The dark zone of candle flame is

• outer zone of complete combustion

• zone of partial combustion

• inner Zone

• none of the above

List conditions under which combustion can take place.

Burning of wood and coal causes __________ of air.

A liquid fuel, used in homes is __________

Fuel must be heated to its __________ before it starts burning.

Fire produced by oil cannot be controlled by ___________ .

Explain how the use of CNG in automobiles has reduced pollution in our cities.

Compare LPG and wood as fuels.

Give reasons :

Water is not used to control the fire involving electrical equipment.

Give reasons :

LPG is a better domestic fuel than wood.

Give reasons :

Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.