Fuels and Combustion MCQs

Question 1

Combustion reaction of fuels is a/an __________ reaction.

Accepted Answer

Exothermic

Answer

Auto catalytic

Answer

Endothermic

Answer

None of these

Question 2

Which of the following has the highest flame velocity?

Accepted Answer

H2

Answer

CO

Answer

CH4

Answer

C2H6

Question 3

Which of the following gaseous fuels has the lowest calorific value?

Accepted Answer

Blast furnace gas

Answer

Gobar gas

Answer

Refinery gas

Answer

Converter gas

Question 4

As the C/H ratio of the fuel increases, the amount of CO2 formed on combustion __________ for the same percentage of excess air.

Accepted Answer

Increases

Answer

Decreases

Answer

Remains same

Answer

May increase or decrease depending on the type of fuel

Question 5

Which of the following would require least amount of secondary air for combustion?

Accepted Answer

Coke breeze containing 25% ash and 2% volatile matter

Answer

Anthracite containing 10% volatile matter and 8% ash

Answer

Bituminous coal containing 20% ash and 25% volatile matter

Answer

Semi-bituminous coal containing 25% ash and 20% volatile matter

Question 6

The function of secondary combustion air is to

Accepted Answer

Completely burn the volatile matter

Answer

Pneumatically convey the pulverised coal

Answer

Burn the lumpy coal

Answer

None of these

Question 7

KOH solution used in orsat apparatus absorbs

Accepted Answer

Both A & B

Answer

CO2

Answer

SO2

Answer

Neither A nor B

Question 8

When the coal is heated in absence of air, it is called its

Accepted Answer

Carbonisation

Answer

Deoxidation

Answer

Gasification

Answer

Coalification

Question 9

During combustion of gaseous fuels, deficiency of air

Accepted Answer

Lengthens the flame

Answer

Tends to shorten the flame

Answer

Does not affect the flame length

Answer

Increases the flame temperature