Fuel

Question 1

What is a fuel?

Answer 1

Fuel is a substance that can burn in the presence of air and produce heat in a controlled manner.

Question 2

Classify fuels on the basis of their source.

Answer 2

1. primary: used in the same form as they occur in nature.
2. Secondary: obtained from natural fuels through various physical and chemical processes

Question 3

Classify fuels in the basis of their physical state.

Answer 3

1. Solid fuels such as wood and coal leave some ash or residue after combustion and need large space for storage
2. Liquid fuels such as kerosene, petroleum and diesel exist as liquid in room temperature and do no leave behind any residue after combustion. They are usually made of hydrocarbons.
3. Gaseous fuels such as natural gas and coal gas exist as gases in room temperature.

Question 4

What is Calorific value of a fuel?

Answer 4

Heat liberated when one gram of fuel burns completely in oxygen.

Question 5

What is the SI unit of calorific value?

Answer 5

Joule/kg

Question 6

What are the characteristics of an ideal fuel.

Answer 6

1. Must have a moderate ignition temperature
2. Must not release harmful gases on combustion
3. Must be readily available and economical
4. Should be easy to store and transport
5. Should have high calorific value and moderate rate of combustion