Fuels and Combustion MCQs

Question 1

Pick out the wrong statement.

Accepted Answer

Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature

Answer

Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat

Answer

Burning the fuel with theoretically required amount of pure oxygen results in attainment of maximum adiabatic flame temperature

Answer

Adiabatic flame temperatures of actual combustions are always less than the maximum values

Question 2

__________ is used as jet engine fuel.

Accepted Answer

Kerosene

Answer

Petrol

Answer

Diesel

Answer

LPG

Question 3

Gas yield in the Kopper-Totzek coal gasifier is about __________ Nm3/ton coal (ash = 35%).

Accepted Answer

1500

Answer

150

Answer

3500

Answer

5000

Question 4

Coal containing large quantity of __________ are difficult to wash.

Accepted Answer

Inherent mineral matter

Answer

Ash

Answer

Free impurities

Answer

Volatile matter

Question 5

Gobar gas is produced by the __________ of 'gobar' (cow dung).

Accepted Answer

Fermentation

Answer

Hydrolysis

Answer

Oxidation

Answer

Dehydration

Question 6

Preheating of __________ the flame temperature.

Accepted Answer

Either the fuel or the air or both, increases

Answer

The gaseous fuel before combustion decreases

Answer

Combustion air decreases

Answer

Either the fuel or the air does not affect

Question 7

Gross heating value of coal is __________ the net heating value.

Accepted Answer

Higher than

Answer

Lower than

Answer

Same as

Answer

None of these

Question 8

Yield of coke oven gas in low temperature carbonisation of coal is about __________ Nm3/ton of dry coal.

Accepted Answer

160

Answer

60

Answer

500

Answer

750

Question 9

Yield of blast furnace gas is about __________ Nm3/ton of pig iron.

Accepted Answer

2000

Answer

300

Answer

5000

Answer

10000