Q. 5. 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 aluminum pipe does not.
Q.6. Make a labeled diagram of a candle flame
Q.7. Name the unit in which the calorific value of a fuel is expressed.
Q.8. Explain how CO2 is able to control fires.
Q.9. Why it is difficult to burn a heap of green leaves but dry leaves catch fire easily
Q.10. Which zone of a flame does a goldsmith use for melting gold and silver and why
Q.11. In an experiment, 4.5 kg of fuel was completely burnt. The heat produced was measured to be 180,000 kJ. Calculate the calorific value of the fuel.
Q.12. Can the process of rusting be called combustion Discuss
Q.13. In which zone of the candle flame, does water gets heated in a shorter time