tipped flame producing very little smoke

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