G8-PHY-L10 Combustion and Flame

What is combustion?

• A chemical process in which a substance reacts with oxygen to give off heat
• The process of burning a candle
• The act of lighting a matchstick
• The production of light and heat

Which of the following is a combustible substance?

• Water
• Iron
• Wood
• Glass

What is the difference between the burning of a candle and the burning of coal?

• Candle burns with a flame, coal does not
• Candle produces more heat than coal
• Candle burns faster than coal
• Candle produces less smoke than coal

What are the three essential requirements for producing fire?

• Fuel, air, and water
• Fuel, oxygen, and heat
• Fuel, carbon dioxide, and heat
• Fuel, nitrogen, and oxygen

Which zone of a flame is the hottest?

• Dark zone
• Luminous zone
• Non-luminous zone
• All zones have the same temperature

What is the calorific value of a fuel?

• The amount of heat energy produced on complete combustion of 1 kg of fuel
• The temperature at which a fuel catches fire
• The cost of a fuel per unit
• The efficiency of a fuel

Which of the following is a harmful product of burning fuels?

• Carbon dioxide
• Oxygen
• Water vapor
• Sulphur dioxide

What is the best way to control a fire involving electrical equipment?

• Pour water on the fire
• Use a fire extinguisher
• Cover the fire with a blanket
• Let the fire burn out on its own

Which type of combustion produces a sudden burst of flames without any apparent cause?

• Rapid combustion
• Spontaneous combustion
• Explosion
• Slow combustion

Which of the following fuels has the highest calorific value?

• Wood
• Coal
• Petrol
• LPG