Combustion and Flame
Questions about combustion principles, fuel characteristics, flame structure, and environmental effects of burning fuels
Questions
When sand is poured over some burning material, the fire goes off. This is because
- pouring the sand cools the material to a temperature below its ignition temperature
- supply of air is cut off
- sand is a bad conductor of heat
- All of the above
Which of the following is/are essential requirement(s) for producing a fire?
- Fuel
- Air
- Heat
- All of the above
Which of the following is/are the desired characteristic(s) of rocket fuel?
- Light and compact
- High calorific value
- Should burn rapidly
- All of the above
Which of the following has the characteristics of a good fuel?
- Coke
- Butane
- Coal
- Kerosene
Which of the following poisonous gases is produced during incomplete combustion of fuels?
- CO2
- SO2
- NO2
- CO
Acid rain is caused by burning of coal and petroleum because the combustion of these fuels adds to the atmosphere the oxides of
- sulphur
- nitrogen
- carbon
- Both 1 and 2
Which of the following properties is not the characteristic of a good fuel?
- High ignition temperature
- Low cost
- Causes minimum pollution
- Readily available
Which of the following is/are responsible for initiating the combustion process in the matchstick ?
- Antimony sulphide
- Potassium chlorate
- Phosphorous
- Starch and wool
The hottest part of the gas flame is known as
- luminous zone
- dark zone
- blue zone
- non-luminous zone