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प्रश्न
It is difficult to burn a heap of green leaves but dry leaves catch fire easily. Explain
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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.
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