Compare LPG and wood as fuels.

Give reasons.

(a) Water is not used to control fires involving electrical equipment.

(b) LPG is a better domestic fuel than wood.

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

Name the unit in which the calorific value of a fuel is expressed.

Explain how CO₂ is able to control fires.