Question

cai
nitrogen dioxide
sulphur dioxide
5. Answer the following questions in brief.
1.
Define the term 'combustible materiall? Give two examples of co
materials.
2.
State the three conditions that are needed for combustion to take
3.
State the condition under which 'slow combustion' of a material ta
4.
Define 'calorific value of a fuel'.
5.
State any two characteristics of an ideal fuel.
6. Why is water not used in controlling electrical fires?
I.
Answer the following questions.​

Answer 1

The materials which on heating in presence of air/oxygen catches fire easily and produce heat and light energy are called Combustible Substance. Example - Petrol,Coal.

2.Three things are required in proper combination before ignition and combustion can take place---Heat, Oxygen and Fuel.

There must be Fuel to burn.

There must be Air to supply oxygen.

There must be Heat (ignition temperature) to start and continue the combustion process.