Paper 3 Multiple Choice Questions - Chapter 3: Combustion

What is the main component of Natural Gas used in the UK?

• Ethane

• Methane

• Propane

• Butane

Which gas family includes Propane and Butane?

• 1st Family

• 2nd Family

• 3rd Family

• Manufactured Gas

What is the typical specific gravity of Natural Gas?

• 1.0

• 0.6–0.7

• 1.5

• 2.0

Which of the following gases is heavier than air?

• Methane

• Propane

• Hydrogen

• Oxygen

What is the formula for calculating the Wobbe Number?

• Specific Gravity ÷ Calorific Value

• Calorific Value ÷ Specific Gravity

• CO ÷ CO₂

• Flue Temperature ÷ Room Temperature

What are the flammability limits of Methane?

• 1.4%–9.3%

• 5%–15%

• 1.7%–10.9%

• 2%–12%

What is the ignition temperature range of Butane?

• 632–704°C

• 493–547°C

• 413–527°C

• 300–400°C

What are the products of complete combustion of Methane?

• CO and H2O

• CO2 and H2O

• CO2 and CO

• CH4 and O2

What is stoichiometric combustion?

• Combustion with excess air

• Combustion with no air

• Combustion with exact air-fuel ratio

• Combustion with high CO levels

Which of the following is a sign of incomplete combustion?

• A) Blue flame

• B) Clear heat exchanger

• C) Yellow flame

• D) Low CO levels