Fuels and Combustion Quiz

What is the primary purpose of a hydrometer in measuring liquid fuels?

• To assess flash point

• To measure viscosity

• To calculate calorific value

• To determine density

Which property of liquid fuels is defined as the ratio of the mass of the fuel to its volume?

• Calorific value

• Specific gravity

• Density

• Viscosity

What is the significance of pre-heating furnace oil before burning?

• To increase its density

• To improve atomization

• To reduce flash point

• To decrease viscosity

Which of the following is a disadvantage of high sulfur content in fuel oil?

• Improved combustion efficiency

• Risk of corrosion

• Increased calorific value

• Lower viscosity

What is the typical calorific value of kerosene?

• 10,500 kCal/kg

• 11,100 kCal/kg

• 10,800 kCal/kg

• 10,700 kCal/kg

How does moisture content in coal affect its combustion efficiency?

• Improves combustion speed

• Increases heat content

• Decreases heat content

• Has no effect

What is the primary component of natural gas?

• Methane

• Ethane

• Butane

• Propane

What is the typical stoichiometric air-fuel ratio for burning coal?

• 7-8 kg of air per kg of coal

• 10 kg of air per kg of coal

• 5 kg of air per kg of coal

• 14.1 kg of air per kg of coal

What is the effect of excess air on combustion efficiency?

• Increases efficiency

• Improves fuel quality

• No effect

• Decreases efficiency

Which of the following is a method to reduce fines in coal combustion?

• Decreasing air supply

• Increase moisture content

• Use of higher temperatures

• Conditioning with water