Advertisements
Advertisements
प्रश्न
It is difficult to burn a heap of green leaves but dry leaves catch fire easily. Explain
उत्तर
It is difficult to burn a heap of green leaves but dry leaves catch fire easily because green leaves contain a lot of water. This absorbs the heat given to burn them and evaporates and does not let the temperature of the leaves rise to their ignition temperature. Due to this, green leaves do not catch fire until all the water evaporates and their temperature reaches their ignition temperature.
Dry leaves catch fire quickly because of the absence of water because the heat given to burn them quickly raises their temperature to their ignition temperature and they start burning.
APPEARS IN
संबंधित प्रश्न
Fire produced by oil cannot be controlled by ______.
Give reasons.
Water is not used to control fires involving electrical equipment.
Which zone of a flame does a goldsmith use for melting gold and silver and why?
Choose the incorrect statement from the following.
Forest fires are usually due to
Some words (underlined) in the following sentence is jumbled up. Write them in their correct form.
Chittsmack does not burn by itself.
State whether the following statement is True/False.
Carbon dioxide is an excellent fire extinguisher.
Write True/False against the following statement and also correct the false statement.
Water is the best extinguisher for fires involving electrical equipment.
Manu was heating oil to fry potato chips. The cooking oil all of a sudden caught fire, he poured water to extinguish the fire. Do you think, this action was suitable? If yes, why? If not, why not? In such a condition what should Manu have done?
What are the three essential requirements to produce fire? How fire extinguisher is useful for controlling the fire?
Give an example of class B fires.
