VERY SHORT ANSWER QUESTIONS (VSAQ) :
1. On what factors calorific value of a fuel depends ?
2. Wet paper does not burn while a dry paper catches fire
3. Why charcoal is burnt in a hearth?
Petrol does not catch fire on its own at room temperatur
SHORT ANSWER QUESTIONS (SAQ) :
Why dry leaves burn easily but green leaves are difficu
Answers
Answer:
Explanation:
1.The amount of heat produced by the complete burning of 1kg of a fuel is called its calorific value. The calorific value of a fuel depends upon the nature of the fuel and the relative proportions of the elements present .
2.It is difficult to burn a wet paper because it contains water. A lot of heat is required to evaporate this water( to dry the paper). Only After the water is completely removed and the paper is totally dry, the heat is used to reach the ignition point of the paper from where it then starts to burn
3.Green leaves contain moisture whereas dry leaves do not contain moisture as a result, the ignition temperature of green leaves is higher than that of dry leaves. Due to this reason, it is difficult to burn a heap of green leaves but dry leaves catch fire easily.