EASY
8th CBSE
IMPORTANT
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The substances which vaporise during burning, give flame.

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Important Questions on Combustion and Flame

EASY
8th CBSE
IMPORTANT
NCERT Exemplar Science - Class 8>Chapter 6 - Combustion and Flame>SHORT ANSWER QUESTIONS>Q 29
 Cracker on ignition produces sound. Why?
MEDIUM
8th CBSE
IMPORTANT
NCERT Exemplar Science - Class 8>Chapter 6 - Combustion and Flame>SHORT ANSWER QUESTIONS>Q 30
What do you understand by fuel efficiency?
EASY
8th CBSE
IMPORTANT
NCERT Exemplar Science - Class 8>Chapter 6 - Combustion and Flame>LONG ANSWER QUESTIONS>Q 31
 You are provided with three watch glasses containing milk, petrol and mustard oil, respectively. Suppose you bring a burning candle near these materials one by one, which material(s) will catch fire instantly and why?
MEDIUM
8th CBSE
IMPORTANT
NCERT Exemplar Science - Class 8>Chapter 6 - Combustion and Flame>LONG ANSWER QUESTIONS>Q 32
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?
MEDIUM
8th CBSE
IMPORTANT
NCERT Exemplar Science - Class 8>Chapter 6 - Combustion and Flame>LONG ANSWER QUESTIONS>Q 33
 What are the three essential requirements to produce fire? How fire extinguisher is useful for controlling the fire.
MEDIUM
8th CBSE
IMPORTANT
NCERT Exemplar Science - Class 8>Chapter 6 - Combustion and Flame>LONG ANSWER QUESTIONS>Q 34
Give two examples each for a solid, liquid and gaseous fuel along with some important uses.
MEDIUM
8th CBSE
IMPORTANT
NCERT Exemplar Science - Class 8>Chapter 6 - Combustion and Flame>LONG ANSWER QUESTIONS>Q 35
 The calorific values of petrol and CNG are 45000 kJ/kg and 50,000 kJ/kg, respectively. If you have vehicle which can run on petrol as well as CNG, which fuel will you prefer and why?
MEDIUM
8th CBSE
IMPORTANT
NCERT Exemplar Science - Class 8>Chapter 6 - Combustion and Flame>LONG ANSWER QUESTIONS>Q 36
 Although wood has a very high calorific value, we still discourage its use as a fuel. Explain.